LUTHER BURBANK 
has been brought about, and that in the long lapse 
of ages, the highest forms of existing plants have 
been built up by successive stages of inheritance 
from the lowliest single-celled organisms. 
THE STATUS OF MENDELISM 
In the large view, then, whereas it will be rec- 
ognized that all acquired traits have their influ- 
ence in heredity, yet it will also be recognized thai 
the vast sum of qualities that are of less recent 
origin has preponderant influence, and that the 
racial characteristics as a whole are overwhelming 
in their power as against any individual modifica- 
tions. 
Yet, to complete our picture, we must recognize 
also that nature is not conservative, as she is 
commonly said to be, but is highly progressive. It 
could not be otherwise, in a world in which the 
natural environing conditions are constantly 
changing. 
The basal law of evolution, as we have seen, is 
that the unchanging, the conservative organism, is 
doomed. It is only the progressive, the changeable, 
the plastic organism that can hope to maintain 
itself and perpetuate its kind indefinitely. 
The price of specific life is that the species 
shall not maintain its identity. 
And this interpretation of the situation gives a 
clew, so it would seem, to that important and inter- 
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