348 Prof. A. ]\Iacalister on the Myology of 



a displaced insertion : the two other palmar interossei are 

 normal. To the metacarpal bone of the pollex two small 

 muscles are attached, one on the ulnar and one on the radial 

 side, both springing from the second row of the carpus ; the 

 inner of these may either be an interosseus primus volaris or 

 a flexor; the outer is evidently the adductor*. The flexor 

 tendons in the Chimpanzee were not so conti-acted as those in 

 Wilder'.s Chimpanzee, and they permitted the perfect exten- 

 sion of the fingers. 



The muscles of the hinder limb were as follows : — Gluten* 

 maximus and tensor vaginae femoris forming one thin expan- 

 sion, quadrilateral in shape, but with the femoral side pro- 

 longed ; it equalled the gluteus medius in weight. Of all the 

 muscles in the body this is perhaps the least anthropoid in 

 appearance. Prof. Humphry found the tensor vaginee femoris 

 separate ; but AVilder found them continuous, and describes 

 the latter part as being larger than in man, while the lowest 

 portion was also thick and strong. All agree in having seen 

 this muscle extend along the entire of the back of the femur. 

 It was not in our specimen continuous with the popliteus or 

 external gastrocnemius, as found by Prof. Humphry. The 

 gluteus medius, though wide, was only half the weight of the 

 gluteus minimus, instead of being the largest of the three 

 glutei, as it was in Dr. Wilder's Chimpanzee (/. c. p. 369) ; 

 the latter muscle did not arise from the coccyx — a point about 

 which Dr. Wilder was not certain. The gluteus quartus or 

 scansorius was one-fifth the size of the gluteus medius ; it has 

 been found by Traill, Wilder, and Wyman, but was not found 

 in Prof. Humphry's specimens. The pyriformis was perfectly 

 separate ; the gemelli were joined to the internal obturator, 

 which was to the external obturator in the proportion of 6 to 5 ; 

 the quadratus femoris was also present, and about half the 

 size of the external obturator. 



The psoas pai-vus was present on both sides, and was one- 

 thirteenth the size of the psoadiliac muscle ; it was not found 

 by Vrolik, Wilder, or Wyman. The psoas magnus and 

 iliacus are inseparable, and the anterior crural nerve lies on 

 the inner side of both muscles. The pectineus was distinctly 

 bilaminar ; the three adductors also could be without any 

 laceration separated, and they were developed in the following 

 proportions : — pectineus, adductors longus and brevis nearly 

 equal ; adductor magnus nearly twice their combined weights. 



* In the forearm of this specimen of Ateles fuliginosvs I found a tendi- 

 nous slip passing from the middle of the tendon of the flexor carpi radialis 

 and running inwards to join the tendon of the palmaris longTis, just as the 

 last-named joined the apex of the palmar fascia. 



