Experimental studies on the duration of life. XIII. The influence of different feeding on the duration of life of the imago of Drosophila melanogaster


Alpatov, W.W.

American Naturalist 64(690): 37-55

1930


Summarizing, it has been shown in this paper that : (1) The relation between the duration of life and different factors is expressed by quite different types of curves. Temperature and duration of life are connected by a simple exponential curve, while starvation (data from KopeC) and duration of life at different grades of intermittent starvation can be represented by the upper part of a logistic curve. (2) Drosophila females emerged from larvae taken from the food before the end of the normal larval feed-ing do not differ in their duration of life from the controls. The males show even a longer (although statistically not very significant) duration of life as compared with the controls. This shows that a reduction in body size does not lead inevitably to a reduction of the duration of life, as has been the case with "room" and "cold" temperature flies which differed in size of the body and of the duration of life. (3) Keeping flies on synthetic food with yeast and without it indicates that absence of yeast reduces greatly the duration of life of males and females. Very likely the carbohydrates available in the synthetic food are not sufficient for nutrition of adult Drosophila, and additional substances included in living yeast cells are required. (4) Changing synthetic food with yeast every day and every second day indicates that the female duration of life is not affected by this procedure, while males in this experiment show a much shorter duration of life when transferred to new bottles every day. This difference may perhaps be attributed to sex differences in metabolism, or food requirements of male and female organism. Every day food changing can possibly be considered as a partial starvation, because yeast shows growth only after twenty-four hours, and changing food every day does not permit the flies to have yeast growth in such abundance as in the case when the bottles are changed every second day. It is also possible that the results for the males in this particular experiment are not typical.

EXPERIMENTAL
STUDIES
ON
THE
DURATION
OF
LIFE
XIII.
THE
INFLUENCE
OF
DIFFERENT
FEEDING
DURING
THE
LARVAL
AND
IMAGINAL
STAGES
ON
THE
DURATION
OF
LIFE
OF
THE
IMAGO
OF
DROSOPHILA
.211ELANOGASTER
1
W.
W.
ALPATOV
2
I
ALTHOUGH
the
fruit
-fly
has
been
for
almost
thirty
years
a
favorite
object
of
experimental
entomology
(see
Castle,
Clark,
Mast
and
Barrows,
111),
the
fi
rst
accurate
paper
on
duration
of
life
of
this
insect
was
published
only
in
1921
(Pearl
and
Parker,
21),
opening
a
new
period in
the
history
of
the
experimental
study
of
duration
of
life
in
general
and
that
of
insects
in
particular.
Sufficient
time
has
passed
since
that
publication
to
justify
the
making
of
a
short
review
of
all
attempts
in
this
fi
eld.
This
is
done
in
summarized
form
in
Table
I.
It
can
be
seen
from
this
table
how
diversified
are
the
factors
which
have
been
studied
in
their
application
to
the
duration
of
life.
At
the
same
time
it
is
evident
that
all
these
efforts
are
far
from
being
sufficient
to
give
us
a
complete
picture
of
the
relationship
of
different
factors
to
the
duration
of
life.
For
instance,
a
whole
group
of
external
factors
like
radiant
energy
of
different
wave-
length,
electricity
and
magnetism
has
never
(with
one
exception
—Northrop)
been
studied
in
relation
to
lon-
gevity.
The
feeding,
and
particularly
the
influence
of
different
foods
on
duration
of
life,
has
also
never
been
tested
on
Drosophila.
Other
insects
like
bees
(Phillips,
118)
proved
to
be
excellent
material
for
studies
of
influ-
ence
of
different
foods
on
duration
of
life.
Another
point
to
be
emphasized
is
that
even
in
the
cases
of
thor-
1
From
the
Institute
for
Biological
Research
of
the.
Johns
Hopkins
Uni-
versity.
2
Research
fellow
of
the
International
Education
Board.
37
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TABLE
I
REVIEW
OF
THE
QUANTITATIVE
DATA
RELATING
TO
THE
INFLUENCE
OF
DIFFER-
ENT
FACTORS
UPON
THE
DURATION
OF
LIFE
IN
Drosophila
melanogaster
Groups
of
factors
Factor
Author
Year
Influence
found
or
not
and
its
character
P
p
C)
H
Mutation
Line
breed
strains
Mutations
Mutations
Temperature
of
imaginal
life
Temperature
of
imaginal
life
Temperature
of
the
devel-
opment
Ventilation
H
per
ill
food
Cf
r2
JD
,
Food
and
feeding
n
o
Absorbent
pa
-
Etherization
Starvation
and
5
per
cent.
alcohol
Starvation
with
water
Complete
starvation
Intermittent
starvation
Prolongation
of
larval
life
by
underfeeding
Embryonic
juice
and
larval
pulp
Agar
+
water,
salt
and
dextrol
or
"
glucose
-
agar
"
Aseptic
larval
and
pupal
life
Aseptic
whole
life
g-
Density
of
population
P
w
,
-d
o
P-
b.02
bA
7-1
ce,
1
C2
5'
"
°
This
content
09:49:32
AM
Hyde
Pearl
and
Parker
Pearl,
Parker
and
Gonzalez
Gonzalez
Loeb
and
Northrop
Alpa.tov
and
Pearl
Alpatov
and
Pearl
Pearl
and
Parker
Pearl
and
Parker
Northrop
1913
Shortens
the
duration
of
life.
