TUBERCULOSIS. 445 



serous membranes, the liver, and the kidneys, are precisely 

 analogous to the changes in the intestinal mucous membrane. 

 The alterations in the fibres of voluntary muscle {Zenker) will be 

 fullv described hereafter (§ 756). 



2. Tuberculosis. 



§ 383. Before beginning the study of tubercidosis as it 

 occurs in mucous membranes, we must learn to discriminate 

 carefully between tuberculous disease of mucous membranes, and 

 those diseases of the mucous membranes which occur in tuber- 

 culous patients. It is only in a few instances that the develop- 

 ment and decay of tubercles constitute the sum-total of the 

 morbid changes ; in a somewhat larger proportion of cases, they 

 form the leadino- feature of the disease : as a general rule 

 however, the actual growth of tubercles occupies a relatively 

 subordinate position, in comparison with the non- tubercular 

 alterations, serving as a sort of excitant or guiding impulse — as 

 a standing Avitness to the specific and incurable nature of the 

 malady. 



§ 384. Tuberculosis of i'he uro-genital mucous mem- 

 brane affords the best example of the changes which tuberculosis 

 per se is capable of effecting — of the disturbances which may be 

 ascribed exclusively to it. The tuberculous ulcer of the lu'inary 

 bladder is a shari^ly-circumscribed, more or less circular defect 

 in tlie mucous membrane, with a dirty -yellow, "bacony"' infil- 

 tration of its base and edges. On closer examination, this bacony 

 infiltration proves to consist of ^^true" tubercles; miliary 

 nodules, some grey, some cheesy, packed closely together, form 

 the floor and edxres of the ulcer, while i\\Q vouno^est and smallest 

 granulations serve to extend the process, and are scattered, far 

 in advance of the rest, through the healthy parenchyma of the 

 mucous membrane. In fact, the growth of miliary tubercles 

 takes the place of the " plastic infiltration'' of common inflam- 

 mation ; while their cheesy metamorphosis, softening, and dis- 

 integration, stand for the subsequent destructive suppuration. 

 Side by side with the older and mature ulcers, we usually find 

 the first beginnings of the disorder in the form of solitary, grey 

 or cheesy, miliary nodules, disseminated through the most super- 

 ficial laver of the connective tissue of the mucosa ; others 



