Mr. Christian, in his essay, supports the view, that the offspring bears the greatest resemblance to that parent whether male or female, which has exerted the greatest sway of generative influence in the formation of the fœtus, "that any hypothesis which would assign a superiority, or set limits to the influence of either sex in the product of generation is unsound and inadmissible," and he thus concludes—"as therefore it is unsafe to trust to the qualities of any individual animal, male or female, in improving stock, the best bred and most perfect animals of both sexes should be selected and employed in propagation; there being, in short, no other certain or equally efficacious means of establishing or preserving an eligible breed."
Mr. Dallas, in his essay, starts with the idea that the seminal fluid of the male invests the ovum, the formation of which he ascribes to the female; and he supports the opinion, that where external appearance is concerned, the influence of the male will be discovered; but in what relates to internal qualities, the offspring will take most from the female. He concludes thus:—"When color, quality of fleece, or outward form is wanted, the male may be most depended on for these; but when milk is the object, when disposition, hardiness, and freedom from diseases of the viscera, and, in short, all internal qualities that may be desired, then the female may be most relied on."
One of the most valuable of these papers was written by the Rev. Henry Berry of Worcestershire, in which, after stating that the question proposed is one full of difficulty and that the discovery of an independent quality such as that alluded to, in either sex, would be attended with beneficial results, he proceeds to show, that it is not to sex, but to high blood, or in other words, to animals long and successfully selected, and bred with a view to particular qualifications, whether in the male or female parent, that the quality is to be ascribed, which the Highland Society has been desirous to assign correctly.
The origin of the prevalent opinion which assigns this power principally to the male, he explains by giving the probable history of the first efforts in improving stock. The greatest attention would naturally be paid to the male, both on account of his more extended services, and the more numerous produce of which he could become the parent; in consequence of which sires would be well-bred before dams. "The ideas entertained respecting the useful qualities of an animal would be very similar and lead to the adoption of a general standard of excellence, towards which it would be required that each male should approximate; and thus there would exist among what may be termed fashionable sires, a corresponding form and character different from, and superior to, those of the general stock of the country. This form and character would in most instances have been acquired by perseverance in breeding from animals which possessed the important or fancied requisites, and might therefore be said to be almost confirmed in such individuals. Under these circumstances, striking results would doubtless follow the introduction of these sires to a common stock; results which would lead superficial observers to remark, that individual sires possessed properties as males, which in fact were only assignable to them as improved animals."
The opinion entertained by some, that the female possesses the power generally ascribed to the male, he explains also by a reference to the history of breeding: "It is well known to persons conversant with the subject of improved breeding, that of late years numerous sales have taken place of the entire stocks of celebrated breeders of sires, and thus, the females, valuable for such a purpose, have passed into a great number of hands. Such persons have sometimes introduced a cow so acquired to a bull inferior in point of descent and general good qualities, and the offspring is known, in many instances, to have proved superior to the sire by virtue of the dam's excellence, and to have caused a suspicion in the minds of persons not habituated to compare causes with effects, that certain females also possess the property in question."
The writer gives various instances illustrative of his views, in some of which the male only, and in others the female only, was the high-bred animal, in all of which the progeny bore a remarkable resemblance to the well-bred parent. He says, that where both parents are equally well bred, and of nearly equal individual excellence, it is not probable that their progeny will give general proof of a preponderating power in either parent to impress peculiar characteristics upon the offspring;—yet in view of all the information we have upon the subject, he recommends a resort to the best males as the most simple and efficacious mode of improving such stocks as require improvement, and the only proceeding by which stock already good can be preserved in excellence.
Mon. Giron[17] expresses the opinion that the relative age and vigor of the parents exercises very considerable influence, and states as the results of his observation, that the offspring of an old male and a young female resembles the father less than the mother in proportion as the mother is more vigorous and the father more decrepit, and that the reverse occurs with the offspring of an old female and a young male.
Among the more recent theories or hypotheses which have been started regarding the relative influence of the male and female parents, those of Mr. Orton, presented in a paper read before the Farmers' Club at Newcastle upon Tyne, on the Physiology of Breeding, and of Mr. Walker in his work on Intermarriage, as they both arrived to a certain extent, at substantially the same conclusions by independent observations of their own and as these seem to agree most nearly with the majority of observed facts, are deemed worthy of favorable mention.
The conclusions of Mr. Orton, briefly stated,[18] are, that in the progeny there is no casual or haphazard blending of the parts or qualities of the two parents, but rather that organization is transmitted by halves, or that each parent contributes to the formation of certain structures, and to the development of certain qualities. Advancing a step further, he maintains, that the male parent chiefly determines the external characters, the general appearance, in fact, the outward structure and locomotive powers of the offspring, as the framework, or bones and muscles, more particularly those of the limbs, the organs of sense and skin; while the female parent chiefly determines the internal structures and the general quality, mainly furnishing the vital organs, i.e., the heart, lungs, glands and digestive organs, and giving tone and character to the vital functions of secretion, nutrition and growth. "Not however that the male is without influence on the internal organs and vital functions, or the female without influence on the external organs and locomotive powers of their offspring. The law holds only within certain restrictions, and these form as it were a secondary law, one of limitations, and scarcely less important to be understood than the fundamental law itself."
Mr. Orton relies chiefly on the evidence presented by hybrids, the progeny of distinct species, or by crosses between the most distinct varieties embraced within a single species, to establish his law. The examples adduced are chiefly from the former. The mule is the progeny of the male ass and the mare; the hinny that of the horse and the she ass. Both hybrids are the produce of the same set of animals. They differ widely, however, in their respective characters—the mule in all that relates to its external characters having the distinctive features of the ass,—the hinny, in the same respects having all the distinctive features of the horse; while in all that relates to the internal organs and vital qualities, the mule partakes of the character of the horse, and the hinny of those of the ass. Mr. Orton says—"The mule, the produce of the male ass and mare, is essentially a modified ass: the ears are those of an ass somewhat shortened; the mane is that of the ass, erect; the tail is that of an ass; the skin and color are those of an ass somewhat modified; the legs are slender and the hoofs high, narrow and contracted, like those of an ass. In fact, in all these respects it is an ass somewhat modified. The body and barrel, however, of the mule are round and full, in which it differs from the ass and resembles the mare.