1922
Short
and
long
lived
lines.
1923
Shorten
the
duration
of
life.
1923
Shorten
the
duration
of
life.
1917
Low
temperature
increases
the
duration
of
life.
1929
Low
temperature
increases
the
duration
of
life.
1929
Low
temperature
increases
the
duration
of
life.
1922
Live
longer
ill
ventilated
vials.
1921
No
effect.
1925
Above
100
meter
candles
the
duration
of
life
is
rapidly
shortened.
Pearl,
Miner
and
1927
Parker
Pearl
and
Parker
Sekla
Lutz
Pearl
and
Parker
Kope6
Northrop
Pearl
and
Parker
Loeb
and
Northrop
Steinfeld
No
effect.
1922
No
effect.
1928
Alcohol
prolongs
the
du-
ration
of
life.
1915
Shortens
the
life.
1924
Shortens
the
life.
1928
Shortens
and
(B)
pro-
longs
the
duration
of
life.
1917
No
effect
on
imaginal
life.
1922
No
effect.
1917
Life
longest
on
"
glucose-
,
agar.
1928
Aseptic
conditions
pro-
long
the
duration
of
life.
Pearl
and
Parker
Pearl
and
Parker
Pearl
and
Parker
Lutz
1922
1923
There
is
an
optimal
den
-
1927
sity
of
population.
1915
Negatively
related
to
the
duration
of
life.
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subject
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No.
690]
STUDIES
ON
THE
DURATION
OF
LIFE
39
ough
study
of
the
influence
of
a
particular
factor
on
the.
duration
of
life
the
character
of
the
functional
relation-
ship
between
the
particular
factor
and
the
duration
of
life
has
usually
remained
undiscovered.
Exceptions
are
such
factors
as
temperature
(Loeb
and
Northrop;
Alpa-
tov
and
Pearl),
density
of
population
(Pearl,
Miner
and
Parker,
117)
and
light
(Northrop,
115).
Unfortunately,
the
last
paper
gives
only
a
very
abbreviated
summary
of
the
results,
without
showing
the
original
data
or
even
the
calculated
constants.
These
remarks
give
a
certain
justification
for
showing
in
Fig.
1
curves
based
on
data
published
by
Klope6
(114).
4
1
0
36
,32
40
-
---------
i+
e
—730/369+
O.
090.9087x
/6
y
-
e
--
452//5/
+
006822995X
/2
8
,.*
! I
I 1 1
I
a
I
0
25
50
73
/00
Per
c/7?
02
'/lour
,otocx:oe/
order
SIC7/7/0//b/7
FIG.
1
4
The
upper
curve
represents
the
relation
between
the
duration
of
life
at
different
grades
of
intermittent
starva-
tion
with
water,
and
the
lower
one
represents
the
same
but
for
experiments
when
water
was
not
supplied.
The
period
of
transferring
the
fl
ies
from
food
in
empty
bot-
tles
was
equal
to
twenty-four
hours
fl
ies
being
kept
without
food
six,
twelve
and
eighteen
hours
which
we
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40
THE
AMERICAN
NATURALIST
[VOL.
LXIV
expressed
as
25
per'
cent.,
50
per
cent.
and
75
per
cent.
starvation.
The
curves,
which
fi
t
very
well,
particularly
the
left
portion
of
the
observed
points,
belong
to
the
type
of
logistic
curves.'
As
far
as
the
right-hand
portion
of
the
observed
data
is
concerned
(near
the
very
high
de-
gree
of
starvation)
there
is
not
sufficient
evidence
to
be
sure
that
there
is
here
a
trend
corresponding
to
the
branch
of
logistic
curve
with
a
decreasing
slope.
But
on
the
whole
these
curves
differ
entirely
from
the
expo-
nential
curve
which
represents
the
relation
of
duration
of
life
to
temperature
(Alpatov
and
Pearl,
110)
as
well
as
that
of
duration
of
life
and
density
of
population
(Pearl,
Miner
and
Parker,
117).
II
Our
present
investigation
is
to
be
considered
as
a
pre-
liminary
study
for
a
future
detailed
investigation
of
the
influence
of
nutrition
on
the
duration
of
life
of
Drosoph-
ila.
Our
material
is
based
on
three
independent
dura-
tion
of
life
experiments.
The
first
of
these
consisted
in
producing
small
size
fl
ies
by
taking
the
larvae
from
the
food
before
the
normal
end
of
larval
feeding
and
testing
their
longevity.
The
two
others
give
information
con-
cerning
the
duration
of
life
of
fl
ies
kept
on
synthetic
food
without
yeast,
and
the
influence
of
changing
food
every
day
as
compared
with
every
second
day.
