PHYSIOIiOGY, AND PATHOLOGY OF THE CHIMPANZEE. 351 



separate from the tendons. The insertions are as in Man. 

 Hepburn (24:) and Macalister (33) describe them as in Man. 

 Wilder (53), Dwight (18), and Ohampneys (11) state that the 

 tendon for the minimus arises from the profundus tendon to 

 the annularis. 



The supinator longios arises from the external supracondylar 

 ridge and from the shaft of the humerus as high up as the in- 

 sertion of the deltoid. Some fibres come fi'om the external 

 muscular septum, and some from the brachialis anticus. It has 

 a long tendon which is inserted into the shaft of the radius half 

 an inch above the styloid process. Some authors have recorded 

 slightly less or a little more extensive origin and insertion. This 

 animal agrees in this respect with Hepburn^s account (24). 



The extensor carpi radialis longior arises from the lower part 

 of the external supracondylar ridge and septum. Its tendon 

 separates very high up in the forearm, passes under the extensors 

 of the thumb, and is inserted into the radial side of the dorsal 

 aspect of the index metacarpal, and along the radial aspect of the 

 proximal half inch of the bone. This insertion is more extensive 

 than in some accounts. 



The extensor carpi radialis brevier arises from the lateral 

 epicondyle, the external lateral ligament of the elbow joint and 

 the fascia over the extensor communis digitorum. It is slightly 

 fused with the long extensor. It is inserted into the dorsal 

 aspect of the base of the third metacarpal by three small 

 tendons. 



The extensor communis digitorum arises from the external 

 epicondjde, the fascia over it, and the intermuscular septa on 

 either side. It remains fleshy to the posterior annular ligament. 

 The origin from the internal septum is particularly strong. It 

 is quite sepa,ra.te from the subjacent extensors. It separates into 

 three broad tendons to the index, medius, and annularis, and a 

 slender tendon goes to the minimus. Close to the heads of the 

 metacarpals there is strong lateral fusion between the tendons to 

 annularis and minimus. The tendons are inserted into the bases 

 of the ungual phalanges. Wilder (53), Vrolik (51), Moore (36), 

 and Macalister (33) deny the presence of a tendon to the minimus. 

 Dwight (18) and Ohampneys (11) say there is a slip between the 

 tendons to annularis and minimus. The tendons have very 

 powerful thickened expansions into the sides of the intei"- 

 phalangeal joints. 



The extensor 7ninimi digiti has a long, slender muscular belly 

 enclosed in a strong fascial tunnel. It arises from the fascia 

 over the anconeus, and from the common extensor origin from 

 the external epicondyle. A common dorsal expansion unites its 

 tendon to the innermost communis tendon over the head of the 

 fifth metacarpal. The expansion is veiy firmly adherent to 

 the capsule of the metacarpo-phalangeal joint. The insertion is 

 into the base of the ungual phalanx of the minimus. 



The extensor carpi ulnaris is as in Man. Several authors 

 describe this. 



