PART II.
I have now enumerated the chief facts which every one would desire to see connected by some intelligible bond. This can be done, if we make the following assumptions, and much may be advanced in favour of the chief one. The secondary assumptions can likewise be supported by various physiological considerations. It is universally admitted that the cells or units of the body increase by self-division or proliferation, retaining the same nature, and that they ultimately become converted into the various tissues and substances of the body. But besides this means of increase I assume that the units throw off minute granules which are dispersed throughout the whole system; that these, when supplied with proper nutriment, multiply by self-division, and are ultimately developed into units like those from which they were originally derived. These granules may be called gemmules. They are collected from all parts of the system to constitute the sexual elements, and their development in the next generation forms a new being; but they are likewise capable of transmission in a dormant state to future generations and may then be developed. Their development depends on their union with other partially developed or nascent cells which precede them in the regular course of growth. Why I use the term union, will be seen when we discuss the direct action of pollen on the tissues of the mother-plant. Gemmules are supposed to be thrown off by every unit, not only during the adult state, but during each stage of development of every organism; but not necessarily during the continued existence of the same unit. Lastly, I assume that the gemmules in their dormant state have a mutual affinity for each other, leading to their aggregation into buds or into the sexual elements. Hence, it is not the reproductive organs or buds which generate new organisms, but the units of which each individual is composed. These assumptions constitute the provisional hypothesis which I have called Pangenesis. Views in many respects similar have been propounded by various authors.[[42]]
Before proceeding to show, firstly, how far these assumptions are in themselves probable, and secondly, how far they connect and explain the various groups of facts with which we are concerned, it may be useful to give an illustration, as simple as possible, of the hypothesis. If one of the Protozoa be formed, as it appears under the microscope, of a small mass of homogeneous gelatinous matter, a minute particle or gemmule thrown off from any part and nourished under favourable circumstances would reproduce the whole; but if the upper and lower surfaces were to differ in texture from each other and from the central portion, then all three parts would have to throw off gemmules, which when aggregated by mutual affinity would form either buds or the sexual elements, and would ultimately be developed into a similar organism. Precisely the same view may be extended to one of the higher animals; although in this case many thousand gemmules must be thrown off from the various parts of the body at each stage of development; these gemmules being developed in union with pre-existing nascent cells in due order of succession.
Physiologists maintain, as we have seen, that each unit of the body, though to a large extent dependent on others, is likewise to a certain extent independent or autonomous, and has the power of increasing by self-division. I go one step further, and assume that each unit casts off free gemmules which are dispersed throughout the system, and are capable under proper conditions of being developed into similar units. Nor can this assumption be considered as gratuitous and improbable. It is manifest that the sexual elements and buds include formative matter of some kind, capable of development; and we now know from the production of graft-hybrids that similar matter is dispersed throughout the tissues of plants, and can combine with that of another and distinct plant, giving rise to a new being, intermediate in character. We know also that the male element can act directly on the partially developed tissues of the mother-plant, and on the future progeny of female animals. The formative matter which is thus dispersed throughout the tissues of plants, and which is capable of being developed into each unit or part, must be generated there by some means; and my chief assumption is that this matter consists of minute particles or gemmules cast off from each unit or cell.[[43]]
But I have further to assume that the gemmules in their undeveloped state are capable of largely multiplying themselves by self-division, like independent organisms. Delpino insists that to “admit of multiplication by fissiparity in corpuscles, analogous to seeds or buds . . . is repugnant to all analogy.” But this seems a strange objection, as Thuret[[44]] has seen the zoospore of an alga divide itself, and each half germinated. Haeckel divided the segmented ovum of a siphonophora into many pieces, and these were developed. Nor does the extreme minuteness of the gemmules, which can hardly differ much in nature from the lowest and simplest organisms, render it improbable that they should grow and multiply. A great authority, Dr. Beale,[[45]] says “that minute yeast cells are capable of throwing off buds or gemmules, much less than the 1/100000 of an inch in diameter;” and these he thinks are “capable of subdivision practically ad infinitum.”
A particle of small-pox matter, so minute as to be borne by the wind, must multiply itself many thousandfold in a person thus inoculated; and so with the contagious matter of scarlet fever.[[46]] It has recently been ascertained[[47]] that a minute portion of the mucous discharge from an animal affected with rinderpest, if placed in the blood of a healthy ox, increases so fast that in a short space of time “the whole mass of blood, weighing many pounds, is infected, and every small particle of that blood contains enough poison to give, within less than forty-eight hours, the disease to another animal.”
The retention of free and undeveloped gemmules in the same body from early youth to old age will appear improbable, but we should remember how long seeds lie dormant in the earth and buds in the bark of a tree. Their transmission from generation to generation will appear still more improbable; but here again we should remember that many rudimentary and useless organs have been transmitted during an indefinite number of generations. We shall presently see how well the long-continued transmission of undeveloped gemmules explains many facts.
As each unit, or group of similar units, throughout the body, casts off its gemmules, and as all are contained within the smallest ovule, and within each spermatozoon or pollen-grain, and as some animals and plants produce an astonishing number of pollen-grains and ovules,[[48]] the number and minuteness of the gemmules must be something inconceivable. But considering how minute the molecules are, and how many go to the formation of the smallest granule of any ordinary substance, this difficulty with respect to the gemmules is not insuperable. From the data arrived at by Sir W. Thomson, my son George finds that a cube of 1/10000 of an inch of glass or water must consist of between 16 million millions, and 131 thousand million million molecules. No doubt the molecules of which an organism is formed are larger, from being more complex, than those of an inorganic substance, and probably many molecules go to the formation of a gemmule; but when we bear in mind that a cube of 1/10000 of an inch is much smaller than any pollen-grain, ovule or bud, we can see what a vast number of gemmules one of these bodies might contain.
The gemmules derived from each part or organ must be thoroughly dispersed throughout the whole system. We know, for instance, that even a minute fragment of a leaf of a Begonia will reproduce the whole plant; and that if a fresh-water worm is chopped into small pieces, each will reproduce the whole animal. Considering also the minuteness of the gemmules and the permeability of all organic tissues, the thorough dispersion of the gemmules is not surprising. That matter may be readily transferred without the aid of vessels from part to part of the body, we have a good instance in a case recorded by Sir J. Paget of a lady, whose hair lost its colour at each successive attack of neuralgia and recovered it again in the course of a few days. With plants, however, and probably with compound animals, such as corals, the gemmules do not ordinarily spread from bud to bud, but are confined to the parts developed from each separate bud; and of this fact no explanation can be given.
The assumed elective affinity of each gemmule for that particular cell which precedes it in due order of development is supported by many analogies. In all ordinary cases of sexual reproduction, the male and female elements certainly have a mutual affinity for each other: thus, it is believed that about ten thousand species of Compositæ exist, and there can be no doubt that if the pollen of all these species could be simultaneously or successively placed on the stigma of any one species, this one would elect with unerring certainty its own pollen. This elective capacity is all the more wonderful, as it must have been acquired since the many species of this great group of plants branched off from a common progenitor. On any view of the nature of sexual reproduction, the formative matter of each part contained within the ovules and the male element act on each other by some law of special affinity, so that corresponding parts affect one another; thus, a calf produced from a short-horned cow by a long-horned bull has its horns affected by the union of the two forms, and the offspring from two birds with differently coloured tails have their tails affected.
The various tissues of the body plainly show, as many physiologists have insisted,[[49]] an affinity for special organic substances, whether natural or foreign to the body. We see this in the cells of the kidneys attracting urea from the blood; in curare affecting certain nerves; Lytta vesicatoria the kidneys; and the poisonous matter of various diseases, as small-pox, scarlet-fever, hooping-cough, glanders, and hydrophobia, affecting certain definite parts of the body.
It has also been assumed that the development of each gemmule depends on its union with another cell or unit which has just commenced its development, and which precedes it in due order of growth. That the formative matter within the pollen of plants, which by our hypothesis consists of gemmules, can unite with and modify the partially developed cells of the mother-plant, we have clearly seen in the section devoted to this subject. As the tissues of plants are formed, as far as is known, only by the proliferation of pre-existing cells, we must conclude that the gemmules derived from the foreign pollen do not become developed into new and separate cells, but penetrate and modify the nascent cells of the mother-plant. This process may be compared with what takes place in the act of ordinary fertilisation, during which the contents of the pollen-tubes penetrate the closed embryonic sac within the ovule, and determine the development of the embryo. According to this view, the cells of the mother-plant may almost literally be said to be fertilised by the gemmules derived from the foreign pollen. In this case and in all others the proper gemmules must combine in due order with pre-existing nascent cells, owing to their elective affinities. A slight difference in nature between the gemmules and the nascent cells would be far from interfering with their mutual union and development, for we well know in the case of ordinary reproduction that such slight differentiation in the sexual elements favours in a marked manner their union and subsequent development, as well as the vigour of the offspring thus produced.
Thus far we have been able by the aid of our hypothesis to throw some obscure light on the problems which have come before us; but it must be confessed that many points remain altogether doubtful. Thus it is useless to speculate at what period of development each unit of the body casts off its gemmules, as the whole subject of the development of the various tissues is as yet far from clear. We do not know whether the gemmules are merely collected by some unknown means at certain seasons within the reproductive organs, or whether after being thus collected they rapidly multiply there, as the flow of blood to these organs at each breeding season seems to render probable. Nor do we know why the gemmules collect to form buds in certain definite places, leading to the symmetrical growth of trees and corals. We have no means of deciding whether the ordinary wear and tear of the tissues is made good by means of gemmules, or merely by the proliferation of pre-existing cells. If the gemmules are thus consumed, as seems probable from the intimate connection between the repair of waste, re-growth, and development, and more especially from the periodical changes which many male animals undergo in colour and structure, then some light would be thrown on the phenomena of old age, with its lessened power of reproduction and of the repair of injuries, and on the obscure subject of longevity. The fact of castrated animals, which do not cast off innumerable gemmules in the act of reproduction, not being longer-lived than perfect males, seems opposed to the belief that gemmules are consumed in the ordinary repair of wasted tissues; unless indeed the gemmules after being collected in small numbers within the reproductive organs are there largely multiplied.[[50]]
That the same cells or units may live for a long period and continue multiplying without being modified by their union with free gemmules of any kind, is probable from such cases as that of the spur of a cock which grew to an enormous size when grafted into the ear of an ox. How far units are modified during their normal growth by absorbing peculiar nutriment from the surrounding tissues, independently of their union with gemmules of a distinct nature, is another doubtful point.[[51]] We shall appreciate this difficulty by calling to mind what complex yet symmetrical growths the cells of plants yield when inoculated by the poison of a gall-insect. With animals various polypoid excrescences and tumours are generally admitted[[52]] to be the direct product, through proliferation, of normal cells which have become abnormal. In the regular growth and repair of bones, the tissues undergo, as Virchow remarks,[[53]] a whole series of permutations and substitutions. “The cartilage cells may be converted by a direct transformation into marrow-cells, and continue as such; or they may first be converted into osseous and then into medullary tissue; or lastly, they may first be converted into marrow and then into bone. So variable are the permutations of these tissues, in themselves so nearly allied, and yet in their external appearance so completely distinct.” But as these tissues thus change their nature at any age, without any obvious change in their nutrition, we must suppose in accordance with our hypothesis that gemmules derived from one kind of tissue combine with the cells of another kind, and cause the successive modifications.
We have good reason to believe that several gemmules are requisite for the development of one and the same unit or cell; for we cannot otherwise understand the insufficiency of a single or even of two or three pollen-grains or spermatozoa. But we are far from knowing whether the gemmules of all the units are free and separate from one another, or whether some are from the first united into small aggregates. A feather, for instance, is a complex structure, and, as each separate part is liable to inherited variations, I conclude that each feather generates a large number of gemmules; but it is possible that these may be aggregated into a compound gemmule. The same remark applies to the petals of flowers, which are sometimes highly complex structures, with each ridge and hollow contrived for a special purpose, so that each part must have been separately modified, and the modifications transmitted; consequently, separate gemmules, according to our hypothesis, must have been thrown off from each cell or unit. But, as we sometimes see half an anther or a small portion of a filament becoming petali-form, or parts or mere stripes of the calyx assuming the colour and texture of the corolla, it is probable that with petals the gemmules of each cell are not aggregated together into a compound gemmule, but are free and separate. Even in so simple a case as that of a perfect cell, with its protoplasmic contents, nucleus, nucleolus, and walls, we do not know whether or not its development depends on a compound gemmule derived from each part.[[54]]
Having now endeavoured to show that the several foregoing assumptions are to a certain extent supported by analogous facts, and having alluded to some of the most doubtful points, we will consider how far the hypothesis brings under a single point of view the various cases enumerated in the First Part. All the forms of reproduction graduate into one another and agree in their product; for it is impossible to distinguish between organisms produced from buds, from self-division, or from fertilised germs; such organisms are liable to variations of the same nature and to reversions of the same kind; and as, according to our hypothesis, all the forms of reproduction depend on the aggregation of gemmules derived from the whole body, we can understand this remarkable agreement. Parthenogenesis is no longer wonderful, and if we did not know that great good followed from the union of the sexual elements derived from two distinct individuals, the wonder would be that parthenogenesis did not occur much oftener than it does. On any ordinary theory of reproduction the formation of graft-hybrids, and the action of the male element on the tissues of the mother-plant, as well as on the future progeny of female animals, are great anomalies; but they are intelligible on our hypothesis. The reproductive organs do not actually create the sexual elements; they merely determine the aggregation and perhaps the multiplication of the gemmules in a special manner. These organs, however, together with their accessory parts, have high functions to perform. They adapt one or both elements for independent temporary existence, and for mutual union. The stigmatic secretion acts on the pollen of a plant of the same species in a wholly different manner to what it does on the pollen of one belonging to a distinct genus or family. The spermatophores of the Cephalopoda are wonderfully complex structures, which were formerly mistaken for parasitic worms; and the spermatozoa of some animals possess attributes which, if observed in an independent animal, would be put down to instinct guided by sense-organs,—as when the spermatozoa of an insect find their way into the minute micropyle of the egg.
The antagonism which has long been observed,[[55]] with certain exceptions, between growth and the power of sexual reproduction[[56]]—between the repair of injuries and gemmation—and with plants, between rapid increase by buds, rhizomes, etc., and the production of seed, is partly explained by the gemmules not existing in sufficient numbers for these processes to be carried on simultaneously.
Hardly any fact in physiology is more wonderful than the power of re-growth; for instance, that a snail should be able to reproduce its head, or a salamander its eyes, tail, and legs, exactly at the points where they have been cut off. Such cases are explained by the presence of gemmules derived from each part, and disseminated throughout the body. I have heard the process compared with that of the repair of the broken angles of a crystal by re-crystallisation; and the two processes have this much in common, that in the one case the polarity of the molecules is the efficient cause, and in the other the affinity of the gemmules for particular nascent cells. But we have here to encounter two objections which apply not only to the re-growth of a part, or of a bisected individual, but to fissiparous generation and budding. The first objection is that the part which is reproduced is in the same stage of development as that of the being which has been operated on or bisected; and in the case of buds, that the new beings thus produced are in the same stage as that of the budding parent. Thus a mature salamander, of which the tail has been cut off, does not reproduce a larval tail; and a crab does not reproduce a larval leg. In the case of budding it was shown in the first part of this chapter that the new being thus produced does not retrograde in development,—that is, does not pass through those earlier stages, which the fertilised germ has to pass through. Nevertheless, the organisms operated on or multiplying themselves by buds must, by our hypothesis, include innumerable gemmules derived from every part or unit of the earlier stages of development; and why do not such gemmules reproduce the amputated part or the whole body at a corresponding early stage of development?
The second objection, which has been insisted on by Delpino, is that the tissues, for instance, of a mature salamander or crab, of which a limb has been removed, are already differentiated and have passed through their whole course of development; and how can such tissues in accordance with our hypothesis attract and combine with the gemmules of the part which is to be reproduced? In answer to these two objections we must bear in mind the evidence which has been advanced, showing that at least in a large number of cases the power of re-growth is a localised faculty, acquired for the sake of repairing special injuries to which each particular creature is liable; and in the case of buds or fissiparous generation, for the sake of quickly multiplying the organism at a period of life when it can be supported in large numbers. These considerations lead us to believe that in all such cases a stock of nascent cells or of partially developed gemmules are retained for this special purpose either locally or throughout the body, ready to combine with the gemmules derived from the cells which come next in due succession. If this be admitted we have a sufficient answer to the above two objections. Anyhow, pangenesis seems to throw a considerable amount of light on the wonderful power of re-growth.
It follows, also, from the view just given, that the sexual elements differ from buds in not including nascent cells or gemmules in a somewhat advanced stage of development, so that only the gemmules belonging to the earliest stages are first developed. As young animals and those which stand low in the scale generally have a much greater capacity for re-growth than older and higher animals, it would also appear that they retain cells in a nascent state, or partially developed gemmules, more readily than do animals which have already passed through a long series of developmental changes. I may here add that although ovules can be detected in most or all female animals at an extremely early age, there is no reason to doubt that gemmules derived from parts modified during maturity can pass into the ovules.
With respect to hybridism, pangenesis agrees well with most of the ascertained facts. We must believe, as previously shown, that several gemmules are requisite for the development of each cell or unit. But from the occurrence of parthenogenesis, more especially from those cases in which an embryo is only partially formed, we may infer that the female element generally includes gemmules in nearly sufficient number for independent development, so that when united with the male element the gemmules are superabundant. Now, when two species or races are crossed reciprocally, the offspring do not commonly differ, and this shows that the sexual elements agree in power, in accordance with the view that both include the same gemmules. Hybrids and mongrels are also generally intermediate in character between the two parent-forms, yet occasionally they closely resemble one parent in one part and the other parent in another part, or even in their whole structure: nor is this difficult to understand on the admission that the gemmules in the fertilised germ are superabundant in number, and that those derived from one parent may have some advantage in number, affinity, or vigour over those derived from the other parent. Crossed forms sometimes exhibit the colour or other characters of either parent in stripes or blotches; and this occurs in the first generation, or through reversion in succeeding bud and seminal generations, of which fact several instances were given in the eleventh chapter. In these cases we must follow Naudin[[57]] and admit that the “essence” or “element” of the two species,—terms which I should translate into the gemmules,—have an affinity for their own kind, and thus separate themselves into distinct stripes or blotches; and reasons were given, when discussing in the fifteenth chapter the incompatibility of certain characters to unite, for believing in such mutual affinity. When two forms are crossed, one is not rarely found to be prepotent in the transmission of its characters over the other; and this we can explain by again assuming that the one form has some advantage over the other in the number, vigour, or affinity of its gemmules. In some cases, however, certain characters are present in the one form and latent in the other; for instance, there is a latent tendency in all pigeons to become blue, and, when a blue pigeon is crossed with one of any other colour, the blue tint is generally prepotent. The explanation of this form of prepotency will be obvious when we come to the consideration of Reversion.
When two distinct species are crossed, it is notorious that they do not yield the full or proper number of offspring; and we can only say on this head that, as the development of each organism depends on such nicely-balanced affinities between a host of gemmules and nascent cells, we need not feel at all surprised that the commixture of gemmules derived from two distinct species should lead to partial or complete failure of development. With respect to the sterility of hybrids produced from the union of two distinct species, it was shown in the nineteenth chapter that this depends exclusively on the reproductive organs being specially affected; but why these organs should be thus affected we do not know, any more than why unnatural conditions of life, though compatible with health, should cause sterility; or why continued close interbreeding, or the illegitimate unions of heterostyled plants, induce the same result. The conclusion that the reproductive organs alone are affected, and not the whole organisation, agrees perfectly with the unimpaired or even increased capacity in hybrid plants for propagation by buds; for this implies, according to our hypothesis, that the cells of the hybrids throw off hybridised gemmules, which become aggregated into buds, but fail to become aggregated within the reproductive organs, so as to form the sexual elements. In a similar manner many plants, when placed under unnatural conditions, fail to produce seed, but can readily be propagated by buds. We shall presently see that pangenesis agrees well with the strong tendency to reversion exhibited by all crossed animals and plants.
Each organism reaches maturity through a longer or shorter course of growth and development: the former term being confined to mere increase of size, and development to changed structure. The changes may be small and insensibly slow, as when a child grows into a man, or many, abrupt, and slight, as in the metamorphoses of certain ephemerous insects, or, again, few and strongly-marked, as with most other insects. Each newly formed part may be moulded within a previously existing and corresponding part, and in this case it will appear, falsely as I believe, to be developed from the old part; or it may be formed within a distinct part of the body, as in the extreme cases of metagenesis. An eye, for instance, may be developed at a spot where no eye previously existed. We have also seen that allied organic beings in the course of their metamorphoses sometimes attain nearly the same structure after passing through widely different forms; or conversely, after passing through nearly the same early forms, arrive at widely different mature forms. In these cases it is very difficult to accept the common view that the first-formed cells or units possess the inherent power, independently of any external agency, of producing new structures wholly different in form, position, and function. But all these cases become plain on the hypothesis of pangenesis. The units, during each stage of development, throw off gemmules, which, multiplying, are transmitted to the offspring. In the offspring, as soon as any particular cell or unit becomes partially developed, it unites with (or, to speak metaphorically, is fertilised by) the gemmule of the next succeeding cell, and so onwards. But organisms have often been subjected to changed conditions of life at a certain stage of their development, and in consequence have been slightly modified; and the gemmules cast off from such modified parts will tend to reproduce parts modified in the same manner. This process may be repeated until the structure of the part becomes greatly changed at one particular stage of development, but this will not necessarily affect other parts, whether previously or subsequently formed. In this manner we can understand the remarkable independence of structure in the successive metamorphoses, and especially in the successive metageneses of many animals. In the case, however, of diseases which supervene during old age, subsequently to the ordinary period of procreation, and which, nevertheless, are sometimes inherited, as occurs with brain and heart complaints, we must suppose that the organs were affected at an early age and threw off at this period affected gemmules; but that the affection became visible or injurious only after the prolonged growth, in the strict sense of the word, of the part. In all the changes of structure which regularly supervene during old age, we probably see the effects of deteriorated growth, and not of true development.
The principle of the independent formation of each part, owing to the union of the proper gemmules with certain nascent cells, together with the superabundance of the gemmules derived from both parents, and the subsequent self-multiplication of the gemmules, throws light on a widely different group of facts, which on any ordinary view of development appears very strange. I allude to organs which are abnormally transposed or multiplied. For instance, a curious case has been recorded by Dr. Elliott Coues[[58]] of a monstrous chicken with a perfect additional right leg articulated to the left side of the pelvis. Gold-fish often have supernumerary fins placed on various parts of their bodies. When the tail of a lizard is broken off, a double tail is sometimes reproduced; and when the foot of the salamander was divided longitudinally by Bonnet, additional digits were occasionally formed. Valentin injured the caudal extremity of an embryo, and three days afterwards it produced rudiments of a double pelvis and of double hind-limbs.[[59]] When frogs, toads, etc., are born with their limbs doubled, as sometimes happens, the doubling, as Gervais remarks,[[60]] cannot be due to the complete fusion of two embryos, with the exception of the limbs, for the larvæ are limbless. The same argument is applicable[[61]] to certain insects produced with multiple legs or antennæ, for these are metamorphosed from apodal or antennæ-less larvæ. Alphonse Milne-Edwards[[62]] has described the curious case of a crustacean in which one eye-peduncle supported, instead of a complete eye, only an imperfect cornea, and out of the centre of this a portion of an antenna was developed. A case has been recorded[[63]] of a man who had during both dentitions a double tooth in place of the left second incisor, and he inherited this peculiarity from his paternal grandfather. Several cases are known[[64]] of additional teeth having been developed in the orbit of the eye, and, more especially with horses, in the palate. Hairs occasionally appear in strange situations, as “within the substance of the brain.”[[65]] Certain breeds of sheep bear a whole crowd of horns on their foreheads. As many as five spurs have been seen on both legs of certain Game-fowls. In the Polish fowl the male is ornamented with a topknot of hackles like those on his neck, whilst the female has a top-knot formed of common feathers. In feather-footed pigeons and fowls, feathers like those on the wing arise from the outer side of the legs and toes. Even the elemental parts of the same feather may be transposed; for in the Sebastopol goose, barbules are developed on the divided filaments of the shaft. Imperfect nails sometimes appear on the stumps of the amputated fingers of man[[66]] and it is an interesting fact that with the snake-like Saurians, which present a series with more and more imperfect limbs, the terminations of the phalanges first disappear, “the nails becoming transferred to their proximal remnants, or even to parts which are not phalanges.”[[67]]
Analogous cases are of such frequent occurrence with plants that they do not strike us with sufficient surprise. Supernumerary petals, stamens, and pistils, are often produced. I have seen a leaflet low down in the compound leaf of Vicia sativa replaced by a tendril; and a tendril possesses many peculiar properties, such as spontaneous movement and irritability. The calyx sometimes assumes, either wholly or by stripes, the colour and texture of the corolla. Stamens are so frequently converted into petals, more or less completely, that such cases are passed over as not deserving notice; but as petals have special functions to perform, namely, to protect the included organs, to attract insects, and in not a few cases to guide their entrance by well-adapted contrivances, we can hardly account for the conversion of stamens into petals merely by unnatural or superfluous nourishment. Again, the edge of a petal may occasionally be found including one of the highest products of the plant, namely, pollen; for instance, I have seen the pollen-mass of an Ophrys, which is a very complex structure, developed in the edge of an upper petal. The segments of the calyx of the common pea have been observed partially converted into carpels, including ovules, and with their tips converted into stigmas. Mr. Salter and Dr. Maxwell Masters have found pollen within the ovules of the passion-flower and of the rose. Buds may be developed in the most unnatural positions, as on the petal of a flower. Numerous analogous facts could be given.[[68]]
I do not know how physiologists look at such facts as the foregoing. According to the doctrine of pangenesis, the gemmules of the transposed organs become developed in the wrong place, from uniting with wrong cells or aggregates of cells during their nascent state; and this would follow from a slight modification in their elective affinities. Nor ought we to feel much surprise at the affinities of cells and gemmules varying, when we remember the many curious cases given in the seventeenth chapter, of plants which absolutely refuse to be fertilised by their own pollen, though abundantly fertile with that of any other individual of the same species, and in some cases only with that of a distinct species. It is manifest that the sexual elective affinities of such plants—to use the term employed by Gärtner—have been modified. As the cells of adjoining or homologous parts will have nearly the same nature, they will be particularly liable to acquire by variation each other’s elective affinities; and we can thus understand to a certain extent such cases as a crowd of horns on the heads of certain sheep, of several spurs on the legs of fowls, hackle-like feathers on the heads of the males of other fowls, and with the pigeon wing-like feathers on their legs and membrane between their toes, for the leg is the homologue of the wing. As all the organs of plants are homologous and spring from a common axis, it is natural that they should be eminently liable to transposition. It ought to be observed that when any compound part, such as an additional limb or an antenna, springs from a false position, it is only necessary that the few first gemmules should be wrongly attached; for these whilst developing would attract other gemmules in due succession, as in the re-growth of an amputated limb. When parts which are homologous and similar in structure, as the vertebræ of snakes or the stamens of polyandrous flowers, etc., are repeated many times in the same organism, closely allied gemmules must be extremely numerous, as well as the points to which they ought to become united; and, in accordance with the foregoing views, we can to a certain extent understand Isid. Geoffroy Saint-Hilaire’s law, that parts, which are already multiple, are extremely liable to vary in number.
Variability often depends, as I have attempted to show, on the reproductive organs being injuriously affected by changed conditions; and in this case the gemmules derived from the various parts of the body are probably aggregated in an irregular manner, some superfluous and others deficient. Whether a superabundance of gemmules would lead to the increased size of any part cannot be told; but we can see that their partial deficiency, without necessarily leading to the entire abortion of the part, might cause considerable modifications; for in the same manner as plants, if their own pollen be excluded, are easily hybridised, so, in the case of cells, if the properly succeeding gemmules were absent, they would probably combine easily with other and allied gemmules, as we have just seen with transposed parts.
In variations caused by the direct action of changed conditions, of which several instances have been given, certain parts of the body are directly affected by the new conditions, and consequently throw off modified gemmules, which are transmitted to the offspring. On any ordinary view it is unintelligible how changed conditions, whether acting on the embryo, the young or the adult, can cause inherited modifications. It is equally or even more unintelligible on any ordinary view, how the effects of the long-continued use or disuse of a part, or of changed habits of body or mind, can be inherited. A more perplexing problem can hardly be proposed; but on our view we have only to suppose that certain cells become at last structurally modified; and that these throw off similarly modified gemmules. This may occur at any period of development, and the modification will be inherited at a corresponding period; for the modified gemmules will unite in all ordinary cases with the proper preceding cells, and will consequently be developed at the same period at which the modification first arose. With respect to mental habits or instincts, we are so profoundly ignorant of the relation between the brain and the power of thought that we do not know positively whether a fixed habit induces any change in the nervous system, though this seems highly probable; but when such habit or other mental attribute, or insanity, is inherited, we must believe that some actual modification is transmitted;[[69]] and this implies, according to our hypothesis, that gemmules derived from modified nerve-cells are transmitted to the offspring.
It is generally necessary that an organism should be exposed during several generations to changed conditions or habits, in order that any modification thus acquired should appear in the offspring. This may be partly due to the changes not being at first marked enough to catch attention, but this explanation is insufficient; and I can account for the fact only by the assumption, which we shall see under the head of reversion is strongly supported, that gemmules derived from each unmodified unit or part are transmitted in large numbers to successive generations, and that the gemmules derived from the same unit after it has been modified go on multiplying under the same favourable conditions which first caused the modification, until at last they become sufficiently numerous to overpower and supplant the old gemmules.
A difficulty may be here noticed; we have seen that there is an important difference in the frequency, though not in the nature, of the variations in plants propagated by sexual and asexual generation. As far as variability depends on the imperfect action of the reproductive organs under changed conditions, we can at once see why plants propagated asexually should be far less variable than those propagated sexually. With respect to the direct action of changed conditions, we know that organisms produced from buds do not pass through the earlier phases of development; they will therefore not be exposed, at that period of life when structure is most readily modified, to the various causes inducing variability in the same manner as are embryos and young larval forms; but whether this is a sufficient explanation I know not.
With respect to variations due to reversion, there is a similar difference between plants propagated from buds and seeds. Many varieties can be propagated securely by buds, but generally or invariably revert to their parent-forms by seed. So, also, hybridised plants can be multiplied to any extent by buds, but are continually liable to reversion by seed,—that is, to the loss of their hybrid or intermediate character. I can offer no satisfactory explanation of these facts. Plants with variegated leaves, phloxes with striped flowers, barberries with seedless fruit, can all be securely propagated by buds taken from the stem or branches; but buds from the roots of these plants almost invariably lose their character and revert to their former condition. This latter fact is also inexplicable, unless buds developed from the roots are as distinct from those on the stem, as is one bud on the stem from another, and we know that these latter behave like independent organisms.
Finally, we see that on the hypothesis of pangenesis variability depends on at least two distinct groups of causes. Firstly, the deficiency, superabundance, and transposition of gemmules, and the redevelopment of those which have long been dormant; the gemmules themselves not having undergone any modification; and such changes will amply account for much fluctuating variability. Secondly, the direct action of changed conditions on the organisation, and of the increased use or disuse of parts; and in this case the gemmules from the modified units will be themselves modified, and, when sufficiently multiplied, will supplant the old gemmules and be developed into new structures.
Turning now to the laws of Inheritance. If we suppose a homogeneous gelatinous protozoon to vary and assume a reddish colour, a minute separated particle would naturally, as it grew to full size, retain the same colour; and we should have the simplest form of inheritance.[[70]] Precisely the same view may be extended to the infinitely numerous and diversified units of which the whole body of one of the higher animals is composed; the separated particles being our gemmules. We have already sufficiently discussed by implication, the important principle of inheritance at corresponding ages. Inheritance as limited by sex and by the season of the year (for instance with animals becoming white in winter) is intelligible if we may believe that the elective affinities of the units of the body are slightly different in the two sexes, especially at maturity, and in one or both sexes at different seasons, so that they unite with different gemmules. It should be remembered that, in the discussion on the abnormal transposition of organs, we have seen reason to believe that such elective affinities are readily modified. But I shall soon have to recur to sexual and seasonal inheritance. These several laws are therefore explicable to a large extent through pangenesis, and on no other hypothesis which has as yet been advanced.
But it appears at first sight a fatal objection to our hypothesis that a part or organ may be removed during several successive generations, and if the operation be not followed by disease, the lost part reappears in the offspring. Dogs and horses formerly had their tails docked during many generations without any inherited effect; although, as we have seen, there is some reason to believe that the tailless condition of certain sheep-dogs is due to such inheritance. Circumcision has been practised by the Jews from a remote period, and in most cases the effects of the operation are not visible in the offspring; though some maintain that an inherited effect does occasionally appear. If inheritance depends on the presence of disseminated gemmules derived from all the units of the body, why does not the amputation or mutilation of a part, especially if effected on both sexes, invariably affect the offspring? The answer in accordance with our hypothesis probably is that gemmules multiply and are transmitted during a long series of generations—as we see in the reappearance of zebrine stripes on the horse—in the reappearance of muscles and other structures in man which are proper to his lowly organised progenitors, and in many other such cases. Therefore the long-continued inheritance of a part which has been removed during many generations is no real anomaly, for gemmules formerly derived from the part are multiplied and transmitted from generation to generation.
We have as yet spoken only of the removal of parts, when not followed by morbid action: but when the operation is thus followed, it is certain that the deficiency is sometimes inherited. In a former chapter instances were given, as of a cow, the loss of whose horn was followed by suppuration, and her calves were destitute of a horn on the same side of their heads. But the evidence which admits of no doubt is that given by Brown-Séquard with respect to guinea-pigs, which after their sciatic nerves had been divided, gnawed off their own gangrenous toes, and the toes of their offspring were deficient in at least thirteen instances on the corresponding feet. The inheritance of the lost part in several of these cases is all the more remarkable as only one parent was affected; but we know that a congenital deficiency is often transmitted from one parent alone—for instance, the offspring of hornless cattle of either sex, when crossed with perfect animals, are often hornless. How, then, in accordance with our hypothesis can we account for mutilations being sometimes strongly inherited, if they are followed by diseased action? The answer probably is that all the gemmules of the mutilated or amputated part are gradually attracted to the diseased surface during the reparative process, and are there destroyed by the morbid action.
A few words must be added on the complete abortion of organs. When a part becomes diminished by disuse prolonged during many generations, the principle of economy of growth, together with intercrossing, will tend to reduce it still further as previously explained, but this will not account for the complete or almost complete obliteration of, for instance, a minute papilla of cellular tissue representing a pistil, or of a microscopically minute nodule of bone representing a tooth. In certain cases of suppression not yet completed, in which a rudiment occasionally reappears through reversion, dispersed gemmules derived from this part must, according to our view, still exist; we must therefore suppose that the cells, in union with which the rudiment was formerly developed, fail in their affinity for such gemmules, except in the occasional cases of reversion. But when the abortion is complete and final, the gemmules themselves no doubt perish; nor is this in any way improbable, for, though a vast number of active and long-dormant gemmules are nourished in each living creature, yet there must be some limit to their number; and it appears natural that gemmules derived from reduced and useless parts would be more liable to perish than those freshly derived from other parts which are still in full functional activity.
The last subject that need be discussed, namely, Reversion, rests on the principle that transmission and development, though generally acting in conjunction, are distinct powers; and the transmission of gemmules with their subsequent development shows us how this is possible. We plainly see the distinction in the many cases in which a grandfather transmits to his grandson, through his daughter, characters which she does not, or cannot, possess. But before proceeding, it will be advisable to say a few words about latent or dormant characters. Most, or perhaps all, of the secondary characters, which appertain to one sex, lie dormant in the other sex; that is, gemmules capable of development into the secondary male sexual characters are included within the female; and conversely female characters in the male: we have evidence of this in certain masculine characters, both corporeal and mental, appearing in the female, when her ovaria are diseased or when they fail to act from old age. In like manner female characters appear in castrated males, as in the shape of the horns of the ox, and in the absence of horns in castrated stags. Even a slight change in the conditions of life due to confinement sometimes suffices to prevent the development of masculine characters in male animals, although their reproductive organs are not permanently injured. In the many cases in which masculine characters are periodically renewed, these are latent at other seasons; inheritance as limited by sex and season being here combined. Again, masculine characters generally lie dormant in male animals until they arrive at the proper age for reproduction. The curious case formerly given of a Hen which assumed the masculine characters, not of her own breed but of a remote progenitor, illustrates the close connection between latent sexual characters and ordinary reversion.
With those animals and plants which habitually produce several forms, as with certain butterflies described by Mr. Wallace, in which three female forms and one male form co-exist, or, as with the trimorphic species of Lythrum and Oxalis, gemmules capable of reproducing these different forms must be latent in each individual.
Insects are occasionally produced with one side or one quarter of their bodies like that of the male, with the other half or three-quarters like that of the female. In such cases the two sides are sometimes wonderfully different in structure, and are separated from each other by a sharp line. As gemmules derived from every part are present in each individual of both sexes, it must be the elective affinities of the nascent cells which in these cases differ abnormally on the two sides of the body. Almost the same principle comes into play with those animals, for instance, certain gasteropods and Verruca amongst cirripedes, which normally have the two sides of the body constructed on a very different plan; and yet a nearly equal number of individuals have either side modified in the same remarkable manner.
Reversion, in the ordinary sense of the word, acts so incessantly, that it evidently forms an essential part of the general law of inheritance. It occurs with beings, however propagated, whether by buds or seminal generation, and sometimes may be observed with advancing age even in the same individual. The tendency to reversion is often induced by a change of conditions, and in the plainest manner by crossing. Crossed forms of the first generation are generally nearly intermediate in character between their two parents; but in the next generation the offspring commonly revert to one or both of their grandparents, and occasionally to more remote ancestors. How can we account for these facts? Each unit in a hybrid must throw off, according to the doctrine of pangenesis, an abundance of hybridised gemmules, for crossed plants can be readily and largely propagated by buds; but by the same hypothesis dormant gemmules derived from both pure parent-forms are likewise present; and as these gemmules retain their normal condition, they would, it is probable, be enabled to multiply largely during the lifetime of each hybrid. Consequently the sexual elements of a hybrid will include both pure and hybridised gemmules; and when two hybrids pair, the combination of pure gemmules derived from the one hybrid with the pure gemmules of the same parts derived from the other, would necessarily lead to complete reversion of character; and it is, perhaps, not too bold a supposition that unmodified and undeteriorated gemmules of the same nature would be especially apt to combine. Pure gemmules in combination with hybridised gemmules would lead to partial reversion. And lastly, hybridised gemmules derived from both parent-hybrids would simply reproduce the original hybrid form.[[71]] All these cases and degrees of reversion incessantly occur.
It was shown in the fifteenth chapter that certain characters are antagonistic to each other or do not readily blend; hence, when two animals with antagonistic characters are crossed, it might well happen that a sufficiency of gemmules in the male alone for the reproduction of his peculiar characters, and in the female alone for the reproduction of her peculiar characters, would not be present; and in this case dormant gemmules derived from the same part in some remote progenitor might easily gain the ascendancy, and cause the reappearance of the long-lost character. For instance, when black and white pigeons, or black and white fowls, are crossed,—colours which do not readily blend,—blue plumage in the one case, evidently derived from the rock-pigeon, and red plumage in the other case, derived from the wild jungle-cock, occasionally reappear. With uncrossed breeds the same result follows, under conditions which favour the multiplication and development of certain dormant gemmules, as when animals become feral and revert to their pristine character. A certain number of gemmules being requisite for the development of each character, as is known to be the case from several spermatozoa or pollen-grains being necessary for fertilisation, and time favouring their multiplication, will perhaps account for the curious cases, insisted on by Mr. Sedgwick, of certain diseases which regularly appear in alternate generations. This likewise holds good, more or less strictly, with other weakly inherited modifications. Hence, as I have heard it remarked, certain diseases appear to gain strength by the intermission of a generation. The transmission of dormant gemmules during many successive generations is hardly in itself more improbable, as previously remarked, than the retention during many ages of rudimentary organs, or even only of a tendency to the production of a rudiment; but there is no reason to suppose that dormant gemmules can be transmitted and propagated for ever. Excessively minute and numerous as they are believed to be, an infinite number derived, during a long course of modification and descent, from each unit of each progenitor, could not be supported or nourished by the organism. But it does not seem improbable that certain gemmules, under favourable conditions, should be retained and go on multiplying for a much longer period than others. Finally, on the view here given, we certainly gain some insight into the wonderful fact that the child may depart from the type of both its parents, and resemble its grandparents, or ancestors removed by many hundreds of generations.
Conclusion.
The hypothesis of Pangenesis, as applied to the several great classes of facts just discussed, no doubt is extremely complex, but so are the facts. The chief assumption is that all the units of the body, besides having the universally admitted power of growing by self-division, throw off minute gemmules which are dispersed through the system. Nor can this assumption be considered as too bold, for we know from the cases of graft-hybridisation that formative matter of some kind is present in the tissues of plants, which is capable of combining with that included in another individual, and of reproducing every unit of the whole organism. But we have further to assume that the gemmules grow, multiply, and aggregate themselves into buds and the sexual elements; their development depending on their union with other nascent cells or units. They are also believed to be capable of transmission in a dormant state, like seeds in the ground, to successive generations.
In a highly-organised animal, the gemmules thrown off from each different unit throughout the body must be inconceivably numerous and minute. Each unit of each part, as it changes during development, and we know that some insects undergo at least twenty metamorphoses, must throw off its gemmules. But the same cells may long continue to increase by self-division, and even become modified by absorbing peculiar nutriment, without necessarily throwing off modified gemmules. All organic beings, moreover, include many dormant gemmules derived from their grandparents and more remote progenitors, but not from all their progenitors. These almost infinitely numerous and minute gemmules are contained within each bud, ovule, spermatozoon, and pollen-grain. Such an admission will be declared impossible; but number and size are only relative difficulties. Independent organisms exist which are barely visible under the highest powers of the microscope, and their germs must be excessively minute. Particles of infectious matter, so small as to be wafted by the wind or to adhere to smooth paper, will multiply so rapidly as to infect within a short time the whole body of a large animal. We should also reflect on the admitted number and minuteness of the molecules composing a particle of ordinary matter. The difficulty, therefore, which at first appears insurmountable, of believing in the existence of gemmules so numerous and small as they must be according to our hypothesis, has no great weight.
The units of the body are generally admitted by physiologists to be autonomous. I go one step further and assume that they throw off reproductive gemmules. Thus an organism does not generate its kind as a whole, but each separate unit generates its kind. It has often been said by naturalists that each cell of a plant has the potential capacity of reproducing the whole plant; but it has this power only in virtue of containing gemmules derived from every part. When a cell or unit is from some cause modified, the gemmules derived from it will be in like manner modified. If our hypothesis be provisionally accepted, we must look at all the forms of asexual reproduction, whether occurring at maturity or during youth, as fundamentally the same, and dependent on the mutual aggregation and multiplication of the gemmules. The re-growth of an amputated limb and the healing of a wound is the same process partially carried out. Buds apparently include nascent cells, belonging to that stage of development at which the budding occurs, and these cells are ready to unite with the gemmules derived from the next succeeding cells. The sexual elements, on the other hand, do not include such nascent cells; and the male and female elements taken separately do not contain a sufficient number of gemmules for independent development, except in the cases of parthenogenesis. The development of each being, including all the forms of metamorphosis and metagenesis, depends on the presence of gemmules thrown off at each period of life, and on their development, at a corresponding period, in union with preceding cells. Such cells may be said to be fertilised by the gemmules which come next in due order of development. Thus the act of ordinary impregnation and the development of each part in each being are closely analogous processes. The child, strictly speaking, does not grow into the man, but includes germs which slowly and successively become developed and form the man. In the child, as well as in the adult, each part generates the same part. Inheritance must be looked at as merely a form of growth, like the self-division of a lowly-organised unicellular organism. Reversion depends on the transmission from the forefather to his descendants of dormant gemmules, which occasionally become developed under certain known or unknown conditions. Each animal and plant may be compared with a bed of soil full of seeds, some of which soon germinate, some lie dormant for a period, whilst others perish. When we hear it said that a man carries in his constitution the seeds of an inherited disease, there is much truth in the expression. No other attempt, as far as I am aware, has been made, imperfect as this confessedly is, to connect under one point of view these several grand classes of facts. An organic being is a microcosm—a little universe, formed of a host of self-propagating organisms, inconceivably minute and numerous as the stars in heaven.
