1923] 



JENNISON — POTATO BLACKLEG 3 



Burrill ('90, '93) published brief notes on a bacterial disease 

 of potatoes, but as nearly as can be determined, the disease which 

 he studied was the brown rot of potato, later most thoroughly 

 investigated by E. F. Smith. 



A bacterial malady of the potato was described by Prillieux 

 and Delacroix ('90) in France, and what they took to be the 

 causal organism was designated Bacillus caulivorus. The potato 

 disease referred to by Prillieux and Delacroix was described as 

 one which affects the stem, beginning at the bottom and working 

 upwards. To this extent, at any rate, it is comparable to the one 

 under consideration. No description of the cultural character- 

 istics of the organism was presented in their paper and no state- 

 ment was made concerning the method of isolation by which 

 the organism was obtained. A few years later Prillieux ('95) 

 briefly mentioned certain of its characteristics, stating that it 

 developed a green coloration in some media. Laurent ('99) 

 stated that B. caulivorus was probably the common saprophyte 

 B. fluoresence liquefaciens Fliigge. Later, Delacroix concluded, 

 according to Prunet, that B. caulivorus was most probably B. 

 fluorescence liquefaciens Fliigge, which he thought became para- 

 sitic under certain conditions. A more complete review of the 

 work referred to just above will be found in Prunet's ('02) paper. 



One of the early contributions to our knowledge of bacterial 

 diseases of plants in general and of the potato in particular is 

 that of Kramer ('91), who describes quite fully a wet rotting 

 of potatoes. He obtained pure cultures of the supposed etio- 

 logical agent which he described as a spore-bearing, rod-shaped 

 bacterium. 



The potato disease described by Tyron ('94, '99) as occurring 

 in Queensland, Australia, is probably not the blackleg disease. 

 Rather according to Tyron's statements, it is very similar to, if 

 not the same as, E. F. Smith's brown rot disease (see especially 

 Tyron, '99, "Biography," p. 62, and footnote p. 63; also Smith, 

 '14, p. 208). 



Smith's first publication on the brown rot of Solanaceae caused 

 by Pseudomonas (Bacterium) solanacearum E. F. S. appeared 

 in 1896. From the outset there was little or no confusion of this 

 disease with the one under discussion. This paper by Smith is 

 one of the first thoroughgoing and accurate descriptions of a 

 bacterial disease of the potato. Recalling that his work was 



