364 THE LYMPH-GLANDS. 



out of delicate elements of the reticular connective tissue intermixed with elastic 

 fibrils and arranged in a network (Fig. 131, C). In the meshes of this network, 

 lymph and lymph-cells are present in abundance. Upon the surface the tissue 

 becomes condensed into a somewhat more independent, conspicuous sheath, which, 

 however, is variously traversed by small spongy spaces in the reticular tissue. 

 Small lymphatics advance everywhere directly up to these lymph-follicles, often 

 keeping considerable areas of their surface covered with a rich network. Fre- 

 quently, also, the surface of the follicle is incorporated into the wall of the vessel, 

 at times throughout a slight, at other times throughout a considerable, extent, 

 so that the surface of the follicle is directly irrigated by the lymph of the vessel ; 

 and, if no direct canal-orifice of considerable size leads from the lumen of the 

 lymphatic into the interior of the spherical follicle, a communication must, never- 

 theless, be assumed to exist between the small lymphatic and the lymph-follicle, 

 and this is adequately provided by the innumerable spaces between the fol- 

 licles. Thus, the lymph-follicle is a true lymphatic structure, whose fluid and 

 lymph-cells can pass over into the stream of the adjacent lymphatics. The 

 follicles are provided, upon their surfaces, with a network of blood-vessels, 

 which also send numerous delicate ramifications and capillaries through the 

 interior of the follicle (A) , within which they are supported by the reticulum (B) . 

 It is to be inferred that leukocytes can pass from these capillaries into the follicle. 



It should be mentioned as of special importance in connection with 

 these follicles that, in the lymph-glands, the solitary as well as the 



FIG. 131. A, blood-vessels of the follicle; B, the reticulum and a branch of a blood-vessel; C, lymph-follicle 



with reticulum and sheath. 



conglobate glands, an enormous migration of the leukocytes normally 

 takes place uninterruptedly during life through the epithelium be- 

 tween the cells. The leukocytes insinuate themselves between the 

 epithelial cells, but, by their enormous migration, as well as by the 

 divisions that take place during this process, they impair the functions 

 of the epithelium and may even destroy it. Thus, in a measure, physio- 

 logical injuries result, which prepare the way for invading microorgan- 

 isms. The cells that have thus migrated later undergo disintegration. 



The compound lymph-glands (incorrectly designated lymph-glands) repre- 

 sent to a certain extent an aggregation of lymph-follicles of altered shape. Every 

 lymph-gland is surrounded externally by a connective-tissue capsule traversed 

 by numerous unstriated muscle-fibers, and from whose inner surface numerous 

 septa and bands (Fig. 132, a a) penetrate into the interior of the body of the gland, 

 and divide it into a large number of small compartments. The latter possess 

 within the cortical substance of the gland a rather rounded shape (alveoli), 

 in the medulla, a rather longitudinal sausage-shaped form (medullary spaces) . All, 

 however, are of the same significance and all are connected by communicating 

 orifices. Thus, a rich network of cavities, connected in all directions, is formed 

 within the lymph-gland by the septa. These spaces are traversed by the so- 



