OF THE HUMAN SKIN. 15 



of the person affected. . This itching calls for 

 scratching, which finally produces a papular, or 

 eczematous eruption, the seat of which, however, 

 points towards the cause, and a careful examin- 

 ation will detect the pediculi on the hair close to 

 the skin, and the nits also near by. As these 

 parasites do not cause so much irritation as the 

 loediculi cajpitis, and infesting portions of the body 

 covered by the clothing, they often remain unob- 

 served, frequently living and thriving on an indi- 

 vidual for an indefinite period, especially among 

 those whose change of raiment or ablutions occur 

 about as often as the equinoxes, but not with the 

 same regularity. The ravages of the head-louse, 

 and the ravages of the finger-nails and comb to 

 allay the itching of the scalp, often produce, as we 

 said, an artificial eczema, or inflammation of the 

 skin, which, when long continued and excessive, 

 may finally cause the glands in the neighborhood 

 to swell up or break down into abscesses on the 

 neck, for instance, or behind the ears. This rarely 

 occurs with the pediculus pubis; yet in a person 

 predisposed to glandular swellings, the glands in 

 the groin may swell up from long-continued 

 scratching, and consequent eczematous eruptions, 



