70 



as a lure to May-beetles about to lay their eggs is unmistakable here, 

 and much more emphatic than that obtained from our general col- 

 lections behind the plow. This is, indeed, what we should expect, as 

 any actual preference of one crop over another would be much more 

 plainly manifest when extraordinary numbers of May-beetles were 

 abroad than when we were dealing with a sparse and widely scat- 

 tered population. 



