Great stress is laid by the materialists on the changeability of certain microscopic forms, and the startling metamorphoses they apparently undergo in different infusions, especially those forms having developmental tendencies towards fungi and certain low forms of algæ. They attribute their different modes of branching, articulation, segmentation of filaments, etc., both to intrinsic tendencies and extrinsic causes, the latter depending, no doubt, in a great measure upon the chemical changes constantly taking place in their respective infusions. These intrinsic tendencies, they would have us believe, depend upon the dynamic force of molecules, rather than any vital unit, or even change in elementary conditions. But "Dynamism" simply implies that force inheres in, or appertains to, all material substance, without specifically designating either the quantity or quality of the inhering force. If these materialists, therefore, use the terms "dynamic force," in this connection, in the sense in which we use vital force, or in the sense in which they use "statical force" as applied to the formation of crystals, in contradistinction from "dynamical force" as applied to living organisms, we have no special objection to urge against this particular formula. It presents no such formidable antagonism as the vitalists would expect to encounter from them. M. Dutrochet is approvingly quoted by Professor Bastian, as asserting that he could produce different genera of mouldiness (low mycological forms) _at will_, by simply employing different infusions. This is unquestionably true, with certain limitations. And the chief limitation is as to _his_ (M. Dutrochet's) will. He might "will," for instance, to plant one field with corn and another with potatoes, but if the husbandman he employed to do the planting should happen to plant the one crop where he had willed to plant the other, and corn should grow where potatoes were planted, and _vice versa_, then he might be said to have produced corn _at will_. And so of his infusions. No change in their conditions enabled him to produce one species, much less a genus, of mouldiness in preference to another, by any change in the infusions employed by him. The power which implants life in the mycological world, implants it in every other world, from that without beginning to that without end. And this implanted life is quite as complete in one form as another,-- "As full, as perfect, in vile man that mourns, As the rapt seraph that adores and burns."