Sarcoptida, or Itch Mites 



75 



diet, or "bad blood." This was in spite of the fact that the mite was 

 known to Mouffet and that Bonomo had figured both the adult and 

 the egg and had declared the mite the sole cause of the disease. In 

 1834 the Corsican medical student, Francis Renucci, demonstrated 

 the mite before a clinic in Saint Louis Hospital in Paris and soon 

 thereafter there followed detailed studies of the life history of the 



various itch mites of 

 man and animals. 



The disease is a cos- 

 mopolitan one, being ex- 

 ceedingly abundant in 

 some localities. Its 

 spread is much favored 

 where large numbers of 

 people are crowded to- 

 gether under insanitary 

 conditions and hence it 

 increases greatly during 

 wars and is widely dis- 

 seminated and abundant 

 immediately afterwards. 

 Though more commonly 

 to be met with among 

 the lower classes, it not 

 infrequently appears 

 among those of the most 

 cleanly, careful habits, 

 and it is such cases that 

 are most liable to wrong 

 diagnosis by the physi- 

 cian. 



Infection occurs solely through the passage, direct or indirect , 

 of the young fertilized females to the skin of a healthy individual. 

 The adult, oviparous females do not quit their galleries and hence 

 do r.ot serve to spread the disease. The young females move about 

 more or less at night and thus the principal source of infestation is 

 through sleeping in the same bed with an infested person, or indirectly 

 through bedclothes, or even towels or clothing. Diurnal infestation 

 through contact or clothing is exceptional. Many cases are known 

 of the disease being contracted from animals suffering from scabies, 

 or mange. 



58. Scabies on the hand. From portfolio of Dermo- 

 chromes by permission of Rebman & Co., of 

 New York. Publishes. 



