338 STRUCTURE AND ADAPTATION OP TEETH 

 Mr. Mummery read the concluding portion of his paper^ 



On the Structure and Adaptation of the Teeth in 

 the Lower Animals, and their Relations to the 

 Human Dentition. 



In this, tlie concluding portion of my paper, 

 we will consider the dentition of the Quadrumana, 

 which, of all the lower animals, approach most 

 nearly to the human species in organization. 



We observe in the several genera a graduated 

 series from the insectivorous modification of the 

 teeth in the lemurs up to the dentition of the 

 orang and chimpanzee, in. which animals the teeth 

 exhibit the same number and general forms as in 

 man. 



In the lemurine section the number of lower 

 incisors varies from two to six, and they generally 

 slope forward in a nearly horizontal direction; 

 but the upper incisors are four in number. 



The canines attain different degrees of develop- 

 ment in the various species. There are usually 

 three premolars in each series, which, with the 

 three molars, are furnished with sharp cusps, 

 locking into those of their antagonists, as in the 

 true Insectivora, and the temporal fossa is con- 

 tinuous with the orbit. 



In the second section, comprehending the broad- 

 nosed American monkeys, we may instance the 

 spider-monkeys, whose long prehensile tail serves 

 as a fifth organ of locomotion. In these animals 

 the dentition approaches nearer to the higher 



