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http://www.archive.org/details/cu31924003039215

DYNAMIC ASPECTS

OF

NUTRITION AND HEREDITY

DYNAMIC ASPECTS

OF

NUTRITION AND HEREDITY

BY

FRANK HORRIDGE

LONDON

BAILLIERE, TINDALL AND COX
8, HENRIETTA STREET, COVENT GARDEN
1902

PREFACE

In order to explain the elementary notions on which
the theory of chemical combination is based it is
customary to borrow illustrations from physics, and
the latter science may in this sense be said to be the
foundation of the former. In medicine and physiology
physical considerations play an even more important
part, for we have not only chemical action to deal
with, but a number of rhythmical movements to take
into account. With some of these we are already
very familiar. With regard to others, however, and
especially with respect to the rhythmical movements
which take place in the nerve-cells, this is not the
case. But since we know that the nervous system
governs all movements, whether arterial, cardiac,
respiratory, intestinal, or metabolic, we have at least
a basis for conjecture, argument, and deduction.
Even though direct evidence, strictly speaking, is
unobtainable, we are still able to conceive the
character of the action in the nerve-cells to some
extent, and to draw inferences from the state and
movements of the tissues. Between the former and
the latter there must necessarily be a most intimate

vi PREFACE

degree of correspondence in regard to movement, for
in this wide world of ours there is no government
which does not rest upon a foundation of force, and
the transmission of force implies action or movement.
The reduction of chemical or physiological problems
to a physical basis is, moreover, in some respects a
process of simplification, and an endeavour to define
the character of the movements which take place in
the nerve-cells may be justified, if but partially
successful, by the hope that it may ultimately lead
to more direct and thorough methods of controlling
them.

It is surprising to observe to what extent the
physical or dynamic factor lies apparently at the root
of some of the commonest and yet most important
processes in medical practice. Indeed, to take a
striking instance, it will probably have to be acknow-
ledged, in default of any other equally credible
explanation, that the immunity conferred by vaccina-
tion is, in reality, merely the result of a dynamic im-
pression produced upon the nervous system. This will
become to some extent apparent if we fully realize
the meaning of certain characteristics of the nervous
system, and the consequences of its relations to the
whole organism.

To illustrate this, let us take a case. When some
venturesome boy imprudently takes his first plunge
in the practice of smoking by consuming one of his
father’s strong cigars, the result is usually such a
revolution in his interior as to make him regret his

PREFACE vii

temerity for some time. Had he, however, begun
with a whiff or two at a cigarette, and persevered for
a week or so in giving himself up at intervals to this
form of doubtful enjoyment, it is probable that he
would at length have been able to withstand the
effects of the stronger weed.

One fact stands out prominently in this example—
viz., that it is the influence of a first impression even
more than the actual strength of the tobacco which
disturbs the functioning of the nervous system, and
thus causes vomiting, headache, or whatever other
consequences may follow. Other cases might also be
cited to illustrate the same truth. Take, for instance,
that of the opium-eater who accustoms himself by
degrees to enormous doses, and thus, while weakening
his nervous system, nevertheless acquires for it pro-
gressively immunity from the effects which would
otherwise result therefrom.

How does the nervous system govern the meta-
-bolism of the tissues? There can, it would seem, be
only one conceivable answer to this question: the
nervous system must regulate all the various processes
connected with tissue change by virtue of the force
generated and developed in its own metabolism.
Being the most readily mobile of all the tissues, the
anabolic and katabolic changes in it give rise, we
must suppose, to a continuous series of rhythmic
-movements the influence of which is felt throughout
the body. The conditions essential to the perfect
functioning of the whole system are, therefore, that

viii PREFACE

these rhythmic movements shall possess a given
character, and that they shall be regular. These
movements, however, are easily disturbed and ren-
dered irregular. Thus, exposure of parts of the body
simultaneously to two degrees of temperature, when
sudden, is often, as we know, sufficient to upset the
rhythm of cutaneous metabolism, and produce a cold.
When bacteria in certain quantities enter the system
there is a similar disturbance of rhythm. The
nervous metabolic rhythm is one form of activity,
the vital processes going on in the bacteria constitute
another. Both the activity of the latter and their
waste products bring about a change in the en-
vironment of the nervous system, and hence -the
disturbance. The capacity of an individual to resist
the attack of an infective disease depends, one may
say, on the power of the nervous system to preserve
a certain regularity of rhythm in the presence of the
bacteria, and, above all, to preserve a rhythm in
which the excretory tendency is strongly accentuated.
One may indeed compare the cells of the nervous
system under these conditions to the members of a
small settlement on which a party of savages has
suddenly made a descent. If it be a matter of a first
and unexpected attack, the excitement and confusion
would naturally be greater than if it were a second
or third occurrence of the same kind. So it is with
the nerve-centres when bacteria of a virulent type in-
vade the system for the first time. If they become,
as they are likely to do, very excited, they lose in

PREFACE ix

part the regular and steady control which they pre-
viously exercised on the metabolism of the tissues,
including the excretory processes, and thus the
general vitality is diminished. But if after the first
period of excitement the nerve-centres regain little by
little their normal mode of functioning in the very
presence of the bacteria, or if they have done so
before in the presence of an allied but less virulent
genus, a second attack is not likely to lead to the same
degree of commotion and relaxation in the nerve-
cells, or, in-other words, to the same amount of
disturbance in the nervous metabolic rhythm. When
in vaccination the lymph is introduced into the arm,
a local disturbance of the metabolic processes takes
place. In-a few days’ time there may be swelling of
the part and other signs of inflammation. As matters
develop, especially if the case be severe, the effect
becomes more general, and slightly feverish symptoms
may be noticed. Thus both locally and as a whole
the nervous system comes under this new influence.
Its’ environment is modified, but in spite of the
baneful character of this modification it continues to
function. Within three or four weeks from the date
of vaccination all the bacteria have been worsted in
their attack upon the system. They have disappeared,
being either absorbed by leucocytes or excreted by the
usual channels. As an active force in the body they
have ceased to exist. That anything of a tangible
nature beyond the scar remains after the fourth week
is indeed highly improbable, and as time goes on the

x PREFACE

chance of any particle of the lymph being still left in
the system grows ever less. Yet the period of im-
munity is generally recognised to be from seven to
ten years. But if it is very difficult, or even impos-
sible, to rest the case for vaccination upon a material
basis, three facts in regard to it must strike one as
undeniable: firstly, that the disturbance caused by
it, lasting as it does for several days, must produce
both a marked and a specific impression on the
nervous system; secondly, that such impressions are
likely to be of a very durable kind; and thirdly, that
one such impression may modify considerably subse-
quent ones of like or allied nature.

Turning from preventive to curative medicine, we
meet with an equally striking example of the employ-
ment of measures which are in reality of an essentially
dynamic nature. For ages medicated baths of various
kinds, containing salts, sulphur, iron, and other sub-
stances, have been adopted as a means of relief in
certain pathological conditions, with results which,
leaving success in the treatment of this or that disease
out of the question, demonstrate, nevertheless, beyond
all doubt that the physiological action of these reme-
dies is not imaginary. Yet physiologists of repute
tell us unhesitatingly that not one particle of iron or
of salt or of sulphur ever enters the body through the
skin. There is no absorption of these inorganic sub-
stances, so that if they act upon the system, as we
know they do, they cannot act quantitatively, and
therefore they must act dynamically—they must, that

PREFACE xi

is to say, modify the nervous rhythm. At first sight it
may be difficult to conceive how this is brought about,
for it is very improbable that there is actual contact
between the nerve-endings and the salt or the iron
contained in the bath. But if we suppose, as we have
reason to, that a stratum of ether lies between the
nerve-endings and the chemical substance, whatever
it may be, that the nerve-endings are continually
undergoing a certain delicate vibration due to the
force generated in the nerve-cell in the process of its
metabolism, and, further, that this force causes, as it
were, waves or impulses in the stratum of ether which
dash up against the particles of salt or iron and come
back bearing the character of these substances and
thus transmitting it to the nerve-endings and through
them to the nerve-cells, then we shall understand
how the nervous rhythm may be modified and the
physiological processes depending on it altered,
although nothing whatever has been added to the
body. We can also comprehend how it is that even
an insoluble drug, such as calomel, can produce so
marked an effect, and how an insoluble preparation
of arsenic, such as dentists commonly use, causes
death in the nerve of a tooth. Transmission in such
cases is, moreover, very similar to the phenomenon
of sight if we suppose light itself to be due to ethereal
movement.

In speaking of the action of insoluble drugs and of
chemical substances held in solution in baths as being
of a dynamic nature, only a very limited portion of

xii PREFACE

the truth has, however, been stated, for there is prob-
ably no exaggeration in saying that the effects pro-
duced by all chemical compounds which act directly
on the nervous system are mainly of the same kind.
These compounds do not give rise to quantitative
changes; they do not alter the chemical composition
of the bodies of which nerve-cells are formed, although
they may contribute materials for the purpose of
building them up. A little alcohol, we may suppose,
has passed from the digestive organs into the blood,
and has finally reached a nerve-cell. Its presence
undoubtedly modifies the environment of the cell, and
influences its molecular movements, its metabolic
rhythm, in the same way as the salt or the sulphur
does that of the nerve-ending. But if the alcohol be
broken up into carbon, hydrogen and oxygen, its
specific action must at once disappear. If we were
to imagine chemical compounds as acting on the
nerve-cells quantitatively, then we should have to
conceive the tissue of the cell as being ready to absorb
at once, within certain limits, any quantity of carbon,
hydrogen, oxygen, or nitrogen which might be offered
to it, and one’s apparently well-grounded belief in the
constancy of the chemical composition of the chief
bodies contained in nervous matter would melt away.
When, therefore, we have on the one side variability
in the chemical composition of the constituents of the
nerve-cell, together with quantitative changes therein,
and on the other side constancy in the chemical com-
position of these constituents, together with dynamic

PREFACE xiii

variations in the environment of the cell as alter-
native explanations of modifications in the character
of nervous action caused by food or drugs, it is towards
the latter theory that the balance of probability
inclines. Even in the case of simple elements a
superabundance is not only sometimes useless, but
may be highly prejudicial. Phosphorus, for instance,
though a constituent of nervous matter, when given
in moderately large doses, far from contributing to
the building up of the tissues, rather increases the
katabolic tendency. The building up of our tissues
depends, one may say, less on the quantities of the
materials provided than on the play of those dynamic
influences whereby metabolism in the nervous system
and through it in the whole body is governed.

Though the chemical processes of metabolism are
both varied and complicated in the highest degree,
yet in all of them certain physical factors, such as
the simple forces of attraction and repulsion, play,
there is reason to believe, an essential part. We may
note the influence of these forces in the contraction
and expansion of vaso-motor action, we may infer it
in other instances of physiological action also, and by
keeping it always in view we may hope to penetrate
the mysteries of some problems which, when con-
sidered without making due allowance for this factor,
must remain insoluble.

In dealing with the subject of the functions of the
cerebellum too many pages have perhaps been given
up to the consideration of the anatomy of the spinal

Xiv PREFACE

cord, and the only justification for this lies in the
intimate relations which exist between the cerebral
and cerebellar systems. For this and for other short-
comings, due not only to the complicated nature of
the subject, but to personal deficiencies, I must ask
for the reader’s indulgence. To express scientific
truths with any degree of completeness is always a
very difficult matter, and this is especially the case in
the domain of physiology, where the factors with
which one has to deal vary more than in other
sciences.

February 8, 1902.

CONTENTS

CHAPTER I

PAGE
Tae Active Forces or Livinc ORGANISMS 1

CHAPTER II

Tue Sprnat CorD AND THE FUNCTIONS OF THE CERE-
BELLUM - 96

CHAPTER III

HEREDITY 157

DYNAMIC ASPECTS OF
NUTRITION AND HEREDITY

CHAPTER I
THE ACTIVE FORCES OF LIVING ORGANISMS

The invisible factor—Vortex atoms—Queries and guesses—The
omnipresence of matter—Matter is essential to conduction
—Attraction and repulsion are essential to rigidity—The
conducting medium in gravity—The vibration of atoms—
The ether permeates all matter—The reaction of atoms on
the ether as a possible cause of electrical potential—The
ether as a transmitting medium in vegetal reproduction—
Properties of the ether—Tension of the ether as a factor in
electrical conduction—Ether or light substance as the trans-
mitting medium of light—Vision an ether sense—The effect
of colours on the emotions—The two scales—The cell and the
nucleus—The cause of the nucleus in the blood corpuscles
of birds and reptiles—Nuclein, protagon and lecithin—The
relatively small amount of oxygen in the cerebral com-
pounds determines the nature of their metabolism—The
cerebral circulation—The effect of some drugs on oxidation
—Aleohol—Strychnine— Dynamic effects — Physiological
antagonism—Action and reaction—The apparent effect of
drugs on the gray matter—The nature of physiological
reaction—Some factors in metabolism—The selection of
materials by the tissues—The degree of oxidation going
on chiefly determines the nature of the compounds—The

1

2 THE ACTIVE FORCES OF LIVING ORGANISMS

negativity of oxygen—Muscular contraction is a process of
deoxidation—Conditions most favourable to anabolism—
The contractility of nerve-cells— Variations in the tension of
the ether as the cause of the current of action in a nerve-fibre
—The influence of functional activity on metabolism—The
influence of contraction and expansion on oxidation—The
nature of the nervous impulse—Electrical vibration is
always connected with chemical or with molecular vibra-
tion—The three elements—Electrical phenomena—Elec-
tricity intensifies the effect of the conditions under which it
is administered—Electricity as an almost neutral agency—
The effects of high altitudes—Mountain sickness—The chief
points—The importance of the nervous factor—The relative
diminution of carbonic acid and oxygen in the blood—The
effect of variations in the relative amount of these gases—
Effects of diminished atmospheric pressure—Diminution
of chemical intensity in high altitudes—Observations on
individuals in the Alps—Experiment to demonstrate the
effect of carbonic acid on the respiratory movements—The
composition of the blood in high altitudes—The influence
of a place may be transmitted through the ether—Some
results of massage—Contractility—The influence of pre-
existing conditions— Application of the theory of the ethereal
nature of electricity to physiology—Views of French physio-
logists on electro-motory action—The transport of atoms in
an electrical cell and in the body—Absorption in the ameba
—The concatenation of automatic actions and reactions in
digestion—Chemical action as a cause of nervous impulses
—Secretory or chemico-sensory nerves in the submaxillary
gland—Direct stimulation of the chemical processes—Rela-
tive independence of electro-chemical action and nervous
action in metabolism—Difference between secretory action
in the submaxillary gland and in the stomach—All nerves
and nerve-cells are concerned in chemical action—Heat and
cold in their relation to nervous action and metabolism.