The
preparation
of
the
material
for
the
fi
rst
experi-
ment
consisted
in
putting
0
-4
-hour
-old
larvae
collected
according
to
a
Method
previously
described
(108)
in
half-
pint
bottles
containing
100
cc
synthetic
medium,
with
yeast
planted
the
day
before.
One
hundred
larvae
of
wild
fl
ies
line
107
were
put
in
each
bottle.
The
larvae
were
kept
at
a
temperature
of
25°
C.
Thirteen
bottles
with
100
larvae
in
each
bottle
produced
1,033
adult
fl
ies
-
535
females
and
498
males.
That
means
that
79.5
per
cent.
of
the
larvae
reached
the
adult
stage,
the
number
3
The
method
used
to
fi
t
the
logistic
curves
is
described
by
Reed
and
Berk
-
son
(p.
767,
119).
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STUDIES
ON
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DURATION
OF
LIFE
41
of
males
being
equal
to
93.1
of
the
females.
The
control
fl
ies
emerging
from
normally
fed
larvae
were
placed
in
one
-ounce
duration
of
life
bottles,
fi
fteen
males
and
fi
fteen
females
in
each,
except
one
which
had
ten
males
and
twenty
females.
The
total
number
of
fl
ies
for
which
death
has
been
recorded
may
be
found
in
Table
III.
The
underfed
larvae
were
kept
in
the
same
way
as
the
normally
fed
until
they
had
fed
fi
fty-nine
hours.
At
that
time
they
were
taken
from
the
food
and
placed
in
bottles
with
plain
2
per
cent.
agar
-agar
washed
in
distilled
water.
The
mouths
of
the
bottles
were
covered
with
40
mm
watch
glasses
sealed
with
plasteline
until
the
moment
of
pupation
when
the
watch
glasses
were
again
replaced
by
the
usual
cotton
stopper.
This
was
done
to
prevent
the
larvae
from
crawling
out
as
they
are
apt
to
do
before
pupation.
Out
of
1,745
larvae
put
on
plain
agar
-agar
1,243
adult
fl
ies
emerged
-651
females
and
592
males
which
shows
that
out
of
fi
fty
-nine
-hour
-old
larvae
only
71.2
per
cent.
reached
the
fi
nal
stage.
In
other
words,
there
is
a
comparatively
high
mortality
among
the
larvae
unable
to
pupate.
The
males
were
equal
in
number
to
90.9
per
cent.
of
the
females.
.
The
same
density
in
dura-
tion
of
life
bottles
as
in
the
controls
was
used
for
under-
fed
flies,
except
in
one
bottle
where
thirteen
males
and
seventeen
females
were
kept
together,
and
two
others
with
thirty
females
each.
The
density
in
the
rest
of
the
bottles
was
fi
fteen
males
and
fi
fteen
females
per
bottle.
The
experience
of
this
institute
does
not
give
any
conclu-
sive
indications
about
the
influence
of
celibacy
on
dura-
tion
of
life.
Therefore
we
assume
the
right
to
include
in
our
life
table
calculations
the
records
of
these
sixty
females
kept
without
males.
Records
of
the
number
of
dead
males
in
fi
ve
bottles
and
of
females
in
three
bottles
were
larger
than
the
original
number
of
flies
put
in
the
bottles
in
the
beginning
of
the
experiments
and
were
therefore
discarded
from
the
calculations.
Food
was
changed
every
day
except
Sundays.
We
will
not
go
into
the
history
of
the
question
of
influence
of
underfeeding
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THE
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[Vol..
LXIV
of
larvae
upon
the
size
,
of
the
imago,
another
paper
(109)
being
partly
devoted
to
this
question.
III
Table
II
represents
the
basic
biometrical
constants
of
the
measurements
of
the
wing length
and
width
of
our
underfed
and
normally
fed
fl
ies.
The
measurements
were
made
according
to
the
scheme
described
before
(110).
Two
most
important
facts
have
to
be
emphasized.
First,
that
the
reduction
in
the
size
of
the
wing
is
much
more
pronounced
in
females
than
in
males.
It
can
be
judged
from
the
values
of
the
ratios
and
also
from
the
expression
of
the
length
of
wings
of
underfed
fl
ies
in
pro-
portion
to
the
length
of
wings
of
normally
fed
ones.
This
expression
for
females
is
equal
to
83.3
and
for
males
it
is
equal
to
92.0.
This
peculiarity
has
its
explanation
in
the
fact
that
the
difference
in
size
between
larvae
which
will
produce
males
and
females
becomes
more
and
more
pronounced
as
the
larvae
approach
the
pupal
stage.
In
other
words,
the
larvae
which
will
produce
males
are
closer
to
the
fi
nal
larval
size
at
a
given
moment
of
the
larval
life
than
the
larvae
which
will
become
female
imagoes.
Therefore,
younger
larvae
taken
from
the
food
produce
males
which
are
closer
to
normal
males
than
the
corresponding
females
to
normally
fed
females.
