Comparative Mi/olog-y of the Chimpanzee. 3H1 



Abductor pollicis. A strong muscle, arising, so far as 

 I could see, upon the calcancum alone, and inserted as 

 in man with the internal head of the Flexor brevis, which 

 indeed is far more closely connected with it than with the 

 external head. From the small size and more outward 

 position of the calcaneum, and the divergence of the 

 great toe, this muscle would act rather as a direct flexor 

 and adductor than as an abductor. Vrolik says there was 

 a smaller fasciculus from the internal cuneiform, which 

 perhaps represented the internal head of the Flexor brevis, 

 of which he says there was but a single head. In the 

 Howling-Monkey the Abductor consisted of two parts, 

 the one from the calcaneum being the more distinct, and 

 acting as a flexor. 



Adductor pollicis obliquus. Corresponds to the single 

 muscle in man, but is very much larger and more nearly 

 transverse ; it arises as in man, and is inserted into the 

 first phalanx of the great toe, as in Vrolik's Chimpan- 

 zee and in Duvernoy's Gorilla and Orang. Traill makes 

 no division into two, but seems to include both this and 

 the Adductor transversus as one large muscle extending 

 nearly the whole length of the second metatarsal. The Ad- 

 ductor pollicis transversus appears to arise from the heads 

 of the second, third, and fourth metatarsals, and is thinner 

 than the preceding ; it is attached to all the bones of the 

 great toe from the head of the metatarsal inclusive, as in 

 Duvernoy's Gorilla and Orang. Vrolik says it came from 

 the fifth metatarsal. The Transversalis pedis is either 

 unmentioned or declared absent by all the authors, ex- 

 cepting perhaps Davernoy. There is none in this Chim- 

 panzee, unless the Adductor transversus represents it, as it 

 certainly does pretty nearly in position and action. 



Flexor brevis minimi digiti. Has its origin and inser- 

 tion as in man. The Abductor minimi digiti arises as in 

 man, but seems to consist of two not very distinct por- 



