LYMPHATIC FOLLICLES 



147 



Peyer's patches, in the tongue as the lingual tonsil, in the fauces 

 as the faucial tonsils, in the pharynx as the pharyngeal tonsil, in 

 the wall of the laryngeal cavity, in the spleen as the Malpighian 

 corpuscles, in the lymphatic glands as the peripheral lymphatic 

 follicles, and in the thymus, where we may consider the lobule of 

 the organ as being the structural equivalent of a lymphatic fol- 

 licle. 



The lymphatic follicle consists of a mass of lymphoid tissue, 

 usually of ovoid form, which is surrounded by or embedded in 



FlG. 146. A LYMPHATIC NODULE, SOLITARY FOLLICLE, FROM THE LARGE INTESTINE OF 



MAN. 



In the upper part of the figure the edge of the intestinal mucosa is shown ; it con- 

 tains many secreting tubules which have been cut in transverse or oblique section and 

 are lined by columnar epithelium and goblet cells. Photo, x 80. 



connective tissue. In those locations where it exists independ- 

 ently the follicle is completely surrounded by the connective 

 tissue in which it lies. In other places, as in the lymphatic glands, 



