152 On the TJessian Ply. 



the time in the autumn when the flies have all or nearly 

 all deposited their eggs, it requires further and more ac- 

 curate observation : for if the young plants appear ab've 

 ground before that time, they will be destroyed, and if 

 the wheat be sown very late, the winter destroys the 

 young plants, or at least so far weakens them, that they 

 make a late growth in the S|/nng, and then fall an easy 

 prey to the insect. 



If a number of ingenious persons in different parts of 

 the country could make some experiments expressly to 

 determine this point, it would be doing a very great ser- 

 vice, not only to individuals, but to their country in ge- 

 neral, for I think this period will be found to be nearly 

 the same in every year. The experiments likely to an- 

 swer this purpose, would be to sow a few square yards 

 of ground with wheat every second or third day from the 

 first to the twenty-fifth of September, and note particu- 

 laily the appearance of the insect m each day's sowing, 

 and it might be proper to note the state of the weather 

 between each sowing, &c. 



Then experiments might be made w'ith very little 

 trouble ; they should be repeated in the same place for 

 two or three years successively, and if they were made 

 in a number of different parts of the country, I think they 

 would determine the matter to a certainty ; and that 

 point being clearly ascertained, would in all likelihood, 

 be the means of ensuring to our country annually some 

 millions of bushels of w heat more than, in the present 

 uncertainty of the matter, can be produced. 



Wright stoxvn, Nov, 2^th, 1820. 



The original of which the foregoing is a transcript, 

 was written in the year 1797. ' Upwards of twenty years 

 experience has since convinced me that the last three or 



