The Skull III 
of the jaws with the many rows of teeth, and we may 
now guess that they were attached so loosely to the skull 
that the action of the water washed them away with 
the flesh. This was the case, and in all fishes we find 
both jaws as separate bones. Among reptiles we find 
the quadrate bone free only in snakes, an admirable 
adaptation which enables them to swallow their prey 
entire. 
The bones forming the palate, or roof of the mouth, 
are of the greatest value in classification. No matter 
how specialized the habits or the food of a bird may be, 
the palate appears to be the last portion of its structure 
to respond to any recent outside influences. Thus while 
the absence or presence of a keel to the sternum is a 
character of little value in separating the ostriches and 
their allies from all other birds, yet the radical differ- 
ence shown by the palate bones in the two groups is 
reliable evidence of their early divergence from each 
other. These taxonomic characters may be found in 
any good book on systematic ornithology and need 
not detain us here. 
Although we have the skull and both jaws of our 
chicken, yet some very important and interesting bones 
are lacking, and to find them we must find the tongue 
of the bird. For a bird’s tongue, as well as that of other 
creatures, is not all flesh or horn, but underneath there 
is a jointed framework of bone, which is called the hyoid. 
We may compare its shape to that of an arrow, with a 
central head and four barbs, two very short and blunt 
and two long jointed ones. 
