450 MUCOUS MEMBRANES. 



Now if we undertake a painstaking histological analysis, by 

 examining vertical sections through the affected parts of the 

 laryngeal and tracheal mucous membranes, and endeavour to 

 eliminate wliatever is decidedly non-tuberculous, we must begin 

 by refusing a specific character to any morbid change in the 

 closed follicles. The larynx proper, indeed, is not, strictly 

 speaking, furnished with closed follicles ; but they are plentiful 

 above the epiglottis, at the base of the tongue, on the isthmus 

 faucium and the upper part of the pharynx ; and tuberculous 

 ulceration of the larynx proper is very commonly associated 

 with ulcers due to scrofulous inflammation, proliferation and 

 disintegration of these pharyngeal follicles. Further, the 

 laryngeal and tracheal ulcerations which start from the orifices 

 of the mucous glands, are not to be considered tuberculous. I 

 have elsewhere explained more fully (§356) how chronic catarrh 

 of the mucous membrane ma}' give rise to dilatation and hyper- 

 trophy of the mucous glands. I will now proceed to describe 

 another way in which these organs may become involved in 

 chronic catarrhal alterations of mucous surfaces ; and this is one 

 which, hitherto at all events, I have only met with in this par- 

 ticular region and in this particular case. Accordingly I must 

 regard it provisionally, as peculiar to the laryngo-tracheal 

 mucous membrane, and more especially as a very important 

 factor in that aggregate of anatomical changes which we include 

 under the name of laryngeal phthisis. 



If w^e separate the cut edges of a trachea whose mucous 

 lining is in a state of chronic catarrhal inflammation, and wipe 

 awa}" the mucus from its surface, we may readily detect with 

 the naked eye, the orifices of the mucous glands. In the inter- 

 vals between the cartilages they are very closely set ; here too, 

 they are especially wdde ; on a level with the rings they are fewer 

 in number and more narrow ; here and there, indeed, they may 

 even be quite absent. Now if we squeeze the trachea gently 

 from below", these openings are seen to exude small quantities 

 of viscid mucus, which present a sharp outline and resemble 

 grey, translucent dewdrops. Should any one of these drops, on 

 more careful inspection, exhibit a narrow straw-coloured border, 

 this indicates that the ulceration in question has already begun. 

 For this yellowish border consists of pus, pus produced by the 

 subepithelial connective tissue of the follicular duct, and dis- 



