FUSION OF HAXDS. 481 



intL'inal condyle on the front of the hiuueriH ami perhaps also into the bone above 

 it. '- One /rtV/eps- sufficiently developed, with its three heads, and inserted into the 

 perfect nlna. A second /r/'ce^As, however, exists which is quite imperfectly developed; 



one head arises from just below the head of the humerus and a second 



from the lower part of the humerus. It is in-ierted into thi imperfect olecranon 

 l)Ut sends a tendon to the corresponding inner condyle, and receives a large slip from 

 the other ^r/ce^j.s; in structure it is muscular at each extremity and tendinous 

 midway. A supernumerary slip of muscles," appears through the capsule of the 

 shoulder joint, like the long head of another hicejjs, "passes under the tendon of the 

 2>ectoraHs major and is inserted into the" extra internal condyle. "There was nf) well 

 defined brachiaJis anfiai)<." 



"In the forearm the imifcles usually connected with the radius and thuml) are 

 of course wanting. The superficial flexor of the fingers arises from the inner condyle 

 corresponding to the ^lerfect ulna; and sends a tendon to each finger, excepting the 

 little finger of the imperfect side" [/. e. of the extra hand] "also a slip from the 

 tendon of the inde.x finger to the deep-seated tendon of the .same." The deep flexor 

 arises in two parts. Th:it for the normal liand arises chiefly from the normal ulna, 

 partly from the interosseous membrane. Tiie portion for the index has its muscular 

 belly to a gr-eat extent separate from the rest. The part for the extra fingers arises 

 almost if not quite exclusively from tlie inverted ulna. The little finger has only a 

 small slip given off from the side of the tendon to the ring finger. ^'Flexor car])! 

 vlnaris well developed on the perfect side, but on the other indistinct." This indis- 

 tinctness probably applies to the muscular belly, for the tendon is perfectly plain, 

 and about as large as the normal one. Each goes to the pisiform bone and prol)ably 

 further. The second one seems to arise froui the fibrous or muscular expansion at 

 the outer side of the forearm near the inverted olecranon. No mention is made of a 

 palmaris /oikjus but a prominence in the cast indicates that it existed. "Pronator 

 quadratus quite well marked, and also the interossei .''' There is a slip of muscle or 

 fascia, now dried and shrunken, running from tlie muscular mass })clow the internal 

 condyle to the inverted ulna just below the elbow, strongly suggesting a rudimentary 

 2^ronator radii teres. 



The system of the extensors is very complicated, and owing to the distortion of 

 the dried muscles, not easy to make out perfectly. Still a good deal can be added 

 to the original description. No e.ctensores carpi uJnares are found, nor is there any 

 mention of them. The}' probably existed, howe\'er, as the groove for the tendon is 

 slightly marked at the lower end of each ulna. A muscle, which may represent one 

 of them, runs along the outer border of the forearm. It springs from a muscular mass 

 on the free edge of tlie inverteil ulna and is inserted apparent!}' into the outer side of its 



MEMiiIliS HOSTON SdC. NAT. HINT., Vm.. IV. lil 



