the arguments on the other side. It is always assumed that the
reactions of an organ, or part of the organism, when separated from
the rest, are typical of their reactions when forming constituents
of the normal organism. Nothing of the kind. The movement of a
muscle or a limb separated from the body may resemble that movement
when normally effected--but only as the movements of a mechanical
bird resemble those of a living bird: the modes of production are
different. So that were we to grant the postulate of the brain
being the exclusive seat of sensation, we should still deny that an
action which was effected after removal of the brain was typical of
the action effected when the brain was present. The leg of Hunter’s
patient jerked when the skin was irritated; but this action could not
be altogether the same as the similar action in a leg united with the
rest of the sensitive mechanism. Nor is this all. The leg may have
been insensible, the spinal segment which innervated it may have been
wholly without Sensibility, and still we should have to question the
logic which extended such an inference to the very different and far
more complex actions of decapitated animals. On this ground:--The
leg is, by the hypothesis, insensible because cut off from all
connection with the sensitive mechanism. But this is not the case
with the decapitated animal: there still remain the essential parts
of a sensitive mechanism--all the chief organs are still in activity,
still manifesting their functions. Decapitation has produced a great
disturbance in the mechanism, and has removed an important centre; but
nevertheless every impression excites a connected group of centres, and
this group responds.
* * * * *
94. In conclusion, unless we adopt the opinion that
Sensation--Consciousness--Sensibility, is something not belonging to
the physiological properties of the nervous system in a vital organism
(the opinion held by spiritualists), there seems no alternative but
to adopt the opinion advocated in this volume, namely, that the
physiological properties of the nervous system are inseparable from
every segment of that system; and the functions are the manifestation
of those properties as determined by the special organs with the
co-operation of all.
FOOTNOTES
[1] WORDSWORTH.
[2] Crystals not only grow by assimilation, but even repair injuries,
with a certain superficial resemblance to the repair of animal tissues.
Thus, according to the experiments of JORDAN cited by Sir JAMES PAGET
(_Lectures on Surgical Pathology_, I. 153, and 2d ed. p. 115), an
octohedral crystal of alum, if fractured and replaced in a motherlye
will in a few days exhibit a complete restoration of the original form.
The whole crystal increases, but the increase is greatest on the broken
edge, and the octohedral form is completely renewed. (Comp. § 113.)
[3] Cited by DRYSDALE, _Life and the Equivalence of Force_, Part II. p.
149.
[4] RANKE, _Die Lebensbedingungen der Nerven_, 1868, p. 80.
[5] “Il n’y a peut être pas un seul phénomène chimique dans l’organisme
qui se fasse par les procédés de la chimie de laboratoire; en
particulier il n’y a peut être pas une oxydation qui s’accomplisse par
fixation directe d’oxygène.”--CLAUDE BERNARD.
[6] Dr. MADDEN, in his essay _On the Relation of Therapeutics to
Medicine_, 1871, p. 5, gives a remarkable illustration of what may be
called the frustration of chemical affinity effected by mechanical
conditions. “Before calico can be printed, every loose particle of
cotton must be removed from the surface in order that the colored inks
may not run. This removal is effected by passing the calico over and in
contact with a red-hot iron cylinder, and by regulating the rapidity
with which the cylinder revolves, the intense heat burns off the loose
fibres, yet does no injury to the woven cloth. In other words, the
changes in the relation of the high temperature and the cotton are
too rapid to admit of the fibre combining with the oxygen. Let the
rate of revolution be reduced but very little, and the calico would
burst into flames.” Any one who has snuffed a candle with his fingers
will understand this. Dr. Madden further instances certain fulminates
which can be detonated in contact with gun-cotton without causing it
to explode--the extreme rapidity with which the fulminates expand is
too great to enable the gun-cotton to adjust its movements to this new
motion. Precisely the same kind of thing occurs in organized matter. If
the rate of its changes be reduced below a certain point, the ordinary
chemical affinities will assert themselves.
[7] I am often reminded of the surprising movements of particles of
carbonate of lime in water which my friend Professor PREYER showed
me during a visit to Bonn. He had removed one of the concretions,
usually found in connection with nerves along the spine of old frogs,
and crushed it in water; under the microscope the seeming spontaneity
and variety of the movements of the particles was such that had we
not known their origin we should certainly have attributed them to
vitality: no infusoria could have moved with more seeming spontaneity.
It is hardly physiological to conclude that because fragments of tissue
manifest ambœbiform movements therefore they are alive (STRICKER,
art. _Die Zelle_ in his _Handbuch der Lehre von den Geweben_, 1868,
p. 7), or that the heart removed from the body is _alive_ because it
still beats. LIEBERKÜHN, _Ueber Bewegungserschsinungen der Zellen_,
1870, pp. 357–359, cites examples of such movements in undeniably dead
substances. For Life, we demand not only Movement, but Functional
Activity.
[8] TELESIUS, _De Natura Rerum_, 1586, V. 184. TELESIO might have been
saved from the mistake had he attended to what NIPHUS had said on
the point in his _Expositio subtilissima_, 1559, p. 245. Comp. also
PHILELPHUS, _Epist. Familiarum_, 1502, p. 253, _verso_.
[9] The authorities just cited are ARISTOTLE, _De Anima_, Lib.
II. c. I. KANT, _Kritik der Urtheilskraft_. MÜLLER, _Physiology_.
BEALE, _Bioplasm_, and _Introduction to Todd and Bowman’s Anatomy_.
SCHELLING, _Erster Entwurf_, and _Transcendent. Idealismus_. BICHAT,
_Recherches sur la Vie et la Mort_. STAHL, _Theoria Vera Medica_.
DUGÈS, _Physiologie Comparée_. BÉCLARD, _Anatomie Générale_. LAMARCK,
_Philosophie Zoologique_. COMTE, _Cours de Philosophie Positive_.
OWEN’S _Hunterian Lectures_, 1854. HERBERT SPENCER, _Principles of
Biology_.
[10] FLETCHER, as quoted by DRYSDALE, _Life and the Equivalence of
Force_, Part II. p. 120.
[11] ROBIN et VERDEIL, _Traité de Chimie Anatomique_, 1853.
[12] PAGET, _Lectures on Surgical Pathology_, p. 14.
[13] Comp. HAECKEL, in _Siebold und Kölliker’s Zeitschrift_, 1865, p.
342, and his _Generelle Morphologie_, 1866, I, 135, 336.
[14] In the _Archiv für mikros. Anatomie_, 1865, p. 211.
[15] Here organization is the simplest form of all--molecular organized
structure, which in the higher forms becomes tissue structure,
and organ structure. The word _structure_ properly means orderly
arrangement of different materials; and molecular structure refers
to the different proximate principles which constitute the organized
substance. Usually, however, the word _structureless_ indicates the
absence of _visible_ arrangement of the parts; a cell has structure
since it has nucleus and protoplasm.
[16] In the cell-theory established by SCHLEIDEN and SCHWANN, in 1838,
and which has formed the basis of modern histology, the cell-wall
was endowed with an importance which can no longer be upheld now
that the existence of independent organisms, and of cells, without
a trace of enveloping membrane has been abundantly observed. Cells
without walls were first described by COSTE in the _Comptes Rendus_,
1845, p. 1372. They were also described by CHARLES ROBIN in 1855,
_Dict. de la Médicine_, art. _Cellule_. But little notice was taken
until MAX SCHULTZE, in his famous essay, _Ueber Muskelkörperchen
und was man eine Zelle zu nennen habe_, which appeared in _Reichert
und Du Bois Reymond’s Archiv_, 1861,--BRUECKE, in his memoir, _Die
Elementarorganismen_, 1861,--and LIONEL BEALE, in his _Structure of the
Simple Tissues_, 1861,--all about the same time began the reform in
the cell-theory which has effected a decisive change in the classical
teaching. LEYDIG claims, and with justice, to have furnished important
data in this direction (_Vom Bau des thierischen_ _Körpers_, 1864, I.
p. 11). The student interested in this discussion should consult MAX
SCHULTZE, _Das Protoplasma der Rhizopoden und der Pflanzenzellen_,
1863; HAECKEL, _Die Radiolarien_, 1862; the controversial papers by
REICHERT, in his _Archiv_ (beginning with the Report of 1863), and MAX
SCHULTZE, in his _Archiv für mikros. Anat._, with HENLE’S judgment in
his _Jahresberichte_, and KÜLLIKER’S summing-up in the last edition of
his _Gewebelehre_. For a full yet brief history of the cell-theory see
DRYSDALE, _The Protoplasmic Theory of Life_, 1874, pp. 96–106.
[17] At the time this was written, I had some fish ova in the course
of development. Out of the same mass, and in the same vessel, all
those which were supported by weed at a depth of half an inch from
the surface, lived and developed; all those, without exception, that
were at a depth of two to four inches, perished. In ordinary parlance,
surely, nothing would be objected to in the phrase, “these ova were
all in the _same_ Medium”; the water was the same, the weed the same,
the vessel the same; yet some difference of temperature and carbonic
acid made all the difference between life and death. Another curious
fact was observed; I removed eight of these ova with active embryos,
and placed them in a large watch-glass containing a solution (one half
per cent) of bichromate of ammonia. In this acid the embryos lived
and were active fifty-seven hours, although other embryos placed in a
similar watch-glass containing pond-water, survived only forty hours.
The non-effect of the acid was probably due to the non-absorption
which nullifies the effect of certain virulent poisons when they are
swallowed; but why the fish should live longer in the acid than in the
simple water, I do not at all comprehend.
[18] AGASSIZ, _Essay on Classification_, 1859, p. 15.
[19] HAECKEL, _Generelle Morphologie_, II. 211.
[20] See on this last point RANKE, _Die Lebensbedingungen der Nerven_,
1868, p. 34.
[21] See WALDEYER, art. _Eierstock_, in STRICKER’S _Handbuch der Lehre
von den Geweben_, 1870, p. 570. “I found in a fœtus, which, in a case
of extra-uterine pregnancy, had lain thirty years in the body of its
mother, the structure of the muscles as intact as if it had been born
at its full time.”--VIRCHOW, _Cellular Pathologie_, Lect. XIV.
[22] See BEALE, _The Structure of the Simple Tissues_, 1861; the
Introd. to his edition of _Todd and Bowman’s Physiological Anatomy_,
1866; and _How to Work with the Microscope_, 4th ed., 1868; also
_Bioplasm_, 1872.
[23] “The physical property of the tissue does not depend upon this
matter, _nor is its function due to it_.”--Beale, _Introduction to Todd
and Bowman_, p. 11. That is to say, he regards even contractility and
neurility as physical, not vital facts.
