Evening star. [volume] (Washington, D.C.) 1854-1972, 1908-06-22
new SCIENCE OF PROGENY
LAWS OF HEREDITY DISCOVER.
ED BY MENDEL, THE MONK.
Experiments Of Cross Breeding and
1n-Breeding Pease That Grew in
Monastery Garden.

Frank Harper, in Harper's Weekly.
During the past few months a new law
has come to light. a discovery greater
than any made along the same lines since
Wallace. Darwin and Weismann revolu.
tionized biology. It has reduced to an ex.
act science what was believed to be blind
chance: and incidentally 1t will place on
a sure basis the, hitherto problematical
business Of stockbfeeding.
When Gregor johann Mendel, abbot OF
Brunn. died in the year 1884 his friends
mourned him as good monk, who had
dabbled in science and published q few
amateurish papers. chiefly upon pease and
hawkweeds. Nobody dreamed that TWEEN.
ty-four years later '.Mendelism" would be
the key that would unlock the unopened
doors behind which lay concealed the
hidden mysteries of heredity. 1t was not
until the year 1900 that Menders papers
were perused by de Vries and other bot
fore his startling discoveries had been ap-
Piled to all organisms and found equally
correct In every application.
Menders experiments began in the
cross-breeding of numerous varieties OF
pease that grew in the monastery garden.
Among other things, he crossed tall pease
with dwarf pease. sowed the seeds that
resulted, and found that all the progeny
were tall. But Mendel did not stop here.
He allowed this tall progeny to self-fer-
tilize. and. to his surprise, found that the
next generation consisted Of both tall and
dwarf pease. in the exact proportion Of
three tall to one dwarf. He then self
fertilized the dwarfs. and found that their
descendants were all dWarfs through sue
cessive generations SO long as no cross.
breeding occurred; but when he self-fer-
tilted the tall pease he found that the
original proportion of three to one still
held. Three of the progeny were tall to
each that was dwarf; but two-thirds OF
the tall progeny were impure. inasmuch
as they again produced tall and dwarf
pease in the same proportion.
The Dominating Parent.
In brief. Mendel discovered that in
cross breeding the physical Characters
tic of the dominating parent reappears
through all generations In the general
proportion of three to one. This may be
better shown in the following way:
First generation: Tall, fortified by
dwarf
Second generation: All tall.
Third generation: Tall (A); tall OBJ; tall
(C); dwarf CD.
Fourth generation: AS descendants will
ours. DIS descendants will be dwarf for
ever. BIS and C's descendants will be
mixed in the proportion of three tall to
one dwarf. This fourth generation will
reproduce itself exactly as the third and
the cycle will be maintained forever.
Mendel next experimental with round
seed pease and wrinkled seed with SINH
lar results. Actually, out Of 1924 seeds
produced, 5.474 were round and 1850
wrinkled-a ratio OF 2.96 to I. This as
tonishing approximation to the previous
results demonstrated to the experimenter.
If not to science. the invariability Of his
law. And when he crossed pease having
inflated pods with pease having con-
stricted pods. and pease having yellow
seeds with pease having green seeds, the
law was found to be Interchangeable.
Menders years of patient experimental
ton closed with his death. but after the
of his results by de Vries in
vestigations were made In the animal
world. Japanese waltZing mice were
crossed with normal mice. and, since the
Waiting habit is not dominant in the
mouse. but abnormal. the progeny were
normal mice. But when these were in
bred, the Waiting mouse appeared in the
next generation in the ratio Of 1 to 3.
one was a Waiting mouse which, unless
cross-bred, could never produce normal
mice; one was a normal mouse whose
progency could never waltz unless the
waltzing strain were reintroduced by
cross breeding. and two were normal mice
that reproduced. in their descendants. one
walter to every three that were normal.
Horses and Rabbits.
So when white Angora rabbits were
mated with Belgian hares the offspring
were all apparently Belgian hares. the
dominant type. But these. when inbred.
reproduced So Belgian hares to II Angora
the 3 to Mendel formula.
And these Angoras. mated to Angoras.
never again developed in their offspring
any sign Of the Belgian hare: while of the
So Belgians, one-third produced pure Bel
CLAN hares and two-thirds Belgians and
Angoras.
This discovery was applied in a remark
able manner to the breeding Of fowls
Breeders have always found q difficulty in
raising pure blue Andalusians. for when
Two blue Andalusians are crossed one-half