1879.] NATURAL SCIENCES OF PHILADELPHIA. 55 



pared with the same muscles in man. In the forearm the prona- 

 tor radii teres arose by two heads, the median nerve passing be- 

 tween them as in Man, whereas I found only one head in the 

 Gorilla. The palmaris longus was well developed: whereas it was 

 absent in the Gorilla I dissected. Flexor sublimis digitorum and 

 profundus were more split up than in Man, but as a whole there 

 was no marked difference between them and those of Man. The 

 flexor longus pollicis, joined to the perforator of the index, was 

 to a certain extent differentiated from the flexor profundus digi- 

 torum, its tendon passed between the two heads of the flexor 

 brevis pollicis. The other muscles of the thumb and those of the 

 little finger compared favorably with those of Man; the lumbri- 

 cales were large. The supinator longus arose from the humerus 

 much higher up than in Man. The extensor ossi metacarpi pol- 

 licis terminated in two tendons; the secundii internodii pollicis 

 was present, but there was no extensor primi-internodii. I found 

 this muscle, however, in the Gorilla. The extensor indicis and 

 extensor minimi digiti terminated in their respective digits singly, 

 whereas in the lower monkeys the middle finger is supplied by 

 a slip from the indicis, and the ring finger with one from the 

 minimi digiti in addition to the tendons of the extensor commu- 

 nis. According to some anatomists the extensor indicus in the 

 Chimpanzee supplies both index and middle fingers. The Chim- 

 panzee seems, from the above brief sketch of the muscular sys- 

 tem of the upper extremity, to be closer allied to Man than the 

 Gorilla, inasmuch as the pronator arises by two heads and in 

 having a palmaris longus and a flexor longus pollicis, but it differs 

 from the Gorilla and Man in that the extensor ossii metacarpi 

 divides into two tendons, and in there being no extensor primi in- 

 ternodii pollicis. 



Lower Extremity. Traill, 1 in his account of the Chimpanzee, 

 figures a muscle, which he called the scansorius, rising from the 

 ileum and inserted into the femur. This muscle appears to me to 

 be simply a part of the gluteus minimus. According to Vrolik 2 

 the tensor vaginae femoris had been confounded with the so-called 

 scansorius by Traill, but in my specimen the former muscle was 

 very well developed, and I should not have noticed any thing par- 

 ticular about the gluteus had not a portion of it been described 



' Traill, op. ciL, Plate I. Fig. 1. 

 2 Vrolik, op. cit., p. 21. 



