jl, 60, Bureau of Entomology, U, S. Dept. of Agriculture 



Plate 111. 



Laboratory Methods in the Cotton Boll Weevil Investigations. 



Fig. 5.— Camera stand designed for botli horizontal and vertical work. Fig. 6.— Arrangement 

 \ised in semiring black backgrounds with camera horizontal. Fig. 7.— Chart making with 

 sterenptictin lor projecting image. Fig. 8.— Chart made from negative image projected by 

 electric light through copying camera. (Original.) 



