variety of plant to another variety independently of all its other 
characters. It was but a natural step, then, to consider that all 
organisms were made up of many independent character materials, 
each of which could be separately inherited. Mendel published 
an account of his work in 1866 in the transactions of the 
local scientific society of Briinn, Austria, where he lived, and for 
nearly forty years it remained unnoticed. 
Then three European botanists, experimenting along similar 
lines, each independently rediscovered the law, and Mendel’s 
long-forgotten account was resurrected and brought out into the 
limelight. A new science grew up, and interest in plant and 
and animal breeding spread with whirlwind rapidity. Through 
Mendel’s work, and the encouragement derived therefrom, we are 
beginning to understand the nature of variation and heredity and 
their relation to environment. We are able to classify the kinds 
of variation from the standpoint of cause. When two varieties of 
corn, breeding true to ears with all white grains, are crossed, 
and the progeny are found to consist of some plants with ears of 
all red grains, others with ears of all blue grains, others with ears 
of all white grains, and still other plants with ears of red and 
white grains mixed, red and blue grains, blue and white grains, 
and blue, red and white grains, we are not forced back to the old- 
time chaos. Thanks to Mendel’s conception, we are able to see 
law and order in this seemingly chaotic result, and, more impor- 
tant still, we are able to secure the same result again and again. 
Many modifications of Mendel’s original conception have taken 
place, as one might naturally expect, when thousands of experi- 
menters are working upon hundreds of different plant and animal 
variations. Important among these modifications is our concep- 
tion of what constitutes a character. We have been forced to drop 
the vague meaning attached to this term by the older biologists 
and adopt the usage of the chemists and physicists. In this 
sense, a character must always be looked upon as the result of 
heredity and environment. The heredity units themselves are not 
characters, but, in conjunction with environment, express them- 
selves as characters. They themselves must be looked upon as 
the primary elements of the living world, just as oxygen and 
hydrogen represent elements of the so-called inorganic world. 
But such modifications, important as they are, are but super- 
structures built on the foundation stones and methods laid down 
by Mendel. 
With the aid of Mendel’s conception, experimenters soon 
came to a new conclusion regarding the role selection played 
in the creation of new varieties. They found that certain varieties 
of wheat, beans, etc., when once freed from impurities by constant 
