cross-fertilizations

Updated: May 25, 2025

In proportion to the abundance of the harvest of each year this period is shorter for some and longer for other species. Isolation in practice is not so simple nor so easy an affair as it is in the experimental garden. Hence we have constant and nearly unavoidable cross-fertilizations with the parent form or with neighboring varieties, and consequent impurity of the new strain.

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