80 WEEVIL-RESISTING ADAPTATIONS OF COTTON. 



Boll weevils — Continued. Page. 



bacterial diseases following injuries 62 



behavior in absence of keleps i 24 



on foot 25 



within bolls 59 



best conditions for perpetuation 70 



change of habits 63 



destruction by chickens and turkeys 24 



determination of life cycle in bolls and squares 64 



development of pollen-eating habit 63 



diverse habits of males and females 27 



diversity in size 64 



effect on unprotected cotton field 35 



under favorable conditions 69 



eggs, fate .... 58 



exclusion from large bolls . . 59 



feeding in bolls 61 



general effect on cotton plants 10 



in fields cultivated by Indians 35 



injuries in Guatemala 47 



injurious nature unknown to Indians 71 



mortality in spring 14 



not attracted by nearest relatives of cotton 69 



pollen diet 55 



preference for upper portion of plant 27 



selective influence 10 



self-destruction 34 



short-season varieties of cotton for control 22 



starvation 12, 14 



Bolls, diseases from superfluous nectar 28 



efficiency of adaptive characters 61 



fed upon by boll weevils 61 



feeding punctures 61 



infestation by weevils 55 



injured, discoloration 56, 59, 62 



Kekchi cotton, description 16 



immunity 56 



linings of chambers, toughness as protection from boll weevil 56 



normal, absence at Rabinal, Guatemala 24 



oil glands 53 



outer walls, proliferation 58 



variation in thickness 56 



pendent, discussion 27 



periods of immunity 74, 75 



position 27 



proliferation 59 



in relation to that of buds 64 



protection 51 



unconscious selection for uniform ripening 11 



very young, immunity 52 



weevil punctures 61 



weevil-proof lining 57 



young, rapid growth 55 



Bractlets of involucre 33 



Bracts, appressed margins 38 



dimensions 40 



flaring 40 



involucral, grown together 37 



hairy margins , 41 



lacinia? 43 



of Kekchi cotton . 16 



protective feature of large size 39 



Branches, long basal, disadvantages of v 20 



of Kekchi cotton 19 



of cotton, compared with those of other plants . . 19 



dimorphic , 19 



