An Outline of the History of Phytopathology

at the spore-like structures of the entophytic fungi were, in reality, reproductive bodies; that they germinate and hence must serve to propagate their kind; and finally that these entophytes must be independent organisms causing the diseased conditions with which they are constantly found associ-. ated and not the result thereof. To this school belonged such noted mycologists as Bulliard, DeCandolle, Link, Tulasne, Leveille, and others (de Bary, 1853 : 107). Positive proof in the form of carefully checked infection experiments were, however, largely wanting The brilliant and classic studies of the Tulasne1 brothers on the life history of such parasitic fungi as Claviceps, the Erysiphacese, the Uredinales, and the Ustilaginales had unfolded the fact of polymorphism inthese forms. Zoologic investigations1 had established the facts of heteromorphism among insects, notably in the case of aphids. The true relation of gall wasps, tapeworms, and other parasitic animals to their hosts was becoming increasingly clear to scientific workers. 1 Tulasne, L. R. et Ch.: Mdmoire sur les Ustilaginees comparees. aux Uredinees, Ann. Sci. Nat., 3:7: 12-127, 1847; and the following by L. R. Tulasne alone: Memoire sur 1'Ergot des Glumacees, Ann. Sci. Nat., 3 :20 : 5-56, 1853; Second Memoire sur les Uredinees et les Ustilaginees, Ann. Sci. Nat., 4:2: 75-196, 1854; and finally that extraordinary work by the Tulasne brothers, Selecta fungorum carpologia, ea documenta et icones potissi...