Evening star., 1948-10-11
Stars. Men and Atoms st.s~-"s
Corn Exposed to A-Bomb
Shows Many Defects
California Scientists Cite Effects
of X.Ray Treatment Also
Bv Thomas r. Henry

Corn grown from seed exposed to atomic
bomb radations-mostly, it is presumed, ex.
tremely powerful gamma or X-rays-shows
an enormous number Of hereditary mutations.
Results of the experiment have just been
reported to the National Academy of Sciences
by DR.. E. G. Anderson of the California Insti.
tute Of Technology, who worked in cooperation
with the Department of Agriculture and the
Naval Medical Research Institute.
Seed corn from a carefully selected line
was placed aboard some of the target ships.
A precisely similar lot of seed was kept for
control growth experiments. Another lot was
exposed to x-ray radiation essentially equiva-
lent to that which was received from the
bomb explosion.
At least so per cent of both the X-rayed
and bomb-exposed seeds produced seedlings
with conspicuous defects, DR.. Anderson reports.
Beneficial changes were not expected. It long
has been known that the vast majority Of
hereditary mutations are detrimental.
Notable among the changes were deficiencies
in chlorophyl, the green coloring matter in
leaves by which plant is able to utilize sum
light to build up sugars and starches There
were all sorts Of pale green, yellow, whitish
and zebra-colored plants. Many types of
defective grains were found. Defects were
carried over to the next generation from the
irradiated parents. Many of these, however,
were so-called "recessives,' hidden hereditary
qualities likely to arise in future generations.
The number of mutations found from both
the powerful X-ray and bomb radiations was
greater than the experimenters had expected.
the report says
Some unknown chemical is released by
earthworms which increases crop yields.
This hitherto unobserved effect is reported
by Drs Henry Hopp and Clarence S. Slater
of the Department of Agriculture's Soil Con-
servation Service 1t is in addition to the
value of the worms in keeping soil in porous
condition
Earthworms, the two scientists report reach
maturity during late winter and spring, re-
produce, and die in the early summer. 1t Is
at this time that their beneficial effect on
crops is greatest. Apparently whatever chemi-
cal they release does not remain unchanged
in the soil and must be utilized by plants
during their active growth period. On cul-
tivated land which has insufficient protection
in the late fall to maintain the earth worms.
they die in early winter. Then almost no
beneficial effect can be found.
The nature of the stimulating substance
remains to be determined At first Drs. Hopp
and Slater believed it to be nitrogen, one Of
the major essentials for plant growth. But the
increased growth occurs even when there is
a super abundance OF nitrogen-far more than
the plants possibly can assimilate. Appar-
emily, the substance Is something not con-
tanned in commercial fertilizer
The stimulating effect was obtained by adj
ding either living or dead earthworms to the
soil. The former seemed to be slightly better
than the latter but the difference was ex-
tremely slight
In either case, the scientists point out, good
soil structure Is necessary. The living worms
apparently both loosen the soil and secrete
the elusive chemical, chiefly during their breed.
ing season.