

386 



LYMPHATIC SYSTEM. 



glands, as already said, with a dense investment of connective tissue. The arterial 

 branches go in part directly to the glandular substance, but partly run along the 

 trabeculas. The former end in the glandular capillary network above-mentioned, 

 from which the veins begin, and tend to the hilum alongside the arteries. The 

 branches which run along the trabeculse are partly conducted to the coat of the 

 gland to be there distributed ; but most of their branches pass to the glandular 

 substance, the connective tissue of the trabeculas which ensheaths them passing 

 gradually into the lymphoid tissue of the pulp, so that this at first appears as a 



Fig. 445. SECTION OF THE MEDULLARY SUBSTANCE OP A LYMPHATIC GLAND (ox). 300 DIAMETERS. 



(Recklinghausen. ) 

 a, a, a, follicular or lymphoid cords ; b, b, trabecula3 ; c, lymph-sinus ; d, d, blood-vessels. 



sheath to the arterial branch (as in the spleen). The latter soon, however, breaks 

 up into capillaries which ramify in the gland-pulp, supported by its pervading 

 retiform tissue, which forms an additional adventitious coat around the minute vessels. 

 As to the lymphatics of the gland, the afferent vessels, after branching out upon 

 and in the tissue of the capsule, send their branches through it to open into the 

 lymph-sinuses of the cortex, and the efferent lymphatics begin by fine branches 

 leading from the lymph-sinuses of the medullary part, and forming at the hilum a 

 dense plexus of tortuous and varicose-looking vessels, from which branches proceed 

 to join the larger efferent trunks. The lymph-sinus, therefore, forms a path for the 

 passage of the lymph, interposed between the afferent and efferent lymphatics, 

 communicating with both and maintaining the continuity of the lymph-stream. 

 The afferent and efferent vessels, where they open into the lymph-sinus, lay aside 

 all their coats, except the epithelial lining, which is continued over the trabeculas 

 and the interior of the capsule. 



The chief differences of structure which are seen in lymphatic glands depend 

 upon the relative amount and nature of the framework. Thus whereas in some 

 animals both the capsule and the trabeculse are strong and muscular, in others they 

 are less developed and contain but little plain muscular tissue. In some animals 



