INTRODUCTION. 
XXXI 
Boll Worm, while Dr. Anderson and Judge Job n sou represented the 
Commission in their respective parts of the same State, making experi- 
ments themselves and also assisting Professor Jones. Mr. Roane was 
located for some time at Selina, Ala., making extracts and decoctions 
of various native plants in that region, while Judge Bailey represented 
the Commission in the cane-brake region of the same State, and was 
more particularly charged with what pertains to the food habits and 
hibernation of the parent moth. In Georgia Professor Willet made a 
series of experiments to test the value of fungus germs iu the destruc- 
tion of the worm. Professor Smith, of Tuscaloosa, Ala., was engaged 
in the work on the cotton belt, represented in Chapter VI. Prof. J. P. 
Stelle, of Mobile, Ala., spent nearly live months in Texas, traveling 
from place to place, under special instructions as to observatious, while 
Mr. Pat ton, in addition to assisting iu the office work, spent part of 
the summer at Selma, Ala. Here, also, Mr. Sehwarz was stationed, as 
we found it convenient to make this point a sort of field headquarters 
for the work, especially the testing of remedies and remedial appliances. 
Mr. Hnbbard was stationed in Florida, principally at Centreville and 
Crescent City. Dr. Barnard had his headquarters at Vidalia, La., in 
tin* early part of tin 1 season, making notes in portions of Louisiana and 
Mississippi, but later in the season joined the force at Selma, where he 
gave more particular attention to the machinery experimented with. 
Whatever time could well be spared from the ollice work of the Commis- 
sion we devoted to field work, visiting (lining the months of July, 
August, September, and October the different agents, and personally 
aiding and suggesting in the carrying out of plans and instructions. 
These instructions were given in special correspondence with the 
agents, as also iu Circular No. 7, and in the following supplementary 
circular letter : 
SUPPLEMENTARY INSTRUCTIONS TO AGENTS. 
Ol KICK OF THE U. S. ENTOMOLOGICAL COMMISSION, 
No. 1700 V.Uh Street, Washington, D. C, July 80, 1880. 
In addition to instructions already transmitted to you, I hereby call your atten- 
tion to a few important points which should have especial attention. 
In the application of poisons already known to be effectual the great desideratum 
is to ascertain the minimum quantity that can be used successfully. It is my inten- 
tion to perfect appliauces that will throw either an extremely fine mist or an almost 
impalpable cloud of dust from near the ground up among the plants and on the under 
side of the leaves. 
Test, therefore, thoroughly, by a series of experiments, whether: 
1. London purple, Paris green, or arsenic can be used without diluents by forcing 
them dry in minimum quantity, onto the plants, and ascertaining how much ground 
a pound of each may be made to cover. 
2. If they cannot be used without diluents, the minimum quantity of such diluents 
necessary. 
3. How far, by fine spraying, and economy in preventing wastage on the ground, 
the number of gallons of water to a pound of these materials may be reduced — the 
