iT eae 
The Paper Shell on the Tree 
In the course of his experiments, Mr. Burbank produced 
walnuts that were almost devoid of shell, but this proved a 
disadvantage as the birds soon learned the secret. It was necessary, 
therefore, to select specimens with thin shells, instead of those 
with no Shells, to continue the experiment. The 
ones here shown have shells of ideal thickness. 
