208 



OF ABSORPTION AND SANGUIFICATION. 



through the former than the latter. The course which the lymph takes in 

 traversing these somewhat lacuuar spaces around the medullary substance 

 contained within the alveoli, is termed by Frey the superficial lymph-path. 

 The central or medullary portion consists of a close network or reticulum 

 of connective-tissue fibres, a, Fig. 87 ; in the interstices of which are nu- 



FIG. 85. 



FIG. 87. 



FIG. 85. Section of Lymphatic Gland, showing, a, a, the fibrous tissue winch forms its exterior ; b, b, 

 superficial vasa iufereutia ; e, o, larger alveoli, near the surface ; d, d, smaller alveoli of the interior ; 

 e, e, fibrous walls of the alveoli. 



FIG. 86. Simple Lymphatic Gland, a, the capsule, with sections of lymphatics, d, d, coursing through 

 it. b, hicunar and intercommunicating passages, permeated by the lymph, and forming tin- superficial 

 lymph-path of Frey. c, nucleus or medullary portion of the gland, in the centre of which the section 

 of a bloodvessel may be seen. The path pursued by the lymph through the medullary portion consti- 

 tutes the deep or secondary lymph-path of Frey. 



FIG. 87. Portion of the Medullary substance of the Mesenteric Gland of an ox. The artery injected 

 with Chromate of Lead X 300. a. medullary substance with capillary network, fine reticulum of con- 

 nective tissue, and a few lymph-corpuscles; b, b, superficial lymph-path, traversed by a reticulum of 

 nucleated cells (c, c) with numerous anastomosing prolongations. The lymph-corpuscles have for the 

 most part been removed with a camel-hair brush ; <!, d, trabeculte, composed almost exclusively of un- 

 striped muscular tissue; g, a small medullary cord or bridge, containing a bloodvessel and numerous 

 lymph-corpuscles. 



merous lymph-corpuscles. It is not bounded by any definite membrane, 

 though a kind of investing wall is formed by the connective-tissue fibres 

 being much more closely arranged near the surface; fluids, therefore, which 

 are circulating through the superficial lymph-path (b), Figs. 87 and 88, may 

 also slowly percolate through the medullary portion, and this constitutes the 

 deep lymph-path of Frey. The medullary portion is freely supplied with 

 bloodvessels. It thus appears that the lymph or chyle entering one of the 

 niescntci'ic glands passes, under ordinary circumstances, from the afferent 

 to the efferent vessels, through the superficial lymph-path, that is, chiefly 

 through the investing follicular spaces around and between the alveoli ; 



