If Daniel's researches are confirmed, however, it appears that in some cases, at any rate, the nuclear-protoplasm is so altered by the grafting that when the new embryo is developed, after fusion with nuclear substance from another plant of the same species, the results are apparent only in the progeny, and _the effects of alteration in the cell-protoplasm have been transmitted to the nuclear protoplasm of the germ-cells_--_i.e._ acquired characters have been transmitted and fixed by heredity. Should this prove true the importance of the results can hardly be over-estimated. The matter is too problematical for further discussion here, but we see that any such action may profoundly affect the "constitution" of the resulting plant. Turning now to the case of fungi or other organisms which obtain access to the cell-protoplasm. At the one extreme we have cases where the protoplasm of the diseased plant is rapidly and directly poisoned and destroyed, as in the killing off of seedlings in "Damping Off": near the other extreme we have cases where the foreign protoplasm of the parasite, although it gains complete access to that of the host, merely stimulates the latter to greater activity and itself works for its own ends in conjunction with it--_e.g._ _Plasmodiophora_. In such instances we must figure to ourselves the cells of the root of the Crucifer handing on food-materials to both masses of protoplasm--that of the _Plasmodiophora_ and that of the cell into which it penetrates; and it is immaterial whether both obtain the food-materials directly, or, what seems more likely, the fungus only at second hand and by the medium of the host's protoplasm. 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. We must therefore assume that the general course of building up and breaking down of its protoplasm-molecules go on as usual--or nearly so--in both the host cell and the invader; and that the assimilatory, respiratory, excretory and other functions are carried on in the former as in the normal cell, or are but slightly modified to an extent which does no immediate injury to its life. But we must further assume that the same is also true of the invading protoplasm, and that the _Plasmodiophora_ is also supplied with suitable atom-complexes to build up its protoplasm molecules, as fast as they are shattered and the rejecta burnt off in respiration.