CETACEA. 



487 



owing to tlie 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 m the 

 upper jaw. Theu- lower jaw is narrow, and armed on each side with 

 a row of conical or cylindrical teeth, which are received into corre- 

 sponding 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, and 

 tilled with an oil that crystallizes as it cools into the substance well 

 known in commerce by the name of Spermaceti. The cavities in which 

 the spermaceti is lodged have nothing to do with the real skull, 

 which is rather small, placed beneath them, and contains the brain 

 in the usual manner. From the head of a single Cachalot are ob- 

 tained from eighteen to twenty barrels of fluid Spermaceti. The 

 usual length of this gigantic Cetacean is upwards of seventy feet, 

 and its circumference at the largest part fifty-two feet. 



The Whalebone Whales {Balsena f) are provided with heads of 

 enormous magnitude in proportion to the size of their bodies, but not 

 much expanded in front, and they have no true teeth. Their upper 

 jaw has both its sides furnished Avith thickly set plates composed 



Fig. 414.— whale fishery. 

 of a peculiar horny sul)stance called Whalebone. These plates are 

 thin and fringed at theh margin, forming a kind of sieve, that serves 

 to retain the small animals on which these gigantic creatures live. 



* (pv(r7]Tr]p, physeter, a Uoioer, or helloios. 

 t Balrena, a idude. 



