OF THE HUMAN SKIN. 75 



propagation of the affection from the scalp to other 

 parts of the body. The hairs lose their gloss, be- 

 come dull and dry, and assume a grayish or red- 

 dish color. They break more readil}^ than 

 natural, are often twisted or split longitudinally, 

 and pull out more easily. When this vegetable 

 mould has grown a long time on the scalp, the 

 hair follicles are destroyed, and the hairs fall out, 

 producing permanent and irremediable baldness. 

 The sebaceous follicles, which secrete the natural 

 and necessary oil or fat of the skin, are also de- 

 stroyed, so that the parts affected become dry, and 

 like parchment to the feel. The odor is quite 

 characteristic, resembling that of mice; ^.e., a 

 sort of mouldy smell. 



The presence of the parasite, and the consequent 

 itching and scratching, produce a certain amount 

 of eruption and rash over the parts affected ; the 

 neighboring glands may also swell up, and form 

 lumps under the skin. The dirt which predisposed 

 to favus, of course predisposes to the presence of the 

 animal j)arasite which inhabits the scalp, and which 

 w^e have already described. This increases the 

 itching, and complicates the whole course of 

 the disease. They are, however, much more 



