PARASITES AND PARASITIC DISEASES 



231 



To destroy mange mites it is necessary to scrub the infested 

 parts of the body with a warm coal-tar dip solution, or decoction 

 made by boiling 1^ pounds of tobacco leaves in 8 quarts of water. 

 The harness, currycombs, brushes, and other stable paraphernalia 

 should also be thoroughly saturated with the solution to kill any 

 mites which may have crawled onto them. Treatment ought to 

 be repeated in a week or ten days, to destroy such young mites as 

 may have hatched from eggs in the meantime, for the latter resist 

 the action of these parasiticides. It takes persistent work effect- 

 ively to eradicate mange. 



LICE 



Lice are small, wingless insects. The females lay oval eggs, 

 called "nits," and secrete a glue-like substance that attaches the 



Fig. 65. — Hematopinus macrocephalus or louse. This is the common horse- 

 louse, greatly enlarged. 



eggs to the hair. After a varying period the young and complete 

 insect raises the operculum from the large end of the egg, opposite 

 to the point of attachment, and crawls out. In a short time it 

 develops into an adult louse and is capable of reproduction. 



