42 AMERICAN FARMER'S HORSE BOOK. 



unite with the lower extremities of the coffin-bone. This 

 tendon, together with the shuttle-bone, forms the extension 

 of the heel, and lies immediately upon the inner or sensible 

 frog. Hence, any injuries which the latter may sustain will 

 be likely to involve both this tendon and the soft shuttle- 

 bone. 



THE BLOOD-VESSELS. 



Blood is defined by Dunglison, in his Medical Dictionary, 

 to be "an animal fluid formed chiefly from the chyle, ac- 

 quiring important properties during respiration, entering 

 every organ through the circulation, distributing the nutri- 

 tive principle to every texture, and the source of every se- 

 cretion. The blood is white in many of the inferior animals, 

 and they have been called white-blooded to distinguish them 

 from red-blooded, which class includes animals, birds, reptiles, 

 and fishes. Human blood is composed of water, albumen, 

 fibrine, an animal coloring substance, a little fatty matter, 

 and the difierent salts, as chloride of potassium, phosphate 

 of lime, subcarbonate of soda, lime, magnesia, oxide of iron, 

 and lactate of soda, united with an animal coloring matter. 

 Arterial blood is of a florid red color ; venous blood of a 

 brownish red." 



The blood of the horse difiers but slightly from that of 

 the human being. The important functions which the vital 

 fluid discharges in the animal economy is sufficiently indi- 

 cated by the character and variety of its constituent ele- 

 ments, all of which are needed to repair the waste and 

 decay of the system, and which the blood is constantly car- 

 rying to every part. In studying the blood of the horse at 

 any particular season, we are studying his general condition ; 

 and to keep it pure is the secret of maintaining the animal 

 in health. 



Two principal components unite to form the blood. These 

 are the serum, which is the watery fluid, and the coagulum, 

 or clot. It is the latter which contains the little red corpus- 

 cles which give color to the blood. In quantity, it much 



