Fig. 53. — Pelvic vertebrae of young Alligator. 



Fig. 54. — Pelvic vertebrae ol American Flamingo. 



Fig. 55.— Pelvic vertebrae of Bald Eagle. In the reptile, where there is no need 

 for rigidity, only two typical pelvic vertebrae are joined together; in the birds 

 many dorsal and caudal vertebrae are joined with these to make a rigid frame 

 for flight and for bipedal locomotion. 76 



