300 SKELETON OF THE EABBIT 



symphysis, the hinder portion of which is 

 formed by the ischium : the line of union 

 between these two bones is visible only in 

 very young skeletons. 



D. The Hind-Limb. 



The hind-limb is much larger than the fore-limb, and like 

 this is divisible into four main portions. 



In the hind-limb the departure from the primitive condition 

 is much less marked than in the fore-Hmb. The whole limb 

 has rotated forwards through about a right angle, so that the 

 preaxial border is directed inwards, and the postaxial out- 

 wards ; the original dorsal surface being turned forwards, and 

 the ventral surface backwards. 



1. The thigh, like the arm, contains a single bone, the 

 femur. Certain sesamoid bones in connection with 

 the knee-joint may be considered with it. 



i. The femur is an elongated bone, consisting of 

 a cylindrical shaft and two enlarged ex- 

 tremities. 



The proximal end bears on its inner or 

 preaxial side the prominent rounded head, 

 which articulates with the acetabulum to 

 form the hip-joint. To the outer side of the 

 head, and forming the end of the bone, is a 

 large rough process, the great trochanter : 

 between this and the head, on the posterior 

 surface of the bone, is a deep pit, the trochan- 

 teric or digital fossa. 



On the inner or preaxial side of the bone, 

 immediately below the head, is a rough ridge, 

 the lesser trochanter ; opposite to which on 

 the outer or postaxial side is the prominent 

 third trochanter. 



The lower or distal end of the bone bears 

 two large condyles which articulate with the 

 tibia. These are separated from each other 



