538 



PATHOGENIC FUNGI 



There is evidence that certain varieties are more common in 

 some countries than in others ; for instance, in France Tricho- 

 phyton acuminatum is the more common, whereas in Scotland 

 Trichophyton crateriforme (variety flavum) (Fig. 165 a) is the 



Fig. 165. — a, Trichophyton crateriforme. b, Trichophyton 

 rosaceum. Sabouraud's medium. 



most frequent cause of large-spored ringworm of the scalp, 

 and Trichophyton rosaceum (Fig. 165 6) of ringworm of the 

 beard. In France another coloured variety — Trichophyton 

 violaceum — -is of common occurrence. Similar organisms have 

 been described in the lower animals, such as the horse, calf, 



