372 MICROBIOLOGY 



Emery 2!) found that Microsporum Audouini acts both 

 mechanically and chemically in the production of ringworm. 

 The mechanical action is produced chiefly by the splitting 

 apart of the component parts of the hair and by pressure ex- 

 erted on the shaft and bulb. The chemical action is due to the 

 effect of a toxin that causes slight folliculitis. 



Trichophyton gypseum (Sabouraud). Sabouraud 30 first 

 isolated this organism from horses. It also has as its primary 

 host the cow, dog, pig and possibly other animals. He culti- 

 vated it on beef wort agar and maltose peptone agar. The 

 mycelial hyphae were divided transversely. In the young 

 stage, septa are not visible near the ends which are rounded. 

 The hyphae are irregularly branched. Many short branches 

 are given off. Fitzgerald describes this organism in consid- 

 erable detail and gives illustrations of the lesion it produced on 

 the hand and also of the fungus. M'Fadyean 31 studied the 

 cultural characters of T. tonsurans and found it produced an 

 enzyme which liquefied gelatin, and that the fungus would 

 grow on a medium consisting entirely of keratin. 



29 Emery. Jour, of Path, and Bact, Vol. VII (1900) p. 400. 



30 Sabouraud. Les Trichophyties humaines. Paris, 1894. 



31 M'Fadyean. Jour, of Path, and Bact, Vol. Ill (1895) p. 176. 



