4 68 



MANUAL OF ZOOLOGY 



SECT. 



ill 



parallel. Neither ischium nor 

 pubis unites ventrally with its 

 fellow to form a symphysis. 



In the hind-limb the femur 

 (Fig. 267, fe) is a comparatively 

 short bone. Its proximal ex- 

 tremity bears a prominent 

 trochanter (tr) and a rounded 

 head (hd). Its distal end is 

 produced into pulley-like con- 

 dyles. Articulating with the 

 femur is a very long bone, the 

 tibio-tarsus (ti.ts) its distal 

 end is pulley-like, not con- 

 cave like the corresponding 

 extremity of the tibia of 

 other Amniota. The study of 

 development shows that the 

 pulley-like distal end of the 



bone (Fig. 268, tl.i) consists of the proximal tarsals 

 which at an early period unite with the tibia and give 

 rise to the compound shank-bone of the adult. 



FIG. 265. Columba livia. Left manus 

 of a nestling. The cartilaginous 

 parts are dotted, cp.i, radiale ; 

 cp. 2, ulnare ; mcp. i. 2, 3, meta- 

 carpals \ph.i, phalanx of first digit ; 

 ph.2, ph.2\ phalanges of second 

 digit ; ph-3) phalanx of third digit ; 

 ra. radius ; id. ulna. (From 

 Parker's Zootomy.) 



FIG. 266. Columba livia. Left innominate of a nestling. The cartilage is dotted. 

 ac. acetabulum ; a. tr. anti-trochanter ; //. pre-acetabular, and //'. post-aceta- 

 bular portion of ilium ; is. ischium ; /. s.f. ischiatic foramen ; ob.f. obturator 

 notch ; pu. pubis. (From Parker's Zootomy.) 



