The theory rests on two very precarious foundations: the assumption of _spontaneous generation_, on the one hand, and the assumption of a _transmutation of species_ on the other. Each of these assumptions is necessarily involved in any attempt to account for the origin of the vegetable and animal races by natural law, without direct Divine interposition. For if, after the first organism was brought into being, the production of every subsequent type may be accounted for simply by a transmutation of species, yet the production of the original organism itself, or the first commencement of life in any form, must necessarily be ascribed either to a creative act or to spontaneous generation. A new product is supposed to have come into being, differing from any that ever existed before it, in the possession of vital and reproductive powers; and this product can only be ascribed, if Creation be denied, to the spontaneous action of some element, such as Electricity, on mucus or albumen. In this sense the doctrine of spontaneous generation seems to be necessarily involved in the first step of the process of Development, and is, indeed, indispensable, if any account is to be given of the origin of vegetable and animal life; but in the subsequent steps of the same process it is superseded by a supposed transmutation of species, whereby a lower form of life is said to rise into a higher, and an inferior passes into a more perfect organism. But we have no experience either of spontaneous generation on the one hand, or of a transmutation of species on the other. Observation has not discovered, nor has history recorded, an authentic example of either. In regard to the _first_, the author of "The Vestiges" anticipates this objection, and attempts to answer it. The objection is, that "a transition from the inorganic to the organic, such as we must suppose to have taken place in the early geological ages, is no ordinary cognizable fact of the present time upon earth; structure, form, life, _are never seen_ to be imparted to the insensate elements; the production of the humblest plant or animalcule, otherwise than as a repetition of some parental form, is not one of the possibilities of science."[44] Such is the objection; and how does he attempt to answer it? He endeavors to show, first, that the work of creation having been _for the most part_ accomplished thousands of years ago, we have no reason to expect that the origination of life and species should be _conspicuously exemplified_ in the present day; secondly, that the comparative infrequency, or even the entire absence, of such phenomena _now_ would be no valid reason for believing that they have _never_ been exhibited heretofore, if, on other grounds, the doctrine of 'natural creation' or 'life-creating laws' can be rendered probable; and, thirdly, that even in our own times there ARE facts which seem to indicate the reality, or at least the possibility, of "the primitive imparting of life and form