LYMPHATIC GLANDS. 



383 



a'hempseed, and others as large as an almond or a kidney bean, or even larger than 

 this. In shape, too, they present differences, but most of them are round or oval. 



The lymphatics or lacteals which enter a gland are named inferent or afferent 

 vessels (vasa inferentia seu affei'mtia), and those which issue from it efferent vessels 



O..L, 



tr. 



Fig. 440. DIAGRAMMATIC SECTION OF LYMPHATIC GLAND. (Sharpey. ) 



a.l, afferent ; e.l, efferent lymphatics. C, cortical substance. M, reticulating cords of medullary 

 substance, l.s, lymph-sinus ; c, fibrous coat sending trabeculse, tr, into the substance of the gland. 



(vasa efferentia}. The afferent vessels (fig. 440, a.T), on approaching a gland, 

 divide into many small branches, which enter the gland ; the efferent vessels 

 commonly leave the gland in the form of small branches, and at a little distance 



Fig. 441. SECTION OF A MESENTERIC GLAND PROM THE ox, 



SLIGHTLY MAGNIFIED. (Kblliker. ) 



a, hilum ; b, medullary substance ; c, cortical substance 

 with indistinct alveoli ; d, capsule. 



beyond it, or sometimes even before issuing 

 from it, unite into one or more trunks (e. I), 

 usually larger in size but fewer in number than 

 those of the afferent vessels. 



A lymphatic gland is covered externally with 

 a coat (figs. 440, 442, c) composed of connective 



tissue, mixed, in certain animals, with muscular fibre-cells. This coat or capsule 

 dips into the interior of the gland at the place where the larger blood-vessels 

 and the efferent lymphatics pass into and out of the organ ; and this part of 

 the gland, which often has a depression or fissure, is named the hilum (fig. 441, a). 

 The proper substance of the gland consists of two parts, the cortical (fig. 440, (7), 

 and within this the medullary (J/). The cortex occupies all the superficial part of 

 the gland, except the hilum, and in the larger glands may attain a thickness of one 

 or two millimeters. The medullary portion occupies the centre and extends to the 

 surface at the hilum. It is most developed in the inwardly-seated glands, such as 

 the lumbar and mesenteric, whilst in the subcutaneous glands it is more encroached 