[24] In turning over the pages of a work which was celebrated some
half-century ago--RUDOLPHI’S _Grundriss der Physiologie_--I was
interested to find a clear recognition of this biological principle:
“Alle Theile aller Organismen,” he says, I. 233, “sie mögen noch so
verschieden in ihrem Bau, in ihrer Mischung, und in ihrer Thätigkeit
seyn, sind ohne Ausnahme _als organisch und mithin als lebend zu
betrachten_.” In a note he adds that physiologists have considered
certain solid parts--epidermis, nail, hair, and bones--to be dead; “but
all these are organically developed, and are in direct connection with
the other parts.”
[25] VIRCHOW, _Die Cellular Pathologie_, 1860, Lect. I.
[26] BEALE, _Bioplasm_, 104.
[27] KÖLLIKER, _Gewebelehre_, 5th ed., 1867, p. 12.
[28] Nevertheless there are some facts directly contradicting his
conclusions. For example, he considers the axis cylinder of the nerve
to be formed material, and agrees with MAX SCHULTZE and others as to
its fibrillated structure; yet according to LISTER and TURNER, GERLACH
and FREY, the axis cylinder is deeply stained by carmine, and in this
respect resembles the nucleus of protoplasm.
[29] From the quite recent experiments M. BAILLON has submitted to the
_Académie des Sciences_ (15th February, 1875), it appears that although
cut flowers absorb colored fluids, the roots when intact only absorb
the fluid, and reject the coloring matters, by a veritable dialysis.
[30] GERLACH cited by RANKE, _op. cit._, p. 76.
[31] STEIN, _Der Organismus der Infusionsthierchen_, 1859, p. 76.
[32] STAHL had a profound conviction of the radical difference,
though he was not able to point out the conditions involved. See his
_Disquisitio de mechanismi et organismi vera diversitate_.
[33] M. FERNAND PAPILLON has shown that animals may be fed with food
deprived of phosphates of lime if its place is supplied with magnesia,
strontia, or alumina; they make their bones out of these as out of
lime. But no such substitution is possible in muscle, nerve, or gland;
we cannot replace the phosphate of magnesia in muscles by the phosphate
of iron, lime, or potash, as we can replace the iron of a wheel by
steel, copper, or brass.
[34] Anatomy resolves the Tissues into Organites (cells, fibres,
tubes); here its province ends, and that of Chemistry begins by
pointing out the molecular composition of the Organites.
[35] This luminous conception, though vaguely seized by PINEL, was
first definitely wrought out by BICHAT. See his _Recherches sur la Vie
et la Mort_--and especially his _Anatomie Générale_, 1812, I. p. lxx.
It was one of the most germinal conceptions of modern times.
[36] Just as there go other materials besides canvas to make a sail,
and others besides iron to make a windlass, so there go other tissues
besides the muscular to form a muscle--there is the membranous
envelope, the nerve, the blood-vessels, the lymphatics, the tendon, and
the fat. Even in Contraction there is another property involved besides
the Contractility of the muscular element, namely, the Elasticity
of the fibrous wall of the muscular tube; but Contractility is the
dominant property, and determines the speciality of the function.
[37] “L’élément musculaire peut être annexé à une foule de mécanismes
divers; tantôt à un os, tantôt à un intestin, tantôt à une vessie,
tantôt à un vaisseau, tantôt à un conduit excréteur, tantôt enfin à des
appareils tout à fait spéciaux à certaines espèces d’animaux.”--CLAUDE
BERNARD, _Rapport sur les Progrès de la Physiologie générale_, 1867, p.
38.
[38] VULPIAN, _Leçons sur la Physiologie du Système Nerveux_, 1866,
p. 581. In a work just published I find M. LUYS hesitating at the
consistent application of this law. After pointing out the identity
of the tissue in cerebrum and spinal cord, he is only prepared
to say that we cannot deny that there is _no impossibility_ in
admitting physiological equivalence where there is morphological
equivalence.--LUYS, _Actions Reflexes du Cerveau_, 1874, p. 14.
[39] It is because men converted the result into a principle, and
supposed that Life preceded the Organism, that they were led to puzzle
themselves over such facts as the continuance of vitality in divided
organisms. ARISTOTLE felt the force of the objection: “Plants when
divided are seen to live, and so are certain insects, as if still
possessing the same Vital Principle (ψυχή) considered specifically
(τῷ εἴδει) though not the same numerically (μὴ ἀριθμῷ). Each of these
parts has sensation and locomotion for a time; and there is no room for
surprise at their not continuing to manifest these properties, seeing
that the organs necessary for their preservation are absent.”--_De
Anima_, Lib. I. Ch. IV. Compare BASSO, _Philos. Naturalis adversus
Aristotelem_, Amsterdam, 1649, p. 260; and TAURELLUS, _Contra
Cæsalpinum_, 1650, p. 850; neither of them grappling with the
difficulty so firmly as ARISTOTLE.
[40] SPENCER, _Principles of Biology_, 1864, I. 153.
[41] Comp. LAMARCK, _Philos. Zool._, II. 114.
[42] Comp. SPENCER, _op. cit._, II. 362, 363, for good illustrations of
this.
[43] AGASSIZ, _Essay on Classification_, p. 91.
[44] “Nulla in corpore animali para ante aliam facta est, et omnes
simul creatæ exiatunt.”--HALLER, _Elementa Physiologiæ_, VIII. 148.
[45] QUATREFAGES, _Metamorphoses de l’Homme et des Animaux_, 1862, p.
42.
[46] VON BAER, _Ueber Entwickelungageschichte_, 1828, I. 221.
[47] Curiously enough, while the Nudibranch, which is without a shell,
possesses one during its embryonic life, there is another mollusc,
_Neritina fluviatilis_, which possessing a shell in its subsequent life
is without one during the early periods, and according to CLAPARÈDE
begins an independent existence, capable of feeding itself before it
acquires one. See his admirable memoir on the _Neritina_, in _Müller’s
Archiv_, 1857.
[48] Has any advocate of the hypothesis that animals were created as
we see them now, fully formed and wondrously adapted in all their
parts to the conditions in which they live, ever considered the hind
legs of the seal, which he may have watched in the Zoölogial Gardens?
Here is an animal which habitually swims like a fish, and cannot use
his hind limbs except as a rudder to propel him through the water; but
instead of having a fish-like tail he has two legs flattened together,
and nails on the toes--toes and nails being obvious superfluities. Now
which is the more rational interpretation, that these limbs, in spite
of their non-adaptation, were retained in rigid adherence to a Plan, or
that the limbs were inherited from an ancestor who used them as legs,
and that these legs have gradually become modified by the fish-like
habits of the seal?
[49] MILNE EDWARDS, _Intro. à la Zoologie Générale_, 1851, p. 9.
[50] VON BAER, _op. cit._, I. 203.
[51] WOLFF, _Theorie der Generation_, 1764, § 67. The reader will find
abundant and valuable corroboration of this biological principle in SIR
JAMES PAGET’S _Lectures on Surgical Pathology_.
[52] VON BAER, _Selbstbiographie_, 1866, p. 319.
[53] MILNE EDWARDS, _Intro. à la Zoologie Générale_, 176.
[54] VON BAER, _Ueber Entwickelungsgeschichte_, I. 147.
[55] LOTZE, art. _Lebenskraft_, in _Wagner’s Handwörterbuch der
Physiologie_, p. XXVI.
[56] I had kept these tritons four years in the hope that they would
breed; but in spite of their being subjected to great varieties of
treatment--for months well supplied with food, and for months reduced
almost to starvation--they never showed the slightest tendency to
breed; another among the many illustrations of the readiness with which
the generative system is affected even in very hardy and not very
impressionable animals. CLAPARÈDE observed the still more surprising
fact that the _Neritina fluviatilis_ (a river snail) not only will not
lay eggs, but will not even feed in captivity. He attributes it to the
stillness of the water in the aquarium, so unlike that of the running
streams in which the mollusc lives. See _Müller’s Archiv_, 1857.
[57] BRONN, _Morphologische Studien über die Gestaltungs-Gesetze_,
1858. Compare the note on § 11.
[58] DARWIN, _On Domestication_, II. 340. In the _Annales des
Sciences_, 1862, p. 358, M. MALM describes a fish in his collection,
the tail of which had been broken, and the bone which grew out at the
injured spot had formed a second tail with terminal fin.
[59] In the memoir on the _Anatomy and Physiology of the Nematoids_,
by Dr. CHARLTON BASTIAN, which appeared in the _Philosophical
Transactions_ for 1866, we read that even these lowly organized
worms have little power of repair. Speaking of the “paste eels”
(_Anguilulidæ_), he says, “I may state as the result of many
experiments with these that the power they possess of repairing
injuries seems very low. I have cut off portions of the posterior
extremity, and though I watched the animal for days after, could never
recognize any attempt at repair.” Perhaps, however, the season may have
some influence; and Dr. WILLIAMS’S denial respecting the Naïs may be
thus explained. [What is said above was written in 1868, and published
in the June number of the _Fortnightly Review_. In the August of that
year the question of reproduction of lost limbs was treated by Prof.
ROLLESTON in his _Address to the British Medical Association_, in which
he showed cogent evidence for the conclusion that the reproduction
of limbs only exists is animals that have feeble respiration, and
consequently slow vital processes.]
[60] This beautiful and transparent larva reminds one in many respects
of the Pike as it poises itself in the water awaiting its prey. It is
enabled to do so without the slightest exertion by the air-bladders
which it possesses in the two kidney-shaped rudiments of tracheæ, and
which in the gnat become developed into the respiratory apparatus. The
resemblance to the air-bladder of fishes is not simply that it serves
a similar purpose of sustaining the body in the water, it is in both
cases a rudiment of the respiratory apparatus, which in the fish never
becomes developed. WEISMANN calls attention to an organ in the larvæ of
certain insects (the _Culicidæ_), which have what he calls a tracheal
_gill_, which gill has this striking analogy with the fish-gill that
it separates the air from the water, and not, as a trachea, direct
from the atmosphere. See his remarkable memoir _Die nachembryonale
Entwickelung des Muscidens_, in _Siebold und Kölliker’s Zeitschrift_,
1864, p. 223.
[61] _The Variation of Animals and Plants_, 1868, II. p. 272.
[62] _Origin of Species_, 5th ed. p. 96.
[63] Mr. Darwin has himself, in the following passage, stated a
somewhat similar view, and rejected it: “In one sense the conditions of
life may be said not only to cause variability, but likewise to include
Natural Selection, for _the conditions determine whether this or that
variety shall survive_. But when man is the selecting agent, we clearly
see that the two elements of change are distinct; the conditions
cause the variability, the will of man acting either consciously or
unconsciously accumulates the variations in certain directions, and
this answers to the survival of the fittest under nature.” (p. 168.)
[64] Even in the nerve-sheaths of some Annelids there are muscles.
[65] SPENCER, _Principles of Biology_, II. 72
[66] FAIVRE, _Variabilité de l’Espèce_, p. 15.
