A CHORWN SCHCENLEINIL 623 



hits, fowls; and dogs are also subject to it. It grows 

 much more slowly than the ringworm fungus, and is, 

 therefore, not so easily transmitted. Want of cleanli- 

 ness is a predisposing factor. The fungus seems to 

 find a more favorable soil for its development on the 

 skin of persons in weak health, especially from phthisis, 

 than in others. 



Pathologically, the disease represents the reaction of 

 the tissues to the irritation caused by the growth of the 

 fungus. The spores generally find their way into the 



FIG. 85. 



A portion ot a favus infected hair. Magnified. 



hair-follicles, where they grow round the hair-seat 

 (Fig. 85). The favus fungus grows in the epidermis, 

 the density of the growth causing pressure on the parts 

 below, thus crushing out the vitality of the hair and 

 giving rise to atrophic scarring. The disease shows a 

 marked preference for the scalp, but no part of the 

 skin is exempt, and even the muco-us membranes are 

 liable to be attacked. Kaposi has reported a case in 

 which a patient suffering from universal favus died, 

 with symptoms of severe gastro intestinal irritation, 

 which was found after death to be due to the presence 



