PARASITOLOGY. 



57 



Fig. 18— Male Fsoroptes Communis, variety Ovis, Photomicrograph 

 lx% inch, 

 a, Head parts. b, Legs. 



c, Body. (Thorax and abdomen are not distinctly marked macroscop- 

 ically.) 



asites, cause the hair to become matted and present 

 a stairy appearance. Later the hair falls out and 

 reveals scabby hairless patches. The mode of spread 

 of the contagion, and the treatment, are the same as 

 in scabies produced by other parasites. If the dis- 

 ease is not treated the animal becomes thin in flesh, 

 anemic, and finally dies. 



PsoROPTES Communis, variety Bovis (Bovis — ox). 



History. — Widely distributed in the United States; 

 found in the middle West and South. 



Animal Inksted. — This is the common scab para- 

 site of the ox. 



Condition Produced. — The back, loins and croup 

 are the first parts to become infested. On account 

 of the difficulty in scratching these parts the scabs 

 pile up, often an inch in thickness. The animal rubs 

 and licks himself as a result of the pruritus, gradu- 



