360 THE DOMESTIC SHEEP. 



drop from the diseased sheep on to the ground, where other 

 sheep may lie, and others lying on the same ground, will of 

 course become infected. They are rubbed off as the sheep 

 scratch themselves in the vain effort to get relief, on 

 fences, walls, and other places, and the infection easily spreads 

 from these. As a flock passes on the road, another following will 

 easily pick up the contagion. Sheep cars are notorious sources 

 of infection obviously, and one scabby animal may infect thou- 

 sands on a range which may follow in its track. 



This form of the disease is specially different from the other 

 two, and cannot be mistaken for either of the others. It is indis- 

 pensable, considering the enormous increase in the numbers 

 of it, that instant measures be taken for its destruction and the 

 saving of the flock. Fortunately the location of the pest makes 

 its first appearance so prominent that no mistake can be made 

 in distinguishing it, and then the remedy is easy. This is to wash 

 the parts affected in any of the dips to be procured in the mar- 

 ket, or of any of the ointments made for this purpose, or to apply 

 any kind of sweet thin oil rubbing it well into the scabs after 

 washing with carbolic or tar soap, and repeating the treatment 

 until it is certain that it has been effective. 



THE COMMON SCAB MITE-PSOROPTES COMMUNIS. 



This is the most to be feared by the shepherds of all the ex- 

 ternal parasites of the flock. It is a much larger insect than the 

 head mite, and is visible to the unaided eye if gathered on some 



FIG. 29. Male and Female Scab Insects- 

 white surface. It has been so neglected, as seems to be the 

 rule, left for some one else to attend to, that it has gained an 

 almost impregnable footing through the whole world. It has thus 

 become the subject of legislation in many countries, but this as 



