10 
SYSTEM OF NATURE. 
tition.”—C. R. A. A second group, equivalent to the 
monkeys, is found in the lemurs; and I am unable to resist 
the conviction that a third group, always held to be one 
of great inferiority, occupies a place corresponding with 
that of the monkeys and lemurs. It will be seen that I 
allude to the sloths; and 1 am fully aware how much I 
hazard in venturing thus to break up the group known as 
Edentata, more especially since I purpose reducing it 
still further by the abstraction of the monotrematous mar¬ 
supials. 
Having proposed an alteration so important as the re¬ 
moval of the sloth from the Bruta to the Primates, I must 
explain my reasons for doing so. The face of the sloth is 
round, short, and remarkable for its almost human expres¬ 
sion, a character even more observable in this animal than 
in the majority of the monkeys. The structure of the skull 
and the teeth also exhibit some approaches to the monkeys, 
but none to the ant-eaters. The size, figure, and general 
external appearance is that of a monkey. The mammas 
are two only, and these are pectoral. The feet are always 
used as hands for grasping and climbing, and never as feet 
for walking or running on the ground. The sloth spends 
his time entirely in trees, among the branches of which 
he travels with wonderful rapidity. Having thus shown a 
series of approaches to the Primates, some of them per¬ 
haps rather superficial, but others really structural, I am 
willing to admit that there are other characters which seem 
to give the sloth a station in the system far below that of 
the monkeys. These are the inability to make progressive 
movement on the earth, the structure of the brain, and 
that of the arteries of the limbs. These must be exa¬ 
mined separately. 1st. The inability to walk or run on the 
