RINGWORM 577 



dog, form dry, brown, wrinkled, powdery growths ; 

 others, of bird origin, form purplish growths. 



Microscopically, all the fungi show masses of mycelial 

 threads with spores. They stain with the ordinary anilin 

 dyes and also by Gram's method, and can be mounted in 

 glycerin jelly in the manner described at p. 573. 



Macfayden found that the ringworm organism produces 



FIG. 54. Culture of the ringworm organism. Endothrix form. 



an active peptonising enzyme, and seems to increase the 

 solubility of keratin when grown on it ; no inverting 

 enzyme could be isolated. 



Clinical Examination 



The hairs should be treated first with ether for not less than 

 fifteen minutes and then with caustic potash solution of about 

 7 per cent, strength. In this reagent they may remain for from 

 half an hour to a few hours ; they are then floated on to a slide 

 and carefully covered with a cover-glass. Permanent prepara- 

 tions may be mounted in Farrant's solution or in glycerin jelly. 



M.B. 37 



