The inorganic world knows of no constructive process comparable to this. It is only in living beings that we find what James Ward describes as the “tendency to disturb existing equilibria, to reverse the dissipative processes which prevail throughout the inanimate world, to store and build up where they are ever scattering and pulling down, the tendency to conserve individual existence against antagonistic forces, to grow and to progress, not inertly taking the easier way but seemingly striving for the best, retaining every vantage secured, and working for new ones.” (“On the Conservation of Energy,” I, p. 285.) Summing up, then, we have seen that the reproductive process, whereby the metists or multicellular organism originate, resolves itself ultimately into a process of cell-division. The same is true of the protists or unicellular organisms. For all cells, whether they be protists, germ cells, or somatic cells, originate in but one way, and that is, from a preëxistent living cell by means of cell-division. Neither experimentation nor observation has succeeded in revealing so much as a single exception to the universal law of genetic cellular continuity, and the hypothesis of spontogenesis is outlawed, in consequence, by the logic of scientific induction. Even the hope that future research may bring about an amelioration of its present status is entirely unwarranted in view of the manifest dynamic superiority of the living organism as compared with any of the inert units of the inorganic world. “Whatever position we take on this question,” says Edmund B. Wilson, in the conclusion of his work on the Cell, “the same difficulty is encountered; namely, the origin of that coördinated fitness, that power of active adjustment between internal and external relations, which, as so many eminent biological thinkers have insisted, overshadows every manifestation of life. The nature and origin of this power is the fundamental problem of biology. When, after removing the lens of the eye in the larval salamander, we see it restored in perfect and typical form by regeneration from the posterior layer of the iris, we behold an adaptive response to changed conditions of which the organism can have no antecedent experience either ontogenetic or phylogenetic, and one of so marvelous a character that we are made to realize, as by a flash how far we still are from a solution of this problem.” Then, after discussing the attempt of evolutionists to bridge the enormous gap that separates living, from lifeless nature, he continues: “But when all these admissions are made, and when the conserving action (_sic_) of natural selection is in the fullest degree recognized, we cannot close our eyes to two facts: first, that we are utterly ignorant of the manner in which the idioplasm of the germ cell can so respond to the influence of the environment as to call forth an adaptive variation; and second, that the study of the cell has on