The mutation theory; experiments and observations on the origin of species in the vegetable kingdom . icable. We can apply this instance to the appearance of mu-tations in general and say that the moment of the actualappearance of the character is preceded by a shorter ora longer period in which the change, although complete,was still in a latent condition. If, for instance, we aredealing with a transformation in flowers, a sectorial anda bud-mutation could occur without becoming externallyvisible. In the first part of this volume (page \23>) Idrew attention to the stamens with red stripes
The mutation theory; experiments and observations on the origin of species in the vegetable kingdom . icable. We can apply this instance to the appearance of mu-tations in general and say that the moment of the actualappearance of the character is preceded by a shorter ora longer period in which the change, although complete,was still in a latent condition. If, for instance, we aredealing with a transformation in flowers, a sectorial anda bud-mutation could occur without becoming externallyvisible. In the first part of this volume (page \23>) Idrew attention to the stamens with red stripes in strijK^dflowers and dealt with the question whether the pollengrains themselves might not difler with regard to thismark, some of them possessing this character and othersnot. Obviously this question may be applied just as wellto those characters which can not be seen in the stamens. 618 Validity of the Doctrine of Mutation. I shall not pursue this train of thought further; l:>utthis much seems to be clear, that germinal variations maybe the results of changes which have already taken place. Fig. 137. Green Dahlia. A branch whose terminal inflores-cence b as well as the lateral one b have become green,as in the remaining parts of the plant, whilst a branchhas arisen at a from an axillary bud, bearing double redinflorescences of normal structure and without a trace ofvirescence. a, flowering and a, a bud. See above, , Fig. 14 (1902). See also pp. 628-629. in the pollen- and egg-cells; and that these changes them-selves may have had their origin before the development Vegetative Mutations. 619 of the sexual cells, and perhaps even before the uri^Miiof the flower itself. In other words: Germinal variations may be regarded as a speeial easeof vegetative mutations; and this possibility always re-mains open where the contrary cannot be proved. Concluding these discussions I propose now to arlducea series of facts in which mutations have occurred vege-tatively, tliat is to s
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