CROUPOUS INFLAMMATION. 423 



epiglottidean folds — we notice circumscribed spots of a milk- 

 white colour, on an intensely hypera3mic base. The white spot 

 soon rises to a height of half a line at most above the level of 

 the mucous surface, and the false membrane is complete. On 

 attempting to pick it off with a blunt instrument, we find this to 

 be impracticable during its earlier stage ; if we use violence, we 

 lacerate the surface and cause bleeding. At a later period, 

 the membrane separates of its own accord ; its edges are first of 

 all loosened by a moderate degree of suppuration, and the 

 entire patch is then liberated from its base. The circumscribed 

 catarrli which persists for a time upon the denuded base (often 

 erroneously called an "ulcer"), ceases spontaneously; if not 

 meddled with, it leaves neither loss of substance nor scar. A 

 secondary extension of the false membranes is very rare ; they 

 are never known to recur on the same patch, unless previously 

 stripped off before their spontaneous maturation. 



§ 365. These striking and important peculiarities are satis- 

 factorily explained by microscopical examination. We learn 

 from this, to our astonishment, that the false membranes do not 

 consist of fibrin. If little shreds of a false membrane are 

 soaked in a weak ammoniacal solution of carmine, then washed 

 and teazed out with needles, we may readily assure ourselves 

 that the naked-eye appearance of coagulated fibrin is produced 

 by cells, and nothing but cells, which have undergone a peculiar 

 degeneration of their proto])lasm, and an equally peculiar fusion 

 with one another. But for the reddish dots which indicate the 

 nuclei, we might fairly doubt the corpuscular nature of these 

 angular, lustrous, firmly united flakes. As it is, however, we 

 must consent to the hypothesis of some metamorphosis of the 

 corpuscular elements, concerning whose place in general patho- 

 logy we can at present only guess. The external appearances 

 may be aptly rendered by the term " glassy swelling," employed 

 by Weber to denote amyloid infiltration. It seems certain that 

 the cells contain more solid matter than do normal cells ; now if 

 tliis excess of solid matter were fibrin, we might speak of a 

 ^^ fibrinous degeneration" ; inasmuch, however, as we are quite 

 ignorant of its nature, the term "fibrinous degeneration" can 

 only be applied to the naked-eye appearances ; even with this 

 limitation, it would involve a tacit assumption which it is better, 

 in my opinion, to avoid. 



