LUTHER BURBANK 
might better be referred to as a “unit complex,” 
or by some allied term that would suggest its com- 
plicated character. The word “gene-complex” has 
been suggested in a similar connection. 
It would appear that the real purpose of se- 
lective breeding through many generations is to 
remove one after another of the factors that dom- 
inate or mask other factors, so that subordinate 
or recessive factors may make themselves man- 
ifest. 
No one who has experimented widely will 
doubt that it is possible by a series of selections 
extending over several generations to accentuate a 
given character, say to bring out the crinkled for- 
mation of the poppy petal, or the corrugations in 
the leaf of a wild geranium, or an added row of 
petals in a balloon-flower. And it goes without say- 
ing, that, according to the modern terminology, the 
character thus isolated must be represented by an 
hereditary factor which was present in each suc- 
cessive generation utilized in our experiment, but 
which for some reason was not enabled to make 
its influence so potentially felt in earlier genera- 
tions as it was in later ones. 
And the only logical explanation appears to be 
that in each successive generation of the plants 
carefully selected and inbred, there was a new re- 
distribution of factors, always along Mendelian 
[228] 