[67] These luminous organs would furnish an interesting digression
if space permitted it. The student is referred to the chapter in
MILNE EDWARDS’S _Leçons sur la Physiologie et l’Anatomie Comparée_,
1863, VIII. 94, sq. LEYDIG, _Histologie_, 1857, p. 343. KÖLLIKER,
_Microscopical Journal_, 1858, VIII. 166, and MAX SCHULTZE, _Archiv
für mikros. Anat._, 1865, p. 124. My friend SCHULTZE was kind enough
to show me some of his preparations of the organs of _Lempyris
splendidula_, from which the drawings in his memoir were made.
They reminded me of the electric organs in fishes by a certain
faint analogy, the trachea in the one holding the position of
nerves in the other. I may remark, in passing, that it is not every
phosphorescent animal that has distinct luminous organs. There is a
lizard (_Pterodactylus Gecko_) which occasionally becomes luminous. “A
singular circumstance occurred to the colonial surgeon, who related it
to me. He was lying awake in bed when a lizard fell from the ceiling
upon the top of his mosquito-curtain; at the moment of touching it the
lizard became brilliantly luminous, illuminating the objects in the
neighborhood, much to the astonishment of the doctor.” COLLINGWOOD,
_Rambles of a Naturalist_, 1868, p. 169.
[68] MAX SCHULTZE, _Zur Kenntniss der electrischen Organe der Fische_,
1858–9.
[69] LEYDIG, _Histologie_, 1857, p. 45.
[70] OWEN, _Anatomy of The Vertebrates_, 1866, I. 358.
[71] DAVY, _Researches, Physiological and Anatomical_, 139, I. 33.
[72] “If it could be demonstrated that any complex organ existed
which could not possibly have been formed by numerous successive
slight modifications, my theory would absolutely break down.”--DARWIN,
_Origin of Species_, 5th ed. p. 227. In several passages insistence
is made on this. “Natura non facit saltum” may be perfectly true; but
without impugning the Law of Continuity we may urge that the Law of
Discontinuity is equally true. The one is an abstract ideal conception;
the other is a concrete ideal conception. According to the one, every
change from rest to motion, or from one state to another, must pass
through infinites; according to the other every change is abrupt.
In my First Series, Vol. I. p. 327, I have shown how, on mechanical
principles, every change in an organism must be abrupt. A glance at
the metamorphoses of the embryo, or the stages of insect-development,
will show very sudden and abrupt changes. Let me also cite Mr. Darwin
against himself: “When we remember such cases as the formation of
the more complex galls, and certain monstrosities, which cannot be
accounted for by reversion, cohesion, etc., and _sudden, strongly
marked deviations of structure_, such as the appearance of a moss-rose
on a common rose, we must admit that the organization of the individual
is capable through _its own laws of growth, under certain conditions_,
of undergoing great modifications, independent of the gradual
accumulation of slight inherited modifications.”--_Origin_, p. 151. See
also note to § 130, further on, p. 142.
[73] On the Nutrition of Monads, see the remarkable memoir by
CIENKOWSKI, in the _Archiv für mikros. Anatomie_, I. 221, sq.
[74] PAGET, _Lectures on Surgical Pathology_, edited by TURNER, 1865,
p. 19.
[75] It has recently been shown that certain Crustacea vary not only
from species to species, but from genus to genus, when living in
water of different degrees of saltness. By continued dilution of the
salt water an _Artemia_ was developed into another species, and this
again into a _Branchipus_--a genus of large dimensions, with an extra
abdominal segment, and a different tail; a genus, moreover, which is
propagated sexually, whereas the _Artemia_ is parthenogenetic, as a
rule. See _Nature_, 1876, June 8, p. 133.
The exceeding importance of this fact is, that it proves specific
and even generic differences to originate simply through the gradual
changes of the medium and the adaptation of the organism to these new
conditions. It also disproves the very common notion--adopted even
by Mr. DARWIN himself--that “organic beings must be exposed _during
several generations_ to new conditions to cause any appreciable amount
of variation.” Again, “Natural Selection, if it be a true principle,
will banish the belief of any great and sudden modification of
structure.”--Comp. note to § 121, p. 132.
[76] Compare LEYDIG, _Vom Bau des thierischeu Körpers_, 1864, p. 27.
[77] FERDINAND COHN, _Die contractile Gewebe im Pflanzenreich_, 1862.
By a series of numerous well-devised experiments, Cohn found that in
the stamen of the _centauria_ a tissue exists which is excitable by the
same stimula as muscle is, and which reacts like muscle, describing a
similar curve when excited, and, after reaching its maximum, relaxing.
Like the muscle it becomes fatigued by repeated contraction, and
recovers its powers by repose. Like the muscle it may be rendered
tetanic. (The researches of Dr. BURDON SANDERSON and Mr. DARWIN have
since placed beyond a doubt the Contractility and Sensibility of
certain plants.)
[78] MIVART, _The Genesis of Species_, 1871, p. 23.
[79] DOHRN, _Der Ursprung der Wirbelthiere und das Princip des
Functionswechsels_, 1875, p 74.
[80] SIGMUND MAYER, _Die peripherische Nervenzelle und die sympathische
Nervensystem_, 1876.
[81] On these cells see note to § 140.
[82] These terms designate the surface aspect of a transverse section,
of what more correctly should be called the gray columna. See Figs. 3
to 6.
[83] But this only in the higher animals. In reptiles and amphibia the
medulla descends into the cervical region, as far as the second and
third cervical vertebræ. This should be remembered in experimenting.
[84] FOSTER and BALFOUR, _Elements of Embryology_, Part I., 1874. Comp.
SCHWALBE, art. _Die Retina_, in the _Handbuch der Augenheilkunde_ of
GRAEFE _and_ SÄMISCH, 1874, I. 363.
[85] The development of the olfactory lobe and bulb is similar; it need
not be followed here.
[86] German anatomists divide this axis into trunk and crown
(_Hirnstamm_ and _Hirnmantel_). There is convenience in this division.
If we remove all the gray matter of the cerebrum, with all the white
matter radiating from it, until we again come upon gray matter--and
if we then cut the cerebellum from its descending strands of white
matter--we shall have removed the _crown_, and leave the _trunk_
remaining. This trunk is constituted by the corpora striata, nucleus
lentiformis, optic thalami, corpora quadrigemina, crura cerebri, pons,
medulla oblongata, and medulla spinalis. From this trunk all the organs
of the body are directly innervated (except those innervated from the
sympathetic?).
[87] “On s’est préoccupé du rôle spécial que pouvaient jouer les
ganglions périphériques situés dans le voisinage de certaines organes;
et on a prétendu que les nerfs ne jouissaient de leur propriété d’agir
sur ces organes qu’après avoir traversé ces ganglions. On avait admis
que l’excitation portée sur le filet nerveux avant son entré dans le
ganglion restait sans effet; que pour obtenir l’action excitatrice
des fonctions de l’organe il fallait exciter le nerf entre lui et le
ganglion voisin.”--CLAUDE BERNARD, _Systéme Nerveux_, II. 169. But on
proceeding to verify these statements by experiment, BERNARD is led to
the conclusion, “que le ganglion n’a pas d’influence propre sur le mode
de l’excitation transmise à l’organe.”
I was delighted to find my opposition to the current teaching
respecting the central functions of ganglionic cells thoroughly
borne out by the elaborate researches of SIGMUND MAYER (_Archiv für
Psychiatrie_, Bd. VI. Heft 2). Having artificially produced such cells,
he pertinently asks, How can we attribute central functions to cells
which appear in the process of regeneration of a divided nerve! The
error has its origin in the confusion of functions with properties.
[88] It is often, though incorrectly, stated that every segment of an
annulose animal has its separate ganglion. The fact is, that while the
ganglia are usually fewer than the segments, they are sometimes more
numerous.
[89] It has been proved that the cells of the cornea and the pigment
cells of the skin contract under nervous excitation. We cannot suppose
that although these are the only cells which have hitherto been brought
under experimental observation, they are the only cells subject to
nerve-influence. We may safely assume that wherever a nerve-fibre
terminates, its action will be transformed into an excitation of the
part. Habitually, however, motor-nerves are spoken of as muscle-nerves.
[90] On Deduction, see _Problems: First Series_, Vol. II. p. 159
[91] I do not here touch upon the question as to whether these actions
of the senses are _sensations_, because that question demands that
we should first settle what is _Sensation_. I may at once, however,
say that what is ordinarily understood as a sensation of _color_,
or a sensation of _sound_, is, in my opinion, not possible without
the cerebrum. But the sensibility of the eye and ear is manifestly
preserved.
[92] It has been observed that removal of the cerebellum affects the
pigment cells of the skin. No doubt other parts are also affected, but
the changes have hitherto escaped observation.
[93] OWSJANNIKOW describes the results of removing carefully the
cranial ganglia of the crayfish; and these effects MEYER observes to
be identical with those which follow removal of the large claw of
the crayfish! A. B. MEYER, _Das Hemmungsnerven-system des Herzens_,
1869, p. 23. Let me add that the phenomena described by M. FAIVRE
as following the destruction of one subœsophageal ganglion in the
_Dytiscus_, are so little to be referred to the mere absence of the
ganglion, that I find them not to occur when the whole head is removed.
[94] PFLÜGER, _Die Sensorischen Funktionen des Rückenmarks_,1858.
AUERBACH, _Günzburg’s Zeitschrift_. Jahrgang IV. p. 486. LEWES, _Leeds
Meeting of British Association_, 1858, and _Physiology of Common Life_,
1860.
This recognition of sensation, and even of volition, in spinal actions
may be found in the writings of WHYTT, UNZER, PROCHASKA, LEGALLOIS, and
MAYO; but the establishment of the Reflex Theory had displaced it, and
its revival dates from PFLÜGER.
[95] FRIEDLÄNDER (_Versuch über die innern Sinne_, 1826, I.
77) declares it to be a rational necessity: “Die Annahme eines
Nervenfluidums ist Nothwendigkeit der Vernunft.”
[96] These terms and the conception they embody were proposed by me in
1859 in a paper “On the necessity of a reform in Nerve-physiology,”
read at the Aberdeen meeting of the British Association, and were
reproduced in the _Physiology of Common Life_. (Prof. OWEN, probably
in forgetfulness of my suggestion, proposed “neuricity.” _Lectures
on the Comp. Anat. of Vertebrates_, 1866, I. p. 318.) The terms were
fortunate enough to meet with acceptance from some physiologists
both in England and France; and the conception has been more widely
accepted than the terms. The most distinguished approver was Prof.
VULPIAN. “Faute d’une meilleure détermination on peut, avec M. Lewes,
donner à la propriété physiologique des fibres nerveuses le nom de
_neurilité_; c’est là ce qui correspondra à la oontractilitè des fibres
musculaires.” _Leçons sur la physiologie du système nerveux_, 1866, p.
