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PLANT CELLS AND LIVING MATTES.
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Plant Cells and Living Matter.
By
Louis Elstoerg, M.O.,
of New York.
To botanists biology owed its first knowledge of ultimate
Structure and of living matter. The names " cell" and " protoplasm" testify to the epoch-making researches of Schleiden
and Von Mohl. And in accumulation and classification of
further biological knowledge botanists have taken so prominent
a part that even those of us who are interested only in animal
morphology have had to keep some track of the labours of
Nageli, Pringsheim, De Bary, Hofmeister, Sachs, Prantl, Strasburger, and many others. It is all the more remarkable, therefore, that the investigations carried on during the past decade,
which have resulted in proving that all the so-called " cells"
constituting animal tissues are interconnected by filaments of
living matter emanating from these " cells," seem to have
borne no fruit for the study of plants. It was in the hope of
being able to repay histological botany for some of the light it
has thrown on animal histology that I engaged in the researches,
the account of a few of which I am about to detail.
A small portion of a delicate blade of grass, cut off with a
pair of scissors, transferred to a slide together with a drop of
dilute glycerine (two parts of pure glycerine and one part of
distilled water), was examined with a power of 1200 diam. I
had at my disposal for these examinations two excellent immersion lenses, made respectively by Tolles, of Boston, and Ve'riek,
of Paris. In some parts, in tvichomes, stomata, air-vessels
&c, nothing more could be seen with such amplification than
with comparatively low powers of the microscope ; the epi-
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dermal fields as well as the surrounding frames of cellulose
appeared structureless, or at most only very indistinctly granular.
The main mass of tissue enclosed by the epidermal system, the
parenchyma, presented blunt polygons separated from each
other by a shining narrow rim of cellulose, and containing
numbers of chlorophyll-granules. Some contained only very
few and very small such granules, surrounded by an extremely
delicate uncoloured reticulum, of which the filaments were of
about the same breadth as the points of their intersection. In
some polygonal fields there were a number of coarse chlorophyll-granules interspersed in a network, the threads of which
had points of intersection that were thickened so as to constitute distinct though not green minute granules, while in other
fields there were so many coarse and smaller green granules
that they nearly completely filled up the polygon. Under all
circumstances, however, the granules, closely focussed, appeared
stellate, and were interconnected by means of delicate filaments running in large numbers from each granule to all its
neighbours. If of small size a chlorophyll-granule appeared
homogeneous, of a comparatively higher lustre, and of less
intense green colour; larger granules exhibited an indistinct
reticular structure in their interior; the largest showed- the
reticular structure very plainly, and not infrequently in the
centre a small shining body was observed sending radiating
spokes toward the periphery, inosculating with a thin wall that
enclosed the granule in toto. Toward the apex of the blade
the granules became fewer in number and smaller in size; at
the apex there were no chlorophyll-granules.
In fig. 1 are represented chlorophyll-granules (CHX.) interspersed in the reticulum ( R ) , surrounded by the cellulose
frame (c).
These observations show that the vegetable living matter
enclosed by the wall of cellulose is arranged in the form of a
network, and that a similar reticular arrangement exists in the
chlorophyll-granules. It is well known that chlorophyllgranules are themselves minute masses of the living matter of
plants, coloured green by a colouring matter, to which the
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name chloropbyll is given. Living matter has been called by
Hugo von Mohl " protoplasm/' by Lionel Beale " bioplasm,"
FIG. 1.—Cells from blade of grass, showing—CM. Chlorophyll granules.
R. Reticulum of protoplasm, and 0. Cell-wall.
and by me, because etymologically more correct, " bioplasson."
I am no stickler for new names, but in scientific discussions
we should use, if possible, correct names; and of the four
synonymous designations, viz. living matter, protoplasm, bioplasm, and bioplasson, I therefore confine myself generally to
the first and last, although the term protoplasm is best known
and by others most used.
In the year 1873, in a communication to the Vienna
Academy of Sciences, entitled " Phases of Living Matter,"
Carl Heitzmann first described, in Amoeba, the youthful condition of masses of living matter as being constituted by homogeneous granules, and advanced stages as being characterised
by vacuolation followed by reticulation. These statements
were confirmed as regards vegetable organisms in a paper on
" The Structure and Growth of some Forms of Mildew," in the
' New York Medical Journal/ November, 1878, by William
Hassloch, who says lhat the first visible form elements of the
plant are homogeneous granules, and the first appearing buds
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DR. LOUIS ELSBKRG.
compact projections, either globular or elongated, the first
differentiation consisting in the occurrence of a central vacuole,
while after a certain development has been attained the plant
protoplasm appears in the form of a network.
