44 



ZOOLOGY. 



which abound in the walls of these organs ; but the greater 

 part of the fibrin and fatty matters which form the chyle 

 follows another route, and penetrates another system of vessels, 

 by which it reaches the veins, but in an indirect way. These 

 vessels, called indifferently lacteals,^ or chyliferous vessels, 

 form a portion of the absorbent or lymphatic system of 

 vessels. (See 34.) They originate in the villosities of the 

 mucous membrane of the small intestine, and unite into 

 branches or single vessels, which are placed between the two 



Aorta. Thoracic Canal. Lymphatic Ganglions. 



{Kadicles of the 

 chyliferous 

 vessels. 

 Intestine. 



Lymphatic Vessels. Mesentery. 



Fig. 35. Chyliferous Vessels. 



folds of the mesentery. In their course towards the thoracic 

 duct, these lacteals pass through the ganglions called mesen- 

 teric (Fig. 35). Again assuming the form of single vessels 

 on emerging from these ganglions, they proceed to the thoracic 

 duct, in which they terminate. By means of this duct, the 



* From the milk-like appearance of the chyle which they contain. The 

 lacteals proceeding from the intestine to the lymphatic glands or ganglions 

 are called vasa afferentia, and those from the glands to the thoracic duct 

 Txisa ejferentia. 



