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HANDBOOK OF PHYSIOLOGY. 



in the course of the lymphatic vessels, and through which the chief part 

 of the lymph passes in its course to be discharged into the blood-vessels. 

 They are found in great numbers in the mesentery, and along the great 

 vessels of the abdomen, thorax, and neck; in the axilla and groin; a 



Fig. 281 Section of a mesenteric gland from the ox, slightly magnified, a, Hilus ; b (in the 

 central part of the figure), medullary substance ; c, cortical substance with indistinct alveoli ; d, 

 capsule. (Kolliker.) 



few in the popliteal space^ but not further down the leg, and in the 

 arm as far as the elbow. Some lymphatics do not, however, pass through 

 glands before entering the thoracic duct. 



Structure. A lymphatic gland is covered externally by a capsule of 

 connective tissue, generally containing some unstriped muscle. At the 

 inner side of the gland, which is somewhat concave (hilus), (fig. 281, a), 



Fig. 882 Section of medullary substance of an inguinal gland of an ox. a, a, glandular sub 



the capsule sends inward processes called trabeculce in which the blood- 

 vessels are contained, and these join with other processes prolonged from 

 the inner surface of the part of the capsule covering the convex or outer 

 part of the gland; they have a structure similar to that of the capsule, 

 and entering the gland from all sides, and freely communicating, form 



