116 AARD WOLF. 
the toes and carry the heel considerably elevated 
above the ground, have much longer legs than plan- 
tigrade animals, and are therefore especially fitted 
for leaping and running with great ease and rapi- 
dity. Accordingly, it will be observed that the 
horse, the stag, the antelope, the dog, and other 
animals remarkable for rapidity of course, partake 
strongly of this formation ; and even their degree of 
swiftness 1s accurately measured by the comparative 
elevation of the heel. Inattentive observers some- 
times misapprehend the nature of this peculiar con- 
formation of the extremities of digitigrade animals, 
and are apt to confound the hough with the ankle, 
and to mistake for the knee what is really the heel of 
the animal. Thus we have heard it said that, inthe 
hind legs of the horse, the knee was bent in a con- 
trary direction to that of man. This is by no means 
true: a little attention to the succession of the dif- 
ferent joints and articulations will show that what is 
called the cannon-bone in the horse, and other digi- 
tigrade animals, in reality corresponds to the instep 
in man, and that what is generally mistaken for the 
knee really represents the heel. 
‘In the particular case of the Profe/es the natural 
effect of the digitigrade formation is, in some degree, 
lessened by the peculiar structure of the fore legs, 
which, contrary to the general rule observable in 
most other animals, are considerably longer than the 
hind. In this respect, also, the Prote/es resembles 
