LYMPHATIC GLAXDS. clxxxvii 



lately, accepted by most anatomists ; but recent researches have shown 

 that the structure of these bodies is more complex. The following account 

 is founded on the descriptions of His and Kolliker. 



A lymphatic gland is covered externally with a coat composed of con- 

 nective tissue, mixed in certain animals, with muscular fibre-cells. This 

 coat or capsule is complete, except at the part where it gives passage to the 

 efferent lymphatics and the larger blood-vessels ; and this part of the 

 gland, which often presents a depression or fissure, may be named the 

 hilus (fig. en. a). The proper sub- 

 stance of the gland consists of two 

 parts, the cortical, and within this 

 the medullary. The cortical part 

 occupies all the superficial part of 

 the gland, except the hilus, and in 

 the larger glands may attain a thick- 

 ness of from two to three lines. 

 The medullary portion occupies the 

 centre, and extends to the surface 

 at the hilus. It is best marked in 

 the inwardly seated glands, such as 

 the lumbar and meseuteric, whilst 

 in the subcutaneous glands it is more Fi ?; CII. -SECTION OF A MESENTERIC 



f GLAND FROM THE Ox, SLIGHTLY MAQNI- 



or less encroached upon by a core of FIED 



connective tissue, hilus-stroma (His), , ., 



' V /' a , hilus ; b, medullary substance; c, 



which enters with the larger blood- cortical substance with indistinct alveoli ; 

 vessels at the hilus, and surrounds d, capsule (alter Kolliker). 

 them together with the lymph-ves- 

 sels, in the centre of the gland, so that the medullary part is reduced to 

 a layer of no great thickness bounding inwardly the cortical part. 



Throughout both its cortical and medullary part the gland is pervaded by 

 a trabecular frame-work which incloses and supports the proper glandular 

 substance. The trabeculse pass inwards from the capsule. They consist, 

 in the ox, chiefly of plain muscular tissue ; in man, of connective tissue, 

 sparingly intermixed with muscular fibre-cells. In the cortical part they 

 are mostly lamellar in form, and divide the space into small compartments, 

 alveoli, from ^L- to -^ of an inch wide, which communicate laterally 

 with each other through openings in the imperfect partitions between them 

 (fig. cm. A). On reaching the medullary part the trabeculse take the form 

 of flattened bands or cords, and by their conjunction and reticulation form 

 a freely intercommunicating mesh work throughout the interior. (In the 

 figures they are represented mostly as cut across.) In these alveoles and 

 meshes is included the proper glandular substance, which appears as a tole- 

 rably firm pulp, or parenchyma. In the alveoli of the cortical part this 

 forms rounded nodules (fig. cm. AC?); in the trabecular meshes of the 

 medullary part it takes the shape of rounded cords joining in a corre- 

 sponding network (figs. cm. B d ; civ. a a) ; and, as the containing meshes 

 communicate, so the contained gland -pulp is continuous throughout. But 

 both in the cortical alveoles and the medullary trabecular meshes, a narrow 

 space (left white in the figs. cm. I ; civ., cv. 6) is left all round the gland- 

 pulp, between it and the alveolar partitions and trabecular bands, like what 

 would be left had the pulp shrunk away from the inside of a mould in which 

 it had been cast. This space is both a receptacle and a channel of pas- 

 sage for the lymph that goes through the gland ; it is the lymph-sinus 



