Some
observations
sulphate
in
on
barium
*
Spirogyra
D.R. KregerI and H. Boeré
Botanisch
Laboratorium
Laboratorium
en
Rijksuniversiteit,
Ultrastructuurbiologie,
voor
Groningen
SUMMARY
The
dry weight
were
is
corrected
in the
present
their
as
a
=
face
A
8.87
material
the
in
of
allowed
dry-weight
the
crystallites
tion
of
BaS0
4
of which
extension
to be
Electron
0.9
crystallite
latter.
The
with
long
p.
an
in the
evidence
of the
periphery
living
found
were
cell
and
be
to
of the
visible
4
mainly rect-
about 0.17
as
On
p
indicated
unit
and
cytoplasm.
paper
the BaSG
has
the
inter-distances,
size an estimation has been made of the
crystallites
that
average width
Presumptive
at wide
occur
of an even distribution in the
in the
has shown
It has the form of individual,
0.48
x
earlier, preliminary
an
microscopy
crystallographic plane containing
concluded, mainly
content and
in case
%.
is about 0.3
p.
the
in
Spirogyra, reported
A. Generally, they
5.45
=
in
up to about
ranging
greatest
4
at 0.4-0.7
and not in the cell wallt.
majority
size
and b
the
determined
protoplasm
angular prisms,
and variations
of BaS0
percentages
and
cell
far
axes
the
as
the basis
of
distance between
degree
under
of accumula-
the
polarizing
microscope.
1.
INTRODUCTION
In
a
brief note
results
of
the
on
of BaS0
occurrence
in
fungi
4
have
experiments
some
been
reported
and
algae (Kreger 1957)
obtained by R. Frey in residues of extraction of fungi (Frey
tamination introduced
observation
made
produce X-ray
It
was
diffraction lines
4
the
Although
were
and woods
(Ellis
is
and in
unusual,
something
size of its
its
to
the
the BaS0
first
in
cell walls
*
Dedicated
4
1950)
the
was
other
of dried
a con-
the
hand,
Spirogyra
could be confirmed.
4,
be isolated from the
plants, probably
particular
BaS0
had
in certain
quantities
algae,
as
crops
sulphate,
(Robinson
like those found in
been found before. The
not
4
several
questions.
questions
algae,
problem,
In the
isolated
by
18(1),
Febr.
concern
which will
not
and
dry
first
place,
one
has been
1950)
c.s.
Spirogyra
observation,
would like
to
its role in the life of
a
form
part
physical
van
1969
Spirogyra
and
be considered here.
it has been noted
probably
to Professor Dr. G.
Acta Bot. Need.
in
its presence in
Other
in other
would
4
to
On
samples
the
BaS0
about the location of the substance in the cells and about the
particles.
occurrence
As
algae
gave rise
therefore,
that
those of BaS0
actually
of barium in
instances,
1965),
resembling
can
procedure.
Nicolai,
E.
the
determined.
occurrence
established in other
extraction
by
shown then that BaS0
weight percentages
know
the
by
originally
that
indicating
already
of the cell
in
our
contents
cleaning procedure
earlier
paper
because it
from
a
was
that
absent
suspension
of
Iterson.
143
D.
crushed
whereas
cells,
that cell wall
duced
Therefore,
the
by
the
by
lines. Moreover,
4
do
to
electron
as
small
A research
visible
this
ponds
was
and
reported
not
were
works)
note
AND
here,
and
will
data of the
they
mainly
and those
then
protoplasm
provide
con-
the wall
or
or
crystallites.
examine in the first
alcohol.
70%
of its
visible in the
If the
by
instance,
crystals
were
satisfactory
more
are
fully
be
discussed
earlier work.
in
connection with
Since
the
latter
data
the
were
mentioned in the present paper.
at
of the
Haren-Gr of the
works of The
water
botanical
of the
gardens
of
University
about 60
u,.
and
place
outdoors.
2.1.
Preparation
The
stored
samples
in
70%
of clean
cell
were
examined
ethanol
or
of
were
kept
in
and
Hague
Delft
Groningen.
determined and varied in filament thickness from about
to
cool
garden
Institute
species
165 jj.
