THE ORDERS OF MAMMALS 



443 



numerous plates of whalebone, which are horny and frayed out 

 at the end. In feeding, the whale takes large quantities of water 

 into its mouth, and then forces it out through the sievelike 

 whalebone, retaining any small organisms that may have en- 

 tered with the water. 



The sulphur-bottom whale (Fig 311) is the largest of all whales 

 and the largest living animal, reaching a length of ninety-five 

 feet, and a weight of about 294,000 pounds; it inhabits the 



FIG. 311. Skull of Greenland whale showing whalebone. (From Sedgwick.) 



Pacific from California to Central America. The Greenland 

 whale, or bowhead, occurs in polar seas and reaches a length of 

 about sixty feet. One animal yields nearly three hundred barrels 

 of oil and about three thousand pounds of the best whalebone. 



Primates. The primates inhabit chiefly the warm parts of 

 the world. They are mostly arboreal in habit, and are able to 

 climb about among the trees because the great toe and thumb 

 are opposable to the digits, adapting the hands and feet for 

 grasping. A few primates lead a solitary life, but most of 

 them go about in companies. Fruits, seeds, insects, eggs, and 

 birds are the principal articles of food. One young is usually 

 produced at a birth, and it is cared for with great solicitude. 



The lemurs (Fig. 312) are quadrupeds and small or moderate 

 in size; they are covered with fur, and usually possess a long 

 tail. 



