WCP1585

[1]¹

5, Westbourne Grove Terrace, W.

Tuesday May 24^th [1864].²

My dear Sir

Many thanks for your note & kind criticisms on my little paper.³

I mentioned the missisippi [sic] crania because I understood that they were decidedly of the same type as the modern Indians’. I sh[oul]^d have said ^{"infancy of"} "Indian race" instead of "human race".

With regard to the "antiquity of man" I will make a few observations. First, I argue rather for the possibility than the necessity of his having [2] existed in Miocene times; & I still think so, because this is a question not to be judged of by any positive measure of time (we can^not tell à priori⁴ whether ten million or a thousand million of years would be required for any definite change in man) but ^only but by a comparison ^with of the ^{rate of} change of other animals.

Now several existing genera lived in the Miocene age (Rhinoceros[,] Tapir &c.) & other ^{as well as} anthropoid apes allied to Hylobates. But Man is even by Huxley⁵ classed as a distinct family; — that family therefore must probably date back from [3] the Eocene period, if not earlier.

Now the greater portion of this family difference is manifested in the head & cranium. A being almost exactly like man in skeleton but with a cranium as little developed as a chimpanzee’s would certainly not be made a distinct family of, — only a distinct genus.

My argument therefore is, that this great cranial difference has been developing while the rest of the skeleton has remained nearly stationary; & while the ^Miocene Dryopithecus has been modified into the modern Gorilla, speechless & ape-brained man, (but still man) has been developed into existing [4] large-brained talking ^{intelligent speech-forming} man.

The Pliocene mammals on the other hand are in a great measure of existing genera, — and as my whole argument is to show how man has undergone a generic change in brain & cranium, while the rest of the body has hardly changed specifically, I cannot consistently admit that all this has been brought about in a less period than has sufficed to change most other mammals generically, except by assuming that he has changed more rapidly, which may indeed have been the case, but which we have no evidence yet to prove.

My paper was written far too hastily & too briefly fully to explain the subject.