PSOROPTIC MANGE-SHEEP SCAB. Glo 



Experience has shown that in some eases apparently healthy sheep 

 have hecome n.fected in places where no sheep have been kept for four 

 eight, twelve, or even twenty-four months. The conditions underlyino- 



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this infection are not thoroughly understood. Possibly some of the 

 eggs have retained their vitality a long time and then hatched out ; 

 possibly the vitality of the fecundated female has also played a role .■ 



