460 



DE. H. W. MARETT TIMS OK THE 



these specimens is whether there is any evidence of the previous 

 existence of additional teeth, and in this connection there are 

 two points which may be mentioned. 



(i.) In the incisor region of the upper jaw the dental lamina 

 between i^^ and c. maintains a position extending well down into 

 the substance of the jaw, and does not shorten up as it does 

 between any two of the other teeth. Midway between these 



Yig. 6. — Section through the region posterior to the Third Upper Incisor 

 of a 12 hours' Pup, showing apparent vestigial Fourth Incisor. 



teeth there is a slight enlargement, somewhat forked (fig. 6, i.*), 

 which only extends through a few sections. The position of the 

 dental lamina might be explained by the great development of the 

 canine retaining it deeply in the jaw ; but if it were due to this, 

 one would expect to find the same condition behind the canine 

 as well, which is not the case. It is possible that there is here 

 present the vestigial remains of a fourth upper incisor, though 

 the facts are not conclusive. 



