THE CAT 225 
ease with which it springs forward are due to the immense 
leverage given by the arrangementof bones forming the limbs 
_Knee 
Heel 
Fig. 128.—Hind limb of Cat. 
—especially the hind-limbs. 
The heel of the Cat is com- 
pletely raised from the ground, 
being the projection at the 
back of the leg as shown. ‘The 
knee is close up under the body, 
the thigh being enclosed in the 
skin enveloping the body. By 
this arrangement the long bones 
of the raised foot act as a third 
lever, and hence greatly increase 
the leaping power of the animal. 
Besides this the back-bone 1s 
extremely flexible and elastic, 
and when bent and then sud- 
denly released, adds considerably to the force propelling 
the animal forward. 
The Cat after taking one of its immense springs; can 
alight on the ground without the least jar or shock, the 
fore-limb being jointed and bent in 
such a way as to prevent this. SA oule CL er 
Blade 
The elbow is close under the body, 
the upper arm bone being buried 
in the body. When the animal 
alights on the ground, the elbow 
joint gradually yields to the impact, 
bringing the humerus and lower 
arm-bones closer together and so 
lessening the shock. The fore- 
limbs, moreover, have considerable 
freedom—there being no collar- 
bones, and the shoulder blade being 
loosely imbedded in the flesh. 
Lloow 
Fig. 129.—Fore limb of Cat. 
Vee 
