ILLUSIBATED GUIDE. 35 



The third and last reason is suggested by the fact, 

 that treeless regions are much more exposed than others 

 to the periodic invasions of certain destructive insects, 

 such as grasshoppers, of which the inhabitants of 

 Manitoba have often had to complain. If to this be 

 added the demands of hygiene — that the atmosphere 

 should always contain a certain amount of moisture, 

 and that trees should abound, here and there, in all 

 countries, to serve as filters to purify the air from the 

 quantity of putrid emanations it contains — ^my readers 

 will be convinced that it is absolutely necessary to the 

 well-being of a country abounding in prairies, that a 

 judicious system of tree-planting in fit localities should 

 be immediately put in practice. 



CHAPTER Iir. 



WHAT TREES TO PLANT. 



The necessity of re-planting the wood-lands having 

 been, I hope, demonstrated to your satisfaction, and the 

 dilFerent soils and localities fit for the work described, 

 let us now consider what kinds of trees we ought to 

 select for the purpose. 



It is not advisable to go beyond the indigenous trees, 

 that is, those which grow naturally in the country. It is 

 true that there may be some chance of success with 

 certain kinds of trees which, though not natives here, are 

 indigenous in countries which enjoy almost the same 

 climate as our own. Still, these kinds are few in number, 

 and besides, their use would be experimental, and con- 

 sequently, hazardous ; so that, if they are tried at all, it 

 should be on a small scale, and purely as an experiment. 



But it is far otherwise with our magnificent native 



