318 MAMMALS 



skin and skull, on the right side of the massive head is a 

 large cavity containing the substance known as spermaceti, 

 formerly used to a great extent in the manufacture of 

 candles. The nostrils open by a single aperture through 

 the top of the head. This opening is the " blow hole " and 

 from it issue the columns of vapor sent forth by the animal 

 when respiring. These huge animals come to the surface, 

 "spout" — send forth moisture-laden columns of vapor 

 from the lungs — sixty to seventy times, then plunge below 

 to remain from forty minutes to an hour and a quarter. 



There are several species of whalebone whales, but the 

 bowhead, or Greenland whale is best known for its oil and 

 whalebone. It has no teeth, but the lower sides of the 

 upper jaw are furnished with hundreds of parallel plates of 

 baleen, or whalebone. These plates are fringed at the end 

 and act very effectually as a strainer, to separate the small 

 animals, upon which the whale feeds, from the water taken 

 in with them. The right whales of the Arctic Seas, the 

 razor-back whales, and the sulphur-bottom whalfes are 

 the largest living mammals. The latter are often ninety 

 to ninety-five feet in length. The whales possess mammae 

 and suckle their young; but, superficially, they resemble 

 fish more than mammals. The fore limbs are modified into 

 paddles, while the hind limbs are wanting, and the body is 

 incased in a thick layer of fat, the " blubber," which yields 

 the oil so much sought after. 



Manatee and Ddgong (Sirenia) 



These are also aquatic mammals with a fishlike body and 

 only the forward, paddlelike limbs present. There is no 

 vertical dorsal fin and the snout is not greatly elongated. The 