220. He also adopted my suggestion (since modified) of Sensibility as
the property of ganglionic cells. Compare also GAVARRET, _Phénomènes
physiques de la Vie_, 1869, pp. 213 and 222. TAULE, _Notions sur la
nature de la matière organisée_, 1866, p. 131. CHARLES ROBIN, _Anatomie
et physiologie cellulaires_, 1873, p. 166.
By these channels, and by the German, Italian, Russian, Polish, and
Hungarian translations of my work, the suggestions were carried over
Europe, crept into scientific journals, and became known to writers who
never heard of me. I only mention these facts lest the reader should
suppose that my views had been anticipated by certain continental
writers.
[97] “La force nerveuse n’existe pas comme puissance independant des
propriétés de tissu. Elle consiste en l’action des parties excités, sur
les parties excitables, l’état de l’excitation des premières agissant
comme impression ou stimulation sur les secondes.”--LANDRY, _Traité des
Paralysies_, 1859, I. 142.
[98] “Le système nerveux est tout à la fois l’origine des sensations
et l’origine des mouvements. Mais est-ce par une propriété unique, ou
par deux propriétés diverses qu’il détermine deux phénomènes aussi
distincts!” FLOURENS, _Recherches sur les propriétés et les fonctions
du Système Nerveux_, 1824, p. 1. He concludes that “la puissance
nerveuse n’est pas unique; il n’y a pas une seule propriété, il y en a
deux,” p. 24. In this he has been generally followed.
[99] “I have raised and stretched the thick orbital nerve of horses
on the handle of a scalpel, like a string on the bridge of a violin,
without exciting the least sensation; but as soon as mechanical or
chemical irritation had given rise to inflammation of the nerve a
gentle touch caused violent pain.”--ROMBERG, _Nervous Diseases_
(translated for the Sydenham Society), I. 10.
[100] The experiments of HALLER, _Sur la nature sensible et irritable
des parties_, I. 245; and the remarks of PROCHASKA, DE FUNCTIONIBUS
SYSTEMATIS NERVOSI (translated by LAYCOCK in the volume published by
the _Sydenham Society_, p. 396), ought to have sufficed. See further
on, Chap. V.
[101] In mammals about three days, in birds four days, in frogs
fourteen to twenty days.
[102] RUTHERFORD, in _Journal of Anatomy_, 1873, No. VIII. p. 331.
(FLEISCHL denies that the nerve _in situ_ has different degrees of
reaction. _Sitzungsberichte der Wiener Akad._, December, 1876.)
[103] MUNK, in the _Archiv für Anat._, 1860, p. 798.
[104] HALLER, _Mémoires sur la nature sensible et irritable des
parties_.
[105] _Comptes Rendus_, 1862, LIV. p. 965.
[106] “J’espère vous convaincre que tous les éléments anatomiques
des nerfs sensitifs, moteurs, vasomoteurs, et autres, ont les
mêmes propriétés, et ne sont distincts que par leurs fonctions.
Cette question est de la plus haute importance pour la physiologie
générale. C’est celle qui domine toute la physiologie des fibres
nerveuses.”--VULPIAN, _Leçons sur la Physiologie du Système Nerveux_,
p. 11.
[107] Mr. JAMES ANDREWS.
[108] In the second number of _La Revue Philosophique_, Paris, 1876, I
have treated this question of specific energies more at length than I
could find space for in the present volume.
[109] In 1859 I mentioned that if the nerves of a frog’s back be
exposed by raising the skin, they may be pricked or even cut without
sensible effect, although a slight prick on the skin will excite the
nerves, and cause a reflex action. In 1870, Prof. FICK expressed his
astonishment at finding that after he had cut out a piece of the
skin, leaving it attached to the body by a single nerve, electrical
stimulation of this excised skin caused the frog to make the reflex
movement of rubbing the irritated surface; whereas electrical
stimulation of the nerve-trunk itself produced no reflex effect, only a
twitching of a muscle. _Pflüger’s Archiv_, 1870, p. 327. BROWN SÉQUARD
tries to establish a distinct species of nerves as _conductors_ of
sensitive impressions, from those which are _impressionable_. The
facts on which he founds these two properties simply show that nerves
are so disposed that the stimulus which excites them in one place
fails in another. He could hardly maintain that a skin nerve contained
impressionable fibres at its periphery, and only conducting fibres in
its trunk! See his communication to the Royal Society, _Proceedings_,
1856; and _Lectures_ in the _Lancet_, 10th July, 1858.
[110] In consequence of this observation some physiologists have
maintained that Feeling or Consciousness never arises in cerebral
activity, unless the thalami and the connected tracts are at the
same time in action. I go further, and maintain that there is no
Consciousness (in the restricted meaning of the term) _unless the whole
organism is involved_. Cerebral or spinal activity will be activity of
Sensibility; but this is only the basis of Consciousness.
[111] “An unconscious sensation, which Lewes distinguishes
from perception, is to me an inconceivable (ist für mich
ein Unding).”--SCHRÖDER VAN DER KOLK, _Die Pathologie des
Geistes-Krankheiten_, p. 22.
[112] By selective adaptation is meant the varying combination of motor
impulses to suit the varying requirements of the effect to be produced.
Physical mechanisms are limited to the performance of definite actions;
sensitive mechanisms employ fluctuating combinations of elements in
response to fluctuations of stimuli. The wheels, levers, springs, and
valves of a machine cannot be differently combined according to varying
degrees of the motor-force, as the nerves and muscles of an organism
are differently combined by varying sensations. An automaton may be
constructed to play on the violin, but it will only play the air to
which it is _set_; it cannot vary the performance,--cannot play a false
note, or throw in a _crescendo_ here, a _largo_ there, according to a
caprice of feeling. We must admit that violinist has his delicate and
changing movements guided by sensations, auditory and muscular; any
interruption in the sensations would arrest the movements, which in
truth _incorporate_ them. And yet it is well known that the violinist
may perform while completely “unconscious.” I do not simply refer to
the fact that his thoughts and attention may be elsewhere; I refer to
such facts as are recorded in Pathology. TROUSSEAU, for example, had an
epileptic patient who was occasionally seized with attacks of complete
unconsciousness while he was performing in the orchestra; yet, on
reawakening to consciousness, he found that he had continued to play,
had kept proper time, and played the proper notes.
[113] CLAUDE BERNARD, _Système Nerveux_, 1858, I. 349.
[114] WORDSWORTH, _The Prelude_.
[115] “On peut dire que toujours un phénomène de mouvement reconnait
pour point de départ une impression sensitive.”--CLAUDE BERNARD, I. 267.
[116] Since this was written Prof. MICHAEL FOSTER and Mr. DEW SMITH
have published their very important researches on the motions of the
heart, which establish beyond a doubt that, in the molluscs at least,
there is no co-operation of either centre or nerve.--_Proceedings of
the Royal Society_, 18th March, 1875. (_See also Studies from the
Physiological Laboratory of Cambridge_, Part II., 1876.) Mr. Foster
knows that I had independently, and from a totally different line
of research, arrived at the same conclusion respecting the heart’s
movement.
[117] _Comptes Rendus de la Socíété de Biologie_, 1847, I. 40. In
1856 he showed that not only were the muscles of the iris directly
stimulated by light (and this not by its calorific or chemical rays),
but that sixteen days after removal of the eye from the orbit, this
effect was observable in the eel. Yet a very few days after extirpation
of the eye the nerves are disintegrated.--_Proceedings of the Royal
Society_, 1856, p. 234.
DONDERS has the following observations: “The movements of the iris
are of two kinds--reflex and voluntary. Reflex action is exhibited as
constriction of the pupil in consequence of the stimulus of incident
light upon the retina. Fontana has shown that the light falling upon
the iris produces no remarkable contraction. We have confirmed this
result by causing the image of a small distant light to fall, by means
of a convex lens, upon the iris, whereby, during slight perception of
light, a doubtful contraction occurred, which gave way to a strong
contraction so soon as the light entering the pupil excited a vivid
perception. Nevertheless, the experiments of Harless and Budge have
shown that even after death, so long as irritability remains, the pupil
still contracts upon the continued action of light. Of the correctness
of this we have satisfied ourselves. In a dog killed by loss of blood
the one eye was closed, the other opened and turned to the light: after
the lapse of an hour, the pupil of the opened eye was perceptibly
smaller than that of the closed eye. The latter now remained also
exposed to the light, and on the following day the diameter of both
eyes was equal. The upper jaw, alone with the eyes, was taken out of
some frogs; one eye was exposed to the light, while the other was
covered with a closely folded piece of black paper: after the lapse of
half an hour the pupil turned to the light was narrow, the other wide.
But the latter also contracted almost immediately after the removal of
the paper.”--DONDERS, _On the Anomalies of Accommodation and Refraction
of the Eye_. Trans. of the New Sydenham Society, p. 572.
[118] The experiment often fails, but I have seen it several times
succeed.
[119] _Pflüger’s Archiv_, 1872, p. 618.
[120] See his Researches in _Pflüger’s Archiv, Bde._ II. and IV.
[121] D’ORBIGNY, _Des Mollusques Vívants et fossils_, p. 113.
[122] _Seaside Studies_, 2d ed., p. 101.
[123] Cited by BROWN SÉQUARD, _Journal de la Physiologie_, 1858, p. 359.
[124] Dr. NORRIS has recorded some striking observations in his paper
on “Muscular Irritability” in the _Journal of Anatomy_, 1867, No. II.
p. 217. Here is the only one I can find room for: “On taking up the
_dead_ frog and touching the limb (which during life had been paralysed
by section of its nerve) with my finger, _it was suddenly shot out
as if alive_. I placed the body down, and one or two _apparently
spontaneous movements_ of small extent afterwards occurred. On touching
the skin gently with the point of a needle, by the slight pressure upon
the muscle beneath, movements of the limb were also induced, but this
high degree of exaltation very rapidly disappeared.”
[125] See their papers in the _Archiv für Psychiatrie_, 1875, Bd. V.
Heft 3.
[126] This latter statement will be justified when I come to expound
the Triple Process, which I have named the _Psychological Spectrum_.
[127] FOSTER and BALFOUR, _Elements of Embryology_, 1874, Part I. p.
52. HIS, _Untersuchungen über die erste Anlage des Wirbelthierleibes_,
1868, p. 197.
[128] They state that the cells of the epiblast are the results
of direct segmentation, whereas the cells of the other layers are
formed at a subsequent period, and are only indirectly results of
segmentation. But if the observations of KOWALEWSKY are exact, this is
not the case with the hypoblast of the Amphioxus, which is from the
first identical with the epiblast.
[129] KÖLLIKER, _Entwicklungsgeschichte des Menschen und der höheren
Thiere_, 1861, p. 71.
[130] [According to BALFOUR’S recent observations, a large part of the
muscular tissue is derived from the layer of the mesoblast belonging to
the hypoblast.]
[131] HIS, _Untersuchungen_, pp. 39, 40.
