Studies in the theory of descent / by Dr. August Weismann...with notes and additions by the author; tr. and ed., with notes, by Raphael Meldola...with a prefatory notice by Charles Darwin...with eight coloured plates.

  • Weismann, August, 1834-1914.
Date:
1882
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Licence: Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)

Credit: Studies in the theory of descent / by Dr. August Weismann...with notes and additions by the author; tr. and ed., with notes, by Raphael Meldola...with a prefatory notice by Charles Darwin...with eight coloured plates. Source: Wellcome Collection.

    20/698 (page XII)
    XII Translator s Pì'eface. to rise as a whole, cases may occasionally occur where a lower grade of organization is better adapted to certain conditions of life. This principle of degeneration was recognized by Darwin as early as in the first edition of the Origin of Species it was soon perceived to be applicable to the phenomenon of parasitism, and was first definitely formulated by Dr. Anton Dohm in 1875. In a lecture delivered before the British Association at Sheffield in 1879, Prof. E. Ray Lankester ascribed to degeneration a distinct and well-defined function in the theory of descent. Dr. Weismann's explanation of the transformation of Axolotl given in the fourth essay of this work, may be regarded as a special contributiom to this phase of Darwinism. Whilst refuting the idea held by certain naturalists, that such cases are arguments against the origin of species by the accumulation of minute variations, and prove the possibility, of development per saltum^ the theory here advanced (that Siredon at a former period existed at a higher stage of development as and that the observed cases of metamorphosis are but reversions to this lost higher stage) suggests the question whether there may not still be in existence many other degenerated forms quite unsuspected by natural¬ ists. Many of the opponents of Evolution have from time to time denounced this doctrine as leading