304 



VERTEBRATA. 



the metacarpus carry the digits, which also vary in number, 

 but are composed each of from two to three cylindrical bones, 

 which are known as the phalanges (p). 



Homologous parts are, as a rule, readily recognisable in the 

 hind-limb. The pelvic arch, by which the hind-limb is united 

 with the trunk, consists of three pieces the ilium, ischium, 

 and pubes which are usually anchylosed together, and form 

 conjointly what is known as the innominate bone (fig. 271, i). In 



y.... 



Fig. 270. Pectoral limb 

 (arm) of Chimpanzee. (After 

 Owen), c Clavicle ; 5 Scapula 

 or shoulder-blade; h Humerus; 

 r Radius; Ulna; d Bones of 

 the wrist, or carpus; m Meta- 

 carpus ; p Phalanges of the 

 fingers. 



Fig. 271. Hind-limb of the 

 Chimpanzee. i Innominate 

 bone ;f Thigh-bone or femur ; 

 t Tibia ; s Fibula ; r Bones of 

 the ankle, or tarsus ; m Meta- 

 tarsus ; p Phalanges. 



most Mammals, the two innominate bones unite in front by a 

 ligamentous or cartilaginous union, and they constitute, with 

 the sacrum, what is known as the pelvis. The hind-limb pro- 

 per consists of the following parts : i. The thigh-bone or 

 femur, corresponding with the humerus in the fore-limb. 2. 



