BONES OF THE LEG AND WING OF BIRDS. 



lit 



being closely welded together as in Fig. 153, are found to 

 be separate, and the carpal bones, of which only two were 

 apparent in the full-grown wing, are now separate and four 

 in number. The wing at this stage looks more like a three- 

 toed foot. Fig. 155 shows the appearance of the wing of an 

 embryo bird. 



As the bird develops, the bones of the fingers gradually 

 approach and some of the bones grow together till they 

 present the appearance shown in Fig. 153. 



158. The bones of the leg grow together in the same way. 



tarsus J^ 



Tnetaiarsus 



Jfia. 166.— BosES or thb Eight Leg or an Adult Bied. — Only the lower portion oi 

 the tibia and fibula is drawn. 



