174 ABSENCE OF TEETH IN WHALE, ANT-EATER, 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. 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 
Kuminant 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 
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, 
Fig. 103.— Skull of the Ant-eater. 
