GLANDS OF THE ORAL CAVITY. 31 



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 greyish, soft, very vascular membrane J — J'" thick ; and still 

 more externally, a dense, relatively 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'" length, O01 — 0'03'" 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 pa- 

 pillae frequently contain mul- ^^aaf' 

 tiple loops, and the networks 

 around the capsules are still 

 closer (fig. 182). The fibrous 

 investment, lastly, consists 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 sur- 

 face 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. 



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

 sac, k 60. 



