WHALES DOLPHINS. 375 



the hand and arm of man, as is \vell shown in the wood- 

 cut here given of the anterior limb of the Porpoise. 



The bones of the arm are much shortened, those of the 

 wrist or carpus are closely united, and the fingers, which 

 are four or five in number, are remarkable for the number 

 of their joints, which sometimes, as in the second digit 

 of the Pilot-Whale, amounts to fourteen, whereas no 

 known mammal of any other order has ever more than 

 three. The hind limb may be said to be entirely wanting, 

 the pelvis being only represented by two slender bones 

 floating in the flesh and unconnected with the vertebral 

 column, while it is only in one group, the Balaenoid 

 ^Whales, that even a rudiment has been found of the bones 

 of the limb itself; in these some small bones and carti- 

 lages have been detected by Prof. Reinhardt, and subse- 

 quently by Prof. Flower, which are believed to be the 

 representatives of the femur and tibia. 



In respect to their dentition the members of this order 

 varies greatly, as will be presently noticed, but there are 

 never "milk-teeth" succeeded by a permanent set. The 

 breathing apparatus is very peculiar, and is difficult to 

 explain without the use of the technical language of ana- 

 tomy. The nostrils or " blow-holes " are placed on the 



