Injurious to Man. 



17 



in Acari, the larval stage has only six legs instead of eight when 

 it leaves the egg. After undergoing several moults it changes into 

 a nymphal form with eight legs, but differing from the adult in the 

 absence of sexual organs, and finally it passes into the adult stage. 

 The male is considerably smaller than the female and does not 

 make a tunnel, but hides just beneath the skin. Itch * is especially 

 troublesome at night, and may render sleep impossible. This 

 complaint is easily cured by proper treatment. The parts affected 

 should be well scrubbed with soap and hot water, and sulphur 

 ointment applied at in- 

 tervals for several days. 

 Blankets and under- 

 clothes used by the 

 patient should be well 

 washed, 

 ments baked 



and other gar- 



ni 



hot 



oven. 



A remarkable case of 

 skin - complaint caused 

 by the Itch-mite in 

 Indiana (United States) 

 is described by Dr. 

 Robert Hessler in the 

 " American Naturalist " 

 for April 1893. The 

 patient was a middle- 

 aged white man, and 

 partly paralysed. " His 

 entire body was covered 

 with thick, yellowish- 

 white, leathery scales, 



the largest measuring over one inch in diameter, and over one-tenth 

 inch in thickness. He was literally covered with scales, like a fish. 

 . . . (these scales were not crusts or scabs, they were epithelial 

 proliferations). 1 ' Itch-mites and their eggs were found in extra- 

 ordinary numbers in the scales ; Dr. Hessler estimates the number 



Pig. 6. 



Sarcoptes scabici, the itch mite, x 100. 

 (After Canestrini.) 



* Itch has been a source of considerable trouble in the present war amongst 

 the British troops in France, sometimes occurring in a very tenacious form, 

 with a tendency to relapse, even after very thorough sulphur treatment. It 

 was thought that this trouble was due to the Sarcoptes of the horse, but 

 specimens have every appearance of belonging to the human variety of the 

 parasite, the dorsal scales being distinctly longer as compared with their 

 breadth than in Sarcoptes scabiei var. equi. 



C 



