Note B — Chapter VI

Bull. Soc. Bot. France, 1886 (Rev. Bib., p. 128). La cancrena del Cavolo Fiore (La gangrene humide du Chou-fleur) par M. le Professor O. Comes (Atti del R. Instituto del incorraggiamento alle Scienzie naturali.—Estratta dal Vol. IV, 3^a serie, degli Atti Academici, 1885). [The Humid Gangrene of the Cauliflower.]

"A disease which attacks the crops of cauliflower around Resina and at Torre del Greco, near Naples. The roots of the diseased plants remain sound, or at least appear so, but the subterranean parts of the stem are more or less seriously affected; the bark is disorganized, the wood situated beneath it more or less decomposed, and the pith destroyed for a variable length. Upon microscopic examination the vessels are found filled with gum. M. Comes recognizes in this disease all the symptoms of the affection which has been designated under the name humid gangrene. He thinks that it is the same disease which, by German authors, is attributed to the parasitism of Pleospora Napi, Fuckel, or to its conidiferous form, sporidesmium excitosum, Kuehn. But he considers the presence of these parasites as an accessory phenomenon, as well as that of Cladosporium and Macrosporium Brassicæ. In his opinion the true cause of the alteration of the cauliflower is the humid gangrene, that is to say, a gummy degeneration and putrid fermentation of the tissues, caused by the abundance of manure in the soil and the excess of water in the plant at a time when it is subject to sudden changes of temperature.

"This disease is not confined to cauliflowers; it is common in all garden vegetables, and is of the same nature as that which attacks tomatoes and which was described by this author in the same journal in 1884." [This disease is also mentioned by Victor Paquet, in his "Plantes Potagers" (London, 1846, p. 243), where it is attributed to stagnant moisture].