86 THE LYMPHATIC SYSTEM. 



follicles is often less dense than that at the periphery. 

 Lymphatic glands may be regarded as highly specialized or 

 compound lymph-follicles. 



Fio. 38. 









Lymph-follicle (Flemming). 



Lymphoid tissue is widely distributed through the body. In 

 a diffuse form it is common in mucous membranes in many 

 situations, especially the alimentary canal. Circumscribed 

 lymph-follicles are most typically represented by the solitary 

 and agminate glands of the intestines ; also by the tonsils and 

 Malpighian corpuscles of the spleen. The lymphatic glands 

 and t hymns are also composed of lymphoid follicles. 



Lymphatic glands : Interposed in the course of the lymph- 

 atic vessels in many situations, notably in the mesenteries, 

 mediastina, and under the skin in certain parts, are numerous 

 lymphatic glands. These are oval or kidney-shaped bodies, 

 of small size, with a depression at one side, the hilum, where 

 the bloodvessels and efferent lymph-vessels enter and leave 

 the gland. 



The elements of lymphatic glands are sustentacular tissue, 



