Evening star., 1939-03-07
Of Stors, Men j,
And Atoms
Notebook of Science Progress
In Field, Laboratory
And Study
BIZ Thomas r. Henry.

And Study
By Thomas r. Henry.
White robins and black rabbits are
the two latest tricks Of nature to puzzle
biologists.
They are described in reports to the
American Genetic Association in WASH
ington as striking examples of the two
opposite trends in heredity-albinism
and mechanism.
The snow-white robins are progeny
of pair which nests summer after sum-
mer on bush In the yard of H. D. Shaw
at Grinnell, Iowa. The parents who re-
turn every year are normal colored birds,
except that the female has some white
tail feathers. But from each set of eggs
she matches there are from one to three
white fledglings. The last brood con-
tanned two white and one red-breasted
birds.
Whiteness genes are distributed very
widely throughout the animal kingdom,
explains Robert Cook, editor of the asso-
cations official journal, and an albino
specimen may turn up occasionally in
almost any species. Single white robins
have been reported before but in no
previous recorded case has there been
continuous production of them in a
single family.
1t looks like case, he says, in which
both parents have albino genes, condi-
ton that would occur very rarely in
nature. Even here, however, the pro-
duction of white offspring, if the reports
are entirely correct is far In excess of
what would be expected from the known
laws of heredity. There should be one
white bird to three of normal color.
But heredity. he points out, operates
according to laws of chance and the
behavior Of single family does not
necessarily prove the law is wrong.
Human nature may enter the situation,
he says, because of the tendency to note
and count the unusual birds without
paying attention to the numbers of
normal colored fedglings.
Even so the case is considered unusual
because Of the complete segregation of
the color genes in this family. The
birds are either white or normal There
are no brownishwhite ones such as
might be expected in a certain propor-
ton Of such progeny.
The possibility of a race of white
robins becoming established is remote,
the geneticists believe. The gene of
albinism is known as "recessive" with
very strong tendency to give way when
pitted against normal color gene in
the struggle that attends the formation
OF new organism. Still another diff
Guilty Is that white is an unnatural
color for a robin, tending to make it
conspicuous against its normal back
ground OF leaves and hence an easy
prey for its enemies. None of the white
f1edglings have returned to the Iowa
yard second year and all probably have
perished. The majority of white birds
are creatures of the winter, living
against background of snow.
The black rabbits" reported to the
association by DR.. C. M. Albous of the
United States Biological Survey are un-
likely to become established in nature
for the opposite reason. They are snow
shoe hares of the northern woods, nor
mally white against a background of
| snow.
The so-called "melanistic," or black
| genes also are widely distributed in
nature and for the past half century
| there have been uncondrmed reports
of such hares captured in the Maine
woods. The last one was reported by
the hunter to the local game warden
at Jonesboro who sent it to the State
university.
The nose, face and ears of this crea-
ture were intensely black. Most of the
coat was bluish-black, according to DR..
Albous. In his report to the association
he urges that north woods hunters
refrain from killing any more of these
rare creatures but try to trap them
instead so that genetic experiments can
be conducted with them at some biologi-
cal station. If race of black hares
could be established they might be of
considerable value as fur-bearers. The
laws of mechanism, however, are about
as tricky as those of albinism and the
| possibilities Of propagating the strain
are considered remote.
Another genetic abnormahty just re-
ported to the association might be
considered Garden of Eden musk
melon. 1t has perfect flowers" accord
ing to the report of Drs. Charles F.
Poole and Paul G. Grimball of the
Federal vegetable breeding laboratory
at Charleston. S. c. Tests show that
It's fruits start forming earlier and
rlpen more rapidly than those of any
variety now raised during the winter
in the South for Northern markets.
Thus it may prove considerable eco
nomlc asset for vegetable growers.
Its interest to geneticists, however, is
primarily in the fact that it seems to
violate the trend of evolution. 1t is a
wldely-accepted biological theory that
most Towering plant varieties started
with perfect flowers" technical term