REFERENCES
[1] This hypothesis has been severely criticised by many writers, and it will be fair to give references to the more important articles. The best essay which I have seen is by Prof. Delpino, entitled ‘Sulla Darwiniana Teoria della Pangenesi, 1869,’ of which a translation appeared in ‘Scientific Opinion,’ Sept. 29th, 1869, and the succeeding numbers. He rejects the hypothesis, but criticises it fairly, and I have found his criticisms very useful. Mr. Mivart (‘Genesis of Species,’ 1871, chap. x.) follows Delpino, but adds no new objections of any weight. Dr. Bastian (‘The Beginnings of Life,’ 1872, vol. ii. p. 98) says that the hypothesis “looks like a relic of the old rather than a fitting appanage of the new evolution philosophy.” He shows that I ought not to have used the term “pangenesis,” as it had been previously used by Dr. Gros in another sense. Dr. Lionel Beale (‘Nature,’ May 11th, 1871, p. 26) sneers at the whole doctrine with much acerbity and some justice. Prof. Wigand (‘Schriften der Gesell. der gesammt. Naturwissen. zu Marburg,’ B. ix. 1870) considers the hypothesis as unscientific and worthless. Mr. G. H. Lewes (‘Fortnightly Review,’ Nov. 1st, 1868, p. 503) seems to consider that it may be useful: he makes many good criticisms in a perfectly fair spirit. Mr. F. Galton, after describing his valuable experiments (‘Proc. Royal Soc.,’ vol. xix. p. 393) on the intertransfusion of the blood of distinct varieties of the rabbit, concludes by saying that in his opinion the results negative beyond all doubt the doctrine of Pangenesis. He informs me that subsequently to the publication of his paper he continued his experiments on a still larger scale for two more generations, without any sign of mongrelism showing itself in the very numerous offspring. I certainly should have expected that gemmules would have been present in the blood, but this is no necessary part of the hypothesis, which manifestly applies to plants and the lowest animals. Mr. Galton, in a letter to ‘Nature’ (April 27th, 1871, p. 502), also criticises various incorrect expressions used by me. On the other hand, several writers have spoken favourably of the hypothesis, but there would be no use in giving references to their articles. I may, however, refer to Dr. Ross’ work, ‘The Graft Theory of Disease; being an application of Mr. Darwin’s hypothesis of Pangenesis,’ 1872, as he gives several original and ingenious discussions.
[2] Quoted by Paget, ‘Lectures on Pathology,’ 1853, p. 159.
[3] Dr. Lachmann, also, observes (‘Annals and Mag. of Nat. History,’ 2nd series, vol. xix. 1857, p. 231) with respect to infusoria, that “fissation and gemmation pass into each other almost imperceptibly.” Again, Mr. W. C. Minor (‘Annals and Mag. of Nat. Hist.,’ 3rd series, vol. xi. p. 328) shows that with Annelids the distinction that has been made between fission and budding is not a fundamental one. See also Professor Clark’s work ‘Mind in Nature,’ New York, 1865, pp. 62, 94.
[4] See Bonnet, ‘Œuvres d’Hist. Nat.,’ tom. v., 1781, p. 339, for remarks on the budding-out of the amputated limbs of Salamanders.
[5] Paget, ‘Lectures on Pathology,’ 1853, p. 158.
[6] Ibid., pp. 152, 164.
[7] Translated in ‘Annals and Mag. of Nat. Hist.,’ April 1870, p. 272.
[8] Bischoff, as quoted by von Siebold, “Ueber Parthenogenesis,” ‘Sitzung der math. phys. Classe.’ Munich, Nov. 4th, 1871, p. 240. See also Quatrefages, ‘Annales des Sc. Nat. Zoolog.,’ 3rd series, 1850, p. 138.
[9] ‘On the Asexual Reproduction of Cecidomyide Larvæ,’ translated in ‘Annals and Mag. of Nat. Hist.,’ March 1866, pp. 167, 171.
[10] Prof. Allman speaks (‘Transact. R. Soc. of Edinburgh,’ vol. xxvi., 1870, p. 102) decisively on this head with respect to the Hydroida: he says, “It is a universal law in the succession of zooids, that no retrogression ever takes place in the series.”
[11] ‘Annals and Mag. of Nat. Hist.,’ 2nd series, vol. xx., 1857, pp. 153-455.
[12] ‘Annales des Sc. Nat.,’ 3rd series, 1850, tom. xiii.
[13] ‘Transact. Phil. Soc.,’ 1851, pp. 196, 208, 210; 1853 pp. 245, 247.
[14] ‘Beitrage zur Kenntniss,’ etc., 1844, s. 345.
[15] ‘Nouvelles Archives du Muséum,’ tom. i. p. 27.
[16] As quoted by Sir J. Lubbock in ‘Nat. Hist. Review,’ 1862, p. 345. Weijenbergh also raised (‘Nature,’ Dec. 21st, 1871, p. 149) two successive generations from unimpregnated females of another lepidopterous insect, Liparis dispar. These females did not produce at most one-twentieth of their full complement of eggs, and many of the eggs were worthless. Moreover the caterpillars raised from these unfertilised eggs “possessed far less vitality” than those from fertilised eggs. In the third parthenogenetic generation not a single egg yielded a caterpillar.
[17] ‘Entwickelungsgeschichte der Siphonophora,’ 1869, p. 73.
[18] Spallanzani, ‘An Essay on Animal Reproduction,’ translated by Dr. Maty, 1769, p. 79. Bonnet, ‘Œuvres d’Hist. Nat.,’ tom. v., part i., 4to. edit., 1781, pp. 343, 350.
[19] Vulpian, as quoted by Prof. Faivre, ‘La Variabilité des Espèces,’ 1868, p. 112.
[20] Dr. P. Hoy, ‘The American Naturalist,’ Sept. 1871, p. 579.
[21] Dr. Gunther, in Owen’s ‘Anatomy of Vertebrates,’ vol. i., 1866, p. 567. Spallanzani has made similar observations.
[22] A thrush was exhibited before the British Association at Hull in 1853 which had lost its tarsus, and this member, it was asserted, had been thrice reproduced; having been lost, I presume, each time by disease. Sir J. Paget informs me that he feels some doubt about the facts recorded by Sir J. Simpson (‘Monthly Journal of Medical Science,’ Edinburgh, 1848, new series, vol. ii., p. 890) of the re-growth of limbs in the womb in the case of man.
[23] ‘Atti della Soc. Ital. di Sc. Nat.,’ vol. xi., 1869, p. 493.
[24] Lessona states that this is so in the paper just referred to. See also ‘The American Naturalist,’ Sept. 1871, p. 579.
[25] ‘Comptes Rendus,’ Oct. 1st, 1866, and June, 1867.
[26] Bonnet, ‘Oeuvres Hist. Nat.,’ vol. v., p. 294, as quoted by Prof. Rolleston in his remarkable address to the 36th annual meeting of the British Medical Association.
[27] ‘Proc. Boston Soc. of Nat. Hist.,’ vol. xii., 1868-69, p. 1.
[28] ‘Transact. Linn. Soc.,’ vol. xxiv., 1863, p. 62.
[29] ‘Parthenogenesis,’ 1849, pp. 25, 26. Prof. Huxley has some excellent remarks (‘Medical Times,’ 1856, p. 637) on this subject in reference to the development of star-fishes, and shows how curiously metamorphosis graduates into gemmation or zoid-formation, which is in fact the same as metagenesis.
[30] Prof. J. Reay Greene, in Günther’s ‘Record of Zoolog. Lit.,’ 1865, p. 625.
[31] Fritz Müller, ‘Für Darwin,’ 1864, s. 65, 71. The highest authority on crustaceans, Prof. Milne-Edwards, insists (‘Annal. des Sci. Nat.,’ 2nd series, Zoolog., tom. iii., p. 322) on the difference in the metamorphosis of closely-allied genera.
[32] Prof. Allman, in ‘Annals and Mag. of Nat. Hist.,’ 3rd series, vol. xiii., 1864, p. 348; Dr. S. Wright, ibid., vol. viii., 1861, p. 127. See also p. 358 for analogous statements by Sars.
[33] ‘Tissus Vivants,’ 1866, p. 22.
[34] ‘Cellular Pathology,’ translated by Dr. Chance, 1860, pp. 14, 18, 83, 460.
[35] Paget, ‘Surgical Pathology,’ vol. i., 1853, pp. 12-14.
[36] Ibid., p. 19.
[37] See Prof. Mantegazza’s interesting work, ‘Degli innesti Animali,’ etc., Milano, 1865, p. 51, tab. 3.
[38] ‘De la Production Artificielle des Os,’ p. 8.
[39] Isidore Geoffroy Saint-Hilaire, ‘Hist. des Anomalies,’ tom. ii., pp. 549, 560, 562; Virchow, ibid., p. 484. Lawson Tait, ‘The Pathology of Diseases of the Ovaries,’ 1874, pp. 61, 62.
[40] For the most recent classification of cells, see Ernst Hackel, ‘Generelle Morpholog.,’ B. ii., 1866, s. 275.
[41] Dr. W. Turner, ‘The Present Aspect of Cellular Pathology,’ ‘Edinburgh Medical Journal,’ April 1863.
[42] Mr. G. H. Lewes (‘Fortnightly Review,’ Nov. 1st, 1868, p. 506) remarks on the number of writers who have advanced nearly similar views. More than two thousand years ago Aristotle combated a view of this kind, which, as I hear from Dr. W. Ogle, was held by Hippocrates and others. Ray, in his ‘Wisdom of God’ (2nd edit., 1692, p. 68), says that “every part of the body seems to club and contribute to the seed.” The “organic molecules” of Buffon (‘Hist. Nat. Gen.,’ edit. of 1749, tom. ii., pp. 54, 62, 329, 333, 420, 425) appear at first sight to be the same as the gemmules of my hypothesis, but they are essentially different. Bonnet (‘Œuvres d’Hist. Nat.,’ tom. v., part i., 1781, 4to edit., p. 334) speaks of the limbs having germs adapted for the reparation of all possible losses; but whether these germs are supposed to be the same with those within buds and the sexual organs is not clear. Prof. Owen says (‘Anatomy of Vertebrates,’ vol. iii., 1868, p. 813) that he fails to see any fundamental difference between the views which he propounded in his ‘Parthenogenesis’ (1849, pp. 5-8), and which he now considers as erroneous, and my hypothesis of pangenesis: but a reviewer (‘Journal of Anat. and Phys.,’ May 1869, p. 441) shows how different they really are. I formerly thought that the “physiological units” of Herbert Spencer (‘Principles of Biology,’ vol. i., chaps. iv. and viii., 1863-64) were the same as my gemmules, but I now know that this is not the case. Lastly, it appears from a review of the present work by Prof. Mantegazza (‘Nuova Antologia, Maggio,’ 1868), that he (in his ‘Elementi di Igiene,’ Ediz. iii., p. 540) clearly foresaw the doctrine of pangenesis.
[43] Mr. Lowne has observed (‘Journal of Queckett Microscopical Club,’ Sept. 23rd, 1870) certain remarkable changes in the tissues of the larva of a fly, which makes him believe “it possible that organs and organisms are sometimes developed by the aggregation of excessively minute gemmules, such as those which Mr. Darwin’s hypothesis demands.”
[44] ‘Annales des Sc. Nat.,’ 3rd series, Bot., tom. xiv., 1850, p. 244.
[45] ‘Disease Germs,’ p. 20.
[46] See some very interesting papers on this subject by Dr. Beale, in ‘Medical Times and Gazette,’ Sept. 9th, 1865, pp. 273, 330.
[47] Third Report of the R. Comm. on the Cattle Plague, as quoted in ‘Gardener’s Chronicle,’ 1866, p. 446.
[48] Mr. F. Buckland found 6,867,840 eggs in a cod-fish (‘Land and Water,’ 1868, p. 62). An Ascaris produces about 64,000,000 eggs (Carpenter’s ‘Comp. Phys.,’ 1854, p. 590). Mr. J. Scott, of the Royal Botanic Garden of Edinburgh, calculated, in the same manner as I have done for some British Orchids (‘Fertilisation of Orchids,’ p. 344), the number of seeds in a capsule of an Acropera and found the number to be 371,250. Now this plant produces several flowers on a raceme, and many racemes during a season. In an allied genus, Gongora, Mr. Scott has seen twenty capsules produced on a single raceme; ten such racemes on the Acropera would yield above seventy-four millions of seed.
[49] Paget, ‘Lectures on Pathology,’ p. 27; Virchow, ‘Cellular Pathology,’ translated by Dr. Chance, pp. 123, 126, 294. Claude Bernard, ‘Des Tissus Vivants,’ pp. 177, 210, 337; Müller, ‘Physiology,’ Eng. translat., p. 290.
[50] Prof. Ray Lankester has discussed several of the points here referred to as bearing on pangenesis, in his interesting essay, ‘On Comparative Longevity in Man and the Lower Animals,’ 1870, pp. 33, 77, etc.
[51] Dr. Ross refers to this subject in his ‘Graft Theory of Disease,’ 1872, p. 53.
[52] Virchow, ‘Cellular Pathology,’ translated by Dr. Chance, 1860, pp. 60, 162, 245, 441, 454.
[53] Ibid., pp. 412-426.
[54] See some good criticisms on this head by Delpino and by Mr. G. H. Lewes in the ‘Fortnightly Review,’ Nov. 1st, 1868, p. 509.
[55] Mr. Herbert Spencer (‘Principles of Biology,’ vol. ii., p. 430) has fully discussed this antagonism.
[56] The male salmon is known to breed at a very early age. The Triton and Siredon, whilst retaining their larval branchiæ, according to Filippi and Duméril (‘Annals and Mag. of Nat. Hist.,’ 3rd series, 1866, p. 157) are capable of reproduction. Ernst Haeckel has recently (‘Monatsbericht Akad. Wiss. Berlin,’ Feb. 2nd, 1865) observed the surprising case of a medusa, with its reproductive organs active, which produces by budding a widely different form of medusa; and this latter also has the power of sexual reproduction. Krohn has shown (‘Annals and Mag. of Nat. Hist.,’ 3rd series, vol. xix., 1862, p. 6) that certain other medusæ, whilst sexually mature, propagate by gemmæ. See also Kolliker, ‘Morphologie und Entwickelungsgeschichte des Pennatulidenstammes,’ 1872, p. 12.
[57] See his excellent discussion on this subject in ‘Nouvelles Archives du Museum,’ tom. i., p. 151.
[58] ‘Proc. Boston Soc. of Nat. Hist.,’ republished in ‘Scientific Opinion,’ Nov. 10th, 1869, p. 488.
[59] Todd’s ‘Cyclop. of Anat. and Phys.,’ vol. iv., 1849-52, p. 975.
[60] ‘Compte Rendus,’ Nov. 14th, 1865, p. 800.
[61] As previously remarked by Quatrefages, in his ‘Métamorphoses de l’Homme,’ etc., 1862, p. 129.
[62] Günther’s ‘Zoological Record,’ 1864, p. 279.
[63] Sedgwick, ‘Medico-Chirurg. Review,’ April 1863, p. 454.
[64] Isid. Geoffroy Saint-Hilaire, ‘Hist. des Anomalies,’ tom. i., 1832, pp. 435, 657; and tom. ii., p. 560.
[65] Virchow, ‘Cellular Pathology,’ 1860, p. 66.
[66] Müller’s ‘Phys.,’ Eng. Translat., vol. i., 1833, p. 407. A case of this kind has lately been communicated to me.
[67] Dr. Fürbringer, ‘Die Knochen etc. bei den schlangenähnlichen Sauriern,’ as reviewed in ‘Journal of Anat. and Phys.,’ May 1870, p. 286.
[68] Moquin-Tandon, ‘Tératologie Vég.,’ 1841, pp. 218, 220, 353. For the case of the pea, see ‘Gardener’s Chronicle,’ 1866, p. 897. With respect to pollen within ovules, see Dr. Masters in ‘Science Review,’ Oct. 1873, p. 369. The Rev. J. M. Berkeley describes a bud developed on a petal of a Clarkia, in ‘Gardener’s Chronicle,’ April 28th, 1866.
[69] See some remarks to this effect by Sir H. Holland in his ‘Medical Notes,’ 1839, p. 32.
[70] This is the view taken by Prof. Haeckel, in his ‘Generelle Morphologie’ (B. ii. s. 171), who says: “Lediglich die partielle Identität der specifisch constituirten Materie im elterlichen und im kindlichen Organismus, die Theilung dieser Materie bei der Fortpflanzung, ist die Ursache der Erblichkeit.”
[71] In these remarks I, in fact, follow Naudin, who speaks of the elements or essences of the two species which are crossed. See his excellent memoir in the ‘Nouvelles Archives du Muséum,’ tom. i., p. 151.
CHAPTER XXVIII.
CONCLUDING REMARKS.
DOMESTICATION—NATURE AND CAUSES OF VARIABILITY—SELECTION—DIVERGENCE AND DISTINCTNESS OF CHARACTER—EXTINCTION OF RACES—CIRCUMSTANCES FAVOURABLE TO SELECTION BY MAN—ANTIQUITY OF CERTAIN RACES—THE QUESTION WHETHER EACH PARTICULAR VARIATION HAS BEEN SPECIALLY PREORDAINED.
As summaries have been added to nearly all the chapters, and as, in the chapter on pangenesis, various subjects, such as the forms of reproduction, inheritance, reversion, the causes and laws of variability, etc., have been recently discussed, I will here only make a few general remarks on the more important conclusions which may be deduced from the multifarious details given throughout this work.
Savages in all parts of the world easily succeed in taming wild animals; and those inhabiting any country or island, when first visited by man, would probably have been still more easily tamed. Complete subjugation generally depends on an animal being social in its habits, and on receiving man as the chief of the herd or family. In order that an animal should be domesticated it must be fertile under changed conditions of life, and this is far from being always the case. An animal would not have been worth the labour of domestication, at least during early times, unless of service to man. From these circumstances the number of domesticated animals has never been large. With respect to plants, I have shown in the ninth chapter how their varied uses were probably first discovered, and the early steps in their cultivation. Man could not have known, when he first domesticated an animal or plant, whether it would flourish and multiply when transported to other countries, therefore he could not have been thus influenced in his choice. We see that the close adaptation of the reindeer and camel to extremely cold and hot countries has not prevented their domestication. Still less could man have foreseen whether his animals and plants would vary in succeeding generations and thus give birth to new races; and the small capacity of variability in the goose has not prevented its domestication from a remote epoch.
With extremely few exceptions, all animals and plants which have been long domesticated have varied greatly. It matters not under what climate, or for what purpose they are kept, whether as food for man or beast, for draught or hunting, for clothing or mere pleasure,—under all these circumstances races have been produced which differ more from one another than do the forms which in a state of nature are ranked as different species. Why certain animals and plants have varied more under domestication than others we do not know, any more than why some are rendered more sterile than others under changed conditions of life. But we have to judge of the amount of variation which our domestic productions have undergone, chiefly by the number and amount of difference between the races which have been formed, and we can often clearly see why many and distinct races have not been formed, namely, because slight successive variations have not been steadily accumulated; and such variations will never be accumulated if an animal or plant be not closely observed, much valued, and kept in large numbers.
The fluctuating, and, as far as we can judge, never-ending variability of our domesticated productions,—the plasticity of almost their whole organisation,--is one of the most important lessons which we learn from the numerous details given in the earlier chapters of this work. Yet domesticated animals and plants can hardly have been exposed to greater changes in their conditions of life than have many natural species during the incessant geological, geographical, and climatal changes to which the world has been subject; but domesticated productions will often have been exposed to more sudden changes and to less continuously uniform conditions. As man has domesticated so many animals and plants belonging to widely different classes, and as he certainly did not choose with prophetic instinct those species which would vary most, we may infer that all natural species, if exposed to analogous conditions, would, on an average, vary to the same degree. Few men at the present day will maintain that animals and plants were created with a tendency to vary, which long remained dormant, in order that fanciers in after ages might rear, for instance, curious breeds of the fowl, pigeon, or canary-bird.
From several causes it is difficult to judge of the amount of modification which our domestic productions have undergone. In some cases the primitive parent-stock has become extinct; or it cannot be recognised with certainty, owing to its supposed descendants having been so much modified. In other cases two or more closely-allied forms, after being domesticated, have crossed; and then it is difficult to estimate how much of the character of the present descendants ought to be attributed to variation, and how much to the influence of the several parent-stocks. But the degree to which our domesticated breeds have been modified by the crossing of distinct species has probably been much exaggerated by some authors. A few individuals of one form would seldom permanently affect another form existing in greater numbers; for, without careful selection, the stain of the foreign blood would soon be obliterated, and during early and barbarous times, when our animals were first domesticated, such care would seldom have been taken.
There is good reason to believe in the case of the dog, ox, pig, and of some other animals, that several of our races are descended from distinct wild prototypes; nevertheless the belief in the multiple origin of our domesticated animals has been extended by some few naturalists and by many breeders to an unauthorised extent. Breeders refuse to look at the whole subject under a single point of view; I have heard it said by a man, who maintained that our fowls were descended from at least half-a-dozen aboriginal species, that the evidence of the common origin of pigeons, ducks and rabbits, was of no avail with respect to fowls. Breeders overlook the improbability of many species having been domesticated at an early and barbarous period. They do not consider the improbability of species having existed in a state of nature which, if they resembled our present domestic breeds, would have been highly abnormal in comparison with all their congeners. They maintain that certain species, which formerly existed, have become extinct, or are now unknown, although formerly known. The assumption of so much recent extinction is no difficulty in their eyes; for they do not judge of its probability by the facility or difficulty of the extinction of other closely-allied wild forms. Lastly, they often ignore the whole subject of geographical distribution as completely as if it were the result of chance.
Although from the reasons just assigned it is often difficult to judge accurately of the amount of change which our domesticated productions have undergone, yet this can be ascertained in the cases in which all the breeds are known to be descended from a single species,—as with the pigeon, duck, rabbit, and almost certainly with the fowl; and by the aid of analogy this can be judged of to a certain extent with domesticated animals descended from several wild stocks. It is impossible to read the details given in the earlier chapters and in many published works, or to visit our various exhibitions, without being deeply impressed with the extreme variability of our domesticated animals and cultivated plants. No part of the organisation escapes the tendency to vary. The variations generally affect parts of small vital or physiological importance, but so it is with the differences which exist between closely-allied species. In these unimportant characters there is often a greater difference between the breeds of the same species than between the natural species of the same genus, as Isidore Geoffroy has shown to be the case with size, and as is often the case with the colour, texture, form, etc., of the hair, feathers, horns, and other dermal appendages.
It has often been asserted that important parts never vary under domestication, but this is a complete error. Look at the skull of the pig in any one of the highly improved breeds, with the occipital condyles and other parts greatly modified; or look at that of the niata ox. Or, again, in the several breeds of the rabbit, observe the elongated skull, with the differently shaped occipital foramen, atlas, and other cervical vertebrae. The whole shape of the brain, together with the skull, has been modified in Polish fowls; in other breeds of the fowl the number of the vertebrae and the forms of the cervical vertebrae have been changed. In certain pigeons the shape of the lower jaw, the relative length of the tongue, the size of the nostrils and eyelids, the number and shape of the ribs, the form and size of the oesophagus, have all varied. In certain quadrupeds the length of the intestines has been much increased or diminished. With plants we see wonderful differences in the stones of various fruits. In the Cucurbitaceae several highly important characters have varied, such as the sessile position of the stigmas on the ovarium, the position of the carpels, and the projection of the ovarium out of the receptacle. But it would be useless to run through the many facts given in the earlier chapters.
It is notorious how greatly the mental disposition, tastes, habits, consensual movements, loquacity or silence, and tone of voice have varied and been inherited in our domesticated animals. The dog offers the most striking instance of changed mental attributes, and these differences cannot be accounted for by descent from distinct wild types.
New characters may appear and old ones disappear at any stage of development, being inherited at a corresponding stage. We see this in the difference between the eggs, the down on the chickens and the first plumage of the various breeds of the fowl; and still more plainly in the differences between the caterpillars and cocoons of the various breeds of the silk-moth. These facts, simple as they appear, throw light on the differences between the larval and adult states of allied natural species, and on the whole great subject of embryology. New characters first appearing late in life are apt to become attached exclusively to that sex in which they first arose, or they may be developed in a much higher degree in this than in the other sex; or again, after having become attached to one sex, they may be transferred to the opposite sex. These facts, and more especially the circumstance that new characters seem to be particularly liable, from some unknown cause, to become attached to the male sex, have an important bearing on the acquirement of secondary sexual characters by animals in a state of nature.
It has sometimes been said that our domestic races do not differ in constitutional peculiarities, but this cannot be maintained. In our improved cattle, pigs, etc., the period of maturity, including that of the second dentition, has been much hastened. The period of gestation varies much, and has been modified in a fixed manner in one or two cases. In some breeds of poultry and pigeons the period at which the down and the first plumage are acquired, differs. The number of moults through which the larvae of silk-moths pass, varies. The tendency to fatten, to yield much milk, to produce many young or eggs at a birth or during life, differs in different breeds. We find different degrees of adaptation to climate, and different tendencies to certain diseases, to the attacks of parasites, and to the action of certain vegetable poisons. With plants, adaptation to certain soils, the power of resisting frost, the period of flowering and fruiting, the duration of life, the period of shedding the leaves or of retaining them throughout the winter, the proportion and nature of certain chemical compounds in the tissues or seeds, all vary.
There is, however, one important constitutional difference between domestic races and species; I refer to the sterility which almost invariably follows, in a greater or less degree, when species are crossed, and to the perfect fertility of the most distinct domestic races, with the exception of a very few plants, when similarly crossed. It is certainly a most remarkable fact that many closely-allied species, which in appearance differ extremely little, should yield when crossed only a few more or less sterile offspring, or none at all; whilst domestic races which differ conspicuously from each other are, when united, remarkably fertile, and yield perfectly fertile offspring. But this fact is not in reality so inexplicable as it at first appears. In the first place, it was clearly shown in the nineteenth chapter that the sterility of crossed species does not depend chiefly on differences in their external structure or general constitution, but on differences in the reproductive system, analogous to those which cause the lessened fertility of the illegitimate unions of dimorphic and trimorphic plants. In the second place, the Pallasian doctrine, that species after having been long domesticated lose their natural tendency to sterility when crossed, has been shown to be highly probable or almost certain. We cannot avoid this conclusion when we reflect on the parentage and present fertility of the several breeds of the dog, of the Indian or humped and European cattle, and of the two chief kinds of pigs. Hence it would be unreasonable to expect that races formed under domestication should acquire sterility when crossed, whilst at the same time we admit that domestication eliminates the normal sterility of crossed species. Why with closely-allied species their reproductive systems should almost invariably have been modified in so peculiar a manner as to be mutually incapable of acting on each other—though in unequal degrees in the two sexes, as shown by the difference in fertility between reciprocal crosses of the same species—we do not know, but may with much probability infer the cause to be as follows. Most natural species have been habituated to nearly uniform conditions of life for an incomparably longer time than have domestic races; and we positively know that changed conditions exert an especial and powerful influence on the reproductive system. Hence this difference may well account for the difference in the power of reproduction between domestic races when crossed and species when crossed. It is probably in chief part owing to the same cause that domestic races can be suddenly transported from one climate to another, or placed under widely different conditions, and yet retain in most cases their fertility unimpaired; whilst a multitude of species subjected to lesser changes are rendered incapable of breeding.
The offspring of crossed domestic races and of crossed species resemble each other in most respects, with the one important exception of fertility; they often partake in the same unequal degree of the characters of their parents, one of which is often prepotent over the other; and they are liable to reversion of the same kind. By successive crosses one species may be made to absorb completely another, and so it notoriously is with races. The latter resemble species in many other ways. They sometimes inherit their newly-acquired characters almost or even quite as firmly as species. The conditions leading to variability and the laws governing its nature appear to be the same in both. Varieties can be classed in groups under groups, like species under genera, and these under families and orders; and the classification may be either artificial,—that is, founded on any arbitrary character,—or natural. With varieties a natural classification is certainly founded, and with species is apparently founded, on community of descent, together with the amount of modification which the forms have undergone. The characters by which domestic varieties differ from one another are more variable than those distinguishing species, though hardly more so than with certain polymorphic species; but this greater degree of variability is not surprising, as varieties have generally been exposed within recent times to fluctuating conditions of life, and are much more liable to have been crossed; they are also in many cases still undergoing, or have recently undergone, modification by man’s methodical or unconscious selection.
Domestic varieties as a general rule certainly differ from one another in less important parts than do species; and when important differences occur, they are seldom firmly fixed; but this fact is intelligible, if we consider man’s method of selection. In the living animal or plant he cannot observe internal modifications in the more important organs; nor does he regard them as long as they are compatible with health and life. What does the breeder care about any slight change in the molar teeth of his pigs, or for an additional molar tooth in the dog; or for any change in the intestinal canal or other internal organ? The breeder cares for the flesh of his cattle being well marbled with fat, and for an accumulation of fat within the abdomen of his sheep, and this he has effected. What would the floriculturist care for any change in the structure of the ovarium or of the ovules? As important internal organs are certainly liable to numerous slight variations, and as these would probably be transmitted, for many strange monstrosities are inherited, man could undoubtedly effect a certain amount of change in these organs. When he has produced any modification in an important part, he has generally done so unintentionally, in correlation with some other conspicuous part. For instance, he has given ridges and protuberances to the skulls of fowls, by attending to the form of the comb, or to the plume of feathers on the head. By attending to the external form of the pouter-pigeon, he has enormously increased the size of the oesophagus, and has added to the number of the ribs, and given them greater breadth. With the carrier-pigeon, by increasing through steady selection the wattles on the upper mandible, he has greatly modified the form of the lower mandible; and so in many other cases. Natural species, on the other hand, have been modified exclusively for their own good, to fit them for infinitely diversified conditions of life, to avoid enemies of all kinds, and to struggle against a host of competitors. Hence, under such complex conditions, it would often happen that modifications of the most varied kinds, in important as well as in unimportant parts, would be advantageous or even necessary; and they would slowly but surely be acquired through the survival of the fittest. Still more important is the fact that various indirect modifications would likewise arise through the law of correlated variation.
Domestic breeds often have an abnormal or semi-monstrous character, as amongst dogs, the Italian greyhound, bulldog, Blenheim spaniel, and bloodhound,—some breeds of cattle and pigs,—several breeds of the fowl,—and the chief breeds of the pigeon. In such abnormal breeds, parts which differ but slightly or not at all in the allied natural species, have been greatly modified. This may be accounted for by man’s often selecting, especially at first, conspicuous and semi-monstrous deviations of structure. We should, however, be cautious in deciding what deviations ought to be called monstrous: there can hardly be a doubt that, if the brush of horse-like hair on the breast of the turkey-cock had first appeared in the domesticated bird, it would have been considered as a monstrosity; the great plume of feathers on the head of the Polish cock has been thus designated, though plumes are common on the heads of many kinds of birds; we might call the wattle or corrugated skin round the base of the beak of the English carrier-pigeon a monstrosity, but we do not thus speak of the globular fleshy excrescence at the base of the beak of the Carpophaga oceanica.
Some authors have drawn a wide distinction between artificial and natural breeds; although in extreme cases the distinction is plain, in many other cases it is arbitrary; the difference depending chiefly on the kind of selection which has been applied. Artificial breeds are those which have been intentionally improved by man; they frequently have an unnatural appearance, and are especially liable to lose their characters through reversion and continued variability. The so-called natural breeds, on the other hand, are those which are found in semi-civilised countries, and which formerly inhabited separate districts in nearly all the European kingdoms. They have been rarely acted on by man’s intentional selection; more frequently by unconscious selection, and partly by natural selection, for animals kept in semi-civilised countries have to provide largely for their own wants. Such natural breeds will also have been directly acted on by the differences, though slight, in the surrounding conditions.
There is a much more important distinction between our several breeds, namely, in some having originated from a strongly-marked or semi-monstrous deviation of structure, which, however, may subsequently have been augmented by selection; whilst others have been formed in so slow and insensible a manner, that if we could see their early progenitors we should hardly be able to say when or how the breed first arose. From the history of the racehorse, greyhound, gamecock, etc., and from their general appearance, we may feel nearly confident that they were formed by a slow process of improvement; and we know that this has been the case with the carrier-pigeon, as well as with some other pigeons. On the other hand, it is certain that the ancon and mauchamp breeds of sheep, and almost certain that the niata cattle, turnspit, and pug-dogs, jumper and frizzled fowls, short-faced tumbler pigeons, hook-billed ducks, etc., suddenly appeared in nearly the same state as we now see them. So it has been with many cultivated plants. The frequency of these cases is likely to lead to the false belief that natural species have often originated in the same abrupt manner. But we have no evidence of the appearance, or at least of the continued procreation, under nature, of abrupt modifications of structure; and various general reasons could be assigned against such a belief.
On the other hand, we have abundant evidence of the constant occurrence under nature of slight individual differences of the most diversified kinds; and we are thus led to conclude that species have generally originated by the natural selection of extremely slight differences. This process may be strictly compared with the slow and gradual improvement of the racehorse, greyhound, and gamecock. As every detail of structure in each species has to be closely adapted to its habits of life, it will rarely happen that one part alone will be modified; but, as was formerly shown, the co-adapted modifications need not be absolutely simultaneous. Many variations, however, are from the first connected by the law of correlation. Hence it follows that even closely-allied species rarely or never differ from one another by one character alone; and the same remark is to a certain extent applicable to domestic races; for these, if they differ much, generally differ in many respects.
Some naturalists boldly insist[[1]] that species are absolutely distinct productions, never passing by intermediate links into one another; whilst they maintain that domestic varieties can always be connected either with one another or with their parent-forms. But if we could always find the links between the several breeds of the dog, horse, cattle, sheep, pigs, etc., there would not have been such incessant doubts whether they were descended from one or several species. The greyhound genus, if such a term may be used, cannot be closely connected with any other breed, unless, perhaps, we go back to the ancient Egyptian monuments. Our English bulldog also forms a very distinct breed. In all these cases crossed breeds must of course be excluded, for distinct natural species can thus be likewise connected. By what links can the Cochin fowl be closely united with others? By searching for breeds still preserved in distant lands, and by going back to historical records, tumbler-pigeons, carriers, and barbs can be closely connected with the parent rock-pigeon; but we cannot thus connect the turbit or the pouter. The degree of distinctness between the various domestic breeds depends on the amount of modification which they have undergone, and more especially on the neglect and final extinction of intermediate and less-valued forms.
It has often been argued that no light is thrown on the changes which natural species are believed to undergo from the admitted changes of domestic races, as the latter are said to be mere temporary productions, always reverting, as soon as they become feral, to their pristine form. This argument has been well combated by Mr. Wallace[[2]] and full details were given in the thirteenth chapter, showing that the tendency to reversion in feral animals and plants has been greatly exaggerated, though no doubt it exists to a certain extent. It would be opposed to all the principles inculcated in this work, if domestic animals, when exposed to new conditions and compelled to struggle for their own wants against a host of foreign competitors, were not modified in the course of time. It should also be remembered that many characters lie latent in all organic beings, ready to be evolved under fitting conditions; and in breeds modified within recent times, the tendency to reversion is particularly strong. But the antiquity of some of our breeds clearly proves that they remain nearly constant as long as their conditions of life remain the same.
It has been boldly maintained by some authors that the amount of variation to which our domestic productions are liable is strictly limited; but this is an assertion resting on little evidence. Whether or not the amount of change in any particular direction is limited, the tendency to general variability is, as far as we can judge, unlimited. Cattle, sheep, and pigs have varied under domestication from the remotest period, as shown by the researches of Rutimeyer and others; yet these animals have been improved to an unparalleled degree, within quite recent times, and this implies continued variability of structure. Wheat, as we know from the remains found in the Swiss lake-dwellings, is one of the most anciently cultivated plants, yet at the present day new and better varieties frequently arise. It may be that an ox will never be produced of larger size and finer proportions, or a racehorse fleeter, than our present animals, or a gooseberry larger than the London variety; but he would be a bold man who would assert that the extreme limit in these respects has been finally attained. With flowers and fruit it has repeatedly been asserted that perfection has been reached, but the standard has soon been excelled. A breed of pigeons may never be produced with a beak shorter than that of the present short-faced tumbler, or with one longer than that of the English carrier, for these birds have weak constitutions and are bad breeders; but shortness and length of beak are the points which have been steadily improved during the last 150 years, and some of the best judges deny that the goal has yet been reached. From reasons which could be assigned, it is probable that parts which have now reached their maximum development, might, after remaining constant during a long period, vary again in the direction of increase under new conditions of life. But there must be, as Mr. Wallace has remarked with much truth,[[3]] a limit to change in certain directions both with natural and domestic productions; for instance, there must be a limit to the fleetness of any terrestrial animal, as this will be determined by the friction to be overcome, the weight to be carried, and the power of contraction in the muscular fibres. The English racehorse may have reached this limit; but it already surpasses in fleetness its own wild progenitor and all other equine species. The short-faced tumbler-pigeon has a beak shorter, and the carrier a beak longer, relatively to the size of their bodies, than that of any natural species of the family. Our apples, pears and gooseberries bear larger fruit than those of any natural species of the same genera; and so in many other cases.
It is not surprising, seeing the great difference between many domestic breeds, that some few naturalists have concluded that each is descended from a distinct aboriginal stock, more especially as the principle of selection has been ignored, and the high antiquity of man, as a breeder of animals, has only recently become known. Most naturalists, however, freely admit that our various breeds, however dissimilar, are descended from a single stock, although they do not know much about the art of breeding, cannot show the connecting links, nor say where and when the breeds arose. Yet these same naturalists declare, with an air of philosophical caution, that they will never admit that one natural species has given birth to another until they behold all the transitional steps. Fanciers use exactly the same language with respect to domestic breeds; thus, an author of an excellent treatise on pigeons says he will never allow that the carrier and fantail are the descendants of the wild rock-pigeon, until the transitions have “actually been observed, and can be repeated whenever man chooses to set about the task.” No doubt it is difficult to realise that slight changes added up during long centuries can produce such great results; but he who wishes to understand the origin of domestic breeds or of natural species must overcome this difficulty.
The causes which excite and the laws which govern variability have been discussed so lately, that I need here only enumerate the leading points. As domesticated organisms are much more liable to slight deviations of structure and to monstrosities than species living under their natural conditions, and as widely-ranging species generally vary more than those which inhabit restricted areas, we may infer that variability mainly depends on changed conditions of life. We must not overlook the effects of the unequal combination of the characters derived from both parents, or reversion to former progenitors. Changed conditions have an especial tendency to render the reproductive organs more or less impotent, as shown in the chapter devoted to this subject; and these organs consequently often fail to transmit faithfully the parental characters. Changed conditions also act directly and definitely on the organisation, so that all or nearly all the individuals of the same species thus exposed become modified in the same manner; but why this or that part is especially affected we can seldom or ever say. In most cases, however, a change in the conditions seems to act indefinitely, causing diversified variations in nearly the same manner as exposure to cold or the absorption of the same poison affects different individuals in different ways. We have reason to suspect that an habitual excess of highly-nutritious food, or an excess relatively to the wear and tear of the organisation from exercise, is a powerful exciting cause of variability. When we see the symmetrical and complex outgrowths, caused by a minute drop of the poison of a gall-insect, we may believe that slight changes in the chemical nature of the sap or blood would lead to extraordinary modifications of structure.
The increased use of a muscle with its various attached parts, and the increased activity of a gland or other organ, lead to their increased development. Disuse has a contrary effect. With domesticated productions, although their organs sometimes become rudimentary through abortion, we have no reason to suppose that this has ever followed solely from disuse. With natural species, on the contrary, many organs appear to have been rendered rudimentary through disuse, aided by the principle of the economy of growth together with intercrossing. Complete abortion can be accounted for only by the hypothesis given in the last chapter, namely, the final destruction of the germs or gemmules of useless parts. This difference between species and domestic varieties may be partly accounted for by disuse having acted on the latter for an insufficient length of time, and partly from their exemption from any severe struggle for existence entailing rigid economy in the development of each part, to which all species under nature are subjected. Nevertheless the law of compensation or balancement, which likewise depends on the economy of growth, apparently has affected to a certain extent our domesticated productions.
As almost every part of the organisation becomes highly variable under domestication, and as variations are easily selected both consciously and unconsciously, it is very difficult to distinguish between the effects of the selection of indefinite variations and the direct action of the conditions of life. For instance, it is possible that the feet of our water-dogs and of the American dogs which have to travel much over the snow, may have become partially webbed from the stimulus of widely extending their toes; but it is more probable that the webbing, like the membrane between the toes of certain pigeons, spontaneously appeared and was afterwards increased by the best swimmers and the best snow-travellers being preserved during many generations. A fancier who wished to decrease the size of his bantams or tumbler-pigeons would never think of starving them, but would select the smallest individuals which spontaneously appeared. Quadrupeds are sometimes born destitute of hair and hairless breeds have been formed, but there is no reason to believe that this is caused by a hot climate. Within the tropics heat often causes sheep to lose their fleeces; on the other hand, wet and cold act as a direct stimulus to the growth of hair; but who will pretend to decide how far the thick fur of arctic animals, or their white colour, is due to the direct action of a severe climate, and how far to the preservation of the best-protected individuals during a long succession of generations?
Of all the laws governing variability, that of correlation is one of the most important. In many cases of slight deviations of structure as well as of grave monstrosities, we cannot even conjecture what is the nature of the bond of connexion. But between homologous parts—between the fore and hind limbs—between the hair, hoofs, horns, and teeth—which are closely similar during their early development and which are exposed to similar conditions, we can see that they would be eminently liable to be modified in the same manner. Homologous parts, from having the same nature, are apt to blend together, and, when many exist, to vary in number.
Although every variation is either directly or indirectly caused by some change in the surrounding conditions, we must never forget that the nature of the organisation which is acted on, is by far the more important factor in the result. We see this in different organisms, which when placed under similar conditions vary in a different manner, whilst closely-allied organisms under dissimilar conditions often vary in nearly the same manner. We see this, in the same modification frequently reappearing in the same variety at long intervals of time, and likewise in the several striking cases given of analogous or parallel variations. Although some of these latter cases are due to reversion, others cannot thus be accounted for.
From the indirect action of changed conditions on the organisation, owing to the reproductive organs being thus affected—from the direct action of such conditions, and these will cause the individuals of the same species either to vary in the same manner, or differently in accordance with slight differences in their constitution—from the effects of the increased or decreased use of parts—and from correlation,—the variability of our domesticated productions is complicated to an extreme degree. The whole organisation becomes slightly plastic. Although each modification must have its own exciting cause, and though each is subjected to law, yet we can so rarely trace the precise relation between cause and effect, that we are tempted to speak of variations as if they arose spontaneously. We may even call them accidental, but this must be only in the sense in which we say that a fragment of rock dropped from a height owes its shape to accident.
It may be worth while briefly to consider the result of the exposure to unnatural conditions of a large number of animals of the same species and allowed to cross freely with no selection of any kind, and afterwards to consider the result when selection is brought into play. Let us suppose that 500 wild rock-pigeons were confined in their native land in an aviary and fed in the same manner as pigeons usually are; and that they were not allowed to increase in number. As pigeons propagate so rapidly, I suppose that a thousand or fifteen hundred birds would have to be annually killed. After several generations had been thus reared, we may feel sure that some of the young birds would vary, and the variations would tend to be inherited; for at the present day slight deviations of structure often occur and are inherited. It would be tedious even to enumerate the multitude of points which still go on varying or have recently varied. Many variations would occur in correlation with one another, as the length of the wing and tail feathers—the number of the primary wing-feathers, as well as the number and breadth of the ribs, in correlation with the size and form of the body—the number of the scutellae with the size of the feet—the length of the tongue with the length of the beak—the size of the nostrils and eyelids and the form of lower jaw in correlation with the development of wattle—the nakedness of the young with the future colour of the plumage—the size of the feet with that of the beak, and other such points. Lastly, as our birds are supposed to be confined in an aviary, they would use their wings and legs but little, and certain parts of the skeleton, such as the sternum, scapulae and feet, would in consequence become slightly reduced in size.
