THE LIMBS. 315 



part of the capsule are continuous and form parts of the capsule 

 of the joint ; they come to occupy a position within the joint as 

 the femoral condyles grow backwards. 



/ "crucial ligaments ' 

 post. lig. 



Fig. 252. — Showing the Origin of the Crucial Ligaments of the Knee. 



In Eeptiles and in lower mammals the fibula enters into the 

 formation of the knee joint as the ulna does in that of the elbow. 

 This is at no time the condition in the human foetus (G-runbaum). 

 The external malleolus in primates is generally shorter than the 

 internal ; this is the case in man until the 3rd month of foetal 

 life ; after the 3rd month the external is the longer (Wilgress). 



