CONTENTS 



PAGE 



Introductory 77 



I. A foot-rot of wheat and its causal fungus: 



Symptoms 78 



Fungi present 78 



Growth of the causal fungus on various media 79 



Various agars as media 80 



Summary concerning growth on agars 85 



Rice and similar substances as media, with special note of color phenomena 86 



Summary concerning growth on rice and similar substances 88 



Miscellaneous vegetable media 88 



Summary concerning the foregoing vegetable media 90 



Cereal shoots grown from aseptic seeds as media 90 



Environmental factors which induce variation 91 



Quantity of nutriment 91 



Inhibitory influences . . 93 



Humidity of media 93 



Humidity of air > 94 



Temperature relations 98 



Light 99 



Carbohydrates 100 



Nutrients as affecting conidial length, septation, and shape 101 



Summary concerning environmental factors which induce variation . . . 102 



Morphology of the foot-rot fungus 103 



Mycelium 105 



Senescence phenomena of aerial mycelium 107 



Conidiophores 109 



Conidia 110 



Etiology of foot-rot: 



Evidences of etiological relation of H. No. 1 124 



Constant presence of the pathogene 124 



Absence of other constant parasites 124 



Identity of pathogene proved by culture 124 



Evidence of infectiousness 124 



Conidia produced in moist-chamber culture 125 



Evidence from inoculation 125 



Recovery of organism 128 



Infection phenomena on wheat 128 



Susceptibility of various hosts to infection 137 



Summary concerning etiology of foot-rot 139 