As in our assumed case many birds have to be indiscriminately killed every year, the chances are against any new variety surviving long enough to breed. And as the variations which arise are of an extremely diversified nature, the chances are very great against two birds pairing which have varied in the same manner; nevertheless, a varying bird even when not thus paired would occasionally transmit its character to its young; and these would not only be exposed to the same conditions which first caused the variation in question to appear, but would in addition inherit from their modified parent a tendency again to vary in the same manner. So that, if the conditions decidedly tended to induce some particular variation, all the birds might in the course of time become similarly modified. But a far commoner result would be, that one bird would vary in one way and another bird in another way; one would be born with a beak a little longer, and another with a shorter beak; one would gain some black feathers, another some white or red feathers. And as these birds would be continually intercrossing, the final result would be a body of individuals differing from each other in many ways, but only slightly; yet more than did the original rock-pigeons. But there would not be the least tendency towards the formation of several distinct breeds.
If two separate lots of pigeons were treated in the manner just described, one in England and the other in a tropical country, the two lots being supplied with different kinds of food, would they after many generations differ? When we reflect on the cases given in the twenty-third chapter, and on such facts as the difference in former times between the breeds of cattle, sheep, etc., in almost every district of Europe, we are strongly inclined to admit that the two lots would be differently modified through the influence of climate and food. But the evidence on the definite action of changed conditions is in most cases insufficient; and, with respect to pigeons, I have had the opportunity of examining a large collection of domesticated kinds, sent to me by Sir W. Elliot from India, and they varied in a remarkably similar manner with our European birds.
If two distinct breeds were mingled together in equal numbers, there is reason to suspect that they would to a certain extent prefer pairing with their own kind; but they would often intercross. From the greater vigour and fertility of the crossed offspring, the whole body would by this means become interblended sooner than would otherwise have occurred. From certain breeds being prepotent over others, it does not follow that the interblended progeny would be strictly intermediate in character. I have, also, proved that the act of crossing in itself gives a strong tendency to reversion, so that the crossed offspring would tend to revert to the state of the aboriginal rock-pigeon; and in the course of time they would probably be not much more heterogeneous in character than in our first case, when birds of the same breed were confined together.
I have just said that the crossed offspring would gain in vigour and fertility. From the facts given in the seventeenth chapter there can be no doubt of this fact; and there can be little doubt, though the evidence on this head is not so easily acquired, that long-continued close interbreeding leads to evil results. With hermaphrodites of all kinds, if the sexual elements of the same individual habitually acted on each other, the closest possible interbreeding would be perpetual. But we should bear in mind that the structure of all hermaphrodite animals, as far as I can learn, permits and frequently necessitates a cross with a distinct individual. With hermaphrodite plants we incessantly meet with elaborate and perfect contrivances for this same end. It is no exaggeration to assert that, if the use of the talons and tusks of a carnivorous animal, or of the plumes and hooks on a seed, may be safely inferred from their structure, we may with equal safety infer that many flowers are constructed for the express purpose of ensuring a cross with a distinct plant. From these various considerations, not to mention the result of a long series of experiments which I have tried, the conclusion arrived at in the chapter just referred to—namely, that great good of some kind is derived from the sexual concourse of distinct individuals—must be admitted.
To return to our illustration: we have hitherto assumed that the birds were kept down to the same number by indiscriminate slaughter; but if the least choice be permitted in their preservation, the whole result will be changed. Should the owner observe any slight variation in one of his birds, and wish to obtain a breed thus characterised, he would succeed in a surprisingly short time by careful selection. As any part which has once varied generally goes on varying in the same direction, it is easy, by continually preserving the most strongly marked individuals, to increase the amount of difference up to a high, predetermined standard of excellence. This is methodical selection.
If the owner of the aviary, without any thought of making a new breed, simply admired, for instance, short-beaked more than long-beaked birds, he would, when he had to reduce the number, generally kill the latter; and there can be no doubt that he would thus in the course of time sensibly modify his stock. It is improbable, if two men were to keep pigeons and act in this manner, that they would prefer exactly the same characters; they would, as we know, often prefer directly opposite characters, and the two lots would ultimately come to differ. This has actually occurred with strains or families of cattle, sheep, and pigeons, which have been long kept and carefully attended to by different breeders, without any wish on their part to form new and distinct sub-breeds. This unconscious kind of selection will more especially come into action with animals which are highly serviceable to man; for every one tries to get the best dogs, horses, cows, or sheep, without thinking about their future progeny, yet these animals would transmit more or less surely their good qualities to their offspring. Nor is any one so careless as to breed from his worst animals. Even savages, when compelled from extreme want to kill some of their animals, would destroy the worst and preserve the best. With animals kept for use and not for mere amusement, different fashions prevail in different districts, leading to the preservation, and consequently to the transmission, of all sorts of trifling peculiarities of character. The same process will have been pursued with our fruit-trees and vegetables, for the best will always have been the most largely cultivated, and will occasionally have yielded seedlings better than their parents.
The different strains, just alluded to, which have been actually produced by breeders without any wish on their part to obtain such a result, afford excellent evidence of the power of unconscious selection. This form of selection has probably led to far more important results than methodical selection, and is likewise more important under a theoretical point of view from closely resembling natural selection. For during this process the best or most valued individuals are not separated and prevented from crossing with others of the same breed, but are simply preferred and preserved; yet this inevitably leads to their gradual modification and improvement; so that finally they prevail, to the exclusion of the old parent-form.
With our domesticated animals natural selection checks the production of races with any injurious deviation of structure. In the case of animals which, from being kept by savages or semi-civilised people, have to provide largely for their own wants under different circumstances, natural selection will have played a more important part. Hence it probably is that they often closely resemble natural species.
As there is no limit to man’s desire to possess animals and plants more and more useful in any respect, and as the fancier always wishes, owing to fashions running into extremes, to produce each character more and more strongly pronounced, there is, through the prolonged action of methodical and unconscious selection, a constant tendency in every breed to become more and more different from its parent-stock; and when several breeds have been produced and are valued for different qualities, to differ more and more from each other. This leads to Divergence of Character. As improved sub-varieties and races are slowly formed, the older and less improved breeds are neglected and decrease in number. When few individuals of any breed exist within the same locality, close interbreeding, by lessening their vigour and fertility, aids in their final extinction. Thus the intermediate links are lost, and the remaining breeds gain in Distinctness of Character.
In the chapters on the Pigeon, it was proved by historical evidence and by the existence of connecting sub-varieties in distant lands that several breeds have steadily diverged in character, and that many old and intermediate sub-breeds have been lost. Other cases could be adduced of the extinction of domestic breeds, as of the Irish wolf-dog, the old English hound, and of two breeds in France, one of which was formerly highly valued.[[4]] Mr. Pickering remarks[[5]] that “the sheep figured on the most ancient Egyptian monuments is unknown at the present day; and at least one variety of the bullock, formerly known in Egypt, has in like manner become extinct.” So it has been with some animals and with several plants cultivated by the ancient inhabitants of Europe during the neolithic period. In Peru, Von Tschudi[[6]] found in certain tombs, apparently prior to the dynasty of the Incas, two kinds of maize not now known in the country. With our flowers and culinary vegetables, the production of new varieties and their extinction has incessantly recurred. At the present time improved breeds sometimes displace older breeds at an extraordinarily rapid rate; as has recently occurred throughout England with pigs. The Longhorn cattle in their native home were “suddenly swept away as if by some murderous pestilence,” by the introduction of Shorthorns.[[7]]
What grand results have followed from the long-continued action of methodical and unconscious selection, regulated to a certain extent by natural selection, we see on every side of us. Compare the many animals and plants which are displayed at our exhibitions with their parent-forms when these are known, or consult old historical records with respect to their former state. Most of our domesticated animals have given rise to numerous and distinct races, but those which cannot be easily subjected to selection must be excepted—such as cats, the cochineal insect, and the hive-bee. In accordance with what we know of the process of selection, the formation of our many races has been slow and gradual. The man who first observed and preserved a pigeon with its oesophagus a little enlarged, its beak a little longer, or its tail a little more expanded than usual, never dreamed that he had made the first step in the creation of a pouter, carrier, and fantail-pigeon. Man can create not only anomalous breeds, but others having their whole structure admirably co-ordinated for certain purposes, such as the racehorse and dray-horse, or the greyhound and bulldog. It is by no means necessary that each small change of structure throughout the body, leading towards excellence, should simultaneously arise and be selected. Although man seldom attends to differences in organs which are important under a physiological point of view, yet he has so profoundly modified some breeds, that assuredly, if found wild, they would be ranked as distinct genera.
The best proof of what selection has effected is perhaps afforded by the fact that whatever part or quality in any animal, and more especially in any plant, is most valued by man, that part or quality differs most in the several races. This result is well seen by comparing the amount of difference between the fruits produced by the several varieties of fruit-trees, between the flowers of our flower-garden plants, between the seeds, roots, or leaves of our culinary and agricultural plants, in comparison with the other and not valued parts of the same varieties. Striking evidence of a different kind is afforded by the fact ascertained by Oswald Heer[[8]] namely, that the seeds of a large number of plants,—wheat, barley, oats, peas, beans, lentils, poppies,—cultivated for their seed by the ancient Lake-inhabitants of Switzerland, were all smaller than the seeds of our existing varieties. Rütimeyer has shown that the sheep and cattle which were kept by the earlier Lake-inhabitants were likewise smaller than our present breeds. In the middens of Denmark, the earliest dog of which the remains have been found was the weakest; this was succeeded during the Bronze age by a stronger kind, and this again during the Iron age by one still stronger. The sheep of Denmark during the Bronze period had extraordinarily slender limbs, and the horse was smaller than our present animal.[[9]] No doubt in most of these cases the new and larger breeds were introduced from foreign lands by the immigration of new hordes of men. But it is not probable that each larger breed, which in the course of time has supplanted a previous and smaller breed, was the descendant of a distinct and larger species; it is far more probable that the domestic races of our various animals were gradually improved in different parts of the great Europaeo-Asiatic continent, and thence spread to other countries. This fact of the gradual increase in size of our domestic animals is all the more striking as certain wild or half-wild animals, such as red-deer, aurochs, park-cattle, and boars[[10]] have within nearly the same period decreased in size.
The conditions favourable to selection by man are,—the closest attention to every character,—long-continued perseverance,—facility in matching or separating animals,—and especially a large number being kept, so that the inferior individuals may be freely rejected or destroyed, and the better ones preserved. When many are kept there will also be a greater chance of the occurrence of well-marked deviations of structure. Length of time is all-important; for as each character, in order to become strongly pronounced, has to be augmented by the selection of successive variations of the same kind, this can be effected only during a long series of generations. Length of time will, also, allow any new feature to become fixed by the continued rejection of those individuals which revert or vary, and by the preservation of those which still inherit the new character. Hence, although some few animals have varied rapidly in certain respects under new conditions of life, as dogs in India and sheep in the West Indies, yet all the animals and plants which have produced strongly marked races were domesticated at an extremely remote epoch, often before the dawn of history. As a consequence of this, no record has been preserved of the origin of our chief domestic breeds. Even at the present day new strains or sub-breeds are formed so slowly that their first appearance passes unnoticed. A man attends to some particular character, or merely matches his animals with unusual care, and after a time a slight difference is perceived by his neighbours;—the difference goes on being augmented by unconscious and methodical selection, until at last a new sub-breed is formed, receives a local name, and spreads; but by this time its history is almost forgotten. When the new breed has spread widely, it gives rise to new strains and sub-breeds, and the best of these succeed and spread, supplanting other and older breeds; and so always onwards in the march of improvement.
When a well-marked breed has once been established, if not supplanted by still further improved sub-breeds, and if not exposed to greatly changed conditions of life inducing further variability or reversion to long-lost characters, it may apparently last for an enormous period. We may infer that this is the case from the high antiquity of certain races; but some caution is necessary on this head, for the same variation may appear independently after long intervals of time, or in distant places. We may safely assume that this has occurred with the turnspit-dog, of which one is figured on the ancient Egyptian monuments—with the solid-hoofed swine[[11]] mentioned by Aristotle—with five-toed fowls described by Columella—and certainly with the nectarine. The dogs represented on the Egyptian monuments, about 2000 B.C., show us that some of the chief breeds then existed, but it is extremely doubtful whether any are identically the same with our present breeds. A great mastiff sculptured on an Assyrian tomb, 640 B.C., is said to be the same with the dog still imported from Thibet into the same region. The true greyhound existed during the Roman classical period. Coming down to a later period, we have seen that, though most of the chief breeds of the pigeon existed between two and three centuries ago, they have not all retained exactly the same character to the present day; but this has occurred in certain cases in which no improvement was desired, for instance, in the case of the Spot and Indian ground-tumbler.
De Candolle[[12]] has fully discussed the antiquity of various races of plants; he states that the black seeded poppy was known in the time of Homer, the white-seeded sesamum by the ancient Egyptians, and almonds with sweet and bitter kernels by the Hebrews; but it does not seem improbable that some of these varieties may have been lost and reappeared. One variety of barley and apparently one of wheat, both of which were cultivated at an immensely remote period by the Lake-inhabitants of Switzerland, still exist. It is said[[13]] that “specimens of a small variety of gourd which is still common in the market of Lima were exhumed from an ancient cemetery in Peru.” De Candolle remarks that, in the books and drawings of the sixteenth century, the principal races of the cabbage, turnip, and gourd can be recognised: this might have been expected at so late a period, but whether any of these plants are absolutely identical with our present sub-varieties is not certain. It is, however, said that the Brussels sprout, a variety which in some places is liable to degeneration, has remained genuine for more than four centuries in the district where it is believed to have originated.[[14]]
In accordance with the views maintained by me in this work and elsewhere, not only the various domestic races, but the most distinct genera and orders within the same great class—for instance, mammals, birds, reptiles, and fishes—are all the descendants of one common progenitor, and we must admit that the whole vast amount of difference between these forms has primarily arisen from simple variability. To consider the subject under this point of view is enough to strike one dumb with amazement. But our amazement ought to be lessened when we reflect that beings almost infinite in number, during an almost infinite lapse of time, have often had their whole organisation rendered in some degree plastic, and that each slight modification of structure which was in any way beneficial under excessively complex conditions of life has been preserved, whilst each which was in any way injurious has been rigorously destroyed. And the long-continued accumulation of beneficial variations will infallibly have led to structures as diversified, as beautifully adapted for various purposes and as excellently co-ordinated, as we see in the animals and plants around us. Hence I have spoken of selection as the paramount power, whether applied by man to the formation of domestic breeds, or by nature to the production of species. I may recur to the metaphor given in a former chapter: if an architect were to rear a noble and commodious edifice, without the use of cut stone, by selecting from the fragments at the base of a precipice wedge-formed stones for his arches, elongated stones for his lintels, and flat stones for his roof, we should admire his skill and regard him as the paramount power. Now, the fragments of stone, though indispensable to the architect, bear to the edifice built by him the same relation which the fluctuating variations of organic beings bear to the varied and admirable structures ultimately acquired by their modified descendants.
Some authors have declared that natural selection explains nothing, unless the precise cause of each slight individual difference be made clear. If it were explained to a savage utterly ignorant of the art of building, how the edifice had been raised stone upon stone, and why wedge-formed fragments were used for the arches, flat stones for the roof, etc.; and if the use of each part and of the whole building were pointed out, it would be unreasonable if he declared that nothing had been made clear to him, because the precise cause of the shape of each fragment could not be told. But this is a nearly parallel case with the objection that selection explains nothing, because we know not the cause of each individual difference in the structure of each being.
The shape of the fragments of stone at the base of our precipice may be called accidental, but this is not strictly correct; for the shape of each depends on a long sequence of events, all obeying natural laws; on the nature of the rock, on the lines of deposition or cleavage, on the form of the mountain, which depends on its upheaval and subsequent denudation, and lastly on the storm or earthquake which throws down the fragments. But in regard to the use to which the fragments may be put, their shape may be strictly said to be accidental. And here we are led to face a great difficulty, in alluding to which I am aware that I am travelling beyond my proper province. An omniscient Creator must have foreseen every consequence which results from the laws imposed by Him. But can it be reasonably maintained that the Creator intentionally ordered, if we use the words in any ordinary sense, that certain fragments of rock should assume certain shapes so that the builder might erect his edifice? If the various laws which have determined the shape of each fragment were not predetermined for the builder’s sake, can it be maintained with any greater probability that He specially ordained for the sake of the breeder each of the innumerable variations in our domestic animals and plants;—many of these variations being of no service to man, and not beneficial, far more often injurious, to the creatures themselves? Did He ordain that the crop and tail-feathers of the pigeon should vary in order that the fancier might make his grotesque pouter and fantail breeds? Did He cause the frame and mental qualities of the dog to vary in order that a breed might be formed of indomitable ferocity, with jaws fitted to pin down the bull for man’s brutal sport? But if we give up the principle in one case,—if we do not admit that the variations of the primeval dog were intentionally guided in order that the greyhound, for instance, that perfect image of symmetry and vigour, might be formed,—no shadow of reason can be assigned for the belief that variations, alike in nature and the result of the same general laws, which have been the groundwork through natural selection of the formation of the most perfectly adapted animals in the world, man included, were intentionally and specially guided. However much we may wish it, we can hardly follow Professor Asa Gray in his belief “that variation has been led along certain beneficial lines,” like a stream “along definite and useful lines of irrigation.” If we assume that each particular variation was from the beginning of all time preordained, then that plasticity of organisation, which leads to many injurious deviations of structure, as well as the redundant power of reproduction which inevitably leads to a struggle for existence, and, as a consequence, to the natural selection or survival of the fittest, must appear to us superfluous laws of nature. On the other hand, an omnipotent and omniscient Creator ordains everything and foresees everything. Thus we are brought face to face with a difficulty as insoluble as is that of free will and predestination.
REFERENCES
[1] Godron, ‘De l’Espèce,’ 1859, tom. ii. p. 44, etc.
[2] ‘Journal Proc. Linn. Soc.,’ 1858, vol. iii. p. 60.
[3] ‘The Quarterly Journal of Science,’ Oct. 1867, p. 486.
[4] M. Rufz de Lavison, in ‘Bull. Soc. Imp. d’Acclimat.,’ Dec. 1862, p. 1009.
[5] ‘Races of Man,’ 1850, p. 315.
[6] ‘Travels in Peru,’ Eng. translat., p. 177.
[7] Youatt on Cattle, 1834, p. 200. On Pigs, see ‘Gardener’s Chronicle,’ 1854, p. 410.
[8] ‘Die Pflanzen der Pfahlbauten,’ 1865.
[9] Morlot, ‘Soc. Vaud. des Scien. Nat.,’ Mars, 1860, p. 298.
[10] Rütimeyer, ‘Die Fauna der Pfahlbauten,’ 1861, s. 30.
[11] Godron,’De l’Espèce,’ tom. i., 1859, p. 368.
[12] ‘Geographie Botan.,’ 1855, p. 989.
[13] Pickering, ‘Races of Man,’ 1850, p. 318.
[14] ‘Journal of a Horticultural Tour,’ by a Deputation of the Caledonian Hist. Soc., 1823, p. 293.
INDEX
ABBAS PACHA, a fancier of fantailed pigeons, [6].
ABBEY, Mr., on grafting, [18] (2);
—on mignonette, [21].
ABBOTT, Mr. Keith, on the Persian tumbler pigeon, [5].
ABBREVIATION of the facial bones, [3].
ABORTION of organs, [24], [27].
ABSORPTION of minority in crossed races, [15], [19].
ABUTILON, graft hybridisation of, [11].
ACCLIMATISATION, [24];
—of maize, [9].
ACERBI, on the fertility of domestic animals in Lapland, [16].
Achatinella, [13].
Achillea millefolium, bud variation in, [11].
Aconitum napellus, roots of, innocuous in cold climates, [23].
Acorus calamus, sterility of, [18].
ACOSTA, on fowls in South America at its discovery, [7].
Acropera, number of seeds in, [27].
ADAM, M., origin of Cytisus adami, [11].
ADAM, W., on consanguineous marriages, [17].
ADAMS, on hereditary diseases, [12].
ADVANCEMENT in scale of organisation, [Introduction].
Ægilops triticoides, observations of Fabre and Godron on, [9];
—increasing fertility of hybrids of, with wheat, [16].
Æsculus pavia, tendency of, to become double, [18].
Æthusa cynapium, [25].
AFFINITY, sexual elective, [19].
AFRICA, white bull from, [3];
—feral cattle in, [3];
—food-plants of savages of, [9];
—South, diversity of breeds of cattle in, [3];
—West, change in fleece of sheep in, [3].
Agave vivipara, seeding of, in poor soil, [18].
AGE, changes in trees, dependent on, [11].
——, as bearing on pangenesis, [27].
AGOUTI, fertility of, in captivity, [18].
AGRICULTURE, antiquity of, [21].
Agrostis, seeds of, used as food, [9].
AGUARA, [1].
AINSWORTH, Mr., on the change in the hair of animals at Angora, [24].
AKBAR KHAN, his fondness for pigeons, [6]; [20].
Alauda arvensis, [18].
ALBIN, on “Golden Hamburgh” fowls, [7];
—figure of the hook-billed duck, [8].
ALBINISM, [4], [12].
ALBINO, negro, attacked by insects, [21].
ALBINOES, heredity of, [12].
ALBINUS, thickness of the epidermis on the palms of the hands in man, [24].
ALCO, [1], [15].
ALDROVANDI, on rabbits, [4];
—description of the nun pigeon, [5];
—on the fondness of the Dutch for pigeons in the seventeenth century, [6];
—notice of several varieties of pigeons, [6];
—on the breeds of fowls, [7];
—on the origin of the domestic duck, [8].
ALEFIELD, Dr., on the varieties of peas and their specific unity, [9];
—on the varieties of beans, [9].
ALEXANDER the Great, his selection of Indian cattle, [20].
ALGÆ, retrogressive metamorphosis in, [27];
—division of zoospores of, [27].
ALLEN, J., birds in United States, [23].
ALLEN, W., on feral fowls, [7], [13].
ALLMAN, Professor, on a monstrous Saxifraga geum, [18];
—on the Hydroida, [27] (2).
ALMOND, [10];
—antiquity of, [28];
—bitter, not eaten by mice, [21].
Alnus glutinosa, and incana, hybrids of, [17].
ALPACA, selection of, [20].
Althæa rosea, [11], [16].
Amaryllis, [17].
Amaryllis vittata, effect of foreign pollen on, [5].
AMAUROSIS, hereditary, [12].
Amblystoma lurida, [27].
AMERICA, limits within which no useful plants have been furnished by, [9];
—colours of feral horses in, [2];
—North, native cultivated plants of, [9];
—skin of feral pig from, [3];
—South, variations in cattle of, [3].
AMMON, on the persistency of colour in horses, [12].
Amygdalus persica, [10], [11].
Anagallis arvensis, [19].
ANALOGOUS variation, [5], [22];
—in horses, [5];
—in the horse and ass, [2];
—in fowls, [7].
Anas boschas, [8], [13];
—skull of, figured, [8].
“ANCON” sheep of Massachusetts, [3], [15].
ANDALUSIAN fowls, [7].
ANDALUSIAN rabbits, [4].
ANDERSON, J., on the origin of British sheep, [4];
—on the selection of qualities in cattle, [20];
—on a one-eared breed of rabbits, [4];
—on the inheritance of characters from a one-eared rabbit, and three-legged bitch, [12];
—on the persistency of varieties of peas, [9];
—on the production of early peas by selection, [20];
—on the varieties of the potato, [9];
—on crossing varieties of the melon, [11];
—on reversion in the barberry, [11].
ANDERSON, Mr., on the reproduction of the weeping ash by seed, [12].
—on the cultivation of the tree pæony in China, [20].
ANDERSSON, Mr., on the Damara, Bechuana, and Namaqua cattle, [3];
—on the cows of the Damaras, [24];
—selection practised by the Damaras and Namaquas, [20];
—on the use of grass-seeds and the roots of reeds as food in South Africa, [9].
Anemone coronaria, doubled by selection, [20].
ANGINA pectoris, hereditary, occurring at a certain age, [14].
ANGLESEA, cattle of, [3].
ANGOLA sheep, [3].
ANGORA, change in hair of animals at, [23];
—cats of, [1] (2);
—rabbits of, [4] (2).
ANIMALS, domestication of, facilitated by fearlessness of man, [1];
—refusal of wild, to breed in captivity, [18];
—compound, individual peculiarities of, reproduced by budding, [11];
—variation by selection in useful qualities of, [20].
ANNUAL plants, rarity of bud-variation in, [11].
ANOMALIES in the osteology of the horse, [2].
ANOMALOUS breeds of pigs, [3];
—of cattle, [3].
Anser albifrons, characters of, reproduced in domestic geese, [8].
Anser ægyptiacus, [8], [14].
Anser canadensis, [18]. Anser ferus, the original of the domestic goose, [8];
—fertility of cross of, with domestic goose, [8].
ANSON, on feral fowls in the Ladrones, [7].
ANTAGONISM between growth and reproduction, [27].
Anthemis nobilis, bud-variation in flowers of, [11];
—becomes single in poor soil, [18].
ANTHERS, contabescence of, [18].
ANTIGUA, cats of, [5];
—changed fleece of sheep in, [3].
Antirrhinum majus, peloric, [10], [13] (2), [18];
—double-flowered, [18];
—bud-variation in, [11].
ANTS, individual recognition of, [22].
APHIDES, attacking pear-trees, [21];
—development of, [27].
APOPLEXY, hereditary, occurring at a certain age, [14].
APPLE, [10];
—fruit of, in Swiss lake-dwellings, [9];
—rendered fastigiate by heat in India, [10];
—bud-variation in the, [11];
—with dimidiate fruit, [11] (2);
—with two kinds of fruit on the same branch, [11];
—artificial fecundation of, [11];
—St. Valéry, [11], [18];
—reversion in seedlings of, [13];
—crossing of varieties of, [17];
—growth of the, in Ceylon, [21];
—winter majetin, not attacked by coccus, [21];
—flower-buds of, attacked by bullfinches, [21];
—American, change of, when grown in England, [23].
APRICOT, [10] (2);
—glands on the leaves of, [21];
—analogous variation in the, [26].
Aquila fusca, copulating in captivity, [18].
Aquilegia vulgaris, [10], [25].
ARAB boarhound, described by Harcourt, [1].
Arabis blepharophylla and A. soyeri, effects of crossing, [11].
Aralia trifoliata, bud-variation in leaves of, [11].
ARAUCARIAS, young, variable resistance of, to frost, [24].
ARCHANGEL pigeon, [21].
ARCTIC regions, variability of plants and shells of, [22].
Aria vestita, grafted on thorns, [11].
ARISTOPHANES, fowls mentioned by, [7].
ARISTOTLE, on solid-hoofed pigs, [3];
—domestic duck unknown to, [8];
—on the assumption of male characters by old hens, [13].
ARNI, domestication of the, [3].
ARNOLD, Mr., experiments of pollen on the maize, [11].
ARRESTS of development, [24].
ARTERIES, increase of anastomosing branches of, when tied, [24].
ARU Islands, wild pig of, [3].
ARUM, Polynesian varieties of, [22].
Ascaris, number of eggs of, [27].
ASH, varieties of the, [10];
—weeping, [10];
—simple-leaved, [10];
—bud-variation in, [11];
—effects of graft upon the stock in the, [11];
—production of the blotched Breadalbane, [11];
—weeping, capricious reproduction of, by seed, [12].
Asinus burchellii, [2].
Asinus hemionus, [13].
Asinus indicus, [13] (2).
Asinus quagga, [2].
Asinus tæniopus, the original of the domestic ass, [2].
ASPARAGUS, increased fertility of cultivated, [16].
ASS, early domestication of the, [2];
—breeds of, [2];
—small size of, in India, [2];
—stripes of, [2] (2);
—dislike of, to cross water, [6];
—reversion in, [13] (3);
—hybrid of the, with mare and zebra, [13];
—prepotency of the, over the horse, [14];
—crossed with wild ass, [20];
—variation and selection of the, [21].
ASSYRIAN sculpture of a mastiff, [1].
ASTERS, [12], [24].
ASTHMA, hereditary, [12], [14].
ATAVISM. See Reversion.
ATHELSTAN, his care of horses, [20].
ATKINSON, Mr., on the sterility of the Tarroo silk-moth in confinement, [18].
AUBERGINE, [15].
AUDUBON, on feral hybrid ducks, [6], [13];
—on the domestication of wild ducks on the Mississippi, [8];
—on the wild cock turkey visiting domestic hens, [8];
—fertility of Fringilla ciris in captivity, [18];
—fertility of Columba migratoria and leucocephala in captivity, [18];
—breeding of Anser canadensis in captivity, [18].
AUDUBON and Bachman, on the change of coat in Ovis montana, [3];
—sterility of Sciurus cinerea in confinement, [18].
AURICULA, effect of seasonal conditions on the, [23];
—blooming of, [26].
AUSTRALIA, no generally useful plants derived from, [9];
—useful plants of, enumerated by Hooker, [9].
AUSTRIA, heredity of character in emperors of, [14].
AUTENRIETH, on persistency of colour in horses, [12].
AVA, horses of, [2].
Avena fatua, cultivability of, [9].
‘AYEEN Akbery,’ pigeons mentioned in the, [5] (2), [6] (4).
AYRES, W. P., on bud-variation in pelargoniums, [11].
Azalea indica, bud-variation in, [11].
AZARA, on the feral dogs of La Plata, [1];
—on the crossing of domestic with wild cats in Paraguay, [1];
—on hornlike processes in horses, [2];
—on curled hair in horses, [2];
—on the colours of feral horses, [2];
—on the cattle of Paraguay and La Plata, [3] (3), [22];
—on a hornless bull, [20];
—on the increase of cattle in South America, [17];
—on the growth of horns in the hornless cattle of Corrientes, [13];
—on the “Niata” cattle, [3];
—on naked quadrupeds, [23];
—on a race of black-skinned fowls in South America, [7], [20];
—on a variety of maize, [9].
BABINGTON, C. C., on the origin of the plum, [10];
—British species of the genus Rosa, [10];
—distinctness of Viola lutea and tricolor, [10].
BACHMANN, Mr., on the turkey, [22].
See also Audubon. BADGER, breeding in confinement, [18].
“BAGADOTTEN-TAUBE,” [5].
BAILY, Mr., on the effect of selection on fowls, [20];
—on Dorking fowls, [21].
BAIRD, S., on the origin of the turkey, [8].
BAKER, Mr., on heredity in the horse, [12];
—on the degeneration of the horse by neglect, [21];
—orders of Henrys VII. and VIII. for the destruction of undersized mares, [20].
BAKEWELL, change in the sheep effected by, [20].
BALANCEMENT, [26] (2);
—of growth, law of, [26].
BALDHEAD (pigeon), [5].
BALDNESS, in man, inherited, [25];
—with deficiency in teeth, [25] (2).
BALLANCE, Mr., on the effects of interbreeding on fowls, [17];
—on variation in the eggs of fowls, [7].
Ballota nigra, transmission of variegated leaves in, [11].
BAMBOO, varieties of the, [22].
BANANA, variation of the, [10], [22];
—bud-variation in the, [11];
—sterility of the, [22].
BANTAM fowls, [7];
—Sebright, origin of, [15];
—sterility of, [16].
BARB (pigeon), [5] (2), [6], [21];
—figure of, [5];
—figure of lower jaw of, [5].
BARBS, of wheat, [9].
BARBERRY, dark or red-leaved variety, [10], [12];
—reversion in suckers of seedless variety, [11].
BARBUT, J., on the dogs of Guinea, [1];
—on the domestic pigeons in Guinea, [6];
—fowls not native in Guinea, [7].
BARKING, acquisition of the habit of, by various dogs, [1].
BARLEY, wild, [9];
—of the lake-dwellings, [9];
—ancient variety of, [28].
BARNES, Mr., production of early peas by selection, [20].
BARNET, Mr., on the intercrossing of strawberries, [10];
—diœciousness of the hautbois strawberry, [10];
—on the Scarlet American strawberry, [20].
BARTH, Dr., use of grass-seeds as food in Central Africa, [9].
BARTLETT, A. D., on the origin of “Himalayan” rabbits by intercrossing, [4];
—on the feral rabbits of Porto Santo, [4];
—on geese with reversed feathers on the head and neck, [8];
—on the young of the black-shouldered peacock, [8];
—on a variety of the turkey, [8];
—size of hybrids, [17];
—on the breeding of the Felidæ in captivity, [18];
—so-called hybrids, [25].
BARTRAM, on the black wolf-dog of Florida, [1].
BATES, H. W., refusal of wild animals to breed in captivity, [18] (2);
—sterility of American monkeys in captivity, [18];
—sterility of tamed guans, [18].
BATRACHIA, regeneration of lost parts in, [27].
BEACH, raised, in Peru, containing heads of maize, [9].
BEAK, variability of, in fowls, [7];
—individual differences of, in pigeons, [5];
—correlation of, with the feet in pigeons, [5].
BEALE, Lionel, on the contents of cells, [27];
—on the multiplication of infectious atoms, [27].
BEANS, [9];
—of Swiss lake-dwellings, [9];
—varieties of, produced by selection, [20];
—French and scarlet, variable resistance of, to frost, [24] (2);
—superiority of native seed of, [24];
—a symmetrical variation of scarlet, [27];
—experiments on kidney, [8];
—with monstrous stipules and abortive leaflets, [26].
BEARD pigeon, [5].
BEARS, breeding in captivity, [18].
BEASLEY, J., reversion in crossed cattle, [13].
BEATON, D., effect of soil upon strawberries, [10];
—on varieties of pelargonium, [10], [23] (2);
—bud-variation in Gladiolus colvilii, [11];
—cross between Scotch kail and cabbage, [15];
—hybrid gladiolus, [17];
—constant occurrence of new forms among seedlings, [21];
—on the doubling of the Compositæ, [24].
BECHUANA cattle, [3].
BECHSTEIN, on the burrowing of wolves, [1];
—Spitz Dog, [1];
—origin of the Newfoundland dog, [1];
—crossing of domestic and wild swine, [3];
—on the Jacobin pigeon, [5], [6];
—notice of swallow-pigeons, [5];
—on a fork-tailed pigeon, [5];
—variations in the colour of the croup in pigeons, [6];
—on the German dovecot pigeon, [6];
—fertility of mongrel-pigeons, [6];
—on hybrid turtle-doves, [6];
—on crossing the pigeon with Columba œnas, C. palumbus, Turtur risoria, and T. vulgaris, [6];
—development of spurs in the silk hen, [7];
—on Polish fowls, [7] (2);
—on crested birds, [7];
—on the canary-bird, [8], [12], [18];
—German superstition about the turkey, [8];
—occurrence of horns in hornless breeds of sheep, [13];
—hybrids of the horse and ass, [14];
—crosses of tailless fowls, [15];
—difficulty of pairing dove-cot and fancy pigeons, [16];
—fertility of tame ferrets and rabbits, [16];
—fertility of wild sow, [16];
—difficulty of breeding caged birds, [18];
—comparative fertility of Psittacus erithacus in captivity, [18];
—on changes of plumage in captivity, [18];
—liability of light-coloured cattle to the attacks of flies, [21];
—want of exercise a cause of variability, [22];
—effect of privation of light upon the plumage of birds, [23];
—on a sub-variety of the monk-pigeon, [26].
BECK, Mr., constitutional differences in pelargoniums, [10].
BECKMANN, on changes in the odours of plants, [23].
BEDDOE, Dr., correlation of complexion with consumption, [25].
BEE, persistency of character of, [21], [22];
—intercrossing, [17];
—conveyance of pollen of peas by, [9].
BEE OPHRYS, self-fertilisation of, [15].
BEECH, dark-leaved, [10], [12];
—fern-leaved, reversion of, [11];
—weeping, non-production of, by seed, [12].
BEECHEY, horses of Loochoo Islands, [2].
BEET, [9];
—increase of sugar in, by selection, [20].
Begonia frigida, singular variety of, [10];
—sterility of, [18].
BELGIAN rabbit, [4].
BELL, T., statement that white cattle have coloured ears, [3].
BELL, W., bud-variation in Paritium tricuspis, [11].
BELLINGERI, observations on gestation in the dog, [1]
—on the fertility of dogs and cats, [16].
BELON, on high-flying pigeons in Paphlagonia, [6];
—varieties of the goose, [8].
BENGUELA, cattle of, [3].
BENNETT, Dr. G., pigs of the Pacific Islands, [3], [15];
—dogs of the Pacific Islands, [15];
—varieties of cultivated plants in Tahiti, [22].
BENNETT, Mr., on the fallow deer, [16].
BENTHAM, G., number and origin of cultivated plants, [9];
—on Phaseolus, [9];
—cereals all cultivated varieties, [9];
—species of the orange group, [10];
—distinctions of almond and peach, [10];
—British species of Rosa, [10];
—identity of Viola lutea and tricolor, [10].
Berberis vulgaris, [11], [12].
Berberis wallichii, indifference of, to climate, [18].
BERJEAU, on the history of the dog, [1] (2).
BERKELEY, G. F., production of hen-cocks in a strain of game-fowls, [7].
BERKELEY, M. J., crossing of varieties of the pea, [11];
—effect of foreign pollen on grapes, [11];
—on hybrid plants, [17];
—analogy between pollen of highly-cultivated plants and hybrids, [22];
—on Hungarian kidney-beans, [23];
—failure of Indian wheat in England, [24].
BERNARD, inheritance of disease in the horse, [12].
BERNARD, C., independence of the organs of the body, [27];
—special affinities of the tissues, [27].
BERNHARDI, varieties of plants with laciniated leaves, [26].
Bernicla antarctica, [8].
BERTERO, on feral pigeons in Juan Fernandez, [6].
Betula alba, [12].
BEWICK, on the British wild cattle, [3].
BIANCONI, Prof., on the skulls of dogs, [1].
BIBLE, reference to breeding studs of horses in, [2];
—references to domestic pigeons in the, [6];
—indications of selection of sheep in the, [20];
—notice of mules in the, [20].
BIDWELL, Mr., on self-impotence in Amaryllis, [17].
Bignonia, self-sterility of, [17].
BIRCH, weeping, [11], [12].
BIRCH, Dr. S., on the ancient domestication of the pigeon in Egypt, [6];
—notice of bantam fowls in a Japanese encyclopædia, [7] (2).
BIRCH, WYRLEY, on silver-grey rabbits, [4] (2).
BIRDS, sterility caused in, by change of conditions, [18].
BLADDER-NUT, tendency of the, to become double, [18].
BLAINE, Mr., on wry-legged terriers, [21].
BLAINVILLE, origin and history of the dog, [1];
—variations in the number of teeth in dogs, [1];
—variations in the number of toes in dogs, [1];
—on mummies of cats, [1];
—on the osteology of solid-hoofed pigs, [3];
—on feral Patagonian and N. American pigs, [3].
“BLASS-TAUBE,” [5]
BLEEDING, hereditary, [12];
—sexual limitation of excessive, [14].
BLENDING of crossed races, time occupied by the, [15].
BLINDNESS, hereditary, [12];
—at a certain age, [14];
—associated with colour of hair, [25].
BLOODHOUNDS, degeneration of, caused by interbreeding, [17].
BLUMENBACH, on the protuberance of the skull in Polish fowls, [7];
—on the effect of circumcision, [12];
—inheritance of a crooked finger, [12];
—on badger-dogs and other varieties of the dog, [20];
—on Hydra, [24];
—on the “nisus formativus,” [24].
BLYTH, E., on the pariah dog, [1];
—hybrids of dog and jackal, [1];
—early domestication of cats in India, [1];
—origin of domestic cat, [1];
—crossing of domestic and wild cats, [1];
—on Indian cats resembling Felis chaus, [1];
—on striped Burmese ponies, [2];
—on the stripes of the ass, [2];
—on Indian wild pigs, [3];
—on humped cattle, [3];
—occurrence of Bos frontosus in Irish crannoges, [3];
—fertile crossing of zebus and common cattle, [3];
—on the species of sheep, [3];
—on the fat-tailed Indian sheep, [3];
—origin of the goat, [3];
—on rabbits breeding in India, [4];
—number of tail-feathers in fantails, [5];
—Lotan tumbler pigeons, [5];
—number of tail-feathers in Ectopistes, [2];
—on Columba affinis, [6];
—pigeons roosting in trees, [6];
—on Columba leuconota, [6];
—on Columba intermedia of Strickland, [6];
—variation in colour of croup in pigeons, [6] (3);
—voluntary domestication of rock-pigeons in India, [6];
—feral pigeons on the Hudson, [6];
—occurrence of sub-species of pigeons, [6];
—notice of pigeon-fanciers in Delhi, etc., [6];
—hybrids of Gallus sonneratii and the domestic hen, [7];
—supposed hybridity of Gallus temminckii, [7];
—variations and domestication of Gallus bankiva, [7] (2);
—crossing of wild and tame fowls in Burmah, [7];
—restricted range of the larger gallinaceous birds, [7];
—feral fowls in the Nicobar Islands, [7];
—black-skinned fowls occurring near Calcutta, [7];
—weight of Gallus bankiva, [7];
—degeneration of the turkey in India, [8], [23];
—on the colour of gold-fish, [8];
—reversion from a cross, [13];
—on the Ghor-Khur (Asinus indicus), [13];
—on Asinus hemionus, [13];
—number of eggs of Gallus bankiva, [16];
—on the breeding of birds in captivity, [18];
—co-existence of large and small breeds in the same country, [23];
—on the drooping ears of the elephant, [24];
—homology of leg and wing feathers, [25].
BOETHIUS on Scotch wild cattle, [3].
BOITARD and Corbié, on the breeds of pigeons, [5];
—Lille pouter pigeon, [5];
—notice of a gliding pigeon, [5];
—variety of the pouter pigeon, [5];
—dove-cot pigeon, [6];
—crossing pigeons, [6], [15], [17];
—sterility of hybrids of turtle-doves, [6];
—reversion of crossed pigeons, [6], [13];
—on the fantail, [6], [14];
—on the trumpeter, [14];
—prepotency of transmission in silky fantail, [14] (2);
—secondary sexual characters in pigeons, [14];
—crossing of white and coloured turtle-doves, [15];
—fertility of pigeons, [16].
BOMBYCIDÆ, wingless females of, [24].
Bombyx hesperus, [24].
Bombyx huttoni, [8].
Bombyx mori, [8].
BONAFOUS, on maize, [9]. BONAPARTE, number of species of Columbidæ, [5];
—number of tail-feathers in pigeons, [5];
—size of the feet in Columbidæ, [5];
—on Columba guinea, [6];
—Columba turricola, rupestris and schimperi, [6].
Bonatea speciosa, development of ovary of, [11].
BONAVIA, Dr., growth of cauliflowers in India, [24].
BONER, Mr., semi-feral sheep, [13].
BONES, removal of portions of, [24];
—regeneration of, [24];
—growth and repair of, [27].
BONIZZI, on pigeons, [5] (2).
BONNET, on the salamander, [27];
—theory of reproduction, [27] (2).
BORCHMEYER, experiments with the seeds of the weeping ash, [12].
BORECOLE, [9].
BORELLI, on Polish fowls, [7].
BORNEO, fowls of, with tail-bands, [7].
BORNET, E., condition of the ovary in hybrid Cisti, [11];
—self-impotence of hybrid Cisti, [17].
BORROW, G., on pointers, [1].
BORY DE SAINT-VINCENT, on gold-fish, [8].
Bos, probable origin of European domestic cattle from three species of, [3].
Bos frontosus, [3].
Bos indicus, [3].
Bos longifrons, [3] (3).
Bos primigenius, [3] (2), [17]. Bos sondaicus, [20].
Bos taurus, [3].
Bos trochoceros, [3].
BOSC, heredity in foliage-varieties of the elm, [10].
BOSSE, production of double flowers from old seed, [18].
BOSSI, on breeding dark-coloured silkworms, [8].
BOSMAN, on dogs of Guinea, [1].
BOUCHARDAT, on the vine disease, [10].
