A Well Protected Fruit
Most of the hybrid chestnuts have a spiny covering that affords ample protection against the attacks of birds or squirrels. In this regard, the specimen here shown resembles the typical chestnuts of our eastern forests. There are other specimens, however, that tend to give up their spiny covering, and Mr. Burbank is using these in further experiments.
This image is from: Luther Burbank: his methods and discoveries and their practical application. Volume 11 Chapter 4