PROTECTION OF THE BOLLS. 51 



But as the power of effective proliferation declines in the larger 

 buds another factor of protection comes into play. The later the 

 attack of the weevil the greater is the chance that the bud will mature 

 and the flower will open and turn the weevil larva out of its quarters 

 to die. And since buds commonl}^ mature which have been attacked 

 while still young enough to proliferate, it is easy to understand why 

 attacks made in the later stages seem to be effective only in excep- 

 tional instances. 



An element of uncertainty often attaches to the enumeration of 

 weevil injuries because of the difficulty of finding the egg or very 

 young larva^ of the weevil in the squares which have been only 

 recently attacked. This is especially true in small squares wdiere the 

 anthers are still white and of about the same color, size, and general 

 appearance as the eggs. The possible error does not, however, mate- 

 rially affect the result, since it is to be expected that the same propor- 

 tion of bolls will proliferate and the same percentage of weevil 

 larva^ develop as in the squares which are far enough advanced to 

 show definite results. 



PROTECTION OF THE BOLLS. 



If it be true, as already intimated, that the original habit of the 

 wee\il was to attack the boll instead of the bud, the opportunity for 

 the selective development of protective characters of the boll has 

 l)een greater. This suggestion seems to accord with the results, 

 since the boll of the Kekchi cotton has a series of protective characters 

 even more striking and effective than those of the involucre and the 

 bud. 



TERSISTENCE OF FLOWERS. 



As long as the flower remains in place the young boll is thoroughly 

 protected, the weevils having no means of access except by boring 

 through the withering tissues, which seems not to be attempted. In 

 the Kekchi cotton the flower falls only when detached by the swelling 

 of the young boll. This may also be true of other varieties. (See 

 PI. IX.') 



The frequent sequel of proliferation in the bud, as noted above, is 

 the loss of the young boll through lack of pollination. This is espe- 

 cially true in Guatemala, owing to the tendency of the weevil larvae 

 to eat away the style. On one occasion Mr. Kinsler collected from a 

 field of Indian cotton 28 young bolls showing signs of debility. These 

 measured from 18 to 20 mm. in length, most of them about 15 mm. 

 None of the smaller bolls showed signs of weevil injury, but in many 

 of them the ovules were ah-eady shriveling up. A few punctures were 

 found in some of the larger bolls, aiul in some of these proliferation 

 had occurred. The development of the weevil larva> to maturity 



