But the Darwinian hypothesis admits of a more conclusive answer than we have yet given. Past time, it will be conceded, is theoretically if not actually infinite; and in all past time, nature has been tugging away at Mr. Darwin's problem of the "survival of the fittest." It is no two hundred and fifty thousand years, nor two hundred and fifty millions, but an infinite duration of past time that covers the period in which she has been wrestling with this problem. How successfully has she solved it? In the Darwinian sense of the term "fittest," she has not so much as stated her first equation or extracted the root of her first power. She is manifestly as much puzzled over the problem as Mr. Darwin himself. He fails to see that the "survival of the fittest," necessarily implies, or carries with it, the correlative proposition,--the "non-survival of the unfit." And when such a law has been operative for an infinite duration of past time, the "unfit," however infinitely distributed at first, should have disappeared altogether, many thousands, if not millions, of years ago. If the evolutionists are dealing with vast problems, and assigning to nature, unlimited factors to express the totality of her unerring operations, they must be careful to limit the time in which any one of her given labors is to be accomplished. If she makes any progress at all, an infinite duration of past time should enable her to complete her work just as effectually as an infinite duration of time to come.