208 



LECTURE VIII. 



whether they were distinct formations or mere convolu- 

 tions of the lymphatic vessel protruding on the surface. 



Upon more delicate microscopical 

 examination, the proper (glandu- 

 lar) substance of the follicles can 

 easily be distinguished from the 

 fibrous meshwork (stroma) which 

 bounds them on all sides, and is 

 externally continuous with the 

 connective tissue of the capsule. 

 The internal substance is chiefly 

 composed of little cellular ele- 

 ments, which lie pretty loosely, 

 being merely enclosed in a fine 

 network of star-shaped, often nu- 

 cleated trabeculae. If we attempt to search for the 

 lymphatic vessels in the cortical substance, but very 

 little can be discovered of them in the stroma, and if a 

 gland be injected, the injection penetrates right into 

 the middle of the follicles. If a mesenteric gland be 

 examined during chylification, that is perhaps three or 

 four hours after a meal at which fat has been taken in 

 abundance, its whole substance appears white and per- 

 fectly milky, and on examining individual parts of it 

 microscopically, the minute fat-drops of the chyle may 

 be detected every where lying between the cellular ele- 

 ments of the follicles. It seems, therefore, that the cur- 

 rent of lymph forces its way between these elements, and 



Fig. 61. Sections through the cortical substance of human mesenteric glands. 

 A. View of the whole cortical substance slightly magnified : P, investing adipose 

 tissue and capsule, through which blood-vessels v, v, v enter. F, F, F. Follicles of 

 the gland, into which the blood-vessels in part plunge, at t, i the interstitial tissue 

 separating the follicles (stroma). 



B. More highly magnified (280 times). C. The tissue of the capsule with paral- 

 lel fibrils, a, a. The reticulum, partly empty, partly filled with the nucleated con- 

 tents. The whole corresponds to the outer part of a follicle. 



