Some Japanese Walnut Variations
In his experiments, Mr. Burbank has not only gone east for the English walnut, which is in reality the Persian walnut, but he has gone west to Japan and China for the walnuts which grow there, in seeking out new characters to combine with the native California walnut. The nuts shown in the color photograph print above are variations found among the Japanese branch of the species and illustrate clearly the changes in appearance as well as in other characteristics which long continued environment works in plants.
This image is from: Luther Burbank: his methods and discoveries and their practical application. Volume 2 Chapter 5