FILAMENTOUS AND BUDDING FUNGI. 



345 



ton tonsurans (discovered in 1845 by Gruby and Malm- 

 sten), which, partly alone and partly in mixed infection 

 with bacterial excitants of inflammation, is the cause of the 

 disease. The fungus appears especially in the form of 

 extended, slightly branched and straight mycelia, whose 

 width is less and whose segments are comparatively 

 much shorter than those of the favus-fungus. The conidia 

 of the trichophyton resemble those of the achorion, al- 



Fig. 78. Root of hair in tinea barbae, showing early invasion of trichophyton in root- 

 sheaths and upper part of bulb. 



though they are somewhat smaller and, above all, less 

 numerous. These fungous elements lie between the epi- 

 dermic scales, between and in the sheaths of the roots of 

 the hair. In the less changed hairs the mycelium pre- 

 ponderates ; when the trichophytic infiltration is consider- 

 able, the spores are more abundant. 



The trichophyton may be conveyed to human beings 

 from animals. It occurs in dogs, cats, cattle, and horses. 



