MEGATHERIUM. 14o 
I shall not here enter on the unsettled ques- 
tions as to the precise age of the deposits in 
which the Megatherium is found, or the causes 
by which it has been extirpated ; my object is to 
show that the apparent incongruities of all its 
parts, are in reality systems of wise and well 
contrived adaptation to a peculiar mode of life. 
I proceed therefore to consider, in the order in 
which they are described by Cuvier, the most 
important organs of the Megatherium, beginning 
with the head, and from thence advancing to the 
trunk and extremities. 
Head, 
The bones of the head (PI. 5, Fig. 1. a.) most 
nearly resemble those of a Sloth. The long and 
broad bone, (b,) descending the cheek from the 
zygomatic arch, connects it more nearly with the 
Ai than with any other animal : this extraordi- 
nary bone must have been auxiliary to the power 
of muscles, acting with more than usual advan- 
tage, in giving motion to the lower jaw (d). 
The anterior part of the muzzle (c) is so 
strong and substantial, and so perforated with 
holes for the passage of nerves and vessels, 
that we may be sure it supported some organ of 
considerable size : a long trunk was needless to 
an animal possessing so long a neck ; the organ 
was probably a snout, something like that of 
GEOL. L 
