160 ZOOLOGY. 



closed and valvular state of the spout-hole, so well 

 calculated to oppose the entrance of water, must 

 necessarily be overcome by muscular power, and the 

 orifice of the nostril be expanded, to admit a full 

 volume of air at each inspiration : in fact, the Cachalot, 

 when gasping in the agony of death, will occasionally 

 expand the orifice of its spiracle to a great size. 



As compared with the huge bulk of the entire head, 

 the lower jaw of this whale appears diminutive, slender, 

 and not unlike the lower mandible of a bird. When 

 the mouth is closed, it is received within the soft parts 

 pendent from the border of the upper jaw, and is 

 nearly concealed by them. It is covered externally 

 with a smooth and firm skin, mottled black and white ; 

 but has no vestige of a lip. Its length averages eight 

 feet in the female, and from fourteen to sixteen in the 

 male. 



The tongue is small, and shaped much like that of 

 the ox ; it is of a grey- white or clay-colour on the surface, 

 and is composed, internally, of many fleshy bundles, 

 imbedded in a soft fat. It is incapable of protrusion, 

 and occupies so small a space in the back of the mouth 

 as to appear little more than a rudimental organ. The 

 capacity of the gullet, and expansive power of the jaws, 

 are both fully proportionate to the size of the animal. 



A very large proportion of the head of the Sperm 

 Whale is composed of soft parts, situated in front of 

 the cranium, and named by whalers the " junk " and 

 t( case." The junk is a solid mass of soft, yellow, 

 and oily fat, based on the upper jaw, and forming the 

 front and lower part of the snout : in a whale of large 

 size this part weighs between two and three tons, 



The " case" and its boundaries constitute the 

 upper and anterior portion of the head. The cavity 



