2IO 



ESSENTIALS OF BACTERIOLOGY 



which a pointed stem is formed which enlarges to form a globu- 

 lar head, a spore-bulb, or sporangium. The spore-bulb is par- 

 titioned off into cells in which large oval spores lie. When the 

 spores are ripe, a cap forms around the bulb, the walls break 

 down, and the wind scatters the spores, leaving the cap or 

 "columella" behind. 



Growth. Takes place at higher temperatures on acid media. 

 It is not pathogenic. 



Achorion Schb'nleinii. Trichophyton Tonsurans. Mi- 

 crosporon Furfur. These three forms are similar to each 

 other in nearly every particular, and resemble in some 



Fig. 126. Achorion Schonleinii (after Kaposi). 



respects the Oidium lactis, in other ways, the mucors. The 

 first one, Achorion Schonleinii, was discovered by Schonlein 

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

 skin disease. 



Origin. Found in the scaly crusts of favus. 



Form. Similar to Oidium lactis. 



Growth. Is very sparse. On gelatin round white masses 

 inclosed by a zone of liquefied gelatin. 



In milk it is destroyed. 



Pathogenesis. Causes favus in man. 



Trichophyton Tonsurans. Found, in 1854, by Bazin, in 

 tinea. 



