The system of the transformation of species is no less refuted by science than by the instincts of common sense. It rests upon no tangible fact, on no principle of scientific observation or historic tradition. {22} All the facts ascertained, all the monuments collected in different ages and different places, respecting the existence of living species, disprove the hypothesis of their having undergone any transformation, any notable and permanent change: we meet with them a thousand, two thousand, three thousand years ago, the same as they are at the present day. In the same species the races may vary and undergo mutual changes: the species do not change; and all attempts to transform them artificially, by crossings with allied species, have only resulted in modifications, which, after two or three generations, have been struck with barrenness, as if to attest the impotence of man to effect, by the progressive transformation of existing species, a creation of new species. Man is not an ape transformed and perfected by some dim imperceptible fermentation of the elements of nature and by the operation of ages: this assumed explanation of the origin of the human species is a mere vague hypothesis, the fruit of an imagination ill comprehending the spectacle that nature presents, and therefore easily seduced to form ingenious conjectures: these their authors sow in the stream of events unknown and of time infinite, and trust to them for the realization of their dreams. {23} The principle of the fundamental diversity and the permanence of species--firmly upheld by M. Cuvier, M. Flourens, M. Coste, M. Quatrefages, and by all exact observers of facts--remains dominant in science as in reality. [Footnote 4] [Footnote 4: Cuvier--Discours sur les Révolutions du Globe, pp. 117, 120, 124 (edit. 1825); Flourens--Ontologie Naturelle, pp. 10-87 (1861); Journal des Savants (October, November, and December, 1863); three articles on the work of Ch. Darwin, On the Origin of Species and the Laws of Progress among Organised Beings; Coste--Histoire Générale et Particulière du Développement des Corps Organisés; Discours Préliminaire, vol. i. p. 23; Quatrefages--Metamorphoses de l'Homme et des Animaux, p. 225 (1862); and his articles On the Unity of the Human Species, published in the "Revue des Deux Mondes," in 1860 and 1861, and collected in one volume (1861).] {24}