PRACTICAL PAPERS—COLORADO POTATO BUG. 327 
nois, in many separate columns, just as Sherman marched to 
the sea, the southern columns of the grand army lagged far 
behind the northern columns.” 
Now, let us see how far the predictions above have been 
verified. By the autumn of 1866 the Colorado potato bug, 
which appears to have invaded the southwest corner of Wis¬ 
consin at as early a date as 1862, had already occupied and 
possessed a large part of the cultivated or southern parts of 
that state ; and in Illinois, if we draw a straight line to con¬ 
nect Chicago with St. Louis, nearly all the region that lies to 
Fiy. 44. 
Colors — (<Z) deep orange; (b and c ) Venetian red, inclining to cream color; (d and e) cream 
con,r and black. 
the northwest of that line was overrun by it. It subsequently 
invaded parts of south Illinois, occurring in Union, Marion 
and Effingham counties in 1868; and already, in 1867, it had 
passed through the eastern borders of north and central Illi¬ 
nois into western Indiana and the southwest corner of Michi¬ 
gan , and 'finally, in 1868, it had reached Danville, Indiana, a 
point which lies nearly in the centre of that state, as we 
learned some time ago from Mr. A. Furnas of that city; and 
the agricultural papers have since recorded its appearance in 
Marion county, which lies in the geographical centre of the 
state. Thus it appears that its average annual progress toward 
