WHALES. 



373 



FlG. 412. Sl'EAKING THE NARWHAL. 



fabulous Unicorn. The narwhal, however, possesses the germ of two tusks, one on 

 each side ; but it rarely happens that both grow equally. Usually that on the left side 

 only is developed, and the other remains concealed in its socket. In general, this 

 animal is not more than twice or three times the length of its tusk. Its skin is marbled 

 with brown and white ; its blow-hole is at the top of its head ; and, instead of a dorsal 

 fin, it has a ridge running along the whole length of its back. 



SECTION II. TRUE WHALES. 



The True Whales have the head so large that it constitutes 

 one-third or even one-half of their length. The skull proper and 

 the brain have nothing to do with this extreme disproportion, 

 which is altogether owing to the enormous size of the bones of 

 the face. To this section belong 



The Cachalots (Physeter) *, generally called Spermaceti Whales. These 

 animals have a very voluminous head, enormously expanded, especially in front. 

 They have no whalebone nor any teeth in the upper jaw. Their letter jaw is 

 narrow, and armed on each side with a row of conical or cylindrical teeth, 

 which are received into corresponding cavities of the upper jaw when the 

 mouth is closed. The upper part of their prodigious head is occupied by large 

 excavations, or rather caverns, covered and separated by cartilaginous vaults, 



* <t>v<rr)Trip, physeter, a blower or bellows. 



