The longevity of plants - Die Lebensdauer der Pflanze


Molisch, H.; Fulling, E.H.

Duration of life in plants Die Lebensdauer der Pflanze 168 p

1929


The subject of longevity of living organisms presents an exceedingly important biological problem. In a variety of ways it touches upon so many phenomena of life and of biology in general that it provokes common scientific interest even beyond the realm of physiology itself. Strange to say, no comprehensive study upon the subject has heretofore been made. Jessen's worthy contribution "Über die Lebensdauer der Gewächse," which appeared 65 years ago, did not consider the subject in its entirety but dealt with only one though very significant aspect. It was concerned primarily with the question as to whether asexually propagated seed-plants possess an unlimited tenure of life, terminated only by accident or other unfavorable circumstances, or whether their longevity is inherently limited. Other problems associated with longevity were disregarded. A careful study of the subject among both lower and higher plants was neglected and no consideration was accorded such matters, among others, as senescence, developmental changes, the death of cells and tissues in the tree, nor the possibility of curtailing or prolonging life. Only recently has interest been focussed upon the problem, particularly by Weismann's ideas with respect to perpetual life among unicellular organisms. Many zoologists have worked upon this problem and in 1924 Korschelt2 gave us an excellent summary of the understanding which prevailed at that time of longevity, senescence and death among animals. In this work longevity among plants is only incidentally considered. For the most part, Korschelt's meritorious work is concerned almost exclusively with animals and in view of this there is need of a detailed and comprehensive consideration of the subject from the botanical standpoint.

THE
LONGEVITY
OF
PLANTS
(Die
Lebensdauer
der
Pflane)
BY
DR.
HANS
MOLISCH
Director
of
the
Institute
of
Plant
PhysiologY
of
the
University
of
Vienna
Authorized
English
Edition
BY
EDMUND
H.
FULLING
Co-founder,
Manager
and
Editor
of
The
Botanical
Review
PUBLISHED
BY
THE
TRANSLATOR
NEW
YORK
1938
CONTENTS
PREFACE
TO
ENGLISH
EDITION
3
5
FOREWORD
7
INTRODUCTION
CHAPTER
I
THE
LONGEVITY
OF
UNICELLULAR
ORGANISMS
9
PERPETUAL
LIFE
OF
UNICELLULAR
ORGANISMS
.
.
.
9
ARE
ALL
UNICELLULAR
ORGANISMS
ENDOWED
WITH
PERPETUAL
LIFE?
14
Zooprotistans
14
Diatoms
16
Other
Unicellular
Algae
18
Yeasts
19
Summary
20
LENGTH
OF
GENERATION,
DAILY
PROGENY,
INDIVIDUAL
LONGEVITY
21
Bacteria
22
Yeasts
22
Peridiniidae
25
Diatoms
25
Desmids
27
Flagellates
28
Summary
28
CHAPTER
II
THE
LONGEVITY
OF
MULTICELLULAR
ORGANISMS
30
CRYPTOGAMS
31
Algae
31
Fungi
32
Mosses
35
Pteridophytes
k
38
Ferns
38
Lycopodium
39
PHANEROGAMS
39
Gymnosperms
40
Coniferae
40
Gnetaceae
52
Angiosperms
53
Monocotyledons
53
Dicotyledons
56
Summary
74
CHAPTER
III
LONGEVITY
AND
RELATED
PHENOMENA
.
.
79
VARIOUS
PERIODS
OF
LONGEVITY
AND
THEIR
PROBABLE
_CAUSES
79
LONGEVITY
AND
SYSTEMATIC
RELATIONSHIP
86
Individuals
of
the
Species
86
Species
of
a
Genus
86
Genera
of
a
Family
and
the
Higher
Groups
.
87
UNLIKE
PERIODS
OF
LONGEVITY
OP
THE
Two
SEXES
88
THE
LONGEVITY
OF
ORGANS
91
Flowers
91
Leaves
95
Pteridophytes
96
Gymnosperms
96
1
2
CONTENTS
Monocotyledons
97
Dicotyledons
98
Summary
99
Continued
Increase
of
Ash
Content
as
a
Contributing
Factor
in
the
Death
of
Leaves
103
Hair
109
THE
DEATH
AND
LONGEVITY
OF
TISSUE
CELLS
110
Pith
110
Wood
114
Cortex
r
117
Stomata
117
Roots
118
Leaves
118
Flowers
120
Pollen
120
Isolated
Cells
121
Summary
121
CHAPTER
'IV
THE
MEANS
OF
PROLONGING
THE
LIFE
OF
PLANTS
123
EXCLUSION
OF
ALL
ADVERSITIES
123
TEMPORARY
REMOVAL
OF
THE
INDISPENSABLE
CONDITIONS
OF
LIFE
124
PREVENTION
OF
FLOWERING
AND
FRUITING
125
PREVENTION
OF
POLLINATION
AND
FERTILIZATION
130
EXTENDED
PERIOD
OF
FUNCTIONING
131
MISCELLANY
134
REVIEW
142
CHAPTER
V
REJUVENESCENCE
144
CHAPTER
VI
APPARENT
DEATH
151
THE
CONCEPT
OF
APPARENT
DEATH
151
LIFE
REACTIONS
153
THE
OCCURRENCE
OF
APPARENT
DEATH
155
Animals
155
Liverworts
156
Mosses
156
Algae
157
Fungi
157
Seeds
157
TEMPORARY
COMPLETE
INTERRUPTION
OF
LIFE
162
CHAPTER
VII
OLD
AGE,
DEATH
AND
THE
ALLEGED
POTENTIAL
PER—
PETUAL
LIFE
OF
THE
TREE
165
OLD
AGE
AND
DEATH
165
IS
THE
TREE
POTENTIALLY
ENDOWED
WITH
PERPETUAL
LIFE?
175
BIBLIOGRAPHY
195
FROM
THE
GERMAN
EDITION
OF
"DIE
LEBENSDAUER
DER
rFLANZE"
195
FROM
MORE
RECENT
LITERATURE
CONCERNING
LONGEVITY
AND
RELATED
SUBJECTS
211
INDEX
TO
AUTHORS
217
INDEX
TO
SUBJECT
MATTER
221
TRANSLATOR'S
PREFACE
Acknowledgements,
to
the
reader,
may
appear
as
useless
addenda,
but
to
the
writer
they
are
the
humble
expression
of
an
inescapable
conviction
that
without
the
assistance
of
his
colleagues
this
translation
would
not
have
borne
fruition,
or
at
least,
would
have
entailed
greater
difficulties.
It
is
in
this
spirit
that
I
gratefully
recognize
the
assistance
of
Dr.
A.
B.
Stout
who
directed
the
at-
tention
of
the
writer
to
this
-
work
of
Dr.
Molisch,
and
who
read
the
entire
translation
;
to
Dr.
J.
H.
Barnhart
for
his
ever
-willing
council
in
bibliographical
matters;
and
to
Mrs.
A.
S.
Linton
for
her
checking
of
the
entire
translation
and
for
other
details
in
completing
th
volume.
Thanks
areOdue
particularly
to
Dr.
Barnhart
who
painstakingly
verified
or
corrected
every
citation
in
the
bibliography
of
the
Ger-
man
edition,
so
far
as
was
at
all
possible,
and
in
most
cases
aug-
mented
the
original
and
usually
incomplete
forms
in
which
they
were
presented.
EDMUND
H.
FULLING
FOREWORD
Reports
of
observations
concerning
longevity,
senescence
and
death
among
plants
are
so
scattered
in
the
literature,
frequently
in
such
inaccessible
places,
that
it
is
difficult
to
orient
oneself
prop-
erly
in
the
various
aspects
of
the
important
problems
of
natural
science
which
are
involved.
Because
of
this
situation
I
undertook;
ten
years
ago,
to
study
the
longevity
of
plants
from
various
view-
points
and
to
gather
the
known
facts,
with
necessary
revisions,
into
a
monograph
of
the
problem
as
it
concerns
the
entire
plant
kingdom.
In
1921
the
foundation
for
this
proposed
book
had
already
been
completed
in
outline
but
my
appointment
at
the
Imperial
University
of
Sendai
in
Japan
interrupted
its
completion.
Other
duties
dur-
ing-
my
almost
three
year
visit
in
the
Land
of
the
Rising
Sun
so
occupied
my
attention
that
the
manuscript
had
to
be
laid
aside
and
could
not
be
completed
until
my
return
to
available
sources
of
the
latest
literature
and
research
upon
the subject.
I
now
hope
I
have
produced
a
small
contribution
that
will
be
a
welcome
supple-
ment
to
E.
Korschelt's
excellent
book,
"Lebensdauer,
Altern
und.
Tod."
While
Korschelt's
work
is
concerned
with
the
longevity
pri-
marily
of
animals
and
only
secondarily
with
that
of
plants,
my
work
is
devoted
especially
to
an
account
of
longevity
among
plants
without,
however,
entirely
neglecting
the
general
aspects
of
the
problem
as
they
apply
to
animals.
Before
concluding
this
foreword,
I
wish
to
thank
my
assistant,
Dr.
J.
Kisser,
for
his
preparation
of
certain
illustrations
and
for
correcting
proof
which
I
was
unable
to
do
myself
because
of
my
call
to
India.
My
thanks
are
extended
to
Dr.
W.
Frenzel
who,
too,
carefully
examined
the
proof.
My
esteemed
publisher,
G.
Fischer
of
Jena,
willingly
cooperated
as
always
and
made
great
efforts
toward
a
satisfactory
completion
of
this
little
work.
To
him
also
I
extend
my
sincere
thanks.
HANS
MOLISCH
VIENNA,
OCTOBER,
1928
5
INTRODUCTION
The
subject
of
longevity
of
living
organisms
presents
an
exceed-
ingly
important
biological
problem.
In
a
variety
of
ways
it
touches
upon
so
many-therrarrrtrr
lant
life
and
of
biology
in
general
that
it
provokes
common
scientific
interest
even
beyond
the
realm
of
physiology
itself.
Strange
to
say,
no
comprehensive
study
upon
the
subject
has
heretofore
been
made.
Jessen's
worthy
contribution,
1
"
-
Ober
die
Lebensdauer
der
Gewiichse,"
which
appeared
65
years
ago,
did
not
consider
the
subject
in
its
entirety
but
dealt
with
only
one
though
very
significant
aspect.
It
was
concerned
primarily
with
the
ques-
tion
as
to
whether
asexually
propagated
seed
-plants
possess
an
un-
limited
tenure
of
life,
terminated
only
by
accident
or
other
un-
favorable
circumstances,
or
whether
their
longevity
is
inherently
limited.
Other
problems
associated
with
longevity
were
disre-
garded.
A
careful
study
of
the
subject
among
both
lower
and
higher
plants
was
neglected
and
no
consideration
was
accorded
such
matters,
among
others,
as
senescence,
developmental
changes,
the
death
of
cells
and
tissues
in
the
tree,
nor
the
possibility
of
cur-
tailing
or
prolonging
life.
Only
recently
has
interest
been
focussed
upon
the
problem,
par-
ticularly
by
Weismann's
ideas
with
respect
to
perpetual
life
among
unicellular
organisms.
Many
zoologists
have
worked
upon
this
problem
and
in
1924
Korschelt
2
gave
us
an
excellent
summary
of
the
understanding
which
prevailed
at
that
time
of
longevity,
senes-
cence
and
death
among
animals.
In
this
work
longevity
among
plants
is
only
incidentally
considered.
For
the
most
part,
Kor-
schelt's
meritorious
work
is
concerned
almost
exclusively
with
ani-
mals
and
in
view
of
this
there
is
need
of
a
detailed
and
comprehen-
sive
consideration
of
the
subject
from
the
botanical
standpoint.
7
CHAPTER
I
THE
LONGEVITY
OF
UNICELLULAR
ORGANISMS
PERPETUAL
LIFE
OF
UNICELLULAR
ORGANISMS
The
need
for
an
intensive
study
of
longevity
has
been
partially
fulfilled
already
in
zoological
and
botanical
writings,
especially
by
those
of
Doflein'
and
Kiister.
4
Doflein
was
concerned,
however,
not
so
much
with
longevity
itself,
but
rather,
as
the
title
of
his
book
indicates,
with
the
problem
of
death
and
perpetual
life
among
both
plants
and
animals.
Kiister
presented
a
short
survey
of
senes-
cence
and
death,
almost
entirely
as
it
concerns
plants,
in
a
con-
tribution
which
evolved
from
a
preliminary
report
upon
the
sub-
ject.
And
Weber's
5
concise
but
very
desirable
physiological
re-
view
of
the
phenomena
accompanying
senescence
has
also
furnished
a
welcome
contribution.
In
spite
of
these
valuable
works,
however,
there
is
lacking
a
monographic
study
of
longevity
among
plants
and
of
the
associated
many-sided
questions
concerning
senescence
and
death.
In
the
following
discu.ssion,
therefore,
an
attempt
will
be
made
to
meet
this
need
and
to
gather
together
in
a
critical
fashion
the
pertinent
and
widely
scattered
contributions
upon
each
phase
of
the
subject.
It
was
generally
believed,
not
so
long
ago,
that
every
organism
must
perish
at
some
time.
For
most
multicellular
organisms
this
conception
still
holds
true,
but not
in
the
case
of
most
unicellular
forms.
Weismann
6
performed
the
great
service
of
calling
attention
to
the
fact
that
while
we
customarily
associate
a
residual
dead
body
with
our
conception
of
death,
in
the
case
of
asexual
propagation
of
infusorial
organisms
by
mere
cell
division
the
entire
mother
-cell
is
transformed,
without
residue,
into
two
daughter
-cells.
The
mother
-
cell
divides
into
two
almost
identical
parts,
equivalent
in
appear-
ance
and
constitution.
