By CHARLES DARWIN, M.A., Fellow of the Royal, Geological, Linnaean, etc, Societies; author of Journal of Researches During H.M.S. Beagle's Voyage Round the World. London: John Murray, Albemarle Street, 1859. The right of Translation is reserved.
I WILL HERE GIVE a brief sketch of the progress of opinion on the Origin of Species. Until recently the great majority of naturalists believed that species were immutable productions, and had been separately created. This view has been ably maintained by many authors. Some few naturalists, on the other hand, have believed that species undergo modification, and that the existing forms of life are the descendants by true generation of pre-existing forms.
In 1846 the veteran geologist N. J. d'Omalius d'Halloy published in an excellent though short paper (``Bulletins de l'Acad. Roy Bruxelles,' tom. xiii. p. 581) his opinion that it is more probable that new species have been produced by descent with modification than that they have been separately created: the author first promulgated this opinion in 1831.
See "The Origin of Species" for the complete version of the book.
The new species found in November 1967 near Calilegua, province of Jujuy, Argentina, was dedicated to me and called Gastrotheca christiani.
See the publication "Descubrimiento del Genero Gastrotheca Fitzinger en Argentina" by Raymond F. Laurent, Acta Zoologica Lilloana, vol 22, pages 353-4, 1967
Also: "Estudio Complementario de Gasthrotheca Christiani Laurent", by R. L. Laurent, Acta Zoologica Lilloana, Vol 25, p 123-36, 1969.