All our great continents have been ever so many times, either in the mass or piecemeal, under the waves of the ocean. Nothing hinders that the bed of every great ocean should have been ever so many times turned into dry land. This interchange is going on now in numberless regions of sea and land. All the facts as we find them are such as they might be expected to be had this interchange been going on, as no doubt it has been, through an indefinite past. We are bound to allow millions of years for the formation of the strata that have been already examined. There may be depths below the lowest depths yet explored by geologists; there have certainly been immense intervals which have left no materials for the geologist to explore; and when all the profoundest deep of stratification shall have been explored, we may still find that the record of all these unnumbered millions of years is but, as it were, the latest page of the volume--a page that may have been preceded by a thousand others now almost irrevocably lost or become utterly illegible. There is nothing to hinder the supposition that those earlier pages, if they existed, were, amidst innumerable differences, still in their general aspect very like the latest, as long or longer, as full of the memorials of eventful circumstance, of constant change dominated by and springing from the operation of unchanging laws. As the time is absolutely incalculable which the theory of evolution requires to account for the highest forms of life upon the earth, so the time which all these considerations leave open for the work is absolutely beyond calculation. The theory cannot ask for more than the facts make it possible to offer. We hear men sometimes dwell on an expression which they fancy to be Scriptural, ‘that there should be time no longer[58];’ as if time by any possibility could ever come to an end! It is a pity that they should completely misinterpret the passage on which their opinion fancies itself to be grounded. It is a still greater pity that they should use the language of rational human beings, without being at the pains to determine whether their words have any intelligible meaning: for certainly to the human mind any beginning or end of time is wholly inconceivable. Language itself will not bear with the conception, unless it be consistent to speak of a _time_ when time was not, of a _time_ when time will be no more. There is a poem, and a sweet one, by the present Poet-Laureate, in which the murmuring brook is made to speak the language of the moralist, and to proclaim the transitory nature of all human affairs, by a comparison between the short duration of man’s life and its own unceasing current-- ‘For men may come, and men may go, But I flow on for ever.’