Marrer and force are the finite elements into which
any substance, whatsoever be its nature, is divisible.
Hitherto in biological science attention has been so

THE ACTIVE FORCES OF LIVING ORGANISMS 3

closely riveted on the former that the latter has never
really emerged from the obscurity of the background.
The reason of this is not far to seek. Force is the
one factor in the calculations of modern research
which escapes our ken, the impalpable element in all
our problems, the unknown quantity, the eternal X in
the algebra of science. It appears in many guises—
as wind, water, steam, light, heat, chemical energy,
molecular vibration, sound, magnetism, nervous im-
pulses, and electricity, now gathering its units into a
single wave, now scattering them over a broad expanse,
sometimes storing itself up with slow and steady pro-
gress, anon bursting forth into rapid and violent
shocks, transforming itself with surprising sudden-
ness, according to the conditions of the media through
which it passes, always in a sense active, always in-
visible, and yet never really lost. Assuredly what
little we know of such a phenomenon is sufficient to
make us attribute to it the greatest, most extensive,
most unforeseen powers, and to lead us to suspect its
action in those mysterious physiological processes
which without it are, and must, remain inscrutable,
impenetrable riddles. In an investigation such as
that which lies before us we shall see it in many
phases, carving, moulding matter, and being in turn
acted on, directed, modified.

There is no more interesting theory with respect
to the constitution of matter than that of Sir W.
Thomson, which consists in regarding atoms as
little masses of ether always in motion, as differing,

1—2

The invis-
ible factor.

4 THE ACTIVE FORCES OF LIVING ORGANISMS

in fact, from the rest of the ether only in the modes of
motion to which they are subjected. Such whirling
portions possess rigidity through the very fact of
their motion,* so that we may say with truth that
force, which is merely another name for the motion of
matter, is the very essence of matter. It is the cause
and origin of all material substances.

This idea has been rendered more easily compre-
hensible by the observation of vortex rings. These
are produced by giving at a certain moment to every
atom in a plane disc of a fluid a velocity which should
be graduated according to its distance from the edge
of the disc.t If you take a box, over one side of
which a piece of stuff is tightly stretched, whilst in
the opposite side a circular hole is cut, and, after
filling the box with smoke or other visible fumes, tap
smartly on the covered side, a vortex ring may be
clearly observed sailing through the air.{ Its pro-
perties are interesting. In the first place, it has
become differentiated from the rest of the air by the
application of external force of which it has become
the embodiment. It has remarkable stability; the
core is elastic and possesses rigidity. When one

Vortex vortex ring impinges on another they are deflected
atoms. in their course, and vibration occurs. It is on some-
what similar lines that atoms are supposed to be
formed, and hence they are called vortex atoms.
* Lodge, ‘Modern Views of Electricity,’ p. 416.

+ Lodge, loc. cit., p. 412.
t Wurtz, ‘The Atomic Theory,’ pp. 326-328.

THE ACTIVE FORCES OF LIVING ORGANISMS 5

The bare statement of such a theory as that of Basses
vortex atoms brings a host of questions to one’s lips. guesses.
If this be true of the atom, is it not true of the world
also? Is nota world a collection of atoms, just as a
crowd is a collection of individuals? and does not a
crowd behave in a general way, though perhaps with
greater intensity, as a single individual does? If
atoms are mere collections of ether, is their perma-
nence relative or absolute? Are we right in supposing
them to be eternal, to have had no beginning and to
have no end? Or, on the other hand, are they the
result of forces in the ether itself—forces acting
within a given space, it may be, for trillions of years,
and yet not eternal in that space? Can we attribute
eternity to atoms and not to worlds? Can we take
such a stand positively, remembering that vortex
movement is but one phase of motion or force? If
the force implied in the vortex movement of atoms
be really and solely intrinsic, how are we to explain
the fact that all ether does not resolve itself into
atoms? May we not conclude that in every sufficiently
great volume of ether there is a tendency towards the
formation of a focus due to more or less equal pressure
on all sides? May we not suppose that the rotational
movements of stars and atoms alike are the result, in
the first instance, of pressure of this kind? Motion,
within certain limits, is, we may assume, the property
of infinitely divided matter, such as the ether. All
that is wanted, therefore, is a certain condition of
things which shall give that motion direction. The

The omni
presence
of matter.

6 THE ACTIVE FORCES OF LIVING ORGANISMS

celestial bodies may be looked on as foci of ethereal
force, each one of them reacting to some extent upon
those nearest to it. If we adopt this view, do we not
obtain an inkling of the causes which have determined
the existence of so great a variety of atoms—a variety
which is reproduced in so striking a manner in the
most distant corners of the heavens? Deny these
causes, and, since hydrogen is known to exist in the
furthest nebule, one must suppose that all matter
was once united in one huge mass, a conception
appalling to the imagination of the veriest Atlas
amongst philosophers. Moreover, if we regard each
kind of atom as a particular degree of force embodied
in ether, we can imagine to some extent how its vibra-
tions in chemical action give rise to nervous and other
forms of force.

For a long time a belief has been entertained that
beyond the limits of our own atmosphere nothing
remained but empty space. But of recent years this
opinion has been frequently called in question, and
many of our foremost thinkers have now become so
materialistic in their view of things as to conceive the
hitherto inconceivable notion that ether itself is a
form of matter, that it is to be found everywhere, and
that empty space is simply non-existent*—at least,
so far as the universe is concerned. What there may
be beyond the universe, supposing it to embrace all
that we are ever likely to see with the most powerful
telescope, need not trouble us very much. LEven

* Lodge, loc, cit., p. 879.

THE ACTIVE FORCES OF LIVING ORGANISMS 7

those who for the sake of a theory would push deduc-
tive investigation forward into regions so distant will
do well to remember that the absence of tangible
signs of matter does not justify the assumption of
its non-existence. 4lts infinite divisibility and omni-
presence are, indeed, conceptions which we can no
longer afford to disregard.

The view that ether is really matter in the finest
state of division appears to be confirmed by certain
simple reflections. Matter in some form is either
absolutely necessary for the conduction of light and
heat or it is not. If we adopt the view that it is
essential, we must conclude that all forms of force
constitute a jostling of infinitely small particles, for
we can have no conception of force otherwise than as
matter in motion. We shall then be led to suppose
that both heat and light are merely modes of motion
communicated to the free ether, and from it to the
bound ether of atoms and of matter in general. But
electricity has within recent years been found to bear a
very close relationship to light, which is, indeed, held
to be an electrical phenomenon.* There appears,

* Lodge, loc. cit., p. 877: ‘The main proof of the electro-
magnetic theory of light is this. The rate at which light travels
has been measured many times, and is pretty well known.
The rate at which an electro-magnetic wave disturbance would
travel, if such could be generated, can be also determined by

calculation from electrical measurements. The two velocities

agree exactly.’

[If the ether be the common medium by which the light
wave is, and the electro-magnetc iwave might be, transmitted,
the equality of velocity is, to some extent, explained. The fact

Matter is
essential
to conduc-
tion.

8 THE ACTIVE FORCES OF LIVING ORGANISMS

therefore, to be some reason for supposing electricity
also to be, like heat and light, a mode of motion of
ether.

This way of looking at things has, moreover, the
advantage that it enables us to understand why, as is
so often the case, one form of force is suddenly
transformed into or gives rise to another—heat to
light, chemical action to heat and electricity. If, on
the other hand, we put aside the theory that force is
always a mode of motion of matter, it will be seen
at once in what an argumentative quagmire we are
landed, for we should then be obliged to imagine it
as existing per se, and apart from matter, which
means that it would be produced out of nothing.
Such a conception, to say the least of it, transcends
the powers of human comprehension. Nevertheless,
the idea of empty space is so ingrained in our nature,
owing to the limited range of our senses, that it will
be long before it is completely banished from our
minds, as banished it must one day be, if we are to
form correct views of the universe.

Once having subscribed to the theory that atoms
are little whirling masses of ether, one is naturally
inclined to go a step further, and to draw certain
deductions. The infinitesimal particles of which we
must suppose each atom to be composed are, so long

that electricity in its usual form travels still faster may perhaps
be accounted for either by the absence of wave movement or
by other conditions affecting the medium of which we are
ignorant.—F, H.]

THE ACTIVE FORCES OF LIVING ORGANISMS 9

as their corporate existence lasts, all subjected to a
common form of motion. This motion is the cause

of or constitutes the rigidity which is the essence of

the atomic form. Rigidity implies two things: it ue
implies a certain degree of attractive power and a Sion are

certain degree of repulsive power. Chemistry teaches to rigidity.
us that these powers exist—that they are, in fact, the
basis of all the interchanges comprised under the
term ‘ chemical action.’ Now, if we remember ‘ that
every substance in the universe attracts every other
substance with a force jointly proportional to the
mass of the attracting and of the attracted body,
and varying inversely as the square of the distance,’*
we pass at a single stride from the atomic theory :to
the law of gravity, from the atom to the world or
collection of atoms.

Since, however, we have already come to the con- a
clusion that no conduction of force can take place medium in
save through the medium of matter, we must suppose ene
that, when an apple falls to the ground, either force
has been transmitted to it from the earth through the
medium of the air or the ether, or that it has come
under the influence of force proceeding from the
ultra-mundane ether, and affecting it, the earth, and
all that appertains to it in common. But in the
attraction exerted by one heavenly body on another
the atmospheric air may be left out of account, and
the ether remains as the sole medium for the trans-

mission of attractive force.
* Balfour Stewart, ‘ Physics,’ p. 44,

lo THE ACTIVE FORCES OF LIVING ORGANISMS

Tt will, of course, be borne in mind that the pre-
dominance of attractive power over repulsive power is
an essential condition of the existence of atoms. Were
the latter greater than the former vortex, motion
could no longer continue, and with its cessation the
rigidity peculiar to matter would disappear, and the

ane vibra- bound ether of the atom would become free. We

atoms. may perhaps suppose that when chemical action
takes place, as it always does, owing to some
external force, such as light or heat or electricity—
that is to say, to a movement of some kind of the
ether—the perfect vortex motion is momentarily
modified, that there is, as it were, a slight tendency
on the part of the bound ether of the atoms to become
free, to vibrate in unison with the disturbed ether sur-
rounding them, and, reacting on it, to communicate
to it a portion of the force which in the quiescent
state is more entirely internal.

Theether Not only do physicists look upon ether as filling

Ei mation, all space between our earth and the other heavenly
bodies, but they also suppose it to permeate all
matter surrounding atoms and filling up whatever
vacuum would otherwise be left between them.

There This view is of interest for many reasons, and

action of 2 :
atomson amongst others because it seems to suggest a partial

the ether : : P i ‘
asapos- @XPlanation of the electrical differences which exist
sible cause : * “
ofelec. between various substances; for, if we consider
Sepeatal electricity to be a mode of motion of the ether, we
may assume that all atoms when excited by a vibra-

tion of the latter would not react with the same

THE ACTIVE FORCES OF LIVING ORGANISMS 11

degree of intensity, and one might speak of those
which react with greater vigour as being of higher
electrical potential than those whose reaction on the
ether was weaker, or was attractive rather than re-
pulsive. When a current of electricity is passed
through certain substances so as to set up chemical
action, it is evident that the attractive or repulsive
properties of the atoms so affected are brought into
play. Similarly, when the molecules of any sub-
stance, such as sealing-wax, are excited by rubbing, it
possesses attractive or repulsive power, according to
the stuff or substance with which it is rubbed and
with which it is brought into relation. The pheno-
menon of gravity tends to show that the attractive
power of matter may be communicated to the ether,
and through the ether to other bodies. Matter in
that case is in its normal or quiescent state, and it
seems natural to suppose that when it is excited, as it
is by rubbing, its effect upon the ether would be far
greater. If, therefore, two substances be rubbed
together, we might suppose that each would com-
municate to the ether permeating the other something
of the character of its atoms or molecules. Some-
thing of this kind seems to occur when a pith-ball is
touched by excited glass or excited sealing-wax. The
ether permeating and surrounding the ball may be
then supposed to act as a medium of attraction or
repulsion, according as the sum of the atomic and
molecular influences brought to bear on it agrees or
disagrees with the sum of the influences proceeding

The ether
as a trans-
mitting

medium in

vegetal
reproduc-
tion.

Properties
of the
ether.

