Mr. Burbank Selecting Cactus Seedlings
Remember that most of these little fellows are covered with spicules. Mr. Burbank's hands are also covered with spicules; and his clothes are full of them. He asserts that the task of dealing with these tiny citizens, in the effort to educate them into spinelessness, was the most painful one in his experience.
This image is from: Luther Burbank: his methods and discoveries and their practical application. Volume 8 Chapter 6