240 
Fig. 60. 
Skull of a Rodent, 
Hind leg, Antelope. 
fluences their dexterity, and gives variety to 
their modes of action: it is the faculty of 
opposing a thumb to the other fingers, so as 
to seize the smallest objects, which constitutes 
a hand, properly so called. This faculty is 
carried to its highest degree of perfection in 
man, in whom the whole anterior extremity is 
free, and can be exclusively employed in pre- 
hension. These different combinations, which 
strictly determine the nature of the several mam- 
miferous animals, have formed the grounds for 
their distribution into the following Orders. 
“ Amongst the Unguiculate animals, the 
first is Man, who, in addition to his peculiar 
privileges in every other respect, is distinguished 
zoologically by possessing hands on the ante- 
rior extremities alone ; the posterior extremities 
being destined to sustain him in the erect 
position. ( Fig. 60.) 
“The Order which comes nearest to Man, 
—that termed Quadrumana,—has hands on the 
four extremities. ( Fig. 61.) 
“ Another Order, termed Carnivora, has not 
the thumb free and opposable on either the 
anterior or posterior extremities. ( Fig. 62.) 
“ These three Orders likewise seve- 
rally the three kinds of teeth, viz. molars, lani- 
aries, and incisors. 
“ The quadrupeds of the fourth Order, viz. 
the Rodentia, have the digits differing little from 
those of the Carnivora; but they want the 
laniary teeth, and have the incisors of a form 
and Supedtion altogether peculiar to them- 
selves. ( Fig. 63.) 
«“ To these succeed the animals whose digits 
now become much cramped, being sunk deep 
in large and, most commonly, crooked claws. 
They are further defective in the absence of 
MAMMALIA. 
Fig. 61. 
if w 
Hind extremity, Ape. 
Fig. 64. 
Shall of the Giraffe. 
incisor teeth; some of them even want th 
laniaries, and others are altogether destitute o 
dentary organs. We shall com he 
under the term Edentata. (See fig. 33, vol. ii 
. 49.) - 
Pe This distribution of unguiculate 
would be perfect, and would form a 4 
lar chain, if New Holland had not latel 
furnished us with a small collateral chai 
composed of the Marsupial animals, all th 
genera of which, while they are connected by 
a general similarity of organization, at the sal 
time correspond in their dentition* and die’ 
some to the Carnivora, others to the Rodenti 
and a third tribe to the Edentata. “al 
“ The Ungulate animals are less numerou 
and present fewer variations of form. 
“ The Ruminantia, by their cloven feet 
(Fg 64,) their want of upper incisors, (fig. 65. 
and their complicated stomach, form a ver: 
distinct Order. ae 
“ All the other quadrupeds with hoofs migl 
be united into a single Order, which I woul 
call Pachydermata or Jumenta, (fig. 66,) th 
elephant excepted, which might form an Orde 
of itself, having some remote affinities to t 
Order Rodentia. The Pachyderms have com: 
monly incisors in the upper as well as the low 
jaw.  ( Fig. 67.) ‘a 
“ Last of all come the Mammalia whic 
have no hinder extremities, and whose fish-liki 
form and aquatic life would induce us to form 
them into a separate Class, if their economy 
* In the article MARSUPIALTIA it will be shown how 
much more essential are the points of resemblance 
between the dentition of the different Marsupié 
animals than between any of these and the pla 
cental genera, with which they correspond in iet 