Each
of
these
halves
continues
to
live
in
the
same
manner
as
did
the
mother
-cell
and
eventually
divides
in
its
turn.
This
led
WeismannT
to
conclude
"that
the
limitations
imposed
upon
an
individual
cell
by
death
are
not,
as
previously
assumed,
unavoidable
and
inherent
attributes
of
its
nature,
but
rather
perform
a
definite
function
and
are
called
forth
only
when
9
10
THE
LONGEVITY
OF
PLANTS
certain
complications
in
the
development
of
l
the
organism
would
tend
to
interfere
with
its
natural
tendency
to
live
forever."
As
with
so
many
other
great
truths,
this
one,
too,
has
hot
entirely
escaped
refutation.
The
zoologist
Wedekind
8
has
been
most
pro-
nounced
in
opposing
this
teaching
of
Weismann,
though
with
in-
adequate
foundation
for
his
contentions.
In
his
opinion,
there
is
no
basis
for
Weismann's
premise
that
unicellular
organisms
.divide
into
two
identical
parts.
They
only
appear
to
do
so,
he
contends,
and,
consequently,
among
single
cells
as
well
as
elsewhere,
we
can
speak
in
every
case
of
mother-
and
daughter
-cells.
The
mother
-
cell
is
capable,
he
admits,
of
dividing
again,
indeed
repeatedly,
but
eventually
it
must
perish.
Were
I
also
to
concede
that
in
many
cases
the
resulting
halves
of
multiplying
cells
are
not
equivalent,
as
I
shall
show
is
true
of
certain
unicellular
plants,
it
still
remains
for
Wedekind
to
prove
that
the
two
halves
are
not
equivalent
in
every
case
and
that
the
mother
-cell
is
not
capable
of
dividing
ad
infinitum.
No
one
has
yet
shown
that
the
halves
of
dividing
bac-
teria
are
not
alike
and
the
same
holds
true
for
many
other
unicellu-
lar
organisms.
The
facts
in
every
case,
therefore,
do
not
support
Wedekind's
refutation
of
Weismann's
conception.
Other
objections,
based
upon
experimental
grounds,
are
better
founded.
The
question
has
been
asked,
Can
protozoa
really
un-
dergo
an
unlimited
number
of
successive
divisions
or
do
they
fi
nally
perish,
perhaps
after
a
certain
number
of
generations?
Maupas
9
was
able
to
show
by
his
cultures
of
various
'species
of
ciliated
in-
fusoria
that
these
organisms
suffered
marked
changes
in
appear-
ance
and
behavior
as
the
result
of
long-cOntinued
breeding.
After
undergoing
100
to
300
divisions,
the
cells
began
to
absorb
less
nutri-
ment,
became
smaller,
lost
a
portion
of
their
cilia
and
fi
nally
suc-
cumbed.
On
the
basis
of
these
observations,
Maupas
opposed
the
ideas
of
\\Teismann
and
defended
the
view
that
the
unicellular
organism
is
not
endowed
with
unlimited
tenure
of
life
but
fi
nally
becomes
exhausted
and
perishes.
For
further
investigations
along
this
line
we
are
indebted
to
Calkinsi°
and
to
Hertwig.
During
the
course
of
15
months
Calkins
secured
more
than
500
generations
of
the
infusorian,
Paramecium
caudatum,
and,
after
90
to
170
divisions,
-found
changes
in
the
progeny
similar
to
those
observed
by
Maupas.
These
changes,
constituting
what
Calkins
called
the
"depression
condition,"
fi
nally
UNICELLULAR
ORGANISMS
11
led
to
death.
The
"depression"
can
be
alleviated,
however,
in a
variety
of
ways,
as
by
conjugation,
agitation,
and
changes
in
the
temperature
or
composition
of
the
nutrient
solution.
According
to
Calkins,
the
"depression
condition"
constitutes
a
part
of
the
de-
velopmental
cycle
and
represents
a
phase
in
the
life
of
infusoria
controlled
by
internal
factors.
g
na-e
Hertwi
has
professed
a
similar
idea.
He
studied
principally
the
changes
in
protista
cells
resulting
from
continued
asexual
propagation
and
regarded
the
concomitant
alterations
between
pro-
toplasmic
and
nuclear
masses,
i.e.,
the
nucleo-plasma
ratio,
as
the
controlling
factor.
If
the
normal
relation
between
nucleus
and
cytoplasm
is
disturbed,
there
results,
he
says,
hypertrophy
of
the
nucleus
and
development
of
all
those
phenomena
which
constitute
Calkins'
"depression
condition."
Conjugation
re-establishes
the
normal
relation
and
without
it
death
would
ensue.
Hertwig
also
believes
that
single
cells
do
not
possess
perpetual
life
but
that
death
is
an
inevitable
result
of
life
processes.
It
appears,
then,
as
if
Weismann's
views
had
been
invalidated.
The
subsequent
breeding
results
of
the
American
investigator
Woodruff,"a
-
d
however,
placed
the
works
of
Maupas,
Calkins,
and
Hertwig
in
an
entirely
different
light
and
upheld
to
a
great
degree
the
teaching
of
Weismann
concerning
perpetual
.
life
of
unicellular
organisms.
Woodruff
began
with
a
single
Paramaecium
caudatum,
secured
from
an
aquarium,
and
in
the
course
of
seven
years
bred
therefrom
4500
generations
in
concave
slides.
Altogether,
since
1907,
he
has
secured
8000
generations
without
conjugation
playing
any
part,
for
newly
formed
cells
were
always
transferred
to
a
fresh
.putrient
solution.
Under
these
conditions
there
appeared
no
de-
generation
or
-depression
and
the
daily
number
of
divisions,
except
for
certain
rhythmic
fl
uctuations'
which
need
not
be
discussed
here
in
detail,
remained,
after
thousands
of
generations,
the
same
as
in
the
beginning.
It
is
particularly
important
in
such
investigations
that
the
prog-
eny
always
be
transferred
to
a
fresh
nutrient
solution.
Otherwise,
the
accumulation
,of
secreted
assimilation
products
causes
those
disturbances
which
constituted
the
degeneration
observed
by
Maupas,
Calkins,
and
Hertwig.
If
the
accumulation
of
such
prod-
ucts
be
avoided
by
constant
change
of
solution,
then,
as
Woodruff
12
THE
LONGEVITY
OF
PLANTS
has
shown,
thousands
of
generations
can
bei
secured
by
division
alone
without
recourse
to
conjugation.
And
in
this
way
the
justifi-
cation
of
Weismann's
belief
in
the
perpetual
life
of
unicellular
forms
is
established.
The
mutual
influence
exerted
among
organisms
by
their
secre-
tion
products
is
of
considerable
significance."
I
refer
to
the
rela-
tion
between
host
and
parasite,
and
to
the
influence
of
bacteria,
yeasts
and
molds
upon
the
substratum.
The
production
of
either
growth
-inhibiting
or
growth
-promoting
substances
may
be
involved
and
the
former
may
accumulate
to
such
an
extent
that
further
de-
velopment
is
inhibited,
a
pathological
condition
occurs
and
fi
nally
the
organism
dies.
This
sequence
fulfills
the
remark
of
Duclaux'
5
when
he
says
"that
the
medium
which
the
microbe
creates
for
itself
becomes
less
and
less
nutritive
and
more
and
more
antiseptic."
Only
recently
have
we
come
to
realize
that
their
own
secretions
are
responsible
for
diminishing
activity
among
infusoria.
This
is
all
the
more
surprising
because
every
bacteriologist
has
long
been
familiar
with
the
products
of
bacterial
growth,
of
pigment
forma-
tion
and
of
luminescence,
which
accumulate
in
the
substratum
despite
a
sufficient
supply
of
nutriment.
If
colonies
of
luminous
bacteria
are
too
dense,
for
instance,
they
remain
small,
not
only
because
they
deprive
one
another
of
food
but
by
virtue
of
the
mutu-
ally
inhibiting
effects
of
their
secretions.
Even
if
we
permit
only
a
single
colony
to
develop
on
a
moderately,'
nutritious
substratum,
it,
too,
fi
nally
ceases
to
grow
and
to
glow
because
the
secretions,
despite
abundant
available
food,
inhibit
these
two
functions.
Richter
16
was
able
to
make
similar
observations,
in
connection
with
his
pure
cultures
of
diatoms.
Upon
his
own
as
well
as
Bei-
jerinck's
fi
ndings,
he
concluded
"that
all
algae,
cultivated
in
great
quantities
within
limited
confines,
show
effects
attributable
only
to
secretion
substances
which
are
poisonous
to
the
cells
and
which
hinder
their
increase
and
growth.
The
need
for
frequent
transfer-
ence
of
the
material
being
studied
is
thus
self
-apparent."
Para-
maecia
are
in
no
wise
different
but
act
in
accordance
with
this
gen-
eral
behavior.
To
return
now
to
the
question
of
perpetuahlife
among
infusoria,
it
is
apparent
that
conjugation
is
not
necessary
in
an
uninterrupted
succession
of
even
several
thousand
generations
but
that
it
does
UNICELLULAR
ORGANISMS
13
serve
to
prevent
degeneration
which
would
ensue
under
unfavorable
culture
conditions.
There
are
also
certain
unicellular
organisms
which
are
not
at
all
capable
of
conjugating
but
which
reproduce
exclusively
by
cell
division,
i.e.,
wholly
asexually.
Among
them
are
bacteria
and
the
blue-green
algae
or
Cyanophyceae.
Without
question,
these
may
be
regarded
as
being
endowed
with
everlasting
life
in
the
sense
of
Weismann.
In
addition,
a
great
many
unicellular
algae
and
fungi
are
known
which,
like
the
infusoria,
perpetuate
themselves
by
con-
jugation
as
well
as
by
cell
division.
That
they
are
capable
of
main-
,
taining
their
kind
by
asexual
means
alone
is
indeed
very
likely
but
as
yet
unproven.
It
would
be
very
desirable,
therefore,
if
propa-
gating
experiments
with
these
organisms
were
pursued
similar
to
those
which
already
have
been
carried
out
with
Parainaecium.
Such
experiments
might
easily
be
conducted
upon
desmids
and
in
all
probability
they
would
show
the
same
results
as
have
those
with
infusoria.
As
Woodruff
did
with
infusoria,
so
has
Hartmann''
performed
propagating
experiments
with
a
green
colony
-forming
fl
agellate,
Eudorina
elegans,
which
reproduces
only
asexually.
Hartmann
was
able
to
pursue
these
experiments
for
ten
years
and
claims
to
have
secured
more
than
3000
generations
by
purely
asexual
repro-
duction
at
a
constant
rate
of
division
and
without
evidence
of
any
ill
effects
upon
either
the
nuclei
or
the
cells
themselves.
In
view
of
this,
we
may
attribute
perpetual
life
in
Weismann's
sense
to
these
green
fl
agellates
also.
Belar
obtained
identical
results
with
a
zooprotistan,
Actinophrys
sol,
during
fi
ve
years'
work.
Considerable_interest
attaches
to
the
fact
that
similar
results
can
be
secured
with
certain
lower
multicellular
animals
which
are
capable
of
asexual
multiplication
by
division
and
by
budding.
Goetsch
and
Gross
were
able
to
propagate
our
common
fresh-
water
polyp
in a
purely
asexual
manner
for
years
at
a
time
and
at
a
constant
rate
when
kept
under
uniform
conditions.
Hartmann
secured
similar
results
with
a
certain
planarian,
Stenostomion,
as
did
Hammerling
with
the
oligochaete,
Aelosoma,
without
evidence
of
physiological
decadence
if
only
the
same
favorable
conditions
were
uniformly
provided.
14
THE
LONGEVITY
OF
PLANTS
ARE
ALL
UNICELLULAR
ORGANISMS
ENDOWED
WITH
PERPETUAL
LIFE?
Zooprotistans—Weismann's
conception
of
perpetual
life
among
unicellular
organisms
is
frequently
represented
as
to
imply
that
all
single
-celled
forms
are
so
endowed.
Such
generalization
is,
of
course,
unjustified.
Hertwig
and
Korscheles
have
already
noted
this
in
the
case
of
animals
and
I
shall
show
that
it
pertains
also
to
plants.
Hertwig
called
attention
to
the
decline
of
the
larger
part
of
the
nucleus
during
cyst
formation
among
the
heliozoa
and
re-
fers
to
such
processes
as
"partial
death"
among
unicellular
organ-
isms.
Among
other
protozoa,
as
in
the
case
of
Noctiluca,
a
part
of
the
cell
body
remains
as
a
lifeless
residuum
after
formation
of
a
great
number
of
swarm
spores.
In
the
case
of
certain
protozoa
which
are
provided
with
a
shell,
various
portions
of
the
cell
degen-
erate.
Korschelt
brought
this
out
and
remarks
"that
these
parts
may
no
longer
be
of
service
in
cell
division
and
though
employed
for
whatsoever
purpose
during
normal
vegetative
life,
they
have
served
their
function
and
are
discarded
by
the
animal,
as
is
true
also
of
the
eyelash
and
other
parts
of
the
body."
The
newer
investigations
with
protista
have
shown
that
lifeless
bodies
may
actually
appear,
even
resembling
the
cells
in
form.
This
is
particularly
true
during
reproduction
of
larger
multinucleate
forms
when
they
break
up
into
a
number
of
uninucleate
reproduc-
tive
bodies
corresponding
to
the:
original
number
of
nuclei.
That
death
ensues
upon
such
continual
vegetative
propagation
is
espe-
cially
well
shown
by
the
multinucleate
radiolarians
whose
form
and
structure
are
so
remarkable.
Their
marvelous
organization
is
de-
stroyed
and
certain
nuclei
and
portions
of
the
individuals
become
lifeless.
