146 APPENDIX. 



fermentation they give rise to a pigment in the culture media. 

 They grow upon gelatine which they do not liquefy. 



Saccharomyces Mycoderma. This yeast forms a mould-like 

 growth, a skin, on the surface of fermented liquids, but does not 

 cause any fermentation itself. It forms the common "mould" 

 on wine, preserves, and "sour krout." 



Oidium. A form which seems to be the bridge between the 

 yeast and the moulds is the oidium. Sometimes it resembles 

 the yeasts, sometimes the moulds, and often both forms are 

 found in the same culture. Several are pathogenic for man. 



Oidium Lactis. 



Origin. In sour milk and butter. 



Form. The branches or hyphens break up into short rod-like 

 spores. No sporangium, as in moulds. 



Growth. In milk it appears as a white mould. 



Artificially cultured on gelatine plates, or milk gelatine plates, 

 it forms satin-like, star-shaped colonies, which slowly liquefy. 

 Under microscope the form of the fungus is well seen. 



'Agar Stroke Culture. The little stars, very nicely seen at first ; 

 then the culture becomes covered with them, causing a smeared 

 layer to appear over the whole surface, with a sour odor. 



Properties. The milk is not changed in any special way. It 

 is not pathogenic for man or animals. It is found when the 

 milk begins to sour. 



Oidium Albicans. (Soor.) Thrush Fungus. 



Origin. Mucous membrane of the mouth, especially of infants. 



Form. Taken from the surface of the culture, a form like 

 yeasts ; but in the deeper layers, mycelia with hyphens occurs. 



Growth. Not liquefying ; snow-white colonies on gelatine 

 plates. 



Stab Culture. Radiating yellow or white processes spring from 

 the line made by the needle, those near the surface having oval 

 ends. 



Potatoes. The yeast form, develops as thick white colonies. 



Bread Mash. Snow-white veil over the surface. 



Pathogenesis. In man the parasitic thrush, or "white mouth,"' 

 is caused by this fungus. In the white patches the spores and 

 filaments of this microbe can be found. Rabbits receiving an 



