248 



MAMMALIAN DENTITION 



like canines this tooth somewhat resembles in function the lower 

 canine since it also forms a shear with the upper canine. In 

 the Chimpanzee on the other hand and still more in Man the 

 canines are reduced and the first lower milk molar possesses 

 an ever increasing tendency to become molariform. 



From this brief review and from what we know of the his- 

 tory of the human milk dentition we may conclude that con- 

 siderable specialization has occurred in the human milk molars, 



Fig. 90. — Deciduous dentition of Orang (Pongo pygmaeus, Hoppius; 9.88-7). 



especially in the first, adapting them to the needs of the or- 

 ganism, and further that analogous specialization can be ob- 

 served in differing degrees in the Anthropoid Apes according 

 to their requirements, the specialization affecting the several 

 teeth in varying measure. But in spite of the superposed 

 adaptive features, quite pronounced though they may be, 

 certain primitive and ancestral characters are not entirely 

 overshadowed. 



