244 Early Studies in Bacterial Plant Diseases 



believed that an ascopore form of the fungus should be present 

 But this was not found at that time. 



In August 1893, when Smith submitted at the Madison meeting 

 of Section G -* a paper on " The Muskmelon Alternaria," his work 

 on that new and destructive disease of cucurbits was fairly well 

 completed. Infections with pure cultures, however, had not as 

 yet been secured with reference to the disease of cucumbers, 

 cantaloupes, and squashes. Histological studies made in connec- 

 tion with its symptoms indicated its bacterial origin " almost 

 beyond doubt " and " almost certainly " its transmission by insects. 

 Some anatomical and physiological examinations had been made. 

 But the entire malady was to be restudied and the promised 

 printing of his paper by the Department of Agriculture never 

 appeared. It was at best a preliminary account; with improve- 

 ments made in his laboratory technique, his study of the bacterial 

 wilt of cucurbits would last many years. This subject will soon be 

 considered again more fully. An International Botanical Congress 

 was being held at Madison at the same meetings of the American 

 Association. Other important papers on diseases of plants were 

 presented before Section G. Swingle described briefly the " prin- 

 cipal diseases of citrous fruits " being studied at Eustis: blight, 

 mal di gomma, die-back, etc. P. H. Rolfs, a former student of 

 Pammel and now botanist and entomologist of the Florida station 

 at Lake City, presented a paper on "A sclerotium disease of 

 plants." '' 



The World's Columbian Exposition was then being held at 

 Chicago, and the Department of Agriculture had an important 

 exhibit there. The Microscopical, Entomological, Pomological, 

 Vegetable Pathological, and other Divisions of the Department 

 had prepared elaborate displays befitting the Exposition's magni- 

 tude, and these, housed in the Government Buildings at Jackson 

 Park, required one or more attendants from each Division familiar 

 with the work. A strong interest in accomplishments from the 

 study of plant diseases was especially noticeable. By 1893 ^'' 

 Bordeaux mixture had been successfully used against apple scab, 



^* Prof. Amer. Assoc. Adv. of Sci., 42nd ann. meet., 258-259. 

 ^^Idem, 260. 



^'Report of the Chief of the Division of Vegetable Pathohigy for 1893, op. cit., 

 262-265. Fungicides, 262-263; Bordeaux mixture, 263-265. 



