LYMPHATIC GLANDS. 



385 



tissue (fig. 440 ; fig. 443, r), the fibres of which are for the most part covered 

 and concealed in the natural condition by ramified cells, and is filled with fluid 

 lymph, containing many lymph-corpuscles, which may be washed out from sections 

 of the gland, so as to show the sinus, while the firmer gland-pulp, which the sinus 

 surrounds, keeps its place. The proper glandular substance is also pervaded and 



Fig. 443. RETICULUM FROM THE MEDULLARY PART OF A LYMPHATIC GLAND. (E. A. S.) 



tr, end of a trabecula of fibrous tissue ; r, r, open reticulum of the lymph-path, continuous with the 

 fibrils of the trabecula ; >', r', denser reticulum of the medullary lymphoid cords. The cells of the tissue 

 are not represented, the figure being taken from a preparation in which only the connective tissue fibrils 

 and the reticulum are stained. 



supported by fine retiform tissue (figs. 443, r', 445, a), communicating with that of 

 the surrounding lymph-sinus, but marked off from it by somewhat closer reticula- 

 tion at their mutual boundary, not so close, however, as to prevent fluids, or even 



Fig. 444. END OF A FIBROUS TRABECULA 



FROM THE SAME PREPARATION, SHOWING 

 THE CONTINUITY OF THE CONNECTIVE 

 TISSUE FIBRILS WITH THE RETICULUM : 

 HIGHLY MAGNIFIED. (E. A. S. ) 



tr, trabecula ; r, reticulum. 



corpuscles, from passing from the 

 one to the other. The gland-pulp 

 is otherwise made up of densely 

 packed lymphoid cells, occupying 

 the interstices of its supporting 

 retiform tissue, and usually exhibit- 

 ing, especially at its peripheral parts, 

 abundant evidence of the process of division and multiplication by karyokinesis. 

 This lymphoid tissue is traversed by a network of capillary blood-vessels (fig.,445,^,^), 

 which run throughout the proper glandular pulp, both cortical and medullary, but do 

 not pass into the surrounding lymph-sinus. The lymphoid cells of the glandular 

 pulp are similar in their general appearance to white blood- or lymph-corpuscles, 

 except that their nucleus is relatively larger, and their protoplasm less in amount. 



The ramified cells which cover the retiform tissue of the lymph-sinus, often 

 contain a considerable number of pigment-granules, especially in the medulla of the 

 gland. The trabeculae themselves have a covering of flattened cells, which on the 

 side turned towards the lymph-channel are provided with processes to anastomose 

 with those covering the retiform tissue. The inner surface of the capsule is also 

 lined with flattened cells, which are continuous at the entrance and exit of the 

 lymphatics with the endothelium of those vessels. 



Arteries enter and veins leave the gland at the hilum, surrounded, in some 



