Reports to various Correspondents. 17 



GKOUP E. 



Animals which concern Man as causing bodily injury or 

 disease, both possibly of a deadly character, to (A) his 

 stock of Domesticated Animals, or (B) his Vegetable 

 Plantations, or (C) to Wild Animals in the preservation 

 of which he is interested, or (D) Plants in the preserva- 

 tion of which he is interested. 



SUB-GROUP A. ANIMALS WHICH CAUSE BODILY 

 INJUEY OR DISEASE TO MAN'S STOCK OF DOMES- 

 TICATED ANIMALS. 



Sheep Scab. 



In answer to an enquiry from Mr. E. G. Wheler, Commissioner to 

 His Grace the Duke of Northumberland, concerning the life-history 

 of the Scab-mite, the following Report was sent. 



This Report was further enlarged at the request of the Land 

 Agents' Society, and appeared in amended form in their " Journal." * 



Sheep Scab. 



Sheep Scab is caused by three different Acari, namely : (1) Sar- 

 coptes scahici (de Geer), var. ovis ; (2) Psoroptcs communis (Fiirst), var. 

 ovis ; and (3) Chorioptes communis (Verheyen), var. ovis. 



Of these three the Sarcoptcs cause head scab, the CJiorioptes foot 

 scab, and the Psoroptcs the common scab. 



Salmon and Stiles give a fourth type, FoUicula or Demodectic 

 Scab ; this I have not seen in England, and, anyhow, it is of little 

 importance. 



The foot scab produced by Chorioptes is rare — Zurn wrote upon it 

 in Germany ; it does little harm even when present. 



The Head Scab or " Black Muzzle," due to Sarcoptes, appears on 

 the lips, nostrils, ears, eyelids, and spreads to any part of the body 

 where the wool is scanty. It is easily told from common scab : first, 



* " Journal Land Agents' Society," vol. ii., p. 156-160, May, lOOo. 



C 



