12 



This shows that out of a total of 161 eggs placed on the different 

 parts of the cotton plants, 84, or 52 per cent, were deposited on the 

 leaves. The eggs placed on leaves, leaf stalks, stems, and weeds niu}' 

 be considered in practically the same class with respect to the suscep- 

 tibilit}^ of the resulting larvw to poisons, and the percentage is thus 

 raised from 52 to approximately 73. 



The combined i-esult of the examination of eio-ht cotton plants for 

 boll worm eggs, taken at random in a typical field, is as follows: 



Distribution of boUworm eggs on plants. 

 Eggs found on — 



Leaves 23 



Squares 15 



Flowers 



Leaf stalks (petioles) - 2 



By this method it is shown that approximately 65 per cent of the 

 eggs found on the plants was on other parts than the squares, flowers, 

 and bolls. 



Fig. 5.— Nonnal cotton square at left; flared square at right, due to bolhvorm attack— natural size 



(original). 



Bollworm injurj^ to cotton squares is quite characteristic and is not 

 likely to be confused with that of any other insect, except, possibly, 

 with that of Thedapmas, The injury done by this latter species is, 

 however, comparatively insignificant. The usual effect of bollworm 

 injury on the squares is to cause them to "flare " and to drop (fig. 5). 

 But there are other causes which bring about this '' flaring " and drop- 

 I'ji 



