196 



MICRO-ORGANISMS AND DISEASE. [CHAP. 



filament, which subdivides by transverse septa into a series 

 of cylindrical cells ; these by continued growth and division 

 give origin to the ordinary septate branch-hyphae. The 

 formation of conidia proceeds at the ends of these in the 

 same manner as before. The oi'dium lactis forms a whitish 

 mould on milk, bread, paste, potato, &c. 



FIG. 115. FUNGI FROM A FAVUS-PATCH (NEUMANN 



Favus, Herpes tonsurans, and Pityriasis versicolor of man 

 and animals, are, according to the researches of Grawitz, 1 due 

 to a fungus in morphological respects identical with oi'dium 

 lactis. In favus it is known as Achorion Schoenleini, in 

 Herpes tonsurans as Trichophyton tonsurans, in Pityriasis 

 versicolor as Microsporon furfur. Grawitz has shown by 

 artificial cultures on gelatine, that the spherical or oval 



1 Virchow's Archiv, vol. Ixx. p. 560. 



