Evening star., 1940-05-28
Of Stors, Men
And Atoms
Notebook Of Science Progress
In Field. Laboratory
And Study

In Field. Laboratory
And Study
By Thomas r. Henry.
1t requires as much as 10 per cent
more energy to grow than to stand still.
This finding. which accounts for the
prodigious appetites Of children at some
ages, has just been reported to the child
development section of the National Re-
search Council here by Drs. Charles B.
Davenport, Olive Renfroe and w. l..
Hallock Of the Carnegie Institution of
Washington.
The standard measurement of the rate
at which the body is burning fuel is
that Of basal metabolism-the ratio of
carbon dioxide breathed out to the oxy-
gen inhaled. 1t is greatly increased
when person does any physical work.
Even Just sitting still and thinking
| brings about a slight increase for it
| means that the brain cells are burning
more fuel than is necessary merely to
keep the fire burning. Now DR.. Daven-
port and his associates find that the
mere unconscious process Of growing is
at times very hard work. This may ex-
plain in part the apparent laziness of
children at certain ages. They are al
ready doing about as much work as
their elders.
The tests were carried out at Letch-
worth Village, community for children
near New York, on both boys and girls.
A series of basal metabolism measure
ments were made and any changes
shown were compared with changes of
growth at about the same time. The big
Jump In metabolism the scientists found,
came at about the time of the so-called
aoolescent jump" the big squirt of
growth which comes around the twelfth
year for girls and approximately two
years later for boys, although there are
great individual differences in time.
Curiously, DR.. Davenport found, it
seems to be harder work to grow taller
than to grow heavier. Putting on fat is
lazy kids job.
The change in rate of basal metab-
ollsm,' the scientific report says, prob
ably slightly precedes the squirt of growth
IN stature. There are basal metabolic
processes concerned in growth of the
body that. during the period of adoles-
cent squirt, amount in selected cases to
at least 10 per cent of the total basal
metabolism. Increasing obesity is not
correlated with increasing basal metab-
ollsm although increasing weight Of the
body as whole is
The point might be raised that in
creased metabolism is not due directly
to the demands of increased growth. It
Is well known that the thyroid gland of
adolescent girls tends to become en-
larged. more active thyroid, it is true
means higher metabolsm. But matters
are not so simple as this. First, BOYS
also show increased metabolism without
showing larger thyroids Also. in girls
increased activity of the thyroid without
any accompanying increase in growth
would tend to slenderness of the body
But despite increased activity of the
thyroid, or perhaps because of it, these
girls grow exceptionally rapidly in
stature and weight at adolescence.
increased growth is associated with
Increased oxygen consumption. The in
termediate processes involved are doubt
less many and varied. Very likely thy
roid metabolism is one of them. Involved
also are the secretion of the pituitary
gland. The correlation between stature
departure and metabolic departure from
individual base lines are the same for the
sexes.
The big squirt of growth occurs at a
time of life when the plateau of basal
metabolism has been reached, except for
the adolescent squirt. The infantile pe-
Rod, with its restlessness is passed
Even the slight and variably juvenile
acceleration is finished. The general
curve Of basal metabolism is well estab.
hshed on its declining slope. So evidence
OF an increase of metabolism associated
with the adolescent squirt of growth is a
measure OF the extra metabolism which
Is incurred in the vital activities of
growth.
The correlation between increase in
size OF body and of basal metabolism
during this period that yields the highest
value is obtained in the cases of bows and
girls who gained in weight 2.5 Kilograms
a year, or over. This is, remarkably
enough, somewhat greater than in the
case OF boys and girls to whom the devia-
tions in stature change were about 10
millimeters year.
Also the correlation with weight is
greater In girls than in boys as 67 is tn
A. That is to say, girls who increased
Unexpectedly in weight consumed more
nearly a corresponding excess of oxygen
tnan did boys. The increased weight Of
the girls demanded an increase of oxygen
consumption greater than that of the
boys. A corresponding difference he
tween sexes is found in the correlation
between body build and oxygen consump-
ton. 1t is more than twice that found
IN the male. We may also conclude that
the increase in basal metabolism NAV
precede, as well as occur at the sana
time as the increase in stature.
Agrees With Law for
Preservation Of Parks.
To the Editor of The Star:
During the past few davs r hov.