TRICOPHYTON MENTAGROPHYTES 



685 



The growth on beer-wort agar and on maltose-agar assumes the form of 

 a projecting cone with a wide base and traversed by deep sulci passing from 

 the apex to the base : the colonies are creamy- white in colour and tinted with 

 pinkish-grey or greyish-brown circles. On potato the parasite grows as a 

 straight brown streak and is covered with a very fine light brown powder. 



3. Tricophyton violaceum. 



[T. violaceum occurs in 15 per cent, of cases of tricophytic ringworm in 

 children in London (Colcott Fox). It is characterized by the violet colour of 

 the culture when about 3 weeks old. The culture is more or less acuminate.] 



4. Tricophyton sulphureum. 



[This tricophyton seems to be peculiar to England, for while Colcott Fox 

 found it in 21 per cent, of cases of scalp ringworm in children due to trico- 

 phyta in London it is rare in France, and four cases seen by Sabouraud were 

 imported from England. The culture resembles the crater-like form of 

 T. tonsurans, and is sulphur-yellow in colour.] 

 "f J 

 [B. The Endo-ectothrix species.] 



1. Tricophyton mentagrophytes. 



[Syn. Tricophyton gypseum Bodin ; Tricophyton asteroides Sabouraud.] 

 This parasite which gives a white growth in culture, and is described by 



FIG. 325. Tricophyton mentagrophyies (Endo-ectothrix). Hair from the 

 beard. (After Sabouraud.) 