This
is
true
of
all
protista
with
multiple
reproduction.
All
transitions
among
these
lifeless
units
may
be
recognized,
from
those
closely
resembling
a
cell
to
enucleated
structures.
As
Hart—
mann
correctly
noted,
we
observe
here
the
termination
of
one
indi-
vidual
development
as
the
result
of
propagation
and
the
initiation
of
a
new
development,
so
that
we
may
in
truth
speak
of
the
death
of
an
individual."
The
question
has
also
been
raised
as
to
whether
the
cell,
endowed
with
perpetual
life,
does
not
change
in
some
way
during
its
life
and
then
become
rejuvenated
by
propagation.
In
attempting
to
UNICELLULAR
ORGANISMS
15
suppress
reproduction,
Rubner"
investigated
this
question
so
far
as
it
concerned
yeast
cells
and
Hartmann
21
studied
it
in
Gonium
pectorale.
Rubner
attempted
to
hinder
reproductive
growth
of
the
yeast
by
controlling
nutritional
conditions
without,
however,
interrupting
other
life
processes.
Under
these
conditions
the
fermenting
power
remained
unchanged
the
fi
rst
four
days
and
then
fell
off,
growth
ceased
and
fi
nally
the
yeasts
died.
Without
growth
and
budding,
the
life
of
the
yeast
is
then
of
limited
and
relatively
short
duration.
Hartmann
experimented
with
Gonium.
In
the
case
of
this
alga,
individuals
of
four
times
normal
size
could
be
cultivated
in
concentrated
solutions
of
nutritive
salts.
They
lived
for
several
weeks
in
contrast
with
normal
ones
which
reproduced
within
one
or
two
days.
This
experiment
fi
nally
resulted
in
the
death
of
those
cultures
in
which
propagation
was
prevented.
All
this
indicates
strongly
that
unicellular
organisms
undergo
altera-
tions
during
their
lives
as
individuals
and
that
by
vegetative
repro-
duction
there
ensues
a
rejuvenation
of
the
cell
plasm.
Hartmann
has
succeeded
in
showing
by
an
interesting
and
very
significant
experiment
that
the
rejuvenating
influence
of
propaga-
tion
can
be
secured
also
by
periodically
repeated
amputation
with
,
resulting
regeneration.
When
the
forward
end
of
the
multicellular
planarian,
Stenostomum
leucops,
was
amputated
52
consecutive
times,
it
could
be
kept
alive
for
13
months,
a
period
during
which
41
divisions
occurred
among
sister
animals.
Similar
results
have
been
secured
with
the
infusorian,
Stentor
coerzdeus,
and
with
two
species
of
amoeba,
A.
Protects
and
A.
potypoda.
.
Hartmann
22
was
able
to
bring
one
individual
of
A.
polypoda
through
32
amputations
and
subsequent
regenerations
during
a
period
of
42
days
in
which
time
another
individual
of
the
same
lineage
divided
15
times.
Under
certain
culture
conditions,
Amoeba
proteins
divides
every
second
day
and
in
the
case
of
this
species
the
afore
-mentioned
author
succeeded
in
prolonging
the
life
of
one
individual
as
long
as
50
days
by
mewls
of
52
amputations.
Hartmann
is
of
the
opinion
that
by
continuing
such
procedure
the
life
of
these
organisms
can
be
prolonged
indefi-
nitely.
The
rejuvenation
which
accompanies
normal
reproduction
can
thus
be
brought
about
by
reduction
of
the
body
through
am-
putation.
Hartmann
believes
that
such
amputation
prolongs
life
by
the
facilitated
exit
it
provides
for
secretion
of
materials
from
the
ampu-
16
THE
LONGEVITY
OF
PEANTS
tated
body.
'Whether
this
is
actually
thd
case
still
a
question
because,
in
my
opinion,
wound
hormones
\
formed
at
the
wounded
surface
might
have
a
rejuvenating
influence
just
as
they
do
among
higher
plants.
Hartmann's
amputation
experiments
have
demonstrated
the
po-
tential
perpetual
life
of
protozoan
cells
and
have
shown
at
the
same
time
that
the
cell
itself
changes
and
that
the
symptoms
of
senes-
cence
are
alleviated
by
vegetative
reproduction.
Vegetative
repro-
duction,
then,
really
brings
along
with
it
a
rejuvenation
and
in
these
investigations
amputation
replaced
it
and
produced
the
same
effect.*
Diatoms
—So far
as
I
know,
botanists
have
not
been
concerned
hitherto
with
Weismann's
idea
of
perpetual
life
as
it
concerns
diatoms
and
certain
other
unicellular
plants.
In
their
case
the
entire
subject
needs
further
elucidation
and
the
following
discus-
sion
will
be
devoted,
therefore,
to
these
forms.
On
the
basis
of
intensive
studies
by
Pfitzer
23
and'
others,
we
know
that
the
special
cell
wall
of
the
diatomaceous
cell
consists
of
two
halves
which
fi
t
one
within
the
other
as
do
the
two
halves
of
a
pill
-box.
Both
halves
are
silicified
to
such
a
high
degree
that
when
once
fully
formed
they
are
incapable
of
further
growth
and
preserve
all
their
structural
features
even
after
being
heated.
When
a
diatom
divides,
the
two
shells
or
valves
are
pushed
apart
by
the
increasing
mass
of
protoplasm
and
each
daughter
-cell
re-
ceives
from
the
mother
-cell
one
old
half
-shell
and
the
other
half
-
shell
must
be
formed
by
the
daughter,cell.
As
a
little
reflection
will
reveal,
the
newly
formed
daughter
-cells
must
accommodate
themselves
to
the
fact
that
the
old
fully
devel-
oped
halves
are
incapable
of
further
growth
because
of
their
great
silicification.
One
of
the
daughter
-cells,
accordingly,
is
as
large
as
the
mother
-cell,
the
other
smaller.
Since
the
newly
formed
shell
of
the
latter
fi
ts
within
the
older
shell,
the
cell
itself
is
shorter
than
the
mother
-cell
around
the
double
thickness
of
the
membrane
and,
according
to
the
binomial
theorem
and
on
the
presumption
that
all
*
Bacteria,
too,
can
alter
their
characteristics
during
the
course
of
their
individual
lives.
As
an
example,
young
cells
are
often
more
sensitive
to
high
temperatures
than
old
ones.
It
has
been
shown
in
investigations
upon
the
heat
resistance
of
high
temperature
-preferring
and
high
temperature
-
resistant
bacteria,
isolated
from
milk,
that
young
bacteria
die
at
relatively
lower
temperatures
than
do
the
old
ones.
This
was
demonstrated
for
Aiicrobacterium
lacticum,
Sarcina
lutes
and
Streptococcus
thermophilus.22a
UNICELLULAR
ORGANISMS
17
cells
divide
equally,
it
can
be
expected
that
within
a
relatively
brief
period
there
will
arise
very
short
cells.
This
continuous
dwarfing
process
naturally
can
not
continue
indefinitely.
Sooner
or
later
there
must
be
a
re-establishment
of
the
original
size
and
this
is
consummated
by
conjugation
or
by
for-
mation
of
auxospores.
According
to
the
species,
it
may
be
accom-
plished
in
a
variety
of
ways
but
only
the
following
cases
will
be
cited.
Two
individuals
lie
side
by
side,
their
protoplasts
fuse
to-
gether
after
separation
of
the
two
valve
-halves
and
eventually
form
the
auxospore
which
then
enlarges
considerably
until
it
acquires
the
original
size
of
the
diatom.
This
is
the
course
of
conjugation
in
Surirella.
As
may
be
noted
in
fi
gure
1,
two
cells
approach
one
another
until
their
narrow
ends
touch.
The
half
-valves
then
separate
and
the
two
proto-
plasts
fuse
into
a
rapidly
en-
larging
auxospore.
In
Rhopa-
a
0
lodia
and
numerous
other
o
a
named
diatoms,
copulation
is
o
a
accomplished
in
a
different
o
o
§
0
manner.
Two
cells
lie
to-
i
i
a
0
gether,
the
valves
separate
o
s
through
a
gelatinous
forma-
0
0
a
tion,
each
protoplast
divides
cs,
into
two
daughter
-cells,
and
0
the
four
cells
thus
formed
fuse
2
in
pairs,
forming
two
auxo-
spores.
The
latter
then
in
-
0
0
crease
in
bulk
up
to
the
maxi-
a
0
mum
size
characteristic
of
their
0
a
a
species.
By_these
auxospores
Q
CI
the
previously
described
pro-
0
a
gressive
reduction
in
size
is
a
o
brought
to
a
definite
though
)
0
Q
variable
limit
and
the
original
size
of
the
diatom
is
restored.
FIG.
1.
Surirella
Saxonica.
Auxo-
In
addition
to
this
sexual
spore
formation.
1:
Two
cells
have
formation
of
auxospores,
an
approached
one
another
with
their
narrower
sides
meeting,
for
the
pur-
asexual
type
is
found
in
vari-
pose
of
fusing;
2:
the
resulting
auxo-
ous
diatoms.
These
asexual
spore.
From
Karsten.
0
18
THE
LONGEVITY
OF
PLANTS
auxospores
are
formed
by
division
of
a
cell
into
two
'daughter
-cells
which
then
enlarge
directly
into
auxospOres,
as,
in
Synedra
and
Rhabdonenta;
or,
as
in
Melosira,
the
cells
may
become
an
auxo-
spore
by
merely
resuming
the
original
size
after
shedding
its
valves.
In
either
case,
whether
auxospore
formation
be
sexual
or
asexual,
the
two
silicified
half
-valves
of
the
mother
-cell
are
dis-
carded.
Can
these
valves
then
be
regarded
as
lifeless
remains
and
the
diatom
looked
upon
as
possessing
only
limited
tenure
of
life?
If
we
regard
the
silicified
envelope
of
the
living
diatom
as
actually
dead
matter,
serving
merely
as
a
shell
around
the
living
mass,
then
it
does
not
die
but
may
be
discarded
during
auxospore
formation
as
an
already
dead
structure;
no
part
of
the
living
protoplasm
can
then
be
said
to
die.
All
this
leads
to
the
following
conclusions
;
.
1)
Because
the
cells
of
successive
generations
must
become
smaller
and
smaller,
it
is
impossible
for
division
of
diatoms
to
continue
indefinitely:
This
is
in
contrast
with
the
situation
among
bacteria,
many
algae
and
infusoria.
2)
The
original
size.
of
the
diatom
is
restored
by
for-
mation
of
the
auxospores.
Whether
the
diatom
reproduces
,
by
cell
division
or
by
auxospores,
the
protoplast
lives
on,
possessing
perpetual
life.
Other
Unicellular
Algae
—There
are
certain
green
unicellular
forms
which
discard
their
membrane
when
they
reproduce
by
con-
version
of
their
protoplasm
into
zoospores
or
aplanospores
;
some-
times
even
their
fl
agellae
and
other
parts
are
lost.
If
the
membranes
are
to
be
regarded
as
structures
that
once
were
alive,
we
can
not
look
upon
these
forms
as
possessing
perpetual
'l
ife.
in
Weismann's
sense
of
the
term.
Botrydium
grawdatum
is
a
small
alga
living
upon
damp
soil
and
consisting
of
a
green
vesicular
aerial
portion
and
a
colorless
root-
like
subterranean
part.
Its
mode
of
reproduction
is
asexual
and
consists
of
internal
formation
of
a
great
number
of
zoospores
which
escape
and
develop
into
new
plants.
The
old
mother
-cell
remains,
however,
as
a
lifeless
membrane
with
various
contents.
Among
the
Volvocales
I
want
to
refer
only
to
Haematococcus
pluvialis
and
Chlamydomonas
nivalis,
and
among
the
Protococcales
to
Chloroeoccum
humicola
and
to
Chlorella
vulgaris.
They
may
well
be
considered
here
as
examples
of
these
two
groups.
UNICELLULAR
ORGANISMS
19
Haematococcus
pluvialis,
an
alga
occurring
frequently
in
rain
puddles,
produces
several
swarm
-cells
just
as
does
Chlamydomonas
nivalis
which
causes
'red
snow'.
These
swarm
-cells
are
liberated
by
a
bursting
of
the
membrane
and
then
develop
into
cells
resembling
the
mother
-cell.
.
This
form
can
reproduce
also
sexually
by
the
for-
mation
of
many
biciliate
similar
gametes
which
fuse
after
being
discharged.
Ch/orococcunt
produces
a
number
of
zoospores
by
internal
divisions,
and
Chlorella,
that
widely
distributed
alga
which
is
so
frequently
encountered
in
symbiotic
relationship
with
the
protoplasm
of
infusoria,
planarians,
Hydra
and
Spongilla,
breaks
up
into,
two,
four
or
eight
aplanospores
which
then
surround
them-
selves
with
walls.
In
all
these
cases
the
wall
of
the
mother
-cell
remains
behind
with
various
other
residua
after
escape
of
the
spores.
Here,
then,
we
can
not
say
that
the
entire
contents
of
the
mother
-cell
'are
trans-
formed
into
daughter
-cells.
Among
higher
plants,
too,
partial
death
is
not
unusual.
When
in
autumn
of
every
year
the
leaves
fall
from
the
trees
and
then
perish;
when
the
tree
discards
its
bark
and
thereby
sheds
dead
tis-
sue
;
when
tissues
die
in
the
forming
heartwood
of
a
living
tree
and
become
laden
with
decomposition
products
;
when
foliar
pubescence
is
shed
naturally
or
when
the
hairs
become
fi
lled
with
air;
or
when
fl
oral
organs
are
discarded
;
in
all
these
cases,
death
of
a
part
of
the
individual
is
involved.
