476 BACTERIAL DISEASES OF PLANTS 



20. Comparative studies of Aplanobacter species. 



21. Old world distribution of Stewart's disease of maize. 



22. Methods of distribution of parasitic species on seeds, rhi- 

 zomes, tubers, corms and bulbs. Responsibility of the seedsman. 



23. Distribution of bacterial parasites on nursery stock. 

 Responsibility of the nurserymen and dealer. 



24. Insect and other animal distributors of diseases and their 

 control. "Bacillus carriers" among insects. Man's responsibility. 



25. The flora of rotting potato tubers — in the advancing 

 margin of the rot and in remoter parts. 



26. The saprophytic flora following each parasitic disease. 



27. Occurrence of black chaff of wheat in Europe, Asia 

 and South Africa. 



28. Occurrence of bacterial barley blight in Europe and Asia. 



29. Occurrence of Elliott's oat blights in Europe and Asia. 



30. Symbiotic diseases: Ardisias, Pavettas, etc. 



31. Favoring organisms — bacterial, fungus, protozoan. 



32. Antagonistic soil organisms. 



33. Cause of tobacco mosaic and other mosaic diseases. 



34. Nature of the sugar-cane disease in Brazil. 



35. Nature of the sugar-cane disease in Argentina. 



36. Nature of the East Indian cane-disease known as Sereh. 



37. Nature of the serious Porto Rican stripe-disease of sugar 

 cane. This occurs also in Java and Hawaii. One should plant 

 sound cane and avoid rattoon crops. Insects spread it. 



38. Nature of the destructive sugar cane disease of Fiji. 

 (H. L. Lyons, Hawaiian Planters Record, Vol. Ill, July, 1910, 

 p. 200 and F. Muir, Ibid., p. 186). This causes tumors in stems 

 and leaves. 



39. Nature of the bark disease of rubber (Petch: Physiol, 

 and Diseases of Hevea brasiliensis, London, 1911, PI. IX). 



40. Nature of Janse's disease of Erythrina trees in Java. 



41. Cultural characters of the bacterial organism causing 

 tumors on the Aleppo pine and on other European pines. 



42. Cause of peach yellows. Is it a leptome disease? 



43. Cause of peach rosette and of pecan rosette. Are they 

 mosaic diseases? Are they denitrification diseases? 



44. Cause and control of bud-rot of the coconut. 



45. Correlation of tobacco leaf spots. How many are there? 



