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 onh' 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, 3'et the radical differ- 

 ence shown by the palate bones in the two groups is 

 reliable evidence of their earl}^ 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. 



