118 NEW YORK ZOOLOGICAL SOCIETY 
1. Gorilla 5. Macacus 
2. Chimpanzee 6. Cynocephalus 
3. Orang-utan 7. Alouatta 
4. Gibbon 8. Hapale 
9. Lemur. 
A remarkable history of special adaptation, according to the 
life and habits of the several primates thus examined, is being 
revealed by this investigation, and at the same time the order 
of relation of the lower types to the higher apes and man has been 
established upon the fundamental grounds of the homologies of 
the central governing system of the body. There seems to be 
no doubt in the light of the definite results obtained that the 
gorilla stands nearest in its cerebral organization to man. The 
structural similarities between man and gorilla are so complete 
and striking that none but the expert would be able to detect 
the differences, even microscopically. The chimpanzee, orang- 
utan, and gibbon follow next in succession in the order named. 
In the lower primates very wide and significant differences of 
internal structure are observed, and each difference appears to 
be indicative of a highly specialized adaptation to habitat, mode 
of life and general environment. 
The work up to the present has as its main object the estab- 
lishment of the fundamental homologies of the primate brain 
stem, with the analytic interpretation of the modifications result- 
ing from the several divergent fines of environment adapta- 
tion. 
A series of papers is in preparation, to be published shortly in 
the Journal of Comparative Neurology, illustrated by drawings 
of the reconstructions of the brain stem, camera lucida and 
projection drawings of selected portions of the gray and white 
matter, and photographs of sections at forty critical levels 
through the brain stem of each species. 
Ultimately the results of the entire investigation will be 
brought together in the form of an atlas, giving the critical 
analysis of the Simian and Prosimian brain with relation to the 
evolution of the human brain. 
Respectfully submitted, 
GEO. S. HUNTINGTON, 
Prosector, N. Y. Zoological Society. 
January st, 92M. 
