The Indianapolis journal. [volume] (Indianapolis [Ind.]) 1867-1904, 1903-06-28
THE LAWS OF HEREDITY
HOW THEY ARE BEING WORKED OUT
IN HARVARD LABORATORY.
Interesting Experiments Seem "a
Prove Famous Prfncfple-A
MOuse's Evidence.

Correspondence Of the Indianapolis Journal.
CAMBRIDGE, June 27.-In the basement
of one of the laboratories of Harvard Uni
versity is a happy and contented settle
ment of mice, rabbits and guinea pigs with
pedigrees, many of them, that might well
be envied by the Mayflower descendants.
In fact, compared with some of these mod
est guinea pigs. the best accredited May
flower descendant is little better than
parvenu. And these pigs. mice and rab-
bits, each in it's own way. are proving
the truth of a scientific principle discov-
cred some forty years ago by one George
Mendel an Austrian monk, in the garden
of his cloister-a principle which is known
to science as Mendel's law of heredity.
Mendel, and other later investigators,
proved his law for plants. and the little
animals in the Harvard cages are engaged
in proving it for the higher organisms.
Menders law was originally discovered
by a series of pretty experiments in the
cultivation of garden flowers in which he
crossed different varieties of ordinary gar
den peas and carefully watched the result.
The result proved that IL a pea with yell
low cotyledons, as botanists call the seed
leaves of the young plant, were crossed
with one having green cotyledons, all the
peas resulting from the process would have
yellow cotyledons. If these peas were
crossed with others having similar yellow
cotyledons the result still followed that yell
low was the characteristic color Of the
seed leaves. But If the peas descended
from the original crossing were self-pollin-
ated or crossed with each other the result
would be one green seeded pea for every
three yellow ones. In other words, the peas
inherited a characteristic from the first
crossing that did not appear until the Sec
ond generation. and then only In crosses
between two plants in both of which the
inherited characteristic might be consid-
cred latent. By the discovery and study
of this curious series Of inheritances among
the garden plants of his cloister the Aus
trian monk evolved a law that now, &C
cording to modern scientists, bids fair
to prove as fundamental to right under
standing of heredity as the law of definite
proportions in chemistry"
GUINEA-PIG TRAITS.
To say that science watches. day by day,
the development Of hereditary peculiarities
in many happy families of guinea pigs,
mice or rabbits Immediately suggests a
question: How can one detect the inherited
characteristics of these little animals? One
guinea pig. one might say, is very like
another guinea pig, and one rabbit very like
another rabbit. But visit to the domestic
menagerie at the Harvard geological labo-
ratory shows Immediately that there are
differences in guinea pigs; some OF them
are albinos, for example, snow-white with
pink eyes, while others are only partly
albino-''mosaics." the zoologist calls them
and yet others are angoras. with long hair
like an angora kitten. or "rosetted''-a word
that describes a guinea pig whose hair
grows in such fashion that the timid little
creature presents the appearance of be-
ing chemically exposed to blowy weather.
There are more differences. indeed, among
the guinea pigs than among either the mice
or rabbits, but in all classes there are diff
ferences enough to establish the question
of inheritance and show how this, that, or
the other characteristic has or has not been
transmitted One Of the most curious re-
suits of these Investigations has been the
evolution of race of guinea pigs with four
toes where ordinarily guinea pig has but
three-a curious popularity whose appear
ance in Father Pig and subsequent trans
mission through a series of generations is
only by the theory that Mother Pig, far
back in her unknown ancestry, had had
a similarly four-toed progenitor.
Every creature in this unique scientific
menagerie has an established pedigree and
the record In which the scientist sets down
the birth and life history of the animals I'M
der his charge, has during the last three
years included something over 1500 entries.
This record includes picture of the sub
ject itself, a rough outline drawing on which
are recoraed-somewhat is done on
typical drawing of the human figure when
a new recruit enters the United States
my or navy-the characteristic markings
and color of that particular individual.
Each animal, moreover, is recognizable
personality in the eyes of the scientist, who
can tell you it's genealogy as promptly as
college of heraldry can trace human fam
lily tree and doubtless much more accu-
rately.
PIGS, RABBITS AND NICE.
Naturally the keeper of this curious me-
nagerie becomes very familiar with the
inhabitants of his wire cages all of them
more or less tame, but each retaining withal
more or less personal attitude of mind
toward being picked up by an alien hand
and having its fur measured with a bit of
tape or it's eyes examined for traces of
inherited color. None of the guinea pigs APP
pear to enjoy this familiarity. although it
is equally evident that they are not in the
least terrified by it. The rabbits, on the
other hand, like being petted, and the little
white or gray mice, once you have succeed
ed in catching them by the tail-and that.
by the way, is the correct scientific manner
of catching a mouse-make no further re-
sistance, but submit with grave philosophy
to the interrogations of science.
One of the most interesting creatures in
the collection is the waltzing mouse, who
comes from Japan and whose great recrea-
ton Is to spin round and round and round,
like dancing Dervish. in one direction un-
| til he gets tired, and then to spin round and
round and round in the other. The waltzng
mouse, moreover, appears intoxicated when
| he walks. and the idea that a straight line
| Is the shortest distance between two points
| has evidently never occurred to his philos-
| ophy In mating the Waiting mouse proves
! for animals exactly what Menders expert
ments with the peas proved for plants. His
| descendants, provided he is mated with a
normal mouse with no taste whatever for
| Waiting are all normal, and so also are