12 THE ACTIVE FORCES OF LIVING ORGANISMS

from the other substance brought within range. If
this be true, not only does the dual fluid theory dis-
appear, but we obtain in addition a clue to the
mysterious processes of natural reproduction ; for if
the ether is able to transmit influences from such a
substance as a piece of excited sealing-wax to a pith-
ball, and, so to speak, to impress to some extent its
character upon it, we are justified in supposing the
same medium might carry an influence or impulses
from the excited root or the excited leaf of a plant to
the equally excited seed. Further, the potential or
latent force stored in the latter supplemented from
without gives to the seedling its special form and
character. If in connection with the subject of heredity
transmission there be one truth deserving attention
more than another, it is that force is always the mould-
ing agent of matter, or, in other words, that the form
of matter can only be modified by matter in motion.
In speaking of anything of so impalpable a nature
as the ether, there is always some risk of attributing
to it, for the purposes of any argument, characteristics
which it does not really possess. At the same time,
however, our knowledge of it may perhaps be in-
creased by considering it in its relation to certain
natural phenomena, and by carefully examining and
comparing the consequences of our general concep-
tions of it. Thus, it is frequently said that the ether
constitutes an all-pervading, indivisible medium.
This latter property has been recently cited as a proof
that the ether is not the medium by which waves of

THE ACTIVE FORCES OF LIVING ORGANISMS 13

light are transmitted, for it has been argued that an
absolutely indivisible medium cannot be thrown into
waves. The weakness of this argument seems to lie
to some extent in the fact that use is made of words
generally employed to represent finite ideas to describe
that which is essentially infinite. In the first place,
it is evident that the ether is divisible by the mole-
cules and atoms which move and have their being in
it; but, on the other hand, it will be seen that a
medium, consisting of matter in a state of infinite
division, must of necessity be in a certain sense indi-
visible. It is a case of les extrdmes se touchent. The
air around us may in a more limited manner be said
to be at one and the same time both infinitely divided
and indivisible. We shall probably obtain a more
correct idea of the ether if we attribute to it in a still
higher degree many of the properties of air with which
we are familiar. Amongst these we may mention two
which are of importance, the first being the property
of being thrown into waves, and the second that of
conducting impressions from one substance or collec-
tion of molecules to another. That the ether possesses
this latter property in a very high degree we may
believe ; for the more matter is divided, the less do
the particles of which it is composed possess any
individuality, and the more readily do they obey any

impulse they may receive.

There is a second property of the ether which may Tension of
: js : eetheras
be said to be evolved out of its all-pervading nature a, factor ia
‘ se a : electrical
and its conductivity, and this is tension. condue-
tion,

Ether or
light sub-
stance as
the trans-
mitting
medium of
light.

14 THE ACTIVE FORCES OF LIVING ORGANISMS

The air, to return again to the more familiar
example, is always in a state of tension, irrespective
of its weight. If you take a vessel from which the
air has been withdrawn and make an opening in the
bottom, it will naturally fill again as rapidly as if
the aperture had been in the top. But the tension
of the ether is far greater than that of our atmosphere.
Now, if we suppose a number of molecules or of
molecules and atoms to be vibrating at a given point
A—to be hammering, that is to say, the ether—and
another lot to be hammering it, though in a different
manner, at a given point B, let us say, it is evident
that when the general tension of the ether is taken
into consideration, conditions favourable to an inter-
change or discharge of impulses might be said to exist.
Certain media—such, for instance, as a copper wire
—may be used to isolate a stratum of the ether
between any two points, and thus to render com-
munication the more easy. When, however, a suit-
able apparatus is raised to a certain height above the
ground, so as to be removed in all probability from
the ethereal influence of the earth and objects on
it, even the use of a connecting wire, as Marconi’s
experiments have shown, is unnecessary.

Those who refuse to adopt the view that light is
transmitted by means of the ether are, neverthe-
less, obliged to base their conception of it on the
existence of a second medium, called by them light
substance, which in its chief properties of divisibility
and ubiquity so closely corresponds to one’s notions

THE ACTIVE FORCES OF LIVING ORGANISMS 15

of the ether as to be, practically speaking, inseparable
from it.

Although what we know of the physiological action Vision an
of light does not appear to furnish us with a clue to eee
its origin, yet there are certain points in connection
with it which are of interest. If, for instance, we
look upon the ether as the medium by which light
waves strike the eye, then we must perforce recognise
it as playing the part of an initiating agency in one
of the most important of all physiological processes.
Further, if the ethereal movements coming from
without start physiological action, it seems impossible
to withstand the conclusion that the ether within the
body may also in a very marked degree contribute
to, if not originate, processes of a similar nature.

It has often been remarked that certain colours The eter!
give rise to different emotional states. The colour on the
red is often spoken of as a warm tone, and, when alas
vivid, causes in us what one may term an emotional
glow. In the turkey-cock and bull this effect is much
more pronounced, and assumes the character of
furious rage. Yellow brightens the feelings, dazzling
on the whole rather than exciting. Green awakens
emotions which approach those caused by yellow,:and
yet are more subdued; it cheers and soothes at the
same time, the effect varying as it inclines towards
yellow or blue. The latter colour has a distinctly
tranquillizing effect, and the results obtained by those
who have had practical experience in the treatment
of disease by light baths tends to corroborate this

The two
scales.

The cell
and the
nucleus.

16 THE ACTIVE FORCES OF LIVING ORGANISMS

statement, affording proof also that the red rays are
the most exciting. Violet is, as is well known, the
colour used in royal funeral ceremonies, and is
decidedly calming. Thus, we have, as it were, a
scale of colour and a scale of emotions, and it will be
seen that in discussing them we have passed from
one end of the spectrum to the other in the order in
which the various kinds of light are arranged accord-
ing to the length of their waves. One cannot believe
this to be mere hazard, and this agreement between
the two scales becomes of greater interest when we
reflect that the character of our emotions is probably
dependent on the mode of vibration of the molecules
of the nerve-cells. The movements of the latter
depend directly, it is true, on the intensity of certain
oxidation processes in the retina, but these in turn
are doubtless influenced in varying degrees by the
shade of the light by which they are started.

In order to obtain a comprehensive view of many
of the most mysterious phenomena of life, it is very
important to consider the nature of the nuclei of cells.
Within recent years it has been said that every cell
either has, or at some time had, a nucleus. This
statement has been put forward rather as an article
of belief than as a fact due to actual knowledge. In
certain unicellular organisms—such, for instance, as
the yeast plant—the existence of a nucleus has
frequently been doubted, but those who hold to the
opinion of its omnipresence allege that the particles
of which it is composed must become disassociated

THE ACTIVE FORCES OF LIVING ORGANISMS 17

during or previous to the act of observation. This
reasoning might possibly apply to some cells, but it
could not be advanced to explain the lack of a nucleus
in the red corpuscles of the blood of mammals. The
only way out of the difficulty would seem to lie in the
contention that the red corpuscles are not cells in the
proper sense of the term. But though this may be
true, what are we to say of the red corpuscles of the
lower animals, which are distinctly nucleated ? How
can we explain this peculiarity, bearing in mind that
a nucleus is recognised by all observers to be the most
essential part of a cell? Are we to classify the one
set of corpuscles as cells and not the other ?*
One might at first sight be inclined to connect the The cause
presence or absence of a nucleus with the rate of nucleus in

the blood

tissue-change, since very many of the creatures pos- sorpasalca
ras

sessing nucleated corpuscles belong to the cold-blooded and rep-
class, whose vital functions are strikingly slow. Thus, sis

a salamander can live without food for six months; a

toad for two, and fresh-water polypi for five or ten

years ; whilst a snail, after six weeks of abstinence,

* Quain’s ‘Anatomy,’ p. 29: ‘The affirmation of Bottscher
that a nucleus is present in the mammalian red blood corpuscle
rests entirely upon erroneous methods of preparation. That of
Stricker (which is a revival of the older opinions of Wharton
Jones, and of Busk and Huxley), that the mammalian red cor-
puscle is, morphologically, a nucleus with an imperceptible
amount of enveloping cell-substance, is quite distinct from
Bottscher’s view, and has certain considerations to recommend
it, but is supported at present upon an insufficient basis of fact,
and is opposed, moreover, to recent observations upon the de-
velopment of the red disc.’

2

18 THE ACTIVE FORCES OF LIVING ORGANISMS

only loses about an eleventh part of its weight.* But,
on the other hand, birds possess nucleated corpuscles,
and yet they of all animals are the first to suffer from
want of food, whilst their respiration is of a very
intense nature. One day’s total abstinence, it is
affirmed, will kill a sparrow, three days a thrush,
the respiratory intensity, as measured by the relative
quantities of oxygen absorbed and carbonic acid and
nitrogen exhaled, being seven times greater in birds
than in mammifers, whilst that of the latter is ten
times that of reptiles. It does not, therefore, seem
to be possible to establish any connection between the
presence of the nucleus and the rate of activity of the
vital processes. On the other hand, however, there
seem to be some reasons for supposing the develop-
ment of the nucleus to be inversely proportional to
that of the nervous system. The nucleus is by
common consent a centre of vitality for the cell. If
we estimate the vitality of the tissues in the lower
animals by the readiness with which portions separated
from the organism reunite with it—as, for instance,
in the case of an earthworm, or by the long-continued
twitchings to be observed in a spider’s legs when cut
off from the body—we shall be inclined to conclude
that life in these and similar types is less centralized
than is the case with mammifers in general. A
parallel to these conditions may be found in institu-
tions of human origin ; for as the central authority in
any country increases, the power of the individual as
* Letourneau, ‘ Biology ’ (trans.), p. 147.

THE ACTIVE FORCES OF LIVING ORGANISMS 19

steadily diminishes. These considerations do not, it
is true, go to the root of the matter, for no definite
statement can be made until the conditions under
which the red corpuscles are manufactured are more
clearly known.

The analysis of the substance of the nuclei of cells Nuclein,
by various observers shows that nuclein, its chief and
z : Z lecithin.
ingredient, contains the elements carbon, hydrogen,
nitrogen, phosphorus, and oxygen. The results ob-
tained on different occasions do not, unfortunately,
allow the proportion in which they occur to be fixed
with absolute certainty, but the following formula*
may be taken as showing approximately the amount
of each : CagHygNoPsOy0.

It is interesting to compare this formula with those
of two of the chief constituents of the brain,t viz.,
protagon (Cig.H,,,N,PO,,) and lecithin (C,,H,,NPO,).
In the first place, we see that, though these three
substances are built up on somewhat similar lines,
since they each contain nearly twice as much hydro-
gen, as carbon, and small amounts of nitrogen and
phosphorus, yet nuclein contains a relatively con-
siderable amount of oxygen. This fact points to the
conclusion that the amount of oxygen present, or, at
any rate, the degree of oxidation going on during its
formation, is greater than is the case when in their
respective localities of origin protagon and lecithin
are formed. Lecithin, it is true, is a substance which

* Foster’s ‘Physiology,’ Appendix, Sheridan Lea, p. 88.

+ Ibid., pp. 184-187.
2—2

20 THE ACTIVE FORCES OF LIVING ORGANISMS

is found in many parts of the body, amongst others
in muscular tissue and in red blood corpuscles, and
its presence in these regions may seem to contradict
that which has just been said. But it must be borne
in mind that the formation of any substance, and its
appearance in a given locality, may be totally separate
events, and it ig very probable that those localities
in which red blood corpuscles are formed—such, for
instance, as the cancellous tissue of bone—are not
seats of active but of restricted oxidation. The supply
of blood in the red marrow is abundant, it is true,
but the flow of blood is slow, and there is very little
movement of any other kind. If we suppose lecithin
to be formed in such a region, the supply of phos-
phates in the bone itself would seem to be a not im-
probable source whence the minute quantities of phos-
phorus required are drawn. Whatever be the truth
in regard to this point, it is evident that, when such
substances as lecithin and protagon are formed, which
are, comparatively speaking, poor in oxygen, this gas
must in some way be kept in the background.

The composition of the three bodies above men-
tioned is such that, if broken up, the amounts of each
of the elements carbon and hydrogen would be able
to combine separately with, or absorb more—and in
the case of the cerebral compounds very much more
—than, the quantity of oxygen present. It is a very
debatable point whether, in addition, the presence of
phosphorus renders these compounds more than
usually liable to become oxidized. With respect to

THE ACTIVE FORCES OF LIVING ORGANISMS 21

the behaviour of this element in the animal economy
opinions differ greatly. Some look upon its presence
in the brain and elsewhere as without any special
meaning; others are disposed to regard it as a factor
of importance in vital processes. That it is a very
active element is undeniable, and although in certain
insoluble or slightly soluble compounds this activity
may disappear, yet there is no reason to suppose
that it plays a quiescent or secondary part in cerebral
matter, in the nuclei of cells and in the yolk of egg.
These are at all times centres of great activity, and it
seems improbable that the element phosphorus, which
in the free state has so great an affinity for oxygen,
should remain inactive at such moments, or even rela-
tively so. Some authorities hold that, after severe
mental exertion, the amount of phosphates in the
urine is increased. By others this is denied. Although
on general grounds one may suppose the former to
be in the right on this point, yet, if the amount of
phosphorus liberated during cerebral action is at all
in proportion to the quantity of carbonic acid formed,
any increase of the former due, as there is reason to
suppose, to the breaking down of lecithin* would be
very slight. Sometimes, however, when abnormally
large quantities of phosphates are present in the
urine, it is not improbable that this is due to a greatly
relaxed condition of the tissues in general and of the
bloodvessels to the nerve centres, whereby metabolism

* Foster, loc. cit., p. 651.

The rela-
tively
small
amount of
oxygen in
the cere-
bral com-
pounds de-
termines
the nature
of their
metabo-
lism.

22 THE ACTIVE FORCES OF LIVING ORGANISMS

is carried on under conditions of excessive oxidation
and of loss.

In respect to the nature of metabolism in the cere-
bral and other nerve centres, one feature deserves
special attention. The composition of the chief com-
pounds which go to make up the brain and spinal
cord, or those parts more properly called nervous
matter—of lecithin, that is to say, and protagon—is
such that, however rapid metabolism may be, the
actual degree of oxidation in a healthy subject is very
limited. As already remarked, the amount of oxygen
compared to the other elements which they contain
is, indeed, so small that they are incapable of absorb-
ing much of that gas when forming, or of producing
much carbonic acid when breaking down. When the
venous blood from the brain is compared with that
proceeding from a muscle, it is found to contain much
less carbonic acid. Both the white matter of the
brain and muscle contain a large proportion of water,
the amount being 70 per cent. in the former and
75 per cent. in the latter. But the chief constituents
of cerebral matter, such as protagon, cerebrin, and
lecithin, contain more carbon in proportion to the
amount of oxygen which enters into their composition
than does the proteid of muscle; they also contain
vastly more hydrogen, and, excluding the nuclei of
muscular tissue, more phosphorus, though probably
less nitrogen. The amount of oxygen in proportion
to the carbon present being more in muscle than in
the substances just mentioned, it is natural that the

THE ACTIVE FORCES OF LIVING ORGANISMS 23

quantity of carbonic acid given off in metabolism
should be greater—in other words, oxidation in the
muscles, which compose so large a portion of the
entire organism, is more intense than in the brain
and spinal cord, or, to put it in another way, the
nervous system compared to the muscular system,
and in all probability compared to the viscera also,
is an area of restricted or limited oxidation. On the
other hand, if we are justified in estimating the readi-
ness to oxidize by the relative amounts of oxidizable
elements, such as carbon, hydrogen, and phosphorus,
and by the degree in which they are already oxidized
in muscle and in brain matter, then it is the latter
which appears to have the keener appetite.

