18 BULLETIN 245, TJ. S. DEPARTMENT OF AGRICULTURE. 



DISCUSSION OF DIAGRAM (FIG. 1). 



From the results of some open-pile experiments at New Orleans the 

 comparative cost and larvicidal efficiency of some of the more favor- 



/oo 



able substances have been computed and are shown graphically in 

 figure 1. Most of these calculations are based on an average of but 



