SOCIETY OF THE UNIVERSITY OF ABERDEEN. 151 



Peroneus brevis. 



As in man. Its tendon commenced on one side of the muscle 

 about 7j an inch from the external malleolus. 



Gastrocnemius. 



The inner head was slightly the larger of the two and extended 

 further down the leg, forming, in fact, the bulk of the muscle at the 

 level of its insertion. The fibres of the outer head become slightly 

 tendinous at their insertion. 



Plantaria. 



Hepburn found no plantaris in either of the four anthropoids 

 he dissected. Charnpneys found it in his chimpanzee. In fact, its 

 occurrence seems to be very variable even in the anthropoids. In 

 my case, however, the plantaris was fairly well differentiated. It 

 arose in common with the outer head of gastrocnemius and its belly 

 became tendinous at a distance of 2 inches from its origin. The 

 tendon was exceedingly fine and only ^th of an inch in width. It 

 ran along the under surface of the outer head of gastrocnemius in 

 a sort of fascial tunnel from which it was, however, readily separable. 

 It was inserted by an expanded tendon into the os calcis between the 

 insertion of gastrocnemius and the origin of the abductor hallucis. 



Soleus. 



This muscle arose entirely from the fibula and was muscular 

 right down to the os calcis. 



Tendo Achillis. 



The tendo achillis of human anatomy can hardly be said to exist 

 in the chimpanzee as the combined insertion of soleus and gastro- 

 cnemious was tendinous only for about ^th of an inch. The line of 

 insertion was very slightly oblique. 



Popliteus. 



This muscle had two origins : 

 1. By the usual round tendon. 

 '2. By fibres arising from the capsule round the external condyle. 



