82 WEEVIL-RESISTING ADAPTATIONS OF COTTON. 



Page. 



Early planting, discussion . 13 



essential in southern Texas , 12 



Egg puncture sealed by weevil 61 



Eggs of boll weevils, encystation 58, 61 



Egyptian cottons, immunity from bollworm 53 



involucral bracts • 37 



less hairy than Upland varieties 25 



not immune to boll weevil 42 



oil glands 53 



of American origin 9 



precocious in Guatemala 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 



opening, effect on larvae 47, 63 



persistence 51 



position 27 



Foliage, compact, effect on keleps 26 



Food, change, advantage to plants and animals 26 



Fungi, growth in nectaries 30 



Germination, cotton seed in Guatemala „ 15 



Gossypium barbadense, origin 8 



herbaceum, Asia Minor varieties 53 



confusion with G. hirsutum 9 



nectaries 31 



peruvianum, specific validity 67 



Growth, alternating periods in tropical plants 23 



utility of acceleration 55 



Guatemala, central plateau .- 24 



eastern, climate 12 



methods of cotton culture 19, 70 



nature of the country 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 attractive to boll weevil 69 



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



Howard, L. O. , 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 



In breeding of cotton by Indians 15 



Indeterminate varieties unsuited to early destruction of plants 13 



