eversporting

Updated: May 3, 2025

Hence in saving seed, it is impossible so to select the plant, that an occasional white does not also appear among the double flowers, agreeing in this deviation with the general rule of the eversporting varieties. I commend all the above instances to those who wish to make pedigree-cultures.

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

This diversity is repeated yearly, even from the purest seed. We will now discuss the constant seed-varieties, leaving the inconstant and eversporting types to a subsequent lecture.

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

Hence it may be assumed that the "one-leaved" ashes have sprung suddenly but frequently from the original pinnate species. The pure type of Willdenow should, in this case, be considered as due to a slightly different mutation, perhaps as a pure retrograde variety, while the varying strains may only be eversporting forms. This would likewise explain part of their observed inconstancy.

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

Even in the cases of eversporting varieties, where two opposite types are united within one race, and where the succeeding individuals are continually swinging from one extreme to the other, passing through a wide range of intermediate steps, the limits of the variety are as sharply defined and as free from real transgression as in any other form.

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

But here it is assumed in the clearly defined sense of a systematic variety, which includes all subdivisions of species. Such subdivisions may be, from a biological point of view, elementary species and also be eversporting varieties. They may be retrograde varieties, and the two alternating types may be described as separate varieties.

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

Combining the stability and the qualities of sports in one word, we may evidently best express it by the new term of eversporting variety. We will now discuss the exact nature of such varieties, and of the laws of heredity which govern them. But before doing so, I might point out, that this new type is a very common one.

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

Quite on the contrary it is universal in eversporting varieties. Moreover it may be ascertained and studied in connection with the most widely different morphologic abnormalities, and therefore affords easily accessible material for statistical inquiry.

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

Lastly, we have to consider those varieties, which vary in a much wider range than the ordinary ones, and seem to fluctuate between two opposite extremes, as for instance variegated leaves, cultivated varieties with variegated or striped flowers, double flowers and some other anomalies. They are eversporting and ever-returning from one type to the other.

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