The
second
striking
difference
is
the
much
larger
vari-
ability
of
the
underfed
fl
ies.
This
greater
variation
of
experimental
fl
ies
is
in
accord
with
a
long
-known
fact
that
abnormal,
unfavorable
conditions
increase
the
varia-
tion
(see
Pearl,
116).
It
is
interesting
to
note
that
in
case
of
wing
width
the
underfed
males
have
even
broader
wings
than
the
corresponding
females.
The
sex
differ-
ence
between
the
underfed
fl
ies
is
almost
negligible
as
compared
with
that
in
normally
fed
fl
ies.
Tables
III
and
IV
and
Figs.
2
and
3
represent
the
results
obtained.
The
underfed
females
show
the
same
duration
of
life
as
the
control
ones.
The
males
show
a
longer
duration,
although
the
difference
is
statistically
not
very
signifi-
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TABLE
II
BIOMETRIC
CONSTANTS
OF
FLIES
DEVELOPED
FROM
UNDERFED
AND
NORMALLY
FED
LARVAE
IN
MILLIMETERS
Females
from
Difference
normally
fed
and
Ratio
larvae
Diff.
P.E.
Females
from
underfed
larvae
©
7,113
Mean
1.738
±
.005
.291
.013
1.447
±
.012
''':
AD
R
=22.4
crq
--
V.:"
o
Standard
deviation
.
.0398
.1246
H
O'
Coef-
q
Q,
l.
fi
cient
of
AD
'
variation
...
2.29
±
.21
8.61
LE
.
.60
o
T.,
,
ro..
-.4
N
25
47
n
©
2-.
Mean
.9969
±
.0030
.1844
±
.0076
.8125
±.0070
1
)
.
R=24.3
Standard
2s
a)
:,
-',,
deviation
.
.0223
.0709
---i
'
t;
Coef-
fi
cient
of
c
°
2
H,
.
,
--
-
variation
._
2.24
.21
8.73
±
.61
'
-
k-
-
,---
,,,
4
7
-
o
N
25
47
.9
w
>
AD
4
CM
P
CD
R
Males
from
normally
fed
larvae
Difference
and
Ratio
Diff.
P.E.
Males
from
underfed
larvae
1.532
.004
.123
±
.008
1.409
±
.007
R
=15.4
.0358
.0770
2.34
LE.
.18
5.46
LE
.
.37
40
50
.8962
-
±.0029
.0800
L
1
L
.0052
.8162
±
.0043
R
=15.4
.0270
.0447
3.01
±
.23
5.43±
-
.37
40
50
STUDIES
ON
THE
DURATION
OF
LIFE
44
THE
AMERICAN
NATURALIST
[VoL.
LXIV
/000
/00
/0
Underfed
b
larval
stage
d
Normally
f10
I
I
0
/5
.30
1/
5
60
/f
.
S7P
4?
days
FIG.
2
75
/000
/00
lamterced/t7larict
stage
Norma&
feel
/5
30
05
60
ZS
Age
ri?
days
FIG.
3
cant.
The
conclusion
which
may
be
drawn
is
that
in
spite
of
the
very
significant
reduction
in
size
(for
the
female
wing
length
16.7
per
cent.,
wing
width
18.5;
for
the
male
wing
length
8.0,
wing
width
8.9)
the
dura-
tion
of
life
remains
about
the
same.
Comparing
these
results
with
the
conclusions
drawn
in
a
paper
on
temper-
ature
(110)
where
it
was
shown
that
cold
flies,
character-
ized
by
larger
body
size,
have
at
the
same
time
a
greater
longevity
than
the
control
ones
(in
this
case
the
reduc-
tion
in
size
for
four
characters
was
for
males
equal
to
10.1
per
cent.,
and
to
7.8
for
females)
it
must
be
admitted
that
the
size
of
body
itself
is
not
the
fundamental
factor
determining
the
duration
of
life.
The
same
somatologi-
cal
effect
—reduction
of
body
size
—when
produced
by
different
factors
(in
our
fi
rst
case
by
temperature,
in
the
present
case
by
undernourishment)
gives
quite
different
results.
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STUDIES
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DURATION
OF
LIFE
45
TABLE
III
SURVIVORSHIP
DISTRIBUTION
AND
BIOMETRIC
CONSTANTS
OF
FLIES
UNDERFED
AND
NORMALLY
FED
IN
THE
LARVAL
STAGE
Days
Underfed
fl
ies
Normally
fed
fl
ies
Male
Female
Male
Female
0-
4
1,000
1,000 1,000
1,000
5-
9
987
976
989 989
10-14
979
967
975
981
15-19
949
950
945 965
20-24
887
935
897
960
25-29
782
886
814
928
30-34
646
803
593
846
35-39
.........
500
762
393
785
40-44
361
677
271
718
45-49
288
585
192
651
50-54
223
523
140
534
55-59
158
426
95
398
60-64
115
327
75
290
65-69
42
220
32
187
70-74.
