118 NEW YORK ZOOLOGICAL SOCIETY 



1. Ciorilla 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 dift'erences, 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 Tines 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, 

 Pro.'^ecfor, N. Y. ZooUxjical Society. 

 January 1, 1921. 



