In the early part of this work I mentioned, that from the observations of horse-breeders it was the general received opinion, that the male had more influence upon the offspring: than the female; and I then suggested some reasons which it rendered to me very doubtful, but experiments and observations have since convinced me, that the fact does not only hold good with respect to horses, but also in the human race, and in every species of animals, that the male has infinitely more influence on the exterior form of the young than the female, and that he in fact is the type of the race. Nor does the remark I have made, that the females constitute the unity of the species in the least controvert this position, because that cannot be extended further than her possessing the greater facility in representing the species, but this point is more amply discussed in this work under the article Mule; from which it will appear, that notwithstanding the female may have more influence on the character of the breed, yet from her it never receives any improvement, which faculty is solely possessed by the male. THE ASS. If we consider this animal with attention, he appears only to be a horse degenerated. The perfect similitude in conformation of the brain, lungs, stomach, intestinal conduit, heart, liver, and other viscera, and the great resemblance of the body, legs, feet, and the entire skeleton, supports this opinion. We may also attribute the slight differences, which are found between these two animals, to the influence of the climate and food, and to the fortuitous succession of many generations of small wild horses, which, gradually degenerating, have at last produced a new and fixed species; or, rather a succession of individuals alike, all vitiated in the same manner, sufficiently differing from a horse, to be looked upon as another species. What appears to favour this idea is, that horses vary much more than asses in their colour; they have consequently been longer domestic, since all domestic animals vary much more in their colour than wild ones of the same species. The greater number of wild horses, of which travellers speak, are small, and have, like the ass, grey hair, and the tail naked and frizzled at the end: there are also some wild horses, and even domestic ones, which have a black stripe on the back, and other marks, which nearly resemble both wild and domestic asses.