6
128
7
69
75-79
0
19
0
21
80-84
0
0
Mean
37.11
±
.52
48.42
±
.54
34.59
.44
49.11
±
.50
Standard
devia-
tion
15.26
18.41
13.59
16.12
Coefficient
of
variation
41.12±
1.14
38.02
±-
.89
39.29
1.02
32.82
±
.79
Absolute
number
of
fl
ies
397
532
444
474
We
want
to
emphasize
the
danger
of
fallacious
conclu-
sions.
It
is
not
entirely
improbable
that
a
little
greater
duration
of
underfed
males
and
an
equal
duration
of
underfed
females
originated
as
a
result
of
a
certain
selec-
tive
process.
Only
the
strongest
larvae
succeed
in
the
struggle
for
life
without
a
sufficient
supply
of
food.
Table
IV
contains
also
some
indices
calculated
by
the
well-known
approximate
formula
recommended
by
Johannsen
(113,
p.
706).
There
is
a
slight
reduction
of
the
sex
differences
in
duration
of
life
among
underfed
fl
ies
as
compared
with
normal
ones.
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46
THE
AMERICAN
NATURALIST
[Vor.
LXIV
TABLE
IV
AVERAGES
AND
INDICES
OF
THE
DURATION
OF
LIFE
OF
FLIES
UNDERFED
IN
LARVAL
STAGE
AND
NORMALLY
FED
Underfed
in
larval
stage
Difference
and
Ratio
Normally
fed
in larval
stage
Average
duration
of
life
Average
duration
of
life
Female
...
48.42
±
.54
.69
±
.74
49.11
±
.50
R
=
.93
Male
37.11
±
.52
2.52
±
.68
34.59
±
.44
R
=
3.7
Indices
Male
76.65
±
1.37
6.22
±
1.79
70.43
±
1.15
R
=
3.5
Female
...
100
100
Male
107.30
-.
±
2.02
8.71
±
2.51
100
Female
...
98.59
±
1.49
R
=
3.5
100
IV
The
next
experiment
originated
from
a
purely
practi-
cal
question.
In
our
experiments
on
egg
production
of
the
fruit
-fly
we
used
the
synthetic
food
as
a
substratum
given
to
females
on
which
to
deposit
eggs.
To
strew
yeast
on
the
surface
was
a
great
nuisance
because
it
hampered
us
in
counting
the
eggs. We
finally
decided
to
put
some
drops
of
yeast
suspension
on
the
surface
of
the
synthetic
food.
But
the
question
whether
the
presence
of
yeast
influences
the
duration
of
life
of
adult
flies
yet
remained
unsolved.
The
question
is,
in
other
words,
whether
the
carbohydrates
available
in
synthetic
food
(the
new
synthetic
medium
contains
8.3
per
cent.
of
cane
sugar)
are
sufficient
to
keep
up
the
life
of
an
adult
Drosophila.
We
must
admit
that
the
experiment
was
not
perfect
from
one
point
of
view.
The
flies
used
came
from
ordi-
nary
room
temperature
mass
culture,
while
undoubtedly
it
would
be
much
more
desirable
to
work
with
fl
ies
devel-
oped
under
complete
absence
of
any
micro-organisms.
In
the
beginning
of
the
experiment
the
surface
of
the
food
in
bottles
without
yeast
remained
during
twenty
-
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STUDIES
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DURATION
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47
four
hours
just
as
shiny
as
at
the
moment
of
putting
the
fl
ies
in
the
bottles.
Toward
the
middle
of
the
experiment
there
could
be
observed
in
bottles
a
certain
kind
of
micro-
organism
growth.
But
this
slight
growth
was
entirely
different
from
the
usual
growth
of
yeast
on
the
surface
of
the
synthetic
medium.
The
flies
used
in
this
experiment
were
taken
from
wild
line
107
on
the
fifth
and
sixth
days
after
the
beginning
of
the
emergence
in
the
corresponding
bottles.
Naturally
their
age
at
the
moment
of
the
beginning
of
the
experi-
ment
was
equal
to
0-24
hours.
The
food
in
experimental
and
control
sets
of
bottles
was
changed
every
day
includ-
ing
holidays.
The
density
was
twenty-five
males
and
twenty-five
females
per
bottle.
In
the
series
kept
with-
out
yeast
we
included
also
a
bottle
with
thirty-two
females
kept
without
males,
and
a
bottle
with
fi
fty
females
which
were
put
without
males
according
to
the
record
taken
at
the
moment
of
starting
the
experiment,
/000
/000
gam
yeast
d
114th
yeas,
9
/00
/00
tOP701.0`
yeast
cf
/0
0
/5
30
45
60
75
/40' in
days
FIG.
4
/Who&
yeast
9
1 1 1
1 1
0
/5
30
4
,
5
60
75
Age
11
-
7
days
FIG.
5
L
SO
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THE
AMERICAN
NATURALIST
[VoL.
LXIV
but
according
to
the,
subsequent
observations
on
the
process
of
dying
out
it
turned
out
that
the
bottle
con-
tained
also
eight
males.
