108 



THE REASON WHY: 



With snow, frost, hail, and sleet, and found stern winter strong, 

 With mighty isles of ice, and monsters huge and strong.&quot; DRAYTCN. 



335. Why has the walrus large tusks descending from its 

 upper jaw ? 



These tusks consist of an enlargement of the canine teeth, which 

 in the carnivorous tribes are chiefly employed to capture and 

 kill the prey upon which they subsist. 



They are thus enlarged in the walrus to enable the animal to 

 mow down, or to throw aside, the great fields of sea-weeds arnom* 

 which it finds crustaceous and molluscous animals, such as lobsters, 

 crabs, shell-fish, &c., upon which it feeds. 



They are also useful to enable the animal, the body of which 

 is cumbrous and heavy, to clamber over the blocks of ice, among 

 which it lives. This it accomplishes by fixing its tusks in the 

 ice, using them as a lever to assist its movements. They enable 

 the animal to raise itself out of the water, by holding on upon 

 the rock or iceberg, just as the parrot steadies himself by its 

 bill. The tusks are also used as weapons of defence. 



ORDER, IV. MARSUPIALIA. 



336. Why are kanguroos, opossums, &c., included in the order 



Marsupialia ? 



Because they are distinguished 

 by a pouch-like appendage on 

 the under-part of the females, 

 which pouch is supported by 

 two peculiar bones called Mar 

 supial from the Latin word 

 Marsupium, meaning a purse 

 or pouch. 



337. Why are these animah 

 provided with pouches ? 



Because their young are born 

 in a very helpless state. They 

 are far more minute and formless 

 t&amp;gt;han the young of any other ol 



