repeat, a strong presumption in favour of a scientific sequence, of an unbroken order of events; but this presumption is not to authorize any hypothesis whatever in order to escape from the other alternative, an immediate intervention of creative power. This, also, is a probability which philosophy recognises, and in which a rational mind may choose to rest till science brings to him some definite result. We are very far from intending to follow the author of the _Vestiges of the Natural History of the Creation_ through all the sciences along which his track has led him. We shall limit ourselves to what forms the most peculiar and startling portion of his work--to his theory of the origin and development of animal life. But for the discoveries of geology a certain philosophy might have been content to say of the animal creation, that it was the law of nature that life should beget life--that reproduction, like nutrition, to which it has been assimilated, is a part of the definition of life--and that, as to a commencement of the various tribes of animals, we are no more bound to look for this than for the commencement of any other of the phenomena of nature. From the researches, however, of geology, it is evident that there was a time when this earth revolved around the sun a barren and untenanted globe--that there was a time when life did make its first appearance, and that in different epochs of the world's existence there have flourished very different species of animals than those which now inhabit it. Here, at all events, the imagination cannot gain that imperfect repose which it finds in the contemplation of an eternal series. It is a plain historical fact, that life had a beginning on this earth, and that from time to time new forms of life, new species of vegetables and animals, have been introduced upon the scene. Here are two great facts to be accounted for, or to be left standing out, unconnected in their origin with that interlinked series of events which creation elsewhere displays. Life reproduces life, the plant its seed, the animal its young, each after its kind, such is the law; but this law itself, when was it promulgated, or when and how did it come into force and operation? For ourselves, in the present imperfect condition of our knowledge, we are satisfied with referring life, in all its countless forms, at once to the interposing will of the Creator. We listen, however, with curiosity and attention to any theory which the naturalist or physiologist may have to propose, so he proceed in the fair road of induction. There is nothing in the laws of life which forbids, but much, on the contrary, which invites, to the same pains-taking examination which has been bestowed, with more or less success, on other phenomena of nature.