[132] Quite recently OWSJANNIKOW has pointed out the termination of
fibres in the phosphorescent cells of the _Lampyris Noctiluca_. See his
paper in the _Mémoires de l’Acad. de St. Petersbourg_, 1868, XI. 17.
These phosphorescent cells are said to be ganglion-cells by PANCERI,
_Intorno della luce che emana dalle celleule nervose_ (Rendiconto della
Accad. delle Scienze, April, 1872); and by EIMER, _Archiv für mikros.
Anatomie_, 1872, p. 653. KÖLLIKER also calls the phosphorescent organ a
nervous organ. This is not to be interpreted as meaning that neurility
is phosphorescence, but simply that in some nerve-cells there is
phosphorescent matter, which is called into activity by stimulus of the
nerves.
[133] BIDDER und KUPFFER, _Textur des Rückenmarks_, 1857, p. 108.
[What is said in the text has been rendered doubtful by the recent
researches of Mr. F. BALFOUR, _On the Development of the Spinal Nerves
in Elasmobranch Fishes_ (_Philos. Trans._, Vol. CLXVI. Part I.), which
show that in these fishes the ganglion has its origin in the spinal
cord.]
[134] Comp. PROBLEM I. § 130, with the remarks of CHARLES ROBIN,
_Anatomie et Physiologie Cellulaires_, 1873, p. 20.
[135] KLEINENBERG, _Hydra; Eine Anatomisch-Entwickelungs-Untersuchung_,
1872, p. 11. EIMER, _Zoologische Studien auf Capri_, 1873, p. 66.
A similar formation is described by Dr. ALLMAN in the _Myriothela_; he
says, however, that he has never been able to trace a direct continuity
of the caudal processes of the cells with muscular fibrils. He believes
that the processes make their way to the muscular layer through
undifferentiated protoplasm.--_Philos. Transactions_, Vol. CLXV. Part
II. p. 554.
An intermediate stage between this neuro-muscular tissue and the two
differentiated tissues seems presented in the Nematoid worms which
have muscles that send off processes into which the nerves pass.
GEGENBAUR declares his inability to decide whether these processes are
muscles or nerves. BÜTSCHLI thinks the nerve-process blends with the
muscle-process.--_Archiv für mikros. Anatomie_, 1873, p. 89.
[136] “The gray matter of the cord seems undoubtedly to be formed by a
metamorphosis of the external cells of the epiblast of the neural tube,
and is directly continuous with the epithelium; there being no strong
line of demarcation between them.”--_Op. cit._, p. 185.
[137] ROBIN, _Anat. et Physiol. Cellulaires_, p. 332.
[138] STILLING, _Bau der Nervenprimitiv-Fasern_, 1856, p. 16.
[139] “There was a time,” says KÖLLIKER, “when I confidently believed
that an hypothetical explanation of the arrangement of elements in
the spinal cord could be grounded on a basis of fact; but the deeper
my insight into the minute anatomy, the less my confidence became;
and now I am persuaded that the time is not yet come to frame such an
hypothesis.”--_Gewebelehre_, 5te Auf. 1867.
[140] In the Gasteropoda the cells range from 220 μ to 3 μ (μ = 0,001
millimètre).
[141] HAECKEL, _Müller’s Archiv_, 1857. LEYDIG, _Vom Bau des
thierischen Körpers_, 1864, I. 84. ROBIN, _Anat. et Physiol.
Cellulaires_, p. 89. Should the observations of HEITZMANN be
confirmed, there would be ground for believing that neurine is
normally fibrillated. He says that the living protoplasm in the
Amœba, white blood-corpuscle, etc., is an excessively fine network,
which condenses into granules at each contraction. (Cited in the
_Jahresberichte über Anat. und Physiol._, 1873, Bd. II.) WALTHER, who
examined frozen brains, describes the cells as quite transparent at
first, with very rare granules, but gradually while under observation
the granules became more numerous. _Centralblatt_, 1868, p. 459.
According to MAUTHNER, _Beiträge zur Kenntniss der morphologischen
Elemente des Nervensystems_, 1862, p. 41, neurine has three cardinal
forms--transparent, finely granular, and coarsely granular.
[142] TRINCHESE, _Struttura del sistema nervoso dei Cefalopodi_,
Florence, 1868, p. 7.
[143] An eminent friend of mine was one day insisting to me that the
physiological postulate made it _impossible_ for a nerve-cell to be
without its ingoing and outgoing fibres; and he was not a little
astounded when I replied, “Come into my workroom and I will show you a
thousand.”
[144] EICHHORST in _Virchow’s Archiv_, 1875, LXIV. p. 432.
[145] AUERBACH (_Ueber einen Plexus Myentericus_, 1862) describes
the ganglia as filled with apolar cells, among which only a few are
unipolar. STIEDA (_Centralnervensystem der Vögel_, 1868) finds both
apolar and unipolar cells in the spinal ganglia of birds. AXMANN (_De
Gangliorum Systematis Structura penitiori_, 1847) says the spinal cells
are all unipolar. SCHWALBE (_Archiv für mikros. Anat._, 1868) and
COURVOISIER (_ibid._, 1869) say the same. So also RANVIER, _Comptes
Rendus_, 1875. KÖLLIKER (_Gewebelehre_) speaks decidedly in favor of
both apolar and unipolar cells, but thinks the apolar are embryonic.
PAGLIANI (_Saggio sullo Stato attuale delle Cognizioni della Fisiologia
intorno al Sistema nervoso_, 1873), who represents the views of
MOLESCHOTT, admits the existence of apolar and unipolar cells. The
authors just cited are those I happen to have before me during the
rewriting of this chapter, and the list might easily be extended if
needful. AUERBACH, BIDDER, and SCHWEIGGER-SEIDEL describe unipolar
cells which in some places present the aspect of bipolar cells simply
because two cells lie together, their single poles having opposite
directions. I will add that the bipolar cells do not really render the
physiological interpretation a whit more easy than the unipolar, for
they are simply cells which form enlargements in the course of the
nerve-fibres.
[146] When Dr. BEALE says “that it is probable no nerve-cell exists
which has only _one single fibre_ connected with it” (_Bioplasm_, p.
186), he has no doubt this in his mind; since he would not, I presume,
deny that there are cells each with a single _process_.
[147] DEITERS, _Untersuchungen über Gehirn und Rückenmark_, 1865.
[148] _Archiv für mikros. Anat._, 1869, p. 217. Compere also BUTZKE,
_Archiv für Psychiatrie_, 1872, p. 584.
[149] HENLE, _Nervenlehre_, 1871, p. 58, Fig. 21.
[150] When men of such experience and skill as KÖLLIKER, BIDDER, GOLL,
and LOCKHART CLARKE declare that they have never seen a cell-process
pass directly into a dark-bordered fibre in the anterior root, what
are we to say to such figures and descriptions as those given in the
works of SCHRÖDER VAN DER KOLK, GRATIOLET, and LUYS? Even did such
arrangements exist, no transverse nor longitudinal section could
display them, owing to the different planes at which the fibres enter,
and the length and irregularity of their course.
[151] Long after the text was written, WILLIGK published in _Virchow’s
Archiv_, 1875, LXIV. p. 163, observations of anastomoses which even
KÖLLIKER admitted to be undeniable. Yet out of sixty-four preparations,
amid hundreds of cells, he could only reckon seven cases of conjunction.
[152] See the history given in STILLING’S learned work, _Ueber den Bau
der Nervenprimitiv-Faser_, p. 34; and compare MAX SHULTZE, _De Retinæ
Structura_, p. 8, and _Bau der Nasenschleimhaut_, p. 66; WALDEYER, in
the _Zeitschrift für rat. Med._, 1863; LISTER and TURNER, _Observations
on the Structure of Nerve-Fibres_, in _Quarterly Micros. Journal_,
1859; RANVIER, in the _Archives de Physiologie_, 1872.
[153] _Virchow’s Archiv_, Bd. LXXII. p. 193.
[154] _Monthly Journal of Micros. Science_, 1874, XI. p. 214.
[155] BABUCHIN, _Centralblatt_, 1868, p. 756.
[156] Even so eminent an authority as W. KRAUSE holds this both with
regard to the varicose aspect and the double contour: _Handbuch der
menschlichen Anatomie_, 1876, I. 367. BUTSCHLI, however, describes the
nerves in a living Nematode as varicose: _Archiv für Anat._, 1873, p.
78; and I have somewhere met with an observation of the double contour
being visible in the living animal.
[157] BUTZKE, _Archiv für Psychiatrie_, 1872, p. 594, states that the
granular substance has the chemical composition of myeline. If this
be so, we may suppose the “fibrils of crystallization” to represent
the coagulation of the substance which is in solution amid the myeline
granules, and corresponds with the axis cylinder of a fibre. I may
remark that in almost every good preparation nerve-cells will be found
in which, while one process is distinctly granular, another is striated
or even fibrillated.
[158] BOLL, _Die Histiologie und Histiogenese der nervösen
Centralorgane_, in the _Archiv für Psychiatrie_, 1873, p. 47.
[159] STIEDA, _Studien über das Centralnervensystem der Vögel_, 1868,
p. 65. MAUTHNER, _Op. cit._, p. 4.
[160] TURNER and LISTER, _Op. cit._, p. 8.
[161] BLESSIG, _De Retinæ Structura_, 1857.
[162] LUYS, _Recherches sur le Système nerveux_, 1865, p. 267. In a
recent and remarkable treatise the student is informed that “plus
une cellule est chargée d’un rôle purement mécanique plus elle est
volumineuse; plus l’acte qu’elle produit tend à revêtir un caractère
psychique plus elle est petite”; to move a limb the _agitation_ of
the cerebral cells must _materialize itself_ more and more, “Il a
besoin de passer par des cellules, de moins en moins spirituelles et
de plus en plus matérielles.... De même pour les cellules sensitives.
L’impression extérieure va en se modifiant, en se spiritualisant, de la
périphérie au centre.... Un phénomène de l’ordre spirituel ne sanrait
devenir sans transition un phénomène d’ordre physique.” And what is
this marvellous transition between spiritual and physical? It is the
action of medium-sized cells which “travaillent la vibration reçue, la
modifient de façon à lui ôter de son spiritualisme et à la rapprocher
davantage des ébranlements physiques.” I will not name the estimable
author, because he is simply restating what many others implicitly or
explicitly teach; but I will only ask the reader to try and realize in
thought the process thus described.
[163] SCHRÖDER VAN DER KOLK, _Pathologie der Geisteskrankheiten_, 1863,
p. 69.
[164] WUNDT, _Physiologische Psychologie_, p. 261. In his _Mechanik
der Nerven, 2 Abth._ (published just as this sheet is going to press),
he shows that a stimulus is both retarded and weakened in its passage
through a ganglion.
[165] TRINCHESE also says that the fibres “provengono dalle cellule e
_non son altro che i loro prolungamenti o poli_.”--_Op. cit._, p. 13.
