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Dermal()(lccte> e([ui (derlach). 



The second variety of mange is caused by the sarcoptes eqiii These- 

 creatures penetrate the skin, raising up a small knotted elevation, with a 

 small passage, at the extremity of which the acarus resides. This acarus 

 has a tendency to wander about, and is especially abundant on the sides of 

 the neck and withers, from whence it spreads over the surface of the body,, 

 excepting those parts covered by long hair. The pimples, if examined, are 

 found to be hard scabs, situated on a moist basis. As the crusts become 

 drier, the skin becomes thickened, wrinkled, and fissured. Mange caused by 

 this acarus is rare. The course of the disease is slow, and may even cause 

 death from irritation and exhaustion. Dr. Fleming, F.R.C.V.S., LL.D., 

 has seen the disease in the Crimea. The sarcoptes do not li\e in colonies 

 like the foregoing, but lead an independent existence. 



The third variety of mange is caused by the symbiotes equi, a creature 

 which lives in colonies and invades tlie limbs, not burrowing, but merely 



