B. r. I. — 180. 



WEEVIL-RESISTING ADAPTATIONS OF THE 

 . COTTON PLANT. 



INTRODUCTION. 



The fact that Central American varieties of cotton have developed 

 weevil-resisting adaptations has alread^y received preliminary notice." 

 A third visit to Guatemala, in the spring of 1905, has given opportu- 

 nity for further studies of the protective characters of the native 

 varieties and for comparing them with the types of cotton now cul- 

 tivated in the United States. For this purpose plantings of Upland 

 and Sea Island varieties have been made in Guatemala, and as the 

 season advanced other tests of the Guatemalan and United States 

 varieties Avere arranged under very ditl'erent climatic conditions in 

 Texas and at Washington, 



These opportunities of comparative observation have revealed a 

 series of protective adaptations of such number and nicety as to fur- 

 nish a unicpie and well-nigh incredible instance of selective develop- 

 ment. The statement of the former paper may be repeated with 

 emphasis, that the presence of the weevil-eating kelep has enabled 

 the Indians of eastern Guatemala to maintain since very ancient 

 times field culture of cotton in the presence of the weevils, with the 

 result that there has been developed a dwarf, annual, short-season 

 variety with numerous features Avhicli, in the absence of sufficient 

 numbers of keleps, afford material assistance in protecting the crop 

 against the ravages of the weevil. 



IMiether this Guatemalan cotton can be made of direct use in the 

 United States or not, it demonstrates the existence in the cotton 

 plant of weevil-resisting characters. The new variety has lint of 

 good length and (piality, so that its utilization in the United States 

 depends upon its adaptal)ility to our climate and methods of culture. 



As already explained in publications devoted to the kelep, the 

 Aveevil-eating propensities of that insect were discovered in 190-1 

 during a visit to Guatemala which had been undertaken in the hope 

 of finding a weevil-resisting variety of cotton. It had beei\observed 



« Cotton Culture in Guatemala. Yearbook of the Friited States Department of 

 Agriculture for 1904, 475-488 ; Science, N. S., 20 : 6G6-G70, November IS. 1904. 



7 



