23 
p. Thus, if the injury to small grain in a township was re¬ 
ted by its assessor as “considerable” (3), to grass as “none” 
, and to corn as “very great” (5), the total damage would stand 
3. 
Lrranging the card reports in the order of these numbers, so 
ained, I had a series running from the lowest total injury 
the highest, and could bring the different parts of this series 
) comparison with respect to the average acreage in each crop 
1887*,—drawn as before from the abstracts of assessors’ reports 
the State Department of Agriculture. 
.’’he series of numbers thus obtained is longer and more variable 
n those presented above, and the tendency of each column is 
always easily detected by simple inspection; on which account 
ave prepared diagrams (pp. 26 to 31), presenting in graphic form 
facts contained in the tables, and upon these diagrams the 
owing discussions are based. 
^he grades of injury represented by the vertical columns of 
se diagrams range, as will be seen, from 0 to 20; and the num- 
s for average acreage per township at the left of the diagrams 
i from below upward. A line crossing a diagram from left to 
at thus indicates increasing grades of injury, while one passing 
ai below upwards indicates an increase in average acreage per 
nship; consequently, if a line passes obliquely upwards and to 
right it shows that increasing injury by chinch bugs went with 
reased acreage; whereas if it passes obliquely downwards and 
the right, it shows a decrease of acreage corresponding to 
reased injury. 
n the following plates the broken lines have been so drawn 
to represent the figures of the tables just mentioned, and lines 
average direction have been added to show at a glance the gen- 
1 significance of the diagrams, and thus to facilitate comparison. 
‘These computations fen *al crops** were not made fov 188G, 
