character materials, each of which could be separately inherited. 
Hut, as with most pioneer work, scant attention was given to the 
laws and discoveries which he published in 1866 in the transac- 
tions of the local scientific society of Briinn, and during the thirty- 
four vears in which his work remained unnoticed, Mendel died, a 
disappointed and discouraged old man, It was said he was in the 
habit of comforting himself by repeating “My time will yet 
come.” 
In 1900, three European botanists — Correns, deVries and 
Tschermak— experimenting along similar lines, each independ- 
ently rediscovered the law, and Mendel's long forgotten and 
neglected account was resurrected and once more brought to 
public notice. This time a hearing was gladly granted, a new 
science grew up, and general interest in plant and animal breed- 
ing spread with cyclonic rapidity. The study of heredity became 
a fad which reached its height in the science of eugenics. 
Through Mendel's work, and the encouragement derived from his 
discoveries, the nature of variation and heredity and their rela- 
tion to environment is beginning to be understood. Variations 
can now be classified from the standpoint of cause, instead of 
only by form or by appearance. When three varieties of beans, 
each breeding true to white seed, are crossed with a single vari- 
ety of bean breeding true to red seed-coats, and in each cross 
a different colored progeny is obtained (black, dark blue with 
white specks, brown-gray), we are not thrown back into the old 
time chaos. Thanks to Mendel’s methods and conception, we have 
a clue by which we are able to see law and order in this seemingly 
contradictory result. And what is far more important, we are 
able to repeat this performance again and again with the same 
results. 
Since 1900 many important modifications of Mendel’s original 
conceptions have come about, as might be expected when scores 
of experimenters are engrossed in the experimental study of 
hundreds of different plant and animal forms. Important among 
these modifications is our conception of what constitutes a char- 
acter. The vague meaning attached to this term by the older 
biologists is gradually being replaced by the usage of the chem- 
ists and physicists. In this sense, a character must always be 
looked upon as the combined result of heredity and environment. 
The heredity units themselves are not characters in any sense, 
but, in conjunction with environment, express themselves as 
characters. The units themselves are to be regarded as the 
primary elements of the "living” world, just as oxygen and 
sulphur represent elements of the so-called inorganic world. An- 
other modification of Mendel’s conception is that of linkage. For 
we find that certain characters are either partially or always in- 
herited along with other characters, not always separately as 
Mendel supposed. Many of these characters in certain animals 
t a 
