DISEASES OF CATTLE 117 



tary canal, are absorbed and carried into the blood by the lym- 

 phatics, and by the blood to the places where nutrition is required. 

 The blood takes from all parts of the body all that is useless and 

 no longer required, and carries it to the different organs where it 

 is eliminated from the body. It contains within itself all the ele- 

 ments which nourish the body. 



The blood may be considered a fluid holding in solution cer- 

 tain inorganic elements and having certain bodies suspended in it. 

 To facilitate description, the blood may be considered as being made 

 up of the corpuscles and the liquor sanguinis. The corpuscles 

 are of two kinds, the red and the white, the red being the most 

 numerous. The color of the blood is due to the coloring matter 

 in the red corpuscles. The red corpuscles are the oxygen carriers. 

 Both kinds are very minute bodies, which require the aid of the 

 microscope to recognize them. The liquor sanguinis is composed 

 of water containing in solution salts, albumen, and the elements 

 of fibrin. 



The lymphatics, or absorbents, are the vessels which carry 

 the lymph and chyle in the blood. They begin as capillaries in all 

 parts of the body, gradually uniting to form larger trunks. Placed 

 along the course of the lymphatic vessels are glands, and in some 

 situations these glands are collected into groups; for example, in 

 the groin, etc. These glands are often involved in inflammation 

 arising from the absorption of deleterious matter. 



Absorption is the function of the lymphatics. The liquor san- 

 guinis passes from the blood capillaries to supply nutrition to the 

 tissues. All excess of the liquor sanguinis that is not required is 

 absorbed by the lymphatic vessels and conveyed back to the blood 

 by the lymphatic ducts. The lymphatics which proceed from the 

 intestines convey the chyle into the blood during digestion. As a 

 rule, the lymphatic vessels follow the course of the veins. All of 

 the absorbent vessels convey their contents to the thoracic duct and 

 right great lymphatic vein, which empty into the anterior vena 

 cava, where the lymph and chyle mix with the venous blood, and 

 thus maintain the supply of nutritive elements in the blood. 



Pulse. As fully explained, the heart pumps the blood 

 throughout the arterial system. The arteries are always full and 

 each contraction of the ventricle pumps more blood into them, 

 which distends their elastic walls and sends a wave along them 

 which gradually becomes less perceptible as it nears the very small 

 arteries, and is lost before the capillaries are reached. This wave 

 constitutes the pulse. The sensation or impression given to the 

 finger when placed upon the artery shows the force exerted by the 

 heart and some important facts concerning the condition of the cir- 

 culation. In cattle the average number of pulsations in a minute 

 (in adults) is from 50 to 60. The pulse is faster than normal after 

 exercise, excitement, on hot days from pain, and as a result of full- 

 ness of the stomach. In old animals it is slower than in the young 

 and in males slightly slower than in females. In fevers and infla- 



