30 TRANSACTIONS OF THE ILLINOIS 



But, with the gradual " growth of the country," as we call it, 

 there comes a change. The richest soils become exhausted by con- 

 stant cropping, and must be artiticially enriched; soon it is found 

 that tracts, naturally too poor to be profitably cultivated when land 

 and produce were cheap, now that the returns from land and land 

 itself have materially appreciated, will repay inclosing and bringing 

 under the plow. Then this appreciation reaches a point where it 

 pays to reclaim the swamps, and ditches are dug and drains are laid; 

 and where it pays to protect extensive bottom lands against overflow, 

 and then levees are built and river channels are straightened and 

 deepened. In the meantime, costly machinery has come into profit- 

 able use to replace the simple hand implements of the pioneer; and 

 care and skill and thoughtfulness and education and ability of no 

 mean order are finally found necessary to the farmer, if he is to 

 compete successfully with his neighbors, and with his rivals for a 

 market in other lands. 



I have rapidly reviewed this course of events in the development 

 of a new country, with which many of you are personally familiar, 

 because a very similar account might be wrilten of the development 

 of the science and the art of economic entomology. These, too, 

 have had their pioneer age, — a time when the lonely squatter upon a 

 boundless western plain was not more isolated and lonely than the 

 scattered students of insects in their I'elation to agriculture — a time 

 of the boundless fertility of an undisturbed soil, when the happy 

 entomologist could hardly take a morning walk in his garden without 

 having his eyes saluted with some new and important fact respecting 

 the relations of insects to human industries and interests; a time 

 when a first-class microscope was as superfluous for him as a hand- 

 plow for the sod-corn farmer; when a pair of good eyes, a habit of 

 observation, and a capacity for accurate statement were about all the 

 qualifications needed to make one a most useful and productive 

 worker in this department of knowledge. 



Then came the period of rapid extension of culture, if I may 

 so describe it; the time when Harris in Massachusetts, Fitch in New 

 York, Walsh, LeBaron and Thomas in Illinois, and Riley in Missouri, 

 were, with indefatigable activity and distinguished success, extending 

 the boundaries of our knowledge over the larger part of the area of 

 economic entomology; cultivating this area, I will not say super- 

 ficially, but in the somewhat rapid and cursory manner which the 

 very nature of the case and the circumstances of the time rendered 

 not only inevitable but best and most profitable. 



What a long list of insects have been treated, more or less thor- 

 oughly, by these prolific writers, and, nevertheless, how few of even 

 the most destructive of them are yet completely known. How little 

 experimental work of the thorough, intelligent, accurate and exhaus- 

 tive sort which the subject demands, has yet been done. It is evident, 

 i^ short, that while this period of the progressive occupation of the 