Many botanists have observed and described reticulated
living matter, not only when in its naked condition, as plasmodium, as it is called, but also when enclosed in a cellulose
wall. Allow me to cite a few examples : Sachs has figured " a
cell of Zygnema c r u c i a t u m , with two stellate chlorophyllbodies which are suspended in the interior of the cell; they are
united by a colourless bridge of protoplasm in which lies a
nucleus; the rays which form the union with the parietal sac
are already nearly colourless in the middle. In each of the
two chlorophyll-bodies lies a large grain of starch (amplification 550)," also " forms of the protoplasm contained in cells of
Indian corn (Zea mais); A, cells from the first leaf-sheath of a
germinating plant, showing the frothy condition of the protoplasm, i.e. the many vacuoles separated by thin plates; B, cells
from the first internode of the germinating plant; the protoplasm is broken up into many rounded masses in each of
which there is a vacuole (b) y these are the so-called ' sapvesicles.'" Sachs has also figured "parenchyma cells from the
central cortical layer of the root of F r i t i l l a r i a imperialis,
longitudinal sections, A, very young cells, lying close above the
apex of the root, still without cell sap or vacuoles. B, cells of
the same description about 2 millimetres above the apex of the
root; by the entrance of cell sap the vacuoles s, s, s, have
been formed, c, cells of the same description about 7 to 8
millimetres above the apex of the root," in one of which the
reticulum is very plainly seen. Bessey says " in the stamenhairs of T r a d e s c a n t i a V i r g i n i c a the protoplasm forms a
rather thick layer over the inner surface of the cell wall, and
in some part of this layer the nucleus lies embedded. From
the nucleus, and from various parts of the protoplasmic layer,
there pass to the opposite side of the cell thicker or thinner
bands and strings, and gives a figure of the same after Hofmeister. Prantl has figured Meristem cells of the stem of
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Vicia faba in which filaments of living matter emanating
from the nucleus go to the peripheric layer of living matter,
and also hairs from the epidermis of ovary of C u c u r b i t a , in
some of the compartments of which the reticulum is very distinctly shown with quite low power (x 100).
Heitzmann, the discoverer of the reticulum of living matter
and of its continuity throughout the entire animal organism,
states in his magnificent work just published, entitled ' Microscopical Morphology of the Animal Body in Health and
Disease/ p. 57, " My own limited researches enable me to
assert that the granules of living matter iu vegetable protoplasm
are, as a rule, united in the shape of a reticulum, in the same
manner as in animal protoplasm. Besides, the researches of
W. Hassloch elucidate the identity of both animal and vegetable
living matter in a satisfactory manner. I may add that all cells
of the vegetable organisms are uninterruptedly connected by
means of delicate offshoots piercing the walls of the cellulose.
The granules of amylum are transformed living vegetable
matter. The plant in toto is an individual and not composed
of individual cells." But demonstration of this statement is
wanting. Low powers of the microscope, and even high
powers, show that a less or more thick cloak of cellulose surrounds each plant e i cell," and separates it from its neighbours.
The observations of the chlorophyll-granules and of the interior
of the polygonal cellulose frames of blades of grass herein detailed, while they fully bear out the assertions of Heitzmann
and Hassloch as to the reticular structure, and perhaps even as
to the growth phases, at least so far as dimension is concerned,
of masses of living matter of plants, do not advance our knowledge much further. All my endeavours definitely to determine
whether the plant " cells" are interconnected or not were
unsuccessful with the means I employed in both transparent
specimens and in sections. The inspection, under all sorts of
circumstances, of the wall of cellulose, although it frequently
gave me the impression that it was faintly granulated, and
although delicate filaments emanating from the most peripheral
chlorophyll-granules were often seen tending towards the wall,
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DE. LOUIS ELSBBEG.
did not enable me to arrive at a conclusion concerning its
intimate structure.
Francis Darwin has discovered protoplasmic filaments protruding from the cellulose investment of the glandular hairs
on the leaves of Dipsacus sylvestris ('Quarterly Journal of
Microscopical Science/ 1877, p. 245). Previously, Hoffman
(" Ueber contractile Gefilde bei Blatterschwammen," 'Botan.
Zeitung/1853,p. 857,and 1859,p.214) had described contractile
filaments projecting from cell walls in A m a n i t a (Agaricus)
muscaria, and although De Bary has expressed the opinion
that these are not protoplasmic, Darwin believes them to be
so (' Quart. Journ. Mic. Sc./ Jan., 1878, p. 74). Later, W. J.
