76 VEGETABLE PAEASITES 



readily gotten rid of than the vegetable parasite. 

 Favus may cover the whole scalp, and destroy all 

 the hair. The person, by scratching, carries off 

 some of the favus mould, and transplants it on 

 other portions of the body. Hence, when of long 

 standing, we are pretty sure to see patches of 

 favus masses on different portions of the body. 

 The vegetable matter also gets, by scratching, 

 beneath the nail, where it takes root and germi- 

 nates, as there it finds all the requisite elements 

 for development ; namely, a steady degree of 

 warmth, moisture, and a quiet resting-place. 

 After the spores have remained for some time, 

 and commenced to germinate beneath the nail, 

 the latter becomes thickened over the affected part, 

 while the color changes, becoming gradually more 

 and more yellow, from the favus mould shining 

 through. As the fungus grows and increases, it 

 gradually presses on the nail, causing further 

 changes, the longitudinal striae become very evi- 

 dent, and fissures are formed. By degrees, as the 

 pressure on the subjacent nail continues, it becomes 

 thinner and thinner, until a perforation occurs, 

 and then a favus cup makes its appearance exter- 

 nally, more or less deformed, however, owing to 