An unequivocal example is seen in the _Torpedo_, where the large cells
have each their prolongation continuing without interruption into the
electrical organ. See the figure given by REICHENHEIM in the _Archiv
für Anat._, 1873, Heft VI.
[166] GOLGI, _Sulla struttura della sostanza grizia del Cervello_.
ARNDT, _Archiv für mikros. Anat._ 1870, p. 176. RINDFLEISCH also traces
these processes into the neuroglia (_ibid._, 1872, p. 453). “Deiters,
Boddaert, and other observers have stated that one dark-bordered
nerve-fibre enters each cell.... My own observations lead me to
conclude that _all_ the fibres are composed of the same material, but
that one fibre does not divide until it has passed some distance from
the cell, while others give off branches much closer to it.”--BEALE,
_Bioplasm_, p. 189.
[167] BEALE, _Bioplasm_, p. 177. MAX SCHULTZE, in _Stricker’s
Handbuch_, p. 134. Comp. STILLING, _Nervenprimitiv-Faser_, p. 133.
ARNDT, _Archiv_ _für mikros. Anat._, 1868, p. 512; and 1869, p. 237.
Weighty as these authorities are, their view is questionable--firstly,
because the forms of these cells are too constant and definite in
particular places to result from the union of fibrils coming from
various origins; but secondly, and mainly, because the teaching of
Development is opposed to it.
[168] ROBIN, _Anat. et Physiol. Cellulaires_, p. 335.
[169] _Archives de Physiologie_, 1872, p. 268.
[170] The fact of the existence of cells in the white substance is one
which is very difficult of interpretation on the current hypotheses.
The cells are found in regular columns and irregularly scattered.
BOLL thinks that while in the white substance of both cerebrum and
cerebellum there are true nerve-cells as well as connective corpuscles,
in the cord there are only the latter. But hitherto there has been
no decisive test by which a nerve-cell can be distinguished from a
connective corpuscle.
[171] _Monthly Journal of Micros. Science_, XI. 219. This accords
with what KUPFFER says respecting the entire absence of cells
in the earliest stages observed by him in the sheep. The white
substance of the spinal cord he describes as soft, transparent, and
gelatinous, in which dark points are visible; these dark points are
seen in longitudinal sections to arise from the fibrillation of the
substance.--BIDDER und KUPFFER, _Op. cit._, p. 111.
[172] WEISMANN, _Die nachembryonale Entwick. der Musciden_, in the
_Zeitschrift für Wissen. Zoologie_, 1864, Bd. XIV. Heft III.
[173] The suggestion in the text has since received a striking
confirmation in the observations of SIGMUND MAYER on the regeneration
of nerves. The nerve when divided rapidly undergoes fatty degeneration,
which is succeeded by a transformation of the myeline and axis cylinder
into a homogeneous mass; in this resolved pulp new longitudinal
lines of division appear, which subsequently become new fibres,
and new nuclei are developed in the remains of the untransformed
substance.--_Archiv für Psychiatrie_, Bd. VI. Heft II.
[174] Strong confirmation of various statements in the text, since
they were written, has been furnished by the researches of EICHHORST,
published in _Virchow’s Archiv_, LXIV. Our knowledge of the development
of nerve-tissue in human embryos is so scanty that these researches
have a great value. EICHHORST describes the striation of the cells in
the cord to begin only at the fourth month; up to this time they are,
what I find most invertebrate cells to be, granular, not fibrillar.
There is very slight branching of the cell processes until the ninth or
tenth month, when the multipolar aspect first appears; the cells are
unipolar up to the end of the fourth month. The connection between the
white columns and the gray columns is very loose up to the fifth month;
and the two are easily separated. Subsequently the union is closer.
The substance of the white columns readily separates into bundles and
fibres, but that of the gray columns falls into a granular detritus if
attempted to be teased out with needles. But after the fifth month this
is no longer so. Instead of a granular detritus there appears a network
of fine fibres and fibrils. Although the white posterior columns are
developed before the fifth month, not a single cell can be seen in
the posterior gray columns until the second half of the ninth month.
(Yet the fibres are imagined to arise in the cells!) The passage from
the granular to the fibrillar state is the same in the cell substance
and the neuroglia. The nerve-fibre, as distinguished from a naked
axis cylinder, does not appear till the fourth month. It is at first
a bipolar prolongation of the nucleus. As it elongates, the nucleus
seems to sit _on_ it, and so loosely that it is easily shifted away by
pressure on the covering glass. Finally the fibre separates entirely
from the nucleus, and _then_ begins to clothe itself with the medullary
sheath. Very curious is the observation that so long as the axis
cylinder is naked it is never varicose, but with the development of the
medulla the primitive axis becomes fluid.
[175] MAYER, _Op. cit._, 393. I cannot, however, agree with MAYER when
he says that the continuity of a nerve-fibre with a cell has _never_
been distinctly shown (p. 395); in the Invertebrata and in the Electric
fishes such a continuity is undeniable; and it has occasionally been
seen in Vertebrata.
[176] RANVIER, in the _Comptes Rendus_, 1875, Vol. LXXXI. p. 1276. This
observation throws light on the fact that cell processes are sometimes
seen entering nerve-roots (§ 124).
The very remarkable observations of Mr. F. BALFOUR, _On the Development
of the Spinal Nerves in Elasmobranch Fishes_ (_Philos. Trans._, Vol.
CLXVI. p. 1), show that the spinal root, ganglion, and nerve-trunk
arise from histological changes in a mass of cells at first all alike;
_not_ that ganglion-cells are formed and from their processes elongate
into fibres. The nerve, he says, forms a continuation of its root
rather than of its ganglion (p. 181); which accords with RANVIER’S view.
[177] In the _Handbuch der menschlichen Anatomie_ of W. KRAUSE, which
has just appeared, I am pleased to find a similar view, p. 376.
[178] On this point consult AXEL KEY and RETZIUS, in the _Archiv für
mikros. Anat._, 1873, p. 308, where the nutritive disturbance is
assigned to the fact that the lymph can no longer take its normal
course. WALLER’S observations on the degeneration of the optic nerves,
with preservation of the integrity of the retina, after division of the
nerves (_Proceedings of Royal Society_, 1856, p. 10), cannot be urged
in support of his view, because BERLIN and LEBERT’S observations are
directly contradictory of his. SAEMISCH _und_ GRAEFE, _Handbuch der
Augenheilkunde_, II. 346. It is said by KRENCHEL that if the nerves
be divided, so as to prevent disturbances in the circulation, no
peripheral degeneration takes place (cited by ENGELMANN in _Pflüger’s
Archiv_, 1875, p. 477).
[179] SCHIFF, _Lehrbuch der Physiologie_, pp. 120, 121.
[180] KÖLLIKER, _Gewebelehre_, 317. SCHWALBE, _Archiv für mikros.
Anat._, 1868, p. 51.
[181] I was first shown this in 1858 by the late Prof. HARLESS in
Munich, who at the same time showed me that the nerve thus bared of
its sheath, if left some hours in gastric juice, split up into regular
discs, like the sarcous elements of muscles.
[182] STIEDA, _Bau des centralen Nervensystem der Amphibien und
Reptilien_, 1875, p. 41.
[183] BUTZKE, in _Archiv für mikroskopische Anatomie_, Bd. III. Heft 3,
p. 596.
[184] Except in the rare cases where there is anastomosis of the
muscle-fibres; as, for example, in the heart. [According to ENGELMANN’S
remarkable researches, the muscles of the heart form a continuum,
so that irritation is propagated from one to the other: _Pflüger’s
Archiv_, 1875, p. 465. This is indubitably the case in the embryonic
heart, as ECKHARD pointed out.] This I hold to be the main cause of
its rhythmic pulsation after removal from the body. Whatever influence
the ganglia may have in exciting this pulsation, such influence would
be powerless were not the muscles so connected; as may be seen in the
other organs which are richly supplied with ganglia, yet do not move
spontaneously; and in organs (such as the ureter or the embryonic
heart, and the hearts of invertebrata) which move spontaneously, yet
have no ganglia.
[185] SCHRÖDER VAN DER KOLK, _Bau und Funktionen der Med. Spinalis_, p.
67.
[186] It is very instructive to learn that for some six months or so
the rat is quite incapable of correctly _localizing_ the pain.
[187] VULPIAN, _Leçons sur le Système Nerveux_, p. 288. The experiment
has been confirmed by ROSENTHAL, and by BIDDER (_Archiv für Anatomie_,
1865, p. 246), who first (in 1842) attempted this union of different
nerves, but arrived at negative results; as did SCHIFF (_Lehrbuch
der Physiol_, 1859, p. 134) and GLUGE _et_ THIERNESSE (_Annales des
Sciences Naturelles_, 1859, p. 181).
[188] SACHS, in the _Archiv für Anat._, 1874, pp. 195, _sq._
[189] LAPLACE, _Essai Philos. sur les Probabilités_, p. 239.
[190] The mode of termination of nerves in muscles is still a point
on which histologists disagree; probably because there is no abrupt
termination, but a blending of the one tissue with the other. In the
Tardigrades, for example, there is actually no appreciable distinction
between nerve and muscle at the point of insertion of the nerve; and
if in the higher animals there is an appreciable difference between
nerve and muscle, there is an inseparable blending of undifferentiated
substance at their point of junction. [According to ENGELMANN’S
recent researches, there seems good reason to suppose that muscles
are composed of contractile substance and a substance which is a
modification of axis-cylinder substance; the first being doubly
refracting, the second isotropic: _Pflüger’s Archiv_, 1875, p. 432.]
[191] SCHIFF, _Lehrbuch_, p. 73.
[192] FREUSBERG observed that the reflex movements in the legs of a
dog whose spine had been divided were considerably lessened after
food or drink. They fell from 95 to 46 pendulum-beats in a minute
after a _litre_ of water had been drunk. See his instructive memoir,
_Reflex-Lähmungen beim Hunde_, in _Pflüger’s Archiv_, 1874, p. 369.
[193] M. HERZEN thus describes the effects of stimulating the vagus
with varying intensities: “Si l’on se sert de l’appareil de Dubois
Raymond, on commence par appliquer une irritation tellement faible
qu’elle ne produit aucun effet; on rapproche alors peu à peu lea
deux bobines de l’appareil avec le plus grand soin, par fractions de
centimètres, par _millimètres_ s’il le faut, et l’on trouve ainsi
le degré d’irritation qui accelère les battements du cœur et qui
produit le maximum de pulsations dans l’unité de temps admise pour
l’expérience. Quand on est là il suffit _d’un millimètre_ de plus pour
faire disparaître l’augmentation, un autre millimètre peut produire une
diminution, et un _troisième_ peut arrêter le cœur complètement. En
reculant alors, en éloignant peu à peu les deux bobines, _on rètourne
à la force qui produit l’augmentation des battements_.” HERZEN,
_Expériences sur les Centres Modérateurs de l’Action Réflexe_, 1864,
p. 68. There have been serious doubts thrown on these experiments; but
several experimenters have confirmed their exactness. Quite recently
they have been confirmed by BULGHERI, _Il Morgagni_, VIII.; and by
ARLOING and TRIPIER, _Archives de Physiologie_, 1872, IV. p. 418. It
must be confessed, however, that the whole subject of the heart’s
innervation is at present very imperfectly understood.
