374 



ZOOLOGY 



modern birds are without teeth, very ancient fossil 

 forms are known in which the jaws have numerous 



Feathers 



From Owens 1 "Comparative Anatomy " 

 FIG. 151. Young blackbirds, showing the developing feather tracts. 



sharp teeth like those of a reptile. The wings are of 

 course modified anterior limbs, as may be seen by com- 

 paring the bones with those of other animals. Thus 

 the beautiful idealistic paintings of angels, in which 

 these beings are represented with human arms and 

 hands, and in addition birdlike wings, are contrary to 

 the teachings of anatomy. The anatomist prefers the 

 winged sandals of Mercury, which do not offend against 

 his science. 



2. Feathers are not scattered over the bird at random. 

 Mr. C. W. Beebe figures the sprouting feathers of a 

 12-day embryo chick, and it can be seen that they are 

 arranged in rows crossing each other X-wise, just as the 

 scales of a fish. In the penguins, probably the most 

 primitive of living birds, the feathers grow on all parts 

 of the body, but in other birds they occupy definite 

 areas. These feather tracts can be observed when the 

 bird is plucked and the points of attachment become 

 visible ; since they differ in the various groups of birds, 

 they are of assistance in classification. Although the 



