12-2 



THE ESSENTIALS OF HISTOLOGY. 



one part of the gland there is usually a depression (hilum), and at the 

 bottom of this the medulla comes to the surface and its fibrous bands 

 are directly continuous with the capsule. 



The proper glandular substance (l.h) is composed of lymphoid tissue, 

 i.e. a fine reticulum with the meshes thickly occupied by lymph- 

 corpuscles. It occupies all the interstices of the gland, forming com- 

 paratively large rounded masses in the cortex (lymphoid nodules, C) 

 between the trabeculse, and smaller reticulating cord-like masses 

 (lymphoid cords, M) in the medulla. 



a.l. 



tr. 



FlG. 146. DIAGRAMMATIC SECTION OF LYMPHATIC GLAND. (Sharpey.) 



a. 1., afferent, e.L, efferent lymphatics ; C, cortical substance; M, reticulating cords of medullary 

 substance; l.s, lymph-sinus; c, fibrous coat sending trabeculse, tr, into the substance of 

 the gland. 



The cells which bridge across the lymph -channel in the medulla 

 (fig. 147, c) are branching nucleated cells which often contain pigment, 

 so that this part of the gland has a dark colour. The lymph-channel is 

 bridged across not only by these, but also by fibres derived from the 

 capsule and trabeculse, which pass to the lymphoid tissue and become 

 lost in its reticulum. But these fibres are often covered and concealed 

 by the branched cells. 



Lymphatic vessels (fig. 146, a.L) enter the lymph-channels after 

 passing through the capsule, and the lymph is conveyed slowly along 

 the channels of the cortical and medullary part towards the hilum, 

 taking up many lymph-corpuscles in its passage. At the hilum it is 



