_Nihil ex nihilo_ is conceded to be as conclusive an induction as _omne vivum ex vivo._ That is, as without some chemical unit--some primary least considered as a whole--there can be no chemical action, so without some vital unit, in the same primary sense, there can be no vital manifestation. The doctrine of "chemical units" is universally conceded, and that of "morphological units" almost as universally claimed. What greater incongruity is there, then, in assuming the presence between the two of a physiological or vital unit? [5] At all events, it is as impossible to demonstrate the non-existence of the one unit as the other. And so long as legitimate induction supports the doctrine of the Bible Genesis, it is useless to indulge in a contrary assumption which is wholly without verification or proof. But to return to land vegetation. This appeared and flourished throughout the Devonian period, if not anterior to it, and long before the appearance of batrachian reptiles and other low air-breathing forms of life. In fact, there could have been no life-breathing atmosphere until the earlier land vegetation had whipped out its more destructive elements, and paved the way, in necessary conditions, for the appearance of air-breathing animals. Hence the command for the earth to bring forth both marine and land vegetation--the vegetation of the earth--before there was any similar command respecting either marine or land forms of organic life. But by what logical method was this exact order inferred in the Bible Genesis? Neither the Jews, nor their earlier Hebrew ancestors, nor the Phoenicians before or after them, were in any sense of the word metaphysicians; nor did their language admit of those nicer distinctions and speculative conclusions which would have enabled any writer using it, thousands of years ago, to draw the commanding induction contained in this remarkable genesis. There is nothing in the incomparable methods of M. Comte, or the metaphysical spirit of Herbert Spencer, in his most daring speculations, which gives the world a more legitimate and conclusive induction than is contained in this simple statement of the order of creation. That it should have been a mere piece of guess-work on the part of Moses, or any other writer of his time,--covering, as it does, so many particularities of statement, all according with the exact observations of geologic science, and supported by paleontologic records,--requires quite as much credulity of judgment as to accept it for divinely inspired truth. A disciple of M. Comte might object to this conclusion as susceptible of two interpretations, the one a legitimate induction, and the other not. But the mind of the profounder reasoner would accept the interpretation which is supported by the higher reason, and validated by the greater number of conclusively-established facts. In the case of a strongly intuitive mind, it might be possible to guess the exact order of three or four apparently