Diversions of a Naturalist

by Sir E. Ray Lankester

These and similar stories are related to-day, and such stories have been related from time immemorial. But they are always "hear-say." The witnesses and the facts are never carefully examined, and the degree of closeness of the agreement between the mark and its supposed cause are never really demonstrated. Nor has anyone undertaken a statistical examination with the view of showing that the vague agreement of the mark with the arresting object seen by the mother is anything more than an accidental coincidence, nor (in regard to many such stories) has it been proved that the mother really did see or notice any such terrifying object as she afterwards declares (and possibly thinks) she did. Moreover, no one has carefully and scientifically made crucial experiments with animals, similar to that of the patriarch Jacob. The experiments and their record would not be difficult with animals. Though some farmers may believe that such influences do operate on their breeding dams, there is no known or recognized application of Jacob's method to the production of desired form or colour in domesticated animals. We are not concerned with "possibilities." What is needed is a series of demonstrative experiments, or critical cases. And these are, as yet, not forthcoming.

Telegony is the name given to the hypothesis that the offspring of a known sire sometimes inherit characters from a previous mate of their dam. The name means reproduction (Greek, gonos) influenced by a remote agent (Greek, tele = from afar). There is no question about "possibility" here. Such an "infection" of a dam by a previous mate is not improbable. According to Darwin "farmers in South Brazil are convinced that mares which have once borne mules, when subsequently put to horses, are extremely liable to produce colts striped like a mule." On the other hand, the Baron de Parana states that he has many relatives and friends who have large establishments for the rearing of mules where they obtain from 400 to 1000 mules in a year. In all these establishments, after two or three crossings of the mare and ass, the breeders cause the mare to be put to a horse; yet the pure-bred foals so produced have never in a single case resembled either an ass or a mule.

A celebrated case to which Darwin attached importance was that of Lord Morton's mare, reported to the Royal Society in 1820. This mare, after bearing a hybrid by a quagga (a striped equine related to the zebra) produced, to a black Arabian horse, three foals showing a number of stripes, and in one of them more stripes were present than in the quagga hybrid. This seems at first sight strong evidence in favour of "infection" of the mare by the early quagga mate. But it appears that stripes are frequently seen in high-caste Arab horses, and colts cross-bred from such and other breeds of horse sometimes present far more distinct bars across the legs and other zebra-like markings than were seen in the late offspring of Lord Morton's Arabian mare. The fact appears to be that all the living species of the horse family (horses, asses, quaggas, and zebras) are descended from an ancestry of "striped" equines, and are liable occasionally to "throw back" to their striped ancestry, more or less.

Professor Cossar Ewart determined some years ago to submit the matter to direct experiment, and has related his results in a book ("The Penicuik Experiments," 1899). The South African equine called the quagga, which was that used by Lord Morton, having become extinct, Professor Ewart made use of a richly striped Burchell's zebra. Thirty mares put to this animal produced seventeen hybrids, and subsequently these mares, put to horse-stallions, produced twenty pure-bred foals. All the zebra hybrids were richly and very distinctly striped. Of the twenty later pure-bred horse-foals from the same mares three only presented stripe-like markings at birth, and these were few and indistinct. They disappeared when the foal's coat was shed. Their mothers were Highland mares. But the value of the faint striping in these three instances as evidence in support of telegony is at once destroyed by the fact that Professor Ewart obtained at the same time pure-bred foals from similar Highland mares which had never seen a zebra. Two of these pure-bred Highland foals showed stripes at birth, and one acquired stripes later; and further, whilst the stripes on the foals born after hybrids had been produced by their mothers disappeared with the foal's coat, the stripes on the three pure-bred colts whose mothers had never been near a zebra persisted for a longer period. Similar experiments confirmed these results, showing that traces of striping are no more likely to occur on the offspring of a mare which has previously produced a mule with a zebra or an ass, than on one whose dam has neither seen nor been near to a zebra or an ass. Lord Morton's case thus falls to the ground.

Breeders of dogs are (or were) even more thoroughly convinced of the fact of telegony than breeders of horses. But Sir Everett Millais, who devoted thirty years to the breeding of dogs and experiments on this question, states that he has never seen a case of telegony. And recent experiments of the most definite kind support his conclusion. Dalmatians, deerhounds, and retrievers have been used in these experiments. Many such experiments in telegony are accidentally or unwittingly made every year with dogs. An undesired crossing of two breeds takes place, but when subsequent pure breeding takes place no "telegonic" infection of the mother is observed. Cases believed to be due to telegony have on examination proved to be due to the carelessness of stablemen, who have allowed a dog to escape temporarily from the kennels or to enter them uninvited. The men have attributed the mongrels so begotten to telegony in order to conceal their negligence.

