TRICHOPHYTONEAE 527 



TRICHOPHYTON 



Trichophyton Malnisten, Trichophyton tonsurans harskarande Mogel, 1845 ; 

 (tr. Arch. Anat. Physiol. Wiss. Med. [Miiller] 1848: 1-19, 1848). 



Type Species: Trichophyton tonsurans Malmsten. Since Malmsten did 

 not cultivate his organism, botanists have been agreed to refer the very com- 

 mon species of tinea tonsurans with a crateriform colony, which Bodin dis- 

 cusses under the name Trichophyton crateriforme Sabouraud, to Trichophyton 

 tonsurans Malmsten. 



Only chlamydospores, arthrospores, and aleurospores present, the latter 

 usually on simple thyrses; lesions of the tinea tonsurans tj^Q with the rela- 

 tively large arthrospores wholly in the hair. In a few species (in the early 

 stages of infection, the arthrospores may be found both without and within), 

 the giant colony velvety, neither moist and glabrous nor very powdery; if 

 infection is transferred to the glabrous areas, usually there are produced dry 

 scaling areas with very little or no inflammation. 



This genus, comprising the sections Neoendothrix and Efidothrix of Sabou- 

 raud, is a natural group of closely related species. In the Neoendothrix sec- 

 tion, usually producing sycosis, rarely tinea capitis, the early stage of infection, 

 during which arthrospores are produced both outside and inside the hair, per- 

 sists for a longer time than in the other groups hence, in examining a large 

 number of hairs of a given area, about one-fifth will ordinarilj^ show this early 

 stage. The section Endothrix of Sabouraud usually producing prepubertal 

 tinea capitis might well be divided into two subsections: Malmstenia, the more 

 primitive with its crateriform colony in which the hair or a considerable portion 

 thereof is bent and folded and embedded in the scale (Trichophyton tonsurans 

 type) and Sahouraudia, the more advanced type with an elevated or acuminate 

 type of colony and with the hair breaking off sharply at the mouth of the 

 follicle (Trichophyton Sahouraudi type). 



Key to Trichophyton 



Colonies crateriform at first, becoming cerebriform, lesions of the Neoendothrix type, usually 

 sycosis, rarely tinea capitis. 

 Colony white, becoming cream color and yellowish in the center, crackled, marginal rays 



distinct and unequal. T. flavinn. 



Colony soon sulphur yellow, then light brown, becoming red brown. 



T. oohropyrraceum. 

 Colony remaining white, outer folds radiating, inner less contorted than in T. flavuvx, 

 margin powdery, rays less visible, folds cracking in old colonies. 



T. plicatile. 

 Colonies remaining crateriform, lesions of the Malmstenia type, usually tinea capitis, pre- 

 dominantly prepubertal. 

 Colony zonate, center dark cinereous, then lanuginous, clear green, a narrow darker ashy 

 zone, a green zone and a white margin; subcultures with black center and zones 

 of dark brown (Havana cigar color). T. bicolor. 



Colony not zonate, brown. 



Colony smoke brown (color of dead leaves), umbo in center of crater soon 

 disappearing, periphery with periclinal furrows about 1 mm. apart. 



T. fwnatwn. 



