Evening star., 1924-08-03
Washingtonian Has Been Pioneer
In Important Practical Science
andLv eSock-H of Sbecmn est;nWo

descendants in a half year, if all sur
ton, cowpeas, fax, figs, peaches,
grapes, soy beans, pumpkins, sugar
beets, sugar cane, tobacco and hun
dreds of other plants.
DR.. Cobb is trying TO effectualize
the use of parasitic names in COM
batting certain insects. a nema has
been found that attacks grasshoppers.
Investigators are now striving to
ascertain If the crops can be protected
against 'hoppers" by colonizing hop
per-killers.
Other nemas are parasitic on de-
structive insects such the cucun-
Der beetle. Some day, Uncle Sam in
his ceaseless duty of guarding our
crops against depredations hopes to
be able TO recruit more of the nemas
that are parasitic on injurious in
sects.
After the successful performance OF
some OF the most searching nema
investigations ever consummated-
work in which he is still busily en-
gaged-Dr. Cobb recommends that
modern agriculture utiliz. every prac-
tical seed treatment n lhod in the
system OF fortifica tions which it is
erecting against nema piracy. Treat
ment Of seed by heat or chemical will
destroy many injurious nemas which
otherwise would jeopardize the finan-
cial success of the potential crops.
The time may come when CONNER
cial seedsmen will have to equip
themselves with seed sterilization out
fits. This is but a logical develop
ment in the upbuilding of an ade-
quate system of crop protection
against unseen nemas now transfer
red from crop to crop on seeds. Even
today, if seed dealers would but in
augurate some precautionary facil-
tiles, their annual sales would be
measurably augmented, for farm
ers who are using the findings Of
agricultural science as their most de-
pendable agent already are beginning
to realize the value of deparasited
seed.
The heat treatment will not neces-
sarily injure the seed where properly
practiced. The temperatures neces-
sary to destroy the nemas are not
high enough to damage the germina-
tion properties. Practical tests have
shown, on the contrary, that the seed
is sometimes aided by the hot-water
treatment where it is planted i'm
mediately after being doctored.
X X * *
NEMA hunting is an enterprise
which teens with thrills both in
the field and laboratory. DR.. Cobb
never knows exactly what new find
he will make during the next twenty
four hours. His explorations into the
science of microscopy are great ad-
ventures, full of scientific romance.
for nematology is still in the pio-
neering age. Every day, almost,
brings forth new marvels. Unsus-
pected nemas are found in previously
unknown hiding places Nothing is
known about these nemas Science
learns the answer to its multitude of
questions about them by studying
their acrobatic antics under the
powerful magnifcation of a perfected
microscope.
Latterly extraordinarily interesting
observations have been made in the
nema laboratories. Under the direc-
ton of DR.. Cobb a predatory nema
| which is parasitic on the gall nema
has been investigated. With pains
taking care a species of this nema
hso
piled by DR.. Steiner and assistants.
A very interesting scientific feat has
been thus accomplished in the rearing
of predatory nema under artificial
conditions.
The predatory nema is known as a
mononch. 1t will destroy from 60 TO
so of the gall nemas daily. When
very hungry the mononch will swal-
low gall nemas whole. Sometimes it
gets the collie from overeating. In
several cases where mononchs swai-
lowed gall nemas intact the latter
turned about and ate their way out
OF the mononchS, destroying their
foes in this drive to liberty. DR.. Cobb
| knows of no less than 60 Of these
al toio' ahu uc
| that there may be hundreds of kinds.
On one occasion in South Sea wa
ters DR.. Cobb could not induce the
native professional divers to descend
after nema specimens. as they be-
came suspicious of his activities or
his outlandish apparatus. The scien-
| tist knew there were specimens to be-
had. He stripped. and, although less
experienced than they in diving, he
plunged time and again into the
multihued waters and each time re-
turned with the specimens which he
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