OIDIUM ALBICANS. 197 



"V 



only luxuriating in the mucus of the mucous membrane. Lelut 

 even states that it occupies at different periods of its development 

 different positions ; at first being underneath the epithelium, and 

 after a little while laid bare. The soor is seen with the naked 

 eye, at least, for a short time, below the level of the surrounding 

 epithelium, but never directly on the mucous membrane, but 

 always on epithelial layers ; nor does it exclusively proceed from 

 the glands, since the free glandless edge of the lips, and the 

 upper surface of the nearer glandless part of the tongue, are 

 most frequently attacked. The fungus is always seen to be 

 intimately mixed with the epithelium ; the former is found be- 

 tween the epithelial cells, penetrating all their layers, and mixed 

 up with them. It cannot be said with certainty where the 

 epithelium allows the fungus to penetrate its outer layers ; this 

 seems, however, to be the case in several places, and especially 

 where inequalities in the thickness of the layers and in the 

 separation of the epithelium occur. 



The fungus, in growing amongst the epithelial layers, attacks 

 first the uppermost layers, growing gradually also among the 

 lower, whilst the uppermost are worn out and thrown off by the 

 rapid growth from below. The fungus attaches itself with its 

 filaments partly to the epithelium, partly in the furrows of the 

 surface of the tongue, and all around the papillae, which sit like 

 a red centre in the thrush-ring. It occurs very rarely, according 

 to Bednar and Robin, on the mucous membrane, with ciliated 

 and cylindrical epithelium, but especially on that which contains 

 pavement epithelium, perhaps on account of their stratification, 

 and the possibility of an increased development of cells. It 

 likewise occurs only where there is pavement epithelium in the 

 respiratory passages. Reubold observed such a case in the nose 

 of a child two months old, and repeatedly in children on the aryteno- 

 epiglottic folds, and in the larynx, and on the vocal ligaments. 

 It is slightly distributed over the bronchi and the larynx. It 

 may, however, spread when cicatrized ulcers are found on those 

 parts of the body which are usually accompanied by pavement 

 epithelium. The epithelial appendages which the glands of the 

 rnouth offer at their openings are likewise a favorable place. 

 The fungus is often attached at first to the openings of the 

 glands, and penetrates laterally underneath the epithelium. The 

 secretion-layer of the mucous membrane is not very favorable 

 to its development, on account of its growth and its distance 



