316 



LYMPH AND LYMPHATIC GLANDS 



[CH. XXIIL 



lymphatic glands, which are the factories of these corpuscles. Lym- 

 phocytes also pass into the lymph-stream wherever lymphoid tissue 

 is found, as in the tonsils, thymus, Malpighian bodies of the spleen, 

 Peyer's patches, and the solitary glands of the intestine. The lymph 

 that leaves these tissues is richer in lymph-cells than that which 

 enters them. 



When lymph is collected from the thoracic duct after a meal 

 containing fat, it is found to be milky. This is due to the presence 

 in the lymph of minutely subdivided fat particles absorbed from the 

 interior of the alimentary canal. The lymph is then called chyle. 

 The fat particles constitute what used to be called the molecular basis 

 of chyle. If the abdomen is opened during the process of fat absorp- 

 tion, the lymphatics are seen as white lines, due to their containing 

 this milky fluid. They are consequently called lacteals. 



The structure and arrangement of the lymphatic vessels are given 

 in Chapter XIX., and we have now to study the structure of 



The Lymphatic Glands. 



Lymphatic glands are round or oval bodies varying in size from 

 a hemp-seed to a bean, interposed in the course of the lymphatic 



FIG. 273. Diagrammatic section of lymphatic gland, a.l., Afferent; e.l., efferent lymphatics; C, 

 cortical substance ; l.h., lymphoid tissue; Z.s., lymph -path; c., fibrous capsule sending in trabeculse 

 tr. into the substance of the gland. (Sharpey.) 



vessels, and through which the lymph passes in its course to be dis- 

 charged into the blood-vessels. They are found in great numbers in 



