INSECTS IN RELATION TO MAN 401 
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 1s 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- 
Nn 
tion—these are the processes necessary for the mastery of thi 
| meat) 
subject, and they are the principal and ordinary processes o 
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 
27 
