Disease, from time to time, will ease the pressure. Diseases are parasites, and it must not be forgotten that just as there are drifts in the world of man, so are there drifts in the world of micro-organisms—hunger-quests for food. Little is known of the micro-organic world, but that little is appalling; and no census of it will ever be taken, for there is the true, literal “abysmal fecundity.” Multitudinous as man is, all his totality of individuals is as nothing in comparison with the inconceivable vastness of numbers of the micro-organisms. In your body, or in mine, right now, are swarming more individual entities than there are human beings in the world to-day. It is to us an invisible world. We only guess its nearest confines. With our powerful microscopes and ultramicroscopes,
