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
Catalogue details

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.

    55/698 (page 565)
    The Transformation of the Mexican Axolotl. 565 year (1875) I must abandon my scheme, and this can be done the more readily because, for the theoretical consideration of the facts, it is imma¬ terial whether all or only nearly all the Axolotls could have been compelled to undergo transforma¬ tion. I must not, however, omit to mention that Herr Gehrig, the curator of our Zoological Museum, bred a considerable number of larvae from the same brood as that with which Fräulein v. Chauvin experimented, and that of these larvae six lived over the winter isoithout undergoing meta¬ morphosis. They were always kept in deep water and thus furnished the converse experiment to those recorded above ; they further prove that this whole brood did not have a previous tendency to undergo metamorphosis. If these new facts are to be made use of to explain the nature of this extraordinary process of transformation in accordance with our present conception, the data already known must in the first place be called to our aid. It has first to be established that Siredon Mexicanus never, as far as we know, undergoes metamorphosis in its native country. This Amphi¬ bian is there only known in the Siredon form, a statement which I have taken from De Saussure,^ who has himself observed the Axolotl in the Mexi¬ can lakes. This naturalist never found a single 1 Verhandl. Schweiz. Naturforsch. Gesellschaft. Einsiedeln, 1868.