82 WEEVIL-KESISTING ADAPTATIONS OF COTTON. 



Paga 



Early planting, discussion 13 



essential in southern Texas 12 



Egg puncture sealed Ijv weevil 61 



Eggs of boll weevils, encystation 58, 61 



Egyptian cottons, immunity from boll worm 53 



involucral bracts ,37 



less hairy than Upland varieties 25 



not immune to boll weevil 42 



oil glands 53 



of xlmerican origin 9 



precocious in (jruatemala 17 



preference of weevils 26 



proliferation 50 



susceptibility to injury 42 



Environment not actuating cause of evolutionary change 68 



Evolution, illustration of influence of natural selection 71 



Evolutionary origin of external nectaries 31 



Fertilization, discussion . . .■ '52 



prevention by rain 21 



Field cultures, failure in plateau region of Guatemala 25 



Flower bud, position 20 



Flowering period, short 23 



Flowers, failure of pollination 51 



keleps imprisoned 29 



of Kekchi cotton, color 54 



Kidney cotton, color 53 



Oldening, effect on larvte 47, 63 



persistence 51 



position 27 



Foliage, compact, effect on keleps 26 



Food, change, advantage to jjlants and animals 26 



Fungi, growth in nectaries 30 



Germination, cotton seed in Guatemala 15 



Gossypium burhadense, origin ' 8 



herhaceinn, Asia Minor varieties 53 



confusion with G. hirsutum 9 



nectaries 31 



X>eruvianum, specific validity 67 



Growth, alternating periods in tropical plants 23 



utility of acceleration 55 



Guatemala, central jilateau 24 



eastern, climate 12 



methods of cotton culture 19, 70 



nature of the countrj^ 15 



field experiments 34 



importation of foreign thread 24 



Indian methods of cultivation 12 



western , cotton 25, 70 



Guatemalan conditions, effect on United States varieties 17 



cottons, preference of keleps 25 



Hairs, cotton plant, assistance to keleps 25 



Hairy Guatemalan varieties of cotton 25 



stalks and leaf stems of cotton 25 



Heredity, mechanism 68 



Hibiscus, involucral appendages of species 33 



nectaries of species 32 



species not attractiv^e to boll weevil 69 



Hinds, W. E., observations 25, 42, 43, 44, 55, 61, 62, 64 



Howard, L. 0. , observations ; 45 



Humid districts, behavior of cotton 43, 44 



Hunter, W. D., observations 14, 25, 42, 43, 44, 48, 55, 61, 64, 76 



Immunity of buds and bolls, periods _ 74, 75 



Inbreeding of cotton by Indians 15 



Indeterminate varieties unsuited to early destruction of plants 13 



