SEASONAL HISTORY. 



71 



burg, Miss. The curve obtained for Victoria is the widest which 

 can be obtained in the United States with the exception of Texas 

 points to the south of Victoria. It is interesting, however, that 



Fig. 12.— Diagram illustrating temperature control of developmental period of the boll weevil. 



(Original.) 



MAX. APR. M<4V *JUM£- UUiy AUG. jgHgT OCT. /VOX Q£TC. 



Fig. 13. — Diagram illustrating normal developmental period of boll weevil in squares, by mouths, at 

 Victoria, Tex., Ardmore, Okla., and Vicksburg, Miss. (Original. > 



Pensacola, Fla., would show almost as wide a curve, but there the 

 weevil would show less rapid development in the hottest months. 

 The Memphis, Tenn., curve is slightly wider than that for Ardmore, 

 Okla., and Dallas corresponds almost exactly with Vicksburg. It is 



