THE INHERITANCE OF QUANTITATIVE CHARACTERS IN MAIZE. 
BY COLLABORATION OF R. A. EMERSON AND E. M. EAST.* 
INTRODUCTION. 
When Mendel's law of heredity was rediscovered by Correns. 
de Aeries, and von Tschermak, most biologists were justly 
skeptical of the possibility that it might be general in scope. 
The early disclosure that a wide range of breeding facts in both 
the animal and the vegetable kingdom were made orderly and 
consistent by using the Mendelian notation? brought about only 
a slight change in this attitude. A few optimistic minds believed 
that the similarity of the breeding phenomena in animals and in 
plants indicated that the Mendelian mechanism was intimately 
associated with that fundamental process common to both king- 
doms, — sexual reproduction. Those who reasoned in this manner 
suspected a broad general operation of the law of segregation and 
recombination of unit factors. The remaining great majority 
held to their position of respectful distrust. 
There were several reasons for this situation. A goodly por- 
tion of the responsibility for it rests upon de Vries. who. from 
data of doubtful significance, drew the broad conclusion that 
varietal characters and specific characters obey quite different 
laws of heredity. Unpaired or unisexual characters he believed 
to have sole claim to the rank of specific differences. These char- 
acters, he thought, are incapable of Mendelian segregation. 
Segregating characters he called paired or bisexual qualities, and 
these he believed worthy of only varietal rank. The fallacy in 
de Vries' reasoning is obvious, now that Bateson's presence and 
* Harvard University, Bussey Institution, Jamaica Plain, Mass. 
t The prevailing Mendelian terminology is followed in this paper, but 
it must not be assumed that the writers regard Mendelian formulae as 
other than a helpful descriptive shorthand convenient for describing 
breeding facts. Hypothetical germ cell factors are substituted for somatic 
characters because they are useful in exactly the same manner that hypo- 
thetical formulae are useful in describing chemical reactions. To establish 
the contention that quantitative characters are essentially Mendelian in 
their inheritance, therefore, it is only necessary to show that the notation 
adequately describes the breeding facts. 
RES K ARCH BUL. 2, AGR. EXP. STATION OF NEBR. Published also as a 
contribution from the Laboratory of Genetics, Bussey Institution of Harvard University. 
