CETACEANS. 163 



those occupying the extremities of the series. Many of 

 them, placed most posteriorly, are in fact very small, 

 and but little raised above the gum, (to which they are 

 alone attached,) even in large and aged whales. 



Their number varies greatly in different individuals, 

 and does not appear to be influenced by either age, sex, 

 or size. Amongst many Cachalots, I found their varia- 

 tions in number to be as follows : 2 1 on one side of 

 the jaw, 20 on the opposite, 23-21, 22-22,24-25, 22-23, 

 24-26, 23-24, 22-24, 19-20 ; or from thirty-nine to fifty. 



The upper jaw is not altogether toothless, as usually 

 described. On the contrary, it has on either side a 

 short row of teeth, which, for the most part, are placed 

 more interior than the depressions which receive the 

 teeth of the lower jaw ; though they sometimes, also, 

 occupy the bottom of those cavities. Their entire 

 length is three inches ; they are curved backwards, and 

 elevated about half an inch above the soft parts, in 

 which they are deeply imbedded, having only a slight 

 attachment to the maxillary bone. In two instances, I 

 found their number to be eight on each side. They 

 exist in both sexes of the Sperm Whale ; and although 

 visible externally only in the adult, they may be seen 

 in the young animal upon removing the soft parts from 

 the interior of the jaw. 



Although these palatine teeth are perfect in their 

 structure, their relatively small size will not permit us 

 to regard them as more than rudimental.* 



In a half-grown male, about thirty-five feet in length, 

 the teeth of the lower jaw are not larger than in the 

 adult female; but are much more symmetrical and 



* Some of these teeth, from the upper-jaw of an adult female 

 Cachalot, I have deposited in the museum of the Royal College of 

 Surgeons in London. 



M2 



