CHAPTER XII 
(@NOTHERA AND THE MUTATION 
THEORY 
The mutation theory was first developed by 
deVries on the basis of his extensive experiments 
with the Evening Primrose, @inothera Lamarckiana. 
This plant was found growing wild at Hilversum, 
near Amsterdam, in Holland. DeVries noticed that 
several aberrant types were growing with the 
typical form, and when he planted in his garden 
self-fertilized seed from Lamarckiana (the typical 
form) he found that these other types reappeared 
in small numbers, atid continued to do so year after 
year and generation after generation. Most of the 
new types themselves bred true with the exception 
that they also gave a few aberrant types in the 
same way as Lamarckiana. The following table 
shows the percentages of certain types obtained 
from Lamarckiana and from some of the new types . 
themselves. 
Soon after the rediscovery of Mendel’s work 
(1900) the data that were rapidly collected regard- 
ing the genetic behavior of many different animals 
and plants made it evident that Cnothera was 
unique in its behavior in many other ways than in 
the relatively great frequency with which it pro- 
duces new types. This led Bateson and Saunders, 
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