In any case, the latter is for a long time at least not poisoned or maimed, or in any perceptible way injured by excreta from the fungus-protoplasm, although it is evident that each must excrete various metabolites which may soak into and be taken up by the other: on the contrary the host-protoplasm grows larger, attracts more food supplies, makes larger cells, and is evidently stimulated to greater activity for the time being, its behaviour reminding us of the stimulation of cells by means of slight doses of poison referred to previously.
"Disease in Plants"
H. Marshall Ward