Prof. Huxley furnished to Mr. Darwin a very learned note, in which he stated the results of all that is now known concerning the resemblances and differences in the structure and the development of the brain in man and the apes. The differences may be laid aside in the present discussion, because it is not necessary, for my present purpose, to found anything upon them. But the resemblances, just as they are stated by the eminent anatomist, without regard to controverted details, are the important facts to be considered. The substance of the whole comparison is that the cerebral hemispheres in man and the higher apes are disposed after the very same pattern in him as in them; that every principal "gyrus" and "sulcus" of a chimpanzee's brain is clearly represented in that of a man, so that the terminology which applies to one answers for the other; that there is no dispute as to the resemblance in fundamental character between the ape's brain and man's; and that even the details of the arrangement of the "gyri" and "sulci" of the cerebral hemispheres present a wonderfully close similarity between the chimpanzee, orang, and man.[76] These are said to be the result of a comparison of the adult brain of man and the higher apes; and, although it is claimed by some anatomists that there are fundamental differences in the mode of their development which point to a difference of origin, this is denied by Huxley, who maintains that there is a fundamental agreement in the development of the brain in man and apes. His views of the facts for the purpose of the present inquiry may be accepted without controversy, not only because he is an authority whose statements of facts I am not disposed to dispute, but because it is not necessary to dispute them. What, then, do they show?