Beal (' American Naturalist/ October, 1878, p. 643) described
threads, but does not say that they are protoplasmic, projecting from the end of hairs of several plants. Darwin has
observed filaments of living matter, emanating from the interior of plant cells, pierce the cellulose frame. They protruded from terminal cells only, and of course showed no
interconnection between neighbouring cells. Such interconnection I can now demonstrate.
My first successful observations were made in specimens of
the flowers of flowering flax (Norimbergia gracilis), and of
the leaf and stem of the common india-rubber plant ( F i e u s
elastica), and were obtained as follows. The analogy between
epidermal layers, as well as other parts of a plant, and animal
epithelia, led me to the inference that reagents successfully
applied for elucidating the structure of animal epithelia might
serve for the same purpose in plants. Now, each epithelial
body is a nucleated, reticulated bioplasson mass, enclosed by a
continuous layer of bioplasson and separated from all its
neighbours by a cloak of cement-substance. The cement-substance answers to the cellulose wall of plant cells, and as a
memento of Schleideu and his cell doctrine, I would advocate
not only the retention of the term cellulose, but its extension
to animal tissues, i.e. to take the place of the term cementsubstance. It is known to histologists that the cement-substance is traversed by numerous conical filaments which by
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their discoverer, Max Schullze, were termed " thorns or
prickles." It is also known that upon applying a 2 per cent,
solution of silver nitrate to fresh epithelia, the cement-substance assumes a dark brown hue, and appears perforated by
numerous light transverse lines; while if, on the contrary, a
one half per cent, solution of gold chloride be applied to epithelium, the bioplasson reticulum in its interior assumes a dark
violet tint, the cement substance remains unstained, and in it
Max Schultze's thorns, also coloured deep violet, appear very
plainly. Thus it has been proved that the wall of cementsubstance does not completely isolate the single epithelia, but
is pierced by bridges of living matter which interconnect all
epithelia into one continuous bioplasson mass.
I placed pieces of the flower of " Norimbergia " into a 2 per
cent, solution of silver nitrate for about half an hour, then
washed the specimens with distilled water and exposed them to
daylight. I found that nitrate of silver does not invariably
affect the cellulose alone, but sometimes stains also the "cell w contents; a corresponding general tinction occasionally happens in the case of animal epithelia. Frequently, while the
cellulose wall on the inner surface of the flower was comparatively little coloured by the silver salt and dark granular precipitates filled the spaces between the radiating cellulose offshoots, the polygonal frames on the outer surface of the flower
were beautifully stained dark brown by the silver salt; and
examined with Tolle's immersion lens, showed numerous
interruptions in their continuity, as represented in fig. 2,
exactly like the light-coloured transverse markings seen in
cement-substance of animal epithelia under similar circumstances. Usually the hairs were stained deeply brown; in
many compartments one or several light fields were seen, of
irregular shapes, freely branching; the periphery of such a
light-coloured field often looked serrated, and a reticulum proceeding from it pervaded the whole compartment. This
appearance is shown in fig. 3. In a number of instances I
observed that the septum separating two neighbouring compartments was marked by light-coloured lines, as represented in
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fig. 3.
DE. LOUCS ELSBEBG.
The branching light fields were the smaller the nearer
FIG. 2.—Cells from theflowerof Norimbergia, stained with nitrate of
silver.
FIG. 3.—Hair of flower of Norirabergia, stained with, nitrate of
silver.
the compartment was to the apex of the hair; at the end, the
whole hair, as a rule, appeared uniformly dark brown, or contained in its interior an extremely delicate, light-coloured
reticulum only.
After a one half per cent, solution of gold chloride had been
brought to bear upon pieces of the flower for about forty
minutes, the wall of cellulose became more distinct although
not coloured by the gold salt. In the interior of the polygonal
fields, on the inner surface, a scalloped body had made its
appearance; it was slightly retracted from the cellulose frame
and offshoots, bordered by a continuous delicate layer, and
filled with a very distinct reticulum in connection with a
central coarsely granular and also reticulated nucleus. The
bordering layer and the reticulum around the nucleus, as well
as the nuclear wall and the intranuclear granules and reticulum, were of a dark violet colour, just as in animal epithelia
PLANT CELLS AND LTVING MATTER.
(see fig. 4).
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On the outer surface the epidermal bodies
FIG. 4.—Cells from flower of Norimbergia, stained with gold
chloride.
exhibited a distinctly reticular structure. The hairs showed
dark violet granules and clusters of granules in the interior of
the compartments; these granules had radiating offshoots
which formed a network, with frequently distinctly granular
thickened points of intersection, as represented in fig. 5.
