owing absolute anatomical differences:--

1. By the arrangement of the tarsal bones.

2. By having a short flexor and a short extensor muscle of the digits.

3. By possessing the muscle termed 'peronaeus longus'. And if we desire
to ascertain whether the terminal division of a limb, in other Primates,
is to be called a foot or a hand, it is by the presence or absence of
these characters that we must be guided, and not by the mere proportions
and greater or lesser mobility of the great toe, which may vary
indefinitely without any fundamental alteration in the structure of the
foot.

Keeping these considerations in mind, let us now turn to the limbs
of the Gorilla. The terminal division of the fore limb presents no
difficulty--bone for bone and muscle for muscle, are found to be
arranged essentially as in man, or with such minor differences as are
found as varieties in man. The Gorilla's hand is clumsier, heavier, and
has a thumb somewhat shorter in proportion than that of man; but no one
has ever doubted its being a true hand.

(FIGURE 19.--Foot of Man, Gorilla, and Orang-Utan of the same absolute
length, to show the differences in proportion of each. Letters as in
Figure 18. Reduced from original drawings by Mr. Waterhouse Hawkins.

At first sight, the termination of the hind limb of the Gorilla looks
very hand-like, and as it is still more so in many of the lower apes,
it is not wonderful that the appellation "Quadrumana," or four-handed
creatures, adopted from the older anatomists* by Blumenbach, and
unfortunately rendered current by Cuvier, should have gained such wide
acceptance as a name for the Simian group. ([Footnote] *In speaking of
the foot of his "Pygmie," Tyson remarks, p. 13:--"But this part in the
formation and in its function too, being liker a Hand than a Foot: for
the distinguishing this sort of animals from others, I have thought
whether it might not be reckoned and called rather Quadru-manus than
Quadrupes, 'i.e.' a four-handed rather than a four-footed animal." As
this passage was published in 1699, M. I. G. St. Hilaire is clearly in
error in ascribing the invention of the term "quadrumanous" to Buffon,
though "himanous" may belong to him. Tyson uses "Quadrumanus" in several
places, as at p. 91... "Our 'Pygmie' is no Man, nor yet the 'common
Ape', but a sort of 'Animal' between both; and though a 'Biped', yet of
the 'Quadrumanus'-kind: though some 'Men' too have been observed to
use their 'Feet