IN REFERENCE TO AGRICULTURE. 139 



(83.) The pursuits of the agriculturist and of the 

 planter bring them more immediately into contact 

 with the productions of nature ; and hence they 

 are more especially interested in understanding their 

 qualities. It is not only necessary to be well ac- 

 quainted with the different vegetables grown or 

 reared for economic purposes, but to understand 

 the cause of the injuries they are subject to ; and 

 then to devise efficient remedies for those injuries. 

 Here, also, is a wide field open for improvement 

 and for discovery, and in which no information is 

 so practically useful as that afforded by natural 

 history. We are continually hearing of the failure 

 of crops, and of attendant ruin. Now, in nine 

 instances out of ten, these devastations have origin- 

 ated in the unusual abundance of some particular 

 insect, which, from unknown causes, has appeared 

 in great numbers. We contend not that the know- 

 ledge or the ingenuity of man could foresee such 

 evils, or could totally counteract them ; but expe- 

 rience has shown how much may be done, in many 

 cases, both in the way of prevention and of cure. 

 To do this effectually, however, recourse must be 

 had to natural history. The cause of the injury 

 being ascertained, the habits of the insect must be 

 studied in all its different stages. What will prove 

 more or less efficacious in one of these stages, will 

 be totally useless, or will increase the evil, in another. 

 Hence arises the necessity of ascertaining names 

 and species; without which, no effectual steps can be 

 taken. 



(84.) If there required any striking fact to 



