RINGWORM 



121 



The trichophytons are generally known as the large-spored ring-worms. 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 7/1. 



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. 

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



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 mentagrophytes; 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. 



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

 worms. 



T. mentagrophytes. This is the T. megalsporon endoectothrix of Sabouraud. 

 The external spores are in chains or in short mycelial threads, not mosaics of 

 spores, and are of very unequal size (2 to n microns). There are varieties 

 from horse, cat, and bird. The lesions are more inflammatory than those of 

 the endothrix class. Most of the beard and body ringworms belong to this 

 group very few scalp cases. The cultures are finely rayed. 



