BIOLOGY
UBRARY
G
INVESTIGATIONS
ON MICROSCOPIC FOAMS
AND
ON PEOTOPLASM
INVESTIGATIONS
ON
MICROSCOPIC FOAMS
AND ON
PKOTOPLASM-
EXPERIMENTS & OBSERVATIONS DIRECTED TOWARDS A SOLUTION
OF THE QUESTION OF THE PHYSICAL CONDITIONS
OF THE PHENOMENA OF LIFE
BY
0. BUTSCHLI
H
PROFESSOR OF ZOOLOGY IN THE UNIVERSITY OF HEIDELBERG
AUTHORISED TRANSLATION
BY E. A. MINCHIN, B.A. (OxoN.)
FELLOW OF MERTON COLLEGE, OXFORD
LONDON
ADAM AND CHAELES BLACK
1894
BIOLOGY
LIBRARY
G
TRANSLATORS PREFACE
IN bringing an English translation of this work before the
public, I feel that a word or two of explanation is due to
my readers. Many people regard the translation of French
or German scientific works as unnecessary, holding that
every student of science should have a knowledge of these
languages. Without wishing to controvert this opinion
generally, I may state the reasons which originally prompted
me to undertake this translation. In the first place,
the investigations here described are of so fundamental a
nature as to be of interest not only to workers in all the
various branches of Biology, and to physicists, but perhaps
even to those who are not professed students of science at
all. In the second place, this work, lying as it does for the
most part on the border-line between two sciences so
distinct as Physics and Biology, is full of the technicalities
of both these sciences, and is therefore by no means easy
reading in the original for a modern scientific specialist,
however great his knowledge of the German language.
For these reasons it seemed to me that a translation of
Professor Blitschli's valuable investigations might form an
acceptable addition to English scientific literature.
In preparing this translation certain German words
and phrases were found especially difficult to render into
English. Above all, this was the case with the two words
vi PROTOPLASM
" Entmischung " and " Ausbreitung," applied to the peculiar
physical phenomena described fully on p. 15 and p. 62 et
seq. respectively. Not being able to find English equiva-
lents for these words I applied to Lord Eayleigh, Sec. R S.,
for advice, and with his kind help I have coined the word
desolution for "Entmischung," while "Ausbreitung" I have
rendered at his suggestion by the word extension or super-
ficial extension. There is no need for me to explain these
terms here, as that is done in the text at the places
indicated.
Protoplasm is conceived of in this work as having the
structure of a froth or foam in which minute droplets of a
watery liquid take the place of air in the bubbles of an
ordinary foam. Such a structure is termed by the author
" Wabenstructur," i.e. honeycomb structure ; the separate
vesicles, bubbles, or droplets of the foam are termed
" Waben," i.e. cells of a honeycomb. The latter word has
been rendered throughout by the term alveolus, and the
structure is generally termed alveolar. The most super-
ficial layer of radially directed alveoli, which gives the ap-
pearance of a striated border, has been termed by the
author the "alveolar layer" ("Alveolarschicht") par excellence.
In order to avoid confusion this has been rendered in many
places marginal alveolar layer, in other places simply
alveolar layer.
The plan has been followed of printing the book in two
types, in order that the student may be able to obtain first
of all a general idea of its contents, without entering into
details, by reading the portions printed in the larger type
consecutively.
Finally, it is my pleasant duty to express my thanks
for the assistance I have received in preparing this transla-
tion. Without Professor Eay Lankester's kind help the
work would never have been undertaken. To the Author
TRANSLATOR'S PREFACE vii
and to my friend Mr. Hatchett Jackson I am greatly
indebted for the trouble they have taken in looking over
the proofs, and for making many valuable suggestions and
corrections. My obligations to Lord Eayleigh have already
been stated.
E. A. M.
OXFORD, January 1894.
