Let us first place vividly in our imagination the picture of the two great Kingdoms of Nature, the inorganic and organic, as these now stand in the light of the Law of Biogenesis. What essentially is involved in saying that there is no Spontaneous Generation of Life? It is meant that the passage from the mineral world to the plant or animal world is hermetically sealed on the mineral side. This inorganic world is staked off from the living world by barriers which have never yet been crossed from within. No change of substance, no modification of environment, no chemistry, no electricity, nor any form of energy, nor any evolution can endow any single atom of the mineral world with the attribute of Life. Only by the bending down into this dead world of some living form can these dead atoms be gifted with the properties of vitality, without this preliminary contact with Life they remain fixed in the inorganic sphere forever. It is a very mysterious Law which guards in this way the portals of the living world. And if there is one thing in Nature more worth pondering for its strangeness it is the spectacle of this vast helpless world of the dead cut off from the living by the Law of Biogenesis and denied forever the possibility of resurrection within itself. So very strange a thing, indeed, is this broad line in Nature, that Science has long and urgently sought to obliterate it. Biogenesis stands in the way of some forms of Evolution with such stern persistency that the assaults upon this Law for number and thoroughness have been unparalleled. But, as we have seen, it has stood the test. Nature, to the modern eye, stands broken in two. The physical Laws may explain the inorganic world; the biological Laws may account for the development of the organic. But of the point where they meet, of that strange borderland between the dead and the living, Science is silent. It is as if God had placed everything in earth and heaven in the hands of Nature, but reserved a point at the genesis of Life for His direct appearing.