452 MUCOUS MEMBRANES. 



ready for expulsion, as soon as the abscess-cavity communicates 

 with the floor of the ulcer by an aperture large enough to allow 

 of its passage. (Arytsenoid cartilages.) As a general rule indeed, 

 this catastrophe is preceded hy a stage of true ulceration ; the 

 cartilage is laid bare, though only on one side, that which forms 

 the floor of the ulcer — while everywhere else the perichondrium 

 continues intimately united to its surface. The advance of the 

 destructive process may then be admirably traced in vertical 

 sections ; the outermost layers of cartilage -cells are transformed 

 by fusion into groups of pus-cells, while the cartilage-cavities 

 have simultaneously increased in size at the expense of the matrix 

 to such a degree, that just before they burst they are actually in 

 contact with one another. Hence the floor of the ulcer, so far 

 as it lies in the cartilage, is lined throughout with dilated car- 

 tilage-capsules full of pus. Meanwhile these alterations, though 

 very important, are confined within relatively narrow limits. 

 The third or fourth row of cartilage -cells (counting from the 

 floor of the ulcer) is quite intact ; at most, the nuclei may be 

 beginning to divide. In the trachea, the course of the ulcera- 

 tion may lead to the denudation of the majority of the rings on 

 their inner surface ; one ring after another becomes detached 

 from its extremities to its centre ; the separation extending in- 

 wards till it is complete, when the entire ring is coughed up. 



§ 390. Seeing that the most severe and extreme lesions of 

 the larynx and trachea may be produced by simple catarrhal 

 inflammation and ulceration, we may be tempted to inquire what 

 there is left for tuberculosis to accomplish ? Are tubercles pre- 

 sent at all in " laryngeal phthisis " ? and if present, what part do 

 they play ? It is quite clear that my own observations are op- 

 posed to any unconditional transfer of the results, arrived at by 

 studying tuberculosis of the urogenital mucous membrane, con- 

 cerning the mode of origin and extension of "tuberculous" ulcers, 

 to the mucous lining of the larjmx. On the contrary, I feel bound 

 to insist that the actual destruction in the latter case is operated, 

 not by the breaking- down of tubercular deposits, but by the 

 known resources of inflammatory proliferation. Nevertheless, I 

 am quite convinced, that here too, miliary tubercles may un- 

 doubtedly be developed ; grounding my belief partly on the 

 authority of Virchow, who has actually observed true " tuber- 

 culous " ulcers in the larynx, partly on certain appearances seen 



