THE PRIMATES — EXCEPT MAN 



131 



tion also occurs upon the premolar's. The first molar, especially 

 in the upper jaw, is often a little larger than the second, a con- 

 dition also occurring in Man. The third is variable in size and 

 pattern but tends to be smaller than the others. In the man- 

 dible the first molar does not present the marked contrast in 

 size with the second premolar so plainly apparent in Man. 

 The upper molars show a typical trigon with an oblique ridge 



Fig. 47. — Dentition of Chimpanzee (Pan sp., 9.88-16). A nearly adult female. 

 Note the slight development of crenations on the molars. The third molar is not yet 

 erupted. 



and a hypocone. In the last tooth however either the hypo- 

 cone or the metacone may be vestigial; or the tooth itself may 

 not erupt. The lower molars exhibit an antero-posterior diame- 

 ter longer than the transverse and the corners of the crown are 

 not so rounded as in Man. The hypoconid varies greatly. It 

 may be relatively larger than in Gorilla or it may be very 

 small and the entoconid increased in size so that the four prin- 

 cipal cusps meet in the center of the crown somewhat as they 