When it is remembered that the nature of the meta-
bolism in the nervous system probably governs that
taking place in the tissues, the necessity of ascertain-
ing the degree of each, and the relations which they
bear to one another, will at once be evident. The
belief that one cannot oxidize too much is, indeed, a
very common one nowadays, but in view of the facts
already mentioned it is one which requires a consider-
able amount of qualification, especially in those cases
in which the bloodvessels to the nerve centres, either
through hereditary or other causes, expand and con-
tract too freely upon stimulation. Stoking is doubt-
less all very well, but it is necessary not to forget the
damper ; and whilst we possess a multitude of methods
of stimulating oxidation, we have none by means of
which it can be regulated.

The cere-
bral circu-
lation.

24 THE ACTIVE FORCES OF LIVING ORGANISMS

Tf we take the brain as a whole, one of the most
remarkable points in connection with it is the small
amount of the blood-supply. The actual amount of
blood in the brain of a rabbit is hardly more than
1 per cent. of that in the whole body.* It is but
one-half of that which might be extracted from the
kidneys, whilst in the liver there is more than twice
as much again.t The cortical supply is, however,
probably more abundant than that to the white
matter, and since the cortex in the rabbit is but ill
developed, the low percentage above-mentioned may
to some extent be accounted for in this way. In man
we may suppose that the quantity of blood flowing to
the gray matter bears a slightly higher proportion to
the rest, but at the same time it is none the less true
that the quantity of oxygen absorbed and of carbonic
acid formed—or, in other words, the intensity of oxida-
tion under normal conditions of activity—is governed
by the chemical composition of the substance of the
brain. When allowance, therefore, has been made
for the difference in the development of the cortex in
the rabbit and in man, there are still reasons for
regarding the nervous system as a whole as an area
of relatively limited oxidation. Cerebral circulation
is, indeed, slackened and restricted at the very outset
by the extreme sinuosity of the arteries. It is said
that this is in order to prevent any too sudden or
violent flow of blood to the cerebral centres, the con-
sequence of which might be dangerous. But this is

* Foster, loc. cit., p. 1239. + Ibid., p. 1239.

THE ACTIVE FORCES OF LIVING ORGANISMS 25

evidently the effect and not the cause of this sinu-
osity, which can be best explained by supposing a
naturally sluggish flow and certain conditions of
physical resistance to have existed in the course of
development. Moreover, the brain of all the viscera
is that which undergoes least massage through bodily
movements, and the absence of this stimulus may
be looked on as one of the causes of the restricted
character of oxidation in nerve centres. In all meta-
bolism there are two principal factors, one of which
is the blood-supply and its state of oxidation, whilst
the other is movement in the tissue, which is both
molecular and atomic.

The action of certain drugs upon the nerve centres
illustrates in a curious manner the delicate nature of
the mechanism, the key to which is oxidation in a
given. degree. The primary effect of a moderate dose
of alcohol is to quicken the heart’s action, to increase
indirectly the contractility of the muscles, and to

* Tt will be borne in mind that the effect of a drug on the
substance of nerve-cells, or on protoplasm in general, and its
effect, especially its primary effect, or its effect in small doses
on the organism, are often really opposed to one another.
Drugs which diminish oxidation in protoplasm, considered per
se by constricting it, cause at first an increase of contractility
in the heart and vascular system, and hence indirectly, and
within certain limits, produce an augmentation of oxidation.
At the same time, the ultimate effect of such drugs—that is to
say, the reaction of the system—after they have ceased to act, is
in general opposed not to the indirect effect they produce, but
to the direct effect on protoplasm. It is for that reason that,
in the remarks which follow, attention has been chiefly directed
to the latter.

The effect
of some
drugs on
oxida-
tion*
alcohol.

26 THE ACTIVE FORCES OF LIVING ORGANISMS

stimulate the nerve centres.* If the dose be aug-
mented, a very marked slackening of the vital pro-
cesses occurs. The general consequence of large
amounts of alcohol is said to be to arrest oxidation
by imprisoning the oxygen in the blood corpuscles,
thus impeding the transfer of it to the tissues.+ Just
as sleep produces a decrease of oxidation, so con-
versely a diminution of oxidation when caused by
alcohol leads to drowsiness and sleep. Alcohol itself
is a product of what one may term incomplete oxida-
tion, for when more’ completely oxidized it- gives rise
to ethyl aldehyde and water, to acetic acid and water,
or to carbonic acid and water. Until it combines
with what oxygen it can seize, it appears to produce a
chemico-dynamic effect—it seems to strike a note of
incomplete oxidation, of the state, that is to say, in
which it was produced. It is not impossible that its
stimulative effect in the first instance is due, not, as
has been supposed, to an increase of oxidation, but to
a slight decrease. A change in the degree of oxida-
tion is probably always a stimulus to nervous action,
for the molecules of the nerve-cells may be supposed
to vibrate in a different manner, the rearrangement
which they undergo constituting excitation to increased
movement. Thata diminution of oxidation is attended
by increased nervous excitability is conclusively proved
by the phenomena of asphyxia, in the first stage of
which the heart’s action is increased.

* Mitchell Bruce, ‘Materia Medica and Therapeutics,’ pp.
155, 156.
+ Ibid., p. 155.

THE ACTIVE FORCES OF LIVING ORGANISMS 27

Another important drug which probably acts by ee
diminishing oxidation, not perhaps in the tissues
generally, but in the nerve cells, is strychnine.* A
fact of considerable interest in connection with this
alkaloid is that it is produced in the nut called nux
vomica by an arrest of the oxidizing processes which
are going on in it,t so that when it acts upon man it
may be said to transfer the chemico-dynamic state
directly from the vegetal to the animal kingdom, and
in this state it is the degree of oxidation which is
apparently of most importance. Like alcohol in small
doses, though in a far greater degree, it stimulates
muscular contraction and nervous activity in general.
The effect of alcohol depends on quantity in a much
higher degree than is the case with strychnine. One
can scarcely believe that the latter robs the blood of
an appreciable portion of its oxygen. It appears,
indeed, to strike a certain note, a note of diminished ma
oxidation, and to cause the molecules of the nerve
centres to vibrate to this tune. The more stable it is
—and strychnine is supposed to be relatively a very
stable compound—the longer will it make its presence
felt dynamically. All the most powerful drugs may
be supposed to act dynamically rather than by virtue
of the quantitative chemical changes they produce.

* See p. 25.

+ Letourneau, ‘Biology,’ p. 114. They (proteic substances)
also furnish—but by incomplete oxidation, by degradation—
asparagin, of which we have spoken, and, without doubt, the

vegetal alkaloids (quinine, morphine, strychnine, etc.), quater-
nary, but not proteic, substances.

Physio-
logical an-
tagonism.

Action
and re-
action.

28 THE ACTIVE FORCES OF LIVING ORGANISMS

It is not easy to understand how a drop or two of such
@ poison as prussic acid (HCN) can kill as it does,
unless it be that the absence of any oxygen, and the
presence in it of hydrogen, carbon and nitrogen, cause
a note of arrested oxidation to be struck even more
pronounced than is the case with strychnine. The
fact that prussic acid, when produced in the course
of nature, is found hidden away in the kernel of
a hard peach-stone certainly suggests a state of
diminished or arrested oxidation.

Drugs are sometimes said to be physiologically
antagonistic which are not really so in their mode of
action, or are so only in a limited and partial manner.
Thus strychnine (C,,H,.N.O,) is spoken of as the
physiological antagonist of physostigmine (C,,;H,,N,0,),
and may be used as an antidote in poisoning by that
drug. Yet the action of the two is in some important
respects similar: both produce constricting effects,
and are used in constipation. If we look at the matter
from the dynamic point of view, and consider the
molecules of our nerve-cells as vibrating in a given
manner according to the dynamic influence of their
chemical surroundings or environment, we shall at
once understand that a slight change in the latter
might suffice to alter the mode of vibration, or, in
other words, produce a different and apparently
antagonistic physiological effect.

In estimating the physiological effect of any drug,
both its action and reaction must naturally be taken
into account, and since all drugs act by influencing

THE ACTIVE FORCES OF LIVING ORGANISMS 29

the rate and degree of oxidation, it is very evident
that the amount of oxygen contained in them in
proportion to the other elements, and perhaps espe-
cially to nitrogen, is of considerable importance.
Indeed, the degree of oxidation of all vegetal products
is probably one of the chief factors, though, of course,
not the only one, in the determination of their
chemical characteristics and physiological effects.
Bitters and alkaloids in general may be said to
produce in the first instance an astringent or con-
stricting effect on the tissues with which they come
in contact. Whether or not this result leads to a
diminution, or to an increase, of oxidation depends
on the condition of the tissues previously in respect
to contraction or relaxation, and this naturally applies
in the case of strychnine; but it is certainly true that
the more any tissue is contracted, the less easily does
oxidation in it take place. The action, however, of
drugs which produce constriction of the tissues, and
so diminish oxidation, is probably always followed
by a reaction in the opposite direction, which varies
very considerably in different cases, depending partly
on the chemical composition of the alkaloid or bitter
employed, and partly on the physiological condition
of the person taking it. There are, indeed, certain
general truths connected with the action of all drugs
which one may express as follows :

All drugs influence the rate and intensity of the
oxidation of the tissues both by their action and by
their reaction.

The
apparent
oHeet of
drugs on
the gray
matter.

30 THE ACTIVE FORCES OF LIVING ORGANISMS

Every increase in the amount of oxygen in a tissue
leads to, or is accompanied by, expansion, whilst
every decrease in the amount of oxygen in a tissue
leads to contraction. The presence of carbonic acid
in the tissues is also probably a stimulus to con-
traction.

The mode of vibration of the molecules of nerve-
cells depends on the manner, degree, and frequency
with which the variations in the state of oxidation of
the tissues are produced. Excessive oxidation causes
relaxation.

The period and degree of action and reaction of all
drugs varies, firstly, according to their composition, and,
secondly, according to the habitual mode of vibration
of the molecules in the nerve-cells of the individual.

If you scrape some of the gray matter from the
brain of an animal which has been recently killed,
and tease one portion of it on a glass slab or small
dish with water, another with a weak solution of
acetic acid, and a third with a fairly strong solution
of strychnine, you will notice that the first of these
is more milky in appearance than the other two;
and whilst the cells in the watery specimen show a
tendency to dissolve and become fused, those in the
strychnine and acetic acid are inclined, if anything,
to contract and appear curdy or caked. Under the
microscope the three specimens give corresponding
results, a strychnine preparation being especially re-
markable for the sharpness of the outlines of the
nerve-cells and of their granular contents. If, again,

THE ACTIVE FORCES OF LIVING ORGANISMS 31

you leave a brain for some weeks in strong alcohol, it
becomes, as is very well known, hard and compact.
The meaning of this is doubtless that a general con-
traction of the molecules, of which its substance is
composed, has taken place; they have, that is to
say, grouped themselves in closer order. The results
thus obtained indicate to some extent the physiological
action of the various substances mentioned on the
nerve-cells in a living animal. If we adopt the
modern view that ether permeates all matter, it is
evident that the molecules of nerve-cells must be sur-
rounded by it. When, therefore, they vibrate, as in
nervous action they probably do, there is, as it were,
a link between them and the molecules of any foreign
substance—such, for instance, as strychnine in the
blood—and the movements of the nervous molecules
would, under these circumstances, naturally tend to
become influenced and modified by their surround-
ings; and this, it may be supposed, would occur
whether or not the strychnine molecules were taking
part in the chemical action going on in the blood or
lymph around the nerve-cells.
If we suppose that the molecules of nerve - cells The

: . 2 s a nature of
vibrate in agreement with the degree of oxidation physio-

and the degree of contraction of the tissues to which oe
they correspond, it is evident that any change in the
latter must be followed, or accompanied by, a modifi-
cation of the vibrations of the former; therefore,
when the system is stimulated to increased oxidation

these vibrations must be affected thereby. But as the

32 THE ACTIVE FORCES OF LIVING ORGANISMS

effect of the stimulus decreases, the molecules of the
nerve-cells conforming to the change in the conditions
of their environment take upon themselves an altered
form of vibration—one, that is to say, which corre-
sponds to a state of diminishing oxidation. If the
stimulus to oxidation were abnormal or excessive,
the amount of carbonic acid produced would naturally
be so also, and the presence of a larger quantity of
this gas in the blood than usual—larger, perhaps,
than the circulatory and respiratory systems could
readily cope with—would tend to modify the vibra-
tions of the molecules of the nerve-cells. An excess
of carbonic acid in the b ood, even when the supply
of oxygen is made ample by artificial means, produces,
it is said, a narcotic effect, acting not only on the
respiratory centre, but on the central nervous system
and brain.* Carbonic acid also stimulates the
respiratory muscles and causes deeper breathing, and
if it act in the same manner on the tissue of the
lungs and pulmonary vessels, either directly or indi-
rectly, it would also produce contraction, it would
seem, in these parts, and so diminish the aeration of
the blood. If we look upon all contraction as the
passage from a higher to a lower state of oxidation,
it is easy to see how carbonic acid, which represents
the latter, should cause increased muscular action so
long as the muscular tissue is fairly well supplied with
oxygen.