The
series
with
yeast,
besides
normally
populated
bottles
(twenty-eight
males
and
twenty-five
females),
includes
one
which
had
thirty-two
females
kept
separately,
and
another
which
had
twenty
females
and
twenty
males.
The
results
are
brought
together
in
Tables
V
and
VI
and
represented
graphically
on
Figs.
4
and
5.
It
can
be
seen
at
once
that
the
fl
ies
kept
without
yeast
live
a
much
TABLE
V
SURVIVORSHIP
DISTRIBUTION
AND
BIOAIETRIC
CONSTANTS
OF
FLIES
KEPT
ON
SYNTHETIC
FOOD
WITH
AND
WITHOUT
YEAST
Days
Food
without
yeast
Food
with
yeast
Male
Female
Male
Female
0-
4
1,000
1,000
1,000
1,000
5-
9
983
986
978
985
10-14
969
955
973
980
15-19
523
842
924
960
20-24
276
722
808
948
25-29
186
590
655
933
30-34
82
420 400
895
35-39
23
271
171
845
40-44
3
175
88
772
45-49
0
113
73
717
50-54
82
51
625
55-59
77
35
517
60-64
G3
27
412
65-69
27 27
289
70-74
15
22
171
75-79
7
8
71
80-84
5
3
23
85-89
0
0
5
90-94
0
Mean
17.725
±
.258
29.25
±-
-
.48
28.715
±
.417
53.24
±
1.80
Standard
devia-
tion
7.220
14.625
11.92
17.58
Coefficient
of
variation
40.73
-.
1.03
50.00
±
1.43
41.51
±
1.19
33.02
±
.87
Absolute
number
of
fl
ies
356
417
372
399
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STUDIES
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DURATION
OF
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49
TABLE
VI
AVERAOES
AND
SEX
INDICES
OF
TIIE
DURATION
OF
LIFE
OF
FLIES
KEPT
WITHOUT
YEAST
AND
WITH
YEAST
Without
yeast
Average
duration
of
life
Difference
and
ratio
With
yeast
Average
duration
of
life
Females
Males
29.25
±
0.48
17.725
±
0.258
23.99
±
1.90
R
=12.63
10.99
±
0.490
R
=
22.43
53.24
±
1.80
28.715
±
0.417
Indices
Indices
Males
60.60
±
1.33
6.66
±
2.39
53.94
±
1.98
R
=
2.79
Females
100 100
Males
61.73
±
1.26
6.79
±
2.41
100
Females
54.94
±
2.06
R
=
2.81
100
shorter
time
than
the
control
ones.
If
we
compare
the
sex
index
of
duration
of
life
(meaning
the
male
duration
of
life
expressed
in
per
cent.
of
the
female)
of
our
second
experiment
with
those
of
the
first
(underfed
and
nor-
mally
fed
fl
ies)
we
observe
that
in
the
former
the
index
is
significantly
higher
than
in
the
latter.
We
have
no
data
to
explain
this
difference,
leaving
it
for
further
investigation.
Up
to
the
present
time
most
of
the
authors
working
on
nutrition
of
fl
ies
have
concentrated
their
whole
attention
on
the
requirements
of
larvae
for
different
nutritive
sub-
stances.
Little
attention
has
been
paid
to
the
adult
form.
There
are
meager
data
published
by
Guyenot
(112),
Loeb
and
Northrop
(16),
Vinokuroff
(70)
and
Glaser
(75,
76).
The
fi
rst
of
these
authors
was
mainly
interested
in
the
influence
of
different
kinds
of
food
on
reproduction.
Loeb
and
Northrop
could
not
show
any
difference
be-
tween
the
duration
of
life
of
fl
ies
kept
on
glucose
-agar
with
yeast
and
without
it.
Vinokuroff
's
data
show
that
the
average
duration
of
life
of
fl
ies
kept
on
sugar
with
addition
of
peptone
is
higher
than
without
it
(22
days
against
17.6).
Glaser's
conclusions
based
on
a
very
small
number
of
experimental
animals
are
not
very
definite.
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THE
AMERICAN
NATURALIST
[VoL.
LXIV
His
statement
is:
,
"On
a
diet
of
sucrose
and
bouillon,
sucrose
and
blood
serum,
glucose
and
bouillon,
glu-
cose
and
blood
serum,
the
longevity
and
degree
of
egg
deposition
reach
their
maximum."
This
means
that
carbohydrates
alone
are
not
sufficient
for
adult
insects
which
live
longer
on
food
with
the
addition
of
proteins.
In
our
case
very
likely
such
proteins
have
been
supplied
by
the
growing
yeast
cells.
We
are
perfectly
well
aware
of
the
fact
that
a
whole
series
of
experiments
would
be
needed
to
clear
up
entirely
the
question
whether
the
pro-
teins
could
be
given
in
another
form
than
living
yeast
cells.
V
The
last
experiment
with
different
feeding
arose
as
a
side
issue
of
an
attempt
to
determine
the
influence
of
light
and
darkness,
as
well
as
of
intermittent
light,
on
the
duration
of
life
of
Drosophila.
