Mr. Burbank at Work
Mr. Burbank is here selecting among boxes of second-generation thornless blackberry hybrids. Some of these specimens are a cross between the thornless blackberry and the white blackberry; others between the thornless and the Himalaya blackberry. Through these experiments Mr. Burbank hopes to rid all of our best varieties of blackberries of their thorns.
This image is from: Luther Burbank: his methods and discoveries and their practical application. Volume 6 Chapter 1