LUTHER BURBANK 
“Much as these plants look alike, they bear 
witness to the fact that they have within them two 
entirely different strains of heredity. 
“The acacia will permit us to touch it and 
handle it without showing signs of disturbance. 
“But its cousin, in the same soil, and of the 
same size, immediately folds up its leaves, in self 
protection, at the slightest touch. 
“From this we read the fact that one branch 
of this family has found it necessary to perfect a 
form of self defense, while the other has had no 
such experience in its life history.” 
“I have been much interested lately in an 
experiment with common clover—in producing 
clover leaves with wonderful markings. 
“The only way in which I can account for the 
markings with which some clover leaves will 
bedeck themselves is that, in the heredity of the 
plant, there was a time when, not being poisonous 
itself, it tried to simulate the appearance of some 
poisonous plant, to protect itself from insects. 
“At first thought, it might require a stretch of 
the imagination to understand how this could 
be—yet a closer inquiry shows that the process 
was as gradual and as surely progressive as the 
transformation of the cactus. 
“In clover, as in other plants, there has always 
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