And it is not true, as is commonly supposed, that, after all other resemblances between the human and anthropoid structures have been made out, there still exists somewhere some undistinguishable difference in the organic structure of their brains. All differences in structure from time to time suspected or asserted to exist between the brain of man and that of the man-like apes have been one after another completely swept away. And it is now known to all neurologists that the human and anthropoid brains differ structurally in no particulars whatever, both of them containing the same lobes, the same ventricles and cornua, and the same convolutional outline. Even the posterior lobe, the posterior cornu, and the hippocampus minor, so long triumphantly asserted to be characteristic features of the human brain, have been pitilessly identified in all anthropoids by the profound and terrible Huxley. There is not an important fold or fissure in the brain of man that is not found in the brain of the anthropoid. ‘The surface of the brain of a monkey,’ says Huxley, ‘exhibits a sort of skeleton map of man’s, and in the man-like apes the details become more and more filled in, until it is only in minor characters that the chimpanzee’s or the orang’s brain can be structurally distinguished from man’s’.[7] The great difference physically between man and the anthropoids, aside from man’s talented larynx and erect posture, lies in man’s abnormal cranial capacity. The normal human cranium never contains less than 55 cubic inches of space, while the largest gorilla cranium contains only 34½ cubic inches. This is a difference of 20½ cubic inches. And 20½ cubic inches of thinking matter is an alarming amount to be lacking in a single individual. But this cranial gap between gorilla and man is deprived of some of its significance by the fact that human crania sometimes measure 114 cubic inches, making a difference between the smallest and largest human brains of 59 cubic inches. The difference between the gorilla and the savage in cranial capacity is, therefore, _only about one-third as great as the cranial chasm between the savage and the sage_. 1. The bat and a few other animals have a disc-like placenta, but it develops into the disc shape by a different route from what it does in the primates. 2. Hartmann: _Anthropoid Apes_; New York, 1901. 3. Quatrefages: _The Human Species_; New York, 1898. 4. Tyler: _Anthropology_; New York; 1899. 5. Haeckel: _History of Creation_, 2 vols.; New York, 1896. 6. Haeckel: _The Riddle of the Universe_; New York, 1901. 7. Huxley: _Man’s Place in Nature_; New York, 1883. V. Recapitulation.