LIST OF ILLUSTRATIONS 



Frontispiece: Prof. Thomas J. Burrill discoverer of the first bacterial disease of 



plants (pear blight). Photograph in 1884 (at 45), handwriting in 



1915 (at 76). 



Page 



1. Savastano, Cavara, Wakker, Arthur, and Waite. Photographs of early 

 workers on bacterial diseases of plants. All except of Savastano are of 



the period when they made their first investigations 2 



2. Mango fruit-cluster attacked by Doidge's bacterial spot disease 3 



3. Bacterial leaf-spot of mango from South Africa. >2 nat. size 9 



4. Coconut bud-rot of the West Indies 9 



5. Cross-section of a banana fruit-stalk attacked by Rorer's disease 11 



6. Angular leaf-spot of cucumber due to Bacterium lachrymans Smith 



and Bryan 14 



7. Cucumber stem showing white film and cracks due to Bacterium 



lachrymans 14 



8. Gelatin stab culture of Bacterium lachryma'hs 15 



9. Small gelatin colony of Bacterium lachrymans for marginal appearance. 15 

 10, 11. Recovery of tomatoes from an attack of Bacterium solanacearum EFS 18 



12. Head of wheat showing bacterial black chaff disease (Kansas, 1915). ... 19 



13. Agar poured plate colony of black chaff bacterium (Bacterium trans- 



lucens var. undulosum Smith, Jones and Reddy). No. 273, Nebraska. 20 



14. Stalk- and glume-striping in black chaff of wheat. No. 268, Kansas. . . 22 



15. Bacterial exudate from glumes in black chaff of wheat. A natural 



infection on Montana spring wheat 23 



16. Black chaff of wheat, showing a pure culture glume-infection done with 



No. 20 24 



17. Black chaff of wheat, showing ordinary appearance of the yellow colonies 



on agar plates. No. 20, McKinney, Texas 26 



18. Black chaff of wheat, showing internal markings of surface colonies on 



agar. No. 662 from Monticello, Illinois 27 



19. Same as fig. 18 but^No. 678 from El Reno, Oklahoma 28 



20. Black chaff of wheat : gelatin colonies of Bact. translucens var. undulosum, 



showing dry liquefaction pit. No. 252 from Republic, Missouri 29 



21. Black chaff of wheat, showing thin, secondary margin of two gelatin 



colonies. Medium magnification 31 



22. A, B. Black chaff of wheat. Same series as fig. 21 but older and 



more highly magnified 32 



23. Blade of a cucumber leaf attacked by angular leaf-spot showing tear- 



drop ooze of Bacterium lachrymans Smith and Bryan 37 



24. Gelatin colonies of Bacterium lachrymans 38 



25. Colony markings of Bacterium lachrymans on: (A) gelatin and (B) agar. 39 



XV 