(water
homogeneous
filament
containers
concrete
of
The
at a
walls
Native walls
Clean, native walls
blendor until
cells and
contents
beads about 230
the
was
from
living
broken cells.
diameter.
and
removal
These
plasma
were
separated
in
a
was
no
all
use
of
on
the
than
a
two
centrifuge
Mickle shaker with
slightly
samples
treated in
longer
the wall material
in which the
debris. Not
of
pieces
by shaking
Subsequently,
centrifuging,
of
material which
obtained containing
and then crushed further
by repeated washing
promoted
prepared
were
suspension
a
three whole
from cell
glass
to
proof
were
easily
This could
investigate,
to
collected from basins of the
thickness,
2.1.1.
possibility
be
to
METHODS
ditches,
Technology
undertaken
was
means,
details of their distribution in fresh cells. The results of the
omitted in the brief
Spiro gyra
the
experimental
MATERIAL
X-ray diagrams
opaque spots.
from which
wall,
procedure.
suspected
material stored in
simplicity,
are
the
were
distinct
a
of the walls.
gained by physical
its presence in either the
these lines
techniques,
and
latter
with the
something
data about the size of the
as
would open
former step
results
well
as
along
sake of
the
these revealed
tangential plane
beads involved in the
electron
as
the
to
preparations
molecule and
crystals,
concerning
in both of them,
for the
glass
heavy
a
microscope
clusive evidence
fixation
with
shaking
the observation
by
chemical extraction of the filaments pro-
with reference
have
fraction from the
contradicted, however,
BaS0
crystallites
particles might
Since BaS0
is
4
presence
or
be
could have been removed in the
they
2.
to
obtained
with
X-ray diagrams
KREGER AND H. BOERE
present in the protoplasmatic
was
preparations
orientation of the
e.g.
it
This seemed
suspension.
same
R.
was
collected
alkaline
could be
water
fully
freed
from the latter.
2.1.2.
Walls cleaned
by
extractions
Another method started with material stored in
heated in 96
144
%
ethanol
at
60 °C for 1
hour,
70%
ethanol. The threads
after which the alcohol
Acta Bot. Need.
was
18(1),
were
decanted
Febr.
1969
BARIUM SULPHATE IN
SPIROGYRA
and
mixture ethanol-acetone
replaced by
a
on
reflux for 15 minutes. This
of
bleaching attained,
with
3%
NaOH
until it
KOH
or
2.2.
Determination of BaSO
mixed with
dried,
added and
a
free of
sulphate,
2
4
The accuracy of this
two
ner
with CaC0
Ca
3
proportion
3
,
1:1
(P0 4)2
In
about 2:1.
was
tative
was
washed several times with
of Na C0
equal quantities
2
17.7 and
yield
4
was
for
standing
The
3
and
was
water
warm
K C0
2
washing
3
until
precipitated
by
in the
same man-
respectively
and starch and peptone in the
each,
of BaSQ
by treating
16.6 mg of BaS0
4
4
12.0 mg in both
was
of BaS0 in
4
content
the
some
weeks
Spirogyra
an
cases,
the ratio of the
two
correction
factors,
dry weights
alcohol
of BaS0
of the
by evaporation
in material from
4
and
2/3
stored in alcodissolved in the
protoplasm
material obtained from the
Therefore, dry weight percentages
analysis.
warm
1916, slightly modified.)
determined
10 mg of
,
and
water
be corrected for fresh material and for losses
to
nearly empty
bath. Water
on a steam
HC1 from which BaSQ
was
The
dry weight
filament fraction and
alcohol had
evaporated
be accounted for that part of the
to
alcohol. In flasks
g.
degree
treatment
washed with
porcelain crucible,
a
and
by mixing
MgS0 4
boiled
the
70%.
the
determining
the fact had
,
make 3
to
average therefore of
hol,
procedure
samples prepared
A further
bath gave
on a water
Artis & Maxwell
(After
.
dependent
white.
after extraction with
melt,
dissolved in
was
addition of H S0
regia
then melted with
was
crucible. The
platinum
ashed in
was
aqua
to
was
content
after which it
evaporated,
until neutral. It
in
material
weighed, dry
water,
repeated,
on
material.
granular
4
The
100 °C
at
some
in which the material
light yellow
was
solution
cells, usually still containing
1:1,
sometimes
was
during
the
10/7 respectively,
quantinearly
neutralize each other.
2.3
diffraction and
X-ray
X-ray
diffraction
radiation
mators
was
40
The
40
glass
mm
Ryter
to
with
or
a
microscopy
flat-film
camera
thick in the beam
0.25
cut
at
were
45°,
mm
and Ni-filtered CuKa
direction, using pinhole
diameter. The
and
microscopy
specimen-to-film
in which
were
a
found
out
introducing
clearance
colli-
distance
were
heavy
angle
on an
of
4°,
a
in
Vestopal
section.