CONTENTS
PAGE
INTRODUCTION . . 1
PAET I
OBSERVATIONS ........ 5
A. Investigations upon Oil-Foams ..... 5
1. Preparation and Structure of the Foams ... 5
2. Some more exact Statements as to the Alterations in
Volume of the Drops of Foam under the Influence
of the surrounding Fluid . . . .38
3. Radiate Appearances in the Drops of Oil-Foam . . 41
4. Fibrous Structures in Drops of Oil-Foam . . .44
5. The Durability of the Oil-Foams . . . .46
6. The Phenomena of Streaming Movement exhibited by the
Oil-Foams ...... 47
7. The probable Explanation of the Streaming Movements
exhibited by the Drops of Foam . . .61
8. Streaming Movements exhibited by Drops of Foam in Cells 80
9. Remarks upon Frommann's Experiments on Drops of Oil-
Foam. ...... 82
B. Investigations upon Protoplasmic Structures . .85
1. Investigations upon Protozoa . . . .86
Suctoria ....... 87
Ciliata ....... 88
Flagellata . . . . . . .91
Radiolaria ....... 92
Heliozoa ....... 93
Marine Rhizopoda with Calcareous Shells and Reticulate
Pseudopodia ...... 94
Gromia Dujardini, M. Schultze . . . .101
Amrebse .... 106
PROTOPLASM
PAGE
JEthalium septicum (Fuligo varians) . . .111
Pelomyxa palustris, Greeff . . . .116
2. Ou Protoplasmic Structures in the Bacteria and allied
Organisms ...... 117
3. Some Observations on the Streaming Protoplasm of Vege-
table Cells ...... 122
4. Observations on some Egg Cells . . . .124
5. Red Blood Corpuscles of Rana esculenta . . .127
6. Observations on some Epithelial Cells . . .131
7. Peritoneal Cells on the Gut of Branchiobdella astaci, etc. . 136
8. Liver Cells of Rana esculenta and Lepus cuniculus . 140
9. Epithelium of the small Intestine of Lepus cuniculus . 142
10. Pigment Cells of the Parenchyma of Aulastomum gulo . 143
11. Capillaries from the Spinal Marrow of the Calf . . 143
12. Connective Tissue Cells between the Nerve Fibres of the
Ischiadic Nerve of Rana esculenta . . . 144
13. Ganglion Cells and Nerve Fibres . . . .145
PART II
GENERAL PART ........ 157
A. The Theory of the Net-like or Reticular Structure of Proto-
plasm ...... 159
B. Summary of Divergent Views ..... 177
1. The Theory of the Fibrillar Structure of Protoplasm . 177
2. The so-called Spherular Theory of Kiinstler . .184
3. The so-called Granular Theory of Protoplasm . . 191
4. Attempts to explain the Reticular Structures as Pheno-
mena of Coagulation or Precipitation . . 201
The Nature of Colloid Bodies . . .216
5. The Structure of Protoplasm is Alveolar or Honeycombed
(Foam-like) . . 219
(a) Aggregate Condition of Protoplasm . . . 220
(6) Vacuoles ....... 227
(c) External Surface of the Protoplasm . 234
(d) Alveolar Layer . .236
(e) Cell Membranes, Cuticulse . . . .240
(/) Radiate Layer of Alveoli round the Nucleus . . 243
(g] Granular Enclosures in Protoplasm, and Corresponding
Position of Soot Particles in the Artificial Foams . 244
(h) Radiate Appearances in Protoplasm during Cell Division 246
(i) Radiate Appearances in Ova, etc. . . 251
(/) Striated Protoplasm of Epithelial Cells . . .254
CONTENTS xi
PAGE
(&) Fibrous Protoplasm ..... 255
(I) Theories concerning the Causes of Radiate Appearances . 257
6. The Homogeneous Protoplasm and the Alveolar Theory . 262
7. The Phenomena of Protoplasmic Movement in their
Relation to the Alveolar Structure . . .267
(a) Theories as to the Causes of the Phenomena of Movement 267
(6) So-called Contractility . . . . .267
(c) Contractility of the alleged Reticular Framework . 269
(d) Objections to the Theory of Contractility . . 270
(e) Hypotheses of Hofmeister, Sachs, and Engelmann . 271
(/) Electrical Hypotheses of Velten and Fol . . . 279
(g] Leydig's View of the so-called Hyaloplasm . . 280
(h) Montgomery's Hypothesis .... 287
(i) Hypotheses relating to Surface Tension Berthold,
Quincke . . . . . .289
(/) My own View of the Explanation of Amreboid Move-
ment . . . . . .307
On the Currents in the Water surrounding Amoebae,
