422 Prof. H. Marshall Ward. Tlie Relations beliveen 



Fig. 7. A dead leaf infested with moulds, especially with JSotrytis, as shown 

 on the grey patches. (Natural size.) 



spreading more or less rapidly from dead and dying parts of a plant 

 to the assumed healthy organs, and it lias been cnstomary to look upon 

 this as a secondary phenomenon due to the " dying-off " of the adjoin- 

 ing parts, the fungus spreading to them as they died. No one 

 questioned the saprophytic nature of the Botrytis* and so the matter 

 istood for a long time. Gradually, however, it came to light that 

 various forms of this Botrytis appear as phases in the life-history of 

 certain sclerotium-bearing Pezizas which were associated in a manner 

 suspicious, to say the least, with epidemic diseases of rape,f clover,^ 

 hemp,§ onions, || hyacinths^" (also Scilla, Narcissus, Anemone, &c), 

 balsams,** Carex, rice, and many other plants. 



Further, this mould was found causally associated with the rotting 



* Of course I am referring to the modern definition of the genus Botrytis, after 

 its separation from the totally different Peronosporese (see ' Annals of Botany,' vol. 2, 

 p. 357). 



f See Coemans in 'Bull. Acad. Boy. de Belgique,' Ser. 2, to1.9, 1860, p. 62 ; and 

 Frank, ' Krankheiten der Pflanzen,' 1880, pp. 531—537. 



X Kuhn, ' Hedwigia,' 1870, No. 4, p. 50 ; Sorauer, ' Pflanzenkrankheiten,' vol. 2, 

 1886, pp. 283 — 288 ; Behm, ' Die Entwickelungsgeschichte eines die Xleearten 

 zerstorenden Pilzes,' Grottingen, 1872. 



§ Tichomiroff, in ' Bull. Soc. Nat. de Moscou,' 1868, 2 (see Hoffmann's * Mykol. 

 Berichte,' 1870, p. 42). 



|| See Frank, op. ext., p. 540, and Sorauer, { Oesterr. Landwirthsch. Woehenbl.,' 

 1876, p. 147, and « Pflanzenkrankheiten,' vol. 2, p. 294. 



*H Meyen, ' Pflanzenpathologie,' 1841, pp. 164 — 172; and Wakker, in 'Bot. 

 Centralbl.,' 1883, voi 14, p. 316. 



** Frank, loc. ext., p. 544. 



