THE CHIMPANZEE AND ORANG UTAN. 367 
patella is smaller in proportion than in Man, is of an oval shape, and has a single arti- 
cular surface without any ridge. 
The tarsus has the same number of bones ; and they have nearly the same forms as 
in the Chimpanzee, but admit of freer motion on each other, and constitute a relatively 
smaller proportion of the entire foot. The astragalus has its articular surface more 
oblique, and the foot in consequence is more turned inwards ; this bone is much flatter 
than in the human subject. The os calcis does not project so far backwards as in the 
Chimpanzee ; it is small and compressed. Lawrence aptly remarks, that “this single 
bone is, therefore, an infallible characteristic of Man ; and ‘ez calce hominem’ would 
probably be a safer rule than ‘ex pede Herculem’.”! The internal cuneiform bone 
recedes most from the human type in its greater production or development towards the 
plantar aspect, and in having the surface of articulation for the hallua, or great toe, 
below the range of the other articular surfaces. The metatarsal bones (that of the hallux 
excepted) are much longer, more concave towards the sole, and have greater inter- 
spaces than the human. The metatarsal bone of the second toe has its articulation with 
the tarsus on the same line as the rest: the metatarsal bone of the hallur extends very 
little beyond the middle of the preceding, and stands off from it at an acute angle. 
The peculiarity of the structure of the hinder thumb, viz. its having but one bone, and 
consequently no nail, was first observed by Camper?, who found it to be the case in seven 
out of eight Orangs which he had the opportunity of examining. In the Orang Utan de- 
cribed by M. Fred. Cuvier, however, it is expressly stated, “Tous les doigts des pieds 
avoient la méme structure que ceux de la main et étoient trés-libres dans leurs mouve- 
mens ; et tous, sans exception, avoient leurs ongles.”? In the individual dissected at 
the Museum of the Zoological Society, (October 1830,) the great toes had very perfect 
but small black nails, and also two phalanges in addition to the metatarsal bone: the 
same number of phalanges exists in the natural skeleton of Lord Amherst’s Orang pre- 
served in the Museum of the College of Surgeons, so that these exceptions much di- 
minish the importance of this circumstance as a generic or specific character‘. 
The phalanges of the other toes are remarkably elongated ; those of the first series 
are curved ; the middle toe exceeds the rest in length ; the concavity of the great toe 
is turned more towards the other toes than in the Chimpanzee: but the chief difference 
which obtains in the bony structure of the foot is in the relative length of the hind 
thumb. In the Orang it does not reach to the condyle of the adjoining metatarsal 
' Lectures, p. 144, * Giuvres, tom. i. p. 54. * Annales du Muséum, tom. xvi. p. 48. 
* Since, in addition to this, the intermaxillary sutures are obliterated at the development of the great cus- 
pidati, the generic character proposed by Dr. Leach for the Simia Satyrus will be unexceptionable in only 
one particular. 
“Prrnxcus. Os intermaxillaire parfaitement distinct ; point de ligament suspenseur de la ecuisse ; la derniere 
phalange du pouce du pied manque, et par consequent point d’ongle 4 ce pouce.”—Journal de Physique, 
tom, Ixxxix. p. 159. 
3¢c2 
