ZOOLOGY. 357 



difference in the development of particular teeth, were affirmed to be 

 primitive and unalterable specific peculiarities of man. The difference in 

 the time of disappearance of the suture separating the pre-maxillary from 

 the maxillary bone was not explicable on any of the known causes affect- 

 ing such character. Teeth, at least such as consisted of the ordinary den- 

 tine of mammals, were not organized so as to be influenced in their growth 

 by the action of neighboring muscles ; pressure upon their bony sockets 

 might affect the direction of their growth after they were protruded, but 

 not the specific proportions and form of the crowns of teeth of limited 

 and determinate growth. The crown of the great canine tooth of the male 

 Troglodytes gorilla, a large African ape, began to be calcined when its diet 

 was precisely the same as in the female, and when both sexes derived 

 their sustenance from the mother's milk. Its growth proceeded, and was 

 almost completed before the sexual development had advanced so as to 

 establish those differences of habits, of force, and of muscular exercise, 

 which afterwards characterized the two sexes. The whole crown of the 

 great canine tooth Avas, in fact, calcined before it cut the gum or displaced 

 its small desiduous predecessor ; the weapon was prepared prior to the de- 

 velopment of the forces by which it was to be wielded ; it was therefore a 

 structure foreordained, a predetermined character of the chimpanzee, by 

 which it was made physically superior to man ; and one could as little 

 conceive its development to be a result of external stimulus, or as being 

 influenced by the muscular action, as the development of the stomach, the 

 testes, or the ovaria. There was the same kind of difficulty in accounting 

 for the distinctive characters of the different species of the orangs and the 

 chimpanzees as for those more marked distinctions that removed both 

 kinds of apes from them. And, with regard to the number of the known 

 species, it was not without interest to observe that, as the generic form of 

 the quadrumana approached the bimanous order, they were represented 

 by fewer species. The professor then proceeded to demonstrate the unity 

 of the human species by the constancy of those osteological and dental 

 characters to which attention had been more particularly directed in the 

 investigation of the corresponding characters in the higher quadrumana. 

 Man was the sole species of his genus, the sole representative of his order; 

 he had no nearer physical relations with the brute kind than those which 

 arose out of the characters that linked together the great group of placental 

 mammalia called " unguiculata." In conclusion, the professor briefly 

 recounted the facts at present satisfactorily ascertained respecting the com- 

 parative antiquity of the quadrumana and of man upon the surface of the 

 earth. At the time of the demise of Cuvier, in 1832, no evidence had 

 been obtained of fossil quadrumana, and the baron supposed that both 

 these and the bimana were of very recent introduction. Soon after the 

 loss of that great reconstructor of extinct species, evidence with regard to 

 the fossil quadrumana was obtained from different quarters. In the oldest 

 tertiary deposits in Suffolk, specimens of jaws and teeth were found that un- 

 mistakably indicated the former existence of a species of monkey of the genus 



