246 Early Studies in Bacterial Plant Diseases 



and of much interest were original studies of chromogenic bac- 

 teria of the Ames flora. ^° 



G. F. Atkinson also had done some especially valuable work. 

 The scientific and practical worth of his bulletin 41, issued in 

 December 1892, from the Alabama College Station on cotton 

 diseases — yellow leaf blight or mosaic disease, f renching, damping 

 off, anthracnose, shedding of bolls, angular spot, areolate mildew, 

 leaf blight, and root gall — made it probably the most important- 

 plant pathological work thus far from the southern states. Imme- 

 diately on going to Cornell University he had begun to study 

 serious tomato diseases, and his bulletin, or part of bulletin, 53 

 of the New York Agricultural Experiment Station there on 

 " Oedema of the tomato," published in 1893, remained for years 

 a leading investigation on the subject. Smith later said of this: ^^ 



[In 1892-1893 Atkinson} experimented with the oedema of the tomato, 

 which is an intumescence and reached the conclusion that on susceptible 

 varieties oedema may be induced by insufficient light and bad ventilation 

 coupled with too much water in the soil, and a soil temperature too near 

 that of the air, leading to the accumulation of acids in the plant and to weak 

 cell-walls, easily stretched as water is imbibed. He says: ""When there is 

 an abundance of water in the plant these acids draw large quantities into 

 the cells, causing the cells to swell, resulting many times in oedema." . . . 

 " Ordinarily there is no increase in the number of cells." 



Smith believed that his experiments should be repeated because, 

 first, those were few by which he claimed to have produced oedema 

 by forcing an excess of water into the plants, and, second, he 

 described no experiments which sought to determine the increased 

 acidity. Atkinson also in 1893 elaborated some pioneering studies 

 of carnation diseases, a subject in which others, prominently Arthur 

 and BoUey, had figured.^' Whetzel has classed two others of his 

 early studies at Cornell, " Leaf curl and plum pockets " (1894) 

 and " Damping off " (1895) as among Atkinson's more important 

 works. 



Atkinson, while at Alabama, secured pure cultures of the causal 

 organism of Pammel's root-rot of cotton. Plant pathologists of 



^" Pammel presented several papers at the Madison meeting of the American Asso- 

 ciation for the Advancement of Science, see Proceedings, op. cit., 263-264. 



'^^ Introduction to bacterial diseases of plants, op. cit., 489. 



•''" H. H. Whetzel, An outline of the history of phytopathology, op. cit., 104, n. 3. 

 See also, Bacteriosis of carnations, by Arthur and Bolley, Bulletin 59, 7 (March, 

 1896), Indiana Agric. Exp't Sta., and authorities cited. 



