ECTOTRICHOPHYTON MENTAGROPHYTES 1005 



They may be differentiated as follows: — 



A. Grows best on agar without sugars — Pevsicolor. 



B. Grow best on agar with sugars : — 



I. Growth white, elevated centre, powdery surface, radiating 

 furrows. 



{a) Furrows well marked. Pare white — -Mentagrophytes . 

 (b) Furrows poorly marked. Not so white — Radiolatum. 

 II. Growth white, discoid, umbilicated, but later knob in centre; 

 white powdery surface, radiating furrows — Farinulentum. 



III. Growth white, yellowish, dotted with granular projections — 



Grajtulosiim. 



IV. Growth cream white to yellowish, not gTa,nnla,r-~Lacticolor. 



V. Growth white, with umbilicated centre, with numerous radiating 

 projections at periphery. 

 (a) Projections well marked — -Felineum. 

 {h) Projections poorly marked — -Denticuiaium. 



Ectotrichophyton mentagrophytes Ch. Robin, 1853. 



Synonyms. — Microsporon mentagrophytes Robin, 1853; Spovo- 

 trichum mmtagrophytes Saccardo, 1886 ; Trichophyton gypseum Bodin, 

 1902; T. asteroides Sabouraud, 1909; Trichophyton mentagrophytes 

 Robin, 1853. 



Endo-ectothrix; mycelial spores are mostly situated outside 

 the cuticle of the hair, while a few are found in the interior. The 

 latter are 5 to 6 in size; those outside, forming the parasitic 

 sheath, are of very unequal size (2 to 11 /j,^. 



On Sabouraud's agar the growth is ol white colour; the centre 

 is somewhat elevated and covered by duvet ; the rest of the growth 

 has a powdery surface, and often presents several radiating furrows. 

 At the periphery numerous tapering projections are observed. 

 This Trichophyton is of animal origin, being found in horses, cows, 

 dogs, and, perhaps, pigs and sheep. In man it is pyogenic, causing 

 a type of trichophytic sycosis, kerion, and also a pustular type of 

 tinea corporis. 



The following five species are very closely allied to E. mentagrophytes: — - 



Ectotrichophyton farinulentum Sabouraud, igio. 



Synonyms. — Trichophyton gypseum Bodin, 1902, pro parte; Trichophyton 

 /an m/ew^wm Sabouraud, 1910. 



Found in cases of kerion by Sabouraud. On maltose agar the growth is 

 at first discoid, umbilicated, with a white powdery surface and several radiat- 

 ing furrows. Later, the central part becomes raised, forming a knob covered 

 with white duvet. On agar media not containing sugars the growth is at 

 first smooth, without any duvet, of moist appearance and yellow colour; 

 while later the central part becomes downy, and the peripheral portions take 

 a powdery aspect. 



Ectotrichophyton persicolor Sabouraud, 19 10. 



Synonym. — Trichophyton gypseum Bodin, 1902, pro parte: Trichophyton 

 persicolor Sabouraud, 19 10. 



Found by Sabouraud in cases of pustular ringworm of the palms of the 

 hands and of the beard. In contrast to all other species of Trichophytons, it 



