206 Elementary Principles of Agriculture 



279. *Horses Should Be Selected for the work they 

 are to do. Different kinds of work require different 

 kinds of horses. A horse is of no particular value except 

 for what he can do. To fulfil his mission he must travel. 

 If he can draw a buggy containing one or two persons 

 at the rate of ten miles an hour, he is valuable as a road- 

 ster. Another horse that can draw his share of a load 

 weighing upwards of a ton, even though he moves 

 slowly, performs an equal amount of actual work, and 

 is just as useful to his owner as is the roadster. Since all 

 horses are valuable because they travel, although at 

 various rates and under widely varying conditions, 

 it will be interesting to make a study of those parts 

 of the horse's body directly connected with his loco- 

 motion. 



280. Use of the Muscles. It is not difficult to under- 

 stand that, with the horse as with ourselves, all motion 

 is the result of the action of the muscles. About 40 per 

 cent of the weight of an ordinary horse is muscle. All 

 muscles concerned with locomotion are attached to 

 bones, and when they contract they cause the bones to 

 which they are fastened to move. The lower part of 

 a horse's legs are nearly all bone, but the muscles in 

 the body and upper part of the limbs are attached to 

 various parts of the bony construction by tendons, 

 and can thus produce a motion of the parts located 

 some distance away. When contracted, the muscles 

 we are discussing are about three-quarters as long as 

 when at rest. The amount of motion produced by the 

 action of the muscles of, say one of the horse's legs, 

 will depend upon the length of the muscles and the 



* Paragraphs 279 to 285 are taken by permission from a leaflet on " The 

 Horse," by Prof. F. R. Marshall, published by the Ohio State University. 



