FOOD 



169 



skin of the horse, that they have been believed by some to be 

 capable of producing mange. This, however, is not correct. 



The Acari reduce the food to powder, and what they do 

 not eat is soiled by their debris. They can easily be seen 

 by placing some of the 

 material on black paper. 

 Fortunately they are them- 

 selves exposed to the 

 attacks of an enemy Psocus 

 pulsatorius and veloce, both 

 of which actively pursue 

 and destroy them, and at 

 the same time do no 

 damage to the food. 



The weevil, Calandra 

 gramma, is a very common 

 pest of grain ; it is most 

 destructive, reducing it to an empty shell. Weevils are 

 generally found in grain which has been kept for some 

 little time. 



The effect on animals partaking of food affected with vege- 



Fig. 



36. — Gamasus fenorum, magnified 

 (Magne aud Baillet). 



Fig. 37.— Small yellow argas, 

 magnified (Magne and Baillet). 



Fig. 38. — Small white argas, 

 magnified (Magne and 

 Baillet). 



table parasites is by no means regular ; they may produce 

 intestinal disturbance, kidney trouble, and even death, but 

 whether it is due to the fungus, or to chemical changes in 

 the grain does not appear clear ; Boucher attributes it to 



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