OIDIUM ALBICANS. 191 



portion possesses a more or less soft cheese-like consistency, is 

 more or less thick, from the density of the finest paper to half a 

 line and more ; it adheres firmer at first than after a little while, 

 and finally peels off by itself, without injuring the continuity of 

 the mucous membrane. It is found alone or simultaneously on 

 the inner edge of the lips, where the mucous membrane begins, 

 on the inner side of the cheek, on the gums and the palate, on 

 the upper and lower surface of the tongue, in the throat, and in 

 the oesophagus, down as far as the cardia. Its microscopic con- 

 stituents and its cause are a peculiar fungus. (Berg.) 



Genus Oidium (Link) : Fila simplicia ramosa, minutissima, 

 pellucida, in floods aggregata, leviter intexta, articulata. Sporidia 

 ex articulis secedentibus orta, simplicia , pellucida. 



Species 47, Oidium albicans : Fila in cespitibus lam, primo 

 villosis, humidis, albis, dein sordide fulvis, vel fuscis, vel fusco- 

 fulvis intertexta, intus leviter granulosa, 0*004 lata, 0'050 

 0-600 mm. longa. Sporidia plerumque rotunda, aut vix ovalia, ex 

 articulis secedentibus orta } raro ovalia. 



Habitat : In membrana mucosa oris, faucium, cesophagi, narium, 

 in lacuminibus pharyngis senum, inter massas mucosas et epitheliosas 

 ad ligamenta aryepiglottid. ; in mucosa laryngis, in cicatricibus 

 bronchiorum, rarissime ad anum, labra, pudenda et mammas lac- 

 tantium. Pr&sertim in pueris, in adultis cachecticis, inprimis 

 sen Hi bus ad extremum vitae tempus. 



The white external layer consists, according to Berg, of the 

 condensed epithelium, in consequence of an enlargement of the 

 epithelial cells, of the elements of the fungus, and of molecular 

 protein- detritus. Reubold, however, states, that fibrinous cells, 

 the proper elements of pseudo- membranes, are wanting, and 

 that it contains only amorphous fibrin, exudation- cells, and, at 

 times, also globules of pus. The parasitical vegetation and the 

 epithelial enlargement extend at first only to the points of the 

 small papillae (at the tip of the tongue), and small white and 

 isolated patches are perceived (Muguet discret), which often 

 escape observation. If, however, fewer papilla are found on the 

 seat of the disease, and if the whole surface is smoother, as is 

 the case with the mucous membrane of the mouth, with the 

 exception of the upper part of the tongue, the external covering 

 appears in the shape of rings of ribands, which are intertwined, 

 and of hemispherical elevations produced by the fungus. The 

 more numerous these points and rings become, the more luxuriant 



