4.90 Zoological Society. 
gation of the short arm of the lever (which every bone represents) 
in proportion to the long arm of the same; or (otherwise expressed) 
on the extent of the distance between the fulcrum and weight in 
proportion to the distance between the fulcrum and the power. 
As respects the proportions of the fore-limbs, the Orang Utan 
approaches the Gibbons, and retrogresses from Man more than the 
Chimpanzee, since in the former the arms reach to the heel, in the 
latter to about the knee-joint. 
Section IV.—Or tue Hinp ExtTremItTIEs. 
The pelvis presents us with a type far degraded from the Bimanous. 
The hips are narrow; the iliac bones long and flat, and their superior 
margins do not present an arc of a circle, as in Man, and indeed to 
a certain extent in the Chimpanzee. ‘The ischiatic bones, instead of 
retreating far backward from the symphysis of the pubes, are nearly 
on a plane with the iliac wings; their inferior margins are not cir- 
cular, as in Man, but present three sides of a lengthened parallelo- 
gram. The symphysis of the pubic bones resembles that of Man 
more than does that of the young Chimpanzee. 
The bones of the lower extremities are characterized, as those of 
the pectoral limbs, by the slenderness of their form and the slightness 
of their elevations. 
The trochanters of the femur are small; the linea aspera absent. 
The ligamentum teres appears to have been present, thus agreeing 
with Man and all the Simiade, excepting the Orang Utan. 
The tibia and fibula have rather a larger interosseous space than 
in Man, consequent on the bowing of the fibula. This space is large 
in the Orang Utan (Owen, ubi supra). 
The relative proportions of the leg and fore-leg are similar to the 
human. 
Let me here introduce a remark made on this animal by Yarrell, 
viz. that both the upper and lower extremities are incapable of the 
same extension as in Man, owing to the strong facial expansion of 
the flexor tendons passing before the elbows and behind the knee- 
joints to be attached to the upper halves of their respective bones 
below these parts (Notes on Dissection of Active Gibbon, Zoological 
Journal, vol. v. p. 14). 
The foot is remarkable for the smallness of the os calcis, a character: 
common to the Orangs and the lower Monkeys, and which, giving 
less basal surface to the foot, indicates less power of supporting the 
frame in the erect posture. The hind-foot is formed for grasping 
the branches of trees and not for walking on the ground. ‘The meta- 
tarsal bones decrease in strength (as in the hand) from the first 
towards the little finger. The thumb is strongly formed, especially 
its metatarsal bone. The ungueal phalanges are wanting in the 
second and third finger, and the ungueal and penultimate in the little 
finger of the only hind extremity mounted on the skeleton. These 
defects in the hind-foot arise from the animal having been affected 
some time previous to her death with a morbid state of constitution 
(supposed to arise from confinement), which caused her to gnaw off 
