MINUTE ANATOMY OF THE LYMPHATIC FOLLICLES. 327 



THE RETICULUM, first demonstrated by Billroth, consists of 

 very fine fibrils varying in their thickness, which for the most 

 part pursue a straight course, and form a close network, the 

 meshes of which are only sufficiently large to contain a few 

 lymph corpuscles in each. The fibrils when fresh are extra- 

 ordinarily pale, present a homogeneous appearance, and are 

 distinguished from elastic fibres, to which, after the hardening 

 of the gland, they present some similarity, by their lustre, and 

 especially also by their chemical characters ; acetic acid and 

 soda making them swell up so strongly that they can no longer 

 be perceived. The nodal points of this plexus are usually very 

 small, and exhibit nuclei, but whether these are simply adhe- 

 rent to or are contained within peculiar cells occupying the 

 interior of the substance of the fibrils remains to be ascertained. 

 The lymph corpuscle-like cells, which constitute by far the 

 greatest part of the follicular tissue, become isolated with extra- 

 ordinary facility. They are contained in the milky fluid which 

 flows when sections are made, and differ in some respects, and 

 especially in their size, from one another (see lymph). The 

 fibrils of the reticulum, situated at the periphery of the follicle, 

 are in direct connection with the intercellular substance of the 

 surrounding connective tissue ; they attach themselves also to 

 the bloodvessels, and especially to the capillaries, which tra- 

 verse the follicle in the form of a wide-meshed plexus. The 

 vessels are thus supported by a framework of fibrils, and hang 

 freely in the spaces of the meshes. 



The relations of the lymphatic vessels are of special interest. 

 It has been a subject of dispute whether the follicles are rich 

 or poor in lymphatics; the presence of lymphatic vessels in the 

 follicles has even been altogether denied, and the conclusion 

 drawn that the follicles are of no special importance in the 

 lymphatic system. It is true that lymphatic vessels are not 

 present in the interior of each individual follicle ; for even the 

 most complete injection of the lymphatic vessels of the intestinal 

 canal, as was pointed out by Teichmann, leaves the interior 

 of the follicles free, whilst Frey's injections of the tonsils 

 have shown that here also, however, abundantly lymphatics are 

 distributed through the whole organ, none are present in the 

 individual follicles. These injections have, however, shown 



