SKELETON 



863 



variable in extent, being comparatively largest in the Gallinse and 

 some of the Cuculi and Musophagidx, while it is hardly indicated in 

 many Grues, Ciconiai, Phoenicopferus, Columhai, Lari, Psittaci, Pucerotidie 

 and Passeres. It may grow wholly from the pubis, or from that 

 and the ilium, or in extreme cases from the last only. 



The Posterior Limbs or Legs, like the anterior, are composed 

 of three principal portions (1) the Femur, which has been 

 already mentioned (pages 248, 249), and the figures here intro- 

 duced will shew some of its more important features ; (2) next the 

 Tibia and Fibula ; and lastly (3) the bones of the Feet. The 

 proximal end of the Tibia has two facets, of which the inner is 

 concave and articulates with the inner condyle of the Femur, 

 wdiile the outer is convex, and partly fits into the intercondylar 

 sulcus and partly articulates with the inside of the outer femoral 

 condyle. It also supports the Fibula. From the anterior surface 

 of its upper end arises a crest formed by two ridges, of which the 

 inner is generally the more prominent. They serve for the origin 

 of part of most of the extensor muscles of the leg, the tendon of 

 the chief of which, 7nusc. femori4ibialis, is inserted on the upper 

 part of the crest, and within this tendon is intercalated the patella 



(page 698). In Colijmhu& 

 and Podicijjes is developed 

 a long triangular process 

 which stands high above 

 the head of the tibia, and 

 in the latter the almost 

 equally - high triangular 

 patella rests with its base 

 on the intercondylar 

 femoral sulcus, and its 

 whole side against the 

 outer surface of the crest. 

 On the outer side of the 



tibia is the peroneal ridge ^^-^ 



T. m. 



>Fo. 



.H-//, 



C.e. 



serving for a lateral attach- 

 ment to the Fibula, the 

 fusion of which with the 

 Tibia is generally indicated 

 by a similar ridge situated 

 further down. The distal 

 end of the Tibia is com- 

 pletely fused with several 

 of the proximal tarsal bones, which form an inner and an outer 

 condyle, separated by a sulcus, and articulate with the " tarso- 

 metatarsus." On the anterior surface a little above the sulcus just 



Pavo cristatus, Left Femur, back, outer uud 

 front view. 

 Bi. Loop for Biceps cruris ; C.e. CA. exterior and interior 

 Condyles ; F.p. Fossa poplitea ; Fib. Fibular facet ; f.t. 

 Femoro-tibial attachment ; Fo. Pneumatic foramina ; 

 Ga. Gastrocuemial tendons ; H. head of Femur ; 

 II. fill, ilio-femoral ; Is. fin. ischio-femoral ; .V. Neck ; 

 p.i.f. Pubiscliio - femoral muscle; 6b. Obturator 

 muscle insertion. 



