2 so 



SPECIFIC MICRO-ORGANISMS 



specifically identical with, Achorion schoenleinii. The exact 



relationships of the parasites are not very fully settled as yet. 



Microsporon Audouini. — This mold is found growing in the 



hair-shaft in alopecia areata. If the ha,ir be pulled out it breaks 



near the lower end and the oval 

 conidia and jointed threads of the 

 parasite may be demonstrated by 

 macerating this broken end. The 

 disease is very contagious, chronic 

 and resistant to treatment, but 

 proceeds without inflammation or 

 subjective sjTuptoms, the conspic- 

 uous sign being loss of the hair. 

 Cultures grow slowly and are snow 

 white. Animal inoculation is rarely 

 successful. 



Microsporon 'Pvcdai. — This mold 

 is found in the superficial layer of 

 the skin in pityriasis versicolor, as 

 short thick hyphae 3 to 4m wide by 

 7 to 17,11 long, together with abuhdant 

 doubly contoured single conidia. 

 Pityriasis versicolor occurs most fre- 

 quently on the skin of the chest and 

 is one of the commonest affections 

 of the skin. 



Tricophyton Actuninatum. — The 

 niold invades the hair shaft and 

 causes it to break off close to the 

 surface of the skin. In such a hair long chains of oval cells of 

 the parasite may be seen. The parasite also attacks the skin and 

 produces ringworm. Several other species of tricophyton are 

 distinguished. These parasites are concerned in the causation of 

 barber's itch, eczema marginatum, tinea cruris, and other skin 

 affections of this type. 



Pig. 102. — S porotrichum 

 sohencki. Cultures on the glu- 

 cose-pepton agar of Sabouraud. 

 (After Gougeroi.) 



