MICHIGAN ACADEMY OF SCIENCE. 275 



TABLE OF CONTENTS. 



I. Introduction. 



II. Historical. 



Ill, Economic Importance. 



IV. Distribution. 



V. Signs of the Disease. 



1. On leaves. 



2. On petioles. 



VI. Etiology. 

 VII. Description of Causal Organism. 



1. Spores. 



2. Conidiophores. 



3. Mycelium. 



VIII. Infection Phenomena. 



1. How fungus enters host. 



2. Infection experiments. 



a. With young and old leaves. 



b. Stem and petiole, 

 e. Floral and seed. . 



3. Humidity and infection. 



4. Relation of light to infection.- 



IX. Inoculation Upon Other Hosts. 



X. The Host in Disease. 



1. Morbid anatomy. 



2. Morbid physiology. 



XI. Physiological Relations of the Causal Organism. 



1. Germination studies. 



a. Spore formation. 



2. Cultural studies. 



3. Metabolism. 



a. Changes in nitrogenous media. 



b. Changes in carbohydrate media. 



c. Anaerobic growth. 



4. Temperature relations. 



a. Thermal death point. 



b. Effect of dry heat. 



c. Thermal death point of germinated spores. 



5. Relation of .humidity to germination. 



6. Resistance to desiccation. 



