YEASTS AND MOLDS 



22 S 



first one, Achorion Schonleinii, was discovered by Schonlein 

 in 1839, in favus, and is now known as the direct cause of this 

 skin disease. 



Origin. Found in the scaly crusts of favus (Fig. no). 



Form. Similar to Oiidium lactis. 



Growth. Is very sparse. Agar, at body temperature, 

 two types waxy, yellowish mass, and downy, white-plush- 

 like covering. 



In milk it is destroyed. 



Pathogenesis. Causes favus in man, also in animals. 



Trichophyton Tonsurans ("Ring-worm"). Found, in 

 1854, by Bazin, in tinea. 



Fig. no. Achorion Schonleinii (after Kaposi). 



Form. Similar to the achorion or favus fungus. 



Growth. Somewhat more rapid than the favus, and the 

 gelatin quickly liquefied. Old cultures are of an orange- 

 yellow color. Colonies have a star-shaped form. 



On agar and potato the organism can be cultivated by 

 first treating the infected hairs and scales with potassium 

 hydroxid (dilute solution) ; this liberates the spores and dis- 

 solves some of the bacteria which usually contaminates the 

 culture. Some of the colonies are crateriform. 



Pathogenesis. Herpes tonsurans and the various tineae are 

 produced by this fungus. 

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