484 
EXTREMITIES OF LOWER ANIMALS. 
stances, we find tlie number of bones in tbe hand increased, 
but all of them enclosed in one envelope, so that the fingers 
are not separate. This is the case with many aquatic animals 
'od* 
Fig. 229 .—Skeleton of the Camel. 
vc, cervical vertebrae; vd, dorsal vertebrae ; vl, lumbar vertebrae ; vs. sacral vertebrae; 
vq , caudal vertebrae; s, scapula; h, humerus; cu, ulna; ca, carpus; me, meta¬ 
carpus ; ph, phalanges ; fe, femur; ro, patella; ti, tibia; ta, tarsus; mt, metatarsus. 
-—such as the Whale tribe among Mammals, Turtles among 
Reptiles, and Fishes in general,—in which the hand is made 
to serve as a fin or paddle. In most of these, the bones of 
the arm are very short; and the movements of the extremity 
are chiefly confined to the wrist-joint. 
645. The structure of the lower extremities has a very great 
analogy to that of the upper; and the principal differences to 
be remarked between them, are such as are necessary to give 
to the former more solidity at the expense of freedom of 
motion, and to make them organs of locomotion instead of 
organs of prehension. Here, too, we have a bony framework, 
for the purpose of connecting the limb itself with the spine ; 
and as the weight of the body is constantly thrown upon the 