etc. . . . . . . .317
(&) Independent Movements of Granules . . . 319
(I) Causes of Internal Displacements in the Alveolar Proto-
plasm ...... 323
(m) Possibility of an Explanation of Muscular Contraction in
this Way ...... 325
(n) Rotational Currents in Plant Cells . . .327
LITERATURE ........ 331
EXPLANATION OF THE PLATES ...... 341
INDEX . 367
LIST OF ILLUSTRATIONS
PRINTED IN THE TEXT
FIG. PAGE
1. Formation of foam in an oil-drop placed in water. The darker peri-
pheral zone represents the portion which has become frothy, while
the centre of the drop is occupied by clear homogeneous oil. IXaCl,
fragments of common salt ; v, vacuoles . . . .12
2. Diagram of the union of three lamellse of a foam in one edge, as seen
in optical section . . . . . . .27
3. Diagram representing an optical section of the superficial region of a
foam. The arrows a, b, c, represent the tensions of three lamellae
at the surface . . . . . . .33
4. Diagrammatic optical section of the greatly attenuated margin of a
drop of oil-foam . . . . . . .37
5. Diagram showing the course of the currents in a drop of oil-foam
placed in dilute glycerine. 0, the upper, a, the lower side of the
drop ; 0, slide ; D, cover glass . . . . .48
6. Outline sketch showing one of the forms assumed by a large drop of
oil-foam in active movement. The pairs of dotted arrows repre-
sent centres of extension-currents . . . . .51
7. Outline sketches showing the forms assumed by a drop of oil-foam,
when warmed and moving actively, during a period of ten minutes.
Arrows to denote extension-currents . . . .53
8. Outline sketches of a drop of oil-foam under the influence of the
electric currents ; taken at intervals of five minutes, to show the
changes of form and movement consequent upon change of the
poles. The signs + and - denote the positive and negative poles ;
the arrows denote the extension-currents . . . .58
9. Diagram showing the system of extension-currents produced in a
drop of oil placed in water under the cover glass, when approached
on one side by soap solution. The arrows denote the currents.
m, the axial quiescent streak ; #, the posterior quiescent region . 62
10. Diagram showing extension-currents in a drop of paraffin oil under
similar circumstances, and also the currents in the surrounding
water 64
xiv PROTOPLASM
FIG. PAGE
11. Diagram of a drop of oil containing particles of lamp-black in sus-
pension, showing the position assumed by the lamp-black under
the action of extension-currents . . . . .69
12. Diagram showing the extension-currents produced in a drop of oil
when approached by a bent platinum wire, heated by means of an
electric current . . . . . . .72
13. Diagram showing the extension-currents produced in a drop of oil
in contact with a capillary tube containing soap solution . . 73
14. Diagram showing a method of obtaining circulatory extension-
currents in a drop of paraffin oil . . . .74
15. The same as Fig. 5 . . . . . . .76
16. Diagram of a section through a drop of oil under the cover-slip when
free from pressure (A) and when compressed (B) . . .78
17. Sketch of two streaming drops of oil-foam in closed cells . .80
18. Diagram representing the true reticulum (a) with an exact focus,
and the false optical reticulum (b) with a higher focus . .215
19. Diagram of the currents set up in a drop of water on a slide, when
approached by ether on one side. To show the currents ivory
black has been mixed with the water .... 301
20. Diagram of a median longitudinal section through the drop shown
in Fig. 19 . . . . . . . .302
21. Diagram to show the currents in the growing pseudopodium of an
Amoeba ........ 311
22. Diagram of muscle contraction ..... 325
23. Diagram of rotational streaming in plant cells . . . 328
LIST OF PLATES
PLACED AT THE END OF THE VOLUME
I. Illustrations of the minute structure of the protoplasm and the pseudo-
podia of Gromia Dujardini M. Schultze.
