The species which throw most light on this theme are the Gorilla, the Chimpanzee and the Orang-utan. Of these the Chimpanzee has most in common with the human race. But it may satisfy the qualms of many to know that between the Ape and the Man there is a great gulf fixed. The brain of the largest Ape is less than half the size of that even of the lowest of mankind. Man is a reasoning, and for the most part a reasonable, creature; he is a tool-making animal. This is more than can be said of any of the apes, even the most intelligent. Their teeth and immensely powerful arms must serve their every need. No ape ever fashioned for himself either a knife, a vessel to carry water, or any means of transport; and herein we have a measure of his brain capacity. The huge jaws and great canine teeth are no less conspicuous “marks of the beast.” These, however, man himself has but recently lost, as was proved by the sensational discovery of the skull of an ape-like man at Piltdown, in Sussex, during 1912. Herein the jaw was essentially that of an ape, while the base of the skull was as markedly human. The cheek teeth, or molars, were of the human type; but the canine was ape-like, though much inferior in point of size. That the men of this remote age—which was possibly that of Pliocene times and certainly not later than early Pleistocene—had begun to use rudely-fashioned tools, is proved by the roughly-chipped flints found with the remains. With the invention of tools the decline in the size of his “eye” teeth began.