Mr. Burbank Selecting Cactus Seedlings
The selection of cactus seedlings, in the course of his experiments leading to the development of the Spineless Cactus, was one of the most arduous tasks that Mr. Burbank ever performed. His hands were never free from prickles for months together, and the pain he suffered was almost intolerable. But ultimate success compensated for the disagreeable experience.
This image is from: Luther Burbank: his methods and discoveries and their practical application. Volume 3 Chapter 9