174 ABSENCE OF TEETH IN WHALE, ANT-EATEB, ETC. 



draws water in enormous quantities, whenever it is in want 

 of food ; and in this manner it strains out, as it were, the 

 minute gelatinous animals upon which it lives, from the water 

 of the seas it inhabits. The water thus taken in is expelled 

 from the nostrils or blow-holes, which are situated at the top 



Fig. 102. SKULL OF WHALE. 



Fig. 101. WHALEBONE. 



of the head. Most of the Whale tribe have short fringes of 

 this kind in the roof of the mouth ; but in none, except the 

 Balcena, or Greenland Whale, is it long enough to make it 

 worth separating ; all the other species having teeth, either in 

 one or both jaws. It is a curious fact, that the rudiments of 

 teeth may be discovered in both jaws of the young Greenland 

 whale, although they are never to be developed. And the 

 rudiments of incisor teeth in the upper jaw, and of canine 

 teeth in both jaws, may also be discovered in the young of the 

 Ruminant quadrupeds (oxen, sheep, &c.), though they never 

 show themselves above the gum. 



186. The Ant-eaters, also, are destitute of teeth, and usually 

 obtain their food by means of their long extensible tongues, 



which are covered with a viscid 

 saliva; this being pushed into 

 the midst of an ant-hill, and 

 then drawn into the mouth, 

 brings into it a large number 



Fig. 103. SKULL OF THE ANT-EATER. 5? . , , . , 



of these insects, which are 



sufficiently bruised between the toothless jaws (fig. 103). 

 Lastly, may be mentioned as a curious exception to the general 

 rules respecting the teeth of Mammalia, the remarkable Orni- 

 thorhyncus of New Holland (ZOOLOGY, 317), which feeds, 



