toad-flaxes

Updated: May 10, 2025

And this discussion has the further advantage of showing the way, in which perhaps a full and constant race of peloric toad-flaxes may be obtained. Two individuals of different type are required to start from. They seem as yet never to have arisen from one group of mutations.

Hugo de Vries - Species and Varieties, Their Origin by Mutation

Returning now to the often recorded occurrence of peloric toad-flaxes in the wild state and recalling our discussion about the improbability of a dispersion from one locality to another by seed, and the probability of independent origin for most of these cases, we are confronted with the conception that a latent tendency to mutation must be universally present in the whole species.

Hugo de Vries - Species and Varieties, Their Origin by Mutation

But no such proof has been found, and the conclusion seems admissible that the mutation of toad-flaxes ordinarily, if not universally, takes place by a sudden step. Our experiment may simply be considered as a thoroughly controlled instance of an often recurring phenomenon. It teaches us how, in the main, the peloric mutations must be assumed to proceed. This conception may still be broadened.

Hugo de Vries - Species and Varieties, Their Origin by Mutation

I suppose that they are infertile with the normal toad-flaxes of their own sexual disposition, but fertile with those of the opposite constitution. At all events the fact that they may bear abundant seed when properly pollinated is an indication of successful experiments on the possibility of gaining a hereditary race with exclusively peloric flowers.

Hugo de Vries - Species and Varieties, Their Origin by Mutation

Here we have the first experimental mutation of a normal into a peloric race. Two facts were clear and simple. The ancestry was known for over a period of four generations, living under the ordinary care and conditions of an experimental garden, isolated from other toad-flaxes, but freely fertilized by bees or at times by myself.

Hugo de Vries - Species and Varieties, Their Origin by Mutation

This is so much the more probable as Linaria is a perennial herb, and the ancestors of a mutation might still be in a flowering condition together with their divergent offspring. But no such intermediates are on record. The peloric toad-flaxes are, as a rule, found surrounded by the normal type, but without intergrading forms.

Hugo de Vries - Species and Varieties, Their Origin by Mutation

This curious remainder of the original, symmetrical structure of the flower seems to have been overlooked hitherto by the investigators of peloric toad-flaxes. The peloric variety of this plant is characterized by its producing only peloric flowers. No single bilabiate or one-spurred flower remains.

Hugo de Vries - Species and Varieties, Their Origin by Mutation