II. The minute structure of the protoplasm and pseudopodia of Foramini-
fera (Figs. 1-6) and Anuzbce (Figs. 7 and 8).
III. Illustrations of the pseudopodia of Foraminifera (Figs. 1-4) and the
body protoplasm of Acineta (Fig. 5).
IV. Illustrations of the minute structure of Foraminifera (Figs. 1 and 2),
Amcebcc (Figs. 3 and 4), and Ciliata (Figs. 5-8), and of vegetable
protoplasm (Fig. 9).
V. Illustrations of the minute structure of the ova of a sea-urchin, Sphcer-
echinus (Fig. 1, a-c), of the protoplasm of Thalassicolla (Fig. 2, a
and b) and Chilomonas (Fig. 3), and of oil-foams (Figs. 4 and 5).
VI. The minute structure of oil-foams (Figs. 1 and 2) and of an epidermic
cell of Lumbricus (Fig. 3), a fat cell of Blatta (Fig. 4), and the epi-
dermis of Gammarus.
VII. The protoplasm of various tissue cells ; liver cells of the frog (Fig. 1) ;
peritoneal cell (Fig. 2), epidermis and cuticle (Fig. 3, a-c) of
Branchiobdella ; egg (Fig. 4) and ciliated cells (Fig. 5) of Hydatina;
pigment cell of Aulastomum (Fig. 6), and nerve fibre of Astacus
(Fig. 7).
VIII. The minute structure of the protoplasm of ganglion cells and axis-
cylinders from the frog (Fig. 1), calf (Fig. 2), and earthworm (Fig.
3) ; and of connective tissue cells from the frog (Fig. 4).
IX. The minute structure of capillaries, ganglion cells, and axis-cylinders ;
a capillary (Fig. 1), a process of a ganglion cell (Fig. 2), and an axis-
cylinder (Fig. 3) from the calf, and transverse sections of axis-cylin-
ders from the frog (Fig. 4, a-c).
xvi PROTOPLASM
PLATE
X. Blood corpuscles of the frog (Fig. 1, a and 6) ; axis-cylinder, in trans-
verse section, of the rabbit (Fig. 2) ; pseudopodium of Actinosplimrium
(Fig. 3) ; structure of a thin lamella of oil-foam (Fig. 4) ; and draw-
ings to show the optical network, produced by intersection of dif-
fraction rings, between minute suspended droplets of oil (Fig. 5,
a-c).
XI. A thin section through the cuticle and hooks of Distomum.
XII. Pseudopodium of Actinosphcerium (Fig. 1) ; protoplasmic filament from
a cell of Tradcscantia (Fig. 2) ; section through cells of the intestinal
epithelium ofDistomum (Fig. 3) ; stalk muscle of Zoothamnium (Fig.
4) ; and tentacle of Acineta in optical section (Fig. 5). For Fig. 6
compare the text, p. 179.
INTRODUCTION
IN the preface to the studies published by me in 1876,
upon the primary developmental processes of the ovum, cell
division, etc., I pointed out that the morphological method
of consideration, which had led to such brilliant results for
the comprehension of multicellular organisms, fails to be of
service to us when we attempt to penetrate deeper into
the essential nature of the elementary organism the cell.
I expressed the view " that the phenomena exhibited by and
in the elementary organism could not assume an intelligible
form except through a knowledge of the physical and
chemical conditions of their origin and cessation." I also
attempted in this work, and, as I believe, for the first time,
to bring into requisition a property of fluid bodies, -namely,
surface tension, in order to explain the phenomena of the
division of the protoplasmic cell body, of which I had made
a careful study.