There could be no doubt that this was the positive image of
the structure that was demonstrated by the silver staining in a
negative manner as depicted in fig. 3. In some, especially in
small hairs, the dark violet reticulum in the compartment was
very dense. Frequently, delicate violet filaments pierced the
transverse septa of neighbouring compartments and interconnected the reticula and bioplasson formations in their interiors,
as seen in fig. 5.
But the most complete proof of the existence of living matter
within the cellulose walls of plant " cells" I obtained in
sections of the stems of leaves of the common india-rubber
plant (Ficus elastic a), a silver-stained specimen of which
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DB, LOUIS ELSBEEG.
is represented in fig. 6. The latex oozing out of the stem
proved to be composed of a viscid, as if mucous, colour-
PIG. 5.—Hair of flower of Norimbergia, stained with gold chloride.
less liquid, in which were suspended innumerable isolated
granules of a high lustre, somewhat similar to that of fat;
gold chloride staining made the smallest granules appear dark
violet, while the larger were only indistinctly coloured, retaining their high lustre. Transverse sections of the stem,
examined in dilute glycerine, showed chlorophyll-granules and
the reticular structure. The parenchyma of some specimens,
especially those treated with strong alcohol, plainly exhibited
the layer of living matter in the interior of the " cell," which
Von Mohl called " Primordial utricle/'and sacs, more correctly
" protoplasmic sac;" and in many cases the bioplasson mass
showed the reticular structure. Treatment of gold chloride
not only rendered the network of many bioplasson bodies
distinctly visible, but in some cases offshoots emanating
""from such bodies were seen to penetrate more or less far into
the cellulose investment; what has been sometimes de-
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PLANT CELLS AND LIVING MATTER.
scribed by author's, especially in growing tissues, as " intercellular spores " and " middle lamellae/' in the cellulose were
*•
,.
FIG. 6.—Cells from petiole of Ficus elastica, treated with silver nitrate.
revealed to be in a number of instances accumulations and filaments of living matter wedged in between the " plant cells,"
very much like the wedges of bioplasson and the medullary
elements which I have found to grow between animal epithelia in cases of new growths ("Microscopical Study of
Papilloma of the Larynx/' ' Archives of Laryngology/ March,
1880). Treatment with the solution of silver nitrate revealed
in the darkened substance of the cellulose light spaces occupying the position of such wedges. These light spaces sent
off comparatively broad offshoots parallel to the inner surfaces
of the cellulose frame, and innumerable delicate light offshoots from both the central space and the broad offshoots
traversed the brown cellulose in uninterrupted connection with the delicate light reticulum seen here and there
within the so-called " plant cell." The appearance of the
silver-stained cellulose frame in a portion of such a specimen
is accurately reproduced in fig. 6, and the results obtained in
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NEW SISR.
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DR. LOtJIS ELSBERG.
these specimens I have verified by very numerous other examinations.
My researches demonstrate, and so far as I know, demonstrate for the first time, that the frame of cellulose, analogously
to the cement substance of animal 'epithelia and the basis
substance of other animal tissues, is pierced by either single
filaments of living matter or a reticulum with more or less
large accumulations .of living matter, interconnecting all
neighbouring tissue elements, and that the plant, therefore,
like the animal, is one continuous mass of living matter, with
interspaces which contain some non-living material.
The structure of plant tissue may be illustrated by the
structure of hyaline cartilage of animals. For many years it
was believed that cartilage consists of a homogeneous nonliving basis substance in which are embedded, at various
distances a)>art, isolated living cartilage corpuscles—cavtilage" c e l l s " as they were called. TRe more or less convincing
observations made by Heitzmann, and after him by Hertvyig,
Thin, Prudden, Spina, and Flesch, have shown this to be a
mistake; and the results which I obtained in the histological
examination of the cartilages of the larynx (published in the
'Archives of Laryngology/ October, 1881, and January, 1882),
have proved beyond question that hyaline cartilage is a filigree
of living matter, in the meshes of which lumps of basis
substance are embedded. According to the former view cartilage could be compared to a pudding, in the dough of which
a certain number of^raisins are embedded ; in truth, it is like
a framework composed of larger and smaller raisins and bands
and strings of raisin substance, in the meshes or interspaces
of which blocks of dough are embedded.
Just so in the tissue of plants, the so-called plant " cells"
are connected one with the other, and blocks of cellulose fill
up the interstices in the network of living matter.
Not to trespass too much upon the patience of the reader, I
must leave undetailed here the far-reaching consequences of
the " bioplasson doctrine " for the better understanding of the
relations and phenomena of plant life.