Buddhism gives a peculiar explanation of the disappearance of inferior races. Since the object of the incarnation of the human soul is its progress toward the perfect and divine man; since every human soul must dwell on earth as a member of each one of the sub-races, the time must come when all shall have passed through a given stage. Then there can be no more births into that race. There is, at this moment, a finite number of human souls whose existence is limited to this planet, and no other planet in our chain is at present the abode of humanity. For the larger part of all these souls--at least nine hundred and ninety-nine in a thousand--are, at anyone instant, existing in "the world of effects," in Devachan. All will remain linked by their destiny to this planet, until the moment when all--a few rare, unfortunate, negligent laggards excepted--shall have passed through their last mortal probation, in the seventh root-race. Then will the tide of humanity overflow to the planet Mercury, and this earth, abandoned by conscious men, will for a million years fall back into desolation, gradually deprived of all life, even of all development. In that condition it will remain, sleeping, as it were, for ages--"not dead, but sleeping"; for the germs of mineral, vegetable, and animal life will await, quiescent, until the tide of human soul shall have passed around the chain, and is again approaching our globe. Then will earth awake from its sleep. In successive eons, the germs of life, mineral, vegetable, and animal, in their due order, will awake; the old miracle of creation will begin again, but on a higher plan than before, until, at last, the first human being--something vastly higher in body, mind, and spirituality than the former man--will make his appearance on the new earth. From this explanation of the doctrine that life moves not by a steady flow, but by what Sinnett calls gushes, it follows, of course, that there must come a time when each race, and each sub-race, must have finished its course, completed its destiny. There are no more human souls in Devachan to pass through that stage of progress. For a long time the number has been diminishing, and that race has been losing ground. Now it has come to its end. So, within a hundred years, has passed away the Tasmanian. So, to-day, are passing many races. The disappearance of a lower race is therefore no calamity; it is evidence of progress. It means that that long line of undeveloped humanity must go up higher. "That which thou sowest, is not quickened except it die." If there be "joy among the angels of God, over one sinner that repenteth," why not when the whole human race, to the last man, has passed successfully up into a higher class in the great school?