11 



that this process of mutual cancellation must have reduced them 

 practically to nothing, with the exception of certain geographical 

 differences to be noticed when that plate is discussed. 



Because of the unavoidable variations thus arising, I have made 

 no use, in my discussions, of averages drawn from groups of less 

 than five towns each, — a limit which excludes the more violent, 

 accidental, and miscellaneous fluctuations, but which still leaves 

 some of considerable importance. 



Further, it is to be noted that the terms used in the township 

 reports of injury are not uniformly graded, the gradations being 

 much closer for the lower degrees of damage than for the higher. 

 The destruction of half a crop would doubtless be called a "great" 

 loss, if not a "very great" one, so that the first fifty per cent, of 

 injury is divided by my scale of expressions into four or five de- 

 grees, and the last fifty per cent, into only two or three. 



I have also to' notice that it was usually quite impossible to 

 distinguish accurately the amount of damage done by chinch bugs 

 from that due to drouth, and it is probable that many of the 

 severest cases of damage were really due to drouth and insects 

 combined. 



Finally, I beg to remind the reader that the facts here pre- 

 sented are derived from more than eight hundred men widely 

 scattered throughout the State, each peculiarly competent to 

 observe and report the data for his own district; and that the evi- 

 dence thus accumulated far outweighs that on which any one man 

 or any entire neighborhood can rest an opinion, — amounts to many 

 times more, indeed, than all that has been previously reported on 

 this topic. I believe that I am asking no more than -is deserved by 

 the tedious labor whose outcome is here presented, when I claim that 

 this mass of testimony should be considered as decisive wherever 

 its indications are positive and manifest. 



INJURY TO CORN AS COMPARED WITH ACREAGE IN WHEAT AND OTHER 



GRAINS. 



Table I. 



Southern Illinois, 191 Towns. Injury to Corn, 1887, compared 

 with Crop Areas for the Same Year. 



Degren of Injury. 



No. 

 of Tps. 



Wheat. 



Barle}'. 



Rye. 



Oats. 



Grass. 



None 



Little 



Moderate 



Considerable 



Great 



Very <?reat 



Nearly complete 

 Complete 



1,784 

 3,974 

 1,600 

 1,905 

 3, 289 

 2,278 

 2,945 

 4,266 



1,093 

 1,872 

 245 

 1,114 

 1,521 

 1,375' 

 2,104 

 2, 671 



1,811 

 2,876 

 800 

 2, 419 

 3,057 

 2,391 

 2,859 

 3,157 



2,462 

 1,640 

 210 

 2,121 

 2,805 

 2,616 

 3,152 

 2,975 



