544 TRICHOMYCETES, ACTINOMYCETES, HYPHOMYCETES 



vitality, as poorly nourished children and consumptives, appear to 

 be relatively more readily infected than the more robust. The organ- 

 ism spreads slowly and the disease is a chronic one, difficult to influence 

 by treatment. The initial lesions are small red pimples, which soon 

 enlarge somewhat, forming gray or sulphur-yellow crusts grouped 

 around the base of hairs. These crusts, known as scutella (singular 

 scutellum), slowly increase in size peripherally and tend to coalesce. 

 If a scutellum is removed it is found to be somewhat thicker in the 

 centre and cup shaped. Examined under the microscope it consists 

 of a dense, matted mycelium which in the centre may be so compact 

 as to obscure the individuality of the filaments; at the periphery the 

 growth is less luxuriant and the individual filaments are clearly 

 defined. Spores are very numerous at the centre of the scutellum, but 

 at the periphery they are much fewer in numbers. The hair enclosed 

 by the colony of mold is destroyed. 



The organism, Achorion schonleinii, was first observed by Schonlein 

 in 1839. It is readily cultivated at room temperature upon gelatin, 

 or better, upon agar at 30 to 35 C. Media with a neutral or slightly 

 alkaline reaction are more favorable for its development than acid 

 media. In this respect Achorion schonleinii differs culturally from 

 the majority of molds. Material taken directly from the centre of 

 a scutellum, streaked upon agar, usually develops into white or gray 

 colonies in which the mycelia and spores are readily recognizable with 

 the lower powers of the microscope. Frequently adventitious organ- 

 isms overgrow the more slowly developing favus parasite. If a piece 

 of the scutellum is ground in a sterile mortar with sterile powdered 

 water glass and the powder well distributed upon gelatin-agar or 

 Sabouraud's medium, 1 pure cultures are usually obtained. The yellow- 

 brown colony usually exhibits a central depression resembling some- 

 what that of the scutellum. The swollen ends of the filaments are 

 quite characteristic. There appear to be several varieties of the mold, 

 but there is only one type of the disease. 



Herpes Tonsurans. Herpes tonsurans, ringworm, Tinea tonsurans 

 or sycosis is a disease chiefly of the hairs of the head or beard, but it 

 often spreads to the skin as well, Tinea circinata. The axillary or 

 pubic hairs are occasionally involved. It occurs in children rather 



1 SABOURAUD'S MEDIUM. 



Peptone (Witte) 2.0 grams 



Glycerine, redistilled, pure 4.0 grams 



Water 100.0 c.c. 



Agar 1.2 grams 



