CATABKll. 415 



comes to exhibit throughout, a brown, yellow, grey, or even 

 black hue ; the distribution of the pigment following the law 

 which has just been set forth ; it is only in rare and very severe 

 cases that it is more uniformly distributed, so that the stomacli, 

 for instance, looks as if it had been flooded with ink. 



§ 354. A series of peculiar phenomena is due to the possi- 

 bility of serous transudation from mucous membranes lined with 

 laminated pavement-epithelium. The outermost, compact layer 

 of cells, resists the passage of the serum for a time ; it is 

 stripped from its bed, and so forms vesicles or bullae Accord- 

 ingly, in catarrhal affections of the buccal cavity, we not unfre- 

 quently see the mucous membrane of the lips, gums, tongue and 

 cheeks studded with transparent, watery blebs, some as large as 

 a pea, while the majority are no bigger than a millet-seed ; in 

 about tw^enty-four hours' time they burst and discharge their 

 serous contents. Here the matter may end ; or the raised por- 

 tion of epithelium may become altogether detached, leaving a 

 small, circular defect, an excoriation, behind. The denuded 

 patch of mucous membrane proceeds to secrete pus ; its epitlielial 

 border becomes sodden, and appears to the naked eye as a sharp, 

 w^hite margin ; the entire patch is surrounded by a hyperasmic 

 areola, and the circumscribed purulent catarrh lasts until the 

 cessation of the general catarrhal state. These " ulcers " may 

 increase considerably in size ; the greater part of the buccal 

 surface may thus come to be quite raw, wdiile the smaller })art 

 continues normal (scurvy, putrid stomatitis). 



Analogous conditions are met with in all the atrial chambers 

 of the mucous tract (see § 348). We are most familiar v,'ith 

 those about the os uteri externum and the glans penis. 



§ 355. Complete and incomplete degeneration^ cJironic catarrh^ 

 and hyperplastic conditions of the mucous membranes. What has 

 been said above concerning catarrhal inflammation, refers to its 

 acute variety, which runs a definite course. After this is com- 

 pleted, the mucous membrane may return entirely to its normal 

 state. In this connexion, the behaviour of tlie parenchymatous 

 connective tissue of the mucous membrane is most important. 

 We have already seen (§ 352) how actively the subepithelial 

 connective tissue takes part in the catarrhal process. The fleshy 

 thickening of the catarrhal mucous membrane was due, i]i no 

 small measure, to an infiltration of the subepithelial connective 