BOUDIN, on local diseases, [23];
—resistance to cold of dark-complexioned men, [25].
“BOULANS,” [5].
“BOUTON d’Alep,” [23].
BOWEN, Prof., doubts as to the importance of inheritance, [12].
BOWMAN, Mr., hereditary peculiarities in the human eye, [12];
—hereditary cataract, [14].
BRACE, Mr., on Hungarian cattle, [3].
Brachycome iberidifolia, [22].
BRACTS, unusual development of, in gooseberries, [10].
BRADLEY, Mr., effect of grafts upon the stock in the ash, [11];
—effect of foreign pollen upon apples, [11];
—on change of soil, [18].
“BRAHMA Pootras,” a new breed of fowls, [7].
BRAIN, proportion of, in hares and rabbits, [4].
BRANDT, Dr., origin of the goat, [3];
—correlation of teeth and hair, [25].
Brassica, varieties of, with enlarged stems, [26].
Brassica asperifolia, [26].
Brassica napus, [9].
Brassica oleracea, [9].
Brassica rapa, [9], [18].
BRAUN, A., bud-variation in the vine, [11];
—in the currant, [11];
—in Mirabilis jalapa, [11];
—in Cytisus adami, [11];
—on reversion in the foliage of trees, [11];
—spontaneous production of Cytisus purpureo-elongatus, [11];
—reversion of flowers by stripes and blotches, [13];
—excess of nourishment a source of variability, [22].
BRAZIL, cattle of, [3].
BREAD-FRUIT, varieties of, [22];
—sterility and variability of, [22].
BREE, W. T., bud-variation in Geranium pratense and Centaurea cyanus, [11];
—by tubers in the dahlia, [11];
—on the deafness of white cats with blue eyes, [25].
BREEDING, high, dependent on inheritance, [12] (2).
BREEDS, domestic, persistency of, [21];
—artificial and natural, [28] (2);
—extinction of, [28];
—of domestic cats, [1];
—of pigs produced by crossing, [3];
—of cattle, [3] (2);
—of goats, [3].
BREHM, on Columba amaliæ, [6].
BRENT, B. P., number of mammæ in rabbits, [4];
—habits of the tumbler pigeon, [5];
—Laugher pigeon, [5];
—colouring of the kite tumbler, [5];
—crossing of the pigeon with Columba œnas, [6];
—mongrels of the trumpeter pigeon, [14];
—close interbreeding of pigeons, [17];
—opinion on Aldrovandi’s fowls, [7];
—on stripes in chickens, [7];
—on the combs of fowls, [7];
—double-spurred Dorking fowls, [7];
—effect of crossing on colour of plumage in fowls, [7];
—-incubatory instinct of mongrels between non-setting varieties of fowls, [13];
—origin of the domestic duck, [8];
—fertility of the hook-billed duck, [8];
—occurrence of the plumage of the wild duck in domestic breeds, [8];
—voice of ducks, [8];
—occurrence of a short upper mandible in crosses of hook-billed and common ducks, [8];
—reversion in ducks produced by crossing, [13];
—variation of the canary-bird, [8];
—fashion in the canary, [21];
—hybrids of canary and finches, [13].
BRICKELL, on raising nectarines from seed, [4];
—on the horses of North Carolina, [24].
BRIDGES, Mr., on the dogs of Tierra del Fuego, [1];
—on the selection of dogs by the Fuegians, [20].
BRIDGMAN, W. K., reproduction of abnormal ferns, [11].
BROCA, P., on the intercrossing of dogs, [1] (2);
—on hybrids of hare and rabbit, [4];
—on the rumpless fowl, [7];
—on the character of half-castes, [13];
—degree of fertility of mongrels, [16];
—sterility of descendants of wild animals bred in captivity, [18].
BROCCOLI, [9];
—rudimentary flowers in, [24];
—tenderness of, [24].
BROMEHEAD, W., doubling of the Canterbury Bell by selection, [20].
BROOMFIELD, Dr., sterility of the ivy and Acorus calamus, [18].
Bromus secalinus, [9].
BRONN, H. G., bud variation in Anthemis, [11];
—effects of cross-breeding on the female, [11];
—on heredity in a one-horned cow, [12];
—propagation of a pendulous peach by seed, [12];
—absorption of the minority in crossed races, [15];
—on the crossing of horses, [15];
—fertility of tame rabbits and sheep, [16];
—changes of plumage in captivity, [18];
—on the dahlia, [22].
BRONZE period, dog of, [1].
BROWN, C. M., prepotency of a greyhound, [14].
BROWN, G., variations in the dentition of the horse, [2].
BROWN-SÉQUARD, Dr., inheritance of artificially-produced epilepsy in the guinea-pig, [12];
—inherited effects of injuries, [12].
Brunswigia, [17].
BRUSSELS sprouts, [9], [28].
Bubo maximus, [18].
BUCKLAND, F., on oysters, [23];
—number of eggs in a codfish, [27].
BUCKLE, Mr., doubts as to the importance of inheritance, [12].
BUCKLEY, Miss, carrier-pigeons roosting in trees, [6].
BUCKMAN, Prof., cultivation of Avena fatua, [9];
—cultivation of the wild parsnip, [9], [20], [23];
—reversion in the parsnip, [13].
BUCKWHEAT, injurious when in flower to white pigs, [25].
BUD and seed, close analogy of, [11].
BUD-REVERSION, [13].
BUDS, adventitious, [27].
BUD-VARIATION, [11], [22], [23] (3);
—contrasted with seminal reproduction, [11];
—peculiar to plants, [11];
—in the peach, [10];
—in plums, [11];
—in the cherry, [11];
—in grapes, [11];
—in the gooseberry and currant, [11];
—pear and apple, [11];
—and in the banana, camellia, hawthorn, Azalea indica, and Paritium tricuspis, [11];
—in the hollyhock and pelargonium, [11];
—in Geranium pratense and the chrysanthemum, [11];
—in roses, [10], [11];
—in sweet williams, carnations, pinks, stocks, and snapdragons, [11] (2);
—in wall-flowers, cyclamen, Œnothera biennis, Gladiolus colvillii, fuchsias, and Mirabilis jalapa, [11];
—in foliage of various trees, [11];
—cryptogamic plants, [11];
—by suckers in Phlox and barberry, [11];
—by tubers in the potato, [11];
—in the dahlia, [11];
—by bulbs in hyacinths, Imatophyllum miniatum, and tulips, [11];
—in Tigridia conchiflora, [11];
—in Hemerocallis, [11];
—doubtful cases, [11];
—in Cytisus adami, [11];
—summary of observations on, [11].
BUFFON, on crossing the wolf and dog, [1];
—increase of fertility by domestication, [16];
—improvement of plants by unconscious selection, [20];
—theory of reproduction, [27].
Bulimus, [13].
BULL, apparent influence of, on offspring, [14].
BULLACE, [10].
BULLDOG, degeneration of, in India, [1];
—recent modifications of, [1].
BULLFINCH, breeding in captivity, [18];
—attacking flower-buds, [21].
BULT, Mr., on the length of pouter pigeons, [6].
“BUNDTNERSCHWEIN,” [3].
BUNTING, reed, in captivity, [18].
BURDACH, crossing of domestic and wild animals, [3];
—aversion of the wild boar to barley, [24].
BURKE, Mr., inheritance in the horse, [12].
Burlingtonia, [17].
BURMAH, cats of, [1].
BURMESE ponies, striped, [2].
BURNES, Sir A., on the Karakool sheep, [3], [23];
—varieties of the vine in Cabool, [10];
—hawks, trained in Scinde, [18];
—pomegranates producing seed, [18].
BURR, FEARING, potato-grafting, [11].
BURTON CONSTABLE, wild cattle at, [3].
“BURZEL-TAUBEN,” [5].
BUSSORAH carrier, [5].
Buteo vulgaris, copulation of, in captivity, [18].
BUTTERFLIES, polymorphic, [27].
BUXTON, Mr., parrots breeding in Norfolk, [18].
BUZAREINGUES, GIROU DE, inheritance of tricks, [12].
CABANIS, pears grafted on the quince, [22].
CABBAGE, [9];
—varieties of, [9];
—unity of character in flowers and seeds of, [9];
—cultivated by ancient Celts, [9];
—classification of varieties of, [9];
—ready crossing of, [9], [15] (2), [17];
—origin of, [9];
—increased fertility of, when cultivated, [16];
—growth of, in tropical countries, [23].
CABOOL, vines of, [10].
CABRAL, on early cultivation in Brazil, [9].
CACTUS, growth of cochineal on, in India, [23].
CÆSAR, Bos primigenius wild in Europe in the time of, [3];
—notice of fowls in Britain, [7];
—notice of the importation of horses by the Celts, [20].
CAFFRE fowls, [7].
CAFFRES, different kinds of cattle possessed by the, [3].
“CÁGIAS” a breed of sheep, [3].
Cairina moschata, [6].
CALCEOLARIAS, [10], [18];
—effects of seasonal conditions on, [23];
—peloric flowers in, [26].
CALDWELL, J., sporting of sugar-cane, [11].
“CALONGOS,” a Columbian breed of cattle, [3].
CALVER, Mr., on a seedling peach producing both peaches and nectarines, [10].
CALYX, segments of the, converted into carpels, [27].
CAMEL, its dislike to crossing water, [6].
Camellia, bud-variations in, [11];
—recognition of varieties of, [22];
—variety in, hardiness of, [24].
CAMERON, D, on the cultivation of Alpine plants, [18].
CAMERONN, Baron, value of English blood in racehorses, [12].
Campanula medium, [20].
CANARY-BIRD, [8];
—conditions of inheritance in, [12];
—hybrids of, [13];
—period of perfect plumage in, [14];
—diminished fertility of, [18];
—standard of perfection in, [20];
—analogous variation in, [26].
CANCER, heredity of, [12], [14].
CANFIELD, Dr., on horses with curled hair, [2];
—on feral horses in North America, [2].
CANINE teeth, development of the, in mares, [24].
Canis alopex, [1].
Canis antarcticus, [1].
Canis argentatus, [18].
Canis aureus, [1].
Canis cancrivorus, domesticated and crossed in Guiana, [1].
Canis cinereo-variegatus, [1].
Canis fulvus, [1].
Canis ingæ, the naked Peruvian dog, [1].
Canis latrans, [1];
—resemblance of, to the Hare Indian dog, [1];
—one of the original stocks, [1].
Canis lupaster, [1].
Canis lupus, var. occidentalis, resemblance of, to North American dogs, [1];
—crossed with dogs, [1];
—one of the original stocks, [1].
Canis mesomelas, [1] (2).
Canis primævus, tamed by Mr. Hodgson, [1].
Canis sabbar, [1].
Canis simensis, possible original of greyhounds, [1].
Canis thaleb, [1].
Canis variegatus, [1].
CANNING, A. S. G., the japanned peacock, [8].
CANTERBURY Bell, doubled by selection, [20].
CAPE of Good Hope, different kinds of cattle at the, [3];
—no useful plants derived from the, [9].
CAPERCAILZIE, breeding in captivity, [18].
Capra ægagrus and C. falconeri, probable parents of domestic goat, [3].
CAPSICUM, [10].
CARDAN, on a variety of the walnut, [10];
—on grafted walnuts, [22].
CARDOON, [13].
Carex rigida, local sterility of the, [18].
CARLIER, early selection of sheep, [20].
CARLISLE, Sir A., inheritance of peculiarities, [12] (2).
—of polydactylism, [12].
“CARME” pigeon, [5].
CARNATION, bud-variation in, [11];
—variability of, [10];
—striped, produced by crossing red and white, [12];
—effect of conditions of life on the, [23].
CARNIVORA, general fertility of, in captivity, [18].
CAROLINE Archipelago, cats of, [1].
CARP, [21].
CARPELS, variation of, in cultivated Cucurbitaceæ, [10].
CARPENTER, W. B., regeneration of bone, [24];
—number of eggs in an Ascaris, [27].
Carpinus betulus, [27].
Carpophaga oceanica, [28].
CARR, Mr., effect of changed conditions, [17].
CARRIER pigeon, [5];
—English, [5];
—figured, [5];
—skull figured, [5];
—history of the, [6];
—Persian, [5];
—Bussorah, [5];
—Bagadotten, skull figured, [5];
—lower jaw figured, [5].
CARRIÈRE, origin of radish, [9];
—intermediate form between the almond and the peach, [10];
—glands of peach-leaves, [10];
—bud-variation in the vine, [11];
—bud-variation in the rose, [11];
—inheritance in purple-leaved trees, [12];
—on variation, [11] (3);
—grafts of Aria vestita upon thorns, [11];
—variability of hybrids of Erythrina, [22].
CARROT, wild, effects of cultivation on the, [9];
—reversion in the, [13];
—run wild, [13];
—increased fertility of cultivated, [16];
—experiments on the, [23];
—acclimatisation of the, in India, [24].
Carthamus, abortion of the pappus in, [24].
CARTIER, cultivation of native plants in Canada, [9].
CARYOPHYLLACEÆ, frequency of contabescence in the, [18].
CASPARY, bud-variation in the moss-rose, [11];
—on the ovules and pollen of Cytisus, [11];
—crossing of Cytisus purpureus and C. laburnum, [11];
—trifacial orange, [11];
—differently-coloured flowers in the wild Viola lutea, [11];
—sterility of the horse-radish, [18].
CASTELNAU, on Brazilian cattle, [3].
CASTRATION, assumption of female characters caused by, [13] (2).
Casuarius bennettii, [18].
CAT, domestic, [1];
—early domestication and probable origin of the, [1] (2);
—intercrossing of, with wild species, [1] (2);
—variations of, [1];
—feral, [1], [13];
—anomalous, [1];
—polydactylism in, [12];
—black, indications of stripes in young, [13];
—tortoiseshell, [14];
—effects of crossing in, [15];
—fertility of, [16];
—difficulty of selection in, [21] (2);
—length of intestines in, [24];
—white with blue eyes, deafness of, [25];
—with tufted ears, [26].
CATARACT, hereditary, [12], [14].
CATERPILLARS, effect of changed food on, [23].
Catleya leopoldii, [11].
CATLIN, G., colour of feral horses in North America, [2].
CATON, Judge, wild turkey, [16].
CATTLE, European, their probable origin from three original species, [3];
—humped, or zebus, [3];
—intercrossing of, [3] (3);
—wild, of Chillingham, Hamilton, Chartley, Burton Constable, and Gisburne, [1], [17];
—colour of feral, [3], [20];
—British breeds of, [3] (2);
—South African breeds of, [3];
—South American breeds of, [3], [20];
—Niata, [3] (2), [20] (2), [25];
—effects of food and climate on, [3];
—effects of selection on, [3] (2);
—Dutch-buttocked, [12];
—hornless, production of horns in, [25];
—reversion in, when crossed, [13];
—wildness of hybrid, [13];
—short-horned, prepotency of, [14];
—wild, influence of crossing and segregation on, [15];
—crosses of, [15], [16], [17];
—of Falkland Islands, [16];
—mutual fertility of all varieties of, [16];
—effects of interbreeding on, [17] (2);
—shorthorn, sterility of, [17];
—effects of careful selection on, [20] (2);
—naked, of Columbia, [20];
—crossed with wild banteng in Java, [20];
—with reversed hair in Banda Oriental, [20];
—selection of trifling characters in, [20];
—fashion in, [20];
—similarity of best races of, [21];
—unconscious selection in, [20];
—effects of natural selection on anomalous breeds of, [21] (2);
—light-coloured, attacked by flies, [21], [25];
—Jersey, rapid improvement of, [21];
—effects of disuse of parts in, [24];
—rudimentary horns in, [24];
—supposed influence of humidity on the hair of, [25];
—white spots of, liable to disease, [25];
—supposed analogous variation in, [26];
—displacement of long-horned by short-horned, [28].
CAULIFLOWER, [9];
—free-seeding of, in India, [21];
—rudimentary flowers in, [24].
CAVALIER pigeon, [15].
Cavia aperea, [18].
CAY (Cebus azaræ), sterility of, in confinement, [18].
Cebus azaræ, [18].
Cecidomyia, larval development of, [23], [27] (2);
—and Misocampus, [Introduction].
CEDARS of Lebanon and Atlas, [10].
CELERY, turnip-rooted, [9];
—run wild, [13].
CELL-THEORY, [27].
Celosia cristata, [10].
CELSUS, on the selection of seed-corn, [9], [20].
CELTS, early cultivation of the cabbage by the, [9];
—selection of cattle and horses by the, [20].
Cenchrus, seeds of a, used as food, [9].
Centaurea cyanus, bud-variation in, [11].
CEPHALOPODA, spermatophores of, [27].
Cerasus padus, yellow-fruited, [12].
Cercoleptes, sterility of, in captivity, [18].
Cercopithecus, breeding of a species of, in captivity, [18].
CEREALS, [9] (2);
—of the Neolithic period in Switzerland, [9];
—adaptation of, to soils, [24].
Cereus, [13].
Cereus speciosissimus and phyllanthus, reversion in hybrids of, [11].
Cervus canadensis, [18].
Cervus dama, [17].
CETACEA, correlation of dermal system and teeth in the, [25].
CEYLON, cats of, [1];
—pigeon-fancying in, [6].
CHAMISSO, on seeding bread-fruit, [18].
CHANNEL Islands, breeds of cattle in, [3].
CHAPMAN, Professor, peach-trees producing nectarines, [10].
CHAPUIS, F., sexual peculiarities in pigeons, [5];
—effect produced by first male upon the subsequent progeny of the female, [11];
—sterility of the union of some pigeons, [18].
CHARACTERS, fixity of, [21];
—latent, [13], [27] (2);
—continued divergence of, [21];
—antagonistic, [27].
CHARDIN, abundance of pigeons in Persia, [6].
CHARLEMAGNE, orders as to the selection of stallions, [20].
CHARTLEY, wild cattle of, [3].
CHATÉ, reversion of the upper seeds in the pods of stocks, [26].
CHAUNDY, Mr., crossed varieties of cabbage, [17].
CHEETAH, general sterility of, in captivity, [18].
Cheiranthus cheiri, [11].
CHERRIES, [10] (2);
—bud-variation in, [11];
—white Tartarian, [21];
—variety of, with curled petals, [21];
—period of vegetation of, changed by forcing, [24].
CHEVREUL, on crossing fruit-trees, [17].
CHICKENS, differences in characters of, [7] (2);
—white, liable to gapes, [21], [25].
CHIGOE, [23].
CHILE, sheep of, [3].
CHILLINGHAM cattle, identical with Bos primigenius, [3];
—characters of, [3].
CHILOE, half-castes of, [13].
CHINA, cats of, with drooping ears, [1];
—horses of, [2];
—striped ponies of, [2];
—asses of, [2];
—notice of rabbits in, by Confucius, [4];
—breeds of pigeons reared in, [6];
—breeds of fowls of, in fifteenth century, [7] (2).
CHINCHILLA, fertility of, in captivity, [18].
CHINESE, selection practised by the, [20];
—preference of the, for hornless rams, [20];
—recognition of the value of native breeds by the, [24].
CHINESE, or Himalayan rabbit, [4].
“CHIVOS,” a breed of cattle in Paraguay, [3].
CHOUX-RAVES, [9].
CHRIST, H., on the plants of the Swiss Lake-dwellings, [9] (2);
—intermediate forms between Pinus sylvestris and montana, [10].
CHRYSANTHEMUM, [11].
Chrysotis festiva, [23].
CINERARIA, effects of selection on the, [20].
CIRCASSIA, horses of, [16].
CIRCUMCISION, [12].
CIRRIPEDES, metagenesis in, [27].
Cistus, intercrossing and hybrids of, [10], [12], [17].
CITRONS, [10] (2).
“Citrus aurantium fructu variabili,” [10] Citrus decumana, [10].
Citrus lemonum, [10].
Citrus medica, [10] (2).
CLAPHAM, A., bud-variation in the hawthorn, [11].
“CLAQUANT” (pigeons), [5].
“CLAQUERS” (pigeons), [5].
CLARK, G., on the wild dogs of Juan de Nova, [1];
—on striped Burmese and Javanese ponies, [2];
—breeds of goats imported into the Mauritius, [3];
—variations in the mammæ of goats, [3];
—bilobed scrotum of Muscat goat, [3].
CLARK, H. J., on fission and gemmation, [27].
CLARKE, R. T., intercrossing of strawberries, [10].
CLARKE, T., hybridisation of stocks, [11], [15].
CLARKSON, Mr., prize-cultivation of the gooseberry, [10].
CLASSIFICATION, explained by the theory of natural selection, [Introduction].
CLEFT palate, inheritance of, [12].
CLEMENTE, on wild vines in Spain, [10].
CLERMONT-TONNERRE, on the St. Valéry apple, [11].
CLIMATE, effect of, upon breeds of dogs, [1];
—on horses, [2] (2);
—on cattle, [3] (2);
—on the fleece of sheep, [3] (2);
—on seeds of wheat, [9];
—on cultivated cabbages, [9];
—adaptation of maize to, [9].
CLIMATE and pasture, adaptation of breeds of sheep to, [3] (2).
CLIMATE and soil, effects of, upon strawberries, [10].
CLINE, Mr., on the skull in horned and hornless rams, [25].
CLOS, on sterility in Ranunculus ficaria, [18].
CLOTZSCH, hybrids of various trees, [17].
CLOVER, pelorism in, [26].
COATE, Mr., on interbreeding pigs, [17].
COCCUS of apple-trees, [21].
COCHIN fowls, [7] (5);
—occipital foramen of, figured, [7];
—section of skull of, figured, [7];
—cervical vertebra of, figured, [7].
COCHINEAL, persistence of, [21];
—preference of, for a particular cactus, [23].
Cochlearia armoracia, [18].
COCK, game, natural selection in, [21];
—spur of, grafted on the comb, [24];
—spur of, inserted into the ear of an ox, [27];
—effect of castration upon the, [13].
COCK’S-COMB, varieties of the, [10].
COCOONS of silkworms, variations in, [8].
CODFISH, bulldog, [3];
—number of eggs in the, [27].
Coelogenys paca, [18].
COLIN, prepotency of the ass over the horse, [14];
—on cross-breeding, [15];
—on change of diet, [24].
COLLINSON, PETER, peach-tree producing a nectarine, [10].
COLORATION in pigeons, an evidence of unity of descent, [6].
COLOUR, correlation of, in dogs, [1];
—persistence of, in horses, [2];
—inheritance and diversity of, in horses, [2];
—variations of, in the ass, [5];
—of wild or feral cattle, [5];
—transmission of, in rabbits, [4];
—peculiarities of, in Himalayan rabbits, [4];
—influence of, [21];
—correlation of, in head and limbs, [25];
—correlated with constitutional peculiarities, [25].
COLOUR and odour, correlation of, [25].
COLOUR-BLINDNESS, hereditary, [12];
—more common in men than in women, [14] (2);
—associated with inability to distinguish musical sounds, [25].
COLOURS, sometimes not blended by crossing, [15].
Columba affinis, Blyth, a variety of C. livia, [6].
Columba amaliæ, Brehm, a variety of C. livia, [6].
Columba guinea, [6].
Columba gymnocyclus, Gray, a form of C. livia, [6].
Columba gymnophthalmos, hybrids of, with C. œnas, [6];
—with C. maculosa, [6].
Columba intermedia, Strickland, a variety of C. livia, [6].
Columba leucocephala, [18].
Columba leuconota, [6] (2).
Columba littoralis, [6].
Columba livia, [13] (2);
—the parent of domestic breeds of pigeons, [6];
—measurements of, [5];
—figured, [5];
—skull figured, [5];
—lower jaw figured, [5];
—scapula figured, [5].
Columba luctuosa, [6].
Columba migratoria and leucocephala, diminished fertility of, in captivity, [18].
Columba œnas, [6];
—crossed with common pigeon and C. gymnophthalmos, [6].
Columba palumbus, [6], [26].
Columba rupestris, [6] (3).
Columba schimperi, [6].
Columba torquatrix, [26].
Columba turricola, [6].
COLUMBIA, cattle of, [6]. COLUMBINE, double, [10], [25].
COLUMBUS, on West Indian dogs, [1].
COLUMELLA, on Italian shepherd dogs, [1];
—on domestic fowls, [7] (2), [20], [28];
—on the keeping of ducks, [8];
—on the selection of seed-corn, [9];
—on the benefits of change of soil to plants, [18];
—on the value of native breeds, [24].
COLZA, [9].
COMB, in fowls, variations of, [7];
—sometimes rudimentary, [24].
COMPENSATION, law of, [7].
COMPENSATION of growth, [26].
COMPLEXION, connection of, with constitution, [25].
COMPOSITÆ, double flowers of, [10], [18], [24].
CONCEPTION, earlier in Alderney and Zetland cows than in other breeds, [3].
CONDITIONS of life, changed, effect of, [28];
—on horses, [2];
—upon variation in pigeons, [6];
—upon wheat, [9];
—upon trees, [10];
—in producing bud-variation, [11];
—advantages of, [18];
—sterility caused by, [18];
—conducive to variability, [22];
—accumulative action of, [22];
—direct action of, [23].
CONDOR, breeding in captivity, [18].
CONFINEMENT, effect of, upon the cock, [17].
CONFUCIUS, on the breeding of rabbits in China, [4].
CONOLLY, Mr., on Angora goats, [25].
CONSTITUTIONAL differences in sheep, [3];
—in varieties of apples, [10];
—in pelargoniums, [10];
—in dahlias, [10].
CONSTITUTIONAL peculiarities in strawberries, [10];
—in roses, [10].
CONSUMPTION, hereditary, [12];
—period of appearance of, [14];
—correlated with complexion, [25].
CONTABESCENCE, [18] (2).
Convolvulus batatas, [18], [24].
Convolvulus tricolor, bud-variation in, [11].
COOPER, Mr., improvement of vegetables by selection, [20].
COOPER, WHITE, hereditary peculiarities of vision, [12];
—association of affections of the eyes with those of other systems, [25].
CORALS, bud-variation in, [11];
—non-diffusion of cell-gemmules in, [27].
CORBIÉ, See Boitard.
CORDEMOZ, Dr., seedless plants, [18].
CORNEA, opacity of, inherited, [12].
Cornus mascula, yellow-fruited, [12].
CORRELATION, [25];
—of neighbouring parts, [25];
—of change in the whole body, and in some of its parts, [25];
—of homologous parts, [25];
—inexplicable, [25], [26], [27];
—commingling of, with the effects of other agencies, [25].
CORRELATION of skull and limbs in swine, [3];
—of tusks and bristles in swine, [3];
—of multiplicity of horns and coarseness of wool in sheep, [3];
—of beak and feet in pigeons, [5] (2);
—between nestling down and colour of plumage in pigeons, [6];
—of changes in silkworms, [8];
—in plants, [20];
—in maize, [9];
—in pigeons, [5];
—in fowls, [7].
CORRESPONDING periods, inheritance at, [14].
CORRIENTES, dwarf cattle of, [3].
CORRINGHAM, Mr., influence of selection on pigs, [20].
CORSICA, ponies of, [2].
“CORTBECK” (pigeon) of Aldrovandi, [6].
Corvus corone, and C. cornix, hybrids of, [15].
Corydalis, flower of, [26].
Corydalis cava, [17] (2).
Corydalis solida, sterile when peloric, [18].
Corydalis tuberosa, peloric by reversion, [13].
Corylus avellana, [10].
COSTA, A., on shells transferred from England to the Mediterranean, [23].
COUES, Dr. E., on a monstrous chicken, [27].
COWPER, Mr. WHITE, defective development of the dental system, [25].
“COUVE TRONCHUDA,” [9] COW, inheritance of loss of one horn in the, [12];
—amount of milk furnished by the, [24];
—development of six mammæ in, [24].
COWSLIP, [12].
CRACIDÆ, sterility of the, in captivity, [18].
CRANES, fertility of, in captivity, [18].
Cratægus oxyacantha, [10], [11], [21], [22], [12].
Cratægus monogyna, [10].
Cratægus sibirica, [10].
CRAWFURD, J., Malasian cats, [1];
—horses of the Malay Archipelago, [2];
—horses of Japan, [2];
—occurrence of stripes in young wild pigs of Malacca, [3];
—on a Burmese hairy family with deficient teeth, [14], [25];
—Japanese origin of the bantam, [7];
—game fowls of the Philippine Islands, [22];
—hybrids of Gallus varius and domestic fowl, [7];
—domestication of Gallus bankiva, [7];
—feral fowls in the Pellew Islands, [7];
—history of the fowl, [7];
—history of the domestic duck, [8];
—domestication of the goose, [8];
—cultivated plants of New Zealand, [9];
—breeding of tame elephants in Ava, [18];
—sterility of Goura coronata in confinement, [18];
—geese of the Philippine Islands, [18].
CREEPERS, a breed of fowls, [7].
CRESTED fowl, [7];
—figured, [7].
“CRÈVE-CŒUR,” a French sub-breed of fowls, [7].
CRISP, Dr., on the brains of the hare and rabbit, [4].
CROCKER, C. W., singular form of Begonia frigida, [10], [18];
—sterility in Ranunculus ficaria, [18].
CROCUS, [18].
CROSS-BREEDING, permanent effect of, on the female, [11].
CROSSING, [15], [16], [17], [19];
—a cause of uniformity, [15];
—occurs in all organised beings, [15];
—some characters not blended by, [15], [19];
—modifications and new races produced by, [15];
—causes which check, [16];
—domestication and cultivation favourable to, [16], [19];
—beneficial effects of, [17], [19];
—necessary in some plants, [17], [19];
—summary of subject of, [17];
—of dogs with wolves in North America, [1] (2);
—with Canis cancrivorus in Guiana, [1];
—of dog with wolf, described by Pliny and others, [1];
—characters furnished by, brought out by reversion in the progeny, [13];
—a direct cause of reversion, [13] (2);
—a cause of variability, [22].
CRUSTACEA, macrourous, differences in the development of the, [27].
CRUSTACEAN with an antenna-like development of the eye-peduncle, [27].
CRYPTOGAMIC plants, bud-variation in, [11].
CUBA, wild dogs of, [1].
“CUCKOO,” sub-breeds of fowls, [7].
CUCUMBER, variation in number of carpels of, [10];
—supposed crossing of varieties of the, [11].
Cucumis momordica, [10].
Cucumis sativa, [10].
Cucurbita, dwarf, correlation of leaves in, [25].
Cucurbita maxima, [10] (2).
Cucurbita moschata, [10] (2).
Cucurbita pepo [10];
—varieties of, [10];
—relation in size and number of fruit of, [26].
CUCURBITACEÆ, [10];
—supposed crossing of, [11];
—Naudin’s observations on hybrids of, [18];
—acclimatisation of, [24].
“CULBUTANTS” (pigeons), [5].
CULTIVATION of plants, origin of, among savages, [9] (2);
—fertility increased by, [16].
CUNIER, on hereditary night-blindness, [12].
CUPPLES, Mr., pairing of deer-hounds, [17].
CURRANTS, of Tierra del Fuego, [9];
—bud-variation in, [11].
CURTIS, Mr., bud-variation in the rose, [11].
CUVIER, on the gestation of the wolf, [1];
—the odour of the jackal, an obstacle to domestication, [1];
—differences of the skull in dogs, [1];
—external characters of dogs, [1];
—elongation of the intestines in domestic pigs, [3], [24];
—fertility of the hook-billed duck, [8];
—hybrid of ass and zebra, [13];
—breeding of animals in the Jardin des Plantes, [18];
—sterility of predaceous birds in captivity, [18];
—facility of hybridisation in confinement, [18].
CYANOSIS, affection of fingers in, [25].
CYCLAMEN, bud-variation in, [11].
Cynara cardunculus, [13].
Cynips fecundatrix, [23].
Cynocephalus hamadryas, [18].
Cyprinus auratus, [8].
Cyrtanthus, [17].
Cyrtopodium, [17].
Cytisus adami, its bud-variation, [11];
—seedlings from, [11];
—different views of its origin, [11];
—experiments in crossing C. purpureus and laburnum to produce, [11];
—its production by M. Adam, [11];
—discussion of origin of, [11].
Cytisus alpino-laburnum, ovules and pollen of, [11];
—origin of, [11].
Cytisus alpinus, [11].
Cytisus laburnum, [11] (3).
Cytisus purpureo-elongatus, ovules and pollen of, [11];
—production of, [11].
Cytisus purpureus, [11].
DAHLBOHM, effects of food on hymenoptera, [23].
DAHLIA, [10];
—bud-variation by tubers in the, [11];
—improvement of, by selection, [20];
—steps in cultivation of, [22];
—effect of conditions of life on, [23];
—correlation of form and colour in, [25].
DAISY, hen-and-chicken, [10];
—Swan River, [22].
DALBRET, varieties of wheat, [9].
DALIBERT, changes in the odours of plants, [23].
DALLY, Dr., on consanguineous marriages, [17].
DALTONISM, hereditary, [12].
DAMARAS, cattle of, [3], [20] (2).
DAMSON, [10].
DANDOLO, Count, on silkworms, [8].
DANIELL, fertility of English dogs in Sierra Leone, [18].
DANISH Middens, remains of dogs in, [1].
DAPPLING in horses, asses, and hybrids, [2].
DARESTE, C., on the skull of the Polish fowl, [7];
—causes of variability, [22];
—on the production of monstrous chickens, [23];
—co-existence of anomalies, [25];
—production of double monsters, [26].
DARVILL, Mr., heredity of good qualities in horses, [12].
DARWIN, C., on Lepus magellanicus, [4];
—on the wild potato, [9];
—dimorphism in the polyanthus and primrose, [12].
DARWIN, Dr., improvement of vegetables by selection, [20].
DARWIN, Sir F., wildness of crossed pigs, [13].
DARWIN, G., consanguineous marriages, [17].
D’ASSO, monogynous condition of the hawthorn in Spain, [10].
Dasyprocta aguti, [18].
DATE-PALM, varieties of the, [22].
Datura, [13];
—variability in, [22].
Datura lævis and stramonium, reversion in hybrids of, [11].
Datura stramonium, [14].
DAUBENTON, variations in the number of mammæ in dogs, [1];
—proportions of intestines in wild and domestic cats, [1], [24].
DAUDIN, on white rabbits, [21].
DAVY, Dr., on sheep in the West Indies, [3].
DAWKINS, W. BOYD, history of the dog, [1];
—origin of cattle, [3];
—early domestication of Bos longifrons in Britain, [3].
DEAF-MUTES, non-heredity in, [12].
DEAFNESS, inheritance of, [14].
DEAN, potato-grafting, [11].
DEBY, wild hybrids of common and musk ducks, [13].
DE CANDOLLE, ALPH., number and origin of cultivated plants, [9] (2), [10];
—regions which have furnished no useful plants, [9];
—wild wheat, [9] (2);
—wild rye and oats, [9];
—antiquity of varieties of wheat, [9];
—apparent inefficacy of selection in wheat, [9];
—origin and cultivation of maize, [9], [25];
—colours of seeds of maize, [9];
—varieties and origin of the cabbage, [9] (2);
—origin of the garden-pea, [9];
—on the vine, [10], [24];
—cultivated species of the orange group, [10];
—Chinese origin of the peach, [10];
—on the peach and nectarine, [10] (2);
—varieties of the peach, [10];
—origin of the apricot, [10];
—origin and varieties of the plum, [10];
—origin of the cherry, [10];
—varieties of the gooseberry, [10];
—selection practised with forest-trees, [10];
—wild fastigiate oak, [10];
—dark-leaved varieties of trees, [10];
—conversion of stamens into pistils in the poppy, [10];
—variegated foliage, [10];
—heredity of white hyacinths, [10], [12];
—changes in oaks dependent on age, [11];
—inheritance of anomalous characters, [12];
—variation of plants in their native countries, [22];
—deciduous bushes becoming evergreen in hot climates, [24];
—antiquity of races of plants, [28].
DE CANDOLLE, P., non-variability of monotypic genera, [22];
—relative development of root and seed in Raphanus sativus, [26].
DECAISNE, on the cultivation of the wild carrot, [9];
—varieties of the pear, [10];
—intercrossing of strawberries, [10];
—fruit of the apple, [11];
—sterility of Lysimachia nummularia, [18];
—tender variety of the peach, [24].
DEER, assumption of horns by female, [13];
—imperfect development of horns in a, on a voyage, [18].
DEER, fallow, [16].
DEERHOUND, Scotch, difference in size of the sexes of, [14];
—deterioration of, [17].
DEGENERATION of high-bred races, under neglect, [21].
DE JONGHE, J., on strawberries, [10];
—soft-barked pears, [21];
—on accumulative variation, [22];
—resistance of blossoms to frost, [24].
DELAMER, E. S., on rabbits, [4] (2).
Delphinium ajacis, [12].
Delphinium consolida, [12] (2).
DELPINO on Pangenesis, [27] (2).
Dendrocygna viduata, [18].
DENNY, H., lice of Aperea, [18].
DENTITION, variations of, in the horse, [2].
DEODAR, [10].
DESMAREST, distribution of white on dogs, [1];
—cat from the Cape of Good Hope, [1];
—cats of Madagascar, [1];
—occurrence of striped young in Turkish pigs, [3];
—French breeds of cattle, [3];
—horns of goats, [3];
—on hornless goats, [24].
DESPORTES, number of varieties of roses, [10].
DEVAY, Dr., singular case of albinism, [12];
—on the marriage of cousins, [17];
—on the effects of close interbreeding, [22].
DEVELOPMENT and metamorphosis, [27] (2).
DEVELOPMENT, arrests of, [24].
DEVELOPMENT, embryonic, [27].
D’HERVEY-SAINT-DENYS, L., on the Yami, or imperial race of the Chinese, [20].
DHOLE, fertility of the, in captivity, [18].
DIABETES, occurrence of, in three brothers, [12].
Dianthus, contabescent plants of, [18] (2);
—hybrid varieties of, [22].
Dianthus armeria and deltoides, hybrids of, [15].
Dianthus barbatus, [11].
Dianthus caryophyllus, [11].
Dianthus japonicus, contabescence of female organs in, [18].
Diapheromera femorata, [27].
DICHOGAMOUS plants, [15].
DICKSON, Mr., on “running” in carnations, [11];
—on the colours of tulips, [11].
Dicotyles torquatus and labiatus, [18].
DIEFFENBACH, dog of New Zealand, [1];
—feral cats in New Zealand, [1];
—polydactylism in Polynesia, [12].
Dielytra, [13].
DIET, change of, [24] (2).
Digitalis, properties of, affected by culture, [23].
DIGITS, supernumerary, [12];
—analogy of, with embryonic conditions, [13];
—fusion of, [26].
DIMORPHIC plants, [17];
—conditions of reproduction in, [19].
DIMORPHISM, reciprocal, [15].
DINGO, [1];
—variation of, in colour [1];
—half-bred, attempting to burrow [1];
—attraction of foxes by a female, [1];
—variations of, in confinement, [22].
DIOECIOUSNESS of strawberries, [10].
DISEASES, inheritance of, [12] (2);
—inherited at corresponding periods of life, [14];
—peculiar to localities and climates, [23];
—obscure correlations in, [25] (2);
—affecting certain parts of the body, [27];
—occurring in alternate generations, [27].
DISTEMPER, fatal to white terriers, [21].
DISUSE and use of parts, effects of, [24], [26] (2), [28] (2);
—in the skeleton of rabbits, [4];
—in pigeons, [5];
—in fowls, [7];
—in ducks, [8];
—in the silk-moth, [8].
DIVERGENCE, influence of, in producing breeds of pigeons, [6].
DIXON, E. S., on the musk duck, [6];
—on feral ducks, [6];
—on feral pigeons in Norfolk Island, [6];
—crossing of pigeons, [6];
—origin of domestic fowls, [7];
—crossing of Gallus sonneratii and common fowl, [7];
—occurrence of white in the young chicks of black fowls, [7];
—Paduan fowl of Aldrovandi, [7];
—peculiarities of the eggs of fowls, [7];
—chickens, [7] (2);
—late development of the tail in Cochin cocks, [7];
—comb of lark-crested fowls, [7];
—development of webs in Polish fowls, [7];
—on the voice of fowls, [7];
—origin of the duck, [8];
—ducks kept by the Romans, [8];
—domestication of the goose, [8];
—gander frequently white, [8];
—breeds of turkeys, [8];
—incubatory instinct of mongrels of non-sitting races of fowls, [13];
—aversion of the dove-cot pigeon to pair with fancy birds, [16];
—fertility of the goose, [16];
—general sterility of the guans in captivity, [18];
—fertility of geese in captivity, [18];
—white pea-fowl, [25].
DOBELL, H., inheritance of anomalies of the extremities, [12];
—non-reversion to a malformation, [13].
DOBRIZHOFFER, abhorrence of incest by the Abipones, [17].
DOGS, origin of, [1];
—ancient breeds of, [1], [28];
—of Neolithic, Bronze and Iron periods in Europe, [1] (2), [28];
—resemblance of, to various species of Canidæ, [1];
—of North America compared with wolves, [1] (2);
—of the West Indies, South America, and Mexico, [1] (2);
—of Guiana, [1] (2);
—naked dogs of Paraguay and Peru, [1] (2);
—dumb, on Juan Fernandez, [1];
—of Juan de Nova, [1];
—of La Plata, [1];
—of Cuba, [1];
—of St. Domingo, [1];
—correlation of colour in, [1] (2);
—gestation of, [1] (2);
—hairless Turkish, [1], [21];
—inter-crossing of different breeds of, [1];
—characters of different breeds of, discussed, [1];
—degeneration of European, in warm climates, [1] (2), [23];
—liability to certain diseases in different breeds of, [1] (2);
—causes of differences of breeds discussed, [1];
—catching fish and crabs in New Guinea and Tierra del Fuego, [1];
—webbing of the feet in, [1];
—influence of selection in producing different breeds of, [1] (2);
—retention of original habits by, [6];
—inheritance of polydactylism in, [12];
—feral, [13];
—reversion in fourth generation of, [13];
—of the Pacific Islands, [15], [20], [27];
—mongrel, [15];
—comparative facility of crossing different breeds of, [16];
—fertility of, [16], [18];
—interbreeding of, [17];
—selection of, among the Greeks, [20] (2);
—among savages, [17] (2);
—unconscious selection of, [20] (2);
—valued by the Fuegians, [20] (2);
—climatal changes in hair of, [23];
—production of drooping ears in, [24];
—rejection of bones of game by, [24];
—inheritance of rudiments of limbs in, [24];
—development of fifth toe in, [24];
—hairless, deficiency of teeth in, [25];
—short-faced, teeth of, [26];
—probable analogous variation in, [26];
—extinction of breeds of, [28].
DOMBRAIN, H. H., on the auricula, [26].
DOMESTICATION, essential points in, [28] (2);
—favourable to crossing, [16], (2);
—fertility increased by, [16], [19].
DOMESTICATED animals, origin of, [18] (2);
—occasional sterility of, under changed conditions, [18] (2).
DONDERS, Dr., hereditary hypermetropia, [12].
DORKING fowl, [7] (2);
—furculum of, figured, [7].
DORMOUSE, [18].
DOUBLE flowers, [18] (4);
—produced by selection, [20].
DOUBLEDAY, H., cultivation of the filbert pine strawberry, [10].
DOUGLAS, J., crossing of white and black game-fowls, [15].
DOWNING, Mr., wild varieties of the hickory, [9];
—peaches and nectarines from seed, [10] (2);
—origin of the Boston nectarine, [10];
—American varieties of the peach, [10];
—North American apricot, [10];
—varieties of the plum, [10];
—origin and varieties of the cherry, [10] (2);
—“twin-cluster pippins,” [10];
—varieties of the apple, [10];
—on strawberries, [10] (2);
—fruit of the wild gooseberry, [10];
—effects of grafting upon the seed, [12];
—diseases of plum and peach tree, [21];
—injury done to stone fruit in America by the “weevil,” [21];
—grafts of the plum and peach, [22];
—wild varieties of pears, [22];
—varieties of fruit-trees suitable to different climates, [24].
DOWNING, Mr. J., sterility of shorthorns, [17].
Draba sylvestris [18].
DRAGON (pigeon), [5] (2).
“DRAIJER” (pigeon), [5].
DRINKING, effects of, in different climates, [23].
DROMEDARY, selection of, [20].
