176 



FIRST BOOK OF ZOOLOGY. 



A E C 



FIG. 154. EMBEYO BIKDS IN VARIOUS STAGES OF DEVELOPMENT. A, Chipping Sparrow ; 



E, Petrel ; (?, 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 



hwnerus 



carpus . 



metacarpus 



phalanges* 



FIG. 155. EIGHT WING OF AN EMBRYO BIRD GREATLY ENLARGED. Only a portion oi 



the humerus is seen. 



