THE SKIN 



249 



The rubbing post has been used with fair success as a means of 

 holding louse infection in check. One or more posts are set in pens 

 and ropes wound tightly around them for a distance of two feet from 

 the ground. These ropes should be moistened with crude petroleum 

 from time to time. The swine will annoint themselves and destroy 

 most of the lice by rubbing themselves against these posts. 



Mange 

 Mange, or infestation of swine with some Acari or mange parasites, 



Pig. 56. Male hog louse. (Farm- 

 ers' Bull. 1085, Dept. Agrl.) 



Pig. 57. Pemale hog louse and 

 egg attached to hair. (Parmers' 

 Bull. 1085, Dept. Agri.) 



is not a rare condition in this country, where two forms of mange 

 occur — sarcoptic and demodectic. 



Sareoptic Mange 



Sarcoptic mange is enzootic in certain sections. It is caused by 

 infestation with the Sarcoptes scabiei, var. suis. The life cycle of 

 this parasite is as follows : 



The ovigerous female burrows into the skin, forming galleries in 

 •which she deposits her eggs, usually about fifteen in number. The 

 ova hatch in from five to ten days into six-legged asexual larvte which 

 may remain in the galleries or pass out under the scabs, and in two to 