Yeasts
—The
yeast
is
a
unicellular
fungus.
Its
multiplication
is
accomplished
usually
by
budding
which
involves
the
formation
of
a
bulge
at
any
point
in
the
wall
that
gradually
enlarges,
separates
from
the
mother
-cell
and
fi
nally
becomes
independent
by
complete
abstriction.
The
entire
process
is
known
as
budding
and
the
daughter
-cells
as
well
as
the
mother
-cell
are
capable
of
repeating
the
procedure.
This
process
is
somewhat
different,
however,
from
that
which
prevails
in
the
division
of
bacteria
or
of
a
paramaeciufn.
In
the
budding
of
yeast
the
mother
-cell
does
not
divide
into
two
daughter
-
cells
but
abstricts
a
new
daughter
-cell
so
that
the
budding
process
results
in
the
presffvation
of
the original
old
cell
and
the
formation
of
a
new
one.
Since
the
nucleus
divides
in
this
process,
the
two
resulting
cells
probably
acquire
equivalent
nuclei
and,
in
many
cases,
equal
amounts
of
protoplasm.
The
walls,
however,
certainly
20
THE
LONGEVITY
OF
PLANTS
differ
with
respect
to
age,
for
the
abstricting
cell
retains
the
old
membrane
and
the
abstricted
cell
acquir4
a
new
wall.
In
other
words,
in
the
budding
method
of
reproduction
among
yeasts
the
mother
-cell
does
not
resolve
into
two
equivalent
daughter
-cells.
In
this
type
of
division
we
can
not,
however,
speak
of
a
lifeless
residue,
for
the
mother
-cell
can
repeatedly
produce
more
cells
by
abstriction.
Whether
the
mother
-cell
can
continue
this
process
indefinitely
always
provided,
of
course,
with
fresh
nutrient
solution
—or
can
do
so
for
only
a
certain
length
of
time,
has
not
been
experimentally
examined.
The
question
as
to
whether
yeasts
possess,
perpetual
life
has
not
been
answered,
consequently.
It
is
well
known
that
under
special
conditions
involving
free
access
of
oxygen,
favorable
temperature,
and
deficiency
of
food,
many
yeasts
form
asci,
similar
in
external
appearance
to
the
normal
cells
but
which
form
a
few
ascospores.
The
latter
are
eventually
liberated,
forsaking
the
old
cell
together
with
its
wall
and
other
remains
which
then
perish.
It'is
not
very
likely,
however,
in
view
of
the
foregoing,
that
ascus
formation
is
essential
in
the
develop-
ment
of
yeasts,
for
many
species
never.
form
ascospores
at
all
and
those
that
do
may
lose
the
ability
without
suffering
thereby.
We
can
hardly
be
misled,
therefore,
by
the
postulation
that
ascospores
are
merely
a
type
of
resting
spore,
enabling
the
yeast
to
remain
dor-
mant
as
long
as
possible
and
in
this
condition
to
tide
over
unfavor-
able
conditions.
Summary—Weismann's
idea
that
unicellular
organisms
can
continue
living
indefinitely
holds
true
for
most
unicellular
plants.
It
is
certainly
true
of
bacteria
and
blue-green
algae
which
reproduce
only
asexually
by
division
and
without
limit
for
countless
genera-
tions.
Diatoms,
however,
can
not
multiply
indefinitely
by
division
be-
cause,
in
view
of
their
construction,
they
always
become
smaller
and
smaller
and
must,
from
time
to
time,
produce
auxospores
in
order
to
restore
the
original
size
of
the
species.
Though
they
dis-
card
their
old
siliceous
armor
in
this
process,
we
can
not
speak
of
death
in
their
case
because
these
shells
in
themselves
are
dead
material
;
nothing
is
lost
from
the
living
protoplasm
by
either
di-
vision
or
auxospore
formation
and
the
diatoms,
therefore,
may
also
be
regarded
as
everlasting.
The
situation
is
different,
however,
among
those
unicellular
algae
UNICELLULAR
ORGANISMS
21
during
whose
reproduction
not
only
the
wall
of
the
mother
-cell,
but
other
cell
constituents
as
well,
die
and
are
discarded.
In
these
cases
we
already
perceive
a
partial
death
and,
recognizing
that
some
portions
of
the
organism
die,
we
can
no
longer
speak
of
an
unlim-
ited
hold
on
life.
Our
investigations
also
show
that
among
plants
death
is
not
a
general
characteristic
of
living
matter
(bacteria,
Cyanophyceae,
etc.)
but
that
it
just
begins
to
develop
in
certain
unicellular
forms
in
that
isolated
portions
of
the
cell
die
during
reproduction
and
remain
as
dead
residue.
LENGTH
OF
GENERATION,
DAILY
PROGENY,
INDIVIDUAL
LONGEVITY
Whenever
mention
has
been
made
in
the
foregoing
of
perpetual
life
among
single
cells
it
has
not
been
implied
that
they
are
in-
capable
of
dying.
Every
unicellular
organism
can
experience
con-
ditions
under
which
it
eventually
dies.
Many
bacteria,
algae,
in-
fusoria
and
fl
agellates
can
not
endure
drying
out.
Many
succumb
to
cold
and
all
succumb
to
heat
between
100°
and
150°
C.
and
to
various
poisons
and
other
unfavorable
factors.
In
these
cases
the
individual
usually
remains
as
a
dead
body;
therefore,
we
may
speak
of
death
among
unicellular
forms.
Only
when
such
injuries
are
avoided
and
multiplication
proceeds
unabated,
is
the
living
sub-
stance
of
the
mother
-cell
continually
transferred
by
division
into
daughter
-cells.
This
multiplication
proceeds
at
different
rates
among
different
forms,
exceedingly
rapid
as
in
many
bacteria
and
yeasts,
moderately
rapid,
or
slowly
as
among
fl
agellates,
diatoms
and
infusoria.
Before
discussing
this
further
it
will
be
well
to
refer
to
some
important
conceptions
which
occasionally
are
not
clearly
distin-
guished
from
one
another.
I
have
in
mind
length
of
generation,
daily
progeny,
and
individual
longevity._
Length
of
generation
is
the
time
within
which
an
individual
di-
vides,
i.e.,
the
lapse
of
time
from
the
initiation
to
the
conclusion
of
a
division.
Daily
progeny
is
the
number
of
descendants
arising
from
any
one
cell
during
a
day.
Individual
longevity
of
a
cell
is
the
lapse
of
time
from
one
cell
division
to
the
next.
In
rapid
cell
division
one
division
may
follow
directly
upon
the
completion
of
22
THE
LONGEVITY
OF
PLANTS
the
preceding
and
then
the
individual
longevity
becomes
reduced
to
nil
or
to
a
minimum.
Concerning
the
correlation
between
longevity
and
external
in-
jurious
factors
and
decrease
of
resistance,
the
reader
is
referred
to
Putter.
24
Bacteria
—According
to
prevailing
views,
a
bacillus
of
the
com-
mon
saprophytic
type
divides
under
.favorable
conditions
more
or
less
every
20
or
30
minutes.
25
'r
,
Such
a
rate
must
be
regarded
as
very
rapid
because
we
know
of
no
other
form
of
life,
at
least
in
the
light
of
recorded
observations,
which
multiplies
so
rapidly
as
do
bacteria.
Their
daily
progeny
is
extraordinarily
large
and
their
individual
lives,
accordingly,
are
very
short.
This
is
not
always
true,
however,
for
many
bacteria,
even
under
favorable
conditions,
grow
very
slowly.
The
daily
progeny
of
tubercle
bacilli
must
be
much
less,
as
is
indicated
by
the
slow
development
of
colonies.
Food,
temperature,
light,
assimilation
products
and
other
factors
certainly
exert
great
influence
upon
the
rate
of
numerical
increase
so
that
the
daily
progeny
even
of
the
same
species
is
not
always
constant
but
very
variable.
If
unfavorable
conditions
prevail,
bacteria
may
experience
star-
vation
or
begin
to
suffer
from
their
own
excretion
products.
In
such
cases
they
produce
resting
spores
which,
as
the
name
indi-
cates,
can
long
exist
as
individuals
until
under
favorable
circum-
stances
they
again
begin
to
divide.
I
shall
refer
to
this
in
the
dis-
cussion
of
apparent
death.
Yeasts
—The
rate
of
multiplication
among
yeasts
appears
mark-
edly
lower
than
among
most
bacteria
but
as
contrasted
with
other
unicellular
forms
it
is
of
considerable
magnitude.
The
duration
of
a
generation,
i.e.,
the
period
of
time
requisite
for
full
development
of
a
daughter
-cell
which
originates
by
bud-
ding
of
the
mother
-cell,
can
be
determined
by
direct
observation
in
a
hanging
drop
or
by
calculation
according
to
Basenau's
26
formula.
This
states
that
t
log
2
x=
log
b
log
a
where
a
represents
the
original
number
of
cells,
b
the
number
of
cells
secured
and
t
the
duration
of
the
investigation.
The
formula
is
valid,
however,
only
under
the
assumption
that
the
length
of
UNICELLULAR
ORGANISMS
23
generation
during
the
entire
time
t
is
the
same
for
every
cell
of
the
culture
and
that
each
new
daughter
-cell
immediately
begins
to
bud.
Especially
is
the
latter
of
these
conditions
frequently
lacking,
whereupon
the
length
of
generation,
calculated
according
to
the
formula,
is
too
great."
Pedersen
28
"
determined
the
length
of
generation
in
the
beer
yeast
under
different
temperatures
and
secured
the
following
values
during
the
fi
rst
24
hours
of
development
:
LENGTH
OF
GENERATION
OF
BEER
YEAST
Temperature
Duration
of
generation
C.
20
hours
13.5°
C.
10.5
"
23°
C.
6.5
"
28°
C.
5.8
"
34°
C.
9
"
38°
C.
No
budding.
By
using
gelatine
and
the
same
formula,
Hoyer"
secured
the
following
:
LENGTII
OF
GENERATION
OF
BEER
YEAST
Length
of
generation
13°
C.
25°
C.
Saccharomyces
Pastorianus
I
Hansen
6
Hr.
6
Alin.
Saccharomyces
Pastorianu
s
II
8
"
45
"
5
Hr.
12
Alin.
Saccharomyces
Pastorianus
III
8
"
39
CC
6
"
8
"
Saccharomyces
_ellipsoidens
I
9
"
4
IC
6
"
12
Saccharomyces
ellipsoideus
II
8
"
49
CI
6
"
9
Saccharomyces
anomalus
5
"
12
1
-
4
Saccharomyces
Ludwigii
8
"
10
6t
Saccharomyces
membranoefaciens
7
•CC
5
CC
13
Yeast
Saaz
7
"
48
CC
4
23
Yeast
Frohberg
Yeast
apiculatus
7
4
"
"
21
45
CC
it
CI
4
18
The
above
data
indicate
that
under
favorable
conditions
the
lengths
of
generation
of
different
species
of
yeast
vary
from
four
24
THE
LONGEVITY
OF
PLANTS
to
nine
hours
and
are
influenced
to
a
great
extent
by
temperature.
Further
experimentation
will
certainly
show
I
l
iere
also
three
cardinal
temperatures
with
respect
to
length
of
generation
and
the
latter
will
be
shortest
at
a
particular
intermediate
point,
the
optimum
temperature.
If
the
propagation
takes
place
within
a
limited
space,
deficiencies
of
food,
and
poisonous
secretion
products
will
soon
exert
an
influ-
ence
to
such
a
degree
that
the
rate
of
multiplication
will
progres-
sively
decrease
and
fi
nally
become
nil.
It
may
be
mentioned,
inci-
dentally,
that
other
factors
also
can
influence
the
length
of
genera-
tion,
e.g.,
the
composition
and
concentration
of
the
substratum,
light
and
the
age
of
the
budding
cell.
How
long
does
the
yeast
cell
remain
viable
and
capable
of
further
development
when
external
conditions
render
budding
and
spore
formation
impossible?
We
must
here
distinguish
between
yeast
cells
under
dry
and
those
under
moist
conditions.
Many
kinds
are
very
susceptible
to
desiccation
and
the
longevity
of
the
individual
is
very
short.
Brefeld
has
shown
that
dried
cultures
of
yeast
lose
their
ability
to
multiply
after
14
days.
According
to
Hensen,
yeast
kept
between
sterile
blotting
paper
remains
viable
at
times
for
5
to
20
months.
Four
years
has
been
recorded
as
the
longest
period
of
viability
for
dried
vegetative
cells
of
a
wine
yeast
and
,five
years
for
its
spores.
3
°
Yeast
spores
generally
retain
viability
longer
than
common
bud
cells
and
in
this
respect
resemble
resting
spores
of
bacteria.
Under
moist
conditions
the
longevity
of
yeast
cells
is
consider-
ably
shorter
and
is
dependent
upon
water
content,
the
particular
strain
and
the
individual
cell
itself.
Lafar
says
"Few
resistant
cells
long
outlive
the
main
mass.
The
inherent
nature
of
-the
new
breed
likewise
determines
whether
its
longevity
will
be
longer
or
shorter.
The
lower
the
temperature
at
which
the
cells
are
held,
the
longer
do
they
remain
viable.
Henneberg
has
shown
that
12°
C.
is
considerably
more
unfavorable
than
C.
At
C.
and
after
120
days
a
fi
fth
of
the
cells
still
remained
viable
in
the
case
of
Froh-
berg
yeast.
At
22°
C.
this
strain
lived
about
three
weeks;
at
30°
C.
it
lived
less
than
one
week,
and
strains
II
and
XII,
as
in
the
case
of
Frohberg
yeast,
lived
about
three
weeks
at
22°
C.,
though
to
a
slight
extent
as
'reserve
cells.'