There are many drugs, including probably the

* Foster, loc. ctt., p. 601.

THE ACTIVE FORCES OF LIVING ORGANISMS 33

majority of bitters, alkaloids, and narcotics, the
primary effect of which is to diminish and not to
increase oxidation ; and it is clear that when under
their influence a variation in the vibrations of the
nerve-cells takes place the change or reaction would
not be in the direction of diminished oxidation and
greater contractility, but of increased oxidation and
greater expansion, going in some cases so far as ex-
treme laxness. It therefore becomes a question of
some moment whether the action and reaction of all
drugs should not be considered primarily from the
double point of view of their effect on the degree of
contraction and of oxidation of the tissues. In so
doing, however, it is essential to remember that the
reaction of a drug may be beneficial or the reverse,
but that in general it is more permanent and lasting
than the primary action. This is a fact which is the
more likely to be overlooked, since one is always
inclined to ascribe improvement after medicinal treat-
ment, especially in the case of many tonics, to the
action of the drug administered, whereas in reality it
is frequently due to the reaction of the system after
the drug has ceased to act. Nor is this, as at first
sight might appear, a matter of slight importance, for
it is evident that in the case of a patient, the vibra-
tions of whose nerve-cells tend habitually to the side
of excessive contraction and diminished oxidation, the
application of a tonic, which by reaction produces
these very effects, could only ultimately increase the
evil, whereas in cases of an opposite nature it might
3

34. THE ACTIVE FORCES OF LIVING ORGANISMS

lead to gratifying results. Diminished oxidation,
however, though frequently due to excessive con-
traction of the nerve-cells, may also be caused by the
opposite tendency, especially when this laxness is of
such a degree as to produce considerable decrease in
blood-pressure. There are cases in which the nerve-
cells vibrate sometimes in a too contracted state, and
sometimes in a condition of too great expansion.
When the hyper-contracted state is habitual, it will
by degrees lead to diminished oxidation to such an
extent as to interfere with the due nutrition of the
tissues and thus indirectly bring about dilatation of
the arteries by weakening the muscular coats. In all
this, the habitual mode of vibration of the molecules
of the nerve-cells is the factor, to obtain control of
which should be the aim of treatment. Apart, how-
ever, from the use of drugs, reaction must be regarded
as a normal and natural event, for well-nigh all parts
of the human organism are subject to variations of
oxidation and of contraction, which are the primary
factors in all physiological action.

oe om The tissues of every living organism may be said

aeNaDe to consist, finally, like other substances, of molecules
and atoms; whilst surrounding these, and permeating
the whole is, we have reason to suppose, the ether.
In the manifold processes of oxidation which occur
both during functional activity and in a state of
repose, the molecules break down and are built up,
and this fact implies the existence of certain forces
by which these events are caused and controlled.

THE ACTIVE FORCES OF LIVING ORGANISMS 35

The blood carries the same raw materials to every
region of the body. By what means is the selection
in the various tissues made? and what are the con-
ditions which determine the nature of the chemical
combinations whereby the renewal of them is assured ?
Complicated in the highest degree though the pro-
cesses of metabolism taken separately undoubtedly
are, the main factors in them are, on the contrary,
probably very limited. Amongst them it is necessary
to concentrate one’s attention in the first place on the
tissues, the nervous system, and the ether.

When new molecules are formed in any tissue ie eal
they resemble the old in their chemical composition. radepialle
Though the various substances which go to form the cea
tissues are of a complex nature, and are elaborated
or prepared in other regions than those for which
they are finally destined—though, indeed, in some
instances, as in that of lecithin, bodies are found in
many parts of the organism in that form which they
retain when built up into tissue—-yet, speaking gene-
rally, the ultimate absorption of nutritive matter is a
process, not merely of physical attraction, but essen-
tially of chemical action also. The tissues constitute
the workshop in which new tissue is manufactured,
and they must therefore be regarded in a great
measure as the moulding agency. But if the tissues
are to exercise an influence of this kind they must be
active—they must, that is to say, transmit force either
directly or through some medium to the materials in
the lymph which bathes them. Now, if we suppose

3—2

The degree
of oxida-
tion going
on chiefly
deter-
mines the
nature of
the com-
pounds.

36 THE ACTIVE FORCES OF LIVING ORGANISMS

the ether surrounding the molecules to constitute a
medium capable of transmitting minute vibrations
exactly corresponding to the chemical composition of
each class of molecules, we shall be able to under-
stand—in part at least—how it is that the loose
materials in the lymph always group themselves in
each region of the body in the same proportions, so
that the continuity of the tissues is insured. To put
the matter briefly, environment determines the nature
of the new product.

But amongst the individual factors in this environ-
ment there is one, namely oxygen, which plays the
foremost part. Oxidation is, as we well know, the
pivot on which all metabolism turns, and a given
degree of oxidation of the tissues is one of the
conditions essential to the formation of new tissue.
Chemical bodies containing a large proportion of
oxygen must naturally be formed under conditions of
relatively higher or intense oxidation. The intensity
of oxidation is probably dependent partly on vibratory
influences, and partly on the presence of a given
amount of oxygen.

If we regard the ether as a medium permeating
the whole body, and everywhere surrounding the
molecules of which it is composed, we may suppose
that any movement whatever would throw it to a
greater or less extent into a state of vibration, and
with it the molecules also, so that they would react
upon the ether, and through it, as we have said,
upon the materials about to be formed into new

THE ACTIVE FORCES OF LIVING ORGANISMS 37

tissue. It is evident, therefore, that all forms of
movement, but especially those which are continuous,
may, and probably do, play a very important part in
the processes of metabolism. The influence of the
respiratory movements is especially worthy of con-
sideration in this respect. These produce a series of
variations of blood-pressure which are probably felt
throughout the whole organism, and can scarcely fail
to influence the mode of oxidation of the tissues.
When the skull of a living animal is removed, the
brain may be seen to rise up during expiration and
to sink during inspiration.* Expiration is held to
hinder and inspiration to facilitate the return of blood
from the brain, and it is evident that this applies
not only to the blood returning from that organ, but
also to that coming from other parts of the body.
At the same time, whilst venous pressure is diminished
during inspiration to the point of becoming negative,
arterial pressure is, on the contrary, increased,
though not in a manner which is exactly synchronous
with the inspiratory movement.+ The former, in-
deed, follows close upon the latter, and attains its
maximum only at the beginning of the expiratory
movement. These variations of pressure in the
thorax and in the vascular system in general must
lead to corresponding variations in the degree of
oxidation in the tissues; for, as the arterial blood-
pressure rises, so must the pressure of the lymph
and of the oxygen it may for the moment contain be

* Foster, loc. cit., p. 613. t Ibid., p. 614.

38 THE ACTIVE FORCES OF LIVING ORGANISMS

increased. But this increase in oxygen pressure is
accompanied by a decrease in carbonic-acid pressure,
due to the negative pressure in the veins. Meta-
bolism must therefore possess a rhythmical character ;
moreover, it is not improbable that as the blood-
pressure rises and falls with the respiratory move-
ments, the tissues also expand and contract. Thus,
when arterial pressure has attained its maximum at
the beginning of expiration it seems likely that the
transfer of oxygen to the tissue, which may then be
supposed to take place, is accompanied by a certain
degree of expansion. Indeed, unless we imagine
some such movement to occur in the nerve-cells, it is
difficult to conceive how the molecular and chemical
action going on in them can govern the metabolic
processes taking place in the tissues. However this
may be, it will be seen that, so long as respiration
continues, molecular movements and ethereal vibra-
tion never cease in the nervous system and tissues
generally, so that even in the deepest sleep there are
forces at work which determine the mode in which the
building up of raw material into new molecules shall
take place. But though the respiratory movements
and the influence of nervous vibration upon the
tissues may be regarded as contributory causes in the
formation of new molecules, yet the facts that meta-
bolism will go on in the stomach after most of the
nerves to that organ have been cut, and that growth
in the case of the hair and nails will continue after
death show that chemical action, the ether and

THE ACTIVE FORCES OF LIVING ORGANISMS 39

molecular environment of a given kind are alone
essential. These are also the chief factors in vegetal
growth in which ethereal motion in the form of light
plays so important a part.

Of all elements oxygen is admittedly the most The ee
negative, or, in other words, the most attractive; and ee
although these terms are usually applied to it in an
electrical sense, yet all that we know of its behaviour
chemically justifies to a great extent an extension of
their meaning so as to cover this second form of
action. Electrical and chemical phenomena, espe-
cially in living matter, are so intimately connected
that it would probably be impossible to draw a clear
dividing line between them. When oxygen passes
from the capillary into the lymph surrounding the
tissues, it tends, we may suppose, by reason of its
attractive power, to group the other elements round
it so as to form new molecules, which, if the vibratory
conditions be favourable—that is to say, not excessive,
and yet sufficient—will then take place. In a similar
way, when the vibratory conditions become either too
weak or excessive, the oxygen breaks away from its
surroundings, forming new compounds. If the state
of oxidation of muscular tissue be variable, as we
have reason to suppose it is, this extreme negativity
of oxygen may be a factor of primary importance in
contraction; for when the diffusive or attractive influ-
ence of oxygen is diminished, it would seem likely that
the elements in those bodies which remain should
possess a greater power of attraction for one another.

Muscular
contrac-
tion isa
rocess of
eoxida-
tion.

40 THE ACTIVE FORCES OF LIVING ORGANISMS

When a muscle contracts in rigor mortis it will give
off a considerable amount of carbonic acid. It will
do this even if placed in a vacuum, after it has been
shown by means of a mercurial air-pump to contain
no free oxygen.* It is clear, therefore, that the
oxygen of the carbonic acid was held in the muscular
tissue either in that form or in some more complex
body. Since, however, carbonic acid is one of the
chief products of muscular contraction, not only in
rigor mortis but in the normal state also, there seems
to be some ground for supposing the muscular con-
traction to be essentially a process depending on a
diminution of the supply of oxygen in the tissue.
The more perfect the state of oxidation before the
contraction takes place, the greater the diminution
would naturally be under the influence of a sufficient
stimulus. Thus, though perfect oxidation is essential
to muscular action, the actual cause of the contraction
lies probably, as remarked, in a diminution of the
state of oxidation of the tissue taken as a whole.
There appear, however, to be reasons for believing
muscular tissue to be of a complex nature, and it is
likely that one or two only of the various bodies which
compose it break up in the contraction, whilst the mole-
cules of the other bodies coming under the influence,
so to speak, of a wave of diminished oxidation, group
themselves in the peculiar manner which constitutes
muscular contraction. The production of heat during
the contraction can only be attributed in a general

* Foster, loc. cit., p. 100.

THE ACTIVE FORCES OF LIVING ORGANISMS 41

way to this movement of deoxidation, since it is not
known whether the carbonic acid is produced at the
moment, or, having been previously formed, is merely
liberated. It is when we look at muscular contraction
from the point of view of the tissue which remains
after the oxygen has been expelled in the form of
carbonic acid or otherwise that it will appear to
us to be essentially a process of diminishing oxida-
tion.

Although functional exercise is rightly regarded as pond 4
one of the conditions most essential to growth and favour-
development, there is probably no reason for sup- Saaetieihy
posing that both katabolism and anabolism take place
to'an equal extent either during action or during
repose. The recuperative influence of sleep and the
lassitude and weakness which is caused by a lack of
it seem to point to the conclusion that the anabolic
factors predominate in this state. As to the general
character of sleep there can be very little doubt.

The decrease in the amount of carbonic acid produced
shows that it is essentially a period of diminished
oxidation, and this condition is, it would seem, the
most favourable for the building up, if not of all the
tissues in the body, yet at any rate of some of the
most essential, and especially, one may suppose, of
nervous matter, which in its chemical composition
contains relatively so small an amount of oxygen.
Absolute rest of body and mind has been recognised
to be one of the most efficient methods of restoring
nervous power. Amongst farmers it has long been

The con-
tractility
of nerve-
cells.

42 THE ACTIVE FORCES OF LIVING ORGANISMS

a practice to keep cattle which they wish to fatten
in dark stalls, and whatever drawbacks it may have
from a sanitary point of view, there is little doubt
that by diminishing the supply of light, and thereby
limiting the degree of oxidation, a more rapid gain in
weight may be obtained. Although the rapidity of
growth in children and young animals is doubtless
due to several factors, one of the most important is
undoubtedly the amount of sleep which they get. In
the first few weeks of its life an infant will often sleep
eighteen or twenty hours out of the twenty-four, and
the longer it sleeps the better it will thrive. It is
said that during sleep the brain is anemic, and the
constriction of the pupil of the eye suggests contrac-
tion of the cerebral bloodvessels. However this may
be, the diminution of respiratory movements, the
slowing of the pulse, the lessened production of urea,
and the lowered temperature, all indicate decreased
metabolism; and yet such metabolism as still takes
place is, we may suppose, anabolic in its character
rather than katabolic.

