276 Early Studies in Bacterial Plant Diseases 



lady-beetle from Australia. Giard, Snow, Forbes and others have experi- 

 mented with certain fungous parasites of crop-destroying insects, hoping 

 to spread epidenics among them, but thus far (1902) with only partial 

 success. The dreaded San Jose scale can now be held in check in this 

 country by insecticidal sprays. 



Many disease-prevention principles were being invented or 

 developed. Smith mentioned others: one was the later discovery 

 by Halsted, and others, that heavy liming of the soil may partly 

 prevent club root of cabbage. Another was a hybridization tech- 

 nique. After the manner that Pierce had partly solved the 

 California vine disease problem by bringing in healthy cuttings 

 from disease-free regions, the Dutch in Java some years later 

 considerably checked the spread of Sereh disease of sugar cane 

 by importing healthy cuttings from the hills. 



During Smith's lifetime, the cause of the Sereh disease remained 

 in doubt. But a control method was evolved which he regarded 

 as a "great triumph!" He said '^^ of this: "In 1923 Miss G. 

 Wilbrink in Java demonstrated that sugar-cane cuttings could be 

 freed from Sereh by exposure to warm water (30 minutes at 45° C, 

 followed by 30 minutes at 50° to 53°C). From Sereh-diseased 

 canes treated in this manner healthy plants can be grown." 



One of Smith's main contributions had been his development of 

 a laboratory of plant pathology. His own work exampled a high 

 level of skill and efficiency and in it he perfected many important 

 techniques of investigation. In 1895 a convention of American 

 bacteriologists was held in New York City and, in the course of 

 its proceedings, a committee was named to promulgate a program 

 for the proper study of bacteria. In 1891 Paul Sorauer, as editor, 

 had begun to publish his Zeitschrift fiir Pjianzenkrankheiten and, 

 among its pages, occasionally appeared articles on bacteria. In 

 1892, in Edinburgh and London, The Journal of Pathology and 

 Bacteriology had been started. America in 1896, through the 

 editorship of Dr. W. H. Welch, was soon to have The journal 

 of Experimental Aledicine. Furthermore, in October 1895, the 

 Journal of the American Public Health Association published 

 several valuable papers on bacteriology. An opportunity loomed 

 to fit plant bacteriology into the advancements being made in 

 animal pathology, and of this Smith was not unaware. 



"^ Fifty years of pathology, op. cit., 37. 