In
cultures
-
of
dense
masses
the
cells
generally
die
earlier
than
in
thinner
masses,
probably
as
the
UNICELLULAR
ORGANISMS
25
result
of
an
accumulation
of
metabolic
products.
For
the
same
reason
cells
within
the
mass
die
earlier
while
those
on
the
surface
live
longer.
The
longevity
of
yeast
is
relatively
short,
therefore,
when
the
cells
are
saturated
with
water."
31
Such
observations
may
be
of
practical
value
because,
as
is
well
known,
yeasts
are
grown
commercially
and
the
most
suitable
means
of
preserving
them
in
living
cultures
is
of
importance
for
both
the
brewery
and
the
home.
Peridiniidae—We
are
indebted
to
Hensen
32
for
observations
concerning
the
rate
of
multiplication
among
the
Peridiniidae.
In
order
to
determine
the
daily
increase
by
division,
he
employed
the
same
formula
which
is
used
in
the
calculation
of
compound
interest,
applying
the
interest
rate
not
for
the
year,
however,
but
f
or
the
day.
If
A
represents
the
initial
capital,
w
the
interest
rate,
n
the
number
of
days
during
which
the
capital
bears
interest,
and
C
the
total
of
both
capital
and
compound
interest,
then
the
formula
reads
or,
logarithmically
stated:
log
C
log
A
log.
If
we
decrease
the..interest
rate,
or
rate
of
increase,
by
one,
we
obtain
the
interest.
On
the
basis
of
numerous
calculations,
Hensen
found
the
rate
of
increase
among
Peridiniidae
to
average
1.2.
This
means
that
each
cell
divides
on
the
average
after
fi
ve
days.
If
the
Peridiniidae
divide
once
within
fi
ve
days,
the
daily
progeny
of
the
mass
regu-
larly
amounts
to
one
-fifth
of
the
entire
mass.
Diatoms
—Using
Apstein's
plankton
catches,
Hensen
has
calcu-
lated
also
the
rate
of
multiplication
among
diatoms
and
has
found
it
to
be
similar
to
that
of
the
Peridiniidae,
namely,
1.2
or
1.25,
involving,
therefore,
a
division
every
four
days.
Benecke
33
attempted
to
determine
the
rate
of
multiplication
among
colorless
diatoms
in
hanging
drops.
For
this
purpose,
Nitzschia
putrida
is
well
suited.
A
piece
of
yeast
scum,
beset
with
colorless
specimens
of
Nitzschia
or
a
particle
of
slime,
was
placed
upon
a
cover
glass
in a
hanging
drop
and
observed
directly
under
the
microscope.
The
author
himself
says
he
was
not
successful
in
securing
consistent
results,
obviously
because
of
other
conflicting
26
TIIE
LONGEVITY
OF
PLANTS
organisms
which
developed
at
the
same
time
in
the
drop.
He
con-
fi
nes
himself,
therefore,
to
the
statement
that
"the
most
rapid
mul-
tiplication
was
exhibited
by
two
specimens
of
Nitzschia
putrida
in
one
culture
which
within
a
week's
tithe
divided
twice.
'On
April
7
two
.
specimens
were
to
be
seen
in
the
drop
and
eight
on
the
14
(at
room
temperature
and
in
darkness)."
Also
Karsten
34
made
extensive
observations
on
the
rate
of
multi-
plication.
They
are
all
the
more
significant
since
they
were
con-
duCted
with
various
species
and
under
a
variety
of
culture
condi-
tions.
They
indicate,
accordingly,
how
greatly
the
rate
is
influenced
by
the
composition
of
the
nutrient
solution
and
by
other
external
conditions
such
as
light
and
darkness.
The
cultures
were
grown
partly
in
glass
boxes,
partly
upon
concave
slides
and
partly
in
hanging
drops.
For
further
details
the
original
account
should
be
consulted,
but
the
results
of
Karsten's
work
as
indicated
in
the
table
on
page
27
may
be
emphasized.
This
table
indicates
that
the
daily
progeny
of
Peridiniidae,
as
de-
termined
by
Hensen,
is
often
surpassed
and
that
in
the
case
of
the
colorless
and
exclusively
saprophytic
Nitzschia
putrida
a
value
as
high
as
3.16
may
be
obtained
which
means
that
these
diatoms
may
produce
at
their
best
as
many
as
2.16
individuals
per
day.
Karsten
remarks
-in
this
connection,
however,
that,
since
for
his
investiga-
tions
only
rapidly
increasing
forms
were
studied
and
all
slowly
growing
ones
were
disregarded,
a
daily
progeny
of
1.2
may
be
re-
garded
in
general
as
a
better
average
of
multiplication
among
unicellular
plants.
This
conclusion
appears
to
me
too
broad
in
its
generalization,
for
bacteria
also
are
unicellular
organisms
and
many
times
exhibit
a
much
greater
daily
progeny
than
1.2.
Even
among
diatoms
this
rate
of
increase
may
be
too
low
in
many
and
perhaps
in
most
cases.
Richter"
has
determined
the
daily
progeny
of
Nitzschia
putrida
in
carefully
conducted
pure
cultures
and
found
a
much
greater
value.
According
to
thiS
author,
it
divides
once
every
fi
ve
hours
during
the
second
day.
This
striking
difference
in
the
fi
ndings
of
Benecke
and
Karsten
on
the
one
hand
and
of
Richter
on
the
other
is
to
be
accounted-
for,
according
to
Richter,
by
the
fact
that
Benecke
and
Karsten
worked
with
ordinary
cultures
while
he
employed
pure
cultures.
Richter
ventures
to
say
that
continued
increase
of
bac-
teria
in•
ordinary
cultures
is
hindered
by.
their
own
secretions.
UNICELLULAR
ORGANISMS
DAILY
PROGENY
OF
DIATOMS
27
Daily
progeny
Light
Darkness
Navicula
perpusilla
1.26
1.19
Nitzschia
Palea
1.18
1.09
1.28
1.17
1.16
1.36
1.17
1.36
1.21
1.11
Nitzschia
Closteriunt
1.65
1.65
1.26
1.60
1.84
1.56
1.58
1.68
.
.
.
1.41
Nitzschia
dubia
2.62
0
2.00
0
1.86
0
1.97
0
1.85
0
Nitzschia
putrida
2.08
2.2
1.9
2.64
1.87
1.58
3.16
2.74
1.87
Desmids-W6
are
indebted
to
Andreesen
36
for
information
con-
cerning
the
length
of
generation
among
these
algae.
The
rapidity
of
cell
division
varies
according
to
the
nutrient
solution
and
the
in-
dividuality
of
the
cellls.
When
provided
with
leficiti
,
albumin,
dung
extract
or
pea
decoction,ix.,
when
under
favorable
nutritional
conditions,
the
length
of
generation
of
Closteriunt
monilifonne
is
about
two
days.
From
the
initial
stage
of
abstriction
to
the
forma-
tion
of
a
fully
developed
daughter
-cell
is
a
period
of
about
one
day.
In
the
case
of
Cosmarittin
Botrytis
the
length
of
generation
varies,
according
to
the
nature
of
the
solution,
from
2
to
3.5
days.
28
THE
LONGEVITY
OF
PLANTS
Hyalotheca
dissiliens
required
four
to
fi
ve
days
for
a
doubling
of
the
number
of
cells
in
a
fi
lament.
The
length
of
generation
of
a
single
cell
of
this
alga
could
not
be
determined
with
certainty
but,
according
to
Andreesen,
it
amounts
to
48
hours
in
this
genus
also.
Flagellates
—Certain
flagellates,
such
as
Euglena,
gracilis,
like-,
wise show
a
relatively
high
rate
of
multiplication,
3
I
particularly
when
provided
with
mixotrophic
nutrition.
This
accounts
for
the
fre-
quent
exceedingly
abundant
and
rapid
appearance
of
Euglena
and
other
micro-organisms
in
manure
puddles.
In
water
barrels
to
which
cow
dung
had
been
added
to
secure
a
good
fertilizing
water,
I
have
often
observed
Euglena
viridis
appear
in
such
great
abun-
dance
that
the
upper
layers
were
composed
of
a
deep
green
creamy
mass,
almost
exclusively
of
Euglena.
Summary
—Everything
taken
into
consideration,
our
knowledge
of
the
length
of
generation,
of
the
'daily
progeny
and
of
the
indi-
vidual
longevity
of
unicellular
organisms
is
still
exceedingly
incom-
plete.
..
In
contrast
with
the
great
number
of
existing
species
of
unicellular
forms,
the
number
of
pertinent
observations
appears
markedly
insignificant.
Furthermore,
our
information
concerning
length
of
generation
or
daily
progeny
gives
nothing
definite
regard-
ing
individual
longevity.
To
shed
light
upon
this
point,
further
extensive
observations
on
the
various
groups
of
the
simplest
organ-
isms
must
be
made.
For
convenience,
our
knowledge
concerning
length
of
generation
and
daily
progeny
among
fungi,
algae
and
certain
other
organisms
may
be
summarized
according
to
the
table
on
page
29.
From
this
table
it
appears
at
fi
rst
sight
that
the
length
of
gen-
eration
among
unicellular
organisms
increases
with
increase
in
size.
Bacteria,
as
the
smallest,
exhibit
a
very
short
division
period
and
the
.
relatively
large
Peridiniidae
and
diatoms
show
a
much
longer
period.
However,
though
the
length
of
generation
may
be
corre-
lated
with
size,
it
does
not
appear
dependent
upon
size
alone,
for
the
comparatively
large
amoebae
and
cells
of
staminal
,hairs
in
Tradescantia
(length
of
generation:
80
minutes),
though
they
are
quite
large,
nevertheless
possess
a
short
division
period.
Other
factors
also
must
then
control
the
length
of
generation.
A
satis-
factory
answer
as
to
what
these
factors
may
be
will
be
secured
prob-
ably
only
when
abundant
material
of
the
most
varied
unicellular
forms
becomes
available
for
study.
LENGTH
OF
GENERATION
AND
DAILY
PROGENY
IN
UNICELLULAR
ORGANISMS
Class
Species
Length
of
generation
Daily
progeny
Time
after
which
a
division
took
place
Author
Bacteria
20-30
Min.
Vibrio
cholerae"
Bacillus
coli
communis"
20
Min,
25
Min.
A.
Fischer
Yeasts
R.
Petersen,
et
al.
Peridiniidae
4-20
Hrs.
1.2
5
days
V.
Hensen
Gymnodinium"
E.
Kiister
Diatoms
24
Hrs.
1.25
4
days
V.
Hensen
Nitzschia
if
Palea
1.26
3.8
days
,
in
light
5.2
days
in
dark
Closteriuni
1.19
1.7
days
G.
Karsten
dubia
it
putrida
1.58
2.06
22.8
hrs.
19.4
hrs.
putrida
2.23
5
h
rs.
0.
Richter
Desmids
Closterium
A.
Andreesen
Cosmarium
48
Hrs.
Amoebae
38
10
MM.
A.
Fischer
UNICELLULAR
ORGANISMS
CHAPTER
II
THE
LONGEVITY
OF
MULTICELLULAR
ORGANISMS
The
body
of
a
many
-celled
plant
is
composed,
as
-is
true
of
simi-
lar
animals,
of
two
kinds
of
cells,
body
or
somatic
cells
and
repro-
ductive
cells.
In
many
lower
plants
the
difference
may
not
always
be
great
but
with
progressively
increasing
division
of
labor
it
be-
comes
more
apparent.
The
distinction
may
be
observed
clearly,
however,
among
certain
plants
of
relatively
primitive
organization,
as
in
many
of
the
Volvocales.
The
green
alga
Volvox
forms
hollow
globular
colonies
consist-
ing
of
many
protoplasts
which
are
connected
with
one
another
by
fi
ne
protoplasmic
threads.
The
cells
are
not
alike,
however,
but
are
differentiated
into
body
and
reproductive
cells.
The
latter
constitute
spermatozoids
and
egg
cells.
The
male
sex
cells
arise
by
division
of
colony
cells
into
numerous
daughter
-cells
and
appear
as
minute
biciliate
motile
cells
while
the
eggs
represent
enlarged
green
immotile
colony
cells
surrounded
by
a
mucilaginous
sub-
stance.
Fusion
of
an
egg
cell
with
a
spermatozoid
within
the
globular
colony
gives
rise
to
an
oospore
which
later
forms
a
new
colony.
Volvox
can
reproduce
also
asexually
by
development
of
daughter
colonies
through
division
of
colony
cells.
The
reproductive
cells
are
the
evidence
of
continued
regenera-
tion
while
the
residual
body
cells
represent
the
transitory
stage.
This
is
true
not
only
of
the
simple
Volvox
but
also
of
the
higher
fungi,
mosses,
ferns
and
trees.
I
am
in
complete
agreement
with
Weismann
when
he
looks
upon
death,
in
the
last
analysis,
as
a
means
of
expediency
and
says
that
he
does
not
believe
that
"life
has
only
a
certain
period
of
existence
merely
because
of
its
nature
but
rather
that
an
unlimited
tenure
of
life
would
be
a
wholly
useless
extravagance."'
Nature
follows
her
own
course
and
is
not
deter-
red
by
death
when
the
latter
would
serve
some
purpose.
Before
entering
upon
the
problem
of
death,
particularly
upon
its
causes
and
the
associated
phenomena
of
plant
life,
we
shall
briefly
consider
longevity
among
the
various
groups
of
plants
and
thereby
30
M
ULTICELLULAR
ORGANISMS
31
fi
ll
a
noteworthy
deficiency
in
botanical
literature.
There
has
never
been
such
a
compilation
concerning
the
entire
plant
kingdom.
