Middlebury register. (Middlebury, Vt.) 1886-1937, 1910-11-11
Mendel's Law of HereditY.

Members Law.
The famous law of heredty, origi-
mated half century ago by an Austrian
monk, is familiar to all men in the
scientific world, but is not so well
known to those in other vocatlons. A
clear description of it with a story of
how the United States Government has
proven the truth of the monk dis
covery, is here reproduced from an
article in the Sunday Magazine, written
by w. A. DuPuy. The article is as
follows:
In the case of everything that has in
it the spark of life, animal or vegetable,
there is law of heredity that is every
where the same. The law sets down in
definite figures the qualities of each par
ent that will appearin the offspring in
the first, second, third and all the genera
lions that follow. The existence of
such law has been suspected, but it
has remained for the government, after
years of investigation, to declare it a
fact and place back of it the weight of
its authorized scientists.
Gregor Mendel, an Austrian monk,
fifty years ago was pottering about his
clustered garden and breeding plants
together that had strange and distinctive
characteristics. The peculiarities of
the generations that followed certain
crosses and their repetition in mathe-
NAUTICAL accuracy, led him to lay down a
law that has since borne his name and
made him famous wherever scientists
talk of heredity.
Mendel held that where two strongly
contrasting strains were crossed, one
would be likely to prove itself dominant.
The resulting first generation of off
| hn oil tha ~
strain. Members of this generation
would beget offspring three-fourth of
which would follow the dominant strain !;
but one-fourth would react to the weak
err grandparent and show the character
istics of that member that had appear
ed absolutely absent in the first genera
ton. In the third generation these
characteristics of the weaker member
would reappear in the descendants of
those that had shown it in the second,
and remain fixed, reproducing them
selves indefinitely So would the
characteristics of rs per cent of the
dominant strain in this generation be-
come fixed. This would leave an I'M
fixed so per cent that would breed
another generation with the character
istics partly fixed and partly unfiXed and
in the same proportions as the previous
generation All the generations that
followed from this unfxed division
would be like the third generation in
their characteristics and proportions.
Since the time of Mendel, investi-
gators have checked the law back and
forth and found it to their liking; but it
remained for this government to give
the greatest demonstration of them all
and finally set upon it the seal of APP
proval. This it has done and in rather
an odd way.
At Bethesda, in the outskirts of
Washington, is located the experiment
station of the bureau of animal industry,
department of agriculture, where are
carried on the breeding Investigations
of the government. The proving of the
of these.
Under the direction of Dr. E. C.
Shredder, rats were selected as the OBJ
jects of these particular experiments.
There were the two plainly marked
members of the rat family, the plain
gray and the hooded. The first of these
was of solid color, and the second was
white with black head. The colors
were the distinctive points-it was no
trouble to tell which of the parents the
offspring resembled.
Of the first generation resulting from
the cross, every member was solidly
gray like the dominant strain of the
parents. This was as Mendel said il
would be. Two members of this gene
ration were crossed, not necessarily
brothers and sisters, as other lines had
been started simultaneously. In this
case the two gray rats of the first gene
ration produced part gray and part
hooded The hooded rat that had failed
to make itself felt in the first genera
ton, showed in 25 per cent. of the sec
ond. The hooded rats bred hooded in
the following generations. A portion
of the grays, rs per cent. bred all
grays, and remaining portion still hav-
ing the unset characteristics, repeating
the proportions of the second genera
ton.
The number of the families of rats in
which the experiment was followed out
was increased. At the station one en-
tire building was given over to estab-
lishment of the law of heredity. Cage
was piled upon cage, until all the walls
of it were filled, and the lineage of every
family was definitely known, together
with the resulting traits of its members.
|. This has been outlined, year after year,
and the figures kept in the minutest de-
tail. 1t is still going on and the figures
ars still being kept; but the length of it
is already so great as to leave no doubt
as to the findings, and they agree with
those of the Austrian monk. Mendel's
law is correct.
This does not mean that the proper
tons of these qualities are absolute and
unvarying; but that they are in this
proportion on an average. Neither
does it mean that all qualities will re-
main independent; for in many cases
the offspring will be compromise be-
, tween the two parents.
A Black Minorca chicken crossed with
white Leghorn will produce all white
in the first generation. The second gen.
, Grafton, however, will be 20 per- cent as
, the original Minorca, despite the fact
that both parents are pure white in
color. The white was the dominant
, color, but the black was released in the
second generation, and thereafter pro-
duced its like. Frizzled chicken eros
l. Al. 4