ANOMALIES OF THE HUMAN DENTITION 157 



of this tooth. Since schizogenetic division is met with also in 

 the case of the central incisor it does not seem possible to accept 

 this explanation as altogether satisfactory. The extra tooth 

 figured in Fig. 55 may occur in the normal arch as repre- 

 sented in the present case or upon the palatal aspect of the cen- 

 tral incisor; it always assumes a stump-form with a curious 

 and typical crown. 



Fig. 55. — Extra median incisor in left upper jaw (European skull 503, W.R.U. / 

 The median and lateral incisors are of normal size and formation. 



Occasionally a condition of imperfect developmental separa- 

 tion of two teeth is met with in either the milk or the perma- 

 nent dentition (Fig. 56-A) or the germ of the upper lateral in- 

 cisor may be altogether absent. 



Very rarely has apparent duplication of the permanent ca- 

 nine been recorded. 



Sometimes small tooth masses have been observed in Man, 

 but more often in Anthropoids on the buccal aspect of the pre- 

 molars, both between these two teeth and between the second 