CRYPTOGAMS
ALGAE
Though
the
algae
have
been
intensively
investigated
from
vari-
ous
viewpoints
and
much
has
been
contributed
concerning
their
life
histories,
we
have
very
little
definite
information
respecting
their
longevity.
Observations
directed
particularly
upon
this
as
pect
are
entirely
lacking
and
I
am
able,
consequently,
to
present
only
meagre
information
upon
the
subject,
derived,
for
the
most
part,
from
Oltmanns.
41
As
is
well
known,
the
Laminariales
include
many
genera
of
extraordinary
size.
The
stalk
of
Laminaria
saccharina
attains
a
length
of
from
1.
to
11
in.
and
that
of
L.
longirostris
may
become
as
much
as
5
in.
in
length;
the
spread
of
the
former
may
be
2-1-
to
3
in.
and
that
of
the
latter
4
m.
long
and
60
cm.
wide.
Many
species
of
Lessonia
are
tree
-like
in
appearance
and
the
stein
of
L.
fuscescens
becomes
3
to
4
in.
long
and
thick
as
a
man's
leg.
Nereocystis
at-
tains
a
total
length
of
100
in.
and
the
stalk
of
Macrocystis
may
be
as
much
as
200
m.
in
length.
In
its
lower
portion
the
stalk,
secured
to
stones
by.
its
holdfast,
is
thick
and
destitute
of
leaves
while
the
upper
portions
are
rope
-like
and
foliose.
This
astonishing
length
of
Macrocystis
pyrifera
is
all
the
more
remarkable
in
view
of
the
fact
that
these
plants
are
of
very
primitive
organization
and
belong
to
the
algae.
The
tallest
trees,
by
comparison,
attain
heights
of
140
to
150
in.
We
may
suppose
in
view
of
the
colossal
size
of
these
algae
that
such
plants
do
not
complete
their
development
within
one
year
but
require
several
years.
I
have
been
unable
to
fi
nd
in
the
literature
any
information
concerning,
the
exact
age
of
such
algae.
Oltmanns
is
in
accord
when
he
remarks
that
we
are
still
uninformed
concerning
the
age
of
large
species
among
the
Lami-
nariales
and
that
the
only
information
which
he
found
was
a
note
by
Foslie
42
stating
that
four
to
fi
ve
yeals
elapsed
before
a
location,
once
denuded
of
its
growth
of
Laminariales,
was
again
colonized
by
specimens
about
one
meter
in
height."
On
the
assumption
that
growth
in
length
,remains
approximately
the
same
during
a
long
period
of
time
and
that
this
growth
amounts
to
one
meter
every
four
years,
a
stalk
of
Macrocystis
pyrif
era,
100
to
200
m.
long,
must
32
THE
LONGEVITY
OF
PLANTS
be
100
to
200
years
old.*
Though
this
estimate
may
be
only
ap-
proximate
it
is,
nevertheless,
certain
that
this
species
of
Macrocystis
can
attain
an
age
which
is
common
only
among
trees.
It
is
natural
that
the
rings
observable
in
cross
-sections
of
stems
in
Laminaria,
often
8
to
12
and
more
in
number, should
be
regarded
as
annual
rings.
However,
though
their
formation
may
be
asso-
ciated
with
changes
in
foliage
or
growth
periods,
there
unfortunately
is
no
good
reason
as
yet
for
regarding
them
with
certainty
as
annual
rings.
We
can
not
employ
them,
therefore,
for
the
determination
of
age.
In
addition
to
those
algae
which
live
for
years,
there
are
numer-
ous
others
which
live
for
two
years
and
fi
nally
an
enormous
number
that
exist
for
only
one
period
of
vegetative
growth
and
which
we
can
regard,
though
not
entirely
correctly,
as
annuals.
Among
them
are
many
species
which
live
for
only
a
few
weeks,
as
is
indi-
cated
by
their
periodic
occurrence
and
sudden
appearance
in
great
numbers
and
their
equally
sudden
'disappearance.
These
may
be
regarded
as
the
shortest
-lived
among
the
algae.
Many
algae
can
withstand
unfavorable
periods
by
various
means,
some
the
summer,
others
the
winter.
Among
them,
zygotes,
oospores
and
other
special
cells
assume
the
role
played
in
this
respect
by
seeds
and
bulbs
among
higher
plants.
FUNGI
If
we
cover
fresh
moist
horse
-dung
with
a
bell
-glass,
a
dei
-
ise
moldy
growth
of
Mucor
Mucedo
0
appears
after
a
few
days.
Sub-
sequent
to
formation
of
sporangia
the
fungus
declines
and
in
its
place
appears
Pilobolus
crystallinus
which
:discharges
its
sporangia
toward
the
glass
wall,
the
source
of
light,
and
then
also
disappears
in
a
few
days.
It
is
followed
by
a
smaller
mushroom,
a
species
of
Coprinus,
which
lasts
for
only
a
few
weeks.
Finally
we
observe
a
fungus
of
macroscopic
size,
often
no
larger
than
a
pinhead,
which
belongs
to
the
ascomycete
Ascobolus.
This
rapid
succession
of
fungal
genera,
suddenly
appearing
and
then
declining,
indicates
that
very
short-lived
fungi
which
live
for
only
a
few
days
or
weeks
are
involved.
Do
we
not
observe
a
similar
situation
in
the
woods
?
As
though
by
a
stroke
of
magic,
a
multitude
of
the
most
varied
*
Though
these
fi
gures
appear
inaccurate,
they
represent
a
correct
transla-
tion
of
the
original
German.
—E.
H.
F.
MULTICELLULAR
ORGANISMS
33
mushrooms
(Agaricaceae,
Hydnaceae,
Clavariaceae)
appears
on
the
fl
oor
of
the
woods
after
abundant
rain
and
warm
weather
and
then
disappears
as
quickly.
They
live
for
only
a.
few
days
or
weeks
and
the
question
arises
as
to
how
long
the
mycelium
existed
in
the
ground
and
supplied
necessary
materials
for
formation
of
fruiting
bodies.
Thousands
of
microscopic
multicellular
fungi,
occupying
the
greatest
variety
of
places
saprophytically
or
parasitically,
rarely,
-
exceed
one
half
to
two
years.
Many
Myxomycetes,
and
Phycomycetes
such
as
species
of
Chytri-
diaceae,
Saprolegniaceae
and
Mucoraceae
are
short-lived
and
usually
live,
except
for
their
spores,
only
a
few
weeks.
There
are
also
the
parasitic
Synchytriaceae,
Cladochytriaceae,
Peronosporaceae,
Usti-
laginaceae
and
Uredineae,
and
among
these,
particularly
the
Perono-
sporaceae
and
the
rusts
and
smuts
possess
mycelia
which
live
for
months
upon
the
host
plants.
We
are
indebted
to
Jahn
44
for
noteworthy
investigations
on
the
longevity
of
plasmodia.
His
studies
were
concerned
entirely
with
the
plasmodium
of
the
slime
-fungus
Badhainia
utricularis
Berk.
This
species
grows
very
energetically
and
may
easily
be
cultivated
upon
fungi
which
in
Nature
supply
it
with
nourishment.
In
the
dry
atmosphere
of
a
room
it
rapidly
forms
sclerotia
and
when
deprived
of
food
it
soon
sporulates.
The
longevity
of
the
fi
rst
cul-
tivated
plasmodium
amounted
to
77
days.
Three
other
samples
of
the
same
strain
lived
77,
71
and
76
days,
respectively.
There
was
an
individual
peculiarity
of
this
material,
however,
for
speci-
mens
secured
from
other
sources
could
be
kept
alive
115,
145
and
150
days.
Jahn
noted
two
years
and
one
month
as
the
maximum
longevity
among
his
plasmodia.
Growth
was
generally
vigorous
.at
fi
rst,
then
gradually
declined
and
fi
nally
ceased.
This
decreasing
growth
was
not,
however,
the
only
indication
of
senescence.
By
employing
plasmodia
of
various
ages
and
allowing
them
to
become
moist
again
after
fi
rst
drying
out,
Jahn
was
able
to
make
the
interesting
observation
that
young
plasmodia
readily
resumed
activity
but
that
aged
material
did
so
with
difficulty
or
not
at
all.
Jahn
remarks
in
this
connection
that
the
true
curve
of
'duration
of
latent.
life
probably
ascends
rapidly
at
fi
rst
and
then
descends
slowly,
suddenly
falling
off
abruptly,
and
after
a
while
continues
to
decline
as
a
straight
line.
Jahn
concluded
34
THE
LONGEVITY
OF
PLANTS
that
the
plasmodium
suffered
equally
from
loss
of
vitality
whether
in
a
dry
or
active
condition.
These
studies
indicate
that
even
in
a
simple'
organism
as
is
rep-
resented
by
a
slime
-mold,
youth,
middle
age
and
old
age
may
be
observed.
In
the
case
of
a
long-lived
plasmodium
of
about
three
and
a
half
years,
the
youthful
stage,
i.e.,
the
period
of
energetic
vitality
and
growth,
lasts
for
about
six
months
and
is
then
followed
by
a
critical
period
of
decreased
vitality
and
increased
perishability.
This
is
the
behavior
of
the
protoplasm
under
cultivation
;
in
Nature
the
vege-
tative
condition
persists
during
the
humid
autumn
probably
no
longer
than
four
to
six
weeks.
Among
the
Ascomycetes
are
short-
,and
long-lived
species
of
Ascobolits,
Morchella
and
Peziza
which
rapidly
disappear
when
they
have
attained
the
fruiting
stage
;,`many
Ascomycetes,
on
the
contrary,
over
-winter,
as
in
the
case
of
Rhytisina
acerina
which
produces
the
familiar
black
spots
on
maple
leaves.
Conidia
develop
during
summer
and
autunin
which
over
-winter
and
not
until
spring
do
the
ascocarps
appear
as
the
fi
nal
stage
on
decaying
leaves
upon
the
ground.
The
greatest
longevity
among
fungi
is
to
be
found
among
woody
and
corky
polypores
which
form
large
bracket
-like
fruiting
bodies
on
trees
and
often
require
many
years
for
their
,complete
develop-
ment.
The
foregoing
account
indicates
how
incomplete
our
knowledge
is
concerning
longevity
of
fungi
and
that
it
is
impossible
at
present
to
present
more
exact
details.
I
have
found
nothing
particularly
concerning
longevity
in
mycological
literature,
not
even
in
de
Bary's
45
well-known
work
on
the
comparative
morphology
and
biology
of
fungi
and
other
plants,
and
this
is
equally
true
for
lichens.
Should
such
investigations
be
undertaken
at
some
future
time,
attention
must
then
be
paid
also
to
the
various
organs
of
fungi,
for,
though
the
pileus
of
the
common
edible
mushroom
and
of
other
species
may
live
for
only
a
few
weeks,
the
mycelium
which
remains
in
the
substratum
may
behave
altogether
differently.
It
may
re-
sume
activity
again
and
again,
dying
off
in
its
older
parts.
Atten-
tion
must
be
paid
to
how
long
individual
cells
of
the
mycelium
remain
alive
and
it
will
probably
be
found
that
the
mycelial
cells
MULTICELLULAR
ORGANISMS
35
can
attain
a
greater
age
in
general
than
those
of
the
fruiting
body
with
the
exception,
of
course,
of
spores.
Twenty-five
years'
experience
with
the
unusual
hyphae
of
my-
celium
X,
as
shown
by
their
developmht
in
light,
have
indicated
to
me
that
this
mycelium
suffers
in
vitality
within
a
year's
time
when
kept
under
air-dry
conditions
anci
that
the
same
is
true
also
of
Xylaria
Hypoxylon.
Many
fungi
can
survive
long
rest
periods
by
means
of
sclerotia
and
other
states
of
the
mycelium.
The
duration
of
this
period,
as
in
the
case
of
seeds,
bulbs
or
root
-stocks,
varies
individually
and
specifically
according
to
conditions.
MOSSES
In
all
the
bryological
literature
to
which
I
have
had
access
so
far,
I
have
found
information
concerning
the
age
of
mosses
in
only
one
study
by
Reichardt."
In
trees
and
shrubs
the
age
of
the
stem
may
be
determined
ana-
tomically,
among
other
means,
by
the
number
of
annual
rings,
and
in
the
case
of
certain
herbaceous
plants,
e.g.,
Convallaria
polygo-
natant,
the
age
of
the
rhizome
can
be
ascertained
morphologically
by
the
number
of
scars
representing
aerial
shoots.
Among
mosses,
however,
there
are
no
indications
of
age
within
the
tiny
stem
and
for
this
reason
Reichardt
attempted
to
establish
the
age
of
moss
stems
morphologically
by
vegetative
relations
and
by
the
regular
succession
of
axes.
He
came
to
the
conclusion
that
we
"can
deter-
mine
the
age
of
moss
stems
in
all
those
cases
where
there
is
a
regu-
lar
succession
of
axes
of
different
rank,
each
of
which
indicates
a
region
of
annual
growth."
Otherwise,
he
says,
the
age
of
a
moss
stem
can
not
be
determined.
Since
Bridel,
two
large
groups
of
mosses
have
been
recognized,
the
acrocarpic
and
the
pleurocarpic.
The
acrocarpic
are
those
whose
main
axis
terminates
in
reproductive
organs.
They
possess
limited
growth,
therefore,
and
when
they
produce.
lateral
branches,
these,
too,
give
rise
to
fruiting
bodies
at
their
ends
and
have,
like-
wise,
determinate
growth.
Production
of
reproductive
organs
occurs
only
once
a
year
and
the
age
of
the
stern
may
be
determined
according
to
the
number
of
successive
annual
shoots.
The
axes
of
pleurocarpic
mosses,
on
the
other
hand,
have
inde-
terminate
growth.
Their
reproductive
organs
do
not
arise
on
the
36
THE
LONGEVITY
OF
PLANTS
ends
of
the
axes
but
laterally.