In the following investigations I believe I am able
to bring forward a contribution towards a more accurate
physical explanation of certain peculiarities of living matter
or protoplasm. Since it is far from my intention to enter
at present into detailed historical disquisitions upon the
question of the structure and nature of protoplasm, I will
only put forward here a few historical remarks upon my
own position with regard to this question, in order to indi-
cate the train of reasoning which led to the investigations.
In 18*78 I found an opportunity for the first time
of expressing my opinion upon the alleged reticular struc-
ture of protoplasm, which had come more to the fore at
l
2 PROTOPLASM
this time through the works of Frommann, Kupffer, Heitz-
niann, and others. I remarked at that time that the facts
which had become known concerning this point " do not,
however, seem to me by any means so noteworthy and so
unconnected with former observations as was usually repre-
sented. From the protoplasm of many Protozoa in which
appear single scattered vacuoles there is a gradual transi-
tion to be found to completely alveolar or, what is the
same thing, reticular protoplasm, where the alveoli are so
densely crowded that their real protoplasmic walls take on
a honeycombed arrangement, which in optical section appears
reticular." I further remarked that in the hyaline cortical
layer and the pseudopodia of Ehizopods, we had before us
structureless homogeneous protoplasm. Thus, as far back as
1878, I represented the view that the reticular structure of
protoplasm described by various investigators was a honey-
combed or alveolar structure.
My extensive dealings with Protozoa of very various
groups, to which I had to devote myself during the follow-
ing years, gave me the opportunity for many an observation
upon protoplasmic structures, which more and more con-
firmed me in the view I had already expressed in 1878.
In the years 1884 and 18851 was first able to study more
thoroughly relations of this kind in 1884 Noctiluca ; in
1885, a series of marine Bliizopods, Adinospliccrium, and
certain Ciliata. More definitely than before I expressed
my conviction that the so-called reticular structures should
be interpreted as honeycombed, and founded this conception
upon the proof of the indubitable honeycomb structure of
the so-called " alveolar layer." I also brought forward
proofs of the reality of the protoplasmic structures, the
resemblance of which to the products of the coagulation
and precipitation of various substances might awaken a per-
fectly justifiable suspicion as to whether they did not also
belong to the same category of phenomena. I soon found
occasion for engaging still more thoroughly in studies of this
kind, when in the years 1886-88 I undertook to do the
Ciliata for Bronn's Klassen und Ordnungen. In my own
studies upon this group I was able to avail myself of the
INTRODUCTION 3
assistance of two talented pupils, Dr. Schuberg and Dr.
Schewiakoff. In their works upon Ciliata (1886 and 1889),
which were carried on in continued collaboration with me,
they have brought forward in support of my conception,
essential contributions from within the limits of this group
of Protozoa. On the ground of their investigations, as well
as of others of my own, I was able in my description of
the Infusoria to give a somewhat broader and more detailed
exposition of my view (pp. 1317, 1392). The experience
gained up to this point had called forth the conviction that a
phenomenon of fundamental importance was before us ; a
conviction which I expressed at that time (18 8 8) in the
following words : " We are here confronted with a pheno-
menon of the same widespread occurrence and significance
as the building up of higher organisms from cells, without
possessing at the outset a guiding and explanatory idea, just
as was the case with the observers of cellular tissue before
the cell theory had been founded." Although convinced that
the structure of protoplasm was in general alveolar, I yet
thought it necessary at that time (p. 1392) to make a con-
cession to the theory of its spongy structure, inasmuch as I
admitted " that at times adjacent alveoli may break through
into one another, and thus a spongy structure would come
to be formed in places." This remark was particularly
inconsistent in the case of the endoplasm, since I at the
same time represented its nature as fluid, and such an
assumption excludes any idea of the kind.
