A. S. HoiiNE 185 



Various bacterial diseases of tlic potato have been described during 

 the hist twenty-five years. In 1890 Prillieux and Delacroix^ recorded 

 a bacterial disease attackiiig the stem of the potato. Other bacterial 

 maladies were subsequently described by Erwin F. Smith'^ in the United 

 States (1896) ; IwanofE^, in Russia (1899) ; Harrison^ in Canada 

 (1906) and by Miss Dale^ (1912). The disease known as black-leg or 

 Scliwarzbeinigkeit, which is of sporadic occurrence in Great Britain, has 

 been attributed to various bacteria by different investigators. Frank^ 

 isolated a bacterium which he called Micrococcus 'phytojihthorus (1899) ; 

 AppeP (1902 and 1901), Bacillus phi/lophlhoni.s, which is possibly 

 identical with Frank's organism; C. J. J. van liall*^, in Holland (1902), 

 B. alrosepficus ; Pethybridge and Murphy^, in Ireland (1911), Bacillus 

 nielanogenes. Harrison's disease possibly belongs to this group. 



On the American continent considerable attention is being given to 

 two comparatively recently described fungal diseases — potato wilt, due 

 to Fusarium oxysporium, described by Erwin F. Smith and Deane B. 

 Swingle^'' in 1901, which is widespread in America, but, according to 

 W. A. Orton^^, absent from Europe ; and Verticillium wilt, due to 

 Verticillium alboatrum, described by Reinke and Berthold^^ j^ 1879, 

 present in America and Europe. Verticillium wilt has recently been 

 recorded in Ireland by Pethybridge^^. 



Potato collar-rot caused by the Basidiomycete, Hypochmis solani 

 Prill, and Del. occasionally occurs in Britain. 



The problem of potato scab has become an increasingly important 

 one in the United States. The American scab is said to be caused by 

 an organism isolated by Thaxter^* (1890) who named it Oospora scabies 



^ Prillieux and Delacroix in Complcs rend., cxi (1890), p. 208. 

 2 Erwin F. Smith in U.S. Deft. Afjric. Div. Plant Path. Bull, 12 (1896). 

 ^ Iwanoff in Zeitschr. f. Pflanzcnkrankkeiten, ix (1899), p. 129. 

 * Harrison in Centralblait fiir Bakt., n, Abt. xvii (1906), p. 34. 

 ^ Elizabeth Dale in Annals of Botany, xxvi (1912), p. 133. 

 « Frank in Centralblatt filr Bakt., ii, Abt. v (1899), p. 98. 

 ' Appel in Arb. a. d. biol. Abt. a. Kais. Gesund, ii (1902), p. 373 ; iii (1904). 

 ^ C. J. J. van Hall in Bijdrarjen tot de Kennis der bakterieelle Plantenzickten, Diss., 

 Amsterdam (1902). 



^ Pethybridge and Murphy in Proc. Roy. Acad, xxix, sec. B, No. 1 (1911). 



10 Erwin F. Smith and Deane B. Swingle. U.S. Dept. Agric. Bur. PL Ind. Bull, 55 (1904). 



11 W. A. Orton in U.S. DepL Agric. Bur. PL Ind. Bull, 64 (1914). 



12 J. Reinke and G. Berthold. Die Zersetzung der Kartojfel durch Pike. Berlin (1879) 

 1' G. H. Pethybridge in Jour. Dept. Agric. and Tech. Instruc. Ireland, xm. No. 3 



(1913), p. 23. 



" R. Thaxter in Conn. Agr. ExpL Sta. RepL (1890), p. 81. 



