In the first place, the so-called internal causes of disease is probably a mere phrase covering our ignorance of the factors at work, and although a certain convenience attaches to the distinction between those cases where tender breeds of plants apparently exhibit internal predisposition to suffer more readily than others from parasites, low temperatures, excessive growth, &c.as is the case with some grafted plants, cultivated hybrids, &c.the mystery involved in the phrase internal causes only exists until we find what action of the living or nonliving environment of the essential mechanism of the plant has upset its equilibrium.
Its over-supply is, however, a frequent cause of predisposition to the attacks of parasitic Fungie.g.
The only inkling of possible underlying principles in this orderly process is that there appears to be in respect to certain characters a potentiality or a predisposition through hereditary kinship to evolve in certain definite directions.
2 (1888); Eriksson & Hennings, Die Getreideroste (vide supra); Ward, "On the Question of Predisposition and Immunity in Plants," Proc. Cambridge Phil.
Indeed, the sophists generally had a special predisposition to error of this sort, not only because sophistry was from the beginning a substitute for the pursuit of truth, but also because the successful professor, travelling from city to city, or settling abroad, could take no part in public affairs, and thus was not at every step reminded of the importance of the " material " element of exposition and reasoning.