256 THE DENTAL SYSTEM OF THE PRIMATES [SECT. A 



The dental system in certain Cebidae, in the Simiidae, and in 

 the Hominidae is liable to a considerable degree of numerical 

 variation ; thus as many as 4 °/ of examples of Cebus and Ateles, 

 and 8°/ among the Simiidae present instances of supernumerary 

 teeth. Detailed accounts are provided by Bateson (M aterials for 

 the Study of Variation), Magitot {Anomalies du Systeme dentaire), 

 and in the exhaustive records, with an extensive bibliography 



Fig. 189. Accessory upper tooth behind the first molar of a Chimpanzee. 

 (Liibeck Museum.) 



collected by De Terra (Beitrdge zu einer Odontographie der 

 Menschen-Rassen. Inaugural Dissertation, Zurich, 1905). 



CANINE TEETH. 



The canine teeth may be considered first. Few numerical 

 variations are recorded here. A remarkable case of reduplication 

 of the upper canine' tooth on one side may be seen in the skull of 

 an adult Gorilla in the Hamburg Museum. There is no question 

 of the retention of the deciduous canine tooth in this case. 

 Hrdlicka (Proc. of the United States National Museum, Vol. XXXI. 

 p. 560) figures a precisely comparable example in the lower jaw 

 of an Orang-utan. 



