Evening star., 1938-12-13
OF Stors, Men
And Atoms
Notebook Of Science Progress
In Field, Laboratory
And Study
By Thomas r. Henri.

By Thomas r. Henry.
Mother instinct can be aroused by
any one Of six substances, one Of them
carbolic acid, according to a report Just
made to the trustees OF the Carnegie
Institution Of Washington by Drs. Oscar
Riddle and E. L. Lahr Of the Carnegie
sta1.
They had previously reported that male
rats and immature females could be
made to mother" infant animals when
they were given injections Of prolactin,
the hormone secreted by the anterior
lobe Of the pituitary gland at the base
OF the brain which was first discovered
by DR.. Riddle six years ago. One Of the
primary functions Of prolactin is To
stimulate the excretion Of mothers milk
and 1t has been used with Indifferent
success to increase the milk production
Of cattle.
They now find that the mother love
complex also can be aroused by injec-
tions OF progesterone, one Of the female
sex hormones; testosterone, one of the
male sex hormones; intermedin, a re-
Gently discovered pituitary gland hor-
none; extracts of the whole anterior
lobe OF the pituitary gland, and carbolic
acid. Meanwhile other experimenters
have reported that the same result can
be bought about by removal of the
thyroid gland in males and by the re-
moval OF the pituitary gland in imma-
ture females. The last report is espe-
cially puzzling to the Carnegie Institu-
ton workers because it involves a COM
plete absence of prolactin In the blood
stream.
The milk producing hormone, DR.. Rid
dies report shows, still is by far the most
potent producer of mother love. It
induced maternal behavior in more than
three-fourths OF the female and more
than half OF the male rats. The female
sex hormone was next, producing the
syndrome in about two-thirds of both
males and females. The male hormone
caused this reaction in more than half
OF the females but in only Is per cent of
the males. The newly found pituitary
hormone caused maternal behavior to
appear in more than half of both sexes.
Caroollc acid had the same result in 40
per cent of the females and "a per cent
OF the males. No discernible effects fol-
lowed injection of thyroid, parathyroid
and adrenal gland hormones. Other sex
hormones not only did not produce
maternal behavior but seemed to inhibit
1t when 1t already was present.
The new results, Dr. Riddle points ont
make more difficult than ever an expla-
nation OF the physiological mechanism of
maternal affection, which first appeared
on earth with the warm -blooded birds
and mammals and which has been one
OF tne most potent factors in evolution
oy making possible prolonged infancy
IN which the young can be educated"
oe1ore they have to shift for themselves
Inc otner substances, he says, NAV pro-
ouce the effect by stimulating the
pituitary gland to secret more prolactin.
another possible explanation is that thew
act by 1nhibiting the action of other seq
hormones, both male and female. Pro-
Vlous experiments have been reported in
which the mother love of rats was COM
pletely destroyed by taking out of their
diet all the element magnesium.
III. Riddle reported to the Carnegie
trustees some critical experiments with
doves. He found that when CRYSTALS of
the female sex hormone progesterone
were implanted in the bodies of male
ooVes they started sitting on eggs. Then
the crystals were removed but the birds
continued until the young were Matched
ana then proceeded to feed them until
they were ready to fly away. This proves
ne says, that the maternal instinct does
not require the continuous action of the
hormone itself. The proeesterone seeus
10 SET OH a complex interglandular re-
actlon which, once gotten underway. per-
slsts through the normal broodinp cvcle
IN another experiment the rate of crop
cell increase was determined from the
onset OF the "broodiness" in females, At
tne beginning this was found to be more
than six times as great as at other times
Inc rate was increased still further dur
ing the incubating period until the first
signs OF crop milk appeared just before
.ne eggs were Matched. This rapid growth
is basic action OF prolactin. The ex-
perlment proves, DR.. Riddle believes.
tnat the hormone is operating from the
very beginning of the "motherinp" ne
Rod, although 1t may not necessarily he
the cause of it.
Drs. Riddle and Lahr made near,v
z'ooo tests with rats in their efforts to
untangle the strange hormonal complex
OF mother love. 1t is essentially. thew
stress, subconscious emotional reaction
IN which the brain apparently plays little
part. They believe that its manifesta-
tions in human beings, where it is most
prolonged, probably are due to the same
basic physiological mechanisms as in the
lower animals, but that in all human
races 1t is affected by great number
of conventions which render objective
study difficult.
Hormones, they point out, differ little
from species to species. They now are
trying to obtain purer and purer ex-
tracts of prolactin in an effort to clear
their experiments of any effects exerted
by small amounts of other pituitary hor-
moneS.
Eovesdroppers