GLANDS OF THE ORAL CAVITY. 4G1 



gation 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 ; the apertures of the follicles frequently 

 unite, so as ultimately to form only a small number. Each section of 

 the tonsil, much as it may vary in the form of its cavity and its external 

 appearance, has exactly the same structure. Proceeding from the oral 

 cavity, we observe that its epithelium enters into the separate cavities of 

 the tonsil and, becoming somewhat thinner, completely lines all the 

 secondary cavities. Beneath it we find a grayish, soft, very vascular 

 membrane J J of a line thick ; and still more externally, a dense, rela- 

 tively thick fibrous covering, which, when two lobes or sections of the 

 tonsils are in contact, belongs to them in common, and is in contact at 

 their outer extremities with the common coat of the organ. The soft 

 thick layer between the epithelium and the fibrous investment has the 

 same composition as the corresponding layer of the follicular glands of 

 the root of the tongue. Here also we meet with conical or filiform, even 

 slightly branched papillae, of 0-06-0-08 of a line in length, 0-01-0-03 

 of a line in breadth, directed towards the epithelium ; internally to these, 

 round, completely closed follicles one close to the other, of the same size 

 and possessing the same contents as those previously described ; and 

 finally, a soft fibrous tissue connecting them, and containing numerous 

 vessels. The vessels are still more numerous than in the follicles of the 

 tongue, though their ramifications are essentially similar, except that 

 the papillae frequently contain multi- 

 ple loops, and the networks around FI?. 182. 

 the capsules are still closer (Fig. 182). 

 The fibrous investment, lastly, con- 

 sists of connective tissue, with elastic 

 fibres and receives certain muscular 

 fibres from the superior constrictor of 

 the pharynx. Nerves may be detected 

 on the external surface of the tonsil, 

 and in the papillae, but, as in the case 

 of the follicular glands of the root of 

 the tongue, I have failed to observe 

 them in the proper membrane of the follicles. 



Corresponding with their structural similarity is the resemblance in 

 the secretion of the tonsils and that of the lingual follicles, though the 

 former is not easily obtained pure on account of the tonsils also receiv- 

 ing the ducts of mucous glands. It is a grayish-white mucous substance, 

 which, however, so far as I have been able to observe, contains no mucus, 

 but is composed either of cast-off epithelial plates alone, or of a mixture 



Fia. 182. Vessels of a few follicles from a human tonsil, seen from the cavity of a sac, 

 and magnified 60 diameters. 