As a proof, to a certain extent, of the significance which
the theory of the honeycomb structure of protoplasm
might possess for the conception of protoplasm as a whole,
I also described in 1888 the consequences which result
from it for the growth of protoplasm, by trying to show that
the difficulty in conceiving of growth by intussusception
could be got over upon the basis of my theory.
As is obvious from this proposition and from the view
quoted above from my work on Protozoa, I cherished the
idea, ever since the universal occurrence of such struc-
tures in protoplasm became clear to me, that in this
fact an essential reason was to be sought for many of the
4 PROTOPLASM
peculiar properties and activities of this substance. Accord-
ing to my conception the structure of protoplasm corre-
sponded to that of the minutest microscopic foams, with the
difference that the alveoli of ordinary foams contain air,
while protoplasmic foams contain a watery fluid. If such
microscopic foams were successfully manufactured, ought
they not to show certain peculiarities of protoplasm, and
could not an accurate study of them furnish an essential
contribution towards confirming or correcting my view ?
This question forced itself upon me more and more strongly.
Whether the results obtained in this direction might or
might not be favourable to my view, it was to be hoped in
any case that they would contribute to the clearing up of
the protoplasm question.
PAKT I
OBSERVATIONS
A. Investigations upon Oil-Foams
1. Preparation and Structure of the Foams
THE reflections and considerations set forth in the preceding
pages impelled me to try if it were possible to produce
artificial foams of the fineness that I believed to exist in
the instance of protoplasm. Although it was scarcely to be
expected that such attempts would produce results at all
considerable, I thought nevertheless that something or other
of importance might possibly be attained by such a course.
Hence I sought to follow it up, as soon as time and
opportunity offered, on the completion of my work upon
Protozoa. Experiments of this kind could at first be little
better than a blind groping about, as it were, in the hope
of finding a possible starting-point from which advance
might be made in a more methodical and confident manner.
I began this attempt with a feeling of vague uncertainty,
such as the alchemists must have felt in their hopeless
experiments. This uncertainty was, as may be easily con-
ceived, heightened by the fact that I was setting foot in a
region in which I was very little at home, and the difficulties
of which were hence far beyond my ken. Still this
ignorance proved perhaps, if anything, serviceable ; with a
sufficient appreciation of the difficult problems of molecular
6 PROTOPLASM
physics in which I set myself to dabble, the experiments
would perhaps _have never been undertaken.
Various fruitless attempts were made first with different
kinds of emulsions, which led to no satisfactory results, since
they were not to be deprived of the character of an emulsion,
i.e. of minute drops suspended in a relatively abundant fluid
matrix. A foam of fine structure was, however, for the
first time successfully produced by the mixing of two fluids.
Without describing here the previous experiments that gave
no result, I will proceed to make a few remarks on the
attempts that were first successful. If a very thick solution
of commercial soft soap (potash soap) be shaken up thoroughly
with benzin or xylol, a fine emulsion is formed, since the
benzin distributes itself in the soap solution in drops
varying in size from those of moderate fineness to the very
minutest. If this emulsion be then left to stand, the lighter
benzin droplets rise to the surface, and become arranged,
through the thinning out of the layers of soap solution
between them, into a fine froth, just as bubbles of air rising
to the top of a soap solution collect gradually on its surface
into an ordinary lather. The description and explanation
given by Plateau for the latter case is without doubt also
suitable for the froth here described. The whitish foam,
in which benzin plays the part of air in an ordinary
soap lather, attains to a considerable degree of fineness, but
is not to be compared in this respect with the froths which
I obtained later in another way. I have not taken any
measurement of the average size of its meshes, since such
benzin foams are difficult to investigate, but they stand
somewhere on the boundary between the macroscopic and
the microscopic, since at least their larger meshes are visible
with the naked eye or with a weak lens. Nevertheless the
durability of froths of this kind is striking. I have kept
such a froth for two years now in a tightly-stoppered bottle