MITES. 



197 



2. Blood-sucking mange-mites living on the outer 

 surface (Dermatocoptes) ; 



3. Mange-mites which merely devour scales of the 

 epidermis (Dermatophagus). 



It is obvious that sarcoptic scabies is not so easily 

 cured in the same host as the dermatocoptic scabies, 

 since the mites causing the former dig their passages 



Fig. 125. — Mange Mite of the Pig ^Sarcoptes scaNei, var. sui'g), 

 seen from the ventral side. 



into the epidermis, while those causing the latter at 

 least remain on the surface. Dermatophagic scabies 

 is most easily got rid of, since the mites which 

 cause it not only remain on the outer surface of the 

 skin, but also, instead of holding fast, run about here 

 and there; it is easily understood that this kind of 

 mange can often be removed by simple brushing. 



