140 



STUDY AND IDENTIFICATION OF MOULDS 



Trichophyton. The fungi of the genus Trichophyton are generally known as 

 the large-spored ringworms. The spores are in chains and may be inside the hair 

 or both outside and inside. Many of them are of animal origin, especially from 

 the horse and the cat. The spores are from 5 to i5/z. 



The mycelium is greatly segmented, shows simple or dichotomous branching, 

 and produces spores within the mycelium. 



T. tonsurans. Gives a crater-like culture with fine marginal rays. Fungus wholly 

 inside the hair. Causes most of the large-spored scalp ringworms and many 

 body cases. 



10. 



FIG. 41. More common fungi, i, Culture of Achorion schoenleini (favus); 

 2, culture of Trichophyton tonsurans; 3, culture of Trichophyton sabouraudi; 4, 

 sporangium of Aspergillus; 5, culture of Trichophyton mcntagrophytes; 6, culture 

 of Microsporum audouini; 7, mycelium and spores of Malassezia furfur; 8, Crypto- 

 coccus gilchristi; 9, A and B, sporangium and mycelium of Mucor corymbifer; 10, 

 Penicillium; n, Saccharomyces tumefaciens; 12, Discomyces bovis. 



It is the T. megalosporum endothrix of Sabouraud. 



The short, diseased fragmented hairs are mouldy looking. The spores are 5 to 6 

 microns. 



T. sabouraudi. Has a heaped-up festooned sort of culture. There is a similar 

 fungus with a violet culture. These cause some of the scalp and beard ring- 

 worms. 



It is easily dissociated in a 2 or 3% solution of caustic potash while T. tonsurans 

 is hard to break up. The hairs are broken off close to the skin, hence "black dotted 

 ringworm." 



