1866.] Mr. J. Wood on Variations in Human Myology. 239 



This muscle lias been found in Birds, Bats, and Moles. The author has ' 

 also found it remarkably well-developed in the Giiineapig and some 

 others of the Rodentia. He believes it to be closely allied to the upward 

 extension of the pecf oralis minor, before alluded to, and to result from a 

 differentiation of such an upward extension. In the subject of the sketch 

 it was associated with a cleido-occipital (a), and with an increase in the 

 number of tendons to the little finger. 



In subject 26 was a curious muscular slip extending behind the axillary 

 vessels and nerves, from the insertion of the subscapular muscle to the 

 fascia covering the long head of the triceps, and derived from the tendon of 

 the latissimus dorsi. Apparently this is an imperfect form of development 

 of a short coraco-hrachialis muscle, such as that described in a former paper. 



In subject 13 was a high fascial origin of the abductor minimi digiti, 

 from the lower third of the forearm, like that described and figured in the 

 author's first series. This has been observed by Gilnther (Chirurgische 

 Muskellehre, Taf. xx. Fig. V. 18). 



A double abductor pollicis brevis was found in three cases, besides that 

 in which it was connected with a slip from the extensor carpi radialis acces- 

 sorius (given in fig. 4). In subject 23, and also in 32, was a double extensor 

 ossis metacarpi jpollicis, the tendon of one being inserted entirely into the 

 annular hgament and origin of the abductor pollicis. 



The rest of this column scarcely needs farther description. 



The six remaining columns are occupied by abnormalities of the muscles 

 of the leg, of which there are thirty-nine examples. 



22. Peroneus tertius. — Two out of five anomalies in this column result 

 from the total absence of this characteristically human muscle, giving a 

 very ape-like appearance to the foot. In No. 7 it vvas absent on the right 

 side only (see fig. 8), in No. 16 on both sides. In subjects 11 and 32 a 

 distinct tendinous slip from it was implanted into the base of the fourth 

 metatarsal. In another, the tendon was doubled, though both were in- 

 serted into the fifth metatarsal, spreading towards the fourth. 



23. Peroneus quinti. — In three out of five specimens found, this ten- 

 dinous slip from the peroneus brevis to the extensor aponeurosis of the 

 little toe was perfect, as described and figured in the last paper. In the 

 remaining two, the tendinous slip from the brevis, instead of reaching the 

 toe, became implanted upon the upper border of its metatarsal bone, near 

 the front end (fig. 8 a). In both cases this slip supplied the place of the 

 peroneus tertius, which was totally wanting, except in the left foot of 

 subject 7, in which both the slip and the muscle was present, though 

 small. In the subject of the figure the pe7'oneus brevis tendon gives also a 

 slip of origin to a bundle of muscular fibres which join the abductor minimi 

 digiti as a separate muscle {b) on the outer side. This is a somev/hat 

 similar arrangement to that of a specimen given in the author's first series, 

 in which t\iQ peroneus quinti was provided with a separate muscular belly 

 on the outer border of the foot. 



VOL. XV. X 



