The Catholic bulletin. [volume] (St. Paul, Minn.) 1911-1995, 1922-09-16

Lldue Dy GfegOfy Mendel, an Austrian
monk, In the garden of his cloister."
The discovery of Mendel was an
nounced In the proceedings of fair
ly well known scientific paper, but
seems to have been forgotten. The
Darwinian theory then occupied the
scientific mind and Menders brilliant
discovery was almost forgotten for a
quarter of century.
In 1900, Mende's law was re-discov-
cred by the three biologists already
named.
The Law of Heredity," as expound.
ed by Mendel, breaks down the the
DRY of Darwin. Professor Baily states:
"The teaching of Mendel strikes at
the root of two or three difficult and
vital problems. 1t presents new
conception of the proximate mechan-
ism of heredity." In another part of
his paper Professor Baily says: 'In
| the general discussion of evolution,
Mendel's work will be of greatest val
Tie because it introduces new point
Of view, challenges old ideas and opin-
ions, gives us a new theory for dis
cussion, emphasizes the great impor-
lance of actual experiments for tho
solution of many questions of evolu.
ton"
His Law Of Heredity.
Mendel discovered the laws of he
redity after experimentation on some
10000 pea plants. Mendeps original
paper was published in the "verhand-
lungun des MISUNDERSTANDING in
Brunn, for the year 1865, and publish
ed in 1866. His discovery was some
what as follows: He took peas of diff
ferent colors; for instance, yellow
colored peas were crossed with green
colored peas; the resulting pea-seeds
were, in the great majority of cases,
yellow eolored. If these peas were
planted and allowed to be fortified
only by pollen from plants raised from
similar seed, the succeeding genera
ton, however, did not give all vel.
low peas but a definite number of
green. He tried the same experiment
with peas as to other qualities; GER
tain peas are rounded, others are
wrinkled. When these were crossed,
the next generation consisted of wrin-
killed. peas, but the next succeeding
generation presented definite num-
Der of round and definite number of
wrinkled ones and SO on. as before.
i Mende1 formulated his discovery
somewhat as follows. In the case of
each of the crosses the hybrid char
acter, that is, the quality of the re-
sultant seed, resembles one of the
parental forms so closely that the
other escapes observation completely
: or cannot be detected with certainty.
This quality thus impressed on the
next generation, Mendel called dom
inant." AS, however, the reversion of
: definite proportion of the peas in the
third generation to that quality of the
original parent did appear in the sec
: ond generation, thus showing that,
though it cannot be detected, it is
present, Mendel called it the "reces-
: sive quality"
The Hybrid.
Mendel refers to hybrid, the result
Of crossing two distinct species, and
, states, "The hybrid, whatever it's own
character, produces ripe germ cells.
!, which bear only the pure character of
one parent or the other. Thus, one
parent has the character of "A Tin
!, peas), the green color, the other char
. acter b. yellow color-the hybrid
!. will have, in cases of simple domi-
nance, the character ABB or 'BA,"
but not the second quality; in either
> case 1t Is not noticeable. Whatever
the character of the hybrid may be.
whether it be green or yellow. its
germ cells when mature will bear
ter b. but not BOTH
In the third generation. raised by
Mendel, were individuals which show
ed the dominant" character and also
individuals which presented the ere
cessive' character. But the essence
: of Mendel's discovery was that in the
: third generation the numerical pro-
portion of dominants to the recessives
; in the average of series of cases is as
three to one. This occurred with al
most absolute regularity.
In the fourth generation, the prog
: eny of the recessive remained pure
recessives; and in any number of sub
sequent generations they never pro-
duced the dominant type again; that
is, they never reverted to the original
parent, whose quality had failed to
appear in the second generation.
These laws of Mendel reduce to an
exact science the art of breeding, that
Of entire dominance.
II Darwin and Mendei.
II Morgan states in regard to Menders
Law: "The new species have sprung
+ fully armed from the old ones; we un-
/ derstand better how 1t is that we do
!. not see new forms arising, because
they appear, as it were, fully equip
. ped over night. Old species are not
slowly changing into new ones, but
a shaking up of the old organizations
takes place and the egg brings forth
a new Species
MendePs law is quite different from
the gradual transformation of a
species of Darwin. Bistro states:
This throws biology back to the per-
manency of species in themselves.
though successive generations may be
of different species, and 1t does away
with the idea of missing link, since
. there are no gradual connecting gra-