56 MICROBES, FERMENTS, AND MOULDS. 



herpes; and that parasitic herpes may also be pro- 

 duced on the back of the hand by the transference 

 of the fungus from a patch of Tinea tonsurans. 



The fungus may be transmitted to cats, dogs, and 

 horses, who thus become agents of the contagion. A 

 fresh study of the disease has been recently made by 

 an Englishman, Dr. Thin, and he also regards it as 

 identical with herpes, or Tinea circinata. 



According to this observer, the contagion is not 

 transmitted by floating spores, but only by direct 

 contact, and especially by the exchange of hats and 

 caps so common among school -children. 



Experiments in artificial culture in milk, carrot- 

 juice, or aqueous humour show that the fungus cannot 

 be developed when the hair on which the spores are 

 is entirely submerged ; a certain degree of moisture is, 

 however, necessary, which is probably more frequentty 

 found on children's heads. In adults, the bulbous root 

 of the hair is dryer between the follicle and the skin. 

 The parasite may be destroyed by causing an inflam- 

 mation of the part affected, since the serous effusion 

 thus produced places the hair in the same conditions 

 as in the culture-liquids in which it is completely 

 covered, and not floating. 



Pityriasis versicolor is produced by a fungus 

 resembling the foregoing, termed Microsporon furfur. 

 It grows between the cells of the epidermis, and 

 effects their rapid degeneration. The hyphae have 

 long articulations, intermixed with round spores, not 