During expiration, as already remarked, the brain
as a whole rises and the blood-pressure sinks; whilst
during inspiration the reverse happens, the brain
sinking and the arterial blood-pressure rising. These
variations, it was said, cannot but exercise a certain
influence on the nerve-cells, and we may expect them
to be accompanied by appreciable changes in the state
of oxidation and of contraction. The question of the
contractility of the nerve-cell is, however, one of such

THE ACTIVE FORCES OF LIVING ORGANISMS 43

general interest that it may be worth while to con-
sider certain other aspects of it. The power of
attracting and repelling is, as everyone is aware, one
of the primordial properties of matter, and is fre-
quently brought into play by the variations of chemical
environment which in any given case may happen to
obtain. Since in animal tissues oxidation and de-
oxidation are the common basis of all movement, the
vibrations of nerve-cells may without doubt be attri-
buted to the same general cause, and if this be so,
then variations in the mode of vibration must evidently
depend on the degree of oxidation. But it is cer-
tainly very difficult to imagine any variations of
movement and of position amongst the molecules of
nerve-cells which would better correspond to changes
in the degree of oxidation than would variations of con-
traction and expansion. If the nerve-cell itself were
contracted, or if within it the molecules were grouped
more closely together—it may be in tiny collections
such as would give it the granular appearance we
know it to possess—the molecules would, one might
suppose, react on one another with greater rapidity,
and if the grouping were not too close, with greater
intensity. Such a grouping would correspond to a
state of diminished oxidation, for many of those drugs
which produce a diminution of oxidation cause con-
striction or drawing together of the tissues with which
they come in contact, and within certain limits an
increase in the intensity of nervous vibration. The
nature of glandular secretion during very violent

44 THE ACTIVE FORCES OF LIVING ORGANISMS

attacks of asthma, when the supply of oxygen is to
a great extent cut off, is of such a kind as to suggest
very rapid production and incomplete oxidation.
Whether this result is a direct or an indirect one
really matters little, for it is evident that both in the
gland and in the nerve-cell a diminution of oxidation
causes excessive activity or movement. Contractility,
moreover, is a property of protoplasm in general, and
there is the less reason to make an exception of
nervous matter since the axis cylinder of a nerve-
fibre resembles chemically in its general features
muscular tissue. Experiment also confirms the
view that the nerve-cell, if it behave as ordinary
protoplasm, contracts and expands in accordance
with the changes in its chemical environment, and
in this respect the following passage is of great
interest :

‘Referring again to Ehrlich’s observation, we can
see that if anesthetics and hypnotics cause contrac-
tion of the protoplasm in the cells of nervous centres,
they will thus lessen oxidation and tend to diminish
functional activity. Such a contraction might be
caused not only by alkaloids like morphine, but by a
mere change in the reaction of the cell or of the fluid
surrounding it. When free cells, such as amcebe or
infusoria, are treated with very weak acid they con-
tract, and with weak alkali they swell up. It there-
fore seems probable that mere diminution of alkalinity
by the products of tissue-waste may tend to lessen
oxidation in the brain-cells by contracting the proto-

DIAGRAM TO ILLUSTRATE THE PART WHICH THE
ETHER PLAYS IN NERVOUS ACTION.

a, b, Marconi’s wireless telegraph poles ; c, the ether in a state of
tension ; d, a nerve-cell permeated by the ether, which undergoes
variations of tension as the molecules of the cell move hither and
thither as a result of oxidation in part of the cell ; ¢, a nerve fibre ;
> ><><, a stratum of ether, variations in the tension of which,
caused by molecular movements in the fibre, give rise to the
current of action ; 7, a muscle also permeated by the ether, varia-
tions in the tension of which help to convey the nerve impulse to
the molecules of the tissue.

To face p. 45,

THE ACTIVE FORCES OF LIVING ORGANISMS 45

plasm at the same time that the changed reaction
lessens their affinity for oxygen.’ *
Since every increase of blood-pressure must per- Variations

in the
force mean an increase of oxygen pressure round the epee of
: : : e ether
nerve-cell, we may suppose that with every inspira- as the
E a -, cause of
tion fresh molecules of oxygen are squeezed into its the

substance, and passing amongst the granules of which eer niny i. a
it is composed, oxidize, or become allied with some fibre
of the elements present. Whilst at each increase in
the supply of oxygen to the nerve-cell some of the
molecules of the latter break up and are got rid of,
the remaining ones may be supposed to come under
the influence of a vibratory wave, the character of
which is determined by the degree of oxidation. This
wave is transmitted from the cell to the periphery in
the case of an efferent nerve, probably by molecular
movement in the nerve-fibre. But at the same time
that this molecular transmission takes place a second
event occurs: the molecules of the nerve-cell are
everywhere surrounded by ether, and along the
nerve-fibre to the periphery there is also a stratum
of ether. The movement of the molecules is there-
fore communicated to this other medium in which
certain variations of tension make themselves felt.
These variations are what is termed ‘the current of
action’ or ‘negative variation.’

In addition to variations of blood-pressure, the The infiu-

ence of

degree of oxidation is influenced by other factors, as, functional
activity on
* Sir T. Lauder Brunton, Introduction to ‘Modern Thera- eee

peutics,’ pp. 112, 113.

46 THE ACTIVE FORCES OF LIVING ORGANISMS

for instance, by the amount of oxygen in the blood,
by the presence or absence of chemical substances
conducive or otherwise to oxidation, and by the
degree of vibratory activity in the nerve-cell. Both
the degree of oxidation and of movement in the
protoplasm of the nerve-cell are naturally greater
during functional activity than in a state of repose,
and less during sleep; and if in the first of these
conditions a note of increased or diminished oxida-
tion is repeatedly struck which considerably exceeds
the normal limit, the molecular movements of the
cell will, little by little, become exaggerated, not only
when the cell is active, but also, though to a slighter
extent, when it is, relatively speaking, at rest, and
thereby the nature of the metabolism may be altered.
These If, as there appears to be reason to believe, contrac-
contrac. tion and expansion constitute a most essential part of
Sia nervous action, the nervous system may be likened to
aaa a pendulum, swinging now to the side of increased
oxidation, and now to that of decreased oxidation.
Yet in order that the simile may fully represent not
only normal action, but pathological action also, it is
necessary to suppose that the point of attachment or
pivot on which the pendulum swings may be shifted
to a greater or less extent towards increased oxida-
tion and greater expansion, both of which then
predominate, or towards decreased oxidation and
greater contraction, which in like manner become
excessive. The rhythmic movements continue as

before, in accordance with the variations of blood-

THE ACTIVE FORCES OF LIVING ORGANISMS 47

pressure; but as the conditions under which they
have been going on are such as lead chiefly to con-
traction, or chiefly to expansion, so does their general
character incline more in this or that direction. What
those conditions are has already been described in
dealing with physiological reaction. Irrespective of
the influence of respiratory movements on blood-
pressure, vaso-motor changes, when excessive and
frequent, are probably one of the chief causes of
an ill-balanced state of metabolism, although the
anatomical relations of the vaso-motor centre to the
rest of the nervous system, and especially to the
brain, are but little known.

What is the nature of the force transmitted by a ahs tains
nerve-fibre? Is it molecular? is it chemical or atomic? nervous
is it electrical? There are many who deny that the aes
nerve impulse is of an electrical order; but the state-
ments on this point are not absolutely conclusive,
although in some measure doubtless true. The facts
on which they rest are briefly as follows: The
velocity of an electrical current in a nerve-trunk is
far greater than that of a nerve impulse passing
along the same fibres. A nervous impulse is not
transmissible by an electric conductor—as, for instance,
by a copper wire. If you ligature a nerve, it will no
longer transmit nervous impulses, but will still act as
a conducting medium to an electrical current. A
crushed motor fibre which has lost its functional
power will generate electricity for a time.

With respect to the arrest of a nerve impulse by a

48 THE ACTIVE FORCES OF LIVING ORGANISMS

ligature, it may be argued that the difference in
electrical potential between one part of the body and
another being always very slight—much less indeed
than that which exists between the two plates of a
battery—the interruption of the nerve current might
be more easily effected than that of the electrical
current. The former is also very much the weaker of
the two, and the rate at which it travels suggests
either that it has to overcome a certain degree of
resistance, due possibly to the slight difference of
electrical potential already mentioned, or that it is
generated anew all along the fibre. When a nerve
impulse takes place, it is accompanied by an electrical
change passing along the nerve-fibre. This change,
the negative variation or current of action, as it is
called, is evidently bound up with certain changes in
the nerve-cell, the nerve-fibre, and its peripheral
ending. Yet no development of heat nor signs of
chemical action have hitherto been detected in a
nerve-fibre after action, so that either they are so
minute as to escape detection, or the only change is a
molecular one, accompanied by an electrical move-
ment or variation. What, then, is the nature of
the nervous impulse ?

Electrical To meet all the necessities of the case, it seems as

vibration , f A
isalways though we must look on it as a compound in which
connected a %
with the elements are chemical, molecular, and electrical.
hemical ‘ Bice
crwith Really, if we reflect, we shall probably find it im-

moc possible to exclude any one of the three. From the

electrical variation, or current of action, of which

THE ACTIVE FORCES OF LIVING ORGANISMS 49

we have conclusive evidence, we may certainly infer
either chemical or molecular action. Has, indeed, we
may ask, an electrical current ever been known to
exist which has not originated in, been accompanied
by, or given rise to, chemical—that is to say, atomic—
action or to molecular vibration ? When the lightning
flashes from the clouds on a midsummer’s day, are
not the molecules of water and air vibrating intensely,
owing to the heat and friction to which they are sub-
jected? When a very powerful current of electricity
is made to pass along a thin copper wire, will it not
cause the molecules to vibrate until they glow with
red-hot intensity? May we not believe, therefore, ead
that the presence of electrical action in a nerve fibre
indicates that molecular vibration is taking place ?
The molecular element seems the more essential,
since without it it would be very difficult to explain
all the varieties of sensation, especially those forms
of it in which no end organ participates and, as far
as the periphery is concerned, little or no chemical
action is observable. In this category must be
classed many effects due to the tactile sense and
others belonging to the muscular sense. Some effects,
again, such as the lighter ones of the tactile kind, as,
for instance, tickling with a hair, seem so insignifi-
cant as almost to suggest an electrical origin, or, at
least, that electrical variation plays an important
part in them. In all such cases, if we exclude the
latter, molecular transmission is the only explanation
on which we can fall back; and it seems justifiable,
4

t0 THE ACTIVE FORCES OF LIVING ORGANISMS

therefore, to regard it as an essential factor in nervous
action.

The chemical element is also essential. Firstly,
because sensation is impossible without oxidation in
the nerve centres ; and, secondly, because certain forms
of sensation are directly due to chemical action at the
periphery. Lastly, the electrical element, accom-
panying as it does the impulse step by step, must,
one would think, for other reasons than that already
given, play some part in its transmission. It seems
contrary to all reason to suppose that an active force,
such as electricity, can be merely passive and exert
no influence on such loose and mutuable compounds
as those of living tissue. We know that when
passed through the tissues from a battery it induces
metabolism, and we may therefore infer that when
generated in the body it contributes to bring about
chemical action, if not in the nerve fibre, at least
in the nerve-cell. Indeed, if we adopt the modern
view of physicists, that the ether permeates all matter,
if we look upon it as being in a state of tension, and
if we consider electricity to be a movement in it due
to variations in that state, then it will seem impossible
that electrical action should take place without
reacting on the molecules of the region in which
it occurs. We may, indeed, with this torch in our
hands, penetrate into the very arcana of nervous
action; for if we suppose a certain number of the
molecules of a nerve-cell to be in the act of oxidizing,
and to produce thereby variations in the tension of

THE ACTIVE FORCES OF LIVING ORGANISMS 51

the ether permeating the cell, we can understand
how it happens that the other molecules, for the
oxidation of which the supply of oxygen is insufficient,
nevertheless become in a certain measure active, and
vibrate. Further, if again we suppose that light
consists of waves of force transmitted through the
ether, we shall see that the very origin of what
one may term our chief sense, if not electrical, is very
closely allied to electricity. We cannot shut our eyes Electrical
to the accumulating evidence of the electrical nature a,
of living tissue. Cutaneous, glandular, muscular,
and nerve currents are known to exist, and are, indeed,
a constant phenomenon in the functional activity of
the corresponding parts. The heart has two electrical
areas: there are retinal currents; there are currents
of injury. To produce a current it is sufficient, as
Galvani has shown, to make a muscle preparation
with a portion of the nerve attached, to raise the
latter, and allow it to fall suddenly on another
muscle preparation, or even on the same muscle,
so that it may unite as far as possible injured and
uninjured parts. In this case the current is gene-
rated and transmitted through muscle and nerve
alone without the aid of electrodes or wire. Thus,
it will be seen that variation of potential, or, as
one might call it, of ethereal tension coupled with
molecular agitation, will, under certain conditions,
produce muscular contraction. These facts, to which
others might be added, seem to support the view that
electricity in living tissue is by no means an inert
4—2

52 THE ACTIVE FORCES OF LIVING ORGANISMS

force, but one which contributes in a very real and
essential manner to the development of every kind of
physiological action. The passage of an electrical
current along a nerve fibre usually produces, it is
true, no specific form of sensation, whilst even the
electrification of parts of the cerebral cortex frequently
fails to yield any result of a functional order. If,
therefore, electricity, as it seems probable, does
play an essential part in nervous action, it can only
be, one would think, because the ether (regarding
electricity as ether in motion) takes upon itself, for
a certain distance, at any rate, the character of the
molecular or chemical action, which is the primary
origin of the nervous impulse, subsequent modifica-
tions always bearing a certain relation to it.

Many other curious phenomena of an electrical
order pass daily before our eyes. Women’s hair,
when combed, will often stand off from the head,
as though momentarily stiffened, and will crackle
when the comb passes through it. The cat which
rubs itself caressingly against your leg probably finds
its enjoyment in a flow of electricity, by which the
tension of the spinal centres is relieved and metabolism
stimulated. Some authors, it is said, cannot work
successfully unless they have a cat about them, which
from time to time they stroke. That part of massage
which is termed effleurage—that is to say, the light
rubbing of the skin—gives rise, especially when applied
to the back and spinal column, to a drowsy relaxation
precisely similar to that usually produced by electrical

THE ACTIVE FORCES OF LIVING ORGANISMS 53

treatment ina bath. Even the passing of the hand
over the tired brow or through the hair causes relief,
and the person operating will sometimes, if of a sensi-
tive nature, feel a tingling in his or her finger-tips.
Some persons are sent to sleep by these and similar
methods.

It is a fact, not without interest in its bearing on Electricity
the part played by electricity in the animal economy, the effect.
that the more a person is electrified, the more disposed cea atone
does his or her nervous system become to take upon wick it is
itself the character of the conditions under which it is *¢2@y""*
functioning. Thus, electrification of the body under
relaxing conditions will intensify their effect, whilst
electrification under the influence of a drug will very
greatly intensify both its action and reaction. The
nature of the result depends on other factors also
—on the kind of current, on its strength, and on
the parts to which it is applied. When the spinal
cord and cerebellum are electrified, the effect is more
pronounced than if the electrification be restricted to
the limbs and periphery in general. That electricity
should intensify any influence to which the body is
subjected is but natural, for its action is undoubtedly
to throw the molecules and atoms of the tissues into a
state of intense vibration, and matter in motion is
always more easily affected than when quiescent.