All
three
groups
were
000
/00
Food
changed
every
second
day
naod
changed
every
day
a
0
/5
30
'/5
60
Age
in
days
I'm.
6
75
/000
/00
L-
r000'cionged
foodchanyedevery
o
second
day
9
/0
0
/5
30
445
60
75
Age
in
days
Pm.
7
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DURATION
OF
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51
kept
in
one
incubator
and
in
each
of
these
groups
half
of
the
bottles
were
changed
every
day
(except
Sunday)
and
the
other
half
three
times
a
week.
The
differences
in
duration
of
life
under
different
conditions
of
illumination
were
found
to
be
statistically
insignificant,
which
per-
mitted
the
combining
of
all
fl
ies
with
similar
conditions
of
food
changing,
and
the
comparison
of
their
duration
of
life
with
each
other.
The
density
in
this
experiment
was
twenty-five
males
and
twenty-five
females
per
bottle.
Tables
VII
and
VIII
and
Figs.
6
and
7
show
that
there
is
no
influence
on
female
duration
of
life
in
experimental
and
control
groups.
On
the
other
hand,
the
males
in
the
TABLE
VII
SUIIVIVORSIIIP
DISTRIBUTION
AND
BIOMETRIC
CONSTANTS
OF
FLIES
KEPT
ON
FOOD
CIIANGED
EVERY
DAY
AND
EVERY
SECOND
DAY
Days
Food
changed
every
day
Food
changed
every
second
day
Male
Female
Male
Female
0-
4
1,000
1,000
1,000
1,000
5-
9
996
997
999
998
10-14
992
992 992
993
15-19
950
981
970
984
20-24
836
967
938
978
25-29
722
936
878
961
30-34
491
802
701
848
35-39
280
750
601
791
40-44
173
715
538
756
45-49
86
677
447
686
50-54
59
598
329
571
55-59
38
538
228
468
60-64
20
378
92
251
65-69
12
200
43
101
70-74
0
84
2
24
75-79
21
1 1
80-84
0 0
0
Mean
30.775
0.274
50.68±0.42
41.295.±0.354
49.555
0.341
Standard
deviation
11.03
16.77
14.66
14.22
Coefficient
of
variation
35.84
±0.71
33.09±0.64
35.50
±.0.68
28.70
±0.52
Absolute
num-
ber
of
fl
ies
735
732
780
793
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52
THE
AMERICAN
NATURALIST
LVor..
LXIV
TABLE
VIII
AVERAGES
AND
INDICES
OF
THE
DURATION
OF
LIFE
OF
FLIES
KEPT
IN
BOTTLES
WITH
FOOD
CHANGED
EVERY
DAY
AND
EVERY
SECOND
DAY
Every
day
change
Average
duration
of
life
Every
second
day
change
Average
duration
of
life
Females
...
50.68
±
.42
1.125
0.54
49.555
±
.341
R=2.1
Males
30.775
±
.274
10.520
±
.448
41.295
±
.354
R
,
23.5
Males
60.72
±
.74
22.6
±
1.13
83.33
±
.92
R
=19.2
Females
...
100
100
Males
74.52
±
.92
27.75
±
1.43
100
Females
...
102.27
±
1.10
13,,
19.4
100
group
where
the
food
was
changed
every
day
show
a
very
low
longevity
as
compared
with
the
controls.
There
is
no
doubt
about
the
statistical
significance
of
this
differ-
ence
in
this
particular
experiment.
It
is
remarkable
that
the
duration
of
life
sex
index
is
extremely
high
for
the
males
in
the
control
group. Even
if
we
compare
the
male
mortality
in
the
group
in
which
the
food
was
changed
every
day
with
the
control
group
of
our
fi
rst
experiment,
and
with
fl
ies
normally
fed
in
the
larval
stage,
the
differ-
ence
remains
significant,
showing
exceptionally
low
duration
of
life
of
males
in
case
the
food
is
changed
every
day.
Discussing
the
previous
experiment
we
tried
to
point
out
that
yeast
plays
an
important
role
in
prolongation
of
the
life
of
Drosophila
melanogaster.
Very
likely
it
is
not
the
dry
yeast
cells
which
are
eaten
by
the
fl
ies
but
fresh
yeast
growth
which
appears
in
abundance
particularly
twenty-four
hours
after
the
preparation
of
the
food.
Changing
the
food
every
day
we
evidently
kept
our
ex-
perimental
fl
ies
on
a
kind
of
intermittent
partial
starva-
tion,
depriving
them
of
luxuriantly
grown
yeast
colonies.
This
is
one
of
the
most
plausible
explanations
of
the
shorter
duration
of
males
on
food
changed
every
day.
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STUDIES
ON
THE
DURATION
OF
LIFE
53
Why
the
female
did
not
show
the
same
effect
can
be
per-
haps
answered
by
taking
into
account
the
differences
in
female
constitution
and
physiology.
