510 Mv.Z .Woodi on Variations in Human Myology. [June 18, 



out of 34 females in 102 subjects — a proportion of 43 per cent. In 32 it 

 was in both arms, in 4 in the right, and in 7 in the left only. It seems to 

 be the first point of transition of a slip to the ring-finger. 



In the left arm of the male (No. 7), the extensor minimi digiti was 

 entirely wanting. It was, however, amply substituted by three tendons 

 from the common extensor. 



29. Extensor carpi ulnaris. — In 5 males and 1 female this muscle sent 

 forward a slip of its tendon to be attached to the extensor aponeui^osis of 

 the little finger. In 2 males and 1 female this occurred in both arms, and 

 in three males in the right arm only. In another male (No. 6) and a 

 female (No. 31), this slip was present, but reached only as far as the head 

 of the fifth metacarpal bone, into the upper border of which it was im- 

 planted. 



This curious homologue of the peroneus quinti of the leg has beeu 

 found by the author in 12 per cent, of subjects, — viz. in 10 out of 

 68 males (7 of which were in both arms, and 3 in the right only), and in 2 

 only out of 34 females (in 1 in both arms, and in the other in the left 

 only). Thus it is 2 j times as common in the male sex as in the female. 



30. Extensor ossis metacarpi pollicis. — In all the 36 subjects of the 

 Table, except I male and 2 females, this muscle was provided with two 

 or more tendons. In the 72 subjects of the Tables of the present and 

 last year it has been found to be the case in 49. In the male subject 

 (No. 5) the division extended to the formation, in both arms, of two dis- 

 tinct muscles, the inner one of which was inserted by a single tendon into 

 the base of the pollex metacarpal ; and the outer was provided with not 

 less than four tendons, three of which were also inserted into the same 

 bone, while the other gave part origin to the opponens pollicis. In this 

 subject the extensor primi internodii was present, and inserted, with the 

 secundi, into the extreme phalanx. In both arms of two males, and in the 

 right only of three more, there were three tendons to the muscle, of which, 

 in two instances, two were inserted into the metacarpal, and the third into 

 the trapezium, or gave part origin to the opponens or abductor pollicis 

 muscles. In one subject, one of the tendons was inserted into the meta- 

 carpal bone, trapezium, and opponens respectively ; and in another, into the 

 metacarpal, opponens, and abductor respectively. In one, the tendon of 

 the extensor primi internodii came also from this muscle. In both arms 

 of two females and in the left arm of a third, two of the tendons went 

 to the metacarpal bone, and the other to the trapezium and abductor, or 

 to the latter only. In the opposite arms of those subjects in which three 

 tendons were found on one side only, there were always two tendons — one 

 inserted into the miCtacarpal, and the other into the opponens and abductor 

 pollicis. 



In 24 subjects, viz. 9 males and 10 females on both sides, 1 male and 

 1 female in the right arm only, and 2 females and 1 male in the left only, 

 the tendons of the extensor ossis metacarpi pollicis were two in number. 



