DISEASES OF THE OX AND SHEEP. 447 



the wool taken from a sheep afflicted with the scab, on account 

 of the possibility of transmitting the malady to other sheep. 



CERTAIN EXTERNAL PARASITES OF THE SHEEP 

 OTHER THAN THAT WHICH CAUSES SCABIES, 

 TOGETHER WITH AN ACCOUNT OF THE PARA- 

 SITIC DISEASE OF THE BREATHING ORGANS 

 OF LAMBS, OR VERMINOUS BRONCHITIS. 



We spoke above of the creatures which produce scabies, and 

 now we pass on to the consideration of the other parasites 

 whicli infest the skin of the sheep. Of these the best known 

 are those which, under the name of sheep-fags, are very familiar 

 to farmers. Before, however, we describe these creatures, we 

 have in the first place to point out that in the fleeces of sheep 

 maggots are occasionally liable to be deposited by the large 

 blow-fly {Sarcophaga canaria) in hot and sultry weather. 



The attacks of the fly, the maggots of which infest the sheep, 

 are owing to the large quantity of organic material which is 

 present in the sheep's fleece. The blow-fly, seeking for suitable 

 quarters wherein to lay her eggs, is attracted by this, and the 

 consequence is that, unless they are killed without delay, these 

 disgusting creatures thrive and distress the sheep, sometimes 

 almost beyond endurance. Moreover, especially in the case of 

 horned sheep, wounds may be inflicted on one another, and in 

 these wounds the blow-fly may find just the places required for 

 the growth of her offspring. Wherever the noisome creatures 

 gain their footing, they may burrow into the skin and devour 

 the flesh of the sheep to such an extent, that even death may 

 ensue. 



It has been recommended that a mixture of oil and sulphur, 

 sufficiently thick for convenient use, should be applied to 

 wounds liable to be infested with maggots, by the help of a 

 brush, the preparation being carried about in a suitable tin. 

 Probably some antiseptic ointment, such as that of carbolic 

 acid or that of salicylic acid, is preferable for this purpose. The 

 flock should be clipped rather early, if the sheep are troubled 

 with these creatures, and after being shorn they should be 

 dipped. If the heads are affected, the preparation used should 

 be applied once a week, or at least once a fortnight during the fly- 



