352 MR. R. OWEN ON THE OSTEOLOGY OF 
pressed from before backwards. An error which has crept into the excellent and labo- 
rious work on Comparative Anatomy which the lamented death of the celebrated 
Meckel has left unfinished, requires here to be noticed, as it attributes a community of 
structure to the two species of Orang in a part which affords one of the best-marked 
differences. The head of the femur, which presents a smooth unbroken surface in the 
Orang, is marked with the pit for the attachment of the ligamentum teres as well in the 
adult as in the young Chimpanzee, in which I have ascertained the existence of that 
ligament in a dissection of a recent specimen. Meckel describes the absence of the 
ligamentum teres in the Pongo as well as in the Orang, and this is the case ; but it is 
only another of the many coincidences of structure which prove the identity of the two 
animals. This peculiarity of the hip-joint appears. to relate to the disproportionate 
shortness of the legs in Stmia Satyrus; but the deterioration which they consequently 
suffer, as means of support, is compensated by the advantages which they gain as instru- 
ments of prehension, their extent and variety of motion being increased by the removal 
of a ligament that acts as an impediment to both in the animals which possess it. 
The tibia in the Chimpanzee is proportionally thicker at the upper end, and the 
fibula considerably stronger at the lower end, than in Man: the interosseous space 
is wider, and the anterior convexity of both bones may be perceived to be slightly 
increased. The patelle are proportionally smaller. 
The relative size and position of the tarsal bones more nearly correspond to the same 
in the human subject than is found in any other Quadrumanous animal; but the de- 
viations, though slight, are nevertheless indicative of the habit of turning the foot from 
the position necessary for supporting the body, to that which is best adapted for the 
readier application of the sole to the branches of trees for the purposes of climbing, viz. 
with the outer or fibular edge of the foot inclined to the ground ; such a position being 
evidently most in accordance with the natural connexions of the bones of the tarsus. 
The os calcis is relatively feeble as compared with that of Man, being more compressed 
from side to side, and smaller in all its dimensions; but it projects backwards to a 
greater proportional degree than in the Orang or inferior Simie. From the inclination 
of the tarsus to rest on its outer edge, the os naviculare is further developed downwards, 
so as to project considerably below the bones of the same row without inconvenience 
from pressure on the sole. The internal cuneiform bone has a corresponding inclination, 
and thus the Aalluz, or great toe or hind thumb, is attached to the tarsus in a position 
best adapted for its being applied as an opposable instrument to the other toes. The 
whole foot of the Chimpanzee is relatively narrower and longer than in Man; and the 
digital phalanges are more inflected towards the sole. The admeasurements in the Table 
show the relative length of the hinder thumb, and other parts of the foot in the Chim- 
panzee and Orang. 
The organization of the lower extremities evidently bespeaks a creature destined 
to reside in forests ; and the modifications of the bony structure, which add to the fa- 

