100 PRIZE essay: 



lowing August ? Every one knows that it is not possible, in 

 ploughing, to turn a sod or furrow slice completely over, so that 

 all parts shall be altogether reversed. The furrow slices may be 

 made to lie with great compactness, but there will be instertitial 

 spaces into which the pupa may fall or wriggle themselves, and 

 eventually escape. When the field is ploughed immediately 

 after harvest, not only will the autumnal rains fill the spaces be- 

 neath and between the furrow slices by washing down fine parti- 

 cles of earth, but the influence of the many months of winter 

 and spring will consolidate the furrow slices, and their compact- 

 ness may be ensured by rolling in May or the early part of 

 June, before the fly appears. 



163(d). Kolling the land immediately after ploughing is ac- 

 complished, will give further security to the prison in which the 

 pupa are enclosed by this simple artifice. 



lG3(e). "We may now consider the feasibility and adaptation 

 of this artifice of after harvest ploughing and rolling, to those 

 sections of Canada where the fly has not yet appeared. The 

 country about Lake Simcoe has not yet apparently suffered from 

 the depredations of this insect, and we know that the districts 

 between London and the Detroit River are now only threatened 

 at their borders with the invasion of the wheat midge. The 

 question proposed is, what ought the farmers of these favored 

 districts to do in order to avoid the slow but sure progress of 

 the devastator. 



163(f). Every one will say, first banish the idea from your 

 minds that you are safe from an invasion ; let the experience of 

 half a continent foreshadow the contingencies of a few town- 

 ships. Acknowledging, then, the necessity of preparing for the 

 invasion, what is to be done ? The answer depends upon the 

 presence or absence of another insect. 1st. Are you liable to 

 the attacks of the Hessian fly? No; then sow early, &c., &c. 



