The Stem Finally Selected
The direct color photograph print above shows the stem of the final white blackberry. By comparing its color with the color of other stems shown, it will be seen that the dark, purplish-brown of the black Lawton has given way to the greenish stem of the final white blackberry. The color of the stem, it should be understood, is only a guide to the color of the berry which is later to be produced. It does not form the basis of an absolute, fixed law, for outcroppings of old heredity sometimes appear in the stem but not in the fruit. The selection by stems, is, however, of sufficient certainty to warrant its use in such experiments as the production of the white blackberry. Where it failed as a guide in three or four cases, it succeeded in hundreds or thousands of cases.
This image is from: Luther Burbank: his methods and discoveries and their practical application. Volume 2 Chapter 2