this period it has developed the most scientific and selective poisons 
possible, Occasionally a few seed-eating birds are killed, but the total 
number is negligible, 
The Biological Survey is a conservation organization and will under- 
take no work that will be detrimental to any species of animal not inter- 
fering too greatly with the interests of man. Those conversant with actual 
conditions in the range States realize that if agriculture is to survive, 
the control of injurious rodents is as essential as is control of the corn 
borer, the chinch bug, the boll weevil, the grasshopper, the coddling moth, 
and numerous other insects that become agricultural pests. The Survey 
insists that in conducting work of this sort, the most careful supervision 
by trained technicians must be given, All cooperating agencies recognize 
the necessity for such supervision, and as @ result a most worth—while 
program has been carried on during the past three years. 
aie 
