THE GREAT THICK-SKINNED ANIMALS 179 



you yourself place your legs when you are leaping off a wall or a bank? 

 Do you keep them perfectly stiff' and straight, or do you bend them 

 at the ankle, the knee, and the hip? 



Why, the latter, of course. If you were to straighten them, and 

 alight upon the soles of your feet, you would jar your body most 

 dreadfully, and would very likely do yourself some very severe injury. 

 But, by bending your" limbs, the force of the blow which your feet 

 receive has first to travel in one direction to your ankles, then in 

 another to your knees, then back again to your hips, and, finally, 

 forwards and upwards towards the head, so that it is broken no less 

 than three times before it reaches your brain. If you cannot quite 

 understand this, just make the experiment for yourself by jumping off 

 a chair, and noticing in what attitude you alight upon the floor. 



Men and women, however, do not spend most of their lives in 

 jumping, and tread so quietly, as a rule, that the brain receives but a 

 very slight shock at each footstep. And so the human skeleton, when 

 at rest, is perfectly upright, but possesses the power of bending at the 

 joints when required. The horse, however, is very differently made, 

 for his body is much heavier, and his gallop is, in fact, nothing but a 

 succession of jumps, so to speak; and thus it is necessary that his 

 bones should be set, not upright upon each other, but at an angle, so 

 that the jar caused by each footstep may be broken before it can 

 travel to the brain. 



Once more, as the horse is a very strong animal, and can undergo 

 violent exertion for a very long time, his chest is broad and deep, so 

 that plenty of room may be provided for large and powerful lungs. 



Every care, therefore, has been taken by nature to make the 

 horse both a swift and a strong animal, and so it is well suited to be 

 the servant of man. But he has found that he has so much work of 

 different sorts to be done that it cannot be all performed by the same 

 kind of animals. He may want to ride for long distances at very great 

 speed, and so his horse must be formed something like a greyhound, 

 slight and active, and able easily to bear the weight of its rider. But, 

 then, he also wants his carriage to be drawn along the roads and his 

 plow through the fields, and this cannot be done by the same horse. 

 A race-horse is not heavy enough to plow, and a plow-horse is not 



