OIDIUM ALBICANS. 201 



was, however, never observed by any modern writer, although it 

 seems to me that the possibility of their occurrence is not to be 

 excluded on physiological grounds. The horny tissues are closely 

 related to the epithelial tissues, and only separated in their wider 

 life the one from another. In a diseased state, nature is anxious 

 to restore the epidermis which was just removed, and the forma- 

 tion of epithelial cells must therefore take place, which the fungus 

 might occupy as its seat. Thus the growth of the thrush on 

 the above places of the skin becomes intelligible. (See section XII, 

 and what is stated there of the nail-fungus.) It has already 

 been remarked that the thrush occurs occasionally on ulcerated 

 surfaces and diphtheritic membranes; according to Robin, the 

 elements of the fungus are, however, found on these places only 

 in the purulent mucus of the diphtheritical ulcers, which fact he 

 explains by the accumulation of the epithelial masses, especially 

 of pavement epithelium in such exudations. 



Berg thinks that the thrush-fungus grows also externally on 

 the body, especially at a temperature of 30 35 C. (98 Fahr., 

 blood-heat), and in albuminous liquids forming an acid ; and is 

 of opinion that its development outside of the body is divided 

 into two different forms, now in the form of sporidia, giving rise 

 to a mouldy membrane on the surface of the liquid, and then in 

 a stalked form, exhibiting radiating and entangled fibres. Im- 

 mediately afterwards, it is, however, stated by Berg, that he 

 obtained a thrush- like mouldy membrane, in a liquid which con- 

 tained a solution of milk-sugar and a piece of the stomach of a 

 new-born child ; likewise in a liquid of mucus and cane-sugar, 

 although he could not discover any thrush-fungi, either in the 

 stomach or in the mucus. The same occurred after some 

 weeks in closed vessels in solutions of milk-sugar, made of human 

 and cow's milk. Vegetations like the thrush-fungus became 

 rapidly manifest in the serum of the blood, diluted a little with 

 water and acid, more rapidly still when a little cane-sugar was 

 added. Solution of caustic potash, which dissolves easily the 

 protein-compounds, clearly proved the vegetable nature of the 

 above formations. A similar process is noticed in milk, which 

 seems to be accelerated by a mutual action between protein- 

 compounds and certain acids. The thrush-fungus seems to be 

 nothing more, according to these considerations, than a kind of 

 fungus occurring as an ordinary mould on animal textures and 

 animal liquids which are left uncovered, and the fungus nothing 



