20 WEEVIL-RESISTING ADAPTATIONS OF COTTON. 



a secondary. But the function of the two sorts of branches does not 

 always remain as distinct as in the coifee and cacao. A primary 

 branch, like the main stem, never bears any fioAvers ; it produces only 

 leaves and other branches, mostly secondarv. 



Secondary branches, on the other hand, produce normally a flower 

 bud at the axil of each leaf, and this rule holds very generally, except 

 that at the lower part of the plant it sometimes happens that a l)rancli 

 which has the secondarv position functions as a primary; that is, 

 instead of bearing buds and flowers it produces only leaves and sec- 

 ondary branches. In the Kekchi cotton, as grown crowded together 

 in the Indian fields, the primary branches seldom appear, but when 

 more space is allowed and the soil is fertile it is usual for two branches 

 to start from the axil of each of the lower leaA^es, one promptly pro- 

 ducing flowers, the other assisting in the rapid increase of the leaf 

 surface of the plant and of its power to elaborate food. 



Under the ])opular idea that plants draw their food from the 

 ground the possession of branches which bear little or no fruit might 

 be looked upon as an undesirable character, but when we take into 

 consideration the fact that the leaves instead of the roots are the true 

 assimilating organs of the plant it becomes apparent that a variety 

 of cotton wliich develops its lower primary branches may have an 

 advantage in earliness over one which is ol)liged to depend for its 

 foliage upon secondarv or fruit-bearing branches. In the matter of 

 determinate habits of growth these primary brandies are also a fea- 

 ture, because they enable a jjlant to produce a full quota of leaves 

 without unduly increasing the number of fruiting branches and thus 

 continuing to add to the number of superfluous buds. 



The most obvious characteristic of the Kekchi cotton as it grows in 

 our experimental plots is the long basal branches, which often equal 

 or exceed in length the main stem itself. The most prolific branches 

 of the United States varieties are those which come out from the main 

 stem at the height of about a foot, but the bulk of the crop on the 

 Kekchi cotton is borne much closer to the ground. (PI. II, fig. 2.) 

 The long basal branches facilitate the early ripening of a uniform 

 crop of cotton, but they will not be an advantage under all circum- 

 stances; as, for example, in dry regions where the weevil can be held 

 in check by open culture. The necessary exposure of the fallen 

 squares to the full sunlight on hot. dry soil would be interfered with 

 by a plant of low spreading habit and dense foliage. 



EAKI^V lUOJECTION OF SUPERFLUOUS SQI^ARES. 



That the Kekchi cotton has a limited or determinate growth and 

 does not take advantage of the perpetual summer to become a tree or 

 even a large bush is evident from the fact that in the latter part of 



