24 PROLIFERATION IN CONTROL OF BOLL WEEVIL. 



Studying Table YII with a view to makino; a comparison of the 

 varieties in regard to their tendency to prohferate in response to egg 

 punctures and hirval injuries, it appears that, in cases where one hun- 

 dred or more observations were made, the highest j^ercentage showing 

 proHferation was 67.7 per cent, found in Allen at Calvert, Tex., on 

 September 11, 1905. A previous examination of this variety shows, 

 however, only 50.4 per cent, which is almost exactly the average per- 

 centage found for all varieties. The average of all observations on 

 Allen shows 59.3 per cent having proliferation. The lowest ])ercentage, 

 from observations which are closely comparable, was 33.9 ])er cent, 

 found in Sunflower at Victoria, Tex., in 1904. Unfortunately there 

 are no other observations upon Sunflower by which this result may be 

 checked to see w^hether it may be considered as a somewhat constant 

 tendency in that variety. This being true, it would not be safe to 

 conclude that Sunflower shows the least tendency to proliferate among 

 the varieties examined. It should be noted that the average of the 

 tliree Egyptian varieties grown at Victoria in 1904 is 52.3 per cent, 

 which is slightly a])ove the general average for all varieties examined. 

 Considering all examinations for each of the four varieties having 

 more than 500 observations each, we find for King 53.2 per cent, for 

 Territory 52.8 per cent, for Shine 49.7 per cent, and for Native 45.7 

 per cent. Because of the larger number of observations made the 

 average percentages shown for these four varieties are undoubtedly 

 the most reliable of all those given in the table. It appears to the 

 writer from the small variation of 7.5 per cent that the tendency of 

 difi'erent varieties to proliferate in response to weevil injury by ovi- 

 position or by larval feeding is a remarkably uniform character. 

 Much more extensive examinations would be required to determine 

 the positive status of so many varieties in respect to this tendency to 

 proliferate. 



SUMMARY OF RECORDS FOR FOUR VARIETIES. 



Examining more closely the portion of Table VII relating to 

 mortality, we find that the percentage of mortality in squares with 

 proliferation ranges from to 50 per cent. The latter figure is found 

 in Triumph at Calvert, August 25, 1905. A general average for the 

 4,121 scpiares examined is 22.3 per cent. For the four varieties — 

 Territory, King, Shine, and Native — a closer comparison can be made 

 by presenting the figures in tabular form. 



