INSECTS IN RELATION TO MAN 4 I 



demic or contagious character, we shall find use for the highest 

 skill of the microscopist, and the best instruments of micro- 

 scopic research. 



" All these investigations are preliminary to the practical 

 part of our subject. What shall the farmer do to protect his 

 crops ? To answer this question, besides the studies just men- 

 tioned, much careful experiment is necessary. All practical 

 methods of fighting the injurious insects must be tried first 

 on a small scale, and under conditions which the experimenter 

 can control completely, and then on the larger scale of actual 

 practice; and these experiments must be repeated under vary- 

 ing circumstances, until we are sure that all chances of mistake 

 or of accidental coincidence are removed. The whole subject 

 of artificial remedies for insect depredations, whether topical 

 applications or special modes of culture, must be gone over 

 critically in this way. So many of the so-called experiments 

 upon which current statements relating to the value of reme- 

 dies and preventives are based, have been made by persons 

 unused to investigation, ignorant of the habits and the trans- 

 formations of the insects treated, without skill or training in 

 the estimation of evidence, and failing to understand the im- 

 portance of verification, that the whole subject is honeycombed 

 with blunders. Popular remedies for insect injuries have, in 

 fact, scarcely more value, as a rule, than popular remedies for 

 disease. 



" Observation, record, generalization, experiment, verifica- 

 tion these are the processes necessary for the mastery of this 

 subject, and they are the principal and ordinary processes of 

 all scientific research." 



The official economic entomologist uses every means to 

 reach the public for whose benefit he works. Bulletins, circu- 

 lars and reports, embodying most serviceable information, are 

 distributed freely where they will do the most good, and timely 

 advice is disseminated through newspapers and agricultural 

 journals. An immense amount of correspondence is carried 

 on with individual seekers for help, and personal influence is 



2.7 