Because
of
this,
the
age
of
such
mosses
can
not
as
a
rule
be.
determined
with
certainty.
While
referring
to
Reichardt"s
discus-
sion
in
connection
with
those
features
which
reveal
the
age
of
various
mosses,
I
want
to
call
attention
to
his
remarks
con
-
a
cerning
determination
of
age
in
Poly-
trichum.
He
says
that
the
way
in
which
Polytrichunt
reveals
its
age
is
of
the
greatest
interest
,and
the
only
example
of
a
its
kind.
The
male
fl
owers
of
this
plant
form
disc
-like
inflorescences
on
the
apices
of
the
stems.
After
fl
owering,
the
stern
regularly
grows
through
the
inflorescence
and
extends
b.67ond
it.
The
next
year
it
fl
owers
again
at
its
new
apex
and
then
develops
on
once
more.
On
such
a
male
plant
of
Polytrichuin
several
disc
-like
in-
fl
orescences
may
be
found
one
above
the
other,
and
since
only
one
flowering
disc
appears
annually
these
structures
serve
as
a
means
of
determining
the
age
of
the
plant.
Finally,
Reichardt
concluded
from
his
studies
that
the
age
varied
in
most
cases
between
three
and
fi
ve
years
and
that
only
in
very
vigorously
growing
stems
was
there
six
to
ten
years'
growth.
I
have
found
in
species
of
Polytrichunt
that
only
the
last
one
or
two
regions
of
annual
growth
were
actually
alive.
When
Reichardt
speaks,
then,
of
ages
of
three
to
fi
ve
or
six
to
ten
years
it
must
be
un--
derstood
that
he
found
that
many
regions
of
annual
growth
on
his
plants
though
they
may
not
all
have
been
alive.
In
fi
gure
2
is
portrayed
a
specimen
of
Polytrichunt
with
fi
ve
regions
of
annual
growth,
separated
from
one
another
by
fl
owering
discs.
a
a
FIG.
2.
Polytrichunt
sp.
Stem
with
5
annual
shoots
separated
by
antheridial
regions.
Original.
MULTI
CELLULAR
ORGANISMS
37
If
we
examine
the
stern
of
a
moss
plant
from
top
to
bottom
we
soon
observe
that
the
leaves
suffer
loss
of
freshness
with
age,
turn
brown,
decay
and
fi
nally
disappear,
leaving
the
stem
denuded.
The
stem,
too,
eventually
decays,
though
more
slowly,
and
out
of
this
progressive
decay
of
leaf
and
stein
from
the
bottom
up
there
e
results
an
excellent
layer
of
humus
which
makes
thrifty
growth
for
other
plants
possible.
Among
most
mosses
only
a
part
of
the
stem
is
retained
after
it
dies
but
in
many
others
the
entire
dead
stem
persists.
This
latter
condition
occurs
in
two
cases
:
1)
among
peat
mosses
when
their
lower
portions
form
a
turf
of
peat;
2)
when
the
lower
parts
of
certain
mosses
become
incrusted
with
calcium
carbonate
and
gradually
build
up
layers
of
tufa,
sometimes
several
meters
thick.
Reichardt
observed
this
latter
process
in
the
vicinity
of
the
Neuhaus
baths
near
Celje,
Jugoslavia
(formerly
Cilli
in
Steiermark).
The
tufa
was
formed
there
by
successive
incrusta-
tions
of
the
lower
parts
of
a
moss
growing
at
its
apex.
So
far
as
Reichardt
was
able
to
study
the
mass
of
tufa
vertically,
he
found
no
interruption
in
the
course
of
the
stem.
He
arrived
at
the
conclusion,
therefore,
that
all
the
layers
of
tufa
several
meters
thick
were
formed
by
gradual
progressive
incrustation
in
the
lower
parts
of
a
turf
which
was
growing
at
its
surface.
Gymnostomuni
curvirostruin
plays
a
great
part
in
this
incrusta-
tion
and
tufa
formation
and
the
extent
of
annual
shoots
can
easily
be
determined.
On
the
average,
it
is
three
lines.
The
elongation
of
this
moss,
therefore,
amounts
In
4
years
to
1
inch
In
48
years
to
1
foot
In
288
years
to
1
fathom
In
1440
years
to
5
fathoms
In
2800
years
to
10
fathoms
From
his
observations
the
author
concludes
that
this
and
other
species
of
moss
can
attain
ages
which
vie
with
those
of
very
old
trees.
Though
Reichardt's
investigations
undoubtedly.
are.
of
great
value
they
do
not,
in
my
opinion,
admit
of
the
above
-mentioned
conclusion
but
only
indicate
that
one
and
the
same
moss
stem
may
repeatedly
resume
terminal
growth
for
many
successive
centuries
When
he
says
that
mosses
may
become
hundreds
or
thousands
of
years
old
he
induces
the
misconception
that
the
moss
plant
itself
lives
that
long.
That
is
certainly
not
the
case,
for
only
the
upper
38
THE
LONGEVITY
OF
PLANTS
youngest
one
to
ten
annual
shoots
remain
alivq,
all
lower
regions
form
a
dense
mass
preserved
by
calcium
carboridte.
If
we
want
to
determine
the
actual
age,
i.e.,
the
time
during
which
life,
is
retained,
we
must
consider
only
the
last
annual
growth
regions
which
are
still
alive.
In
the
light
of
our
knowledge
so
far
no
moss
can
live
longer
than
ten
years
even
under
the
most
favorable
conditions.
PTERIDOPHYTES
Ferns.
Every
transitional
stage
may
be
found
from
the
delicate
Hymenophyllaceae,
only
a
few
centimeters
tall,
to
the
mighty
tree
-
ferns,
15
to
25
m.
in
height,
and
a
great
variety
in
age
corresponds
to
this
varied
development
in
size.
The
mere
sight
of
the
palm-
like
stems
of
Alsophila
and
Cyathea
with
their
umbrella
-like
crowns
gives
the
impression
that
these
plants
represent
relatively
great
age.
From
observations
which
I
have/made
in
the
tropics
on
the
growth
of
tree
-ferns
as
well
as
from
specimens
of
Alsophila,
Cy-
athea
and
Marattia,
cultivated
in
the
palm
-house
of
Schonbrunn
in
Vienna,
I
have
come
to
the
conclusion
that
tree
-ferns
can
live
for
at
least
several
decades.
Ferns
exhibit
perennial
growth
with
either
an
above
-ground
or
a
subterranean
stem.
They
live,
accordingly,
for
two,
or
more,
or
for
many
years.
The
greatest
age
is
to
be
found
among
the
tree
-
ferns.
An
exact
determination,
even
among
the
latter,
is
not
pos-
sible,
for
there
are
no
annual
rings
in
the
stems;
the
latter
do
not
possess
secondary
growth
and
neither
anatomical
nor
morphological
criteria
are
available
for
the
determination
of
age.
Most
ferns
produce
spores
either
only
occasionally
or
very
often
during
their
lives,
and
there
are
only
a
few
which
sporulate
but
once
and
then
perish.
Among
the
latter
are
Ceratopteris
thalic-
troides,
species
of
Anogramma
as
A.
leptophylla
and
A.
chaero-
phylla,
and,
among
pteridophytes
in
the
broader
sense,
Salvinia
natans."
In
the
case
of
certain
ferns,
the
prothallia
can
live
during
more
than
one
period
of
vegetative
growth,
especially
when
for,
various
reasons
fertilization
is
suppressed.
It
appears
to
me
very
probable
that
the
longevity
of
the
prothallium
can
be
considerably
prolonged
by
prevention
of
fertilization
through
separation
-of
male
and
female
prothallia
and
it
might
also
be
possible
to
prolong
the
life
MULTICELLULAR
ORGANISMS
39
of
the
sporophyte
by
'suppression
of
all
spore
-bearing
fronds.
Further
investigation
of
this
matter
is
very
desirable.
The
prothallium
of
Gymnograntina
leptophylla
can
prolong
its
life
and
survive
drying
periods.
It
exhibits
perennial
growth"
by
means
of
adventive
sprouting
while
the
asexual
generation,
the
fern
plant
itself,
dies
after
spore
formation.
Lycopodium.
I
have
found
by
careful
examination
that
the
shoots
of
L.
annotinum
possess
storied
structure
similar
to
that
which
has
already
been
described
for
Polytrichum.
The.
leaves
of
each
year's
growth
project
horizontally
from
the
axis,
from
the
base
to
a
region
near
the
apex,
or
they
may
be
directed
obliquely
down-
ward.
At
the
apex
of
each
year's
growth
they
are
smaller,
how-
ever,
and
are
directed
upward
into
a
small
bud.
These
buds
con-
stitute
rather
distinct
divisions
between
regions
of
successive
growth
and
the
number
of
annual
shoots
still
provided
with
living
leaves
may
be
determined
and
thereby
the
longevity
of
the
leaves
themselves
and
of
corresponding
parts
of
the
axes.
One
investiga-
tion
of
numerous
individuals
showed
that
under
favorable
condi-
tions
the
stem
was
able
to
attain
an
age
of
from
fi
ve
to
seven
years.
PHANEROGAMS
Among
fl
owering
plants,
except
in
the
monocotyledons,
the
an-
nual
ring,
which
represents
the
yearly
increase
of
wood,
provides
us
with
a
generally
reliable
means
for
determining
age.
This
is
particularly
true
when
the
annual
rings
are
sharply
differentiated
as
in
certain
native
trees,
for
example,
the
spruce,
fi
r,
pine,
larch,
oak,
elm
and
false
-acacia.
If,
on
the
other
hand,
the
annual
ring
is
narrow,
it
often
consists
of
but
a
few
layers
of
cells
and
its
thickness
then
is
only
a
fraction
of
a
millimeter.
This
is
true
of
many
trees
in
the
far
North
where
the
ring
count
is
difficult
even
with
a
lens
and
in
some
cases
can
not
be
determined
any
more
accurately
with
a
microscope.
In
ad-
dition,
many
tropical
trees
of
equatorial,
regions,
which
live
during
the
entire
year
under
rather
uniform
meteorological
conditions,
show
only
very
indistinct-
rings
or
none
at
all
and
render
the
count
very
difficult
or
impogSible.
These
circumstances
have
contributed
not
a
little
to
the
fact
that
we
do
not
possess
definite
reliable
information
concerning
the
age
of
many
trees
and
shrubs.
Reports
of
age
ofttimes
are
only
esti-
40
THE
LONGEVITY
OF
PLANTS
mates
and
undoubtedly
involve
serious
errors:
it
appears
Worth-
while,
however,
to
assemble
what
is
known
concerning
the
age
of
phanerogarns,
so
far
as
I
have
been
able
to
gather
from
the
very
scattered
literature,
for
such
a
compilation,
though
not
entirely
correct
in
many
cases,
is
of
importance
in
connection
with
the
general
question
of
longevity.
GYMNOSPERMS
CONIFERAE
Sequoia.
Among
the
longest
-lived
trees
are
the
coniferous
se-
quoias,
characterized
by
their
immense
size.
They
were
fi
rst
dis-
covered
in 1850
by
the
English
explorer
Lobb
5
°
on
the
Sierra
Nevada
Mountains
in
California
at
an
altitude
of
about
1500
m.
There
are
two
species,
S.
gigantea
and'
S.
selupervirens,.-both
in
California.
They
there
form
entire
groves
and
the
largest
of
the
trees
have
been
assigned
various
names
by
the
settlers.
Among
these
names
are
"Father
and
Mother
of
the
Woods,"
"The
Chil-
dren,"
"The
Three
Sisters,"
"General
Fremont"
and
"The
Giant
of
the
Woods."
These
trees
produce
the
redwood
esteemed
by
the
Americans
and
because
of
this
they
have
been
so
wantonly
felled
that
the
American
government
decided
to
declare
them
a
National
Monument
and
thus
save
them
from
complete
destruction.
In
moist
regions
of
Europe
which
are
not
too
cold,
as
in
the
fertile
valleys
of
Switzerland
and
near
the
are,
of
Geneva,
sequoias
are
planted
very
successfully
as
ornamental
trees.
Even
in
more
northerly
sections
rather
large
trees
may
be
found
in
wind
-pro-
tected
and
moist places.
In
the
immediate
neighborhood
of
Vienna,
in
Neuwaldegg,
I
found
a
fi
ne
tall
specimen
whose
diameter
at
the
base
was
about
two
feet,
and
while
traveling
in
California
in
1898
I
did
not
fail
to
inspect
these
biological
gigantic
wonders
near
Santa
Cruz.
Since
those
trees
are
most
worthy
of
being
seen,
ex-
cursions
are
organized
in
America
for
that
purpose.
From
San
Francisco
one
arrives
at
the
station
"Big
Trees"
in
three
and
one-
half
hours
by
train
and
upon
payment
of
a
small
entrance
fee
he
enters
a
wood
of
Sequoia
gigantea.
Though
I
had
already
become
acquainted
with
giant
trees
in
the
tropical
forests
of
India
and
Java,
I
shall
never
forget
the
impression
which
these
tree
giants
made
upon
me.
One
senses
among
them
an
astonishment
akin
to
131:11
CELLIJLAR
ORGANISMS
41
FIG.
3.
The
Wawona
Tree,
Sequoia
gig
antea,
in
the
Mariposa
Grove
of
red
-woods,
California.
Photo
by
U.
S.
Forest
Service,
42
THE
LONGEVITY
OF
PLANTS
worship
and
thinks
he
has
obtained
a
view
into
antediluvian
times.
Figures
3
and
4
give
an
approximate
impression
of
the
great
dimen-
sions
of
these
mighty
trees.
One
of
them,
knOwn
as
General
Fre-
mont,
rises
straight
as
an
arrow
for
about
.100
tn.
