30 SPECIAL HISTOLOGY. 



present a whitish colour, and closely resemble the capsules 

 of Peyer's patches, the solitary glands, the vesicles of the spleen 

 and of the lymphatic glands. They consist of a tolerably solid 

 coat, about 0-002 — '003'" thick, composed of more homogeneous 

 connective tissue, without elastic fibres, and of greyish white 

 contents, which, when the follicle is pricked, exude in the form 

 of a drop, which becomes diffused through water, and consists 

 of a fluid with formed particles. The former, alkaline in its 

 reaction, is present in excessively small quantity, so that it 

 appears to be merely the connecting medium of the latter, 

 which consist of cells of 0003 — 0-005'" and free nuclei of 

 0*002 — 0-0025'" without any determinate character. Acetic 

 acid renders the cells granular, and thence communicates a 

 whitish tinge to the contents j but it precipitates no mucus, 

 the fluid differing decidedly in this respect from the ordinary 

 mucous secretion and agreeing with that of the splenic 

 corpuscles. The position of the follicles is usually such, that 

 they form a connected, almost simple layer, between the exter- 

 nal coat and the epithelium of the follicular glands, yet there 

 are localities, at least in animals, where two follicles are found 

 behind one another, or at greater intervals. 



The vessels of the follicular glands are very numerous, and 

 may often be traced naturally injected, in man. Small arteries 

 enter from without, passing through the fibrous coat to the 

 interior, ramify between the follicles, as they ascend, in an 

 elegant arborescent manner, and terminate in the papillae and 

 on the follicles. The vessels of the former present the same re- 

 lations as those of the other simple papillae, and are either simple 

 or complex loops ; around the follicles they form an exceedingly 

 elegant and abundant network, whose finest vessels, 0*004 — 

 0*006'" in diameter, take a wavy course, forming a moderately 

 close network immediately upon the membrane of the follicle. 

 The efferent veins converge from these two localities, and are 

 wide and numerous. Lymphatic vessels also, according to E. H. 

 Weber (Meckel's Archiv, 1827, p. 282), appear to proceed from 

 these glands, and I have myself noticed nerves upon them. 



The tonsils are, according to my investigations, nothing but 

 an aggregation of a certain number (10 to 20) of compound 

 follicular glands, which, intimately united and held together 

 by a common investment, form a large hemispherical organ • 



