Abstract

ForewordThe motivation for the publication of this lecture is my firm belief that any word that can even slightly clarify and advance the powerful and fruitful idea of the transmutation of species is of value.First, I wish to put an end to the futile discussions which go nowhere since they ignore accumulated knowledge and always start from scratch. I want to proclaim that at the core of the Darwinian theory, regardless of its merit as a whole, lies the transmutation hypothesis, which is nowadays the only legitimate scientific hypothesis on the origin of organic forms. Therefore, futurescientificdiscussions should focus on Darwinian theory alone, as its foundation is irrefutable.This lecture has been printed completely unchanged and unavoidable necessary additions have been transferred to footnotes. This article was already completed when Moritz Wagner'sThe Darwinian theory and the migration law of organism1*was published. Wagner attempts to diminish the role of natural selection in Darwin's theory and I challenge this view in the appendix, which also addresses the factors Wagner emphasized as influencing speciation.Freiburg im Breisgau, August 2, 1868August Weismann.