996 



ASCOMYCETES AND BASIDlOMYCEl ES 



' fragile mycelium. ' To this type belongs, for instance, Trichophyton 

 sabouraudi R. Blanchard. 



When the mycelial spores are square, the filament straight, and 

 its articles long, the mycelium is called 'resistant/ This type is 

 observed, for example, in Trichophyton tonsurans Malmsten. 



Cultivation. — Most Trichophytons can be cultivated, some cannot. 

 The best medium is Sabouraud's maltose agar, the composition 

 of which is the following 



Maltose 



Peptone Chassaing 

 Agar 



Distilled water 



4 grammes. 

 I gramme. 

 1-50 grammes. 

 100 c.c. 



On this medium, however, pleomorphism is of frequent occur- 

 rence. 



Pleomorphism. — Cultures on maltose and other sugar agars of all 

 Trichophytons, with the single exception of T. sabouraudi, becoming 

 old, lose their characteristics and become 

 covered with abundant white duvet. In these 

 cultures, which can be considered degenerate. 



— Trichophy- 

 ton. 



(Preparation from 

 cultures, after Bodin.) 

 I, Chlamydospore ; 2 and 

 3, septate spindle bodies. 



1 2 3 



Fig. 500. — Fructifi- 

 cations. 



, 2, Spore-bearing hyphae 

 (Trichophyton) ; 3, spore- 

 bearing hypha [Micros- 



porum). 



Fig. 501. — Trichophy- 

 ton: Spiral Bodies. 



and are generally called ' pleomorphic,' organs of 'fructification are 

 usually absent. By transplanting these cultures, the same pleo- 

 morphic, downy type of growth will be obtained; never again will 

 the growth show the characteristics of the original young cultures 

 directly obtained from the lesions. It is impossible to return to 

 the original type, even by animal inoculations. 



To prevent pleomorphism, Sabouraud advises the following 

 medium: — 



Agar.. .. .. .. .. 1-8 grammes. 



Peptone Chassaing 

 Water 



3 to 5 grammes. 

 100 c.c. 



