APPENDIX. 



In conformity to the writer's custom of keeping things separate until it has been defi- 

 nitely established that they are identical, the following diseases are put by themselves, 

 although it is not unlikely that some of them are due to Bacterium solanacearum. There is 

 the more reason for suspending judgment in some of these cases, because in recent years 

 through the labors of Dr. Appel, in Berlin, we have come to recognize a widespread disease 

 of potatoes similar in some respects to the one described by the writer, as due to an entirely 

 different organism (see Basal stem-rot of potato, vol. IV), and also because a full description 

 of Bad. solanacearum has not been available. [Recently, I have ceased to have doubt 

 concerning identity of the American and Dutch East Indian Disease. See Wilt-Diseases 

 of Tobacco.] 



THE NEW ZEALAND DISEASE. 



Kirk is authority for the statement that Bad. solanacearum causes a disease of potatoes 

 in New Zealand. It is not widespread. 



THE AUSTRALIAN DISEASE. 



In 1894, the entomologist, Mr. Tryon, reported the appearance in Queensland of a new 

 and destructive disease of potatoes and tomatoes, ascribed to a bacterial parasite which fills 

 the vascular system, wilts the plant, and destroys the tubers. 



The leaflet, which is only a brief excerpt from an unpublished MS. report of Mr. Tryon 

 to the Department of Agriculture at Brisbane, mentions no inoculation experiments and 

 contains no description of the organism. The reader is given no information concerning it, 

 other than what may be inferred from the following statements: "A small, living microbe, 

 having an average length of less than one ten-thousandth of an inch, resembling in appear- 

 ance the bacillus of chicken cholera and other organisms." (The italicizing is mine.) In the 

 tubers the disease first appears as "an indistinct, translucent line running parallel to the 

 outer margin" of the tuber when cut across. "They soon, however, commence to rot, 

 decay starting in the more superficial portions of the tissue, and the potato substance is 

 eventually converted into an offensive, odorous, tenacious, whitish slime." (Italics mine.) 

 This leaflet deals chiefly with suggestions for treatment and does not materially help the 

 pathologist or bacteriologist. 



In June 1895, Mr. Tryon stated that he had had an opportunity of reinvestigating the 

 new potato disease and that the microbes are "scarcely distinguishable from those which are 

 met with in diseased sugar-cane. " "They are found clogging up the vessels of stems, roots 

 and rhizomes, and, in the initial stages of the disease, nowhere else." The disease here 

 referred to is Cobb's gumming of sugar-cane, due to a honey-yellow bacterial organism. 

 Without further description the organism is therefore designated Bacillus vascularum solani. 



In 1895, Helms reported on several potato diseases occurring in the Clarence River dis- 

 trict in New South Wales, in south latitude 29 to 30 . The paper is agricultural rather than 

 bacteriological. Judging from the plates, one of these diseases (No. 1) is like Prillieux's 

 potato disease ascribed to Bacillus caulivorus, and another (No. 3, p. 328) is possibly like 

 that due to Bad. solanacearum. No cultures or inoculations are mentioned, and positive or 

 even presumptive identification from the figure is impossible. If it were infected with Bad. 

 solanacearum, the tuber in longitudinal section might be expected to show decay at the stem 

 end, but it is not so represented. 



In 1899, Tryon identified his Australian disease as that described by me and intimates 

 that his name, Bacillus vascularum solani, should have been used in my bulletin on "The 

 brown rot of tomatoes, egg-plants, and potatoes," published in 1896. I would have used 



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