( 782 ) 



2 /. 1 C. 2 P. 



2 i. 1 c. 2 m. 3 31. 



2 ;. 1 c. 2 m. 3 il/. 

 2 i. 1 C. 2 P. 



in which the teeth of tlie pcrniaiieiit set ol' teeth are written with 

 a Capital letter. 



For the majority of the phvl vrrhine Pi'iniates the following formula 

 holds true : 



This last formula is onl}' applicable to tlie family of Cebidae, 

 whereas the Hapalidae ditfer from tliera because they have a molar 

 less, so that the formula for their set of teeth becomes as follows: 



2 /. 1 C. 3 P. 



2 i. 1 c. 3 m. 2 M. 



2 i. 1 c. '6 m. 2 M. 

 2 I. I C. S P. 



The difference however in the set of teeth between Cebidae and 

 Hapalidae is for the present of less importance, the significance of 

 it will be shown later on. In the first place the attention should be 

 fixed on the principal difference between all platyrrhine Primates 

 on one side and all catarrhine ones on the other, i.e. the occurrence 

 of only two milkmolars and jn'emolars with these and of three milk- 

 molars and premolars with those. 



It is not dou!)tful that tlie set of teeth of catarrhine apes and of 

 man must be deduced from one that was composed like the set of 

 teeth of the now living Platyrrhines with tliree molai'S, so compared 

 with the set of teeth of those, the set of teeth of the catarrliine 

 Primates may be considered as reduced, the total numi)er of teeth 

 is larger with the former than with the latter. In what way has 

 tliis reduction of the set of teeth come about, this is a question 

 which has been frequently put and which has been answered in diffe- 

 rent ways. An obvious conception is certainly this, that a milkmolar 

 with his replacing tooth, the premolar, has become lost. But which 

 of the row has disappeared? This question has been answered in 

 different wa_ys. Whereas the Anthropologists in general are more 

 of the opinion that the last milkmolar and premolar have been 

 linked out, zoologists, palaeontologists and anatomists accept the view 



