504 Mr. J. Wood on Variations in Human Myology. [June 18^ 



and 1 in the left only. In 1 male and 1 female only was the flexor carpi 

 radialis hrevis present when this muscle was absent or rudimentary. In 

 the left arm of one female a substitutory slip came from the flexor suhlimis 

 digitorum. In 3 males, in 2 on both sides, and 1 on the left only, such a 

 slip was derived from the flexor carpi radialis. 



24. Extensor carpi radialis longior. — In 2 males and 1 female, twice in 

 the right, and once in the left arm, this muscle was entirely blended at its 

 origin with its twin muscle the brevior. In the male (No. 1 1) the coal- 

 esced muscle gave off two tendons, which had the usual insertions of the 

 longior and brevior. In No. 2 it gave off three tendons, the middle one 

 being that of the muscle called by the author the extensor intermediuSy 

 which was inserted with the brevior. In the female (No. 32) there arose 

 in the left arm, from the combined muscular belly, no less than four ten- 

 dons, of which the inner, corresponding to that of the brevior^ was the 

 largest and subdivided into two (making five in all), the superficial one 

 of which was inserted into the bases of the second and third metacarpals, 

 and the deeper into that of the third only. The outermost tendon, repre- 

 senting the longior^ was inserted into the base of the second metacarpal ; 

 while the two intermediate tendons united at the lower end of the radius, 

 to be inserted together, on the inner side of the longior^ into the base of the 

 mc?ea7-metacarpal. This coalescence of the fleshy bellies of the longior and 

 brevior has been alluded to as an absence of the extensor brevior^ with the 

 longior supplying two tendons, by Meckel (Muskellehre, S. 509), quoting 

 Albinus (Hist. Muse. p. 446), and Salzmann, and also by Macwhinnie and 

 Henle. Theile mentions it as a union of the longior and brevior (op. cit. 

 p. 226). Meckel remarks upon its resemblance to the arrangement in the 

 lower animals, and after him Macwhinnie and Henle. The construction 

 in the female (No. 32) somewhat resembles the formation in the Rumi- 

 nants ; that in the male (No. 2) finds its counterpart in the Hyaena and 

 Brown Bear. In the right arm of No. 7, and the left of No. 12, the ten- 

 don of the longior was split into two, both having the normal insertion. 



In the female (No. 21) the longior gave off a large muscular slip to join 

 the supinator longus high up. This resembles the doubleheaded supinator 

 longus found by Mivart in the Iguana tuberculata, the second head of 

 which arose with the extensor carpi radialis (Proc. Zool. Soc. June 1867, 

 p. 783). 



Extensor carpi radialis accessorius. — The above-described doubling of 

 the tendon of the longior forms, apparently, the first point of transition to 

 the abnormahty found in no less than seven subjects (viz. Nos. 4, 6, 10, 15, 

 & 17, males, and Nos. 27 & 29, females). In these a slip from the outer 

 side of the tendon of the longior had a detached insertion into the base of 

 the pollex-metaearpal and into the fl7'st dorsal interosseous muscle. Such 

 slips have this session been very closely looked for as intermediate transi- 

 tional forms of the muscle which has been described and figured by the 

 author in former papers as the extensor accessorius. In the male (No. 4) 



