Origin of Species Variorum

An Historical Sketch of the recent Progress of Opinion on the Origin of Species. — — — — — — — — ↑

I WILL here attempt to give a brief, but imperfect sketch of the progress of opinion on the Origin of Species. The great majority of naturalists believe that species are immutable productions, and have been separately created. This view has been ably maintained by many authors. Some few naturalists, on the other hand, believe that species undergo modification, and that the existing forms of life have descended by true generation from pre-existing forms. Passing over authors from the classical period to that of Buffon, with whose writings I am not familiar, ↑ Lamarck was the first man whose conclusions on this subject excited much attention. This justly-celebrated naturalist first published his views in 1801, and he much enlarged them in 1809 in his 'Philosophie Zoologique,' and subsequently, in 1815, in his Introduction to his 'Hist, Nat. des Animaux sans Vertèbres.' In these works he upholds the doctrine that all species, including man, are descended from other species. He first did the eminent service of arousing attention to the probability of all change in the organic as well as in the inorganic world being the result of law, and not of miraculous interposition. Lamarck seems to have been chiefly led to his conclusion on the gradual change of species, by the difficulty of distinguishing species and varieties, by the almost perfect gradation of forms in certain organic groups, and by the analogy of domestic productions. With respect to the means of modification, he attributed something to the direct action of the physical conditions of life, something to the crossing of already existing forms, and much to use and disuse, that is, to the effects of habit. To this latter agency he seems to attribute all the beautiful adaptations in nature;— such as the long neck of the giraffe for browsing on the branches of trees. But he likewise believed in a law of progressive development; and as all the forms of life thus tended to progress, in order to account for the existence at the present day of very simple productions, he maintained that such forms were now spontaneously generated. ∗