DRUCE, Mr., interbreeding, [17];
—value of cross breed of pigs, [17].
DU CHAILLU, fruit-trees in West Africa, [9].
DUCHESNE, on Fragaria vesca, [10] (2).
DUFOUR, LEON, on Cecidomyia and Misocampus, [Introduction].
DUCK, musk, retention of perching habit by the, [6];
—feral hybrid of, [6].
DUCK, penguin, hybrid of, with Egyptian goose, [14].
Duck, wild, difficulty of rearing, [21];
—effects of domestication on, [23].
DUCKS, breeds of, [8] (2);
—origin of, [8];
—history of, [8];
—wild, easily tamed, [8] (2);
—fertility of breeds of, when crossed, [8];
—with the plumage of Anas boschas, [8];
—Malayan penguin, identical in plumage with English, [8];
—characters of the breeds of, [8];
—eggs of, [8];
—effects of use and disuse in, [8], [24];
—feral, in Norfolk, [6];
—Aylesbury, inheritance of early hatching by, [12];
—reversion in, produced by crossing, [13];
—wildness of half-bred wild, [13];
—hybrids of, with the musk duck, [13] (2);
—assumption of male plumage by, [13];
—crossing of Labrador and penguin, [15];
—increased fertility of, by domestication, [16];
—general fertility of, in confinement, [18];
—increase of size of, by care in breeding, [20];
—change produced by domestication in, [22].
DUMÉRIL, AUG., breeding of Siredon in the branchiferous stage, [27].
DUN-COLOURED horses, origin of, [2].
DUREAU DE LA MALLE, feral pigs in Louisiana, [13];
—feral fowls in Africa, [13];
—bud-variation in the pear, [11];
—production of mules among the Romans, [16].
Dusicyon silvestris, [1].
DUTCH rabbit, [4].
DUTCH roller pigeon, [5].
DUTROCHET, pelorism in the laburnum, [26].
DUVAL, growth of pears in woods in France, [22].
DUVAL-JOUVE, on Leersia oryzoides, [15].
DUVERNOY, self-impotence in Lilium candidum, [17].
DZIERZON, variability in the characters and habits of bees, [8].
EARLE, Dr., on colour-blindness, [14], [25].
EARS, of fancy rabbits, [4];
—deficiency of, in breeds of rabbits, [4];
—rudimentary, in Chinese sheep, [24];
—drooping, [24];
—fusion of, [26].
EATON, J. M., on fancy pigeons, [5], (2);
—variability of characters in breeds of pigeons, [5];
—reversion of crossed pigeons to coloration of Columba livia, [6];
—on pigeon-fancying, [6] (3);
—on tumbler-pigeons, [6], [21];
—carrier-pigeon, [6];
—effects of interbreeding on pigeons, [17];
—properties of pigeons, [20];
—death of short-faced tumblers in the egg, [21];
—Archangel-pigeon, [21].
ECHINODERMATA, metagenesis in, [27].
Ectopistes, specific difference in number of tail-feathers in, [5].
Ectopistes migratorius, sterile hybrids of, with Turtur vulgaris, [6].
EDENTATA, correlation of dermal system and teeth in the, [25].
EDGEWORTH, Mr., use of grass-seeds as food in the Punjab, [9].
EDMONSTON, Dr., on the stomach in Larus argentatus and the raven, [24].
EDWARDS and Colin, on English wheat in France, [24].
EDWARDS, W. F., absorption of the minority in crossed races, [15].
EDWARDS, W. W., occurrence of stripes in a nearly thoroughbred horse, [2];
—in foals of racehorses, [2].
EGGS, of fowls, characters of, [7];
—variations of, in ducks, [8];
—of the silk-moth, [8].
EGYPT, ancient dogs of, [1] (2);
—ancient domestication of the pigeon in, [6];
—absence of the fowl in ancient, [7].
EGYPTIAN goose, hybrids of, with penguin duck, [8].
EHRENBERG, Prof., multiple origin of the dog, [1];
—dogs of Lower Egypt, [1];
—mummies of Felis maniculata, [1].
ELEMENTS of the body, functional independence of the, [27].
ELEPHANT, its sterility in captivity,[18].
ELK, Irish, correlations in the, [25] (2).
ELLIOT, Sir WALTER, on cats in India, [1];
—on striped horses, [2];
—Indian domestic and wild swine, [3];
—pigeons from Cairo and Constantinople, [5];
—fantail pigeons, [5];
—Lotan tumbler pigeons, [5];
—a pigeon uttering the sound “Yahu,” [5];
—Gallus bankiva in Pegu, [7].
ELLIS, Mr., varieties of cultivated plants in Tahiti, [22].
ELM, nearly evergreen Cornish variety of the, [10], [24];
—foliage-varieties of the, [10].
ELM, weeping, [10];
—not reproduced by seed, [12].
Emberiza passerina, [18].
EMBRYOS, similarity of, [1];
—fusion of, [26].
ENGEL, on Laurus sassafras, [23].
ENGLAND, domestication of Bos longifrons in, [3];
—selection of horses in, in mediæval times, [20];
—laws against the early slaughter of rams in, [20].
EPHEMERIDÆ, development of the, [27].
Epidendrum cinnabarinum, [11];
—and E. zebra, [17].
EPILEPSY, hereditary, [12], [14].
Equus burchellii, [2].
Equus quagga, [2].
Equus indicus, [1] (2).
Equus tæniopus, [2] (2), [13].
ERDT, disease of the white parts of cattle, [25].
ERICACEÆ, frequency of contabescence in the, [18].
ERICHTHONIUS, an improver of horses by selection, [20].
ERMAN, on the fat-tailed Kirghisian sheep, [3], [23];
—on the dogs of the Ostyaks, [20].
Erodium, [13].
Erythrina crista-galli and E. herbacea, hybrids of, [22].
Eschscholtzia californica, self-sterile in England, [17].
ESQUILANT, Mr., on the naked young of dun-coloured pigeons, [5].
ESQUIMAUX dogs, their resemblance to wolves, [1];
—selection of, [20].
ESQUIROL, on hereditary insanity, [2].
EUDES-DESLONGCHAMPS, on appendages under the jaw of pigs, [3].
Euonymus japonicus, [11].
Euphorbia maculata, [23].
EUROPEAN cultivated plants, still wild in Europe, [9].
EVANS, Mr., on the Lotan tumbler pigeon, [5].
EVELYN, pansies grown in his garden, [10].
EVEREST, R., on the Newfoundland dog in India, [1], [24];
—degeneration of setters in India, [1];
—Indian wild boars, [3].
EWES, hornless, [26].
EXTINCTION of domestic races, [6].
EYES, hereditary peculiarities of the, [12];
—loss of, causing microphthalmia in children, [12];
—modification of the structure of, by natural selection, [20] (2).
EYEBROWS, hereditary elongation of hairs in, [12].
EYELIDS, inherited peculiarities of the, [12].
EYTON, Mr., on gestation in the dog, [1];
—variability in number of vertebræ in the pig, [3];
—individual sterility, [18].
Faba vulgaris, [9].
FABRE, observations on Ægilops triticoides, [9].
Fagus sylvatica, [12].
FAIRWEATHER, Mr., production of double flowers from old seed, [18].
FAIVRE, on the Primula sinensis, [10], [25].
Falco albidus, resumption of young plumage by, in captivity, [18].
Falco ossifragus, [21].
Falco subbuteo, copulating in captivity, [18].
Falco tinnunculus, breeding in captivity, [18].
FALCONER, Dr., sterility of English bulldogs in India, [1];
—resemblance between Sivatherium and Niata cattle, [3];
—selection of the silkworm in India, [8];
—fastigiate apple-trees in Calcutta, [10];
—reproduction of a supernumerary thumb after amputation, [12];
—fertility of the dhole in captivity, [18];
—fertility of English dogs in India, [18];
—sterility of the tiger in captivity, [18];
—turkeys at Delhi, [18];
—on Indian cultivated plants, [18];
—Thibet mastiff and goat, [23].
FALCONS, sterility of, in captivity, [18].
FALKLAND Islands, horses of the, [2] (2);
—feral pigs of the, [3];
—feral cattle of the, [3] (2);
—feral rabbits of the, [4].
FALLOW deer, [16], [17].
FANTAIL pigeons, [5], [21];
—figured, [5];
—furculum of, figured, [5];
—history of, [6];
—absence of oil-gland in, [26].
FAROE Islands, pigeons of the, [6].
FASHION, influence of, in breeding, [21].
FASTIGIATE trees, [23], [26].
FAUNAS, geographical differences of, [1].
“FAVOURITE” bull, [14], [17].
FEATHERS, homologous variation in, [25].
FEET, of pigeons, individual differences of, [5];
—correlations of external characters in, [5].
FEET and beak, correlation of, in pigeons, [5].
FELIDÆ, fertility of, in captivity, [18].
Felis bubastes, [1].
Felis caffra, [1].
Felis caligulata, [1].
Felis chaus, [1].
Felis jubata, [18].
Felis lybica, [1].
Felis maniculata, [1].
Felis manul, [1].
Felis ornata, [1].
Felis sylvestris, [1].
Felis torquata, [1].
FEMALE, affected by male element, [27] (2).
FEMALE flowers, in male panicle of maize, [9].
FENN, Mr., grafting potatoes, [11].
FENNEL, Italian variety of, [9].
FERAL cats, [1];
—cattle, [3];
—rabbits, [4] (2);
—Guinea fowl, [8];
—animals and plants, reversion in, [13] (3).
FERGUSON, Mr., supposed plurality of origin of domestic fowls, [7];
—chickens of black game-fowls, [7];
—relative size of eggs of fowls, [7];
—yolk of eggs of game-fowls, [7];
—early pugnacity of game-cocks, [7];
—voice of the Malay fowl, [7];
—effects of interbreeding on fowls, [17];
—selection in Cochin-China fowls, [20];
—on fashion in poultry, [21].
FERNANDEZ, on Mexican dogs, [1].
FERNS, reproduction of abnormal forms of, by spores, [11];
—non-diffusion of cell-gemmules in, [27].
FERRETS, [16], [18], [20].
FERTILISATION, artificial, of the St. Valéry apple, [10] (2).
FERTILITY, various degrees of, in sheep, [3];
—unlimited mutual, of breeds of pigeons, [6];
—comparative, of mongrels and hybrids, [16] (2), [19];
—influence of nourishment on, [16];
—diminished by close interbreeding, [17], [19];
—reduced, of Chillingham wild cattle, [17];
—of domesticated varieties when crossed, [19].
Festuca, species of, propagated by bulblets, [18].
FILBERTS, spared by tomtits, [21].
FILIPPI, on the breeding of branchiferous tritons, [27].
FINCHES, general sterility of, in captivity, [18].
FINNIKIN (pigeon), [5].
FINNOCCHIO, [9].
FIR, Scotch, acclimatisation of, [24].
FISH, Mr., advantage of change of soil to plants, [18].
FISHES, regeneration of portions of fins of, [13];
—variability of, when kept in tanks, [22];
—marine, living in fresh water, [24];
—double monsters of, [26].
FISSION and gemmation, [27].
FITCH, Mr., persistency of a variety of the pea, [9].
FITTEST, survival of the, [1].
FITZINGER, origin of sheep, [3];
—African maned sheep, [3].
FITZPATRICK, Mr., potato-grafting, [11].
FIXEDNESS of character, conditions of, discussed, [14].
FLAX, found in the Swiss lake-dwellings, [9];
—climatal difference in products of, [23].
FLEECE, fineness of, in Austrian merinos, [20].
FLEISCHMANN, on German sheep crossed with merinos, [15].
“FLORENTINER-TAUBE,” [5] (2).
FLOUNDER, [1].
FLOURENS, crossing of wolf and dog, [1];
—prepotency of the jackal over the dog, [14];
—hybrids of the horse and ass, [14];
—breeding of monkeys in Europe, [18].
FLOWER-GARDEN, earliest known, in Europe, [20].
FLOWERS, capricious transmission of colour-varieties in, [12] (2);
—tendency to uniformity in striped, [14];
—scorching of, dependent on colour, [21];
—change in, caused by conditions of life, [23];
—rudimentary, [24];
—relative position of, to the axis, [26].
FŒTATION, abdominal, [24].
FOLEY, Mr., wild varieties of pears, [22].
FOLIAGE, inherited peculiarities of, [10];
—variegation of, [10];
—bud-variation in, [11].
FOOD, influence of, on the pig, [3];
—on cattle, [3];
—excess of, a cause of variability, [22].
FORBES, D., on Chilian sheep, [3];
—on the horses of Spain, Chili, and the Pampas, [2].
Formica rufa, [22].
FORTUNE, R., sterility of the sweet potato in China, [18];
—development of axillary bulbs in the yam, [18].
FOWL, common, breeds of, [7];
—supposed plurality of origin, [7];
—early history of, [7];
—causes of production of breeds of, [7];
—origin of, from Gallus bankiva, [7] (2);
—feral, notices of, [7] (2);
—reversion and analogous variation in, [7], [13] (2), [26] (2);
—“cuckoo” sub-breeds of, [7];
—history of, [7];
—structural characters of, [7];
—sexual peculiarities of, [7], [14];
—external differences of, [7];
—differences of breeds of, from G. bankiva, [7];
—osteological characters of, [7];
—effects of disuse of parts in, [7], [24];
—feral, [6], [13];
—polydactylism in, [12];
—fertility of, increased by domestication, [16], [18];
—sterility of, under certain conditions, [18];
—influence of selection on, [20] (3);
—evils of close interbreeding of, [17] (2);
—crossing of, [15];
—prepotency of transmission in, [14];
—rudimentary organs in, [24];
—crossing of non-sitting varieties of, [13] (2);
—homology of wing and leg feathers in, [25];
—hybrids of, with pheasants and Gallus sonneratii, [13];
—black-skinned, [20];
—black, preyed upon by the osprey in Ireland, [21];
—five-toed, mentioned by Columella, [28];
—rumpless, tailed chickens produced by, [13];
—Dorking, crosses of, [15];
—form of comb and colour of plumage in, [21];
—game, crossing of white and black, [15];
—five-spurred, [27];
—Spanish, liable to suffer from frost, [24];
—Polish, peculiarities of skull of, [25].
FOX, sterility of, in captivity, [18].
FOX, S. BEVAN, races of bees, [8].
FOX, W. DARWIN, gestation of the dog, [1];
—“Negro” cat, [1];
—reversion of sheep in colour, [13];
—period of gestation in the pig, [3];
—young of the Himalayan rabbit, [4];
—crossing of wild and domestic turkeys, [8];
—reversion in crossed musk ducks, [13];
—spontaneous segregation of varieties of geese, [16];
—effects of close interbreeding upon bloodhounds, [17];
—deafness of white cats with blue eyes, [25].
FOXHOUNDS, [1], [17].
Fragaria chiloensis, [10].
Fragaria collina, [10].
Fragaria dioica of Duchesne, [10].
Fragaria elatior, [10].
Fragaria grandiflora, [10].
Fragaria vesca, [10].
Fragaria virginiana, [10].
Fraxinus excelsior, [10], [11], [12].
Fraxinus lentiscifolia, [12].
FRIESLAND cattle, probably descended from Bos primigenius, [3].
FRILLBACK pigeon, [5];
—Indian, [5].
Fringilla ciris, [18].
Fringilla spinus, [18].
FRIZZLED fowls, [7];
—horses, [2].
FROG, polydactylism in the, [12].
FRUIT, seedless, [18].
FRUIT-TREES, varieties of, occurring wild, [9].
FRY, Mr., on fertile hybrid cats, [1];
—on feral fowls in Ascension, [7].
FUCHSIAS, origin of, [10];
—bud-variation in,[11].
Fuchsia coccinea and fulgens, twin seed produced by crossing, [11].
FUEGIANS, their superstition about killing young water-fowl, [9];
—selection of dogs by the, [20];
—their comparative estimation of dogs and old women, [20];
—their power of distant vision, [20].
FUNGI, parasitic, [23] (2).
FÜRBRINGER, Dr., on nails of Saurians, [27].
FURCULUM, characters and variations of the, in pigeons, [5];
—alteration of, by disuse, in pigeons, [5];
—characters of, in fowls, [7].
FUSION of homologous parts, [27].
GAIT, inheritance of peculiarities of, [12].
GALAPAGOS Archipelago, its peculiar fauna and flora, [Introduction]
Galeobdolon luteum, pelorism in, [13], [26].
GALLS, [13] (2).
GALL-GNATS, [23].
GALL-LIKE excrescences not inherited, [13].
GALLINACEOUS birds, restricted range of large, [7];
—general fertility of, in captivity, [18].
Gallinula chloropus, [5].
Gallinula nesiotis, [8].
GALLESIO, species of oranges, [10];
—hybridisation of oranges, [10];
—persistency of races in the peach, [10];
—supposed specific distinctions of peach and nectarine[10];
—bizzarria orange, [11];
—crossing of red and white carnations, [11];
—crossing of the orange and lemon, [11], [27];
—effect of foreign pollen on maize, [4];
—spontaneous crossing of oranges, [15];
—monstrosities a cause of sterility in plants, [18];
—seeding of ordinarily seedless fruits, [18];
—sterility of the sugar-cane, [18];
—tendency of male flowers to become double, [18];
—effects of selection in enlarging fruit, etc., [20];
—variation of the orange-tree in North Italy, [22];
—naturalisation of the orange in Italy, [24].
Gallus æneus, a hybrid of G. varius and the domestic fowl, [7].
Gallus bankiva, probable original of domestic fowls, [7] (3);
—game-fowl, nearest to, [7];
—crossed with G. sonneratii, [7];
—its character and habits, [7], [16];
—differences of various breeds of fowls from, [7];
—occipital foramen of, figured, [7];
—skull of, figured, [7];
—cervical vertebra of, figured, [7];
—furculum of, figured, [7];
—reversion to, in crossed fowls, [13] (2);
—hybrid of, with G. varius, [7], [13];
—number of eggs of, [16].
Gallus ferrugineus, [7].
Gallus furcatus, [7].
Gallus giganteus, [7].
Gallus sonneratii, characters and habits of, [7];
—hybrids of, [7], [13]
Gallus stanleyi, hybrids of, [7].
Gallus temminckii, probably a hybrid, [7].
Gallus varius, characters and habits of, [7];
—hybrids and probable hybrids of, [7].
GALTON, Mr., fondness of savages for taming animals, [1];
—cattle of Benguela, [3];
—on hereditary talent, [12];
—on Pangenesis, [27].
GAMBIER, Lord, his early cultivation of the pansy, [10].
GAME-FOWL, [7] (2).
GAPES, [21].
GARCILAZO DE LA VEGA, annual hunts of the Peruvian Incas, [20].
GARNETT, Mr., migratory propensities of hybrid ducks, [13].
GARROD, Dr., on hereditary gout, [12].
GÄRTNER, on the sterility of hybrids, [6], [16], [19];
—acquired sterility of varieties of plants when crossed, [10];
—sterility in transplanted plants, and in the lilac in Germany, [18];
—mutual sterility of blue and red flowers of the pimpernel, [19];
—supposed rules of transmission in crossing plants, [14];
—on crossing plants, [15], [17] (3);
—on repeated crossing, [22];
—absorption of one species by another, when crossed, [15];
—crossing of varieties of the pea, [11];
—crossing maize, [16];
—crossing of species of Verbascum, [15], [16];
—reversion in hybrids, [13] (3);
—of Cereus, [11];
—of Tropæolum majus and minus, [11];
—variability of hybrids, [22];
—variable hybrids from one variable parent, [22];
—graft hybrid produced by inoculation in the vine, [11];
—effect produced by grafts on the stock, [11], [23];
—tendency of hybrid plants to produce double flowers, [18];
—production of perfect fruit by sterile hybrids, [18];
—sexual elective affinity, [19];
—self-impotence in Lobelia, Verbascum, Lilium, and Passiflora, [17] (2);
—on the action of pollen, [16];
—fertilisation of Malva, [11], [27];
—prepotency of pollen, [19];
—prepotency of transmission in species of Nicotiana, [14];
—bud-variation in Pelargonium zonale, [11];
—in Œnothera biennis, [11];
—in Achillæa millefolium, [11];
—effect of manure on the fertility of plants, [18];
—on contabescence, [18];
—inheritance of plasticity, [21];
—villosity of plants, [23].
GASPARINI, a genus of pumpkins, founded on stigmatic characters, [10].
GAUDICHAUD, bud-variation in the pear, [11];
—apple-tree with two kinds of fruit on branch, [11].
GAY, on Fragaria grandiflora, [10];
—on Viola lutea and tricolor, [10];
—on the nectary of Viola grandiflora, [10].
GAYAL, domestication of the, [3].
GAYOT. See Moll.
GEESE (anseres), general fertility of, in captivity, [18].
GEMMATION and fission, [27].
GEMMULES, or cell-gemmules, [27] (3).
GENERATION, alternate, [27] (3).
GENERATION, sexual, [27].
GENET, fertility of the, in captivity, [18]. GENIUS, inheritance of, [12].
Gentiana amarella, [18].
GEOFFROY SAINT-HILAIRE, production of monstrous chickens, [23];
—“Loi de l’affinite de soi pour soi,” [26];
—compensation of growth, [26].
GEOFFROY SAINT-HILAIRE, ISID., origin of the dog, [1];
—barking of a jackal, [1];
—period of gestation and odour of the jackal, [1];
—anomalies in the teeth of dogs, [1];
—variations in the proportions of dogs, [1];
—webbed feet of Newfoundland dogs, [1];
—crossing of domestic and wild cats, [1];
—domestication of the arni, [3];
—supposed introduction of cattle into Europe from the East, [3];
—absence of interdigital pits in sheep, [3];
—origin of the goat, [3];
—feral geese, [6];
—ancient history of the fowl, [7];
—skull of the Polish fowl, [7];
—preference of the Romans for the liver of white geese, [8];
—polydactylism, [12];
—assumption of male characters by female bird, [13];
—transmission and blending of characters in hybrids, [15];
—refusal of animals to breed in captivity, [18];
—on the Guinea-pig, [18];
—silkworms producing white cocoons, [20];
—on the carp, [21];
—on Helix lactea, [23];
—on monstrosities, [22];
—injury to the embryo a cause of monstrosity, [22];
—alteration in the coat of horses in coal-mines, [23];
—length of the intestines in wild and tame animals, [24] (2);
—inheritance of rudimentary limbs in the dog, [24];
—correlation in monstrosities, [25];
—supernumerary digits in man, [25];
—co-existence of anomalies, [25];
—presence of hairs and teeth in ovarian tumours, [27];
—development of teeth on the palate in the horse, [27].
GEOGRAPHICAL differences of faunas, [Introduction].
GEOLOGICAL succession of organisms, [Introduction].
Geranium, [13].
Geranium phæum and pyrenaicum, [22].
Geranium pratense, [11].
GERARD, asserted climatal change in Burgundian bees, [8].
GERARDE, on varieties of the hyacinth, [10].
GERSTÄCKER, on hive-bees, [8].
GERVAIS, Prof., origin of the dog, [1];
—resemblance of dogs and jackals, [1];
—taming of the jackal, [1];
—number of teeth in dogs, [1];
—breeds of dogs, [1];
—on tertiary horses, [2];
—Biblical notices of horses, [2];
—species of Ovis, [3];
—wild and domestic rabbits, [4];
—rabbits from Mount Sinai and Algeria, [4];
—earless rabbits, [4];
—batrachia with doubled limbs, [27].
GESTATION, period of, in the dog, wolf, etc., [1];
—in the pig, [3] (2);
—in cattle, [3], [25];
—in sheep, [3].
GESTURES, inheritance of peculiarities in, [12].
“GHOONDOOKS” a sub-breed of fowls, [7].
GHOR-KHUR, [13].
GILES, Mr., effect of cross-breeding in the pig, [11].
GIRAFFE, co-ordination of structure of, [20].
GIRARD, period of appearance of permanent teeth in dogs, [1].
GIRAUD-TEULON, cause of short sight, [12].
GIROU DE BUZAREINGUES, inheritance in the horse, [12];
—reversion by age in cattle, [13];
—prepotency of transmission of character in sheep and cattle, [14];
—on crossing gourds, [16].
GISBURNE, wild cattle at, [3].
Gladiolus, [10];
—self-impotence of hybrids of, [17].
Gladiolus colvillii, bud-variation in, [11].
GLANDS, compensatory development of, [24].
GLASTONBURY thorn, [10].
GLENNY, Mr., on the Cineraria, [20].
GLOEDE, F., on strawberries, [10].
GLOGER, on the wings of ducks, [24].
“GLOUGLOU” (pigeon), [5].
Gloxiniæ, peloric, [10], [18].
GMELIN, on red cats, at Tobolsk, [1].
GOAT, [3] (2);
—polydactylism in the, [12];
—sexual differences in horns of, [14];
—valued by South Africans, [20];
—Thibet, [23];
—amount of milk and development of udders in the, [24];
—hornless, rudimentary bony cores in, [24];
—Angora, [25].
GODINE, on prepotency of transmission., [14]
GODRON, odour of the hairless Turkish dog, [1];
—differences in the skull of dogs, [1];
—increase of breeds of horses, [2];
—crossing of domestic and wild swine, [3];
—on goats, [3] (2);
—colour of the skin in fowls, [7];
—bees of north and south of France, [8];
—introduction of the silkworm into Europe, [8];
—variability in the silkworm, [8];
—supposed species of wheat, [9] (2);
—on Ægilops triticoides,, [9];
—variable presence of barbs in grasses, [9];
—colours of the seeds of maize, [9];
—unity of character in cabbages, [9];
—correlation of colour and odour, [9];
—effect of heat and moisture on the cabbage, [9];
—on the cultivated species of Brassica, [9];
—on the Rouncival and sugar peas, [9];
—variation in the numbers of peas in the same pod, [9];
—wild vines in Spain, [10];
—on raising peaches from seed, [10];
—supposed specific distinctness of peach and nectarine, [10];
—nectarine producing peaches, [10];
—on the flower of Corydalis, [26];
—origin and variations of the plum, [10];
—origin of the cherry, [10];
—reversion of single-leaved strawberries, [10];
—five-leaved variety of Fragaria collina, [10];
—supposed immutability of specific characters, [10] (2);
—varieties of Robinia, [10];
—permanency of the simple-leaved ash, [10];
—non-inheritance of certain mutilations, [12];
—wild turnips, carrots, and celery, [13];
—peloria, [13];
—prepotency of a goat-like ram, [14];
—benefit of change of soil to plants, [18];
—fertility of peloric flowers of Corydalis solida, [18];
—seeding of ordinarily seedless fruit, [18];
—sexual sterility of plants propagated by buds, etc., [18];
—increase of sugar in beet-root, [20];
—effects of selection in enlarging particular parts of plants, [20];
—growth of the cabbage in the tropics, [23];
—rejection of bitter almonds by mice, [21];
—influence of marshy pasture on the fleece of sheep, [23];
—on the ears of ancient Egyptian pigs, [24];
—primitive distinctness of species, [28];
—solid-hoofed swine, [28].
GOETHE, on compensation of growth, [26].
GOLD-FISH, [8] (2), [21].
GOMARA, on South American cats, [1].
GONGORA, number of seeds in the, [27].
GOODMAN, three-toed cows, [12].
GOOSE, ancient domestication of, [8];
—sacred to Juno in Rome, [8];
—inflexibility of organisation of, [8];
—skull perforated in tufted, [8];
—characters of breeds and sub-breeds of, [8] (2);
—variety of, from Sebastopol, [8], [27];
—feral, in La Plata, [6];
—Egyptian, hybrid of, with penguin duck, [14];
—spontaneous segregation of varieties of, [16];
—fertility of, increased by domestication, [16];
—decreased fertility of, in Bogota, [18];
—sterility of, in the Philippine Islands, [18];
—selection of, [20];
—white, preference of the Romans for the liver of, [20];
—persistency of character in, [22];
—Egyptian, change in breeding season of, [24].
GOOSEBERRY, [10];
—bud-variation in the, [11];
—Whitesmith’s, [21].
GÖPPERT, on monstrous poppies, [18].
GOSSE, P. H., feral dogs in Jamaica, [1];
—feral pigs of Jamaica, [3];
—feral rabbits of Jamaica, [4];
—on Columba leucocephala, [6];
—feral Guinea fowl in Jamaica, [6];
—reproduction of individual peculiarities by gemmation in a coral, [11];
—frequency of striped legs in mules, [13].
GOULD, Dr., on hereditary hæmorrhage, [12].
GOULD, JOHN, origin of the turkey, [8].
Goura coronata and Victoriæ, hybrids of, [6], [18].
GOURDS, [10];
—crossing of varieties of, [16];
—ancient Peruvian variety of, [28].
GOUT, inheritance of, [12];
—period of appearance of, [14].
GRABA, on the pigeon of the Faroe Islands, [6].
GRAFTING, [18];
—effects of, [22] (2);
—upon the stock, [11];
—upon the variability of trees, [22];
—changes analogous to bud-variation produced by, [11] (2).
GRAFT-HYBRIDS, [11] (2), [27].
GRAPES, bud-variation in, [11];
—cross of white and purple, [11];
—green, liable to disease, [25];
—effect of foreign pollen on, [11].
GRASSES, seeds of, used as food by savages, [9].
GRAY, ASA, superior wild varieties of fruit-trees, [9];
—cultivated native plants of North America, [9], [10];
—non-variation of weeds, [9];
—supposed spontaneous crossing of Cucurbitaceæ, [11];
—pre-ordination of variation, [11];
—progeny of husked form of maize, [9];
—wild intermediate forms of strawberries, [10].
GRAY, G. R., on Columba gymnocyclus,, [6].
GRAY, J. E., on Sus pliciceps, [3];
—on a variety of the gold-fish, [8];
—hybrids of the ass and zebra, [13] (2);
—on the breeding of animals at Knowsley, [18];
—on the breeding of birds in captivity, [18].
GREENE, J. REAY, on the development of the echinodermata, [27].
GREENHOW, Mr., on a Canadian web-footed dog, [1].
GREENING, Mr., experiments on Abraxas grossulariata, [23].
GREGSON, Mr., experiments on Abraxas grossulariata, [23].
GREY, Sir GEORGE, preservation of seed-bearing plants by the Australian savages, [9];
—detestation of incest by Australian savages, [17].
GREYHOUNDS, sculptured on Egyptian monuments, and in the Villa of Antoninus, [1];
—modern breed of, [1];
—crossed with the bulldog, by Lord Orford, [3];
—close interbreeding of, [17];
—co-ordination of structure of, due to selection, [20] (2);
—Italian, [21].
GREYNESS, inherited at corresponding periods of life, [14].
GRIEVE, Mr., on early-flowering dahlias, [10].
GRIGOR, Mr., acclimatisation of the Scotch fir, [24].
GRÖNLAND, hybrids of Ægilops and wheat, [16].
GROOM-NAPIER, C. O., on the webbed feet of the otter-hound, [1].
GROS, on Pangenesis, [27].
“GROSSES-GORGES” (pigeons), [5].
GROUND-TUMBLER, Indian, [5].
GROUSE, fertility of, in captivity, [18].
Grus montigresia, cinerea, and antigone, [18].
GUANACOS, selection of, [20].
GUANS, general fertility of, in captivity, [18].
GUELDER-ROSE, [19].
GUELDERLAND fowls, [6].
GUIANA, selection of dogs by the Indians of, [20].
GUINEA fowl, [8];
—feral, in Ascension and Jamaica, [6], [13];
—indifference of, to change of climate, [18].
GUINEA pig, [12], [18].
GÜLDENSTADT, on the jackal, [1].
GULL, herring, breeding in confinement, [18].
GULLS, general sterility of, in captivity, [18].
Gulo, sterility of, in captivity, [18].
GÜNTHER, A., on tufted ducks and geese, [7];
—on the regeneration of lost parts in batrachia, [27].
GURNEY, Mr., owls breeding in captivity, [18];
—appearance of “black-shouldered” among ordinary peacocks, [8].
HABIT, influence of, in acclimatisation, [24].
HÄCKEL, on fissiparous reproduction, [27];
—on cells, [27];
—on the double reproduction of medusæ, [27];
—on inheritance, [27].
HACKLES, peculiarities of, in fowls, [7].
HAIR, on the face, inheritance of, in man, [12];
—peculiar lock of, inherited, [12];
—growth of, under stimulation of skin, [25];
—homologous variation of, [25];
—development of, in the brain, [27].
HAIR and teeth, correlation of, [25].
HAIRY family, corresponding period of inheritance in, [14].
HALF-CASTES, character of, [13].
HALF-LOP rabbits, figured and described, [4], (2);
—skull of, [4].
Haliætus leucocephalus, copulating in captivity, [18].
HALLAM, Col., on a two-legged race of pigs, [12].
HALLET, Major, selection in cereals, [5];
—on pedigree wheat, [9].
HAMBURGH fowl, [7] (2);
—figured, [7].
HAMILTON, wild cattle of, [3].
HAMILTON, Dr., on the assumption of male plumage by the hen pheasant, [13].
HAMILTON, F. BUCHANAN, on the shaddock, [10];
—varieties of Indian cultivated plants, [22].
HANCOCK, Mr., sterility of tamed birds, [18] (2).
HANDWRITING, inheritance of peculiarities in, [12].
HANMER, Sir J., on selection of flower-seeds, [20].
HANSELL, Mr., inheritance of dark yolks in duck’s eggs, [8].
HARCOURT, E. V., on the Arab boar-hound, [1];
—aversion of the Arabs to dun-coloured horses, [2].
HARDY, Mr., effect of excess of nourishment on plants, [22].
HARE, hybrids of, with rabbit, [4];
—sterility of the, in confinement, [18];
—preference of, for particular plants, [21].
HARE-LIP, inheritance of, [12].
HARLAN, Dr., on hereditary diseases, [12].
HARTMAN, on the wild ass, [2].
HARVEY, Mr., monstrous red and white African bull, [3].
HARVEY, Prof., singular form of Begonia frigida, [10];
—effects of cross-breeding on the female, [11];
—monstrous saxifrage, [18].
HASORA wheat, [9].
HAUTBOIS strawberry, [10].
HAWKER, Col., on call or decoy ducks, [8].
HAWTHORN, varieties of, [10] (2);
—pyramidal, [10];
—pendulous hybridised, [12];
—changes of, by age, [10], [11];
—bud-variation in the, [11];
—flower buds of, attacked by bullfinches, [21].
HAYES, Dr., character of Esquimaux dogs, [1].
HAYWOOD, W., on the feral rabbits of Porto Santo, [4].
HAZEL, purple-leaved, [10], [11], [25].
HEAD of wild boar and Yorkshire pig, figured, [3].
HEAD and limbs, correlated variability of, [25].
HEADACHE, inheritance of, [14].
HEARTSEASE, [10];
—change produced in the, by transplantation, [11];
—reversion in, [13] (2);
—effects of selection on, [20];
—scorching of, [21];
—effects of seasonal conditions on the, [23];
—annual varieties of the, [24].
HEAT, effect of, upon the fleece of sheep, [3].
HEBER, Bishop, on the breeding of the rhinoceros in captivity, [18].
HEBRIDES, cattle of the, [3];
—pigeons of the, [6].
HEER, O., on the plants of the Swiss lake-dwellings, [9];
—on the cereals, [9];
—on the peas, [9];
—on the vine growing in Italy in the Bronze age, [10].
HEIMANN, potato-grafting, [11].
Helix lactea, [23].
Hemerocallis fulva and flava, interchanging by bud-variation, [11].
HEMLOCK, yields no conicine in Scotland, [23].
HEMP, differences of, in various parts of India, [18];
—climatal difference in products of, [23].
HEMPSEED, effect of, upon the colour of birds, [23].
HERMAPHRODITE flowers, occurrence of, in maize, [9].
HEN, assumption of male characters by the, [13] (2);
—development of spurs in the, [24].
“HENNIES,” or hen-like male fowls, [7].
HENRY, T. A., a variety of the ash produced by grafting, [11];
—crossing of species of Rhododendron and Arabis, [11].
HENSLOW, Prof., individual variation in wheat, [9];
—bud-variation in the Austrian bramble rose, [11];
—partial reproduction of the weeping ash by seed, [12].
HEPATICA, changed by transplantation, [11].
HERBERT, Dr., variations of Viola grandiflora, [10];
—bud-variation in camellias, [11];
—seedlings from reverted Cytisus adami,, [11];
—crosses of Swedish and other turnips, [15];
—on hollyhocks, [20];
—breeding of hybrids, [17];
—self-impotence in hybrid hippeastrums, [17] (2);
—hybrid Gladiolus, [17];
—on Zephyranthes candida, [18];
—fertility of the crocus, [18];
—on contabescence, [18];
—hybrid Rhododendron, [22].
HERCULANEUM, figure of a pig found in, [3].
HERON, Sir R., appearance of “black-shouldered” among ordinary peacocks, [8] (2);
—non-inheritance of monstrous characters by gold-fish, [8];
—crossing of white and coloured Angora rabbits, [15];
—crosses of solid-hoofed pigs, [15].
Herpestes fasciatus and griseus, [18].
HEUSINGER, on the sheep of the Tarentino, [21];
—on correlated constitutional peculiarities, [25].
HEWITT, Mr., reversion in bantam cocks, [7];
—degeneration of silk fowls, [7];
—partial sterility of hen-like male fowls, [7];
—production of tailed chickens by rumpless fowls, [7];
—on taming and rearing wild ducks, [8], [21], [22];
—conditions of inheritance in laced Sebright bantams, [12];
—reversion in rumpless fowls, [13];
—reversion in fowls by age, [13];
—hybrids of pheasant and fowl, [13], [14];
—assumption of male characters by female pheasants, [13];
—development of latent characters in a barren bantam hen, [13];
—mongrels from the silk fowl, [14];
—effects of close interbreeding on fowls, [17] (2);
—on feather-legged bantams, [25].
HIBBERT, Mr., on the pigs of the Shetland Islands, [3].
HIBISCUS, See Paritium.
HIGHLAND cattle, descended from Bos longifrons, [3].
HILDEBRAND, Dr., on graft-hybrids with the potato, [11];
—on the influence of pollen on the mother-plant, [11];
—on the fertilisation of Orchideæ, [11] (2);
—occasional necessary crossing of plants, [15];
—on seeds not fitted for distribution, [9];
—potato-grafting, [11];
—crossing of varieties, [16];
—on Primula sinensis and Oxalis rosea, [17];
—on Corydalis cava, [17] (2).
HILL, R., on the Alco, [1];
—feral rabbits in Jamaica, [4];
—feral peacocks in Jamaica, [6];
—variation of the Guinea fowl in Jamaica, [8];
—sterility of tamed birds in Jamaica, [18] (2).
HIMALAYA, range of gallinaceous birds in the, [7].
HIMALAYAN rabbit, [4] (2);
—skull of, [4].
HIMALAYAN sheep, [3].
HINDMARSH, Mr., on Chillingham cattle, [3].
“HINKEL-TAUBE,” [5] (2).
HINNY and mule, difference of, [14].
Hipparion, anomalous resemblance to, in horses, [2].
Hippeastrum, hybrids of, [17] (2).
HIVE-BEES, ancient domestication of, [8];
—breeds of, [8];
—smaller when produced in old combs, [8];
—variability in, [8];
—crossing of Ligurian and common, [8].
HOBBS, FISHER, on interbreeding pigs, [17].
“HOCKER-TAUBE,” [5].
HODGKIN, Dr., on the attraction of foxes by a female Dingo, [1];
—origin of the Newfoundland dog, [1];
—transmission of a peculiar lock of hair, [12].
HODGSON, Mr., domestication of Canis primævus, [1];
—development of a fifth digit in Thibet mastiffs, [1];
—number of ribs in humped cattle, [3];
—on the sheep of the Himalaya, [3];
—presence of four mammæ in sheep, [3];
—arched nose in sheep, [3];
—measurements of the intestines of goats, [3];
—presence of interdigital pits in goats, [3];
—disuse a cause of drooping ears, [24].
HOFACKER, persistency of colour in horses, [2], [12];
—production of dun horses from parents of different colours, [2];
—inheritance of peculiarities in handwriting, [12];
—heredity in a one horned stag, [12];
—on consanguineous marriages, [17].
HOFFMAN, Prof., on Raphanus, [9].
HOG, Red River, [18].
HOGG, Mr., retardation of breeding in cows by hard living, [16].
HOLLAND, Sir H., necessity of inheritance, [12];
—on hereditary diseases, [12];
—hereditary peculiarity in the eyelid, [12];
—morbid uniformity in the same family, [12];
—transmission of hydrocele through the female, [13];
—inheritance of habits and tricks, [27].
HOLLY, varieties of the, [10] (2);
—bud-reversion in, [11];
—yellow-berried, [12], [21].
HOLLYHOCK, bud-variation in, [11];
—non-crossing of double varieties of, [16];
—tender variety of the, [24].
HOMER, notice of geese, [8];
—breeding of the horses of Æneas, [20].
HOMOLOGOUS parts, correlated variability of, [25], [26] (2);
—fusion of, [26];
—affinity of, [26] (2).
HOOFS, correlated with hair in variation, [25].
HOOK-BILLED duck, skull figured, [8].
HOOKER, Dr. J. D., forked shoulder-stripe in Syrian asses, [2];
—voice of the cock in Sikkim, [7];
—use of Arum-roots as food, [9];
—native useful plants of Australia, [9];
—wild walnut of the Himalayas, [10];
—variety of the plane-tree, [10];
—production of Thuja orientalis from seeds of T. pendula, [10];
—singular form of Begonia frigida, [10];
—reversion in plants run wild, [13];
—on the sugar-cane, [18];
—on Arctic plants, [22];
—on the oak grown at the Cape of Good Hope, [23];
—on Rhododendron ciliatum, [23];
—stock and mignonette perennial in Tasmania, [24].
HOPKIRK, Mr., bud-variation in the rose, [11];
—in Mirabilis jalapa, [11];
—in Convolvulus tricolor, [11].
HORNBEAM, heterophyllous, [10].
HORNED fowl, [7];
—skull figured, [7].
HORNLESS cattle in Paraguay, [3].
HORNS of sheep, [3];
—correlation of, with fleece in sheep, [25];
—correlation of, with the skull, [25];
—rudimentary in young polled cattle, [24];
—of goats, [3].
HORSES, in Swiss lake-dwellings, [2];
—different breeds of, in Malay Archipelago, [2];
—anomalies in osteology and dentition of, [2];
—mutual fertility of different breeds, [2];
—feral, [2];
—habit of scraping away snow, [2];
—mode of production of breeds of, [2];
—inheritance and diversity of colour in, [2];
—dark stripes in, [2];
—dun-coloured, origin of, [2];
—colours of feral, [3] (2);
—effect of fecundation by a quagga on the subsequent progeny of, [11];
—inheritance of peculiarities in, [12] (2);
—polydactylism in, [12];
—inheritance of colour in, [12];
—inheritance of exostoses in legs of, [12];
—reversion in, [13] (2);
—hybrids of, with ass and zebra, [13];
—prepotency of transmission in the sexes of, [14];
—segregation of, in Paraguay, [16];
—wild species of, breeding in captivity, [18];
—curly, in Paraguay, [20], [25];
—selection of, for trifling characters, [20];
—unconscious selection of, [20] (2);
—natural selection in Circassia, [21];
—alteration of coat of, in coal-mines, [23];
—degeneration of, in the Falkland Islands, [23];
—diseases of, caused by shoeing, [24];
—feeding on meat, [24];
—white and white-spotted, poisoned by mildewed vetches, [25];
—analogous variations in the colour of, [26];
—teeth developed on palate of, [27];
—of Bronze period in Denmark, [28].
HORSE-CHESTNUT, early, at the Tuileries, [10];
—tendency to doubleness in, [18].
HORSE-RADISH, general sterility of the, [18].
“HOUDAN,” a French sub-breed of fowls, [7].
HOWARD, C., on an Egyptian monument, [1];
—on crossing sheep, [3] (2).
HUC, on the Emperor Khang-hi, [20];
—Chinese varieties of the bamboo, [22].
HUMBOLDT, A., character of the Zambos, [13];
—parrot speaking in the language of an extinct tribe, [18];
—on Pulex penetrans, [23].
HUMIDITY, injurious effect of, upon horses, [2].
