LYMPH GLANDS 



207 



and a lymphatic plexus over its surface. Such solitary nodules occur in 

 the mucous membranes of various organs. By contact with one another 

 laterally they constitute the noduli aggregati, or "Peyer's patches" of 

 the small intestine, which are macroscopic structures 1-5 cm. long. 

 Lymphoid nodules irregularly massed about epithelial pits become the 

 essential tissue of the tonsils. Wherever it occurs, lymphoid tissue has 

 essentially the same structure as that observed in the lymph glands. 



\ 



Sinus. 



Capsule. 1 *. 



Trabeculee. ' 



FIG. 196. LONGITUDINAL SECTION OF A HUMAN CERVICAL ^LYMPH GLAND. Xi2. 



Lymphoid tissue (formerly called adenoid tissue) consists of a frame- 

 work of reticular tissue (see Fig. 50, p. 61, and the accompanying de- 

 scription), together with detached cells, chiefly lymphocytes, which fill 

 its meshes. Eosinophiles and the various forms of blood corpuscles 

 brought in by the blood vessels, are present in small numbers. The lym- 

 phocytes are like those of the blood, and the lymph glands are centers for 

 their production. Stained with haematoxylin, lymphoid tissue, because 



