ON DESIGN OF ANI]V;AL BODIES. 207 



and indolent habits has the bone smooth, thin, and 

 light ; but that nature, solicitous for our safety, in 

 a manner which we could not anticipate, combines 

 with the powerful muscular frame a dense and 

 perfect texture of bone, where every spine and 

 tubercle is completely developed. And thus the 

 inert and mechanical provisions of the bone always 

 bear relation to the living muscular power of the 

 limb, and exercise is as necessary to the perfect 

 constitution and form of a bone as it is to the in- 

 crease of the muscular power. Jockeys speak 

 correctly enough when they use the term ^'hlood 

 and bo7ie" as distinguishing the breed or genealo- 

 gy of horses ; for blood is an allowable term for 

 the race, and bone is so far significant, that the 

 bone of a running horse is remarkably compact 

 compared witli the bone of a draught horse. The 

 reader can easily understand, that in the gallop 

 the horse must come on his fore legs with a shock 

 proportionate to the span ; and that in the horse, 

 as in man, the greater the muscular power the 

 denser and stronger is the bone. The bone not 

 being as a mere pillar, intended to bear a perpen- 

 dicular weight, we ought not to expect uniformity 

 in its shape. Each bone, according to its place, 

 bears up against the varying forces that are applied 

 to it. Consider two men wrestling together, and 

 then think how various the direction of the resist- 

 ances must be : now they are pulling, and the 

 bones are like ropes ; or again, they are writhing 

 and twisting, and the bones bear a force like the 



