Intracellular pangenesis : including a paper on fertilization and hybridization / by Hugo de Vries ... tr. from the German by C. Stuart Gager.

  • Hugo de Vries
Date:
1910
Catalogue details

Licence: Public Domain Mark

Credit: Intracellular pangenesis : including a paper on fertilization and hybridization / by Hugo de Vries ... tr. from the German by C. Stuart Gager. Source: Wellcome Collection.

Provider: This material has been provided by the Francis A. Countway Library of Medicine, through the Medical Heritage Library. The original may be consulted at the Francis A. Countway Library of Medicine, Harvard Medical School.

    45/296 page 25
    and in any proportion. This is shown in variegated leaves and striped flowers, where the result of this combination, after corresponding splitting, is almost directly demon- strated to us. Almost endless is the diversity of pattern of variegated leaves, frequently on the same plant, or at least on the different individuals of one and the same crop. Striped flowers, according to Vilmorin, arise through partial atavism from old white-flowering varie- ties of red or blue species.^*' Young varieties usually re- vert by leaps to the ancestral form, while the older ones do so by steps, through the appearance of isolated stripes of the original color on the white back-ground. It is as if the color potentialities were already too much weakened to tint the whole corolla in one effort. The descendents of the first striped flowers, however, soon form broader stripes, and finally return, after a few generations, [at least in some specimens,^^] to the uniform color of the an- cestral form. Extremely peculiar are those cases where hereditary potentialities, which in the active state necessarily ex- clude each other, occur together in a latent state. Instead of giving a long enumeration of many cases, I prefer to describe a well-known case of variability, and select for the purpose the arrangement of leaves in whorls. Two-ranked whorls, the leaves of which stand cross- wise over each other on the successive nodes, belong to the best and most constant characteristics of entire nat- ural families. Less frequent are the cases of three- and more-ranked whorls. Quite frequently, however, one i'*Vilmorin, L. Leveque de. Notices sur V ameliorations des plantes par le semis, pp. 39-41. 1886. (According to modem views the stripes are due to a separate character, de V. 1909.) i^Matter in the body of the text in brackets has been introduced anew into the translation by the author of the original. Tr.
    digitised image 1
    digitised image 2
    digitised image 3