xr HIND-LIMB 503 



hiving a conical form, its dorsal surface being grooved 

 for the firmer attachment of the horny claw. 



The ends of the long bones in both limbs are separately 

 ossified as epiphyses (compare p. 497), which eventually unite 

 with the shaft of the bone in question. Small sesamoid 

 bones are situated on the under or palmar side of the joints 

 of the digits. 



The pelvic arch consists of two lateral halves or in- 

 nominate bones, the long axis of which is almost parallel 

 with that of the vertebral column (Fig. 130), and which 

 are firmly united anteriorly and internally with the trans- 

 verse processes of the sacral vertebrae by a rough surface, 

 while ventrally they are connected together by cartilage 

 at the pelvic symphysis. On the cuter surface of each 

 innominate bone, at about the middle of its length, is a 

 deeply concave cup, the acetabulum, for articulation with 

 the head of the femur : in it, in young rabbits, a 

 triradiate suture can be seen, marking the boundaries of 

 the three bones of which the innominate is composed 

 (p. 51). Of these, the antero-dorsal is the ilium, which is 

 connected with the sacrum. The postero-ventral por- 

 tion of the innominate is perforated by a large aperture 

 the obturator foramen, through which a nerve of that 

 name passes (p. 532), the bone above and behind it 

 being the ischium, and that below and in front of it the 

 pubis. Behind the obturator foramen the ischium has a 

 thickened posterior edge or tuberosity, and then curves 

 round and becomes continuous with the pubis, both 

 bones taking part in the symphysis. 



In young rabbits it will be noticed that the part of the 

 pubis " which enters the acetabulum consists of a small, 

 distinct epiphysis. 



The hind- limb has undergone rotation forwards (Fig. 130), 

 so as to be brought, like the fore-limb, into a plane parallel 

 with the median vertical plane of the body ; but the rotation 

 being forwards, and the bones of the shank not being crossed, 



