RINGWORM 575 



The first of these groups is exclusively of human origin, 

 causes ringworm of the scalp, body and beard, and has 

 a marked tendency to affect the interior of the hairs only , 

 and hence the organism has been termed the Trichophyton 

 megalosporon endothrix. The other group is of animal 

 origin (horse, ox, pig, deer, cat, dog, birds), causes 

 ringworm of the body, beard and nails, and the spores 

 are met with chiefly on the outside of the hairs ; hence 

 the fungus is termed the Trichophyton megalosporon 

 ectothrix. 



The endothrix form occurs later in childhood, and is not 

 so persistent as the Microsporon. Microscopically, the 

 fungus is seen to consist of beaded threads, which are 

 rounded or ovoid spores arranged end to end. The 

 ectothrix form rarely attacks the scalp, and suppuration 

 is common. Microscopically appearances differ ; generally 

 the spores are arranged in chains, but the sporulation is 

 less regular than in the endothrix. The spores in the 

 endothrix and ectothrix varieties measure 4 /z to 12 ^ in 

 diameter. 



The ringworm fungi can be readily cultivated on all 

 the ordinary media beer-wort agar and beer-wort gelatin 

 being especially favourable. They form whitish fluffy 

 growths with rapid liquefaction of gelatin. In order to 

 obtain cultivations the diseased hairs or stumps are 

 removed by forceps and placed on a sterile glass slide. 

 The aerial portion of the hair is then cut away by means 

 of a sterile scalpel, and the diseased portion is divided into 

 small fragments. These can be picked up with a moistened 

 platinum needle and transferred to the culture media, 

 preferably beer-wort agar. In some cases a pure culture 

 is thus obtained, but in others further treatment is neces- 

 sary. When the Trichophyton or Microsporon has thrown 

 up its aerial hyphse the plug of wool is removed from the 

 tube and the mouth well flamed ; the tube is then held 



