14 
Research Bulletin, Xo. 2 
characters formed under operation of the Mendelian law. The 
matter is purely speculative, nevertheless it is suggestive. We 
do not know why two factors should exist that apparently cause 
identical characters to be formed in the same plant organ, but 
different factor-carrying apparatus of some kind which makes pos- 
sible independent segregation and recombination in the germ cells 
is indicated. If one accepts — for the sake of argument only — the 
idea that Mendelian factors are expressions of chromosome 
functions (Emerson 1911a), then the location of any factor A in 
chromosome number one would give a monohybrid ratio when 
paired with a homologous chromosome in which A was absent, 
the location of the same factor in both chromosomes 1 and 2 
would give the dihybrid ratio when paired with chromosomes in 
both of which A was absent, and so on to the limit of the gametic 
number of chromosomes. Now if in any line of descent a factor 
X should become located in different chromosomes or in any 
other way be so affected as not to be allelomorphic to itself in all 
combinations, and further if additional expressions of the factor 
should result in a cumulative effect, one might have new quanti- 
tative characters or even apparently new qualitative characters 
formed. This hypothesis we consider very important as it gives 
the first reasonable explanation of the production of new charac- 
ters otherwise than by mutations of unknown cause. 
A second speculation is that when one considers the difficulty 
of distinguishing the zygotes having various formulae even when 
dominance is comparatively perfect, he might expect a population 
of F 2 individuals with almost continuous quantitative variation 
if dominance is imperfect or absent. This gives a clue to a 
Mendelian interpretation of the inheritance hitherto known as 
blended. 
The simplest case of this kind yet explained is the inheritance 
of a peculiar physical condition of the starch in maize (East and 
Hayes 1911). The varieties of maize known as flinty have the 
endosperm starch in a hard translucent or corneous condition. 
Those varieties known as dent have that portion of the starch 
immediately surrounding the embryo and that at the cap of the 
seed in a soft condition so that its great shrinkage while drying 
gives the kernel a dented appearance. 
An eight-rowed yellow flint was crossed with a white dent and 
gave in an intermediate condition as regards the physical 
appearance of the starch. The selfed seeds of this generation 
gave ears in F 2 that ran the whole gamut from flint to dent. 
A few were like pure flint ears and a few were like pure dent 
ears, but the great majority were variously intermediate. When 
followed to the F 3 generation, however, one ear out of sixteen 
of the F 2 ears bred true to the dented condition and one out of 
sixteen bred true to the flinty condition. One cannot describe 
