102 Veterinary Elements. 



the capillaries, the portal vein, however, fetches blood 

 from the stomach and intestines to the liver. The arte- 

 ries, it was mentioned, kept dividing and subdividing 

 until the capillaries were reached, the veins do just the 

 opposite in that they keep uniting until a large vein 

 (vena cava) is formed, which empties into the right side 

 of the heart. The jugular vein in the furrow of the 

 neck is the one from which blood is usually drawn in 

 cattle and horses. 



The Lymphatic System. This system consists of ves- 

 sels and nodes (glands), the latter term nodes being sub- 

 stituted for glands, owing to the fact that these nodes do 

 not secrete, hence it would be wrong to term them 

 glands. The system might be compared to a line of 

 railway with the nodes as the stopping places. The nodes 

 are bean-shaped and can be readily found in the animal 

 after death, e. g., between the lungs, on the inside of the 

 limbs, thighs and in the folds of the mesentery, when if 

 cut in halves the outer part is seen to be lighter -in color 

 than the inner, they resemble a very small kidney in 

 fact; from these nodes are sent out leucocytes (white 

 blood cells); the spleen or milt may be considered as a 

 modified lymphatic node. The vessels originate as very 

 small channels in the spaces between the cells of the 

 body, especially those of the serous membranes. 

 Lymphatic vessels are found in all parts of the body, 

 those in the limbs possess valves; these vessels unite and 

 gradually form larger vessels, until the thoracic duct is 

 formed, which runs along underneath the back bone and 

 empties into the vena cava. The lymphatic nodes are 

 markedly affected in many diseases, such as tuberculosis, 

 etc. 