HUMPHREYS, Col., on Ancon sheep, [3].
HUNGARIAN cattle, [3].
HUNTER, JOHN, period of gestation in the dog, [1];
—on secondary sexual characters, [3];
—fertile crossing of Anser ferus and the domestic goose, [8];
—inheritance of peculiarities in gestures, voice, etc., [12];
—assumption of male characters by the human female, [13];
—period of appearance of hereditary diseases, [14];
—graft of the spur of a cock upon its comb, [24];
—on the stomach of Larus tridentatus, [24].
HUNTER, W., evidence against the influence of imagination upon the offspring, [22].
HUTH, Mr., close interbreeding of rabbits, [17];
—consanguineous marriages, [17].
HUTTON, Capt., on the variability of the silk-moth, [8];
—on the number of species of silkworms, [8];
—markings of silkworms, [8];
—domestication of the rock-pigeon in India, [6];
—domestication and crossing of Gallus bankiva, [7];
—reversion in goats from a cross, [13].
HUTCHINSON, Col., liability of dogs to distemper, [1].
HUXLEY, Prof., on the transmission of polydactylism, [12];
—on unconscious selection, [20];
—on correlation in the mollusca, [25];
—on gemmation and fission, [27];
—development of star-fishes, [27].
HYACINTHS, [10];
—bud-variation in, [11];
—graft-hybrid by union of half bulbs of, [11];
—white, reproduced by seed, [12];
—red, [21];
—varieties of, recognisable by the bulb, [22].
HYACINTH, feather, [19], [24].
Hyacinthus orientalis, [10].
Hybiscus syriacus, [23].
HYBRIDS, of hare and rabbit, [6];
—of various species of Gallus, [7];
—of almond, peach, and nectarine, [10];
—naturally produced, of species of Cytisus, [11];
—from twin-seed of Fuchsia coccinea and fulgens, [11];
—reversion of, [11] (2), [13] (2);
—from mare, ass, and zebra, [13];
—of tame animals, wildness of, [13] (2);
—female instincts of sterile male, [13];
—transmission and blending of characters in, [15];
—breed better with parent species than with each other, [17];
—self-impotence in, [17];
—readily produced in captivity, [18].
HYBRIDISATION, singular effects of, in oranges, [10];
—of cherries, [10];
—difficulty of, in Cucurbitæ, [10];
—of roses, [10].
HYBRIDISM, [19];
—the cause of a tendency to double flowers, [18];
—in relation to Pangenesis, [27].
HYBRIDITY in cats, [1] (2);
—supposed, of peach and nectarine, [10].
Hydra, [11], [24], [27].
HYDRANGEA, colour of flowers of, influenced by alum, [23].
HYDROCELE, [13].
HYDROCEPHALUS, [24].
Hypericum calycinum, [18].
Hypericum crispum, [21], [25].
HYPERMETAMORPHOSIS, [27].
HYPERMETROPIA, hereditary, [12].
ICHTHYOPTERYGIA, number of digits in the, [13].
Ilex aquifolium, [12].
IMAGINATION, supposed effect of, on offspring, [22].
Imatophyllum miniatum, bud-variation in, [11].
INCEST, abhorred by savages, [17].
INCUBATION, by crossed fowls of non-sitting varieties, [13].
INDIA, striped horses of, [2];
—pigs of, [3] (2);
—breeding of rabbits in, [4];
—cultivation of pigeons in, [6].
INDIVIDUAL variability in pigeons, [5].
INGLEDEW, Mr., cultivation of European vegetables in India, [18].
“INDISCHE Taube,” [5].
INHERITANCE, [12], [27], (2);
—doubts entertained of, by some writers, [12];
—importance of, to breeders, [11], [12];
—evidence of, derived from statistics of chances, [12];
—of peculiarities in man, [12], (2);
—of disease, [12] (3);
—of peculiarities in the eye, [12];
—of deviations from symmetry, [12];
—of polydactylism, [12];
—capriciousness of, [12];
—of mutilations, [12];
—of congenital monstrosities, [12];
—causes of absence of, [12];
—by reversion or atavism, [13];
—its connection with fixedness of character, [14];
—affected by prepotency of transmission of character, [14];
—limited by sex, [14];
—at corresponding periods of life, [14];
—summary of the subject of, [14];
—laws of, the same in seminal and bud varieties, [11];
—of characters in the horse, [2];
—in cattle, [3];
—in rabbits, [4];
—in the peach, [10];
—in the nectarine, [10];
—in plums, [10];
—in apples, [10];
—in pears, [10];
—in the pansy, [10];
—of primary characters of Columba livia in crossed pigeons, [5];
—of peculiarities of plumage in pigeons, [5];
—of peculiarities of foliage in trees, [10];
—effects of, in varieties of the cabbage, [9].
INSANITY, inheritance of, [12], [14].
INSECTS, regeneration of lost parts in, [10], [24];
—agency of, in fecundation of larkspurs, [12];
—effect of changed conditions upon, [18];
—sterile neuter, [19];
—monstrosities in, [22], [27].
INSTINCTS, defective, of silkworms, [8].
INTERBREEDING, close, ill effects of, [17], [19].
INTERCROSSING, of species, as a cause of variation, [6];
—natural, of plants, [10];
—of species of Canidæ and breeds of dogs, [1];
—of domestic and wild cats, [1] (2);
—of breeds of pigs, [3] (2);
—of cattle, [3];
—of varieties of cabbage, [9];
—of peas, [9] (3);
—of varieties of orange, [10];
—of species of strawberries, [10] (2);
—of Cucurbitæ, [10] (2);
—of flowering plants, [10];
—of pansies, [10].
INTERDIGITAL pits, in goats, [3].
INTERMARRIAGES, close, [17] (2).
INTESTINES, elongation of, in pigs, [3];
—relative measurement of parts of, in goats, [3];
—effects of changed diet on, [24].
Ipomœa purpurea, [17].
IRELAND, remains of Bos frontosus and longifrons found in, [3].
IRIS, hereditary absence of the, [12];
—hereditary peculiarities of colour of the, [12];
—variation of, [11].
Iris xiphium, [11].
IRISH, ancient, selection practised by the, [20].
IRON period, in Europe, dog of, [1].
ISLANDS, oceanic, scarcity of useful plants on, [9].
ISLAY, pigeons of, [6].
ISOLATION, effect of, in favour of selection, [21] (2).
ITALY, vine-growing in, during the Bronze period, [10].
IVY, sterility of, in the north of Europe, [18].
JACK, Mr., effect of foreign pollen on grapes, [11].
JACKAL, [1] (3);
—hybrids of, with the dog, [1];
—prepotency of, over the dog, [1].
JACKSON, Mr., white-footed cats, [25].
JACOBIN pigeon, [5], [6].
JACQUEMET-BONNEFORT, on the mulberry, [10].
JAEGER, Prof., on reversion in pigs, from a cross, [13];
—white pigeons killed by hawks, [21].
JAGUAR, with crooked legs, [1].
JAMAICA, feral dogs of, [1];
—feral pigs of, [3];
—feral rabbits of, [4].
JAMESON, Mr., on hybrid potatoes, [11].
JAPAN, horses of, [2].
JAPANESE pig (figured), [3].
JARDINE, Sir W., crossing of domestic and wild cats, [1].
JARVES, J., silkworm in the Sandwich Islands, [8].
JAVA, fantail pigeon in, [5].
JAVANESE ponies, [2] (2).
JEITTELES, history of the dog, [1];
—history of the fowl, [7];
—Hungarian sheep-dogs, [1];
—crossing of domestic and wild cats, [1].
JEMMY BUTTON, [9].
JENYNS, L., whiteness of ganders, [8];
—sunfish-like variety of the goldfish, [8].
JERDON, J. C., number of eggs laid by the pea-hen, [20];
—origin of domestic fowl, [7].
JERSEY, arborescent cabbages of, [9].
JESSAMINE, [11].
JESSE, G. R., on the bulldog, [1].
JOHN, King, importation of stallions from Flanders by, [20].
JOHNSON, D., occurrence of stripes on young wild pigs in India, [3].
JORDAN, A., on Vibert’s experiments on the vine, [10];
—origin of varieties of the apple, [10];
—varieties of pears found wild in woods, [22].
JOURDAN, parthenogenesis in the silk-moth, [27].
JUAN DE NOVA, wild dogs on, [1].
JUAN FERNANDEZ, dumb dogs on, [1].
Juglans regia, [10].
JUKES, Prof., origin of the Newfoundland dog, [1].
JULIEN, Stanislas, early domestication of pigs in China, [3];
—antiquity of the domestication of the silkworm in China, [8].
JUMPERS, a breed of fowls, [7].
JUNIPER, variations of the, [10] (2).
Juniperus suecica, [10].
Jussiæa grandiflora, [18].
JUSSIEU, A. de, structure of the pappus in Carthamus, [24].
KAIL, Scotch, reversion in, [13].
KALES, [9].
“KALI-PAR” pigeon, [5].
KALM, P., on maize, [9], [24];
—introduction of wheat into Canada, [9];
—sterility of trees growing in marshes and dense woods, [18].
“KALMI LOTAN” tumbler pigeon, [5].
KANE, Dr., on Esquimaux dogs, [1].
KARAKOOL sheep, [3].
KARKEEK, on inheritance in the horse, [12].
“KARMELITEN Taube,” [5].
KARSTEN on Pulex penetrans, [23].
KATTYWAR horses, [2].
KEELEY, R., pelorism in Galeobdolon luteum, [13].
KERNER, on the culture of Alpine plants, [18];
—definite action of conditions, [23].
KESTREL, breeding in captivity, [18].
“KHANDÉSI,” [5].
KHANG-HI, selection of a variety of rice by, [20].
KIANG, [13].
KIDD, on the canary-bird, [8], [14].
KIDNEY bean, [10];
—varieties of, [22], [23].
KIDNEYS, compensatory development of the, [24];
—shape of, in birds influenced by the form of the pelvis, [26].
KING, Col., domestication of rock doves from the Orkneys, [6] (2).
KING, Dr., on Paritium, [11].
KING, P. P., on the dingo, [1] (2).
KIRBY and Spence, on the growth of galls, [23].
KIRGHISIAN sheep, [3].
KITE, breeding in captivity, [18].
KLEINE, variability of bees, [8].
KNIGHT, ANDREW, on crossing horses of different breeds, [2];
—crossing varieties of peas, [9], [17];
—persistency of varieties of peas, [9];
—origin of the peach, [10];
—hybridisation of the morello by the Elton cherry, [10];
—on seedling cherries, [10];
—variety of the apple not attacked by coccus, [10];
—intercrossing of strawberries, [10] (2);
—broad variety of the cock’s-comb, [10];
—bud variation in the cherry and plum, [11];
—crossing of white and purple grapes, [11];
—experiments in crossing apples, [11], [17];
—hereditary disease in plants, [12];
—on interbreeding, [17];
—crossed varieties of wheat, [17];
—necessity of intercrossing in plants, [19];
—on variation, [22] (2);
—effects of grafting, [11], [23];
—bud-variation in a plum, [23];
—correlated variation of head and limbs, [8].
KNOX, Mr., breeding of the eagle owl in captivity, [18].
KOCH, degeneracy in the turnip, [9].
KOHLRABI, [9].
KÖLREUTER, reversion in hybrids, [11], [13];
—acquired sterility of crossed varieties of plants, [10], [16];
—absorption of Mirabilis vulgaris by M. longiflora, [15];
—crosses of species of Verbascum, [15], [16];
—on the hollyhock, [16];
—crossing varieties of tobacco, [16];
—benefits of crossing plants, [17] (2), [19] (2);
—sell-impotence in Verbascum, [17] (2);
—effects of conditions of growth upon fertility in Mirabilis, [18];
—great development of tubers in hybrid plants, [18];
—inheritance of plasticity, [21];
—variability of hybrids of Mirabilis, [22];
—repeated crossing a cause of variation, [22];
—number of pollen-grains necessary for fertilisation, [27].
“KRAUSESCHWEIN,” [3].
KROHN, on the double reproduction of Medusæ, [27].
“KROPF-TAUBEN,” [5].
LABAT, on the tusks of feral boars in the West Indies, [5];
—on French wheat grown in the West Indies, [24];
—on the culture of the vine in the West Indies, [24].
LABURNUM, Adam’s, see Cytisus adami,;
—oak-leaved, reversion of, [11];
—pelorism in the, [26];
—Waterer’s, [11].
LACHMANN, on gemmation and fission, [27].
Lachnanthes tinctoria, [21], [25].
LACTATION, imperfect, hereditary, [12];
—deficient, of wild animals in captivity, [18].
LADRONE Islands, cattle of, [3].
LA GASCA, Prof., individual variation in wheat, [9].
LAING, Mr., resemblance of Norwegian and Devonshire cattle, [3].
LAKE-DWELLINGS, sheep of, [3];
—cattle of, [3];
—absence of the fowl in, [7];
—cultivated plants of, [9], [28] (2);
—cereals of, [9];
—peas found in, [9];
—beans found in, [9].
LAMARE-PIQUOT, observations on half-bred North American wolves, [1].
LAMBERT, A. B., on Thuja pendula or filiformis, [10].
LAMBERT family, [12], [14].
LAMBERTYE, on strawberries, [10] (2);
—five-leaved variety of Fragaria collina, [10].
LANDT, L., on sheep in the Faroe Islands, [16].
LANKESTER, RAY, on longevity, [27].
LA PLATA, wild dogs of, [1];
—feral cat from, [1].
LARCH, [24].
LARKSPURS, insect agency necessary for the full fecundation of, [12].
Larus argentatus, [18], [24].
Larus tridactylus, [24].
LASTERYE, merino sheep in different countries, [3].
LATENT characters, [13].
LATHAM, on the fowl not breeding in the extreme north, [18].
Lathyrus, [13].
Lathyrus aphaca, [26].
Lathyrus odoratus, [11] (2), [15] (2), [24].
LA TOUCHE, J. D., on a Canadian apple with dimidiate fruit, [11] (2).
“LATZ-TAUBE,” [5].
LAUGHER pigeon, [5], [6].
Laurus sassafras, [23].
LAWRENCE, J., production of a new breed of foxhounds, [1];
—occurrence of canines in mares, [2];
—on three-parts-bred horses, [2];
—on inheritance in the horse, [12] (2).
LAWSON, Mr., varieties of the potato, [9].
LAXTON, Mr., bud-variation in the gooseberry, [11];
—crossing of varieties of the pea, [11] (2);
—weakness of transmission in peas, [14];
—double-flowered peas, [18].
LAYARD, E. L., resemblance of a Caffre dog to the Esquimaux breed, [1], [23];
—crossing of the domestic cat with Felis caffra, [1];
—feral pigeons in Ascension, [6];
—domestic pigeons of Ceylon, [6];
—on Gallus stanleyi, [7];
—on black-skinned Ceylonese fowls, [7].
LE COMPTE family, blindness inherited in, [14].
LECOQ, bud-variation in Mirabilis jalapa, [11];
—hybrids of Mirabilis, [11], [18], [22];
—crossing in plants, [17];
—fecundation of Passiflora, [17];
—hybrid Gladiolus, [17];
—sterility of Ranunculus ficaria, [18];
—villosity in plants, [23];
—double asters, [24].
LE COUTEUR, J., varieties of wheat, [9];
—acclimatisation of exotic wheat in Europe, [9];
—adaptation of wheat to soil and climate, [9];
—selection of seed-corn, [9];
—evil from inter-breeding, [17];
—on change of soil, [18];
—selection of wheat, [20];
—natural selection in wheat, [21];
—cattle of Jersey, [21].
LEDGER, Mr., on the llama and alpaca, [20].
LEE, Mr., his early culture of the pansy, [10].
Leersia oryzoides, [15].
LEFOUR, period of gestation in cattle, [3].
LEGRAIN, falsified experiments of, [17].
LEGS, of fowls, effects of disuse on, [7];
—characters and variations of, in ducks, [24].
LEGUAT, cattle of the Cape of Good Hope, [3].
LEHMANN, occurrence of wild double-flowered plants near a hot spring, [18].
LEIGHTON, W. A., propagation of a weeping yew by seed, [12].
LEITNER, effects of removal of anthers, [18].
LEMMING, [18].
LEMOINE, variegated Symphytum and Phlox, [11].
LEMON, [10];
—orange fecundated by pollen of the, [11].
LEMURS, hybrid, [4].
LEPORIDES, [18].
LEPSIUS, figures of ancient Egyptian dogs, [1];
—domestication of pigeons in ancient Egypt, [6].
Lepus glacialis, [4].
Lepus magellanicus, [4].
Lepus nigripes, [4].
Lepus tibetanus, [4].
Lepus variabilis, [4].
LEREBOULLET, double monsters of fishes, [26].
LESLIE, on Scotch wild cattle, [3].
LESSONA, on regrowth, [27];
—on Lepus magellanicus, [4].
LETHBRIDGE, previous impregnation, [11].
LEUCKART, on the larva of Cecidomyidæ, [27].
LEWES, G. H., on Pangenesis, [27].
LEWIS, G., cattle of the West Indies, [21].
LHERBETTE and Quatrefages, on the horses of Circassia, [16], [21].
LICHENS, sterility in, [18].
LICHTENSTEIN, resemblance of Bosjesman’s dogs to Canis mesomelas, [1];
—Newfoundland dog at the Cape of Good Hope, [1].
LIEBIG, differences in human blood, according to complexion, [23].
LIEBREICH, occurrence of pigmentary retinitis in deaf-mutes, [25].
LILACS, [18].
LILIACEÆ, contabescence in, [18].
Lilium bulbiferum and davuricum, [11].
Lilium candidum, [17].
LIMBS, regeneration of, [27].
LIMBS and head, correlated variation of, [25].
LIME, effect of, upon shells of the mollusca, [23].
LIME-TREE, changes of, by age, [10], [11].
LIMITATION, sexual, [14].
LIMITATION, supposed, of variation, [28].
Linaria, pelorism in, [13] (2), [14];
—peloric, crossed with the normal form, [14];
—sterility of, [18].
Linaria vulgaris and purpurea, hybrids of, [15].
LINDEMUTH, potato-grafting, [11].
LINDLEY, JOHN, classification of varieties of cabbages, [9];
—origin of the peach, [10];
—influence of soil on peaches and nectarines, [10];
—varieties of the peach and nectarine, [10];
—on the New Town pippin, [10];
—freedom of the Winter Majetin apple from coccus, [10];
—production of monœcious Hautbois strawberries by bud-selection, [10];
—origin of the large tawny nectarine, [11];
—bud-variation in the gooseberry, [11];
—hereditary disease in plants, [12];
—on double flowers, [18];
—seeding of ordinarily seedless fruits, [18];
—sterility of Acorus calamus, [18];
—resistance of individual plants to cold, [24].
LINNÆUS, summer and winter wheat regarded as distinct species by, [9];
—on the single-leaved strawberry, [10];
—sterility of Alpine plants in gardens, [18];
—recognition of individual reindeer by the Laplanders, [22];
—growth of tobacco in Sweden, [24].
LINNET, [18].
Linota cannabina, [18].
Linum, [18].
LION, fertility of, in captivity, [18] (2).
LIPARI, feral rabbits of, [4].
LIVINGSTONE, Dr., striped young pigs on the Zambesi, [3];
—domestic rabbits at Loanda, [4];
—use of grass-seeds as food in Africa, [9];
—planting of fruit-trees by the Batokas, [9];
—character of half-castes, [13];
—taming of animals among the Barotse, [18];
—selection practised in South Africa, [20] (2).
LIVINGSTONE, Mr., disuse a cause of drooping ears, [24].
LIZARDS, reproduction of tail in, [24].
LLAMA, selection of, [20].
LLOYD, Mr., taming of the wolf, [1];
—English dogs in northern Europe, [1];
—fertility of the goose increased by domestication, [8];
—number of eggs laid by the wild goose, [16];
—breeding of the capercailzie in captivity, [18].
LOANDA, domestic rabbits at, [4].
Loasa, hybrid of two species of, [15].
Lobelia, reversion in hybrids of, [11];
—contabescence in, [18].
Lobelia fulgens, cardinalis, and syphilitica, [17].
LOCKHART, Dr., on Chinese pigeons, [6].
LOCUST-TREE, [23].
LOISELEUR-DESLONGCHAMPS, originals of cultivated plants, [9];
—Mongolian varieties of wheat, [9];
—characters of the ear in wheat, [9];
—acclimatisation of exotic wheat in Europe, [9];
—effect of change of climate on wheat, [9];
—on the supposed necessity of the coincident variation of weeds and cultivated plants, [9];
—advantage of change of soil to plants, [18].
Lolium temulentum, variable presence of barbs in, [9].
LONG-TAILED sheep, [3].
LOOCHOO Islands, horses of, [2].
LORD, J. K., on Canis latrans, [1].
“LORI RAJAH,” how produced, [7].
Lorius garrulus, [23].
“LOTAN” tumbler pigeon, [5].
LOUDON, J. W., varieties of the carrot, [9];
—short duration of varieties of peas, [9];
—on the glands of peach-leaves, [10];
—presence of bloom on Russian apples, [10];
—origin of varieties of the apple, [10];
—varieties of the gooseberry, [10];
—on the nut tree, [10];
—varieties of the ash, [10];
—fastigiate juniper (J. suecica), [10];
—on Ilex aquifolium ferox, [10];
—varieties of the Scotch fir, [10] (2);
—varieties of the hawthorn, [10];
—variation in the persistency of leaves on the elm and Turkish oak, [10];
—importance of cultivated varieties, [10];
—varieties of Rosa spinosissima, [10];
—variation of dahlias from the same seed, [10];
—production of Provence roses from seeds of the moss-rose, [11];
—effect of grafting the purple-leaved upon the common hazel, [11];
—intercrossing melons, [17];
—nearly evergreen Cornish variety of the elm, [24].
LOW, on the pigs of the Orkney Islands, [3].
LOW, Prof., pedigrees of greyhounds, [12];
—origin of the dog, [1];
—burrowing instinct of a half-bred dingo, [1];
—inheritance of qualities in horses, [2];
—comparative powers of English racehorses, Arabs, etc., [2];
—British breeds of cattle, [3];
—wild cattle of Chartley, [3];
—effect of abundance of food on the size of cattle, [3];
—effects of climate on the skin of cattle, [3], [25];
—on interbreeding, [17];
—selection in Hereford cattle, [20];
—formation of new breeds, [21];
—on “sheeted” cattle, [26].
LOWE, Mr., on hive bees, [8].
LOWE, Rev. Mr., on the range of Pyrus malus and P. acerba, [10].
LOWNE, Mr., monsters, [26];
—on gemmules, [27].
“LOWTUN” tumbler pigeon, [5].
Loxia pyrrhula, [5].
LUBBOCK, Sir J., developments of the Ephemeridæ, [27].
LUCAS, P., effects of cross-breeding on the female, [11];
—hereditary diseases, [12], [14] (2);
—hereditary affections of the eye, [12] (2);
—inheritance of anomalies in the human eye and in that of the horse, [12];
—inheritance of polydactylism, [12];
—morbid uniformity in the same family, [12];
—inheritance of mutilations, [12];
—persistency of cross-reversion, [13];
—persistency of character in breeds of animals in wild countries, [14];
—prepotency of transmission, [14] (2);
—supposed rules of transmission in crossing animals, [14];
—sexual limitations of transmission of peculiarities, [14] (2);
—absorption of the minority in crossed races, [15];
—crosses without blending of certain characters, [15];
—on interbreeding, [17];
—variability dependent on reproduction, [22];
—period of action of variability, [22];
—inheritance of deafness in cats, [25];
—complexion and constitution, [25].
LUCAZE-DUTHIERS, structure and growth of galls, [23].
LUCAE, Prof., on the masked pig, [3];
—on pigs, [24].
LUIZET, grafting of a peach-almond on a peach, [10].
LUTKE, cats of the Caroline Archipelago, [1].
LUXURIANCE, of vegetative organs, a cause of sterility in plants, [18] (2).
LYONNET, on the scission of Nais, [27].
Lysimachia nummularia, sterility of, [18].
Lythrum, trimorphic species of, [27].
Lythrum salicaria, [19];
—contabescence in, [18].
Lytta vesicatoria, affecting the kidneys, [27].
Macacus, species of, bred in captivity, [18].
MACAULAY, Lord, improvement of the English horse, [20].
M’CLELLAND, Dr., variability of fresh-water fishes in India, [22].
M’COY, Prof., on the dingo, [1].
MACFAYDEN, influence of soil in producing sweet or bitter oranges from the same seed, [10].
MACGILLIVRAY, domestication of the rock-dove, [6];
—feral pigeons in Scotland, [6];
—number of vertebræ in birds, [7];
—on wild geese, [8];
—number of eggs of wild and tame ducks, [16].
MACKENZIE, Sir G., peculiar variety of the potato, [9].
MACKENZIE, P., bud-variation in the currant, [11].
MACKINNON, Mr., horses of the Falkland Islands, [2];
—feral cattle of the Falkland Islands, [3].
MACKNIGHT, C., on interbreeding cattle, [17].
MACNAB, Mr., on seedling weeping birches, [12];
—non-production of the weeping beech by seed, [12].
MADAGASCAR, cats of, [1].
MADDEN, H., on interbreeding cattle, [17].
MADEIRA, rock pigeon of, [6].
Magnolia grandiflora, [24].
MAGNUS, Herr, on potato-grafting, [11];
—on graft-hybrids, [11] (2).
MAIZE, its unity of origin, [9];
—antiquity of, [9];
—with husked grains said to grow wild, [9];
—variation of, [7];
—irregularities in the flowers of, [9];
—persistence of varieties, [9];
—adaptation of, to climate, [9], [24];
—acclimatisation of, [24], [26];
—crossing of, [11], [16] (2);
—extinct Peruvian varieties of, [28].
MALAY fowl, [7].
MALAY Archipelago, horses of, [2];
—short-tailed cats of, [1];
—striped young wild pigs of, [3];
—ducks of, [8].
MALE, influence of, on the fecundated female, [11];
—supposed influence of, on offspring, [14].
MALE flowers, appearance of, among female flowers in maize, [9].
MALFORMATIONS, hereditary, [14].
MALINGIÉ-NOUEL, on sheep, [3];
—cross-breeding sheep, [14];
—English sheep in France, [21].
MALM, eyes of flat fish, [13].
Malva, fertilisation of, [11], [27].
Mamestra suasa, [18].
MAMMÆ, variable in number in the pig, [3];
—rudimentary, occasional full development of, in cows, [3], [24];
—four present in some sheep, [3];
—variable in number in rabbits, [4];
—latent functions of, in male animals, [13], [24].
MANGLES, Mr., annual varieties of the heartsease, [24].
MANTEGAZZA, abnormal growth of spur of cock, [27];
—on Pangenesis, [27].
MANTELL, Mr., taming of birds by the New Zealanders, [18].
MANU, domestic fowl noticed in the Institutes of, [7].
MANURE, effect of, on the fertility of plants, [18].
MANX cats, [1], [14].
MARCEL DE SERRES, fertility of the ostrich, [18].
MARIANNE Islands, varieties of Pandanus in, [22].
MARKHAM, GERVASE, on rabbits, [4], [20].
MARKHOR, probably one of the parents of the goat, [3].
MARQUAND, cattle of the Channel Islands, [3].
MARRIMPOEY, inheritance in the horse, [12].
MARROW, vegetable, [10].
MARRYATT, Capt., breeding of asses in Kentucky, [21].
MARSDEN, notice of Gallus giganteus, [7].
MARSHALL, Dr. W., on Gallus sonneratii, [7].
MARSHALL, Mr., voluntary selection of pasture by sheep, [3];
—adaptation of wheats to soil and climate, [9];
—“Dutch-buttocked” cattle, [12];
—segregation of herds of sheep, [16];
—advantage of change of soil to wheat and potatoes, [18];
—fashionable change in the horns of cattle, [20];
—sheep in Yorkshire, [21].
MARTENS, E. VON, on Achatinella, [13].
MARTIN, W. C. L., origin of the dog, [1];
—Egyptian dogs, [1];
—barking of a Mackenzie River dog, [1];
—African hounds in the Tower menagerie, [3];
—on dun horses and dappled asses, [2];
—breeds of the horse, [2];
—wild horses, [2];
—Syrian breeds of asses, [2];
—asses without stripes, [2];
—effects of cross-breeding on the female in dogs, [11];
—striped legs of mules, [13].
MARTINS, defective instincts of silkworms, [8].
MARTIUS, C., fruit-trees of Stockholm, [24].
MASON, W., bud-variation in the ash, [11].
MASTERS, Dr., on bud-variation and reversion, [11];
—potato-grafting, [11];
—on pollen within ovules, [27];
—reversion in the spiral-leaved weeping willow, [11];
—on peloric flowers, [13];
—on Opuntia, [23];
—pelorism in a clover, [26];
—position as a cause of pelorism, [26] (2).
MASTERS, Mr., persistence of varieties of peas, [9];
—reproduction of colour in hyacinths, [12];
—on hollyhocks, [16];
—selection of peas for seed, [20];
—on Hibiscus syriacus, [23];
—reversion by the terminal pea in the pod, [26].
MASTIFF, sculptured on an Assyrian monument, [1], [28];
—Tibetan, [1], [23].
MATTHEWS, PATRICK, on forest trees, [21].
Matthiola annua, [11] (2), [15].
Matthiola incana, [11] (2).
MAUCHAMP merino sheep, [3].
MAUDUYT, crossing of wolves and dogs in the Pyrenees, [1].
MAUND, Mr., crossed varieties of wheat, [17].
MAUPERTUIS, axiom of “least action,” [1].
MAURITIUS, importation of goats into, [3].
MAW, G., effects of change of climate, [24];
—correlation of contracted leaves and flowers in pelargoniums, [25] (2).
MAWZ, fertility of Brassica rapa, [18].
Maxillaria, self-fertilised capsules of, [17].
Maxillaria atro-rubens, fertilisation of, by M. squalens, [17].
MAXIMOWICZ, direct action of pollen, [11].
MAYERS, on gold-fish in China, [8].
MAYES, M., self-impotence in Amaryllis, [17].
MECKEL, on the number of digits, [12];
—correlation of abnormal muscles in the leg and arm, [25].
MEDUSÆ, development of, [27] (2).
MEEHAN, Mr., weeping peach, [12];
—effects of parasites, [23];
—comparison of European and American trees, [23].
Meles taxus, [18].
MELONS, [10] (2);
—mongrel supposed to be produced from a twin-seed, [11];
—crossing of varieties of, [11], [16], [17];
—inferiority of, in Roman times, [20];
—changes in, by culture and climate, [23];
—serpent, correlation of variations in, [25];
—analogous variations in, [26].
MEMBRANES, false, [24] (2).
MÉNÉTRIES, on the stomach of Strix grallaria, [24].
MENINGITIS, tubercular, inherited, [14].
MERRICK, potato-grafting, [11].
METAGENESIS, [27].
METAMORPHOSIS, [27].
METAMORPHOSIS and development, [27] (2).
METZGER, on the supposed species of wheat, [9] (2);
—tendency of wheat to vary, [9];
—variation of maize, [9] (2);
—cultivation of American maize in Europe, [9], [26];
—on cabbages, [9];
—acclimatisation of Spanish wheat in Germany, [12];
—advantage of change of soil to plants, [18];
—on rye, [22];
—cultivation of different kinds of wheat, [22].
MEXICO, dog from, with tan spots on the eyes, [1];
—colours of feral horses in, [2].
MEYEN, on seeding of bananas, [18].
MICE, grey and white, colours of, not blended by crossing, [15];
—rejection of bitter almonds by, [21];
—naked, [23].
MICHAUX, F., roan-coloured feral horses of Mexico, [2];
—origin of domestic turkey, [8];
—on raising peaches from seed, [10].
MICHEL, F., selection of horses in mediæval times, [20];
—horses preferred on account of slight characters, [20].
MICHELY, effects of food on caterpillars, [23];
—on Bombyx hesperus, [25].
MICROPHTHALMIA, associated with defective teeth, [25].
MIDDENS, Danish, remains of dogs in, [1], [28].
MIGNONETTE, [21], [24].
MILLET, [10].
MILLS, J., diminished fertility of mares when first turned out to grass, [18].
MILNE-EDWARDS, on the development of the crustacea, [27].
MILNE-EDWARDS, A., on a crustacean with a monstrous eye-peduncle, [27].
Milvus niger, [18].
Mimulus luteus, [17].
MINOR, W. C., gemmation and fission in annelids, [27].
Mirabilis, fertilisation of, [27];
—hybrids of, [17], [18], [22].
Mirabilis jalapa, [11] (2).
Mirabilis longiflora, [15].
Mirabilis vulgaris, [15].
Misocampus and Cecidomyia, [1].
MITCHELL, Dr., effects of the poison of the rattlesnake, [23].
MITFORD, Mr., notice of the breeding of horses by Erichthonius, [20].
MIVART, Mr., rudimentary organs, [24].
MOCCAS Court, weeping oak at, [12].
MOGFORD, horses poisoned by fool’s parsley, [25].
MÖLLER, L., effects of food on insects, [23].
MOLE, white, [25].
MOLL and Gayot, on cattle, [3], [15], [20].
MOLLUSCA, change in shells of, [23].
MONKE, Lady, culture of the pansy by, [10].
MONKEYS, rarely fertile in captivity, [18].
MONNIER, identity of summer and winter wheat, [9].
MONSTERS, double, [26] (2).
MONSTROSITIES, occurrence of, in domesticated animals and cultivated plants, [10], [22];
—due to persistence of embryonic conditions, [13];
—occurring by reversion, [13];
—a cause of sterility, [18];
—caused by injury to the embryo, [22].
MOOR, J. H., deterioration of the horse in Malasia, [2].
MOORCROFT, Mr., on Hasora wheat, [9];
—selection of white-tailed yaks, [20];
—melon of Kaschmir, [23];
—varieties of the apricot cultivated in Ladakh, [10];
—varieties of the walnut cultivated in Kaschmir, [27].
MOORE, Mr., on breeds of pigeons, [5] (2), [6] (3);
—on ground tumblers, [6].
MOORUK, fertility of, in captivity, [18].
MOQUIN-TANDON, original form of maize, [9];
—variety of the double columbine, [10];
—peloric flowers, [13];
—position as a cause of pelorism in flowers, [26];
—tendency of peloric flowers to become irregular, [14];
—on monstrosities, [22];
—correlation in the axis and appendages of plants, [25];
—fusion of homologous parts in plants, [26];
—on a bean with monstrous stipules and abortive leaflets, [26];
—conversion of parts of flowers, [27].
MORLOT, dogs of the Danish Middens, [1];
—sheep and horse of the Bronze period, [28].
Mormodes ignea, [13].
MOROCCO, estimation of pigeons in, [6].
MORREN, grafts of Abutilon, [11];
—on pelorism, [13];
—in Calceolaria, [26];
—non-coincidence of double flowers and variegated leaves, [18].
MORRIS, Mr., breeding of the kestrel in captivity, [18].
MORSE, Dr., digits of birds, [25].
MORTON, Lord, effect of fecundation by a quagga on an Arab mare, [11].
MORTON, Dr., origin of the dog, [1].
Morus alba, [10].
MOSCOW, rabbits of, [4] (2);
—effects of cold on pear-trees at, [24].
MOSSES, sterility in, [18];
—retrogressive metamorphosis in, [27].
MOSS-ROSE, probable origin of, from Rosa centifolia, [11];
—Provence roses produced from seeds of, [11].
MOSTO, Cada, on the introduction of rabbits into Porto Santo, [4].
MOT-MOT, mutilation of feathers inherited, [12].
MOTTLING of fruits and flowers, [11].
MOUNTAIN-ASH, [21].
MOUSE, Barbary, [18].
“MÖVEN-TAUBE,” [5].
MOWBRAY, Mr., on the eggs of game fowls, [7];
—early pugnacity of game cocks, [7];
—diminished fecundity of the pheasant in captivity, [18].
MOWBRAY, Mr., reciprocal fecundation of Passiflora alata and racemosa, [17].
MULATTOS, character of, [13].
MULBERRY, [10], [22].
MULE and hinny, differences in the, [14].
MULES, striped colouring of, [13];
—obstinacy of, [13];
—production of, among the Romans, [16];
—noticed in the Bible, [20].
MÜLLER, FRITZ, reproduction of orchids, [17];
—development of crustacea, [27];
—direct action of pollen, [11];
—self-sterile bignonia, [17].
MÜLLER, H., on the face and teeth in dogs, [1], [3], [26].
MÜLLER, J., tendency to variation, [22];
—atrophy of the optic nerve consequent on destruction of the eye, [24];
—on gemmation and fission, [27];
—identity of ovules and buds, [27];
—special affinities of the tissues, [27].
MÜLLER, MAX, antiquity of agriculture, [21].
MULTIPLICITY of origin of pigeons, hypotheses of, discussed, [6].
MUNIZ, F., on Niata cattle, [3].
MUNRO, R., on the fertilisation of orchids, [17];
—reproduction of Passiflora alata, [17];
—self-sterile Passiflora, [17].
“MURASSA” pigeon, [5].
MURIE, Dr., size of hybrids, [17].
MURPHY, J. J., the structure of the eye not producible by selection, [20].
Mus alexandrinus, [15] (2).
Musa sapientium, chinensis and cavendishii, [11].
Muscari comosum, [19], [24].
MUSCLES, effects of use on, [24].
MUSK duck, feral hybrid of, with the common duck, [6].
MUTILATIONS, inheritance or non-inheritance of, [12], [27] (2).
MYATT, on a five-leaved variety of the strawberry, [10].
MYOPIA, hereditary, [12].
MYRIAPODA, regeneration of lost parts in, [24], [27].
NAILS, growing on stumps of fingers, [27].
NAIS, scission of, [27].
NAMAQUAS, cattle of the, [3], [20].
NARCISSUS, double, becoming single in poor soil, [18].
NARVAEZ, on the cultivation of native plants in Florida, [9].
Nasua, sterility of, in captivity, [18].
“NATAS” or Niatas, a South American breed of cattle, [3].
NATHUSIUS, H. VON, on striped horses, [2];
—on the pigs of the Swiss lake-dwellings, [3];
—on the races of pigs, [3];
—convergence of character in highly-bred pigs, [3], [21];
—causes of changes in the form of the pig’s skull, [3] (2);
—changes in breeds of pigs by crossing, [3];
—change of form in the pig, [23];
—effects of disuse of parts in the pig, [24];
—period of gestation in the pig, [3];
—appendages to the jaw in pigs, [3];
—on Sus pliciceps, [3];
—period of gestation in sheep, [3];
—on Niata cattle, [3];
—on shorthorn cattle, [17];
—on interbreeding, [17];
—in the sheep, [17];
—in pigs, [17];
—unconscious selection in cattle and pigs, [20];
—variability of highly-selected races, [21].
NATO, P., on the Bizzarria orange, [11].
NATURAL selection, its general principles, [Introduction].
NATURE, sense in which the term is employed, [Introduction].
NAUDIN, supposed rules of transmission in crossing plants, [14];
—on the nature of hybrids, [13] (2);
—essences of the species in hybrids, [27] (2);
—reversion of hybrids, [13] (3);
—reversion in flowers by stripes and blotches, [13];
—hybrids of Linaria vulgaris and purpurea, [15];
—pelorism in Linaria, [13], [14];
—crossing of peloric Linaria with the normal form, [14];
—variability in Datura, [22];
—hybrids of Datura laevis and stramonium, [11];
—prepotency of transmission of Datura stramonium when crossed, [14];
—on the pollen of Mirabilis and of hybrids, [11];
—fertilisation of Mirabilis, [27];
—cultivated Cucurbitaceæ, [10] (2), [16];
—rudimentary tendrils in gourds, [24];
—dwarf Cucurbitæ, [25];
—relation between the size and number of the fruit in Cucurbita pepo, [26];
—analogous variation in Cucurbitæ, [22];
—acclimatisation of Cucurbitaceæ, [24];
—production of fruit by sterile hybrid Cucurbitaceæ, [18];
—on the melon, [10], [16], [23];
—incapacity of the cucumber to cross with other species, [10].
NECTARINE, [10];
—derived from the peach, [10] (2);
—hybrids of, [10];
—persistency of characters in seedling, [10];
—origin of, [10];
—produced on peach-trees, [10] (2);
—producing peaches, [10];
—variation in, [10] (2);
—bud-variation in, [11];
—glands in the leaves of the, [21];
—analogous variation in, [26].
NECTARY, variations of, in pansies, [10].
NEES, on changes in the odour of plants, [23].
“NEGRO” cat, [1].
NEGROES, polydactylism in, [12];
—selection of cattle practised by, [20].
NEOLITHIC period, domestication of Bos longifrons and primigenius in the, [3];
—cattle of the, distinct from the original species, [3];
—domestic goat in the, [3];
—cereals of the, [9].
NERVE, optic, atrophy of the, [24].
NEUBERT, potato-grafting, [11].
NEUMEISTER, on the Dutch and German pouter pigeons, [5];
—on the Jacobin pigeon, [5];
—duplication of the middle flight feather in pigeons, [5];
—on a peculiarly coloured breed of pigeons, “Staarhalsige Taube,” [5];
—fertility of hybrid pigeons, [6];
—mongrels of the trumpeter pigeon, [14];
—period of perfect plumage in pigeons, [14];
—advantage of crossing pigeons, [17].
NEURALGIA, hereditary, [14].
NEW ZEALAND, feral cats of, [1];
—cultivated plants of, [9].
NEWFOUNDLAND dog, modification of, in England, [1].
NEWMAN, E., sterility of Sphingidæ under certain conditions, [18].
NEWPORT, G., non-copulation of Vanessæ in confinement, [18];
—fertilisation of the ovule in batrachia, [27].
NEWT, polydactylism in the, [12].
NEWTON, A., absence of sexual distinctions in the Columbidæ, [5];
—production of a “black-shouldered” peahen among the ordinary kind, [8];
—on hybrid ducks, [18].
NGAMI, Lake, cattle of, [3].
“NIATA” cattle, [3];
—resemblance of, to Sivatherium, [3];
—prepotency of transmission of character by, [14].
“NICARD” rabbit, [4].
NICHOLSON, Dr., on the cats of Antigua, [1];
—on the sheep of Antigua, [3].
Nicotiana, crossing of varieties and species of, [3];
—prepotency of transmission of characters in species of, [14];
—contabescence of female organs in, [18].
Nicotiana glutinosa, [16].
NIEBUHR, on the heredity of mental characteristics in some Roman families, [14].
NIGHT-BLINDNESS, non-reversion to, [13].
NILSSON, Prof., on the barking of a young wolf, [1];
—parentage of European breeds of cattle, [3] (2);
—on Bos frontosus in Scania, [3].
NIND, Mr., on the dingo, [1].
“NISUS formativus,” [24] (2), [26].
NITZSCH, on the absence of the oil-gland in certain Columbæ, [5].
NON-INHERITANCE, causes of, [12].
“NONNAIN” pigeon, [5].
NORDMANN, dogs of Awhasie, [1].
NORMANDY, pigs of, with appendages under the jaw, [3].
NORWAY, striped ponies of, [2].
NOTT and Gliddon, on the origin of the dog, [1];
—mastiff represented on an Assyrian tomb, [1];
—on Egyptian dogs, [1];
—on the Hare Indian dog, [1].
Notylia, [17].
NOURISHMENT, excess of, a cause of variability, [22].
NUMBER, importance of, in selection, [21].
Numida ptilorhyncha, the original of the Guinea-fowl, [8].
NUN pigeon, [5];
—known to Aldrovandi, [6].
NUTMEG-TREE, [21].
OAK, weeping, [10], [12], [21];
—pyramidal, [10];
—Hessian, [10];
—late-leaved, [10];
—valueless as timber at the Cape of Good Hope, [23];
—changes in, dependent on age, [11];
—galls of the, [23].
OATS, wild, [9];
—in the Swiss lake-dwellings, [9].
OBERLIN, change of soil beneficial to the potato, [18].
ODART, Count, varieties of the vine, [10], [23];
—bud-variation in the vine, [11].
Œcidium, [23].
Œnothera biennis, bud-variation in, [11].
OGLE, Dr. J. W., inherited deficient phalanges, [12];
—resemblance of twins, [22] (2).
