MEGATHERIUM. 141 
The animal I shall select for my present pur- 
pose is that most extraordinary fossil creature, the 
Megatherium, (see PL 5), an animal, in some parts 
of its organization, nearly allied to the Sloth, and, 
like the Sloth, presenting an apparent monstrosity 
of external form, accompanied by many strange 
peculiarities of internal structure, which have 
hitherto been but little understood. 
The Sloths have afforded a remarkable ex- 
ception to the conclusions which naturalists have 
usually drawn, from their study of the organic 
structure and mechanism of other animals. The 
adaptation of each part of the body of the Ele- 
phant, to produce extraordinary strength, and of 
every member of the Deer and Antelope to give 
agility and speed, are too obvious to have escaped 
the attention of any scientific observer; but, it 
has been the constant practice of naturalists, to 
follow Buffon in misrepresenting the Sloths, as 
the most imperfectly constructed among all the 
members of the animal kingdom, as creatures 
incapable of enjoyment, and formed only for 
misery. 
The Sloth does, indeed, afford the greatest 
deviations from the ordinary structure of living 
quadrupeds ; and these have been erroneously 
considered as imperfections in its organization, 
without any compensating advantage. I have 
elsewhere* attempted to show that these ano- 
* Linnean Transactions, Vol. XVII. Part I. 