;
the
lowest
part
of
the
bole
is
hollow
so
that
ten
persons
can
comfortably
fi
nd
room
within
the
cavity.
Close
-by
stands
a
still
larger
tree,
taller
and
thicker
with
a
circumference
of
20
m.
A
horse
and
wagon
can
comfortably
be
driven
through
some
of
these
hollowed
trees.
These
are
by
no
means
the
largest
of
the
giants,
however,
for
'there
are
some
which
have
attained
a
height
of
142
m.
and
an
age
of
several
thousand
years.
Sequoia
gigantea
produces
trunks
which
on
the
average
are
83
to
110
m.
tall
and
3
to
10
in.
in
diameter.
One
of
these,
"The
Father
of
the
Woods,"
was
142
m.
tall
and
at
the
ground
had
a
circumference
of
36
m.
One
could
enter
its
fallen
trunk
for
a
distance
of
60
m.
and
emerge
again
through
a
knothole.
The
British
Museum
in
London
possesses
a
cross-section
of
a
tree
with
1335
annual
rings
and
the
Museum
of
Natural
History
in
New
York
has
one
of
a
tree
which
germinated
in
the
year
550
A.
D.
At
the
Chicago
exposition
in
1893
there
was
on
exhibit
a
cross-section
which
later
was
divided
into
parts
and
distributed
among
botanical
collections.
The
Berlin
Botanical
Museum
pos-
sesses
one
of
these
with
a
radius
of
2.35
m.
Careful
counting
showed
1316
annual
rings.
The
circumference
of
this
trunk
was
28
in.
at
its
base
and
its
height
is
said
to
have
been
112
m.
-
"-
Mayr
52
also
visited
the
sequoias
during
his
journey
through
North
America
and
established
certain
valuable
facts,
some
of
which
will
be
presented
here.
Without
attempting
to
fi
nd
the
biggest,
he
measured
one
in
Fresno
Co.
and
found
it
to
be
102
in.
tall.
The
green
branches
began
at
a
height
of
60
M.
and
the
diameter,
two
meters
above
ground,
was
seven
meters.
Mayr
did
not
think
that
trees
120
m.
tall
were
in
the
least
unlikely.
On
the
basis
of
a
dozen
measurements
of
annual
rings
through
the
lower
parts
of
several
trees,
he
found
that
the
average
width
of
the
annual
ring
was
1.2
mm.
This
number
divided
into
the
radius
of
the
above
-
mentioned
trunk
gives
an
age
of
several
thousand
years.
In
the
forestry
museum
of
Brussels
there
is
preserved
a
sector
which
measures
1.8
m.
from
pith
to
bark.
It
was
derived,
therefore,
from
a
tree
of
only
3.6
in.
diameter
inside
the
bark
;
during
the
MULTICELLULAR
ORGANISMS
43
1%.
A..
17r,
C.
'Fr
a
4
4
-
I
iS
t;
•11:
fps
-
e.
,a
=
7
*7"
.
fi
r
3
.
1.
4
-
3
-
At
-Ai
„,.„.:-•:,...,
•.•
4
-
Flo.
4.
The
General
Sherman
Tree,
Sequoia
gigantea,
in
the
Mariposa
Grove
of
red-
woods,
California.
Photo
by
U.
S.
Forest
Service.
44
THE
LONGEVITY
OF
PLANTS
fi
rst
decade
the
tree
grew
with
annual
rings
8
(nin.
wide;
after
the
fi
rst
100
years
the
width
of
the
annual
rings
.
amounted
to
5
mm.;
after
500
years
to
2.5
mm.
and
after
1000
year
to
1
mm.
;
at
1300
years
their
width
was
still
1
mm.
The
total
age
of
the
specimen
was
counted,
not
estimated,
to
be
1350
years.
On
the
assumption
that
this
growth
was
typical
of
all
sequoias
growing
under
similar
conditions,
he
calculated
the
age
of
the
most
vigorous
tree
which
he
measured
to
be
4250
years
and
regarded
that
age
as
quite
probable.
The
fi
ndings
of
American
investigators
are
in
agreement
with
these
fi
gures,
particularly
those
of
A/Tun
-53
who
counted
about
4000
annual
rings
on
one
trunk
10
m.
thick
and
who
estimated
the
age
of
other
sequoias
at
5000
years.
I
am
not
in a
position
to
judge
whether
the
statements
of
other
authors,
who
estimate
the
greatest
height
to
be
about
140
ii.
with
an
age
as
great
as
6000
years,
are
justified,'
for
accurate
measure-
ments
are
not
available.
However
that
may
be,
there
is,
neverthe-
less,
no
doubt
on
the
basis
of
reliable
observations
that
some
trees
may
attain
an
age
of
about
4000
years
and
are
thus
the
longest
-lived
organisms
on
our
planet
today.
Taxodium
mexicanum
Carr.
Among
the
Taxodineae
the
Mex-
ican
swamp
-cypress
attains
the
greatest
age
and
has
long
attracted
attention
by
its
great
length
of
life.
A
specimen
which
Ferdinand
Cortez
is
said
to
have
regarded
as
one
of,
the
greatest
wonders
of
America
still
stands
in
the
little
town
of
Tule
in
Mexico.
The
trunk,
measuring
more
than
31
m.
in
circumference,
one
and
a
half
meters
above
ground,
supports
a
wide
-spreading
crown
35
m.
high
and
so
large
that
its
circumference
is
about
160
m.
A.
P.
De
Candolle
ascribed
an
age
of
6000
years
to
this
tree
and
A.
von
Humboldt
attributed
4000
years
to
it.
Comparative
measurements
have
indi-
cated,
however,
that
this
swamp
-cypress
can
scarcely
be
more
than
2000
years
old,'
1
further
proof
that
estimates
alone
easily
lead
to
inaccuracies
and
exaggerations.
Taxus
baccata
L.
This
species,
formerly
very
common
but
now
becoming
scarce
and
even
probably
soon
facing
extinction,
can
attain
great
age.
Mielck
55
calls
attention
to
some
very
large
and
old
yews,
900,
1225,
2096,
2600
and
even
3000
years
of
age.
Accord-
ing
to
the
elder
De
Candolle,
there
are
yew
fr
ees
in
England
which
were
standing
at
the
time
of
the
introduction
of
Christianity.
.
11,11
.
1.11
:
11
111.1111.111.11111
ar.
toc
4
44
*IL
'
411
F/G.
5.
The
great
cypress
of
Tule.
Courtesy
of
The
New
York
Botanical
Garden.
46
THE
LONGEVITY
OF
PLANTS
1
A
thousand
-year
-old
yew
standing
in
Vienna
is
pictured
in
the
well
known
work
of
Hempel
and
Wilhelm.
56
Its
circumference
at
breast
height
is
3.07
in.
and
its
height
about
7
m.
A
time-honored
veteran
is
the
yew
at
Fortingall
in
Scotland,
whose
circumference
is
recorded
as
being
52
to
56
ft.
"'ails
tree
was
described
as
being
cleft
and
hollow
already
in
1769.
To
-day
it
still
consists
only
of
two
separate
parts
which
stand
in
a
semicircle
while
the
upper
portion
is
gone.
The
annual
rings
of
the
retained
woody
structure
are
very
narrow,
35
per
21-
cm.,
and
the
tree's
age
is
estimated
at
3000
years.
57
In
the
cemetery
at
Crowhurst
in
Surrey
are
some
yews
whose
age
is
estimated
at
1500
years.
Evelyn
58
claims
that
in
1660
he
was
able
to
measure
a
yew
tree
in
the
cemetery
of
Braburn
in
Kent
whose
circumference
amounted
to
almost
18
m.
and
which,
according
to
A.
P.
De
Candolle's
calcu-
lations,
was
2880
years
old.
Faber
59
has
presented
a
collective
discussion
of
giant
trees
and
of
old
trees
in
Europe.
Among
brOad-leaved
trees
-
the
wild
chest-
nut
becomes
very
old
and
is
followed
by
the
linden,
elm,
beech,
poplar
and
walnut.
Among
conifers
the
yew,
fi
r,
spruce
and
larch
become
very
large
and
old.
For
various
reasons
we
must
employ
caution
in
accepting
reports
concerning
maximum
ages.
They
are
usually
based
upon
approxi-
mate
estimates
and
not
upon
counts
of
annual
rings.
It
is
well
known
that
the
yew
possesses
extraordinary
sprouting
powers,
always
appearing
inclined
to
produce
spouts
from
dormant
and
secondary
buds,
especially
when
injured,
a
tendency
which
accounts
for
its
great
power
of
vegetative
propagation.
As
Lowe
6
°
has
pointed
out,
this
tendency,
as
well
as
a
method
of
forming
trunks
peculiar
to
this
species,
must
be
taken
into
account
when
judging
the
age
of
yew
trees.
All
yews
often form
a
false
trunk
composed
of
several
stems
and
the
former
appears
as
though
it
were
a
single
trunk;
its
age,
consequently,
may
be
far
over
-estimated.
According
to
Lowe,
the
yew
can
attain
an
age
of
200
to
250
years
with
a
single
trunk
and
allegedly
older
trees
have
false
trunks.
Whenever
the
intact
trunk
of
a
yew
is
shattered
or
damaged,
which
'occurs
at
least
once
in
a
century,
numerous
shoots
arise
around
-
the
base
of
the
main
stem
from
adventive
buds.
On
the
way
o
f
-
Wyndcliffe,
Lowe
found
a
yew
which,
as
is
shown
in
fi
gur'e
6,
clearly
exempli-
fi
es
this
development.
Lowe
says
that
this
tree,
30
cm.
in
diameter
MULTICELLULAR
ORGANISMS
47
ri4
FIG.
6.
Schematic
section
through
an
old
yew
at
Tintern,
England.
Around
the
dead
main
trunk
are
two
circles
of
daughter
trees
which
pre-
sumably
will
all
fuse
together.
From
Lowe.
and
about
60
to
70
years
old,
had
already
been
dead
15
to
20
years
but
was
surrounded
by
two
circles
of
younger
trees,
6
to
10
cm.
in
diameter.
The
eight
small
trees
of
the
inner
ring
leaned
directly
against
the
dead
trunk
while
the
outer
circle
was
composed
of
11
trees
somewhat
smaller
than
those
of
the
inner
circle.
The
young
trees
stood
so
close
to
one
another,
however,
that
in
the
course
of
50
to
60
years
he
expected
them
to
grow
together
into
a
single
trunk.
The
diameter
of
this
trunk
would
then,
according
to
cus-
tomary
calculations,
indicate
an
age
of
about
400
years
while
actu-
ally
it
would
be
only
150
years
old.
The
total
diameter
of
the
group
at
that
time
was
1.45
m."-
Cupressus
sempervirens
L.
This
tree,
so
strikingly
character-
istic
of
the
Italian
landscape,
is
native
to
northern
Persia
and
the
eastern
Mediterranean
region,
having
extended
its
territory
pro-
gres§ively
more
and
more
eastward.
It
grows
very
slowly,
attain-
ing
great
dimensions
and
an
age
of
2000
to
3000
years.'
Old
trees
are
over
50
m,
tall
and
up
to
3
m.
in
diameter.
"The
old
trunks
in
Giardino
Gusti
at
Verona
are
;
there
are
200
of
them,
many
of
which
are
400
to
500
years
old
and
some
of
them
reach
a
height
of
40
m.
Other
Well
known
specimens
are
the
giant
cypresses
at
the
Villa
d'Este
at
Tivoli
near
home,
at
the
Alhambra
in
Spain
and
in
burial
grounds
of
Constantinople.
Springer
says
there
are
sev-
48
THE
LONGEVITY
OF
PLANTS
eral
cypresses
around
Lago
Maggiore,
620
years
old
and
10
in.
in
circumference
in
the
lower
portions
of
their
trunks.
He
states,
furthermore,
that
a
large
specimen
in
Somma
near
Vesuvius
had
already
become
a
stately
tree
in
Caesar's
time.
hrist
63
mentions
a
tree
3.8
m.
in
circumference
near
Lugano
and
Grisebach
64
notes
two
others
more
than
1000
years
old
at
the
cloister
of
Lavra
in
Athos.
,,65a,
b
Juniperus
communis
L.
Freymann
calls
attention
to
the
largest
juniper
in
the
parish
of
Ermas
in
Livonia,
a
tree
which
stood
in
the
open
near
an
old
sacrificial
site.
Its
circumference
was
24
in.
and
its
age
estimated
at
2000
years.
Thirty
years
ago,
after
it
had
begun
to
dry
out,
the
tree
was
broken
by
a
storm."
Junipers
300
years
old
are
more
frequent.
A
specimen
48
mm.
in
diameter
in
the
woods
of
the
northern
Taunus
mountains
was
found
to
show
108
annual
rings.
A
Norwegian
specimen,
33
mm.
thick,
was
297
years
old
and
another
on
the
Kola
peninsula,
8.3
cm.
thick
at
the
base,
was
544
years
old.
67
'
Juniperus
nana
Willd.
An
old
specimen
at
an
elevation
of
2600
in.
in
the
Alps
was
103
years
old.
66
Abies
alba
Mill.
Noggerath
reported
in
his
work
of
1847
on
the
origin
and
development
of
the
earth
that
a
fossil
coniferous
trunk
(fir?),
11
feet
in
diameter
and
with
792
annual
rings,
was
found
in
the
lignite
deposits
of
Friesdorf
near
Bonn.
Mielck
69
describes
fi
rs
300,
400
and
500
years
old.
According
to
Wilhelm,
7
°
these
trees
can
become
1.5
is
thick
and
200
to
400
years
old.
Other
fi
gures
ascribe
ages
even
as
great
as
800
years'n
and