OIL-GLAND, absence of, in fantail pigeons, [5] (2).
OLDFIELD, Mr., estimation of European dogs among the natives of Australia, [20].
OLEANDER, stock affected by grafting in the, [11].
OLLIER, Dr., insertion of the periosteum of a dog beneath the skin of a rabbit, [27].
Oncidium, reproduction of, [17], [18].
ONIONS, crossing of, [15];
—white, liable to the attacks of fungi and disease, [21], [25].
Ophrys apifera, self-fertilisation of, [15];
—formation of pollen by a petal in, [27].
Opuntia leucotricha, [23].
ORANGE, [10];
—crossing of, [15];
—with the lemon, [11], [27];
—naturalisation of, in Italy, [24];
—variation of, in North Italy, [22];
—peculiar variety of, [25];
—bizzarria, [11];
—trifacial, [11].
ORCHIDS, reproduction of, [11] (2), [17].
ORFORD, Lord, crossing greyhounds with the bulldog, [1].
ORGANISMS, origin of, [Introduction].
ORGANISATION, advancement in, [Introduction].
ORGANS, rudimentary and aborted, [24];
—multiplication of abnormal, [27].
ORIOLE, assumptions of hen-plumage by a male in confinement, [18].
ORKNEY Islands, pigs of, [3];
—pigeons of, [6].
ORTHOPTERA, regeneration of hind legs in the, [24].
Orthosia munda, [18].
ORTON, R., on the effects of cross-breeding on the female, [11];
—on the Manx cat, [14];
—on mongrels from the silk fowl, [14];
—infertility of geese in Quito, [18].
OSBORNE, Dr., inherited mottling of the iris, [12].
OSPREY, preying on black fowls, [21].
OSTEN-SACKEN, Baron, on American oak-galls, [23].
OSTEOLOGICAL characters of pigs, [3] (4);
—of rabbits, [4];
—of pigeons, [5];
—of ducks, [8].
OSTRICH, diminished fertility of the, in captivity, [18].
OSTYAKS, selection of dogs by the, [20].
OTTER, [18].
“OTTER” sheep of Massachusetts, [3].
OUDE, feral humped cattle in, [3].
OUISTITI, breed in Europe, [18].
OVARY, variation of, in Cucurbita moschata, [10];
—development of, independently of pollen, [11].
Ovis montana, [3].
OVULES and buds, identity of nature of, [27].
OWEN, Capt., on stiff-haired cats at Mombas, [1].
OWEN, Prof. R., palæontological evidence as to the origin of dogs, [1];
—on the skull of the “Niata” cattle, [3];
—on fossil remains of rabbits, [3];
—on the significance of the brain, [4];
—on metagenesis, [27];
—theory of reproduction and parthenogenesis, [27].
OWL, eagle, breeding in captivity, [18].
OWL pigeon, [5];
—African, figured, [5];
—known in 1735, [6].
Oxalis, trimorphic species of, [27].
Oxalis rosea, [17].
OXLEY, Mr., on the nutmeg-tree, [21].
OYSTERS, differences in the shells of, [23].
PACA, sterility of the, in confinement, [4].
PACIFIC Islands, pigs of the, [3].
PADUA, earliest known flower-garden at, [20].
PADUAN fowl of Aldrovandi, [7].
Pæonia moutan, [20].
PÆONY-TREE, ancient cultivation of, in China, [20].
PAGET, on the Hungarian sheep-dog, [1].
PAGET, Sir J., inheritance of cancer, [12];
—hereditary elongation of hairs in the eyebrow, [12];
—regrowth of extra digits, [12];
—circumcision, [12];
—period of inheritance of cancer, [14];
—on Hydra, [24];
—on the healing of wounds, [24];
—on the reparation of bones, [24];
—growth of hair near inflamed surfaces or fractures, [24];
—on false membranes, [24];
—compensatory development of the kidney, [24];
—bronzed skin in disease of supra-renal capsules, [25];
—unity of growth and gemmation, [27];
—independence of the elements of the body, [27];
—affinity of the tissues for special organic substances, [27].
PALLAS, on the influence of domestication upon the sterility of intercrossed species, [1], [4], [6], [16];
—hypothesis that variability is wholly due to crossing, [4], [8], [22] (2);
—on the origin of the dog, [1];
—variation in dogs, [1];
—crossing of dog and jackal, [1];
—origin of domestic cats, [2];
—origin of Angora cat, [1];
—on wild horses, [2] (2);
—on Persian sheep, [3];
—on Siberian fat-tailed sheep, [23];
—on Chinese sheep, [24];
—on Crimean varieties of the vine, [10];
—on a grape with rudimentary seeds, [24];
—on feral musk-ducks, [13];
—sterility of Alpine plants in gardens, [18];
—selection of white-tailed yaks, [20].
PAMPAS, feral cattle on the, [3].
Pandanus, [22].
PANGENESIS, hypothesis of, [27].
Panicum, seeds of, used as food, [9];
—found in the Swiss lake-dwellings, [9].
PANSY, [10].
PAPPUS, abortion of the, in Carthamus, [24].
Paradoxurus, sterility of species of, in captivity, [18].
PARAGUAY, cats of, [1];
—cattle of, [3];
—horses of, [3];
—dogs of, [3];
—black-skinned domestic fowl of, [7].
PARALLEL variation, [26].
PARAMOS, woolly pigs of, [3].
PARASITES, liability to attacks of, dependent on colour, [21].
PARIAH dog, with crooked legs, [1];
—resembling the Indian wolf, [1].
PARISET, inheritance of handwriting, [13].
Paritium tricuspis, bud-variation, [11].
PARKER, W. K., number of vertebræ in fowls, [7].
PARKINSON, Mr., varieties of the hyacinth, [10].
PARKYNS, MANSFIELD, on Columba guinea, [6].
PARMENTIER, differences in the nidification of pigeons, [5];
—on white pigeons, [21].
PARROTS, general sterility of, in confinement, [18];
—alteration of plumage of, [23].
PARSNIP, reversion in, [13];
—influence of selection on, [20];
—experiments on, [23];
—wild, enlargement of roots of, by cultivation, [9].
PARTHENOGENESIS, [27] (2).
PARTRIDGE, sterility of, in captivity, [18].
PARTURITION, difficult, hereditary, [12].
Parus major, [21].
Passiflora, self-impotence in species of, [17] (2);
—contabescence of female organs in, [18].
Passiflora alata, fertility of, when grafted, [19].
PASTRANA, Julia, peculiarities in the hair and teeth of, [25].
PASTURE and climate, adaptation of breeds of sheep to, [3] (2).
PATAGONIA, crania of pigs from, [3].
PATAGONIAN rabbit, [4].
PATERSON, R., on the Arrindy silk-moth, [24].
PAUL, W., on the hyacinth, [10] (2);
—varieties of pelargoniums, [11];
—weakness of transmission in hollyhocks, [14];
—improvement of pelargoniums, [20].
Pavo cristatus and muticus, hybrids of, [8].
Pavo nigripennis, [8].
“PAVODOTTEN-TAUBE,” [5].
PEACH, [10];
—derived from the almond, [10];
—stones of, figured, [10];
—contrasted with almonds, [10];
—double-flowering, [10] (3);
—hybrids of, [10];
—persistency of races of, [10];
—trees producing nectarines, [10];
—variation in, [10] (2);
—bud-variation in, [11];
—pendulous, [12];
—variation by selection in, [20];
—peculiar disease of the, [21];
—glands on the leaves of the, [21];
—antiquity of the, [24];
—increased hardiness of the, [24];
—varieties of, adapted for forcing, [24];
—yellow-fleshed, liable to certain diseases, [25].
PEACH-ALMOND, [27].
PEAFOWL, origin of, [8];
—japanned or black-shouldered, [8];
—feral, in Jamaica, [6];
—comparative fertility of, in wild and tame states, [16], [22];
—white, [25].
PEARS, [10];
—bud-variation in, [11];
—reversion in seedling, [13];
—inferiority of, in Pliny’s time, [20];
—winter nelis, attacked by aphides, [21];
—soft-barked varieties of, attacked by wood-boring beetles, [21];
—origination of good varieties of, in woods, [22];
—Forelle, resistance of, to frost, [24].
PEAS, [9];
—origin of, [9];
—varieties of, [9];
—found in Swiss lake-dwellings, [9] (3);
—fruit and seeds figured, [9];
—persistency of varieties, [9];
—intercrossing of varieties, [9], [11];
—effect of crossing on the female organs in, [11];
—double-flowered, [18];
—maturity of, accelerated by selection, [20];
—varieties of, produced by selection, [20];
—thin-shelled, liable to the attacks of birds, [21];
—reversion of, by the terminal seed in the pod, [26].
PECCARY, breeding of the, in captivity, [18].
PEDIGREES of horses, cattle, greyhounds, game-cocks, and pigs, [12].
PEGU, cats of, [1];
—horses of, [2].
PELARGONIUMS, multiple origin of, [10];
—zones of, [10];
—bud-variation in, [11];
—variegation in, accompanied by dwarfing, [11];
—pelorism in, [18], [26];
—by reversion, [13];
—advantage of change of soil to, [18];
—improvement of, by selection, [20];
—scorching of, [21];
—numbers of, raised from seed, [21];
—effects of conditions of life on, [23];
—stove-variety of, [24];
—correlation of contracted leaves and flowers in, [25] (2).
Pelargonium fulgidum, conditions of fertility in, [18].
“PELONES,” a Columbian breed of cattle, [3], [6].
PELORIC flowers, tendency of, to acquire the normal form, [14];
—fertility or sterility of, [18] (2).
PELORIC races of Gloxinia speciosa and Antirrhinum majus, [10].
PELORISM, [13], [26] (2).
PELVIS, characters of, in rabbits, [4];
—in pigeons, [5];
—in fowls, [7];
—in ducks, [8].
PEMBROKE cattle, [3].
PENDULOUS trees, [10], [26];
—uncertainty of transmission of, [12] (2).
PENGUIN ducks, [8] (2);
—hybrid of the, with the Egyptian goose, [8].
PENNANT, production of wolf-like curs at Fochabers, [1];
—on the Duke of Queensberry’s wild cattle, [3].
Pennisetum, seeds of, used as food in the Punjab, [9].
Pennisetum distichum, seeds of, used as food in Central Africa, [9].
PERCIVAL, Mr., on inheritance in horses, [12];
—on horn-like processes in horses, [2].
Perdix rubra, occasional fertility of, in captivity, [18].
PERIOD of action of causes of variability, [22].
PERIOSTEUM of a dog, producing bone in a rabbit, [27].
PERIWINKLE, sterility of, in England, [19].
PERSIA, estimation of pigeons in, [6];
—carrier pigeon of, [5];
—tumbler pigeon of, [5];
—cats of, [1];
—sheep of, [3].
PERSISTENCE of colour in horses, [2];
—of generic peculiarities, [4].
PERU, antiquity of maize in, [9];
—peculiar potato from, [9];
—selection of wild animals practised by the Incas of, [20] (2).
“PERUCKEN-TAUBE,” [5].
PETALS, rudimentary, in cultivated plants, [24];
—producing pollen, [27].
PETUNIAS, multiple origin of, [10].
PEYRITSCH, Dr., vegetable teratology, [13].
“PFAUEN-TAUBE,” [5].
Phalænopsis, pelorism in, [26].
PHALANGES, deficiency of, [14].
Phaps chalcoptera, [26].
Phaseolus multiflorus, [24], [25].
Phaseolus vulgaris, [9], [24].
Phasianus pictus, [7].
Phasianus amherstiæ, [7].
PHEASANT, assumption of male plumage by the hen, [13];
—wildness of hybrids of, with the common fowl, [13];
—prepotency of the, over the fowl, [14];
—diminished fecundity of the, in captivity, [18].
PHEASANTS, golden and Lady Amherst’s, [7].
PHEASANT-FOWLS, [7].
PHILIPEAUX, regeneration of limbs in the salamander, [27].
PHILIPPAR, on the varieties of wheat, [9].
PHILIPPINE Islands, named breeds of game fowl in the, [7].
PHILLIPS, Mr., on bud-variation in the potato, [11].
Phlox, bud-variation by suckers in, [11].
PHTHISIS, affection of the fingers in, [25].
PHYLLOXERA, [10].
PICKERING, Dr., on the grunting voice of humped cattle, [3];
—occurrence of the head of a fowl in an ancient Egyptian procession, [7];
—seeding of ordinarily seedless fruits, [18];
—extinction of ancient Egyptian breeds of sheep and oxen, [28];
—on an ancient Peruvian gourd, [28].
PICOTEES, effect of conditions of life on, [23].
PICTET, A., oriental names of the pigeon, [6].
PICTET, Prof., origin of the dog, [1];
—on fossil oxen, [3].
PIEBALDS, probably due to reversion, [13].
PIÉTREMENT, M., on the ribs of horses, [2].
PIGEAUX, hybrids of the hare and rabbit, [18].
PIGEON à cravate, [5].
PIGEON bagadais, [5] (2).
PIGEON coquille, [5].
PIGEON cygne, [5].
PIGEON heurté, [5].
PIGEON pattu plongeur, [5].
PIGEON polonais, [5].
PIGEON romain, [5] (2).
PIGEON tambour, [5].
PIGEON turc, [5].
PIGEONS, origin of, [5] (2), [6];
—classified table of breeds of, [5];
—pouter, [5];
—carrier, [5];
—runt, [5];
—barbs, [5];
—fantail, [5];
—turbit and owl, [5];
—tumbler, [5];
—Indian frill-back, [5];
—Jacobin, [5];
—trumpeter, [5];
—other breeds of, [5];
—differences of, equal to generic, [5];
—individual variations of, [5];
—variability of peculiarities characteristic of breeds in, [5];
—sexual variability in, [5] (2);
—osteology of, [5];
—correlation of growth in, [5], [25];
—young of some varieties naked when hatched, [5], [25];
—effects of disuse in, [5];
—settling and roosting in trees, [6];
—floating in the Nile to drink, [6];
—dovecot, [6] (2);
—arguments for unity of origin of, [6];
—feral, in various places, [6], [13];
—unity of coloration in, [6];
—reversion of mongrel, to coloration of C. livia, [6];
—history of the cultivation of, [6];
—history of the principal races of, [6];
—mode of production of races of, [6];
—reversion in, [13];
—by age, [13];
—produced by crossing in, [13] (2);
—prepotency of transmission of characters in breeds of, [14] (2);
—sexual differences in some varieties of, [14];
—period of perfect plumage in, [14];
—effect of segregation on, [15];
—preferent pairing of, within the same breed, [16];
—fertility of, increased by domestication, [16], [18];
—effects of interbreeding and necessity of crossing, [17];
—indifference of, to change of climate, [18];
—selection of, [16], [20] (2);
—among the Romans, [20];
—unconscious selection of, [20] (2);
—facility of selection of, [21];
—white, liable to the attacks of hawks, [21];
—effects of disuse of parts in, [24];
—fed upon meat, [24];
—effect of first male upon the subsequent progeny of the female, [11];
—homology of the leg and wing feathers in, [25];
—union of two outer toes in feather-legged, [25];
—correlation of beak, limbs, tongue, and nostrils, [25];
—analogous variation in, [26] (2);
—permanence of breeds of, [28].
PIGS, of Swiss lake-dwellings, [3];
—types of, derived from Sus scrofa and Sus indicus, [3];
—Japanese (Sus pliciceps, Gray), figured, [3];
—of Pacific Islands, [3], [15];
—modifications of skull in, [3];
—length of intestines in, [3], [24];
—period of gestation of, [3];
—number of vertebræ and ribs in, [3];
—anomalous forms, [3] (2);
—development of tusks and bristles in, [3];
—striped young of, [3];
—reversion of feral, to wild type, [3] (2), [13] (2);
—production and changes of breeds of, by intercrossing, [3];
—effects produced by the first male upon the subsequent progeny of the female, [11];
—pedigrees of, [12];
—polydactylism in, [12];
—cross-reversion in, [13];
—hybrid, wildness of, [13];
—disappearance of tusks in male under domestication, [14];
—solid-hoofed, [28];
—crosses of, [15] (2);
—mutual fertility of all varieties of, [16];
—increased fertility by domestication, [16];
—ill effects of close interbreeding in, [17] (2);
—influence of selection on, [20];
—prejudice against certain colours in, [20], [21], [25];
—unconscious selection of, [20];
—black Virginian, [21], [25];
—similarity of the best breeds of, [21];
—change of form in, [23];
—effects of disuse of parts in, [24];
—ears of, [24];
—correlations in, [25];
—white buck-wheat injurious to, [25];
—tail of, grafted upon the back, [27];
—extinction of the older races of, [28].
PIMENTA, [15].
PIMPERNEL, [19].
PINE-APPLE, sterility and variability of the, [22].
PINK, Chinese, [25].
PINKS, bud-variation in, [11];
—improvement of, [20].
Pinus pumilio, mughus, and nana, varieties of P. sylvestris, [10].
Pinus sylvestris, [10], [24];
—hybrids of, with P. nigricans, [17].
PIORRY, on hereditary disease, [12], [14].
Pistacia lentiscus, [23].
Pistacia vera, [11].
PISTILS, rudimentary, in cultivated plants, [24].
PISTOR, sterility of some mongrel pigeons, [6];
—fertility of pigeons, [16].
Pisum arvense and sativum, [9].
PITYRIASIS versicolor, inheritance of, [14].
PLANCHON, G., on a fossil vine, [10];
—sterility of Jussiæa grandiflora in France, [18].
PLANE-TREE, variety of the, [10].
PLANTIGRADE carnivora, general sterility of the, in captivity, [18].
PLANTS, progress of cultivation of, [9] (2);
—cultivated, their geographical derivation, [9];
—crossing of, [15], [17];
—comparative fertility of wild and cultivated, [16];
—self-impotent, [17];
—dimorphic and trimorphic, [17];
—sterility of, from changed conditions, [18];
—from contabescence of anthers, [18] (2);
—from monstrosities, [9] (2);
—from doubling of the flowers, [18] (2);
—from seedless fruit, [18];
—from excessive development of vegetative organs, [18];
—influence of selection on, [20];
—variation by selection, in useful parts of, [20];
—variability of, [21];
—variability of, induced by crossing, [22];
—direct action of change of climate on, [23];
—change of period of vegetation in, [24];
—varieties of, suitable to different climates, [24];
—correlated variability of, [25];
—antiquity of races of, [28].
PLASTICITY, inheritance of, [21].
PLATEAU, F., on the vision of amphibious animals, [20].
Platessa flesus, , [13].
PLATO, notice of selection in breeding dogs by, [20].
PLICA polonica, [23].
PLINY, on the crossing of shepherd dogs with the wolf, [1];
—on Pyrrhus’ breed of cattle, [20];
—on the estimation of pigeons among the Romans, [6];
—pears described by, [20].
PLUM, [10];
—stones figured, [10];
—varieties of the, [10] (2), [20];
—bud-variation in the, [11];
—peculiar disease of the, [21];
—flower-buds of, destroyed by bullfinches, [21];
—purple-fruited, liable to certain diseases, [25].
PLUMAGE, inherited peculiarities of, in pigeons, [5] (2);
—sexual peculiarities of, in fowls, [7].
PLURALITY of races, Pouchet’s views on, [1].
Poa, seeds of, used as food, [9];
—species of, propagated by bulblets, [18].
PODOLIAN cattle, [3].
POINTERS, modification of, [1];
—crossed with the foxhound, [3].
POIS sans parchemin, [21].
POITEAU, origin of Cytisus adami, [11];
—origin of cultivated varieties of fruit-trees, [22].
POLISH fowl, [7] (6);
—skull figured, [7];
—section of skull figured, [7];
—development of protuberance of skull, [7];
—furculum figured, [7].
POLISH, or Himalayan rabbit, [4].
POLLEN, [27] (2);
—action of, [16];
—injurious action of, in some orchids, [17] (2);
—resistance of, to injurious treatment, [18];
—prepotency of, [19].
POLLOCK, Sir F., transmission of variegated leaves in Ballota nigra, [11];
—on local tendency to variegation, [23].
POLYANTHUS, [12].
POLYDACTYLISM, inheritance of, [12];
—significance of, [12].
PONIES, most frequent on islands and mountains, [2];
—Javanese, [2].
POOLE, Col., on striped Indian horses, [2] (2);
—on the young of Asinus indicus, [13].
POPLAR, Lombardy, [10].
PÖPPIG, on Cuban wild dogs, [1].
POPPY, found in the Swiss lake-dwellings, [9] (2);
—with the stamens converted into pistils, [10];
—differences of the, in different parts of India, [18];
—monstrous, fertility of, [18];
—black-seeded, antiquity of, [28].
PORCUPINE, breeding of, in captivity, [18].
PORCUPINE family, [12], [14].
Porphyrio, breeding of a species of, in captivity, [18].
PORTAL, on a peculiar hereditary affection of the eye, [12].
PORTO Santo, feral rabbits of, [4].
Portulaca oleracea, [23].
Potamochoerus penicillatus, [18].
POTATO, [9] (2);
—bud-variation by tubers in the, [11] (2);
—graft-hybrid of, by union of half-tubers, [11];
—individual self-impotence in the, [17];
—sterility of, [18];
—advantage of change of soil to the, [18].
POTATO, sweet, sterility of the, in China, [18];
—varieties of the, suited to different climates, [24].
POUCHET, M., his views on plurality of races, [1].
POUTER pigeons, [5];
—furculum figured, [5];
—history of, [6].
POWIS, Lord, experiments in crossing humped and English cattle, [3], [13].
POYNTER, Mr., on a graft-hybrid rose, [11].
PRAIRIE wolf, [1].
PRECOCITY of highly-improved breeds, [25].
PREPOTENCY of pollen, [19].
PREPOTENCY of transmission of character, [14], [19];
—in the Austrian emperors and some Roman families, [14];
—in cattle, [14] (2);
—in sheep, [14];
—in cats, [14];
—in pigeons, [14];
—in fowls, [14];
—in plants, [14];
—in a variety of the pumpkin, [10];
—in the jackal over the dog, [14];
—in the ass over the horse, [14];
—in the pheasant over the fowl, [14];
—in the penguin duck over the Egyptian goose, [14];
—discussion of the phenomena of, [14].
PRESCOTT, Mr., on the earliest known European flower-garden, [20].
PRESSURE, mechanical, a cause of modification, [26] (2).
PREVOST and Dumas, on the employment of several spermatozoids to fertilise one ovule, [27].
PREYER, Prof., on the effect of circumcision, [12].
PRICE, Mr., variations in the structure of the feet in horses, [2].
PRICHARD, Dr., on polydactylism in the negro, [12];
—on the Lambert family, [14];
—on an albino negro, [21];
—on Plica polonica, [23].
PRIMROSE, [28];
—double, rendered single by transplantation, [18].
Primula, intercrossing of species of, [10];
—contabescence in, [18];
—‘hose in hose,’ [10];
—with coloured calyces, sterility of, [18].
Primula sinensis, variations, [10];
—reciprocally dimorphic, [17].
Primula veris, [12], [16].
Primula vulgaris, [12], [16].
PRINCE, Mr., on the intercrossing of strawberries, [27].
PRINGSHEIM, on conjugation, [27].
Procyon, sterility of, in captivity, [18].
PROLIFICNESS, increased by domestication, [19].
PROTOZOA, reproduction of the, [27].
Prunus armeniaca, [10] (2).
Prunus avium, [10].
Prunus cerasus, [10] (2).
Prunus domestica, [10].
Prunus insititia, [10].
Prunus spinosa, [10].
PRUSSIA, wild horses in, [2].
Psittacus erithacus, [18].
Psittacus macoa, [18].
Psophia, general sterility of, in captivity, [18].
PTARMIGAN fowls, [7].
Pulex penetrans, [23].
PUMPKINS, [10].
PUNO ponies of the Cordillera, [2].
PUSEY, Mr., value of crossbred sheep, [17];
—preference of hares and rabbits for common rye, [21].
PUTSCHE and Vertuch, varieties of the potato, [9].
PUVIS, effects of foreign pollen on apples, [11];
—supposed non-variability of monotypic genera, [22].
Pyrrhula vulgaris, [21];
—assumption of the hen-plumage by the male, in confinement, [18].
PYRRHUS, his breed of cattle, [20].
Pyrus, fastigiate Chinese species of, [23].
Pyrus acerba, [10].
Pyrus aucuparia, [21].
Pyrus communis, [10], [11].
Pyrus malus, [10], [11].
Pyrus paradisiaca, [10].
Pyrus præcox, [10].
QUAGGA, previous impregnation by, [11].
QUATREFAGES, A. DE, on the burrowing of a bitch to litter, [1];
—selection in the silkworm, [8];
—development of the wings in the silk-moth, [8], [24];
—on varieties of the mulberry, [10];
—special raising of eggs of the silk-moth, [20];
—on disease of the silkworm, [21];
—on monstrosities in insects, [22], [27];
—on a change in the breeding season of the Egyptian goose, [24];
—fertilisation of the Teredo, [27];
—tendency to similarity in the best races, [21];
—on his “tourbillon vital,” [13];
—on the independent existence of the sexual elements, [27].
Quercus cerris, [10].
Quercus robur and pedunculata, hybrids of, [17].
QUINCE, pears grafted on the, [22].
RABBITS, domestic, their origin, [4];
—of Mount Sinai and Algeria, [4];
—breeds of, [4];
—Himalayan, Chinese, Polish, or Russian, [4], [15];
—feral, [4];
—of Jamaica, [4];
—of the Falkland Islands, [4];
—of Porto Santo, [4], [16], [23];
—osteological characters of, [4];
—discussion of modifications in, [4], [5];
—one-eared, transmission of peculiarity of, [12];
—reversion in feral, [13];
—in the Himalayan, [13];
—crossing of white and coloured Angora, [15];
—comparative fertility of wild and tame, [16];
—falsified experiments in interbreeding of, [17];
—high-bred, often bad breeders, [17];
—selection of, [20];
—white, liable to destruction, [21];
—effects of disuse of parts in, [24];
—skull of, affected by drooping ears, [24];
—length of intestines in, [24];
—correlation of ears and skull in, [25] (2);
—variations in skull of, [26];
—periosteum of a dog producing bone in, [27].
RACEHORSE, origin of, [2].
RACES, modification and formation of, by crossing, [3];
—natural and artificial, [21];
—Pouchet’s views on plurality of, [Introduction];
—of pigeons, [6].
RADCLYFFE, W. F., effect of climate and soil on strawberries, [10];
—constitutional differences in roses, [10].
RADISHES, [9];
—crossing of, [15];
—varieties of, [21].
RADLKOFER, retrogressive metamorphosis in mosses and algæ, [27].
RAFARIN, M., bud-variation and reversion, [11].
RAFFLES, Sir STAMFORD, on the crossing of Javanese cattle with Bos sondaicus, [20].
RAM, goat-like, from the Cape of Good Hope, [14].
RAMU, M., on appendages to throat of goat, [3].
RANCHIN, heredity of diseases, [12].
RANGE of gallinaceous birds on the Himalaya, [7].
RANKE, on the effects of use and disuse of organs, [24].
Ranunculus ficaria, [18].
Ranunculus repens, [18].
RAPE, [9].
Raphanus caudatus, [9].
Raphanus raphanistrum, [9].
Raphanus sativus, [26].
RASPBERRY, yellow-fruited, [21].
RATTLESNAKE, experiments with poison of the, [23].
RAVEN, stomach of, affected by vegetable diet, [24].
RAWSON, A., self-impotence in hybrids of Gladiolus, [17] (2).
RÉ, COMTE, on the assumption of a yellow colour by all varieties of maize, [9].
RÉAUMUR, effect of confinement upon the cock, [13];
—fertility of fowls in most climates, [18].
REED, Mr., atrophy of the limbs of rabbits, consequent on the destruction of their nerves, [24].
REGENERATION of amputated parts in man, [12];
—in the human embryo, [27];
—in the lower vertebrata, insects, and myriapoda, [27].
RE-GROWTH of amputated joints, [27].
REGNIER, early cultivation of the cabbage by the Celts, [9];
—selection practised by the Celts, [20].
REINDEER, individuals recognised by the Laplanders, [22].
REISSEK, experiments in crossing Cytisus purpureus and laburnum, [11];
—modification of a Thesium by Œcidium, [23].
RELATIONS, characters of reproduced in children, [13].
RENGGER, occurrence of jaguars with crooked legs in Paraguay, [1];
—naked dogs of Paraguay, [1] (2), [15], [16];
—feral dogs of La Plata, [1];
—on the aguara, [1];
—cats of Paraguay, [1], [15], [18];
—dogs of Paraguay, [15];
—feral pigs of Buenos Ayres, [3];
—on the refusal of wild animals to breed in captivity, [18];
—on Dicotyles labiatus, [18];
—sterility of plantigrade carnivora in captivity, [18];
—on Cavia aperea, [18];
—sterility of Cebus azarae in captivity, [18];
—abortions produced by wild animals in captivity, [18].
REPRODUCTION, sexual and asexual, contrasted, [27];
—unity of forms of, [27];
—antagonism of, to growth, [27].
Reseda odorata, self-sterility of, [17], [21].
RETINITIS, pigmentary, in deaf-mutes, [25].
REUTER, Herr, potato-grafting, [11].
REVERSION, [13] (2), [27] (4);
—in pigeons, [13];
—in cattle, [13];
—in sheep, [13];
—in fowls, [13];
—in the heartsease, [13];
—in vegetables, [13];
—in feral animals and plants, [13];
—to characters derived from a previous cross in man, dogs, pigeons, pigs, and fowls, [13];
—in hybrids, [13];
—by bud-propagation in plants, [13];
—by age in fowls, cattle, etc., [13] (2);
—partial, from an injury, [13];
—caused by crossing, [13];
—explained by latent characters, [13];
—producing monstrosities, [13];
—producing peloric flowers, [13];
—of feral pigs to the wild type, [3] (2);
—of supposed feral rabbits to the wild type, [4] (3);
—of pigeons, in coloration, when crossed, [6];
—in fowls, [7];
—in the silkworm, [8];
—in the pansy, [10];
—in a pelargonium, [11];
—in Chrysanthemums, [11];
—of varieties of the China rose in St. Domingo, [11];
—by buds in pinks and carnations, [11];
—of laciniated varieties of trees to the normal form, [11];
—in variegated leaves of plants, [11];
—in tulips, [11];
—of suckers of the seedless barberry to the common form, [11];
—by buds in hybrids of Tropæolum, [11];
—in plants, [11];
—of crossed peloric snapdragons, [14];
—analogous variations due to, [26].
RHINOCEROS, breeding in captivity in India, [18].
Rhododendron, hybrid, [22].
Rhododendron ciliatum, [23].
Rhododendron dalhousiæ, effect of pollen of R. nuttallii upon, [11].
Ribes grossularia, [10] (2).
Ribes rubrum, [11].
RIBS, number and characters of, in fowls, [7];
—characters of, in ducks, [8] (2).
RICE, imperial, of China, [20];
—Indian varieties of, [22];
—variety of, not requiring water, [24].
RICHARDSON, H. D., on jaw-appendages in Irish pigs, [3];
—management of pigs in China, [3];
—occurrence of striped young in Westphalian pigs, [3];
—on crossing pigs, [15];
—on interbreeding pigs, [17];
—on selection in pigs, [20].
RICHARDSON, Sir John, observations on the resemblance between North American dogs and wolves, [1] (2);
—on the burrowing of wolves, [1];
—on the broad feet of dogs, wolves, and foxes in North America, [1];
—on North American horses scraping away the snow, [2].
Ricinus, annual in England, [24].
RIEDEL, Dr., on the “Bagadotte” pigeon, [5];
—on the Jacobin pigeon, [5];
—fertility of hybrid pigeons, [6];
—circumcision, [12].
RILEY, on Phylloxera, [10].
RINDERPEST, [27].
RINTOUL, Mr., potato-grafting, [11].
RISSO, on varieties of the orange, [10], [24], [25].
RIVERS, Lord, on the selection of greyhounds, [21].
RIVERS, Mr., persistency of characters in seedling potatoes, [9];
—on the peach, [10] (2);
—persistency of races in the peach and nectarine, [10] (2);
—connection between the peach and the nectarine, [10];
—persistency of character in seedling apricots, [10];
—origin of the plum, [10];
—seedling varieties of the plum, [10];
—persistency of character in seedling plums, [10];
—bud-variation in the plum, [11];
—plum attacked by bullfinches, [21];
—seedling apples with surface-roots, [10];
—variety of the apple found in a wood, [22];
—on roses, [10] (2);
—bud-variation in roses, [11];
—production of Provence roses from seeds of the moss-rose, [11];
—effect produced by grafting on the stock in jessamine, [11];
—in the ash, [11];
—on grafted hazels, [11];
—hybridisation of a weeping thorn, [12];
—experiments with the seed of the weeping elm and ash, [12];
—variety of the cherry with curled petals, [21].
RIVIÈRE, reproduction of Oncidium cavendishianum, [17].
ROBERTS, Mr., on inheritance in the horse, [12].
ROBERTSON, Mr., on glandular-leaved peaches, [10].
ROBINET, on the silkworm, [8], [20].
Robinia, [23].
ROBSON, Mr., deficiencies of half-bred horses, [12].
ROBSON, Mr., on the advantage of change of soil to plants, [18] (2);
—on the growth of the verbena, [23];
—on broccoli, [24].
ROCK pigeon, measurements of the, [5];
—figured, [5].
RODENTS, sterility of, in captivity, [18].
Rodriguezia, [17] (2).
RODWELL, J., poisoning of horses by mildewed tares, [25].
ROHILCUND, feral humped cattle in, [3].
ROLLE, F., on the history of the peach, [24].
ROLLER-PIGEONS, Dutch, [5].
ROLLESTON, Prof., inherited effects of injuries, [12];
—incisor teeth affected in form in cases of pulmonary tubercle, [25].
ROMANES on sternum of the fowl, [7];
—rudimentary organs, [24].
ROMANS, estimation of pigeons by, [6];
—breeds of fowls possessed by, [7] (2).
ROOKS, pied, [14].
Rosa, cultivated species of, [10].
Rosa devoniensis, graft-hybrid produced by, on the white Banksian rose, [11].
Rosa indica and centifolia, fertile hybrids of, [10].
Rosa spinosissima, history of the culture of, [10].
ROSELLINI, on Egyptian dogs, [1].
ROSES, [10] (2);
—origin of, [10];
—bud-variation in, [11];
—Scotch, doubled by selection, [20];
—continuous variation of, [21];
—effect of seasonal conditions on, [23];
—noisette, [20];
—galls of, [23].
ROSS, Dr., on Pangenesis, [27] (2).
ROUENNAIS, rabbit, [4].
ROUJOU, polydactylism, and arrested development, [12].
ROULIN, on the dogs of Juan Fernandez, [1];
—on South American cats, [1];
—striped young pigs, [3];
—feral pigs in South America, [3], [13];
—on Columbian cattle, [3], [20], [21];
—effects of heat on the hides of cattle in South America, [3];
—fleece of sheep in the hot valleys of the Cordilleras, [3];
—diminished fertility of these sheep, [18];
—on black-boned South American fowls, [7];
—variation of the guinea-fowl in tropical America, [8];
—frequency of striped legs in mules, [13];
—geese in Bogota, [18];
—sterility of fowls introduced into Bolivia, [18].
ROY, M., on a variety of Magnolia grandiflora, [24].
ROYLE, Dr., Indian varieties of the mulberry, [10];
—on Agave vivipara, [18];
—variety of rice not requiring irrigation, [24];
—sheep from the Cape in India, [24].
Rubus, pollen of, [22].
RUDIMENTARY organs, [1], [24].
RUFZ DE LAVISON, extinction of breeds of dogs in France, [28].
RUMINANTS, general fertility of, in captivity, [18].
RUMPLESS fowls, [7].
RUNTS, [5];
—history of, [6];
—lower jaws and skull figured, [5].
RUSSELL, Lord A., spiegelcarpe, [21].
RUSSIAN or Himalayan rabbit, [4].
RUTIMEYER, Prof., dogs of the Neolithic period, [1];
—horses of Swiss lake-dwellings, [2];
—diversity of early domesticated horses, [2];
—pigs of the Swiss lake-dwellings, [3] (2);
—on humped cattle, [3];
—parentage of European breeds of cattle, [3], [28];
—on “Niata” cattle, [3];
—sheep of the Swiss lake-dwellings, [3], [28];
—goats of the Swiss lake-dwellings, [3];
—absence of fowls in the Swiss lake-dwellings, [7];
—on crossing cattle, [15];
—differences in the bones of wild and domesticated animals, [23];
—decrease in size of wild European animals, [28].
RYE, wild, De Candolle’s observations on, [9];
—found in the Swiss lake-dwellings, [9];
—common, preferred by hares and rabbits, [21];
—less variable than other cultivated plants, [22].
SABINE, Mr., on the cultivation of Rosa spinosissima, [10];
—on the cultivation of the dahlia, [10] (2), [22];
—effect of foreign pollen on the seed-vessel in Amaryllis vittata, [11].
ST. ANGE, influence of the pelvis on the shape of the kidneys in birds, [26].
ST. DOMINGO, wild dogs of, [1];
—bud-variation of dahlias in, [11].
ST. HILAIRE, AUG., milk furnished by cows in South America, [24];
—husked form of maize, [9].
ST. JOHN, C., feral cats in Scotland, [1];
—taming of wild ducks, [8].
ST. VALÉRY apple, singular structure of the, [10];
—artificial fecundation of the, [11].
ST. VITUS’ Dance, period of appearance of, [14].
SACHS, Prof., flow of sap, [24].
SAGERET, origin and varieties of the cherry, [10] (2);
—origin of varieties of the apple, [10];
—incapacity of the cucumber for crossing with other species, [10];
—varieties of the melon, [10];
—supposed twin-mongrel melon, [11];
—crossing melons, [16], [17];
—on gourds, [16];
—effects of selection in enlarging fruit, [20];
—on the tendency to depart from type, [21];
—variation of plants in particular soils, [23].
SALAMANDER, experiments on the, [24], [27] (2);
—regeneration of lost parts in the, [27].
Salamandra cristata, polydactylism in, [12].
SALISBURY, Mr., on the production of nectarines by peach-trees, [10];
—on the dahlia, [10] (2).
Salix, intercrossing of species of, [10].
Salix humilis, galls of, [23] (2).
SALLÉ, feral guinea-fowl in St. Domingo, [8].
SALMON, early breeding of male, [27].
SALTER, Mr., on bud-variation in pelargoniums, [11];
—in the Chrysanthemum, [11];
—transmission of variegated leaves by seed, [11];
—bud-variation by suckers in Phlox, [11];
—application of selection to bud-varieties of plants, [11];
—accumulative effect of changed conditions of life, [22];
—on the variegation of strawberry leaves, [23];
—on pollen within ovules, [27].
SALTER, S. J., hybrids of Gallus sonneratii and the common fowl, [7];
—crossing of races or species of rats, [15].
SALVIN, habits of the jackal, [1];
—mutilation inherited in mot-mot, [12].
SAMESREUTHER, on inheritance in cattle, [12].
SANDFORD. See DAWKINS.
SANSON, M., origin of the horse, [2];
—lumbar vertebra of pigs, [3].
SAP, ascent of the, [24].
Saponaria calabrica, [12].
SAPORTA, on Pistacia, [11].
SARDINIA, ponies of, [2].
SARS, on the development of the hydroida, [27].
SATIATION of the stigma, [11] (2).
Saturnia pyri, sterility of, in confinement, [18].
SAUL, on the management of prize gooseberries, [10].
SAUVIGNY, varieties of the gold-fish, [8].
SAVAGES, their indiscriminate use of plants as food, [9];
—fondness of, for taming animals, [18].
SAVI, effect of foreign pollen on maize, [11].
Saxifraga geum, [18].
SAYZID MOHAMMED MUSARI, on carrier-pigeons, [5];
—on a pigeon which utters the sound “Yahu,” [5].
SCANDEROONS (pigeons), [5] (2).
SCANIA, remains of Bos frontosus found in, [3].
SCAPULA, characters of, in rabbits, [4];
—in fowls, [7];
—in pigeons, [5];
—alteration of, by disuse, in pigeons, [5].
SCARLET fever, [23].
SCHAAFFHAUSEN on the horses represented in Greek statues, [20].
SCHLEIDEN, excess of nourishment a cause of variability, [22].
SCHMERLING, Dr., varieties of the dog found in a cave, [1].
SCHOMBURGK, Sir R., on the dogs of Indians of Guiana, [1] (2), [20];
—on the musk duck, [6];
—bud-variation in the banana, [11];
—reversion of varieties of the China rose in St. Domingo, [11];
—sterility of tame parrots in Guiana, [18];
—on Dendrocygna viduata, [18];
—selection of fowls in Guiana, [20].
SCHREIBERS, on Proteus, [24].
SCHÜTZE on the Torfschwein, [3].
Sciuropterus volucella, [18].
Sciurus palmarum and cinerea, [18].
SCLATER, P. L., on Asinus tæniopus, [2], [13];
—on Asinus indicus, [13];
—striped character of young wild pigs, [3];
—osteology of Gallinula nesiotis, [8];
—on the black-shouldered peacock, [8];
—animals breeding in Zoological Gardens, [18];
—birds breeding in Zoological Gardens, [18];
—on the breeding of birds in captivity, [18] (2).
SCOTCH fir, local variation of, [10].
SCOTCH kail and cabbage, cross between, [15].
SCOTT, JOHN, irregularities in the sex of the flowers of maize, [9];
—bud-variation in Imatophylium miniatum, [11];
—crossing of species of Verbascum, [16] (2);
—self-sterility of Verbascum, [17];
—experiments on crossing Primulæ, [16];
—reproduction of orchids, [17];
—fertility of Oncidium divaricatum, [18];
—acclimatisation of the sweet pea in India, [24];
—number of seeds in Acropera and Gongora, [27].
SCROPE, on the Scotch deerhound, [14], [17].
SCUDDER, Dr., on regrowth, [27].
SEBRIGHT, Sir John, effects of close interbreeding in dogs, [20];
—care taken by, in selection of fowls, [20].
Secale cereale, [22].
SEDGWICK, W., effects of crossing on the female, [11];
—on the “Porcupine man,” [12];
—on hereditary diseases, [12];
—hereditary affections of the eye, [12], [14];
—inheritance of polydactylism and anomalies of the extremities, [12] (2);
—morbid uniformity in the same family, [12];
—on deaf-mutes, [12];
—inheritance of injury to the eye, [12];
—atavism in diseases and anomalies of structure, [13];
—non-reversion to night-blindness, [13];
—sexual limitation of the transmission of peculiarities in man, [14] (2);
—on the effects of hard-drinking, [23];
—inherited baldness with deficiency of teeth, [25] (2);
—occurrence of a molar tooth in place of an incisor, [27];
—diseases occurring in alternate generations, [27].
SEDILLOT, on the removal of portions of bone, [24].
SEEDS, early selection of, [20];
—rudimentary, in grapes, [24];
—relative position of, in the capsule, [26].
SEEDS and buds, close analogies of, [11].
SEEMANN, B., crossing of the wolf and Esquimaux dogs, [1].
SEGREGATION of characters, [11] (2).
SELBY, P. J., on the bud-destroying habits of the bullfinch, [21].
SELECTION, [20];
—methodical, [6], [20], [21];
—by the ancients and semi-civilised people, [20];
—of trifling characters, [20];
—unconscious, [6] (2);
—effects of, shown by differences in most valued parts, [20];
—produced by accumulation of variability, [20];
—natural, as affecting domestic productions, [19], [21];
—as the origin of species, genera, and other groups, [28];
—circumstances favourable to, [21];
—tendency of, towards extremes, [21];
—possible limit of, [21];
—influence of time on, [21] (2);
—summary of subject, [21] (2);
—effects of, in modifying breeds of cattle, [3];
—in preserving the purity of breeds of sheep, [3] (2);
—in producing varieties of pigeons, [6];
—in breeding fowls, [7] (2);
—in the goose, [8];
—in the canary, [8];
—in the gold-fish, [8];
—in the silkworm, [8] (2);
—contrasted in cabbages and cereals, [9];
—in white mulberry, [10];
—on gooseberries, [10];
—applied to wheat, [9] (2);
—exemplified in carrots, etc., [9];
—in potato, [9];
—in the melon, [10];
—in flowering plants, [10];
—in the hyacinth, [10];
—applied to bud-varieties of plants, [11];
—illustrations of, [28].