[194] CAYRADE, _Recherches sur les Mouvements Réflexes_, 1864, p. 58.
[195] A frog’s brain is removed, and the body then suspended by the
lower jaw, the legs are allowed to dip into a slightly acidulated
liquid, the chemical action of which stimulates the skin.
[196] I saw a patient in the Berlin _Charité_ whose face and left hand
were in a constant state of convulsive twitching, but no sooner was a
scar on the left hand (where the nerve had been divided) firmly pressed
than the twitchings ceased, and _pain_ was felt; on removal of the
pressure, pain ceased and the twitchings returned.
[197] _Pflüger’s Archiv_, 1875. No one interested in the Reflex Theory
should omit a careful study of the papers by FREUSBERG and GOLTZ. I
have drawn freely from them.
[198] Sir JAMES PAGET has an interesting collection of facts which
illustrate this Law of Arrest, in his paper on “Stammering with other
Organs than those of Speech,” _British Medical Journal_, 1868, Vol. II.
p. 437, reprinted in his _Clinical Lectures and Essays_, 1875, p. 77.
[199] _Archives de Physiol._, 1868, p. 157.
[200] _West Riding Lunatic Asylum Reports_, 1874, p. 200.
[201] CLAUDE BERNARD, _Système Nerveux_, I. 383.
[202] See the excellent remarks of Dr. LAUDER BRUNTON on this point in
his paper on Inhibition in the _West Riding Lunatic Asylum Reports_,
1874, p. 180.
[203] The interesting question of interference has been experimentally
treated by WUNDT in his recently published _Mechanik der Nerven_, 1876,
and theoretically as wave-movement by MEDEM, _Grundzüge einer exakten
Psychologie_, 1876.
[204] On the distinction between first notions and theoretic
conceptions, see _Problems of Life and Mind_, Vol. II. p. 277.
[205] Not transcendental and _a priori_, as Kant teaches; but immanent
in Feeling.
[206] The reader will understand that although mechanical relations
are modes of Feeling, as all other relations are, yet their aspect
is exclusively objective, referring to objects ideally detached from
subjects.
[207] ANTOINE CROS, _Les Fonctions supérieures du Système nerveux_,
1875, p. 85.
[208] The solution offered in the present chapter was first offered
in _Problems of Life and Mind_, 1875, II. 465, _sq._ I mention
this because since the publication of that volume other writers
have expressed the same ideas, sometimes using my language and
illustrations: e. g. M. TAINE in the _Revue Philosophique_, January,
1877, art., _Les Vibrations cérébrales et la Pensée_.
[209] _Problems of Life and Mind_, Vol. II. pp. 443 and 482.
[210] “The retinal image is the last effect known of the action
of objects on us; what happens beyond the retina we know not;
our knowledge of the objective process has at present here its
limit.”--EWALD HERING, _Beiträge zur Physiologie_, 1862, p. 166. That
is to say, we have a definite translation of the process in geometric
terms as far as the retina, and thence onwards Geometry fails us, and
Neurology and Psychology are invoked.
[211] Compare PROBLEM II. Chap. IV.
[212] “Das Bewusstwerden ist nichts Anderes als ein weiter
fortgeschrittenes Erinnern oder Neuwerden des von aussen aufgenommenen
Wissens, ein innerliches Wissen dieses Wissens oder ein in sich
reflectirtes Wissen.”--JESSEN, _Versuch einer Wissenschaftlichen
Begründung der Psychologie_, 1855, p. 477.
[213] In common language a stone or a tree is said to be unconscious;
but this is an anthropomorphic extension of the term. In strictness we
should no more speak of unconsciousness outside the sphere of Sentience
than of darkness outside the sphere of Vision.
[214] The contraction may be effected in the eye out of the organism.
See p. 229. It is then no reflex.
[215] _Glasgow Medical Journal_, 1857, p. 451. See also further on,
note to p. 426.
[216] MAYER, _Die Elementarorganisation des Seelenorgans_, p. 12, is
the authority for the last statement.
[217] _Allgemeine Zeitschrift für Psychiatrie_, Bd. 31, p. 711.
[218] AUBERT, _Grundrüge der physiol. Optik_, 1876, p. 633. “The
accommodative movement of the eye is to be considered voluntary. It is
true we contract the pupil without being conscious of the contraction
of muscular fibres, _but this holds good for every voluntary movement_.
When a person raises the tone of his voice he is not conscious that
by muscular contraction he makes his chordæ vocales more tense; he
attains his object without being aware of the means by which he does
so. The same is applicable to accommodation for near objects and to
the contraction of the pupil accompanying it. The fact that _this last
is only an associated movement does not deprive it of its voluntary
character_, for there is perhaps no single muscle which can contract
entirely by itself.” DONDERS, _On the Anomalies of Accommodation_,
1864, p. 574. Professor BEER of Bonn has the rare power of contracting
or dilating the pupils of his eye at will; here ideas act as motors.
When he thinks of a very dark space the pupil dilates, when of a very
bright spot the pupil contracts. (NOBLE, _The Human Mind_, 1858, p.
124.) I believe this to be only an exaggerated form of the normal
tendency. In all of us the mechanism is so disposed that the feelings
of dilatation are associated with feelings (and consequently ideas) of
darkness; and by this association a reversal of the process obtains, so
that the idea of darkness calls up the feeling it symbolizes.
[219] SPENCER, _Principles of Psychology_, I. 499.
[220] DESCARTES expressly calls them sensitive machines. He refuses
them Thought, but neither “la vie ou le sentiment.” He adds, “Mon
opinion n’est pas que les bêtes voient comme nous lorsque nous sentons
que nous voyons.”--_Œuvres_, IV. p. 339. This example is cited by him
in proof of human automatism: “Que ce n’est point par l’entremise de
notre âme que les yeux se ferment, puisque c’est contre notre volonté,
laquelle est sa seule ou du moins sa principale action; mais c’est
à cause que la machine de notre corps est tellement composée que le
mouvement de cette main vers nos yeux excite un autre mouvement en
notre cerveau qui conduit les esprits animaux dans les muscles qui font
abaisser les paupières.” All indeed that we assign to Sensibility, he
assigns to these hypothetical animal spirits, and thence he concludes,
“Qu’il ne reste rien en nous que nous devions attribuer à notre âme
sinon nos pensées.”--_Les Passions de l’Âme_, art. 13 and 17. Comp.
_Discours de la Méthode_, partie iv.
[221] DESCARTES compares the animal mechanism to that of the grottos
and fountains at Versailles, the nerves to the water-tubes:--“Les
objets extérieurs qui par leur seul présence, agissent contre les
organes des sens, et qui par ce moyen, la déterminent à se mouvoir
en plusieurs diverses façons, selon comme les parties du cerveau
sont disposées, sont comme les étrangers, qui entrant dans quelques
unes des grottes de ces fontaines causent euxmêmes sans y penser les
mouvements qui s’y font en leur présence: car ils n’y peuvent entrer
qu’en marchant sur certains carreaux tellement disposés, que s’ils
approchent d’une Diane qui se baigne, ils la font cacher dans les
roseaux; et s’ils passent outre pour la poursuivre, ils feront venir
vers eux un Neptune qui les menacera de son trident; ou s’ils vont de
quelque autre costé, ils en feront sortir un monstre marin qui leur
vomira de l’eau contre la face.”--_Traité de l’Homme_, 1664, p. 12.
Ingenious as the comparison is, it only illustrates how machines may
be constructed to imitate animal actions. Diana always hides herself
when a certain spot is trodden upon; and Neptune always appears when
another spot is trodden upon. There is no fluctuation, no sensibility
discerning differences and determining variations. Compare the
following experiment: A monkey was placed on the table and a shrill
whistle made close to its ear: “Immediately the ear was pricked and
the animal turned with an air of intense surprise, with eyes widely
opened and pupils dilated, to the direction whence the sound proceeded.
On repetition of the experiment several times, though the pricking
of the ear and the turning of the head and eyes constantly occurred,
the look of surprise and dilatation of the pupils ceased to be
manifested.”--FERRIER, _The Functions of the Brain_, 1876, p. 171. A
mechanical monkey would always have reacted in precisely the same way
on each stimulus.
[222] Printed in the _Fortnightly Review_, November, 1874, from which
all my citations are made.
[223] SCHIFF, _Lehrbuch der Physiol._, 1858, p. 212. HERMANN,
_Physiology_, translated by GAMGEE, 1875, p. 511.
[224] Meanwhile the reader is referred to SCHRÖDER VAN DER KOLK,
_Pathologie der Geisteskrankheiten_, 1863, p. 51; or JESSEN,
_Physiologie des menschlichen Denkens_, 1872, p. 66.
[225] GRIESINGER, _Les Maladies Mentales_, p. 96.
[226] M. LUYS cites the case of a patient who conversed quite
rationally with a visitor “sans en avoir conscience, et ne se
souvenait de rien”; and he draws the extraordinary conclusion that
the conversation “s’opérait en vertu des forces réflexes.”--_Études
de Physiologie et de Pathologie Cérébrales_, 1874, p. 117. Is it
not obvious that the patient must have been conscious at the time,
though the consciousness vanished like that in a dream? The persistent
consciousness is the continuous linking on of one state with previous
states--the apperception of the past.
[227] ABERCROMBIE, _Inquiries concerning the Intellectual Powers_,
1840, p. 151. WIGAN, _The Duality of the Mind_, 1844, p. 270. DESPINE,
_La Psychologie Naturelle_, 1868, I. 54.
[228] Dr. HUGHLINGS JACKSON has quite recently cited some curious
examples in his own practice. See _West Riding Lunatic Asylum Reports
for 1875_.
[229] PROBLEMS, Vol. II. p. 478, _sq._
[230] “Le sentiment fait naître le mouvement, et le mouvement donne
naissance au sentiment.”--VAN DEEN, _Traités et Découvertes sur la
Moëlle Épinière_, 1841, p. 102.
[231] Dr. CARPENTER tells a similar story of Admiral CODRINGTON, who,
when a midshipman, could always be awakened from the profoundest
slumber if the word “signal” were uttered; whereas no other word
disturbed him.
[232] Compare an interesting personal example given by JOUFFROY, quoted
in Sir W. HAMILTON’S _Lectures_, I. 331.
[233] _Lancet_, 10th July, 1858.
[234] MARSHALL HALL in _Philos. Trans._, 1833. _Lectures on the Nervous
System and its Diseases_, 1836. _New Memoir on the Nervous System_,
1843.
