296 APPLIED BACTERIOLOGY 



DISEASES DUE TO PARASITIC FUNGI. 



The following diseases, which are due to parasitic fungi, 

 are of practical importance, viz., pityriasis versicolor (Micro- 

 sporon furfur), thrush (Oidium albicans), favus (Achorion 

 Schonleinii), and ringworm (Trichophyton tonsurans). 



Microsporou Farfiir. 



This organism, which is found in pityriasis versicolor, 

 belongs to the same family as the Tricophyton tonswans 

 and resembles it in microscopic appearance ; it has not yet 

 been artificially cultivated. 



Thrush. 



In the white patches sometimes found in the mouths of 

 infants fed on milk, the spores and filaments of an organism 



Fig. 23.— Mycodebma Albicans (Thrush). 



can be distinguished ; this thrush fungus is by some con- 

 sidered to be identical with the Oidium albicans ; it can be 

 grown on milk, bread, gelatine, or agar, and on potato. On 

 all these media it produces a very copious growth, the 

 growth on potato being a remarkably thick, raised patch. 

 If an intravenous injection is administered to rabbits, the 

 animals die in about thirty-six hours, when their viscera 



