LUTHER BURBANK 
spiny armor, each a stronger attempt to respond 
to environment, were so gradual as to be almost 
imperceptible. 
But those rudimentary, half formed leaves 
which come forth from every eye of the cactus 
slab before the thorns or fruits come out—those 
leaves which, as if seeing that they have no useful 
purpose, as if realizing that they are relics, 
only, of a bygone day, drop off and die—what 
environment has acted to bring them forth? 
And those two smooth slabs that push out when 
the tiny seedling has just poked its fhorny head 
above the ground—to what environment do they 
respond? 
How shall we account for this tendency in a 
plant to jump out of its own surroundings, and 
out of the surroundings of its parents, and their 
parents and those before them—and to respond 
to the influences which surrounded an extinct 
ancestor—to hark back to the days when the 
desert was the moist bottom of an evaporating 
sea and before the animals came to destroy? 
A group of scientists were chatting with Luther 
Burbank when a chance remark on heredity led 
one of them to tell this bear story. 
It seemed, so the story ran, that a baby bear 
[36] 