[235] MÜLLER, _Physiology_, I. 721.
[236] It is better simply to remove the brain, than to remove the whole
head, which causes a serious loss of blood. An etherized animal may be
operated on with ease and accuracy. For many experiments, mere division
of the spinal cord is better than decapitation. Great variations in the
results must be expected, because the condition of the animal, its age
and sex--whether fasting or digesting--whether the season be spring or
summer--and a hundred other causes, complicate the experiment.
[237] VOLKMANN, quoted by PFLÜGER.
[238] UNZER, _The Principles of Physiology_ (translated for the
Sydenham Society), p. 235.
[239] Even so eminent an investigator as GOLTZ has fallen into this
confusion. He introduces an experiment to prove that the brainless
frog is insensible to pain by the words “when an animal, placed under
circumstances which would be very painful, makes no movement, although
quite capable of moving, the least we can say is that it is improbable
that the animal has sensation” (_Nervencentren des Frosches_, p.
127). I need not discuss the proof itself, having already done so in
_Nature_, Vol. IX. p. 84. The point to which I wish to call attention
is the confusion of insensibility in general with insensibility to pain.
[240] See DUCHENNE, _De Électrisation localisée_, p. 398. GRIESINGER
cites various examples of insane patients who have burned the flesh off
their bones while manifesting a total indifference to these injuries.
_Maladies Mentales_, p. 94. FALRET says, “Nous avons vu plusieurs
fois des aliénés s’inciser, s’amputer eux-mêmes diverses parties du
corps sans paraître ressentir aucune souffrance.” _Leçons cliniques
de Médicine Mentale_, 1854, I. 189. Patients incapable of feeling the
contact of a hot iron with their skin have felt subjective burnings in
the skin thus objectively insensible.
[241] CROS, _Les Fonctions supérieures du Syst. nerveux_, 1875, p. 27.
[242] _Virchow’s Archiv_, Bd. XXVIII. p. 30.
[243] The idea of a _fixed anatomical mechanism_ for reflexion, such
as that of an excito-motory system, is completely refuted by the fact
that the gray substance may anywhere be cut sway, and yet so long
as a small bridge of gray substance remains the stimulation will be
propagated through it. The idea of a _fixed pathway_ is also refuted by
the fact of the variations in the reflex responses, and the necessary
irradiation even for very simple reflexes. Take, for example, that of
breathing. An irritation of the bronchial filaments is transmitted by
the pneumogastric to its centre in the medulla oblongata; from this,
however, it is immediately irradiated _downwards_ to the cervical and
dorsal regions, which innervate the muscles of chest and diaphragm, and
_upwards_ to the brain, whether the stimulation awaken consciousness or
not. One may say, indeed, that inasmuch as under normal conditions the
bronchial irritation always causes a movement of a particular group of
muscles, there is to this extent a fixed pathway of discharge; but, as
I have formerly explained, this is only an expression of the particular
tension of particular centres, and is variable with that tension; the
other centres are also affected, even when they are not excited to
discharge.
[244] LALLEMAND, _Recherches sur L’Encéphale_, III. 310.
[245] _West Riding Lunatic Asylum Reports_, 1875, Vol. V. pp. 252, _sq._
[246] GALL _et_ SPURZHEIM, _Anat. et Physiol. du Système Nerveux_, I.
83.
[247] Printed in the _British and Foreign Medical Review_, Jan. 1845.
[248] GRIESINGER, _Abhandlungen_, 1872. The first volume contains a
reprint of this memoir.
[249] LANDRY, _Traité des Paralysies_, I. 55. Conf. ZIEMSSEN, _Chorea_
in the _Handbuch der speciellen Pathologie_, Bd. XII. 2, p. 408. And
LUYS, _Études de physiol. et pathol. cérébrales_, 1874, pp. 89–94.
[250] SUE, _Recherches Philosophiques sur la Vitalité et le
Galvanisme_, p. 9. He was not consistent, however, but adopted Bichat’s
opinion respecting the sensibility of the viscera, p. 68.
[251] LEGALLOIS, _Expériences sur le principe de la vie_. Published,
I conclude, in 1811; the edition I use is the one printed in the
_Encyclopédie des Sciences Medicales_, IV.
[252] WILSON PHILIP, _Experimental Inquiry into the Laws of the Vital
Functions_, pp. 209, 210.
[253] LONGET, _Traité de Physiologie_, II. 105.
[254] He cites Cuvier, Majendie, Deamoulins, and Mayo as maintaining
this error.
[255] GRAINGER, _Structure and Functions of the Spinal Cord_, p. 66.
[256] NASSE, _Unters. zur Physiologie und Pathologie_, Vol. II. Part 2.
[257] CARUS, _System der Physiologie_, III. 101.
[258] J. W. ARNOLD, _Die Lehre von der Reflex-Function_, 86.
[259] PFLÜGER, _Die sensorischen Functionen des Rückenmarks der
Wirbelthiere_.
[260] Except AUERBACH, who repeated and varied the experiments; and
FUNKE, who partially adopted the conclusions in his systematic treatise
on Physiology.
[261] SCHIFF, _Lehrbuch der Physiologie_, 208.
[262] LANDRY, _Traité des Paralysies_, 1859, maintains that the cord is
a centre of sensation, and that there is in it a faculty _analogous_
to the perception and judgment of the brain. Compare pp. 163 _et sq._
and 305. He also cites an essay by Dr. PATON of Edinburgh (_Edinburgh
Medical Journal_, 1846), in which the sensational and volitional claims
of the spinal cord are advanced.
[263] GOLTZ, _Beiträge zur Lehre von den Functionen der Nervencentren
des Froeches_, 1869.
[264] _Pflüger’s Archiv_, Bd. XIV. p. 158.
[265] See Prob. II. § 183.
[266] “Il y a donc une mémoire par le cerveau et une mémoire par
l’automate. Tous les organes ont une mémoire propre, c’est à dire _une
tendance à_ reproduire les séries d’actes qu’ils ont plusieurs fois
executés.”--GRATIOLET, _Anat. du Système Nerveux_, 1857, p. 464.
[267] To obviate misunderstanding let me say that, unless the contrary
is specified, I use the term Brain throughout this argument as
equivalent to the cerebral hemispheres, because it is in these that
sensation, volition, and consciousness are localized by the generality
of writers, many of whom, indeed, regard the cells of the gray matter
of the convolutions as the exclusive seat of these phenomena, dividing
these cells into sensational, emotional, and intellectual. There
are physiologists who extend sensation to the cerebral ganglia and
gray masses of the medulla oblongata; but the medulla spinalis is so
clearly continuous with the medulla oblongata that there is a glaring
inconsistency in excluding sensation from the one if it is accorded to
the other; and the grounds on which sensitive phenomena are admitted in
the absence of the hemispheres, force us to admit analogous phenomena
in the absence of the ganglia and medulla oblongata: in each case the
phenomena are less complex and varied as the mechanisms become less
complex.
[268] Compare LUSSANA e LEMOIGNE, _Fisiologia dei centri encefalici_,
1871, II. 239, 240, 330.
[269] See a very interesting case of this special loss of memory
in a priest who still occupied himself reading classic authors and
performing his official duties many months after an injury to the
brain. LUSSANA e LEMOIGNE, _Fisiologia dei centri encefalici_, I. 201.
[270] BOUILLAUD, _Recherches Expérimentales sur les Fonctions du
Cerveau en général_, 1830, p. 5, _sq._
[271] LONGET, _Traité de Physiologie_, II. 240.
[272] DALTON, _Human Physiology_, Philadelphia, 1859, p. 362.
[273] DALTON, p. 362.
[274] DALTON, p. 363.
[275] FLOURENS, p. 89.
[276] LEYDEN in the _Berliner klinische Wochenschrift_, 1867, No. 7.
MEISSNER, _Jahresbericht über Physiol._, 1867, p. 410.
[277] VOIT in the _Sitzungsberichte der Münchener Academie_, 1868, p.
105. Comp. also GOLTZ in _Pflüger’s Archiv_, Bd. XIV. 435.
[278] VULPIAN, _Système Nerveux_, 542–48.
[279] For other examples see GINTRAC, _Pathologie Interne_, 1868, VI.
51–57.
[280] If the water is perfectly still the fish sinks to the bottom and
remains motionless until the water be stirred. Mere _contact_ does not
suffice; there must be intermittent pulses from the moving water.
[281] LUSSANA e LEMOIGNE, _Op. cit._, I. 15.
[282] _Archives de Physiologie_, 1869, p. 539.
[283] BRÜCKE, _Physiologie_, II. p. 53. While these sheets are passing
through the press, GOLTZ has published his second series of experiments
on the brain. The following detail is a good illustration of what is
said in the text: A dog deprived of a portion of both hemispheres
displayed a marked imperfection in the execution of ordinary instincts.
Although sight was impaired he could see, and recognize men and certain
objects: the sight of a whip made him cower, but the sight of meat
did not suffice to set the feeding mechanism in action. When meat
was suspended above his head, the scent caused him to sniff about in
search, but he failed to find it, and even when he was so placed that
he could see the suspended meat, the _unusual_ impression failed to
guide him. If the meat were held towards him, or placed before him in
a dish, he took it at once--this being the customary stimulation. So
also, if the hand were held up, in the usual way when dogs are made
to leap for food, this dog sprang vigorously up and caught the food;
but he would spring up in the same way when the hand was held empty,
and continue fruitlessly springing, whereas an uninjured dog ceases to
spring when he sees the hand is empty.--_Pflüger’s Archiv_, Bd. XIV. p.
419.
[284] GRATIOLET, _Anat. Comparée du Système Nerveux_, 1857, p. 459.
[285] LUSSANA e LEMOIGNE, _Op. cit._, I. 363.
[286] _Virchow’s Archiv_, Bd. LX. pp. 130–33. Yet there are many
physiologists who persist in placing the _motorium commune_ in the
_corpora strata_! And they place the _sensorium commune_ in the optic
thalami, although, not to mention the ambiguous evidence of Pathology,
the experiments of NOTHENGEL and VEYSSIÈRE show that destruction of
the thalami does not destroy sensation. See VEYSSIÈRE, _Recherches
sur l’hémianesthésie de cause cérébrale_, 1874, pp. 83, 84. I may
observe, in passing, that the notion of the _corpora striata_ being
the necessary channel for volitional impulses, and the _optic thalami_
for reflex actions, is utterly disproved by the experimental evidence
recorded in the text, as well as in § 66.
[287] _Pflüger’s Archiv_, Bde. VIII. and IX.
Transcriber’s Notes
Punctuation, hyphenation, and spelling were made consistent when a
predominant preference was found in the original book; otherwise they
were not changed.
Simple typographical errors were corrected; unbalanced quotation
marks were remedied when the change was obvious, and otherwise left
unbalanced.
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The Table of Contents entry for Problem II, Chapter II, referenced the
wrong page; corrected here.