CAUSES AMI) CONDITIONS OF BCD I'Kol-I FKIIA'IION. 49 



fre({iient than that ol" the staiuiiial tiilx-. is probably also k'ss cH'ect- 

 ive, since the weevil larva' could escape before it into the center of 

 the flower while the proliferation from the staniinal tube ^rows 

 outward, as though to meet the intruder and keep him separated 

 from ^he nu)re s))ecial ()r<»;ans. 



The habit of the larvie to seek tlie center of the biul and gnaw 

 off the style is responsii)le for the loss of large numbei's of younger 

 bolls which have sutfered no direct injury from the weevil. Even 

 though the larva be subsequently killed by proliferation or though 

 the flower drops oti' and carries the larva with it, the lack of polli- 

 nation must prevent the development of the young boll unless par- 

 thenogenesis takes place, which seems improbable. 



Larva' were foinid in several instances in nearl}- full-sized buds 

 about to oj)('n. and in another case a more than half-grown larva 

 was found inside the central colunni of an open flower. More or less 

 distorted flowers with unmistakable signs of previous proliferation 

 in the bud stages are commonly found in the Kekchi cotton fields. 



Summarizing the results of the study of proliferation in the 

 Kekchi cotton, it nuiy be said that although the frequency of pro- 

 liferation in the young scpmres is very great, its eflicienc}^ in prev^ent- 

 ing the breeding of the weevils is somewhat less than might be ex- 

 j)ected in Texas, owing to the difference of food habits among the 

 weevils. If the Texas weevils are as consistent in their habits as 

 now suj)[)osed, the introduction of the Kekchi cotton or of a similar 

 proliferating variety might be of gi'eat benefit as a preventive 

 measure. The extent, however, to which it could be made to compass 

 the complete destruction of the weevil would depend somewhat upon 

 the degree, if any, to which they might i-eturn to the habit shown in 

 Guatemala of feeding upon the ovaries or boll I'udiments rather 

 than upon the j)ollen of the young buds, an important and hitherto 

 unsusjiected difference in habits between the weevils of Texas and 

 those of Guatemala. 



CAUSES AND CONDITIONS OF BUD PROLIFERATION. 



That the proliferation is occasioned by the injuries of the weevil is 

 too obvious to admit (jf doubt, but it may be of much practical 

 imj^ortance to learn the exact way in which the new growth of tissue 

 is brought about. The disturbing factor might be either mechanical 

 or chemical. The new growth may be a direct response to injury of 

 the weevils in feeding or laying eggs, or it might be stinudated indi- 

 rectly by the secretions of the young larva, or by chemical changes 

 or decay of the danuiged tissue. A second mechanical possibility is 

 that of pressui'c developed in the young and rapidly growing bud. 



liDtrJ— No. ««— u.j M i 



