EDENTATA. 141 
Brapyrpus, Lin. 
The Sloths have cylindrical molars, and sharp canines longer than 
those molars, two mamme on the breast, and fingers united by the skin, 
and only marked externally by enormous compressed and crooked nails, 
which, when at rest, are always bent towards the palm of the hand, or 
the sole of the foot. The hind feet are obliquely articulated on the leg, 
and rest only upon their outer edge; the phalanges of the toes are 
articulated by a close ginglymus (qa), and the first, at a certain age, 
become soldered to the bones of the metacarpus or metatarsus, which 
also, in time, for want of use, experience the same fate. To this incon- 
venience in the organization of the extremities is added another, not less 
great, in their proportions. The arm and fore-arm are much longer than 
the thigh and leg, so that, when these animals walk, they are compelled to 
drag themselves along on their elbows. The pelvis is so large, and their 
thighs so much inclined to the sides, that they cannot approximate their 
knees. Their gait is the necessary effect of such a disproportioned 
structure.* They live on trees, and never remove from the one they are 
on until they have stripped it of every leaf, so painful to them is the 
requisite exertion to reach another. It is even asserted that to avoid the 
trouble of a regular descent, they let themselves fall from a branch. The 
female produces but a single young one at a birth, which she carries on 
her back. 
The viscera of these animals are not less singular than the rest of 
their conformation. The stomach is divided into four sacks, analogous 
to the four stomachs of the Ruminantia, but without leaflets or other 
internally salient parts, while the intestinal canal is short and without 
a caecum. 
M. Fr. Cuvier applies the name of Acuerus to those species that have 
three nails to the fore feet; they have a very short tail. 
Bradypus tridactylus, L.; Buff. XIII. v and vi. (The Ai)(d). A 
species in which sluggishness and all the details of the organiza- 
tion which produce it are carried to the highest degree. The thumb 
* M. Carlisle has observed that the arteries of the limbs commence by splitting 
into an infinitude of ramifications, which afterwards unite in one trunk, from which 
the usual branches proceed. This structure being met with in the Loris, whose gait 
is almost equally sluggish, it is possible that it may exert some influence on this 
slowness of motion. Independently of this, the Loris, the Ourang-Outang, the 
Coaita, all very slow animals, are remarkable for the length of their arms. 
(= (a) Ginglymus is a form of joint which resembles a hinge, and exists 
amongst animals under two forms. In the first one of the bones has a pulley like 
surface into which the other bone completing the joint is received. This is the 
state of the knee and elbow joints in the human body, and it has received the name 
of the angular ginglymus. The lateral or rotatory ginglymus is constituted by such 
a union as admits of the convex end or process of one bone in a hollow of another. 
—Ene. Ep. 
R&S (b) The name of Ai is given to the animal, because the plaintive sound 
which it emits is exactly imitated by pronouncing the vowels a and i. In falling 
from the branch, as is described above, this animal first rolls itself into a round ball; 
and, previously to its fall, it may be taken whilst it is attached to the branch, so 
great is its apathy._-Ene. Ep. 