Take, for instance, the piece of iron which the
blacksmith fashions for a horseshoe, and which he
can mould to his fancy when the fire has made its

molecules vibrate.

Electricity
as an

almost
neutral
agency.

The effects
of high
altitudes.

$4 THE ACTIVE FORCES OF LIVING ORGANISMS

In the physiological effects to which we have
alluded electricity plays a, comparatively speaking,
neutral part, that chiefly of an intermediary. This,
moreover, is entirely in accordance with the theory
already advanced, that electricity is a mode of motion
of the ether; that the latter acts as a go-between
transmitting force, the kind of which depends on the
nature of the various forms of matter from which
it proceeds; and, lastly, that electrical potential is
due partly to the tension natural to the ether, and
partly to the action of excited groups of molecules
and atoms upon the ether, which, becoming imbued
with their special vibratory character, convey it to
other atoms and molecules, the attractive and repul-
sive power of one electrified substance for another
being thus evolved.

The nature of the air we breathe is universally
recognised as exercising a most marked influence
on the nutrition of the body, and from time to time
during the past century the subject has been
approached from the point of view of the effect
produced by residence at various altitudes. After
De Saussure, it was handled with great ability by
that much-abused French physiologist, Paul Bert ;
and quite recently an important work* by Mosso has
appeared, whose opinions in regard to some essential
points are at variance with those of the latter.

According to Flammarion, the pressure of the atmo-
sphere at 2,600 metres above sea-level is diminished

* ‘Der Mensch auf den Hochalpen.’

THE ACTIVE FORCES OF LIVING ORGANISMS 55

by one-quarter, at 5,500 metres by one-half, and at
9,500 metres by three-quarters.* For every 1,000
feet of ascent the barometric pressure falls, roughly
speaking, 1 inch, although in reality the fall is
slightly greater at low levels than at high ones.

The general effects of ascending suddenly to a Mountain
height at which mountain sickness supervenes in its beau
acute form are loss of bodily strength, helplessness,
a feeling of sickness, vomiting, a bluish coloration
of the skin, tingling of the ears, disturbed vision,
breathlessness, palpitation, and fainting.t It is
related that when cats are taken up into the moun-
tains above a certain height they succumb after
violent epileptic attacks. On human beings, how-
ever, the effects of high altitudes are very variable.
The monks living at the monastery on Mount
St. Bernard, which is 8,117 feet above the sea,
become asthmatic ; on the other hand, Potosi,{ in
America, is 8,960 metres above sea-level, and at one
time had a population of 160,000; whilst Quito,
Bogota, and Micuipampa are all above a height of
8,500 feet. On the Ibi Gamin, in Thibet, the brothers
Schlaginweit attained a height of 22,230 feet without
any other ill-effect than great fatigue.§

There are few problems even in physiology which
present greater difficulties than that of the effects of a
rise in altitude, the discussion of which has yielded

* Flammarion, ‘ L’Atmosphére,’ p. 72.
+ Mosso, loc. ctt., p. 229.
{ Ibid., p. 189. § Ibid., p. 230.

The chief
points.

The im-
portance
of the
nervous
factor.

56 THE ACTIVE FORCES OF LIVING ORGANISMS

such meagre results; nor is it intended here to do
more than draw attention to some of its more salient
aspects. The degree of atmospheric pressure, the
amount of oxygen in the air and in the blood, the
proportion of carbonic acid in the blood, the effect of
electrical or ethereal conditions, and the mode of func-
tioning of the nervous centres in the race or in the
individual—these are points which appear to merit
consideration.

That animal life may exist in a state of normal
health and activity at very great heights is clearly
shown in the case of the condor, which, according to
Humboldt, flies as high as 21,834 feet; whilst eagles
and vultures have even been observed by the Schlagin-
weits at a height of 23,000 feet above the sea.* These
facts considered in conjunction with the inability of
cats to withstand a height of only about 18,000 feet
point to the conclusion that the essential factor is
neither absolute atmospheric pressure nor the absolute
amount of oxygen in the air, but the readiness of the
nerve centres governing metabolism to adapt them-
selves to conditions more or less removed from those
to which the race or the individual has been habitually
subjected. In other words, a cat’s blood exposed to
the air at a given level above the sea would probably
oxidize as fully and as rapidly as that of an eagle,
yet the transmission of oxygen from the blood to the
tissues and the formation of carbonic acid does not
take place in a regular manner in animals belonging

* Mosso, loc. cit., pp. 21, 22.

THE ACTIVE FORCES OF LIVING ORGANISMS 57

to lower levels when transported suddenly to heights
above 8,000 to 9,000 feet. Mosso mentions, on the
authority of Hiifner, that hemoglobin artificially
prepared would absorb a normal amount of oxygen
even on the top of the Himalayas.* Analyses of
dogs’ blood by Geppert and Fraenkel showed that
the amount of oxygen in it was not diminished until
the atmospheric pressure had fallen to 410 mm.,t
although mountain sickness is often observed in a
violent form at a pressure of 500 mm., the equivalent
of a height of 3,300 metres. Hiifner even goes so
far as to say that mountain sickness cannot be
attributed to a chemical or physical change in the
blood until you reach a height of 9,000 feet.

The analyses just referred to demonstrated another abe rela-
important fact, to which Paul Bert had also drawn diminution

* e of carbonic
attention, viz., that as the air becomes more and acid and

more rarefied, the carbonic acid in the blood ie
diminishes more rapidly than the oxygen, the pro- °°*
portion being 1°63 of the former to 1:0 of the latter.
Mosso, who has performed many experiments and
collected a good deal of evidence all tending to
support this statement, is inclined to regard the
diminution of carbonic acid in the blood as the main
or most direct cause of mountain sickness. Doubt-
less the amount of carbonic acid in the blood
exercises a considerable influence on the respira-
tory centre, and it may be on the nervous system

* Mosso, loc. cit., p. 400.
} Ibid., p. 401. t Ibid.

The effect
of varia-
tions in
the rela-
tive
accounts
of these
gases,

58 THE ACTIVE FORCES OF LIVING ORGANISMS

as a whole; indeed, it has been stated that it affects
other parts of the nervous system, and especially the
brain, more markedly than the respiratory centre.*
The bare fact that arterial blood contains twice as
much carbonic acid as oxygen is enough to convince
one that it is an important factor in metabolism; and
when one reflects that with every inspiration the
oxygen pressure around the nerve-cells is increased,
and that with every inspiration also the carbonic acid
pressure round the nerve-cells is diminished by the
sucking action of that movement on the great
veins, surely this conviction must be still further
strengthened.

All metabolism may be said to take place, as we
have seen in the case of muscular contraction, between
certain limits of oxidation and of deoxidation, or,
if the expression be permitted, carbonic acidification.
It is impossible, in view of the composition of arterial
blood, to regard carbonic acid merely as a waste
product without influence on the nervous system,
for the proper functioning of which, indeed, a certain
balance between the two gases is probably essential.
An abrupt but continued alteration in the proportions
in which they figure in the blood, if excessive, results
in a disorganization of the nervous system. The
effect of carbonic acid on the nervous system. is
naturally very variable, depending as it does not
only on the degree in which it is present, but on

* Foster, loc. cvt., p. 601.

THE ACTIVE FORCES OF LIVING ORGANISMS 59

the degree of oxidation of the tissues. A slight
increase of carbonic acid stimulates contraction
whenever the tissues are sufficiently oxidized; and
similarly a slight increase in the amount of oxygen
in the blood, if absorbed by the tissues, stimulates
contraction whenever they previously have been
insufficiently oxidized. A great proportional excess
of either gas in the blood tends, on the contrary,
to diminish metabolism, and in some cases brings
about spasmodic action of the nerve centres. The
increase in the amount of carbonic acid which takes
place during violent exercise makes its influence felt
by rendering muscular contraction after a while more
feeble. Here, however, we have to consider not so
much the temporary fluctuations as the long-continued
changes due to differences of altitude. There is
reason to suppose that, although the mode of func-
tioning of the nerve-cells is at once modified by such
changes, they still retain for some time something of
the influence of the preceding conditions to which
they were subjected. It is probably this compromise,
so to speak, between the new and the old which is in
a great measure the cause of improvement. This
double action, indeed, suggests an explanation, and
probably the only one, of the bracing effect of high
altitudes ; for when an individual goes from a low
place to a high one, not only does his nervous system
come under the influence of a relatively greater
amount of oxygen in the blood, but it still remains for
some time under the influence of the pre-existing

60 THE ACTIVE FORCES OF LIVING ORGANISMS

relatively ample, or it may have been excessive,
amount of carbonic acid. When, however, at a given
height the increase of oxygen in proportion to the
carbonic acid in the blood exceeds a certain degree,
this condition is by no means favourable to health in
any save a few exceptional animals. This certainly
seems to prove that the relative proportions of these
gases in the blood affect the nervous system in a very
fundamental manner.

eae es Although the inspiration of oxygen and the expira-

atmo- tion of carbonic acid have been said to be influenced

eaten by physiological factors, it seems probable that the
main, if not the most direct, cause of the relative
diminution of carbonic acid in the blood is to be found
in the decrease of atmospheric pressure. The general
diffusibility of gases and liquids is, we may suppose,
increased as you rise in altitude. Under these
circumstances both oxygen and carbonic acid would
find a more easy passage to and from the lungs, so
that if we consider the events from this point of view
there would be a gain in the amount of the former
and a loss in respect to the latter. This, indeed,
agrees with the results of analysis already mentioned.
The gain in oxygen is, however, only relative, for
the actual amount of that gas in the blood at a very
great height decreases. Nor is this compensated by
deeper breathing save in exceptional cases of ex-
haustion. The rule, indeed, seems to be rather that
as you rise in height the respiratory movements
become shallower, and this may be attributed both to

THE ACTIVE FORCES OF LIVING ORGANISMS 61

the greater ease with which the air enters the lungs,
necessitating less respiratory effort, and also to the
diminution in the amount of carbonic acid in the
blood, whereby the natural stimulus to the respiratory
centre is lessened. :

There is a certain amount of evidence which tends
to show that this intensity of chemical action is
diminished as the atmospheric pressure falls. Ac-
cording to Dr. Saussure fire does not burn well on
Mont Blanc,* and it is necessary to blow it continually
in order to prevent it from going out. Although
water boils at 84°03° it requires more time, and an
amount which takes half an hour before reaching the
boiling point upon the mountain would, with the
same apparatus and the same amount of alcohol,
attain that degree in twelve minutes at sea-level.t+
Tyndall found that stearin candles lasted longer on
Mont Blanc than in the valleys below, and attributed
this fact to the cold. But this conclusion was
disproved by Benedicenti, who raised the temperature
of the air surrounding the candles and oil-lamp which
he used, and still noticed a marked decrease in the
rate of consumption.t These examples tend to show
that as you rise in height oxidation becomes less
rapid. Curiously enough, however, an increase of
the pressure of oxygen when carried beyond certain
limits produces the same results. When the pressure
of oxygen is very high, even phosphorus will not

* Mosso, loc. ctt., p. 267.
t+ Ibid. { Ibid., p. 268.

Diminu-
tion of

chemical

intensity

in high
altitudes.

62 THE ACTIVE FORCES OF LIVING ORGANISMS

ignite,* so that one would be inclined to regard the
normal pressure at sea-level as the most favourable
for chemical action. Alcohol when taken at a great
height produces less effect than at sea-level, though
this may be attributed partly to its more rapid
elimination through the lungs and partly to other
causes. Speaking in general, therefore, diminution
of atmospheric pressure tends to restrict chemical
action. To what extent, however, this would hold
good in physiological processes it is probably im-
possible to say.

Observa- The view that oxidation is, in the absence of

radia hal counteracting influences, diminished as one ascends

a to very high altitudes receives confirmation from the
physiological results of many ascents and experiments.
When Tyndall, at the top of Mont Blanc, sank down
and fell asleep, Hirst woke him after a short while,
exclaiming: ‘ You have given me a fright. I did not
hear you breathe a single time, although I listened for
it for some minutes.’ Mosso, having taken respiratory
tracings of two soldiers at Turin, which is 276 metres
above sea-level, and at the Queen Margaret’s hut, at a
height of 4,560 metres, observed that although in one
case the respiratory frequency was increased, yet in
both the depth of respiratory movements was strikingly
diminished. Experiments on other persons yielded
like results, and were carried out so far as possible
under similar conditions at the high and at the low
level. One notable feature of breathing at great

* Foster, loc. cvt., p. 612.

THE ACTIVE FORCES OF LIVING ORGANISMS 63

heights is the oft-occurring and frequently regular
pause between the inspiration and expiration, as
though for a brief interval the need of fresh oxygen
were not felt by the organism, and life were, so to
speak, momentarily suspended. This is very clearly
shown in respiratory tracings taken from two soldiers,
Sarteur and Solferino. The case of Sarteur is of
peculiar interest, since his respiratory frequency fell
on one occasion to as low as eight per minute, although
he was one of the strongest men of the party, and on
being waked ate with appetite and felt well. These
tracings were taken at the Queen Margaret’s hut, and
very remarkable is the difference in respiratory
frequency, that of Sauteur being eleven and that of
Solferino twenty-one per minute, although they were
of the same age, almost the same size, had at the
time eaten the same kind of food, and had walked the
same distance. One sees from this example the
importance of the personal or nervous factor.
The respiratory frequency of a dog, subjected by Experi-

Mosso to the inhalation of air containing 16°7 per cna

. ‘ strate the
cent. of carbonic acid, rose from twelve per minute effect of

to as much as forty and forty-four.* Unfortunately, on

there is no evidence in this case of the depth of the leans
respiratory movements; but if carbonic acid be, as merits

is generally held to be the case, a stimulus to the
respiratory centre, the more rapid elimination of it

at high altitudes would naturally lead, as we have

said, to shallower breathing, and this in turn would

* Mosso, loc. ctt., p. 416.

