THE COLORADO BEETLE. 151 



two hundred and nineteen bushels ; the unmannred, one 

 hundred and twenty-six bushels. In 1875, the same plot, 

 manured, produced two hundred and eighty-nine bushels of 

 potatoes : the unmanured, one hundred and twenty-eight. 

 In 1876, the same plot, manured, produced eighty-four bush- 

 els ; the unmanured plot, forty bushels. The unmanured 

 plot had not one table potato upon it. I will say here, in 

 passing, what some other experimenter will deny, perhaps, 

 that in trying these two plots of potatoes, we discovered a 

 remedy for the Colorado potato-beetle. We did not want to 

 try it. The potatoes on the unmanured plot were extremely 

 feeble ; they hardly developed any leaves at all. The weather 

 was dry ; this was the third crop without manure. The plot 

 beside it, that had manure, developed a fine top, and the 

 beetles attacked it, and ate it all up, and not a bug touched 

 the unmanured plot. I suppose the fact to be, that the 

 potato-bug found no tender foliage on the vines of the unma- 

 nured plot, and therefore they attacked the manured plot, 

 and although they were fought vigorously and persistently, 

 they destroyed the foliage in spite of all that we could do. 



The next plot has a lesson in it. It was manured in 1874 

 with a large quantity of chemicals, to see how much corn 

 could be produced on the acre. It yielded one hundred and 

 four bushels of shelled corn. The normal yield that year, as 

 you remember, was thirty-four bushels. The same plot in 

 1875, planted a second time to corn, and unmanured, yielded 

 sixty-four bushels. The same plot was planted in 1876, 

 without any manure, and yet, in this dry season, it has 

 yielded thirty-six bushels. The first year, one hundred and 

 four bushels ; then sixty-four bushels ; then thirty-six bushels 

 this season, with one manuring, and that in 1874. That is 

 the result of the experiment with that crop. 



Mr. Slade. ' How much fertilizer was put on that first 

 year ? 



Prof. Stockbridge. The first year, the amount of fertil- 

 izer put on was to make one hundred bushels to the acre, the 

 thing being done simply to answer this question, without any 

 regard to results, or anything else : "If you can make twenty- 

 five or fifty bushels to the acre, beyond the natural yield, why 



