542 Mr. J. Wood on Variaiions in Human Myology, j[May 23, 



hesitation in referring it to the same class, with a somewhat higher 

 origin, obtained by differentiation of the more vertical fibres of the 

 posterior tibial aponeurosis. It constitutes probably, however, a link 

 with the plantaris, similar to that which the muscle of the arm, which 

 he has called the flexor carpi radialis hrevis, in some specimens forms 

 with the palmaris longus. From this point of view, this abnormal 

 muscle in the leg has a similar relation to the tibialis posticus that 

 the incomplete muscle in the arm has to a complete flexor of the middle 

 metacarpal hone, its homologue ; and it occupies a like intermediate 

 relation to the soleus as the one in the arm does to the flexor sublimis. 

 "We shall find herein the most probable solution of some of the difii- 

 culties of the homologies of these post-tibial muscles. 



In addition to the foregoing subjects, the author has had the advan- 

 tage of descriptions and sketches of muscular abnormalities affecting 

 three subjects out of eight, from his friend and former assistant Mr. 

 Bellamy, demonstrator in anatomy at Charing Cross Hospital. In 

 one muscular male were found four abnormalities, viz. in the right 

 arm, a double palmaris longus. The irregular one was placed internal 

 to the other, with its muscular fibres commencing just above the mid- 

 dle of the arm, and continued down to the annular ligament, into which 

 and the palmar fascia it was inserted. In the same arm was found a 

 Avell-developed extensor carpi radialis intermedius, arising distinctly 

 between the longior and brevior by a fusiform belly, and inserted by a 

 long tendon into the posterior annular ligament, close to the sheath for 

 the outer extensors of the thumb. This the author looks upon as a 

 formation intermediate to complete development of an extensor carpi 

 radialis accessorius. A little further extension forwards and outwards 

 would have brought the insertion of this muscle into relation with the 

 origin of the abductor pollicis brevis and the base of the first meta- 

 carpal. 



On the left arm of the same subject was a development in the same 

 direction in the lower part of the arm. A separate muscle was formed 

 of those upper fibres of the extensor ossis metacarpi pollicis, which so 

 frequently give off a slip of tendon to the origin of the abductor 

 pollicis. The muscle arose from the radius and interosseous ligament, 

 quite distinctly from the extensor ossis metacarpi, and was provided with a 

 separate tendon, which, passing in the same sheath with that of the latter, 

 subdivided into two tendons, one to be inserted into the base of the 

 first metacarpal, and the other to join the outer fibres of origin of the 

 abductor pollicis brevis. 



If both the tendencies evinced in this interesting concurrence had 

 been combined in the same arm, the result might have been the pro- 

 duction of an entire extensor carpi o^adialis accessorius, like that described 

 by the author in former papers. In the left leg of the same subject 

 was found a large and well-marked specimen of the accessorius ad cat- 



