﻿176 



FIRST BOOK OF ZOOLOGY. 



A B 



Fig. 154. — Embryo Birds in Various Stages of Development.— ^4, Chipping Sparrow; 

 £, Petrel; C, Tern seen from above. 



If, now, the bones of the wing of an embryo bird be ex- 

 amined, the bones of the extremity of the wing, instead of 



humerus 



carpus 



metacarpus « 



phalanges -< 



Fig. 155. — Eight Wing of an Embryo Bird greatly enlarged. — Only a portion of 



the humerus is seen. 



