50 ON THE ANATOMY OF THE 



moris is not so broad and fleshy ; the sartorius is 

 more slender ; the semi-membranosus is less mem- 

 branous, and the semi-ten dinosus ]ess tendinous than 

 the corresponding muscles in man. These two last 

 in the Orang approach nearly to the same muscles 

 in the Siinia Maimon. In the latter animal, they 

 descend lower on the anterior part of the tibia than 

 in the Orang, which, in this respect, is a medium 

 between man and the baboon. The gracilis has 

 nothing remarkable. The vasti muscles are much 

 weaker than in man, being thin and flat, especially 

 toward the patella. The triceps adductor femoris, 

 and biceps flexor cruris, resemble those parts in the 

 human subject ; but the muscles on the lower part 

 of the leg are considerably different, especially those 

 on its front, which overlap the upper part of the 

 tibia, so as to give the appearance of a convex shin- 

 bone. This is chiefly owing to the fulness of the 

 tibialis anticus ; the lower part of which is much 

 larger and more fleshy than in man, though less so 

 than in the Siinia Maimon. The peroneus longus 

 and brevis, are also rather more fleshy below in both 

 the simiae now under consideration, than in the hu- 

 man body. The gastrocnemius externus is flatter and 

 thinner, and its belly descends almost to the heel in 

 the Orang. The gastrocnemius internus descends 

 fleshy to the os calcis, giving the animal but little 

 appearance of a calf to the leg. We found no 

 plantaris, nor did we perceive a popliteus. The 

 extensor longus digitorum sends tendons to four of 



