32 



JOURNAL OF ECONOMIC ENTOMOLOGY 



[Vol. 8 



half dozen years the possibilit}^ that an5d;hing but arsenic could be used 

 does not seem to have occurred to most workers. The work of Max- 

 well-Lefroy along this line in India deserves mention here because of 

 its pioneer nature. 



When on the same da}^ two peach orchards, one in Northern Ohio 

 and the other in Virginia, are sprayed with the same material at the 

 same strength, and apparently under practically the same conditions, 

 and one orchard is severely injured while the other escapes, it is time 

 for a critical study of all the factors concerned in spraying. 



And here I must make a statemicnt which will seem very academic in 

 its nature. In research experim.entation in almost every case a large 

 number of factors are involved. Frequently these are light, tempera- 

 ture, humidity, composition and variations in composition of the 

 material used, time of year, etc. If we are to obtain positive and con- 

 clusive results from our experiments we must take into account every 

 factor which may possibly be concerned, and run a series of experi- 

 ments in which only one factor shall vary, the others remaining fixed. 

 This, of course, means a complete series for each factor involved, in 

 combination with every variation of every other factor. Such experi- 

 ments take time — often many years — ^to produce complete results, but 

 the necessity for conducting them in this way if the conclusions reached 

 are to be relied upon, should be self-evident. Yet a careful analysis 

 of many of the experiments, the results of which have been published 

 during the last decade, shows that in some cases three, four or even 

 more of the factors which might influence the results have been allowed 

 to vary at the same tim.e. Under such conditions as these I claim that 

 the principle just advanced, even though acknowledgedly academic, 

 is being so largely ignored that attention should be called to it, and that 

 work done without due care should receive only such fractional credit 

 as it deserves, without acceptance as a final dictum. 



Some of those present today listened last year to a magnificent 

 presentation of the methods used in the investigation of pellagra in 

 the South. Several afterwards remarked that such thoroughly S3^s- 

 tematized and comprehensive studies could only be carried out with 

 the resources and staff which the Government alone could supply. 

 But if this should be true (and I doubt it), this is no reason why such 

 work as is attempted should not be prosecuted in accord with the 

 simplest principles of inductive logic, as far as it goes, resulting at 

 least in reliable records of the ground actualty covered. 



The '^bug versus bug" doctrine which has been so actively promul- 

 gated in various parts of the country is a most attractive one. It ap- 

 peals to the legislator, to the farmer, and to the business man as a 

 jiatural and logical method for the control of our increasing insect 



