54 
PRIMROSE : THE ANATOMY OF THE ORANG OUTANG 
from the anterior iliac margin, and similarly Hepburn^ describes it as 
blended with the gluteus minimus. On the other hand Macalister- 
describes it as uniting with the gluteus medius (not minimus) in the 
Gorilla. Concerning the occurrence of the muscle among the lower 
apes, Huxley^ tells us that in Cynopithecinae the scansorius is found, 
but that it is sometimes blended with the gluteus minimus. Bischoff,^ 
whilst he states that it fails in the lower apes generally, mentions that 
it is represented by a weak bundle in Cynocephalus, Cercopithecus and 
Macacus. 
Thus we find that the scansorius is best developed as a separate 
muscle in the Orang and the Chimpanzee among anthropoid apes, and 
in all other apes it varies very considerably in its development, and is 
usually blended with the gluteus minimus or the gluteus medius, com- 
monly the former. 
The scansorius would thus appear to have more or less intimate connec- 
tion with the gluteus medius and minimus. Fick combats the suggestion 
of Henke that it is developed from the iliacus, on the ground that the 
sartorius muscle intervenes between these two muscles ; in my specimen 
I not only found the sartorius intervening but also the rectus. Bischoff, 
too, refers to the rectus intervening between the ilio-psoas, and what he 
believes to be the representative of the scansorius in the Gibbon. 
The function of the scansorius muscle was demonstrated by Owen,® 
who called it the “ Invertor femoris,” holding that it was a powerful 
rotator of the thigh and could have very little effect in drawing the thigh 
up. He states regarding the muscle ‘‘ that it appears rather to have 
reference to that structure in the hip joint which, in the Orang especially, 
from the absence of the ligamentum teres, and in the Chimpanzee, from 
the yielding texture of that ligament, permits a greater extent of inward 
rotation than can be accomplished in man.” Fick® questions the 
appropriateness of calling this muscle the climbing muscle. Flexion of 
the femur which is carried out to a limited extent by the scansorius, is a 
movement performed in climbing, but there are many other more 
powerful flexors of the femur. Then the scansorius rotates the thigh 
inwards in a forcible manner, and this is apparently its chief action. 
The ape, however, does not appear to rotate the thigh inwards in 
1 Loc. cit., p. 325. 
2 Loc. cit., p. 504. 
3 Loc. cit., Vol. 11 , p. 40. 
4 Loc. cit. I, p. 224. 
5 Loc. cit., p. 68. 
6 Loc. cit. I, p. 36. 