SELECTION, sexual, [14].
SELF-IMPOTENCE in plants, [17];
—in individual plants, [17];
—of hybrids, [19].
SELWYN, Mr., on the Dingo, [1].
SELYS-LONGCHAMPS, on hybrid ducks, [6], [13], [18];
—hybrid of the hook-billed duck and Egyptian goose, [8].
SERINGE, on the St. Valéry apple, [10].
SERPENT melon, [10], [25].
SERRES, OLIVIER DE, wild poultry in Guiana, [7].
SESAMUM, white-seeded, antiquity of the, [28].
Setaria, found in the Swiss lake-dwellings, [9].
SETTEGAST, sheep poisoned by buckwheat, [25].
SETTERS, degeneration of, in India, [1];
—Youatt’s remarks on, [1].
SEX, secondary characters of, latent, [13] (2);
—of parents, influence of, on hybrids, [22].
SEXUAL characters, sometimes lost in domestication, [14].
SEXUAL limitation of characters, [14].
SEXUAL peculiarities, induced by domestication in sheep, [3];
—in fowls, [7];
—transfer of, [7].
SEXUAL variability in pigeons, [5] (2).
SEXUAL selection, [14].
SHADDOCK, [10].
SHAILER, Mr., on the moss-rose, [11].
SHAN ponies, striped, [2].
SHANGHAI fowls, [7].
SHANGHAI sheep, their fecundity, [3].
SHEEP, disputed origin of, [3];
—early domestication of, [3];
—large-tailed, [3] (2), [23];
—variations in horns, mammæ, and other characters of, [3];
—sexual characters of, induced by domestication, [3];
—adaptation of, to climate and pasture, [3] (2);
—periods of gestation of, [3];
—effect of heat on the fleece of, [3];
—effect of selection on, [3];
—“ancon” or “otter” breeds of, [3];
—“Mauchamp-merino,” [3] (2);
—cross of German and merino, [15];
—black, of the Tarentino, [21];
—Karakool, [23];
—Jaffna, with callosities on the knees, [24];
—Chinese, [24];
—Danish, of the Bronze period, [28];
—polydactylism in, [12];
—occasional production of horns in hornless breeds of, [13];
—reversion of colour in, [13];
—influence of male, on offspring, [14];
—sexual differences in, [14];
—influence of crossing or segregation on, [15] (2), [16] (2);
—interbreeding of, [17] (2);
—effect of nourishment on the fertility of, [16];
—value of, crossbred, [17];
—diminished fertility of, under certain conditions, [18];
—unconscious selection of, [20];
—natural selection in breeds of, [21] (2);
—reduction of bones in, [21];
—individual differences of, [22];
—local changes in the fleece of, in England, [23];
—partial degeneration of, in Australia, [23];
—correlation of horns and fleece in, [25];
—feeding on flesh, [24];
—acclimatisation of, [24];
—mountain, resistance of, to severe weather, [24];
—white, poisoned by Hypericum crispum, [25].
SHEEP dogs, resembling wolves, [1];
—mutilated tail inherited, [12].
SHELLS, sinistral and dextral, [13].
SHIRLEY, E. P., on the fallow-deer, [16], [17].
SHIRREFF Mr., new varieties of wheat, [9] (2);
—on crossing wheat, [16];
—variability of wheat, [11];
—continuous variation of wheat, [21].
SHORT, D., hybrids of the domestic cat and Felis ornata, [1].
SIAM, cats of, [1];
—horses of, [2].
SIBERIA, northern range of wild horses in, [2].
SICHEL, J., on the deafness of white cats with blue eyes, [25].
SIDNEY, S., on the pedigrees of pigs, [12];
—on cross-reversion in pigs, [13];
—period of gestation in the pig, [3];
—production of breeds of pigs by intercrossing, [3], [15];
—fertility of the pig, [16];
—effects of interbreeding on pigs, [17];
—on the colours of pigs, [20], [21].
SIEBOLD, on the sweet potato, [21].
SIEBOLD, CARL VON, on parthenogenesis, [27].
Silene, contabescence in, [18].
SILK FOWLS, [7], [14] (2).
SILK-MOTH, Arrindy, [24] (23);
—Tarroo, [18].
SILK-MOTHS, [8];
—domesticated, species of, [8];
—history of, [8];
—causes of modification in, [8];
—differences presented by, [8];
—crossing of, [15];
—disease in, [21];
—effects of disuse of parts in, [24];
—selection practised with, [20] (2);
—variation of, [21];
—parthenogenesis in, [27].
SILKWORMS, variations of, [8];
—yielding white cocoons, less liable to disease, [25].
SILVER-GREY rabbit, [4] (3).
SIMON, on the raising of eggs of the silk-moth in China, [20].
SIMONDS, J. B., period of maturity in various breeds of cattle, [3];
—differences in the periods of dentition in sheep, [3];
—on the teeth in cattle, sheep, etc., [25];
—on the breeding of superior rams, [20].
SIMPSON, Sir J., regenerative power of the human embryo, [27].
Siredon, breeding in the branchiferous stage, [27].
SISKIN, breeding in captivity, [18].
Sivatherium, resemblance of the, to Niata cattle, [3].
SIZE, difference of, an obstacle to crossing, [16].
SKIN, and its appendages, homologous, [25];
—hereditary affections of the, [14].
SKIRVING, R. S., on pigeons settling on trees in Egypt, [6].
SKULL, characters of the, in breeds of dogs, [1];
—in breeds of pigs, [3];
—in rabbits, [4] (2);
—in breeds of pigeons, [5] (2);
—in breeds of fowls, [7];
—in ducks, [8] (2).
SKULL and horns, correlation of the, [25].
SKYLARK, [18].
SLEEMAN, on the cheetah, [18].
SLOE, [10].
SMALL-POX, [27].
SMITER (pigeon), [5].
SMITH, Sir A., on Caffrarian cattle, [3];
—on the use of numerous plants as food in South Africa, [9].
SMITH, Colonel HAMILTON, on the odour of the jackal, [1];
—on the origin of the dog, [1];
—wild dogs in St. Domingo, [1];
—on the Thibet mastiff and the alco, [1];
—development of the fifth toe in the hind feet of mastiffs, [1];
—differences in the skull of dogs, [1];
—history of the pointer, [1];
—on the ears of the dog, [24];
—on the breeds of horses, [2];
—origin of the horse, [2];
—dappling of horses, [2];
—striped horses in Spain, [2];
—original colour of the horse, [2];
—on horses scraping away snow, [2];
—on Asinus hemionus, [13];
—feral pigs of Jamaica, [3] (2).
SMITH, Sir J. E., production of nectarines and peaches by the same tree, [10];
—on Viola amoena, [10];
—sterility of Vinca minor in England, [18].
SMITH, J., development of the ovary in Bonatea speciosa by irritation of the stigma, [11].
SMITH, N. H., influence of the bull “Favourite” on the breed of Shorthorn cattle, [14].
SMITH, W., on the intercrossing of strawberries, [10].
SNAKE-RAT, [15] (2).
SNAKES, form of the viscera in, [26].
SNAPDRAGON, bud-variation in, [11];
—non-inheritance of colour in, [12];
—peloric, crossed with the normal form, [14], [15];
—asymmetrical variation of the, [25].
SOIL, adaptation of plums to, [10];
—influence of, on the zones of pelargoniums, [10];
—on roses, [10];
—on the variegation of leaves, [11];
—advantages of change of, [18].
SOIL and climate, effects of, on strawberries, [10].
Solanum, non-intercrossing of species of, [15].
Solanum tuberosum, [9] (2), [11].
SOLID-HOOFED pigs,[3].
SOLOMON, his stud of horses, [2].
SOMERVILLE, Lord, on the fleece of Merino sheep, [3];
—on crossing sheep, [17];
—on selection of sheep, [20];
—diminished fertility of Merino sheep brought from Spain, [18].
SOOTY fowls, [7] (2).
Sorghum, [10].
SOTO, FERDINAND DE, on the cultivation of native plants in Florida, [9].
SPAIN, hawthorn monogynous in, [10].
SPALLANZANI, on feral rabbits in Lipari, [4];
—experiments on salamanders, [24], [27] (2);
—experiments in feeding a pigeon with meat, [24].
SPANIELS, in India, [1];
—King Charles’s, [1];
—degeneration of, caused by interbreeding, [17].
SPANISH fowls, [7] (3);
—figured, [7];
—early development of sexual characters in, [7];
—furculum of, figured, [7].
SPECIES, difficulty of distinguishing from varieties, [Introduction];
—conversion of varieties into, [Introduction];
—origin of, by natural selection, [28];
—by mutual sterility of varieties, [19].
SPENCER, Lord, on selection in breeding, [20].
SPENCER, HERBERT, on the “survival of the fittest,” [Introduction];
—increase of fertility by domestication, [16];
—on life, [18], [19];
—changes produced by external conditions, [23];
—effects of use on organs, [24];
—ascent of the sap in trees, [24];
—correlation exemplified in the Irish elk, [25] (2);
—on “physiological units,” [27];
—antagonism of growth and reproduction, [27].
SPERMATOPHORES of the cephalopoda, [27].
SPERMATOZOIDS, [27] (2).
SPHINGIDÆ, sterility of, in captivity, [18].
SPINOLA, on the injurious effect produced by flowering buckwheat on white pigs, [25].
SPITZ dog, [1].
SPOONER, W. C., cross-breeding of sheep, [3], [15] (2), [17];
—on the effects of crossing, [15] (2);
—on crossing cattle, [17];
—individual sterility, [18].
SPORES, reproduction of abnormal forms by, [11].
SPORTS, [11];
—in pigeons, [6].
SPOT pigeon, [5], [6].
SPRENGEL, C. K., on dichogamous plants, [15];
—on the hollyhock, [16];
—on the functions of flowers, [19].
SPROULE, Mr., transmission of hare-lip, [12].
SPURS, of fowls, [7];
—development of, in hens, [24].
SQUASHES, [10].
SQUINTING, hereditary, [12].
SQUIRRELS, generally sterile in captivity, [18].
SQUIRRELS, flying, breeding in confinement, [18].
“STAARHALSIGE Taube,” [5].
STAG, one-horned, supposed heredity of character in, [12];
—degeneracy of, in the Highlands, [20].
STAMENS, occurrence of rudimentary, [24];
—conversion of, into pistils, [10];
—into petals, [27].
Staphylea, [18].
STEENSTRUP, Prof., on the dog of the Danish Middens, [1];
—on the obliquity of flounders, [13].
STEINAN, J., on hereditary diseases, [12], [14].
STEPHENS, J. F., on the habits of the Bombycidæ, [8].
STERILITY, in dogs, consequent on close confinement, [1];
—comparative, of crosses, [16] (2);
—from changed conditions of life, [18];
—occurring in the descendants of wild animals bred in captivity, [18];
—individual, [18];
—resulting from propagation by buds, cuttings, bulbs, etc., [18];
—in hybrids, [19], [27], [28] (2);
—in specific hybrids of pigeons, [6];
—as connected with natural selection, [19].
STERNUM, characters of the, in rabbits, [4];
—in pigeons, [5] (2);
—in fowls, [7] (2);
—effects of disuse on the, [5] (2).
STEWART, H., on hereditary disease, [14].
STIGMA, variation of the, in cultivated Cucurbitaceæ, [10];
—satiation of the, [11] (2).
STOCKHOLM, fruit-trees of, [24].
STOCKS, bud-variation in, [11];
—effect of crossing upon the colour of the seed of, [11];
—true by seed, [12];
—crosses of, [15];
—varieties of, produced by selection, [20];
—reversion by the upper seeds in the pods of, [26].
STOCKTON, HOUGH, direct action of pollen, [11].
STOKES, Prof., calculation of the chance of transmission of abnormal peculiarities in man, [12].
STOLONS, variations in the production of, by strawberries, [10].
STOMACH, structure of the, affected by food, [24].
STONE in the bladder, hereditary, [12], [14].
STONEHENGE, on maturity of the dog, [1];
—inherited effects of injury, [12];
—cross between bulldog and greyhound, [15];
—close interbreeding of greyhound, [17];
—fleetness of racehorses, [21].
STORER, J., pedigree of cattle, [17].
STRAWBERRIES, [10];
—remarkable varieties of, [10] (2);
—hautbois diœcious, [10];
—selection in, [20];
—probable further modification of, [6];
—variegated, effects of soil on, [23].
STRICKLAND, A., on the domestication of Anser ferus, [8];
—on the colour of the bill and legs in geese, [8].
Strictœnas, [6].
STRIPES on young of wild swine, [3];
—of domestic pigs of Turkey, Westphalia, and the Zambesi, [3];
—of feral swine of Jamaica and New Granada, [3];
—of fruit and flowers, [11], [13];
—in horses, [2];
—in the ass, [2] (2);
—production of, by crossing species of Equidæ, [13] (2).
Strix grallaria, [24].
Strix passerina, [18].
“STRUPP-TAUBE,” [5].
STRUTHERS, D., osteology of the feet in solid-hoofed pigs, [3];
—on polydactylism, [12] (2).
STURM, prepotency of transmission of characters in sheep and cattle, [14];
—absorption of the minority in crossed races, [15];
—correlation of twisted horns and curled wool in sheep, [25].
SUB-SPECIES, wild, of Columba livia and other pigeons, [6].
SUCCESSION, geological, of organisms, [Introduction].
SUCKERS, bud-variation by, [11].
SUGAR-CANE, sterility of, in various countries, [18];
—sporting of, [11];
—white, liability of, to disease, [21], [25].
SUICIDE, hereditary tendency to, [12], [14].
SULIVAN, Admiral, on the horses of the Falkland Islands, [2];
—wild pigs of the Falkland Islands, [3];
—feral cattle of the Falkland Islands, [3] (2);
—feral rabbits of the Falkland Islands, [4].
SULTAN fowl, [7] (2).
Sus indicus, [3] (2), [16].
Sus pliciceps (figured), [3].
Sus scrofa, [3] (2), [16].
Sus scrofa palustris, [3].
Sus sennariensis, [3].
Sus vittatus, [3].
SWALLOWS, a breed of pigeons, [2].
SWEET peas, [15];
—crosses of, [15];
—varieties of, coming true by seed, [12];
—acclimatisation of, in India, [8].
SWEET William, bud-variation in, [11].
SWINHOE, R., on Chinese pigeons, [5], [6];
—on striped Chinese horses, [2];
—on the japanned peacock, [8].
SWITZERLAND, ancient dogs of, [1];
—pigs of, in the Neolithic period, [3];
—goats of, [3].
SYCAMORE, pale-leaved variety of the, [25].
SYKES, Colonel, on a pariah dog with crooked legs, [1];
—on small Indian asses, [2];
—on Gallus sonneratii, [7];
—on the voice of the Indian Kulm cock, [7];
—fertility of the fowl in most climates, [18].
SYMMETRY, hereditary departures from, [12].
Symphytum, variegated, [11].
SYPHILIS, hereditary, [25].
SYRIA, asses of, [2].
Syringa persica, chinensis, and vulgaris, [18].
TACITUS, on the care taken by the Celts in breeding animals, [20].
Tagetes signata, dwarf variety of, [12].
TAHITI, varieties of cultivated plants in, [22].
TAIL, never curled in wild animals, [24];
—rudimentary in Chinese sheep, [24].
TAIL-FEATHERS, numbers of, in breeds of pigeons, [5] (2);
—peculiarities of, in cocks, [7];
—variability of, in fowls, [7];
—curled, in Anas boschas, and tame drakes, [8].
TAIT, LAWSON, presence of hairs and teeth in ovarian tumours, [27].
TALENT, hereditary, [12].
TANKERVILLE, Earl of, on Chillingham cattle, [3], [17].
TANNER, Prof., effects of disuse of parts in cattle, [24].
TAPIR, sterility of the, in captivity, [18].
TARGIONI-TOZZETTI, on cultivated plants, [9];
—on the vine, [10];
—varieties of the peach, [10];
—origin and varieties of the plum, [10];
—origin of the cherry, [10];
—origin of roses, [10].
TARSUS, variability of the, in fowls, [7];
—reproduction of the, in a thrush, [27].
TARTARS, their preference for spiral-horned sheep, [20].
TAVERNIER, abundance of pigeons in Persia, [6].
Taxus baccata, [12].
TAYLOR, Mr., potato-grafting, [11].
TEEBAY, Mr., reversion in fowls, [13].
TEETH, number and position of, in dogs, [1];
—deficiency of, in naked Turkish dogs, [1];
—period of appearance of, in breeds of dogs, [1];
—precocity of, in highly-bred animals, [25];
—correlation of, with hair, [25];
—double row of, with redundant hair, in Julia Pastrana, [25];
—affected in form by hereditary syphilis and by pulmonary tubercle, [25];
—developed on the palate, [27].
TEGETMEIER, Mr., on a cat with monstrous teeth, [1];
—on a swift-like pigeon, [5];
—on sexual colours, [5];
—naked young of some pigeons, [5];
—fertility of hybrid pigeons, [6];
—on white pigeons, [21];
—reversion in crossed breeds of fowls, [7];
—chicks of the white silk fowl, [7];
—development of the cranial protuberance in Polish fowls, [7];
—on the skull in the Polish fowl, [7] (2);
—on the intelligence of Polish fowls, [7];
—correlation of the cranial protuberance and crest in Polish fowls, [7];
—development of the web in the feet of Polish fowls, [7];
—early development of several peculiarities in Spanish cocks, [7];
—on the comb in Spanish fowls, [7];
—on the Spanish fowl, [24];
—varieties of game-fowls, [7];
—pedigrees of game-fowls, [12];
—assumption of female plumage by a game-cock, [7];
—natural selection in the game-cock, [21];
—pugnacity of game-hens, [7];
—length of the middle toe in Cochin fowls, [7];
—origin of the Sebright bantam, [13];
—differences in the size of fowls, [7];
—effect of crossing in fowls, [7];
—effects of interbreeding in fowls, [17] (2);
—incubation by mongrels of non-sitting races of fowls, [13];
—inverse correlation of crest and comb in fowls, [7];
—occurrence of pencilled feathers in fowls, [13];
—on a variety of the goose from Sebastopol, [8];
—on the fertility of the peahen, [16];
—on the intercrossing of bees, [17].
TEMMINCK, origin of domestic cats, [1];
—origin of domestic pigeons, [6];
—on Columba guinea, [6];
—on Columba leucocephala, [6];
—asserted reluctance of some breeds of pigeons to cross, [6];
—sterility of hybrid turtle-doves, [6];
—variations of Gallus bankiva, [7];
—on a buff-coloured breed of turkeys, [8];
—number of eggs laid by the peahen, [16];
—breeding of guans in captivity, [18];
—behaviour of grouse in captivity, [18];
—sterility of the partridge in captivity, [18].
TENDRILS in Cucurbitaceæ, [10], [24].
TENNENT, Sir J. E., on the goose, [8];
—on the growth of the apple in Ceylon, [23];
—on the Jaffna sheep, [24].
Teredo, fertilisation in, [27].
TERRIERS, wry-legged, [21];
—white, subject to distemper, [25].
TESCHEMACHER, on a husked form of maize, [9].
TESSIER, on the period of gestation of the dog, [1];
—of the pig, [3];
—in cattle, [3];
—experiments on change of soil, [18].
Tetrao, breeding of species of, in captivity, [18].
Tetrapteryx paradisea, [18].
Teucrium campanulatum, pelorism in, [26].
TEXAS, feral cattle in, [3].
THEOGNIS, his notice of the domestic fowl, [7].
THEOPHRASTUS, his notice of the peach, [24].
Thesium, [23].
THOMPSON, Mr., on the peach and nectarine, [10];
—on the varieties of the apricot, [10];
—classification of varieties of cherries, [10];
—on the “Sister ribston-pippin,” [10];
—on the varieties of the gooseberry, [10] (2).
THOMPSON, WILLIAM, on the pigeons of Islay, [6];
—feral pigeons in Scotland, [6];
—colour of the bill and legs in geese, [8];
—breeding of Tetrao scotius in captivity, [18];
—destruction of black fowls by the osprey, [21].
THORN, grafting of early and late, [10];
—Glastonbury, [10].
THORNS, reconversion of, into branches, in pear trees, [24].
THRUSH, asserted reproduction of the tarsus in a, [27].
Thuja pendula or filiformis, a variety of T. orientalis, [10].
THURET, on the division of the zoospores of an alga, [27].
THWAITES, G. H., on the cats of Ceylon, [1];
—on a twin seed of Fuchsia coccinea and fulgens, [11].
TIBURTIUS, experiments in rearing wild ducks, [8].
TIGER, rarely fertile in captivity, [18].
Tigridia conchiflora, bud-variation in, [11].
TIME, importance of, in the production of races, [21].
TINZMANN, self-impotence in the potato, [17].
TISSUES, affinity of, for special organic substances, [27].
TITMICE, destructive to thin-shelled walnuts, [10];
—attacking nuts, [10];
—attacking peas, [21].
TOBACCO, crossing of varieties of, [16];
—cultivation of, in Sweden, [24].
TOBOLSK, red-coloured cats of, [1].
TOES, relative length of, in fowls, [7];
—development of fifth, in dogs, [24].
TOLLET, Mr., his selection of cattle, [20].
TOMATO, [15].
TOMES, inheritance of dental malformations, [12].
TOMTITS. See TITMICE.
TONGUE, relation of, to the beak in pigeons, [3].
TOOTH, occurrence of a molar, in place of an incisor, [27].
“TORFSCHWEIN,” [3].
TRAIL, R., on the union of half-tubers of different kinds of potatoes, [11].
TREES, varieties of, suddenly produced, [10];
—weeping or pendulous, [10];
—fastigiate or pyramidal, [10];
—with variegated or changed foliage, [10];
—early or late in leaf, [10];
—forest, non-application of selection to, [21].
“TREMBLEUR” (pigeons), [5].
TREMBLEY, on reproduction in Hydra, [27].
“TREVOLTINI” silkworms, [8] (2).
Trichosanthes anguina, [10].
TRICKS, inheritance of, [12] (2).
Trifolium minus and repens, [18].
TRIMORPHIC plants, conditions of reproduction in, [19].
TRISTRAM, H. B., selection of the dromedary, [20].
Triticum dicoccum, [9].
Triticum monococcum, [9].
Triticum spelta, [9].
Triticum turgidum, [9].
Triticum vulgare, wild in Asia, [9].
TRITON, breeding in the branchiferous stage, [27].
“TROMMEL-TAUBE,” [5].
“TRONFO” pigeon, [5].
Tropæolum, [13].
Tropæolum minus and majus, reversion in hybrids of, [22].
TROUBETZKOY, Prince, experiments with pear-trees at Moscow, [24].
TROUSSEAU, Prof., pathological resemblance of twins, [22].
TRUMPETER pigeon, [5];
—known in 1735, [6].
TSCHARNER, H. A. DE, graft-hybrid produced by inosculation in the vine, [11].
TSCHUDI, on the naked Peruvian dog, [1];
—extinct varieties of maize from Peruvian tombs, [9], [11].
TUBERS, bud-variation by, [11].
TUCKERMAN, Mr., sterility of Carex rigida, [18].
TUFTED ducks, [8].
TULIPS, variability of, [10];
—bud-variation in, [11] (2);
—influence of soil in “breaking,” [11].
TUMBLER pigeon, [5];
—short-faced, figured, [5];
—skull figured, [5];
—lower jaw figured, [5];
—scapula and furculum figured, [5];
—early known in India, [6];
—history of, [6];
—sub-breeds of, [6];
—young, unable to break the egg-shell, [21];
—probable further modification of, [21].
“TÜMMLER” (pigeons), [5].
TUMOURS, ovarian, occurrence of hairs and teeth in, [27];
—polypoid, origin of, [27].
TURBIT (pigeon), [5], [6].
TURKEY, domestic, origin of, [8];
—crossing of, with North American wild turkey, [8] (2);
—breeds of, [8];
—crested white cock, [8];
—wild, characters of, [8] (2);
—degeneration of, in India, [8], [23];
—failure of eggs of, in Delhi, [18];
—feral, on the Parana, [6];
—change produced in, by domestication, [22].
TURKEY, striped young pigs in, [3].
“TURKISCHE TAUBE,” [5].
TURNER (pigeon), [5].
TURNER, C., on the hollyhock, [3].
TURNER, W., on cells, [27].
TURNIPS, origin of, [9];
—reversion in, [13];
—run wild, [13];
—crosses of, [15] (2);
—Swedish, preferred by hares, [21];
—acclimatisation of, in India, [24].
TURNSPIT, on an Egyptian monument, [1];
—crosses of the, [15].
TURTLE-DOVE, white and coloured, crossing of, [15].
Turtur auritus, hybrids of, with T. cambayensis and T. suratensis, [6].
Turtur risorius, crossing of, with the common pigeon, [6];
—hybrids of with T. vulgaris, [6].
Turtur suratensis, sterile hybrids of, with T. vulgaris, [6];
—hybrids of, with T. auritus, [6].
Turtur vulgaris, crossing of, with the common pigeon, [6];
—hybrid of, with T. risorius, [6];
—sterile hybrids of, with T. suratensis and Ectopistes migratorius, [6].
TUSKS of wild and domesticated pigs, [3] (2).
Tussilago farfara, variegated, [11].
TWIN-SEED of Fuchsia coccinea and fulgens, [11].
TYERMAN, B., on the pigs of the Pacific Islands, [3], [15];
—on the dogs of the Pacific Islands, [15].
TYLOR, Mr., on the prohibition of consanguineous marriages, [17].
UDDERS, development of the, [24].
Ulex, double-flowered, [18].
Ulmus campestris and effusa, hybrids of, [17].
UNIFORMITY of character, maintained by crossing, [15].
UNITS of the body, functional independence of the, [27].
UNITY or plurality of origin of organisms, [Introduction].
UREA, secretion of, [27].
USE and disuse of parts, effects of, [24] (2), [26] (2), [28] (2);
—in rabbits, [4];
—in ducks, [8].
UTILITY, considerations of, leading to uniformity, [21].
VALENTIN, experimental production of double monsters by, [27].
Vallota, [17].
VAN BECK, BARBARA, a hairy-faced woman, [12].
VAN MONS, on wild fruit-trees, [9], [22];
—production of varieties of the vine, [10];
—correlated variability in fruit-trees, [25];
—production of almond-like fruit by peach-seedlings, [10].
Vanessa, species of, not copulating in captivity, [18].
VARIABILITY, [Introduction], [27] (2), [28];
—causes of, [22];
—correlated, [25], [26] (2), [28] (2);
—law of, equable, [26] (2);
—necessity of, for selection, [19];
—of selected characters, [21];
—of multiple homologous parts, [26].
VARIATION, laws of, [24];
—continuity of, [21];
—possible limitation of, [21], [28] (2);
—in domestic cats, [1];
—origin of breeds of cattle by, [3];
—in osteological characters of rabbits, [4];
—of important organs, [10];
—analogous or parallel, [9];
—in horses, [2];
—in the horse and ass, [2];
—in fowls, [7];
—in geese, [8];
—exemplified in the production of fleshy stems in cabbages, etc., [9];
—in the peach, nectarine, and apricot, [10] (2);
—individual, in wheat, [9].
VARIEGATION of foliage, [11], [18].
VARIETIES and species, resemblance of, [Introduction], [28];
—conversion of, into species, [Introduction];
—abnormal, [28];
—domestic, gradually produced, [28].
VARRO, on domestic ducks, [8];
—on feral fowls, [13];
—crossing of the wild and domestic ass, [20].
VASEY, Mr., on the number of sacral vertebræ in ordinary and humped cattle, [3];
—on Hungarian cattle, [3].
VAUCHER, sterility of Ranunculus ficaria and Acorus calamus, [18].
VEGETABLES, cultivated, reversion in, [13];
—European, culture of, in India, [18] (2).
VEITH, Mr., on breeds of horses, [2].
Verbascum, intercrossing of species of, [10], [15], [16];
—reversion in hybrids of, [11];
—self-sterility of, [17];
—contabescent, wild plants of, [18];
—villosity in, [23].
Verbascum austriacum, [17].
Verbascum blattaria, [16] (2).
Verbascum lychnitis, [16] (2), [17].
Verbascum nigrum, [17].
Verbascum phœniceum, [16], [17];
—variable duration of, [24].
Verbascum thapsus, [16], [17].
VERBENAS, origin of, [10];
—white, liability of, to mildew, [21] (2);
—scorching of dark, [21] (2);
—effect of changed conditions of life on, [23].
VERLOT, on the dark-leaved barberry, [10];
—inheritance of peculiarities of foliage in trees, [10];
—production of Rosa cannabifolia by bud-variation from R. alba, [11];
—bud-variation in Aralia trifoliata, [11];
—variegation of leaves, [11];
—colours of tulips, [11];
—uncertainty of inheritance, [12];
—persistency of white flowers, [12];
—peloric flowers of Linaria, [13];
—tendency of striped flowers to uniformity of colour, [14];
—non-intercrossing of certain allied plants, [15];
—sterility of Primulæ with coloured calyces, [18];
—on fertile proliferous flowers, [18];
—on the Irish yew, [21];
—differences in the Camellia, [22];
—effect of soil on the variegated strawberry, [23];
—correlated variability in plants, [25].
Verruca, [13], [27].
VERTEBRAE, characters of, in rabbits, [4];
—in ducks, [8] (2);
—number and variations of, in pigeons, [5] (2);
—number and characters of, in fowls, [7];
—variability of number of, in the pig, [3].
VERTUCH. See PUTSCHE.
“VERUGAS,” [23].
VESPUCIUS, early cultivation in Brazil, [9].
VIBERT’S experiments on the cultivation of the vine from seed, [10].
Viburnum opulus, [19], [24].
Vicia sativa, leaflet converted into a tendril in, [27].
VICUNAS, selection of, [20].
VILLOSITY of plants, influenced by dryness, [23].
VILMORIN, cultivation of the wild carrot, [9], [23];
—colours of tulips, [11];
—uncertainty of inheritance in balsams and roses, [12];
—experiments with dwarf varieties of Saponaria calabrica and Tagetes signata, [12];
—reversion of flowers by stripes and blotches, [13];
—on variability, [22].
Vinca minor, sterility in, [18].
VINE, [10];
—parsley-leaved, reversion of, [11];
—graft-hybrid produced by inosculation in the, [11];
—disease of, influenced by colour of grapes, [21] (2);
—influence of climate, etc., on varieties of the, [23];
—diminished extent of cultivation of the, [24];
—acclimatisation of the, in the West Indies, [24].
Viola, species of, [10].
Viola lutea, different coloured flowers in, [11].
Viola tricolor, reversion in, [13] (2).
VIRCHOW, Prof., on the growth of bones, [24], [27];
—on cellular prolification, [16];
—independence of the elements of the body, [27];
—on the cell-theory, [27];
—presence of hairs and teeth in ovarian tumours, [27];
—of hairs in the brain, [27];
—special affinities of the tissues, [27];
—origin of polypoid excrescences and tumours, [27].
VIRGIL, on the selection of seed corn, [9], [20];
—of cattle and sheep, [20].
VIRGINIAN Islands, ponies of, [2].
VISION, hereditary peculiarities of, [12] (2);
—in amphibious animals, [20];
—varieties of, [24];
—affections of organs of, correlated with other peculiarities, [25].
Vitis vinifera, [10], [11].
Viverra, sterility of species of, in captivity, [18].
VOGEL, varieties of the date palm, [22].
VOGT, on the indications of stripes on black kittens, [13].
VOICE, differences of, in fowls, [7];
—peculiarities of, in ducks, [8];
—inheritance of peculiarities of, [12].
VOLZ, on the history of the dog, [1];
—ancient history of the fowl, [7];
—domestic ducks unknown to Aristotle, [8];
—Indian cattle sent to Macedonia by Alexander, [20];
—mention of mules in the Bible, [20];
—history of the increase of breeds, [21].
VON BERG, on Verbascum phœniceum, [24].
VOORHELM, G., his knowledge of hyacinths, [10], [22].
VROLIK, Prof., on polydactylism, [12];
—influence of the shape of the mother’s pelvis on her child’s head, [26].
WADE, drooping eyelids transmitted, [12].
WADERS, behaviour of, in confinement, [18].
WAGNER, MORITZ, oriental dogs, [21].
WAHLENBORG, on the propagation of Alpine plants by buds, runners, bulbs, etc., [18].
“WAHLVERWANDTSCHAFT” of Gärtner, [19].
WALES, white cattle of, in the tenth century, [3].
WALKER, A., on intermarriage, [11];
—on the inheritance of polydactylism, [12].
WALKER, D., advantage of change of soil to wheat, [18].
WALKER, R., reversion in cattle, [13].
WALLACE, A. R., on the multiple origin of the dog, [1];
—on a striped Javanese horse, [2];
—on the conditions of life of feral animals, [13];
—artificial alteration of the plumage of birds, [23];
—on polymorphic butterflies, [27];
—on reversion, [28];
—on the limits of change, [28].
WALLACE, Dr., on the sterility of Sphingidae hatched in autumn, [18].
WALLACHIAN sheep, sexual peculiarities in the horns of, [3].
WALLFLOWER, bud-variation in, [11].
WALLICH, Dr., on Thuja pendula or filiformis, [10].
WALNUTS, [10] (2);
—thin-shelled, attacked by tomtits, [10];
—grafting of, [22].
WALSH, B. D., on attacks of insects, [10];
—on galls, [23] (2);
—his “Law of equable variability,” [26] (2).
WALTHER, F. L., on the history of the dog, [1];
—on the intercrossing of the zebu and ordinary cattle, [3].
WARING, Mr., on individual sterility, [18].
WATERER, Mr., spontaneous production of Cytisus alpino-laburnum, [11].
WATERHOUSE, G. R., on the winter-colouring of Lepus variabilis, [4].
WATERTON, C., production of tailless foals, [2];
—on taming wild ducks, [8];
—on the wildness of half-bred wild ducks, [13];
—assumption of male characters by a hen, [13].
WATSON, H. C., on British wild fruit-trees, [9];
—on the non-variation of weeds, [9];
—origin of the plum, [10];
—variation in Pyrus malus, [10];
—on Viola amœna and tricolor, [10];
—on reversion in Scotch kail, [13];
—fertility of Draba sylvestris when cultivated, [18];
—on generally distributed British plants, [23].
WATTLES, rudimentary, in some fowls, [24].
WATTS, Miss, on Sultan fowls, [7].
WEBB, JONAS, interbreeding of sheep, [17].
WEBER, effect of the shape of the mother’s pelvis on her child’s head, [26].
WEDDERBURN, Mr., correlation of teeth and hair, [25].
WEEDS, supposed necessity for their modification, coincidently with cultivated plants, [9].
WEEPING varieties of trees, [10].
WEEPING habit of trees, capricious inheritance of, [12] (2).
WEEVIL, injury done to stone-fruit by, in North America, [21].
WEIJENBERGH, on parthenogenesis, [27].
WEIR, H., large litter of pigs, [16].
WEIR, JENNER, on the japanned peacock, [8];
—mare and quagga, [11];
—wildness of mule siskins, [13].
WEISMANN, Prof., reversion from unnatural conditions, [13];
—isolation, [23];
—dimorphic butterflies, [23];
—causes of variability, [23].
WELSH cattle, descended from Bos longifrons, [3].
WEST Indies, feral pigs of, [3];
—effect of climate of, upon sheep, [3].
WESTERN, Lord, change effected by, in pigs, [3] (2);
—in the sheep, [20].
WESTPHALIA, striped young pigs in, [3].
WESTWOOD, J. O., on peloric flowers of Calceolaria, [26].
WETHERELL, Mr., on inheritance of mutilations, [12].
WHATELY, Archbishop, on grafting early and late thorns, [10].
WHEAT, specific unity or diversity of, [9] (4);
—Hasora, [9];
—presence or absence of barbs in, [9];
—Godron on variations in, [9];
—varieties of, [9] (2);
—effects of soil and climate on, [9];
—deterioration of, [9];
—crossing of varieties of, [9], [15], [16], [17];
—in the Swiss lake-dwellings, [9];
—selection applied to, [9], [20];
—increased fertility of hybrids of, with Ægilops, [16];
—advantage of change of soil to, [18];
—differences of, in various parts of India, [18];
—continuous variation in, [20];
—red, hardiness of, [21], [25];
—Fenton, [21];
—natural selection in, [21];
—varieties of, found wild, [22];
—effects of change of climate on, [24];
—ancient variety of, [28].
WHITBY, Mrs., on the markings of silkworms, [8];
—on the silk-moth, [8].
WHITE, Mr., reproduction of supernumerary digits after amputation, [12];
—time occupied in the blending of crossed races, [15].
WHITE, GILBERT, vegetable diet of dogs, [24].
WHITE and white-spotted animals, liability of, to disease, [25] (2).
WHITE flowers, most truly reproduced by seed, [12].
WICHURA, MAX, on hybrid willows, [13];
—analogy between the pollen of old-cultivated plants and of hybrids, [22].
WICKING, Mr., inheritance of the primary characters of Columba livia in cross-bred pigeons, [6];
—production of a white head in almond tumblers, [20].
WICKSTED, Mr., on cases of individual sterility, [18].
WIEGMANN, spontaneous crossing of blue and white peas, [11];
—crossing of varieties of cabbage, [17];
—on contabescence, [18].
WIGHT, Dr., sexual sterility of plants propagated by buds, etc., [18].
WILCKENS, Dr., effect of previous impregnation, [11];
—alpine breeds, [24];
—drooping ears, [24];
—correlation of hair and horns, [25].
WILDE, Sir W. R., occurrence of Bos frontosus and longifrons in Irish crannoges, [3];
—attention paid to breeds of animals by the ancient Irish, [20].
WILDER, Dr. B., on the brain of dogs, [1];
—supernumerary digits, [12].
WILDMAN, on the dahlia, [20], [23].
WILDNESS of the progeny of crossed tame animals, [13] (2).
WILKES, Capt., on the taming of pigeons among the Polynesians, [18].
WILKINSON, J., on crossed cattle, [16].
WILLIAMS, Mr., change of plumage in a Hamburgh hen, [7].
WILLIAMS, Mr., intercrossing of strawberries, [10].
WILLIAMSON, Capt., degeneration of dogs in India, [1];
—on small Indian asses, [2].
WILLIAMSON, Rev. W., doubling of Anemone coronaria by selection, [20].
WILLOWS, weeping, [10];
—reversion of spiral-leaved weeping, [11];
—hybrids of, [22];
—galls of, [23] (2).
WILLUGHBY, F., notice of spot pigeons, [5];
—on a fantail pigeon, [6];
—on tumbler pigeons, [6];
—on the turbit, [6];
—on the barb and carrier pigeons, [6];
—on the hook-billed duck, [8].
WILMOT, Mr., on a crested white Turkey-cock, [8];
—reversion of sheep in colour, [13].
WILSON, B. O., fertility of hybrids of humped and ordinary cattle in Tasmania, [3].
WILSON, Dr., prepotency of the Manx over the common cat, [14].
WILSON, JAMES, origin of dogs, [1].
WILSON, Mr., on prepotency of transmission in sheep, [14];
—on the breeding of bulls, [20].
WINGS, proportionate length of, in different breeds of pigeons, [5] (2);
—of fowls, effects of disuse on, [7];
—characters and variations of, in ducks, [8];
—diminution of, in birds of small islands, [8] (2).
WING-FEATHERS, number of, in pigeons, [5];
—variability of, in fowls, [7].
WOLF, recent existence of, in Ireland, [1];
—barking of young, [1];
—hybrids of, with the dog, [1].
WOLF-DOG, black, of Florida, [1].
WOLVES, North American, their resemblance to dogs of the same region, [1] (2);
—burrowing of, [1].
WOODBURY, Mr., crossing of the Ligurian and common hive bees, [8], [17];
—variability of bees, [8].
WOODWARD, S. P., on Arctic Mollusca, [22].
WOOD, WILLOUGHBY, reversion from a cross, [13];
—on Mr. Bates’ cattle, [17].
WOOLER, W. A., on the young of the Himalayan rabbit, [4];
—persistency of the coloured calyx in a crossed polyanthus, [10].
WOUNDS, healing of, [24].
WRIGHT, J., production of crippled calves by short-horned cattle, [17];
—on selection in cattle, [20];
—effect of close interbreeding on pigs, [17];
—deterioration of game-cocks by close interbreeding, [17].
WRIGHT, STRETHILL, on the development of the hydroida, [27].
WYMAN, Dr., on Niata cattle, and on a similar malformation in the codfish, [3];
—on Virginian pigs, [21];
—browsing under water, [24].
XENOPHON, on the colours of hunting dogs, [20].
XIMENES, Cardinal, regulations for the selection of rams, [20].
“YAHU,” the name of the pigeon in Persia, [5].
YAKS, domestication of, [20];
—selection of white-tailed, [20].
YAM, development of axillary bulbs in the, [18].
YARRELL, Mr., deficiency of teeth in hairless dogs, [1], [25];
—on ducks, [8], [22];
—characters of domestic goose, resembling those of Anser albifrons, [8];
—whiteness of ganders, [8];
—variations in gold-fish, [8] (2);
—assumption of male plumage by the hen-pheasant, [13];
—effect of castration upon the cock, [13] (2);
—breeding of the skylark in captivity, [18];
—plumage of the male linnet in confinement, [18];
—on the dingo, [22].
YELLOW fever, in Mexico, [23].
YEW, fastigiate, [21].
YEW, Irish, hardy in New York, [24].
YEW, weeping, [10];
—propagation of, by seed, [12].
YOLK, variations of, in the eggs of ducks, [8].
YOUATT, Mr., history of the dog, [1];
—variations of the pulse in breeds of dogs, [1];
—liability to disease in dogs, [1], [21];
—inheritance of goitre in dogs, [12];
—on the greyhound, [1] (2);
—on King Charles’ spaniels, [1];
—on the setter, [1];
—on breeds of horses, [2];
—variation in the number of ribs in the horse, [2];
—inheritance of diseases in the horse, [12] (2);
—introduction of Eastern blood into English horses, [20] (2);
—on white Welsh cattle, [3], [20];
—improvement of British breeds of cattle, [3];
—rudiments of horns in young hornless cattle, [13], [24];
—on crossed cattle, [16], [17];
—on Bakewell’s long-horned cattle, [17];
—selection of qualities in cattle, [20];
—degeneration of cattle by neglect, [21];
—on the skull in hornless cattle, [25];
—disease of white parts of cattle, [25];
—displacement of long-horned by short-horned cattle, [28];
—on Angola sheep, [3];
—on the fleece of sheep, [3];
—correlation of horns and fleece in sheep, [3];
—adaptation of breeds of sheep to climate and pasture, [3];
—horns of Wallachian sheep, [3];
—exotic sheep in the Zoological Gardens, [3], [24];
—occurrence of horns in hornless breeds of sheep, [13];
—on the colour of sheep, [13];
—on interbreeding sheep, [17];
—on Merino rams in Germany, [20];
—effect of unconscious selection on sheep, [20];
—reversion of Leicester sheep on the Lammermuir Hills, [21];
—on many-horned sheep, [25];
—reduction of bone in sheep, [21];
—persistency of character in breeds of animals in mountainous countries, [14];
—on interbreeding, [17];
—on the power of selection, [20] (2);
—slowness of production of breeds, [21];
—passages in the Bible relating to the breeding of animals, [20].
YOUNG, J., on the Belgian rabbit, [4].
YULE, Capt., on a Burmese hairy family, [14], [25].
ZAMBESI, striped young pigs on the, [3].
ZAMBOS, character of the, [13].
ZARCO, J. G., introduction of rabbits into Porto Santo by, [4].
Zea altissima, [9];
—mays, [9].
ZEBU, [3];
—domestication of the, [3];
—fertile crossing of, with European cattle, [3], [16].
ZEBRA, hybrids of, with the ass and mare, [13].
Zephyranthes candida, [18].
Zinnia, cultivation of, [22].
ZOLLINGER on Malayan penguin ducks, [8].
ZOOSPORE, division of, in Algæ, [23].
“ZOPF-TAUBE,” [5].