The Framework of the Bird 87 
recognize in these primitive types the wish-bone of our 
Christmas turkey. 
In terrestrial quadrupeds and birds we usually find 
the front limbs near the front part of the body and the 
hind limbs much farther back, but it is interesting to 
Fig. 61.—Girdle of a bony fish. 
notice that in the fish, Fig. 61, all four limbs or fins are 
very far forward, almost or quite in the head region 
itself. This is a result of the function of balance which 
these structures almost wholly perform, the fin of the 
tail furnishing the locomotive power. 
It is very interesting to notice how many bones have 
kept to their respective places in the evolution of animals, 