Generally,
expected
metal
to
might
be
W
LKB-Ultrotome with
speed
of 1.0
mm/sec.
be favourable. With thinner sections
to
of the
crystallites
embedded
were
and sectioned
Kellenberger
pushed
because the
themselves,
electron
and
feed of 900 A
applied
mm
and 0.5
for
specimens
crystallites
3.
long
electron
out
mm.
knives
a
0.5
specimens
on
according
and
carried
was
no
highly
metal
most
staining
was
electron opaque
obscure their
by
perceptibility.
RESULTS
3.1.
X-ray
diffraction
X-ray diagrams demonstrating
Acta Bot. Neerl.
18(I), Febr.
1969
the presence of BaSQ
in
4
Spirogyra
are
shown in
145
D. R.
Fig.
1.
Quadrants
of
X-ray powder
demonstrating the
a.
b.
c.
d.
Fig.
2.
Extracted with
Ashed
alcohol
Commercial
X-ray diagram
by
normal
to
positions
arcs
are
and
H S0
2
sample
of
a
4
in
page.
of
with
aqua
HCI solution
4
of the
in
several
stages
of
treatment,
are
regia,
of carbonate
melt,
.
parallel
Layer-lines
Spirogyra
BOERE
.
stack of flattened
centres
cellulose
4
H.
acetone,
of BaS0
extraction. Beam
of the
diagrams
of BaS0
after extraction
sample
Precipitate with
moved
146
presence
KREGER AND
cell
to the
indicated
arcs
walls
from which
walls,
in
of enhanced
the latter
one
the
quadrant,
intensity
in
contents had
parallel
with
to
equator
the
the BaSQ
4
been
and
re-
nor-
corresponding
rings.
The broad
reflections.
Acta Bot. Neeri
18(1),
Febr.
1969
BARIUM
SULPHATE IN
I.
fig.
It is evident that the diffraction
correspond
with those of
2 represents
Fig.
2.1.2. and
to
the
SPIROGYRA
filaments
of
direction
a
in
suspended
were
4
X-ray diagram
an
irradiated in
in the various stages of
rings
of commercial BaS0
sample
a
parallel
thin,
coherent layer, in which the cell walls flatten
such
layers
1
dicular
in the
thus
of fig. 2 is
diagram
shows
cutting
parallel
a so
called
to
the
rings
come
BaS0
position
to
orientation of
uniplanar
BaS0
crystallites
and
arcs
orthorhombic with
question
direction
provided
by
the
axes
mentionedin table 1.
are
mm
of
rings
indices of the
1. Data
men
in
from
of the
specimen.
2
fig.
The
d
a
=
(Smith
8.87 A
indicated
=
of the
position
are
plane (002)
similarly
—
The
crystals
5.45 A and
with
plane
orientation
spacing
2/ 40
=
spacing
d
(from
in
A,
indi-
diameters in
hkl
Smith
=
Miller
1960),
n
used to determine
the
crystallite
orientation
of BaS0
4
in
the
speci-
hkl
n
4.35
Oil
i
3.90
111
i
37.0
3.58
002
2
(merid.)
38.4
3.44
210
0
(equal.)
40.4
3.32
102
2
43.6
3.10
48.9
2.83
112
51.4
2.73
020
bic, they
are
or
of the
211
layer-line
that the axis
c
has
the cell wall surface.
oriented with the
Acta Bot. Neerl.
18( 1),
Febr.
=
the text.
33.5
specimen
A.
7.15
be derived
can
ring
are
=
c
from
29.7
correspondence
is
data of
crystallographic
follows:
as
d
interpretation
in
arcs
has in its walls cellulose
1960).
b
corresponding
incident beam and the equator of the
the
The
arcs.
question. Explanation in
2/40
of the
are
arcs,
crystallographic
layer-line position
Table
They
with distinct
in-
equator,
while those which
determined
known
from which the
diagram
strip.
the
to
in the
perpen-
distinctly
,
The data
a
The equator
of
arcs
in which the
be
can
the
mentioned in the A.S.T.M. data file
be
a
with reference
crystallites
form
Several of
glass.
1957).
