MEGATHERIUM. lo3 
instrument to be employed continually in digging- 
food out of the ground ; 2°. this act of perpetual 
digging in search of stationary objects like roots, 
required but little locomotive power; 3°. the com- 
paratively small support afforded to the weight 
of the body by the fore-leg, was compensated 
by the extraordinary and colossal strength of 
the haunches and hind-legs. In the Elephant, 
the great weight of the head and tusks require 
shortness of neck, and imusual enlargement and 
strength in the fore-legs ; hence, the anterior 
parts of this animal are much stronger and larger 
than its hinder parts. In the case of the Mega- 
therium, the relative proportions are reversed ; 
the head is comparatively small, the neck is 
long, and the anterior part of the body but 
slightly loaded in comparison with its abdominal 
and posterior regions. In the shoulder blade 
and collar bone there is great provision to give 
strength and motion to the fore-legs ; but this 
motion is not progressive, nor is the strength 
calculated merely to support the weight of the 
body. The humerus, (k) articulates with the 
scapula by a round head, admitting of free 
motion in various directions, and is small at its 
upper and middle part, but at its lower end 
attains extraordinary breadth, in consequence 
of an enormous expansion of the crests, which 
rise from the condyles, to give origin to 
muscles for the movement of the fore-foot and 
