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

by S. L. Goodale

The hinny, on the other hand, the produce of the stallion and she ass, is essentially a modified horse. The ears are those of a horse somewhat lengthened; the mane flowing; the tail bushy, like that of the horse; the skin is finer, like that of the horse, and the color varies also, like the horse; the legs are stronger and the hoofs broad and expanded like those of the horse. In fact, in all these respects it is a horse somewhat modified. The body and barrel, however, of the hinny are flat and narrow, in which it differs from the horse and resembles the she ass.

A very curious circumstance pertains to the voice of the mule and the hinny. The mule brays, the hinny neighs. The why and wherefore of this is a perfect mystery until we come to apply the knowledge afforded us by the law before given. The male gives the locomotive organs, and the muscles are amongst these; the muscles are the organs which modulate the voice of the animal; the mule has the muscular structure of its sire, and brays; the hinny has the muscular structure of its sire, and neighs."

In connexion with these examples Mr. Orton refers to a special feature seen equally in the two instances, and which seems at first sight, a departure from the principle laid down by him. It is this, both hybrids, the mule and the hinny take after the male parents in all their external characters save one, which is size. In this respect they both follow the female parents, the mule being in all respects a larger and finer animal than its sire, the ass; the hinny being in all respects a smaller and inferior animal to its sire, the horse, the body and barrel of the mule being large and round, those of the hinny being flat and narrow; both animals being in these particulars the reverse of their respective sires, but both resembling their female parents.

In explanation of this seeming exception is adduced a well known principle in physiology, which is, that the whole bony framework is moulded in adaptation to the softer structures immediately related to it; the muscles covering it in the case of the limbs; and to the viscera in that of the great cavities which it assists in forming. Accordingly, in perfect accordance with the views above expressed, the general size and form which must be mainly that of the trunk, will be determined by the size and character of the viscera of the chest and abdomen, and will therefore accord with that of the female parents by whom the viscera in question are chiefly furnished.

The foregoing are the most important of Mr. Orton's statements. He gives, however, numerous additional illustrations from among beasts, birds and fishes, of which we quote only the following:

"The mule and the hinny have been selected and placed first, because they afford the most conclusive evidence and are the most familiar. Equally conclusive, though perhaps less striking instances, may be drawn from other sources. Thus, it has been observed that when the Ancon or Otter sheep were allowed to breed with common ewes, the cross is not a medium between the two breeds, but that the offspring retains in a great measure the short and twisted legs of the sire."

Buffon made a cross between the male goat and the ewe; the resulting hybrid in all the instances, which were many, were strongly characteristic of the male parent, more particularly in the hair and length of leg. Curious enough, the number of teats in some of the cases corresponded with those of the goat.

A cross between the male wolf and a bitch illustrates the same law; the offspring having a markedly wolfish aspect; skin, color, ears and tail. On the other hand, a cross between the dog and female wolf afforded animals much more dog-like in aspect—slouched ears and even pied in color. If you look at the descriptions and illustrations of these two hybrids, you will perceive at a glance that the doubt arises to the mind in the case of the first, 'what genus of wolf is this?' whereas in the case of the second, 'what a curious mongrel dog!'

The views of Mr. Walker in his work on Intermarriage, before alluded to, agree substantially with those of Mr. Orton, so far as regards crossing between different breeds; but they cover a broader field of observation and in some respects differ. Mr. Walker maintains that when both parents are of the same breed that either parent may transmit either half of the organization. That when they are of different varieties or breeds (and by parity of reasoning the same should hold, strongly, when hybrids are produced by crossing different species) and supposing also that both parents are of equal age and vigor, that the male gives the back head and locomotive organs and the female the face and nutritive organs—I quote his language: "when both parents are of the same variety, one parent communicates the anterior part of the head, the bony part of the face, the forms of the organs of sense (the external ear, under lip, lower part of the nose and eye brows being often modified) and the whole of the internal nutritive system, (the contents of the trunk or the thoracic and abdominal viscera, and consequently the form of the trunk itself in so far as that depends on its contents.)

The resemblance to that parent is consequently found in the forehead and bony parts of the face, as the orbits, cheek bones, jaws, chin and teeth, as well as the shape of the organs of sense and the tone of the voice.