(Kreger
intensified
the
purpose
to
direction of the
spacings,
in
surface
leaflet faces.
crystallites
BaS0 4
4
to
the
to
from cellulose micelles. The
4
cated
to
according
that
adhesive. A strip, about
an
longitudinal
Spirogyra species
wall surface
of the
position
the
to
correspond
The orientation of the
the
parallel
symmetrical
a
the latter indicates that the
parallel
and
out on
as
For
glass
a
and irradiated in
definite orientation of the
a
diffraction
somewhat broadened
with
gum arabic
some
of the stack
out
on
diffraction rings all of which exhibit
with
intensity,
revealing
sharp
with
cut
the direction of
to
creased
then
was
diagram
The
heaped
were
wide,
mm
the walls.
to
and dried
water
filaments cleaned
Spirogyra
treatment
.
1969
a,
number
a
n
1
2
0
with the Miller-index I allows
preferential
diagram,
Hence,
orientation normal
i.e. normal
since the
6-plane parallel
tot
to
to
the
the leaflet plane
crystallites
are
of
orthorhom-
the wall.
147
D.
3.2.
Electron
At first
sight
opaque
one or
3.
in
but
remnants
Fig.
of
a
a
micrographs
a
section
shrunken
of
b.
c.
a
of
contained
crystallites
the
about 3000
20
x
some
4
by
there
or
of
AND
H.
BOERE
a
BaS0
4
but careful
expected,
small
individual,
and
distribution in the order of
they appeared
was
a
small
as
undamaged
hole
the knife. Also empty holes
containing
were
observed
crystallites,
Note their connection
crystallites.
with electron
with
be
to
presence
A,
Sometimes
ja.
trapezia,
protoplasm. Top right:
chloroplast
Fractured
as
showing
part
of the cell
transparant
core
wall.
and
with
Bottom
empty
the
right:
holes
periphery
cross
which
of
section
presumably
starch.
crystallite
Two
empty holes,
have
been
pushed
d. Two well formed
148
of them
fractured
crystallite
Part of
have
cases
show the
not
some
field about 20
in other
Electron
a.
in
crystallites, measuring
two
prisms,
KREGER
microscopy
the sections did
revealed
searching
R.
at
with
high magnification.
scratches
due
to
Note
knife
contact with
damage
caused
plasma
by
the
membrane.
crystals
that
out.
prisms.
Plasma
in this
case
stained
with
uranyl
Acta Bot.
NeerL
acetate.
18(1),
Febr.
1969
BARIUM SULPHATE
where
SPIROOYRA
had been
crystallites
heavily
and
scratched,
situated in
frequently
of the knife
damage
As
IN
edge
In
contents.
a
the
on
proof
as
instance
its
or
that
Some
crystals.
were
the
examples
were
it
found,
was
scratches
was
caused
were
by
shown in fig. 3.
are
they
all present
were
observed in
crystallites
any
Most sections
remnants
it may be noted that
crystallites
no
of the section.
out
crystallite
scratch
a
the location of the
to
in the cell
fully pushed
where
or
the
on
wall.
Measurements of width and
showing
curves
in which
A,
the half
and for the
15%
pezia,
The
and
as
crystals
Although
plasts
8%
rhombs and
as
outside
the
on
with
the
characterized in the
are
grains.
metal
By
empty holes. It is
penetrate the
starch,
and
sections
floated
on
were
of this
chloroplasts
have
that
by
a
number of
a
of
the
20
%
total.
as
tra-
round.
stands
well
reasonably
out
Most
chloroplasts.
membrane
may
account
on
of
by
core
of
these
surrounding
of their
they
had
come
is
which
very electron
shape
not
shown
slightly
from
more
be
to
been able
the
to
when the
disappeared
free
trans-
reminiscent
are
were
medium had
swelling,
to
be noted that the chloro-
large,
sections
some
surface
water
it
ring
embedding
this,
round
nearly
a
were
10%
rectangles,
as
were
staining,
paper,
sections
that the
a
about
lengths,
1400 A and 3000
at
clusters and membranes elsewhere in the cell.
shadowing
supposed
few
inner side of the
parent spots in their periphery, which
of starch
2800 A for the
and retraction around the
plasma
scope
at
found
were
sections
a
distribution
crystallites yielded
In addition there
in the
the absence of any
despite
contact
60
A, representing
7500
X
crystals appeared
observed
in
or
some
2000 A and 4500 A.
strong plasmolysis
a
were
clusters
at
squares,
plasma,
shows
of
numbers for the widths
around 4500
of the
%
length
1700 A for the widths and
at
peak
lenghts
bigger crystals
About 55
peak
a
knife.
electron
The
trans-
parent than its surroundings.
