Page:Popular Science Monthly Volume 40.djvu/696

676 dealt with, in this paper, have a most important bearing on the argument on which he was then laying most stress, viz., that man is descended from an arboreal quadrumanous ancestor. The fact that such important and easily ascertained characteristics as those alluded to should have been passed over by one so keenly observant of all phenomena bearing upon his theory might suggest that the great man was scarcely so supreme in his own nursery as he was in the wider field of research, and that his opportunities for investigation were to some extent limited by the arbitrary and inflexible rules of this household department. In fact, the supposed interest of the Darwinian race, when conflicting with the interests of the Darwinian theory, appear to have become paramount somewhat to the detriment of the latter.

It has been well said that the development of the individual from the single germ-cell to maturity is an epitome of the infinitely longer development of the race from the simplest form of life to its present condition. No branch of science, not even paleontology, has thrown so much light on the evolution theory as the study of the structure and progress of the embryo up to the time of birth. There seems, however, no reason why embryology should stop here. An animal until independent of parental care, and even beyond that point, until the bodily structures and functions are those of an adult, is still, strictly speaking, an embryo; and we may learn much of its racial history by observing the peculiarities of its anatomy and habits of life.

For instance, among our domestic animals, horses and cattle live very much in the same manner, and thrive equally well grazing in open pastures. Yet a brief examination of the young of each shows that the habits and habitats of their respective wild ancestors were widely different. A foal from birth is conspicuous for the development of its legs, and when a few days old can gallop almost as fast as ever it will in its life. It makes no attempt at concealment beyond retiring behind its dam, and it carries its head high, evidently on the alert to see danger and flee from it. A young calf, on the contrary, is not much longer in the leg in proportion than its parents (I exclude, of course, the breeds artificially produced within quite recent times), and has but an indifferent turn of speed, and it is slow and stupid in noticing its surroundings. It has, however, one powerful and efficient instinct of self-preservation; for if, as is often the case in a bushy pasture, the mother leaves it under cover while she goes to graze, it will lie as still as death, and allow itself to be trodden on rather than betray its hiding-place. Hence we see that the ancestors of our domestic horses inhabited open plains where there was little or no cover, and that they escaped by quickly observing the approach of a foe and by speed. Wild cattle, on the contrary, as is still