The Principles of Breeding / or, Glimpses at the Physiological Laws involved in the Reproduction and Improvement of Domestic Animals

by S. L. Goodale

Dr. Carpenter, in the last edition of his work on physiology, says it is by no means an infrequent occurrence for a widow who has married again to bear children resembling her first husband.

Various explanations have been offered to account for the facts observed, among which the theory of Mr. McGillivray, V.S., which is endorsed by Dr. Harvey, and considered (as we shall presently see) as very probable at least by Dr. Carpenter, seems the most satisfactory. Dr. Harvey says:

"Instances are sufficiently common among the lower animals where the offspring exhibit more or less distinctly over and beyond the characters of the male by which they were begotten, the peculiarities also of a male by which their mother at some former period had been impregnated. * * * Great difficulty has been felt by physiological writers in regard to the proper explanation of this kind of phenomena. They have been ascribed by some to a permanent impression made somehow by the semen of the first male on the genitals and more particularly on the ova of the female:[11] and by others to an abiding influence exerted by him on the imagination and operating at the time of her connection subsequently with other males and perhaps during her pregnancy; but they seem to be regarded by most physiologists as inexplicable.

Very recently, in a paper published in the Aberdeen Journal, a Veterinary Surgeon, Mr. James McGillivray of Huntley, has offered an explanation which seems to me to be the true one. His theory is that "when a pure animal of any breed has been pregnant to an animal of a different breed, such pregnant animal is a cross ever after, the purity of her blood being lost in consequence of her connection with the foreign animal, herself BECOMING A CROSS FOREVER, incapable of producing a pure calf of any breed."

Dr. Harvey believes "that while as all allow, a portion of the mother's blood is continually passing by absorption and assimilation into the body of the fœtus, in order to its nutrition and development, a portion of the blood of the fœtus is as constantly passing in like manner into the body of the mother; that as this commingles there with the general mass of the mother's own blood, it inoculates her system with the constitutional qualities of the fœtus, and that, as these qualities are in part derived to the fœtus from the male progenitor, the peculiarities of the latter are thereby so ingrafted on the system of the female as to be communicable by her to any offspring she may subsequently have by other males."

In support of this view, Mr. McGillivray cites a case in which there was presented unmistakable evidence that the organization of the placenta admits the return of the venous blood to the mother; and Dr. Harvey, with much force, suggests that the effect produced is analogous to the known fact that constitutional syphilis has been communicated to a female who never had any of the primary symptoms. Regarding the occurrence of such phenomena, Dr. Harvey under a later date says: "since then I have learned that many among the agricultural body in this district are familiar to a degree that is annoying to them with the facts then adduced in illustration of it, finding that after breeding crosses, their cows though served with bulls of their own breed yield crosses still or rather mongrels; that they were already impressed with the idea of contamination of blood as the cause of the phenomenon; that the doctrine so intuitively commended itself to their minds as soon as stated, that they fancied they were told nothing but what they knew before, so just is the observation that truth proposed is much more easily perceived than without such proposal is it discovered."[12]

Dr. Carpenter, speaking of phenomena analogous to what are here alluded to, says:

"Some of these cases appear referable to the strong impression left by the first male parent upon the female; but there are others which seem to render it more likely that the blood of the female has imbibed from that of the fœtus, through the placental circulation, some of the attributes which the latter has derived from its male parent, and that the female may communicate these, with those proper to herself, to the subsequent offspring of a different male parentage. This idea is borne out by a great number of important facts. * * As this is a point of great practical importance it may be hoped that those who have the opportunity of bringing observation to bear upon it, will not omit to do so."

In the absence of more general and accurate observations directed to this point, it is impossible to say to what extent the first male produces impression upon subsequent progeny by other males. There can be no doubt, however, but that such an impression is made. The instances where it is of so marked and obvious a character as in some of those just related may be comparatively few, yet there is abundant reason to believe, that although in a majority of cases the effect may be less noticeable, it is not less real, and demands the special attention of all breeders.

Whether this result is to be ascribed to inoculation of the system of the female with the characteristics of the male through the fœtus, or to any other mode of operation, it is obviously of great advantage for every breeder to know it and thereby both avoid error and loss and secure profit. It is a matter which deserves thorough investigation and the observations should be minute and have regard not only to peculiarities of form, but also to qualities and characteristics not so obvious; for instance there may be greater or less hardiness, endurance or aptitude to fatten. These may be usually more dependent on the dam, but the male is never without a degree of influence upon them, and it is well established that aptitude to fatten is usually communicated by the Short-horn bull to crosses with cattle of mixed or mongrel origin which are often very deficient in this desirable property.