3.3.
A
Dry
survey
given
Table
in
2.
of BaS
weight percentages
of the
most
O4
representative
determinations of the
BaS0
content
is
4
table 2.
Dry weight percentages
time in
sample
1
of BaSD
4
found
in
some
samples
dry weight
BaSOj (in mg)
(ing)
precipitated
alcohol
of
in
Spirogyra.
%
of
in
%
corrected
dry weight
2 weeks
4.55
20.6
0.45
0.43
2
2 months
4.08
18.00
0.44
0.42
3
fresh
1.03
3.0
0.29
0.415
4
2 weeks
1.35
10.5
0.78
0.75
Samples
1, 2 and
about 165 (j. wide,
three months in
3
in
an
outdoor
tions: 198 mg clean walls
836 mg cell
contents
Acta Bot. Need.
table 2 refer
collected from
18(1),
container,
prepared
obtained
Febr.
water
1969
as
to
a
Spirogyra
works
basins.
and the
species
with filaments
No. 3 had been
sample
consisted of
indicated under 2.1.a. in the
by evaporation
of the
collected
kept
two
methods,
washings.
for
fracand
The
149
D.
BaS0
content
4
determined in the
was
negligible quantity
with much thinner threads, collected from
It contains
2 refers
fig.
4.
BaS0
more
than do the
a
other
to
and the
only
a
different species
a
ditch in the Delft botanical
samples,
H. BOER 6
in which
separately,
4 refers
Sample
4
material from the
to
fractions
two
found in the walls.
was
AND
R. KREOER
gardens.
of
X-ray diagram
batch.
same
DISCUSSION
Since BaS0
electron
for the
reason
tained
of
diagrams
fore in their
The
their
place,
of
which the
this
which
they
crystals
plane parallel
the
to
remain
crystal
to
offig.
the wall. In the second
former
enable
a
dry weight
crystallographic
extension,
might
in
length
3000 A
A,
i.e. with
1700
x
length
A
about 7500
contents
about 0.15 p
types
each
are
in the
group in the
crystals,
Neglecting
cell
the
volume
these
3
.
a
If
10%
square
the
of the
of the 0.45
while these
physico-
the interfibrillar
or
chemically
in
(001) and,
inert
very
we
one
in the cells and the size of the
made of their
and
with
a
basal
9
x
%
BaSD
x
about
plane
A,
4500
is
as
crystals,
quantities
a
crystallite
i.e.
indicated
with
a
the
by
the numbers of the
of BaS0
4
represented
or
by
1:2.
roughly
of the cells is present in the form of the
about 90
enables
small
basal
0.009:0.15, i.e. about 8:15
4
this
4500
comprises,
total number of
size-groups,
two
the other with
,
plane of
and the
square
3
distribution in
mean
may be devided into
about 0.009
p
represent
large crystals
be
latter group
proportion 9:1,
containing
further calculation
weight
of
0.15%
BaS0
algae
specific
weight
taining
150
drying
some
an
and
crystal
of the total number of crystals.
%
estimate
of the
be made of the
to
mean
mean
between
distance
crystallites.
In the
the
a contents
proportion
Therefore, only 1/3
smaller
about
and
measurements, about
two
of
with
4
to
crystallites
ranging
be
plane
account
on
predominates
is
of BaS0
content
calculation
rough
the cell. For that purpose the
1700
BaS0
there-
sought
possibility.
The data about the
crystallites
one
which
4,
the
by
be twofold. In the first
or
there
4
the
prefer
and the BaSD
wall,
would evoke the orientation. Since
hence,
be
to
ob-
specimens
and in fact
in the empty cells.
chemical interaction between the oriented cellulose micelles,
matrix substance of the
3 in table 2
the process of
during
place,
wall
2,
has
captured
face of greatest
would orientate themselves
observed
never
sample
in cell
6-plane
a,
were
form part of the wall. The
not
crystallites might
i.e. the
orientation,
(001), might correspond
wall,
fraction of
X-ray diagram
of the orientation of the
plane
wall
similarly prepared specimens,
insolubility, by
reason
the
against
crystallites
4
shown in the
as
number of
a
of BaS0
presence
by extraction,
or
the cell
may conclude that it does
we
4,
only
wall,
and
micrographs,
free of BaS0
was
in the cell
crystallites
4
in the
4
is
no
for the
weight of
more
crystallite
to
BaS04
will
is
not
of 0.009
4.48,
into
of the
consideration that
fresh
1,
we
we
and
weight,
for the fresh
0.0075%
for which
be far from
3
p
take
%
becomes
dry weight
of the fresh cells
one
have
we
than about 5
take
4.5,
the
dry
therefore
weight.
and the
Since
specific
find for the volume V
con-
:
Acta Bot. Need.