Another curious case was that of a rickety spaniel puppy, which was exhibited a few years ago at the Zoological Society and believed by the exhibitor to owe its bandy legs to "telegonic" infection of the mother by a dachshund, with which she was supposed to have mated a year or more before being put to the father of the spaniel. Its true nature was at once recognized by the experts present, the bandy legs being those caused by "rickets," and not like those of the well-known dachshund breed.

It appears that the explanations widely prevalent of many apparently strange things discussed in the preceding chapters, such as live toads buried in rocks, the water-finder's mystic rod, the coincidence of birth-marks and maternal impressions, and the inheritance of offspring from a previous mate of their dam, are hasty and unverified suppositions, which have never been properly tested, and that when the wonder-provoking statements made and the actual facts in question are properly and sufficiently examined, according to the rules of evidence and common sense, it is discovered that the assumption of occult or exceptional causes in explanation of such strange things are not justified, but that these strange things owe their strangeness in large part to the incorrect and incomplete observation of those who report them, and to that love of marvel and mystery which, like hope, springs eternal in the human breast.

It is a remarkable proof of the reality of the belief in telegony—though not a proof of the reality of telegony—that amongst breeders of horses and dogs the selling value of a dam which has borne young to an inferior sire or to one of a distinct species, is largely diminished as compared with that of a dam which has been mated with a first-rate sire of her own breed. Darwin himself was led, by his inquiries into a similar occurrence in plants, to favour the notion that a sire could so "infect" a mare that her offspring by a later sire would in some instances show traces of the characters of the earlier sire. The parts of a plant which form the coverings of the fertilized ovule, the "coats" of the seed and the seed-case and fruit, are, of course, parts of the maternal plant. In each of the ovules which grow in the central part of a flower (the so-called "pistil") is an egg cell like that of an animal. This is "fertilized" by the pollen-grains which are brought by wind or by insects from the "stamens" of another flower. Each pollen-grain thus brought to the surface of the pistil elongates into a delicate filament, and penetrates into it, and so reaches an egg cell, with which it fuses. Then the surrounding tissues grow and swell up, forming the seed coats and the fruit. They are parts of the egg-cell-producing or "mother" flower. Thus the pulp and "rind" or skin of an orange is part of the mother plant, not of the germs or young embedded in the "pips." It is found that if an orange-flower is deliberately fertilized by placing on its pistil the pollen-grains of a lemon-flower, not only are the ovules of the orange fertilized, but the surrounding structures, which enlarge to form the fruit and are parts of the orange plant quite distinct from the ovules, also become affected by the pollen. In one well-observed case when an orange-flower was fertilized by a gardener with the pollen of a lemon-flower, the skin or rind of the resulting fruit was found to exhibit stripes of perfectly characterized lemon peel (having the colour and flavour of lemon peel), alternating with stripes of the proper orange peel.

The same thing has been observed in apples, melons, orchids, rhododendrons, grapes, maize, and peas, when one variety has been fertilized by the pollen of another, or when one species has been fertilized by the pollen of an allied but distinct species. The fruit in these cases (not simply the germ or young plant within it) has been found in some instances to have some of the colour, flavour, or shape and marking of the fertilizing variety or species blended or else mixed like a patchwork with that characteristic of the fertilized variety or species. The egg-producing or mother plant not merely has its ovules fertilized, but its tissues for some distance around are infected and made to take on—in parts of their living, growing substance—some of the quality of the fertilizing species. A similar thing occurs, though rarely, when cuttings of one plant are grafted on to another. The living tissue either of graft or of stock, and sometimes of both, is affected by the fusion with it of the tissue of the second plant united with it. And this appears to be a kind of "infection"—living particles passing from one to the other, and producing a mosaic or patchwork of the two kinds of living substance characteristic of each of the united plants.

If an individual flower were to produce in a second year after its first fertilization and seed production a second set of ovules which could be fertilized by a kind of pollen differing from the first, it would not be surprising did that second set of ovules sometimes show characteristics due to the infection of the maternal tissues by the pollen used in the first year. But flowers do not survive and produce ovules in a second year. They are completely used up each year, and drop off as "fruits" from the plant which bears them. With many animals, however, the facts are otherwise. The same mother produces from the ovary year after year successive ovules, and it would thus be quite intelligible that the fertilizing sperm of one year should frequently have so affected or infected the egg-producing organ or ovary as to result in the conveyance to the later crop of egg cells separated from the ovary, some of the qualities of the earlier male parent. These considerations warrant the guess or "hypothesis" of telegony in animals. But all such guesses must be put to the proof, and not accepted simply because there is no reason to conclude that they are impossible. As things at present stand, there is no evidence, resulting either from deliberate experiment or from exact observation and record of the natural breeding of animals, to justify us in holding, as an established fact, that the offspring of a given sire and dam is, even in rare cases, affected by the previous mating of the dam with another sire. Naturalists would be deeply interested in the production of even one indisputable instance of this occurrence.