ANATOMICAL STEUCTUEE OF ANTHEOPOID APES. 179 



are powerful. The first inter-osseous muscle is lilie- 

 wise well developed and bicipital. There is a short 

 flexor and an abductor for the little toe. I have 

 not yet been able to assure myself of the existence 

 of an opponens for that toe. In the chimpanzee 

 the muscular system of the great and little toe 

 does not essentially differ from that which we 

 have described in the gorilla. The flexor trevis 

 digitorum forms the perforated tendons of the 

 second and third toes. The flexor longus digitorum 

 provides the fourth and fifth toes with perforated, 

 and the second and fifth toes with perforating, 

 tendons, while those which belong to the third 

 and fourth toes have their origin in the flexor 

 longus pollicis. As in the gorilla, the latter 

 muscle produces a fibrous investment for the tendons 

 of the flexor longus digitorum. In the orang tliere 

 is an abductor of the great toe, a very slightly 

 developed opponens, a short bicipital flexor, and an 

 adductor. One of the long flexors of the toes 

 appears to represent the flexor longus pollicis in 

 man. It provides the second and fifth toes with 

 perforating tendons, while those of the third and 

 fourth toes have their origin in the other flexor longus 

 digitorum. There is no long flexor tendon on the 

 great toe. The perforated tendons in this case 

 generally belong to the short flexor muscle. In 

 addition to the perforated tendons of the fourth toe, 

 there is the long flexor already described. 



In a gibbon's great toe I observed an abductor, 

 a short bicipital -flexor, and a slightly developed 

 opponens, to which a wide fan-shaped adductor is 