The
fat
body,
which
represents
the
place
of
storing
the
nutritive
substances
in
insect
organisms,
is
much
better
developed
in
females
than
in
males.
Besides
that,
the
egg
-producing
activity
in
females
must
react
quite
differently
to
the
same
ex-
ternal
factor
which
fi
rst
seemed
to
be
responsible
for
the
reduction
of
male
life
in
case
of
every
day
change.
A
question
may
arise
whether
the
effect
is
due
to
the
influ-
ence
of
a
purely
mechanical
shaking,
which
takes
place
much
more
often
in
the
group
changed
every
day
as
com-
pared
with
the
controls.
This
difference
must
be
par-
ticularly
pronounced
in
the
beginning
of
the
experiment.
Afterwards
the
taking
out
of
dead
fl
ies
even
without
changing
food
requires
shaking
them
out
and
back.
We
do
not
think
this
factor
is
to
be
taken
into
very
serious
consideration
because
the
handling
of
the
fl
ies
has
been
done
by
ourselves
(W.
W.
A.)
with
extreme
care
and
attention.
On
the
other
hand,
against
the
possibility
of
such
an
explanation
is
the
fact
that
the
whole
span
of
life
of
control
fl
ies
is
much
longer
than
that
of
the
experi-
mental
fl
ies,
showing
that
the
process
of
dying
was
going
differently
all
the
time
even
when
the
difference
in
fre-
quency
of
shaking
the
bottles
belonging
to
the
two
groups
disappeared
almost
entirely.
SUMMARY
Summarizing,
it
has
been
shown
in
this
paper
that
:
(1)
The
relation
between
the
duration
of
life
and
dif-
ferent
factors
is
expressed
by
quite
different
types
of
curves.
Temperature
and
duration
of
life
are
connected
by
a
simple
exponential
curve,
while
starvation
(data
from
KopeC)
and
duration
of
life
at
different
grades
of
intermittent
starvation
can
be
represented
by
the
upper
part
of
a
logistic
curve.
(2)
Drosophila
females
emerged
from
larvae
taken
from
the
food
before
the
end
of
the
normal
larval
feed
-
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54
THE
AMERICAN
NATURALIST
[VoL.
LXIV
ing
do
not
differ
in
their
duration
of
life
from
the
con-
trols.
The
males
show
even
a
longer
(although
statisti-
cally
not
very
significant)
duration
of
life
as
compared
with
the
controls.
This
shows
that
a
reduction
in
body
size
does
not
lead
inevitably
to
a
reduction
of
the
dura-
tion
of
life,
as
has
been
the
case
with
"room"
and
"cold"
temperature
fl
ies
which
differed
in
size
of
the
body
and
of
the
duration
of
life.
(3)
Keeping
fl
ies
on
synthetic
food
with
yeast
and
without
it
indicates
that
absence
of
yeast
reduces
greatly
the
duration
of
life
of
males
and
females.
Very
likely
the
carbohydrates
available
in
the
synthetic
food
are
not
sufficient
for
nutrition
of
adult
Drosophila,
and
addi-
tional
substances
included
in
living
yeast
cells
are
required.
(4)
Changing
synthetic
food
with
yeast
every
day
and
every
second
day
indicates
that
the
female
duration
of
life
is
not
affected
by
this
procedure,
while
males
in
this
experiment
show
a
much
shorter
duration
of
life
when
transferred
to
new
bottles
every
day.
This
difference
may
perhaps
be
attributed
to
sex
differences
in
metabo-
lism,
or
food
requirements
of
male
and
female
organism.
Every
day
food
changing
can
possibly
be
considered
as
a
partial
starvation,
because
yeast
shows
growth
only
after
twenty-four
hours,
and
changing
food
every
day
does
not
permit
the
fl
ies
to
have
yeast
growth
in
such
abundance
as
in
the
case
when
the
bottles
are
changed
every
second
day.
It
is
also
possible
that
the
results
for
the
males
in
this
particular
experiment
are
not
typical.
LITERATURE
CITED
(The
plan
of
numbering
citations
is
explained
in
the
second
of
these
studies,
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NATURALIST,
56:
174.)
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Alpatov,
W.
W.,
"Growth
and
Variation
of
the
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of
Drosophila
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of
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Vol.
52,
No.
3,
pp.
407-432,
1929.
109.
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and
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Size
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Drosophila
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subject
to
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of
Chicago
Press
Terms
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(http://www.journals.uchicago.eduk-an
No.
690]
STUDIES
ON
THE
DURATION
OF
LIFE
55
110.
Alpatov,
W.
W.,
and
Pearl,
Raymond,
"Experimental
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on
the
Duration
of
Life.
XII.
Influence
of
Temperature
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the
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NATURALIST,
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E.,
Carpenter,
F.
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A.
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L.,
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Johannsen,
W.,
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Kopec,
Stefan,
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On
the
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204-211,
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Northrop,
J.,
"The
Influence
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the
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Pearl,
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AMERICAN
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Phillips,
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The
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Reed,
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ecisapic
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This
content
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