MENDELISM UP TO DATE 
A REVIEW 
Austrian monk, Gregor Mendel, 
published in a provincial journal 
the results of his now famous breed- 
ing experiments with garden peas. They 
lay unnoticed until 1900, when three 
other breeders whose work had _ led 
them to similar conclusions, almost 
simultaneously turned up the work of 
Mendel and gave it to the world. 
Breeding along the lines marked out 
by Mendel at once became the most 
popular method of attack, among those 
who were studying heredity. It is 
largely responsible for the creation of a 
new science—genetics. 
During the past fifteen years, hun- 
dreds of thousands of plants and ani- 
mals have been bred under carefully 
controlled conditions by men interested 
in repeating and extending Mendel’s 
conclusions. The publications on the 
subject are for the most part brief, 
widely scattered, and almost meaning- 
less to one who is not in the current of 
Mendelian research. This has _pre- 
vented many persons from appreciating 
the progress of that research in its 
broad outlines. The present status of 
it is now set forth by Professor T. H. 
Morgan of Columbia University, and 
three of his associates,’ under the title 
of “The Mechanism of Mendelian 
Heredity,’’ their account being based 
principally on their own work. 
Professor Morgan fears that zoologists 
and botanists are tending to look on 
genetics as a field apart, with which they 
have no direct concern. He believes that 
this is a mistaken attitude; that every 
biologist needs a knowledge of genetics; 
and it is to provide the members of the 
profession witha succinct account of what 
they need to know about this science, 
he says, that he and his students have 
written the present book. 
One of the useful functions of the 
‘é IS just half a century since the 
volume should be to bring home to 
readers who have a little knowledge of 
genetics a realization of the fact that 
the term ‘‘Mendelism” is nowadays 
used to cover a number of distinct and, 
in their details, often irreconcilable 
views. Professor Morgan’s Mendelism 
would hardly be acknowledged as such 
by many who think themselves Men- 
delists; and other students have ad- 
vanced speculatively in certain direc- 
tions even farther from the base than 
he has. 
PROGRESS IN MENDELISM 
To put the matter very frankly, we 
will have to consider that a large part 
of the so-called ‘‘Mendelism” which is 
current at present is in some way out 
of date. This is perhaps particularly 
true of the views held by the rank and 
file of eugenists, who are obliged to work 
with a material that is in many ways 
unsuitable for genetic analysis, and 
whose exposition of Mendelian heredity 
rarely fails to provoke a smile of pity 
from the advanced student in the sub- 
ject. A considerable part of the stud- 
ents of genetics are, judged by the pres- 
ent book, behind the times, and working 
with hypotheses that, according to 
the authors, will not stand in the light 
of some of the recent laboratory work. . 
The cause of this state of affairs 1s un- 
doubtedly due mainly to the fact that 
it has been impossible for students to 
get a comprehensive account of recent 
developments in the science; they were 
seeking for light, but none was given 
them. 
It is likely, then, that they will wel- 
come the illumination of Dr. Morgan 
and his co-authors. 
Before we analyze their views, how- 
ever, let us try to get clearly in mind 
the fundamentals of that type of 
heredity known as Mendelian. 
1 The Mechanism of Mendelian Heredity, by T. H. Morgan, Professor of Experimental Zoology, 
Columbia University; A. H. Sturtevant, Cutting Fellow, Columbia University; H. J. Muller, 
Assistant in Zoology, Columbia University; C. B. Bridges, Fellow in Zoology, Columbia Univer- 
sity. Pp. xiii+256, figs. 64; bibliography. New York, 1915, Henry Holt and Company. 
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