The Sheep- Scab. 13 



tacked, and the long, coarse-woolled sheep of 

 open fibre in preference to those of shorter fibre. 

 The close-grown fine-woolled Merino sheep 

 will long withstand the inroads of this parasite, 

 but not even they are exempt from the conta- 

 gion. The power of the healthy merino sheep 

 to resist for a time this insinuating insect is 

 probably due to an abundance of yolk and the 

 density of the fibre acting as an obstacle to its 

 penetrating to the skin. 



Symptoms of Scab. 



It is seldom the case that the first attack of 

 the acari is observed, even by the careful super- 

 intendent, for the mites are barely visible to the 

 naked eye, and their presence causes no partic- 

 ular irritation to the sheep, until they have been 

 located in the skin for several days. The earli- 

 est evidence that sheep are infected with this 

 plague, is a certain restlessness and uneasiness, 

 and unless the shepherd is on the alert, this 

 symptom is passed by unnoticed; consequently 

 the disease is rarely discovered until it is fully 



