276 NINETEENTH REPORT. 



7. Light relations. 



8. Experiments dealing with toxic substance produced by the 



fungus. 



a. Historical introduction. 



b. Test of metabolic by-products. 



c. The nature of the toxic substance. 



XII. Methods of Dissemination. 



1. Dissemination and rainfall. 



2. Wind dissemination of spores. 



XIII. Control. 



XIV. Summary. 



XV. Literature Cited. 

 Appendix. 

 Plates. 