18(1), Febr.
1969
BARIUM
SULPHATE IN
SPIROGYRA
The above
the
occupy
to
a
of
cube
a
crystallites
The chance of
tioning
would
outcome
centre
between the
0.0075
X
V/100
can
be calculated
does
crystallites
not
3
0.009 (i.
X
that
mean
about 8
8
of
on
similar
a
18
18
X
seem to
p, i.e.
of BaS0
around 0.5
4
would
distance
calculated
%
of
ease
by
sec-
in
magnifi-
x
detecting
the
practice.
thataS/wogyracellof
would contain
with
-
a
number of crystallites in the order
a
-
size
corresponding
10.000
at
experienced
was
easily
field
a
of the
picture
average dimensions, say 80 p diameter and 500 p long,
content
mutual
distribution and
18
X
be far from what
From the above data it is furthermore
dry weight
the
photograph
cm
about 1 in 5. This
at
and
.
crystallites
p.
a
section field of 18
a
540 p
=
distributed
8 [i,
x
3
V
or
,
evenly
x
would then be 8
normal field of view
cation,
4.5
hitting crystallites
1000 A feed in
at
=
of 5000.
A
last
question
in
of the
with the
compared
BaS0
of interest
point
forms the
to
consider
concentration in
the
of 20 °C is indicated as 2
water
4
Spirogyra,
of 0,022
BaS0
0,037%
-
of these
scope
BaS0
calculations
in the
cells
as
4
data of table 2 for fresh
content
within the
of accumulation of the
degree
i.e.
environment.
mg/liter
with
in the
4
4
2
living
cell
as
the
of
solubility
and conversion of the
%,
of 95
content
there is
cells,
the substance per unit of volume in the
or
water
a
Since
be
can
leads
%,
110-185 times
to
a
much of
as
maximally present
in the environment.
Because the size of the
limit of the
visible
taining
ing
this
by
BaS0 4
according
to
we
time this
cell and
are
in
very
these
connected
be
this respect
raised whether
that
was
a
they
Spirogyra
when examined under the
small,
highly
birefringent
are
con-
polarizin
particles
after rotation of the filaments. Once
particles
seems to
to
somewhat above the resolution
or
concentrated in the lower part of the cells and
were
position
observation
not
near,
could also find them under
for doubt that
reason
same
look
is
question might
X-ray evidence,
many,
They
reassumed this
the
experience
to
showed
movement.
gradually
where
Our
means.
microscope,
Brownian
crystallites
light microscope,
any
were
phase
the
heavy
indicate that
There is
contrast.
BaS0
4
they
knowing
hardly
freely moving
are
any
At the
crystallites.
in the
organelle system.
REFERENCES
B.
Artis,
& H.
L.
(1916):
Maxwell
Barium
in tobacco
and
other
plants.
Chem.
News
114:
62.
Ellis,
E. L.
Frey,
(1965): Inorganic
elements
of wood.
In:
W. A. Cóté
of Woody Plants. Syracuse University Press, Syracuse,
ture
(1950):
R.
Kreger,
D. R.
Chitin
und Zellulose
(1957a): X-ray
in Pilzzellwanden.
interferences
of BaSO, in
Ber.
fungi
N.
Jr.,
Y.,
ed.:
Cellular
Ultrastruc-
181-189.
p.
Schweiz. Bol. Ges.: 60;
and
199-230.
algae. Nature (London)
180:
867-868.
—
(1957b):
New
crystallite
orientations of cellulose
I in
Spirogyra
cell
walls.
Nature
(London)
180:914-915.
Robinson,
soils
Smith,
W.
and
O.,
R.
plants.
J. V. ed.
R. Whetstone
U.S.
Dept. Agric.
(1960): X-ray powder
& G. Edginoton
Tech. Bull.
data
file,
1013:
Sets
(1950):
The
occurrence
of barium
in
1-34.
(1-5),
Revised.
Am.
Soc. Test.
Mat., Phila-
delphia.
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18(1),
Febr.
1969
151