86 



24 hours. Assimilation, therefore, must be very rapid. It is evident 

 that while leaves will sustain life certain nutritive elements found 

 only in squares are essential in the production of eggs. 



Upon dissecting weevils just taken from hibernation it was found 

 that females contained no developed eggs, but that their ovaries were 

 in an inactive condition, similar to those of females which had fed for 

 months entirely upon leaves during the previous fall. Upon examin- 

 ing females taken from seppa cotton later in the spring, but before 

 squares had appeared, it was found that they also were in similar 

 condition. This was also true of females kept in the laboratory from 

 the time of emergence from hibernation until squares became abund- 

 ant, with only leaves for food. It seems peculiar that upon a purely 

 leaf diet eggs are not developed, but all observations made indicate 

 that this is the case. It can not be said definitely whether the females 

 examined had been fertilized, but it is certain that they were not 

 ready to deposit eggs. 



PROGRESS OF INFESTATION IN FIELDS. 



From among the many notes made upon this point the results of 

 the study of two fields are here presented. The first field, consisting 

 of about 15 acres, had l)een jilanted in cotton for several years and 

 was closely surrounded by other cotton fields. The second field of 

 35 acres was upon newly broken land and situated in a comparatively 

 isolated location. 



Examinations were made frequently to determine approximately the 

 percentage of infested squares present in various parts of these fields. 

 The conditions of the examinations were made as uniform as was 

 possible. The fields were divided into blocks, and practically the 

 same ground was covered in each block upon succeeding examinations. 



Table XXII. — Progress of infestation, field 1. 



The observations made in Block I cover a longer period, and are, 

 therefore, more suggestive than those made in Block II. Evidently 

 infestation began with the first appearance of squares. So long as 

 the hibernated weevils alone were at work the percentage did not 

 increase very rapidly, but with the advent of the second generation 



