INSECTICIDES AND GENERAL REMEDIES. 417 



is perhaps necessary in order to protect our fruits, our field crops, or 

 our game-preserves ; but on the other hand, the preservation of certain 

 kinds of benelicial birds should be rigidly enforced. The question of 

 interfering with the "balance of Nature " is always a serious problem, 

 and great caution, combined with intelligent forethought, should be 

 exercised. On the one hand we get certain animals preserved by 

 killing their natural enemies, but on the other hand we may have a 

 direful pest unexpectedly assert itself as the result of killing natural 

 enemies. 



Beferenres to Liferatui'e consulted. 



IJoard of Agriculture Leaflets, &c. 



Collinge, Walter E. Reports on Injurious Insects, &c. 



Theobald, Fred. V. A Text-Book of Agricultural Zoology. Chiefly chapter 

 on the prevention and destruction of insect pests. 



2 u 



