Evening star., 1939-08-28
Living Fires Brighter
In Male Than Female
OF Plant Kingdom
British Scientists Told
Tests Show Higher
Breothing Rote
BY THOMAS r. HENRY,
Star Staff Correspondent.

oO 1CdoC ~ 1dl do SCA III lIS IIlOSt
primordial manifestation in the
plant kingdom is concerned, accord
ing to a report to the World Gene
tics Congress, meeting here, by DR..
B. N. Singh, noted plant physiol-
ogiSt Of BenareS, India.
BY a series Of marvelously precise
measurements he found that the
male" rate OF breathing is consid-
erably higher than that Of the fe-
male of the same plant species at
first and that it Is more fluctuating
with advance of age, followed at the
end by sudden drop. They also
have more sugars stored in their
cells at the start, but this drops of
rapidly at the time of the opening
of the buds, while in the "fe-
males" there is marked rise at this
time. The females also have more
nitrogen stored in their bodies.
These differences" Dr. Singh
said, appear to be correlated with
the early aging of the male as
contrast to the more sustained de-
velopment of the others to a fruit
ing condition. Light and tempera-
ture effects on sex expression in
plants have been noted by other
workers and all point to the con-
clusion that the potentiality for
both types of sex is present in plants
at all times and that the conditions
existing within largely influence of
one or the other type Of sex genes"
Effect Of Hormones Explained.
Evidence for "pre-sex" hormones
In all the higher animals and man
was presented in a report by DR..
v. Dantchakoff, Esthonian physiol-
ogist.
1t is we'll known, he said, that
the actual sex hormones. several of
which can be synthesized chemi-
cally, exert strong mascularizing or
feminizing effects on adult ami
mails, especially in the absence of
the normal sex glands. They NAV
cause, Tor example, all the so-called
secondary sex characters" such as
the combs of cocks. the plumage of
go SA's VA viz SOANC CIlCCS,
Yet, he said. in the body these
hormones are the secretions of sex
glands born with the individual. The
physiologist Is confronted with the
conundrum OF something which
seems to cause sex and yet which is
itself caused by the thing it causes
| Ihere cannot be any hormones pre-
ceding the glands. Also it has long
been recognized that there is q def
mite genetic background for sex with
which secretions apparently have
nothing to do.
Changes May BE Shown.
But 1t may be shown, Prof
Dantchakoff said, that while the
differentiation of gland cannot be
determined by a chemical substance
which will later be produced by it,
| chemical substance of the same
| nature may, because cells which will
later go to form the gland possess
special constitution, be produced by
a special type of metabolic activity
IN these undifferentiated cells. We
| have shown by experiment that the
introduction of the sex hormone in
an organism before the process of
sexual differention of the glands is
completed can not only effect the
diderention of the glandular tissues
OF the opposite sex to that from
| which the hormone has been de-
rived, but also the differention of
the accessory sexual organs and
| other bodily characters. It is
established that the primary mani
festations related to genetically de-
termined sex may be overridden by
this method.
IF the processes leading to the
development of normal, genetically
| determined sextuality are compared
with those obtained experimentally,
however, two differences are found.
1t is not possible experimentally to
exclude completely those charac-
teristics relating to the genetically
predetermined sex, and the admin
istration of hormones cannot be
done either early enough or in q
properly balanced manner to simu-
late the natural reaction between
hormone and glandular groundwork
In the organism. In spite of this
the results of experiment and nature
are similar in many respects, al
though the sex changes induced may
only exhibit temporary phase. 1t
is found also that the introduction
| OF the hormone stimulates dispro-
portionately some of the processes
while others are not inhibited suffi-
GENTLY.
Chemical Factor Figures.
But these differences are not
sufficient to support the argument
that the primary substances in
volved in natural sex differentia-
ton are fundamentally different
from the substances used expert
mentally. The similarity in the
processes evolved spontaneously and
those induced by the hormones is
function of the similarity of the
embryonic tissues in both sexes and
of the mechanism acting upon them.
The differences which appear are
conditioned by the presence of a
double-acting mechanism on one
case and of single-acting one in
the other. The chemical factor
initiates the process Of sex deter
mination, even if it does not con-
troll completely the subsequent
differentiation.
Development of double resister"
potatoes. which are immune to at
least two forms of the dreaded po-
tato blight and probably to sew
eral others, was reported by Prof.
R. N. Salaman of Cambridge Uni
versity.
AS far ago as 1914, Prof. Salaman
said. he had developed potato va
rieties which were immune to the
form Of blight, the only one known
at the time, which was responsible
for the great Irish famine OF 1845.
Later these supposed immunes mys-
teriously came down with the
disease.