MOLD OR HYPHOMYCETE GROUP 409 



scales from an infected area with a solution of KOH, which removes 

 most of the bacteria without materially injuring the mold spores. 

 Potato is a favorable medium for growth. A rather velvety, 

 wrinkled, relatively heavy, membrane forms which may be white 

 or colored. Gelatin is slowly liquefied. 





Fig. 183. Trichophyton tonsurans from agar plate culture (Giinther). 



Pathogenesis. The disease in all animals is characterized by 

 the formation of scales, the falling out of hair, with or without 

 suppuration. It is well demonstrated that it can spread from 

 one species of animal to another by contact. 



Achorion schoenleinii 



Synonyms. O'idium porriginis; Oospora porriginis, and many 

 described species of Achorion. Opinions differ as to whether 

 one polymorphic species or many species are represented. 



Diseases Produced. Favus, tinea favosa, in man, animals, 

 and birds. 



The organisms grouped under this name have been separated 

 into a large number of species by some investigators. Doubtless 

 more than one species should be recognized, but they have not 

 been sufficiently differentiated. 



Morphology. The organism is made up of more or less branched 

 hyphse, 3 to 5 f* in diameter. Spores are formed by the breaking 

 up of the filaments into oval or somewhat cubical spores, 3 to 8 