64 THE ACTIVE FORCES OF LIVING ORGANISMS

to some extent tend to reduce metabolism. Experi-
ments in the pneumatic chamber show, as might be
expected, that the amount of carbonic acid expired in
the first half-hour is far greater than can be obtained
afterwards, even though the pressure be very greatly
diminished, so that the ultimate effect of greatly
decreased pressure, when prolonged, is to lessen not
only the actual amount of carbonic acid in the blood,
but also the production of it, or in other words to
retard metabolism.

The apn Many who have made a special study of the con-

fis blood dition of the blood in high altitudes concur in the

ables. opinion that it contains, as a rule, a greater propor-
tion of hemoglobin, whilst some aver that the red
corpuscles are also greatly increased in number.
Although Mosso does not share these views, and
expresses doubt, which is perhaps to a certain extent
justifiable, as to the reliability of the experiments
undertaken by the various observers, yet one can
scarcely refuse to recognise the general probability
of the facts asserted. If one be right in supposing
that chemical action is retarded and rendered less
intense as we rise in altitude above a certain height,
that in other words the life stream is rendered less
rapid, the sojourn in the system for a longer period
of iron and other chemical substances becomes not
only explicable but natural. Chlorophyll, one of the
chief sources of iron for grass-eating animals, is prob-
ably the same at all levels, but the rate of excretion
would depend on that of the vital processes in general.

THE ACTIVE FORCES OF LIVING ORGANISMS 65

If the intensity of these be diminished, a proportional
accumulation of chemical matter might doubtless be
looked for.

But if an increase of iron, of hemoglobin, or of the
red corpuscles be due, as seems likely, to diminished
intensity of metabolism, it would disappear as soon
as areturn to a higher degree of tissue change took
place; and it is generally recognised that the effects
of residence at high altitudes are somewhat evanescent,
more so in some cases, less in others, according to the
special conditions of life and the idiosyncrasies of
the individual. A relatively greater accumulation of
oxygen-carrying or oxidizable material in the blood
does not necessarily imply more rapid oxidation.
The tissues, not the blood, are the chief seat of oxida-
tion; and this is so partly because they are directly
connected by nerve fibres with the nervous system
which controls metabolism, and partly on account of
their chemical composition. The connection of the
blood with the nervous system is in this sense, so far
as we know, only an indirect one. Trade may be said
to be good when the demand is equal to the supply.
So also in the present case, though a plentiful amount
of oxygen in the blood may act as a slight stimulus to
metabolism, yet the latter depends equally on such
factors as exercise and the perfect functioning of the
nervous system. The amount of oxygen in the blood,
as also the amount of blood circulating in the nervous
system and the blood-pressure, and the amount of
carbonic acid in the blood, are all, however, important

5

The influ-
ence of a
pee may
e trans-
mitted
through
the ether.

66 THE ACTIVE FORCES OF LIVING ORGANISMS

factors in determining the nature and rate of meta-
bolism, for these constitute the environment of the
nerve-celland ina great measure influence the character
of its vibrations.

Although the beneficial effects of a slight rise in
altitude and the opposite effects of a great rise may
to a considerable extent be explained by referring
them to the variations in the relative amounts of
carbonic acid and oxygen in the blood, yet there are
cases in which the solution of the problem must be
sought in the influence of other factors. Residence
on the top of a hill at a comparatively low level is
frequently more bracing in its effects than a sojourn
of the same duration in a hill-encircled valley far
above it in height. Moreover, the beneficial influence
which a situation of the former kind exerts on many
constitutions is not of an evanescent character, and
is often connected with a rise above sea-level so slight
as to be quite inappreciable from the point of view
of diminished atmospheric pressure. It has been
suggested that such results are due to electrical
influences. The degree of negative attraction of the
earth varies, it is said, very considerably in different
situations. Those which are free, open, and elevated
as compared to the surrounding land are less negative
than those which are low-lying, damp, and encircled
by high hills. If we look upon electricity as being
a mode of motion of the ether, and the latter as a
great and universal medium whereby matter in one
form or amount influences matter in another form or

THE ACTIVE FORCES Of LIVING ORGANISMS 67

amount, we shall probably see these facts in a new
and clearer light. Obviously, the effect which the
earth would transmit to us through the ether, whether
considered chemically or physically, would be mainly
one of inaction. Many people are influenced by sitting
on the ground even on the hottest and driest days
in summer under conditions which certainly do not
suggest the transmission of cold. Surely in such
cases we can explain the effect produced by supposing
the active ether of our bodies, active because chemical
action is always going on in it, to come under the
sway or influence of the more quiescent ether which
permeates the soil. A house situated on the top of
a hill, especially if this latter be isolated, stands away
and aloof from the ether of the earth to a far greater
extent than one built in a valley or hollow.

Since there can be very little doubt that the varia-
tion in the relative amounts of oxygen and carbonic
acid which are present in the blood exercises a con-
siderable influence on the mode of functioning of the
nervous system, it may be of interest to consider the
results of massaging the body from this point of view.
When the tissues are pressed and kneaded it is evident
that a certain quantity of waste products must be
squeezed out from them into the blood. Of these the
most important, so far as the nervous system is con-
cerned, is probably carbonic acid. The effect which
this increase will produce will naturally depend to a
great extent on the rapidity of the circulation, for the
quicker this is the sooner will the carbonic acid be

5—2

Some
results of
massage.

68 THE ACTIVE FORCES OF LIVING ORGANISMS

eliminated. In old persons this is a matter of some
importance, since they remain under the influence of
this excess of carbonic acid for a longer time and to
a greater extent than is the case with younger people.
In many instances, and especially when there is a
tendency to excessive vaso-motor action, a general
contraction of the bloodvessels takes place, and is
accompanied by pallor of the face. For a space also,
owing to the effect of this excess of carbonic acid on
the nervous system, metabolism receives a check.
This, however, is more than compensated for ere long,
for as this effect passes off, the vibrations of the nerve-
cells, changing with the altered conditions, swing round,
so to speak, to the side of increased oxidation and
expansion. The degree of vaso-contraction and of
vaso-expansion which occurs in any given instance
will depend not only on the extent to which massage
may have been carried, but also on the peculiarities
of the individual with respect to vaso-motor action in
general, and in almost any case they are likely to be
somewhat excessive. It is natural—nay, one may say
it is inevitable—that the increase of carbonic acid in
the blood, due to the squeezing of the tissues, should
affect the vaso-motor centre, for the relations of the
vaso-motor nerves to the blood may be supposed to
be of a closer nature than those of the other nerves.
Massage differs essentially from ordinary exercise in
the fact that the carbonic acid is heaped up without
any corresponding effort being made to get rid of
it, as, for instance, by the increase in the heart’s

THE ACTIVE FORCES OF LIVING ORGANISMS 69

action and respiratory movements when one is walking
or running. These conditions in their bearing on
nervous action are, it is clear, somewhat abnormal,
and unless neutralized or counteracted may be pre-
judicial.

The degree of ability to contract in a normal and peak:
not excessive manner is, in a certain measure, a criterion
of the vitality of the tissues, and it is interesting to
inquire in what way, if at all, this power may be
developed. The problem is certainly a very difficult
one. We know in the first place that, in contracting,
any tissue must pass from a-state of higher to one of
lower oxidation. We also know that the degree of
oxidation in the tissues is dependent on the mode
of vibration of the nerve-cells, which control meta-
bolism in the parts they supply. This being so, if
the nerve-cells are by artificial means raised for a
time to a state of increased oxidation, and then
allowed, as the effect of the stimulus passes off, to
sink little by little to a slower state of oxidation, the
metabolism of the parts with which they are connected
will, in a healthy subject part passu, undergo similar
changes. The inevitable nature of this change in
nervous vibration was pointed out in dealing with
physiological reaction, and though slight increases
and decreases of oxidation and of contraction or
expansion of the tissues are normal events, it is very
essential to keep them within the fairly narrow limits
of a healthy state. When the system has gone beyond
these limits, recovery may to some extent be caused

70 THE ACTIVE FORCES OF LIVING ORGANISMS

by producing effects which on the whole are opposed
to the predominating condition, be that one of hyper-
contraction or of hyper-expansion and relaxation.
There are many ways of increasing oxidation in the
nerve-cells, and some of these may be supposed to
produce by reaction a constricting effect on the blood-
vessels. Meat in general, and especially raw meat
or a fresh extract of meat in which the action of the
hemoglobin has not been destroyed, stimulates oxida-
tion. Whether they do this by reason of the chemical
constituents with which they enrich the blood, or by
causing a reflex action through the nerves of the
stomach, is hard to say; but carnivorous animals
are undoubtedly those in which muscular contractility
is most developed, and which at the same time are
most inclined to give themselves up to long periods
of inaction. It is usually supposed that a cold bath
produces a bracing or constricting effect, and though
there is apparently no reason for doubting this, it is
by no means clear how this result is brought about.
The tissues in general, and especially certain parts,
such as the hands and feet, show a tendency to swell
with heat and to become constricted under the influence
of cold. Heat, moreover, is more conducive to chemical
action than cold. Is the effect of a cold bath, we may
therefore ask, mainly a direct one accompanied by
dynamic changes in the vibrations of the nerve-cells,
or is it an indirect one caused by vaso-motor action
at the periphery and in the nervous system? When
cold water is applied in sufficient quantity to the skin,

THE ACTIVE FORCES OF LIVING ORGANISMS 7i

a contraction of the subcutaneous bloodvessels may
be supposed to take place, with the result that the
internal blood-pressure and the supply to the internal
organs, and presumably to the central nervous system,
are increased. After a cold bath, however, every effort
is usually made to bring the blood back to the skin,
which, of course, implies a slight withdrawal of blood
from the nerve centres, so that the latter may be
supposed to pass from a higher to a lower state of
oxidation. If we exclude the vaso-motor factor in its
bearing on the central nervous system, it is rather
difficult to understand how a bracing effect can be
produced, seeing that the skin, owing to the friction
to which it is subjected, receives a more abundant
supply of blood after the bath than before. At the
same time, though this movement of reaction is one
of dilation, there is a general vaso-motor movement
on a large scale, and this may give rise to secondary
effects. On the other hand, the general effect of cold
must be very great, or it would not be possible to allay
fever by means of it, and in such cases the aim seems
to be to produce a direct effect, and not one depending
on reaction.

It seems highly probable that the contractility of
the. arteries is to a great extent dependent on the
relative proportions of the two gases—carbonic acid
and oxygen—which constitute, as it were, the limits in
the movement of contraction; that is to say, in the
movement from a higher to a lower state of oxidation.
Although the amount of the former can be increased

The influ-
ence of
pre-exist-
ing con-
ditions.

Applica-
tion of the
theory of
the

ethereal
nature of
electricity
to physio-
logy.

72 THE ACTIVE FORCES OF LIVING ORGANISMS

by massage for a short space of time, yet it is very
difficult to produce in this way the continuous yet
fairly regular variations which obtain under conditions
of health and rapid metabolism.

Nervous action, whatever may be its special features,
always consists of certain groupings of the excitable
molecules which constitute nervous matter. These
groupings may be normal or they may be abnormal
and pathological, and in both cases the degree of
permanence of the character they possess will depend
on the force and duration of the influences to which
they are subjected. As bearing on the phenomena of
metabolism, it may be said that absolute changes in
the mode of vibration of the nerve-cells are very rare,
especially in natures which are not hyper-sensitive or
excitable. In passing from one set of conditions to
another there is always something of the old influence
still acting and blending with the new. This is a point
which must be borne in mind in estimating the effect
of residence at any given altitude, and, above all, in
interpreting the results obtained from experiments in
the pneumatic chamber.

No truly systematic theory of the nature of physio-
logical processes can be evolved which is not based
to some extent on conceptions of the fundamental
relations of force and matter, or, to use the alternative
phrase, of matter in motion. In this respect it
therefore becomes necessary to refer briefly to certain
possible deductions from the general views already
expressed. We started, it will be remembered, by

THE ACTIVE FORCES OF LIVING ORGANISMS 73

supposing that the ether is matter in a state of infinite
division ; that matter itself as distinguished from free
ether consists finally of atoms, which are in reality
little whirling masses of ether, the specific motion of
which gives them rigidity and assures their separate
existence ; that this specific motion is probably tem-
porarily disturbed or in some way altered at moments
of chemical action; and, lastly, that the free ether
surrounds all molecules and atoms, thus permeating
to a greater or less extent all forms of matter, and
acting as a medium for the conduction of force
proceeding from one sort or collection of molecules
or atoms to another sort or collection. The force
transmitted we, suggested must be electricity. A
difference of potential we further supposed to depend
on the relative reactive power of any given class or
collection of atoms as compared with another class or
collection in respect to their properties of attraction
and repulsion, and also on a second and extremely
important factor, the state of tension of the ether.
According to these views, and, indeed, according to any
theory which admits the ubiquitous character of the
ether, whenever chemical action takes place a disturb-
ance of the ether must follow as a logical consequence.
Whether or not it will take the form of a regular
current depends, one would think, on the difference of
potential between the substance in which action is
first started and the surrounding substance, and on
the regularity of such action. But the conditions in
living organisms with respect to heat, movement, and

Views of
French
hysio-
ogists on
electro-
motory
action.

74 THE ACTIVE FORCES OF LIVING ORGANISMS

the loose character of the compounds comprising the
various kinds of tissue, are so entirely favourable to
chemical action that we may suppose the ether
permeating them to be continually in a state of
vibration. This we might infer from the existence of
glandular, cutaneous, retinal, and other currents with
which physiological research has made us familiar.
Knowing that these currents exist in the body, not as
solitary or haphazard events, but as regular concomi-
tants of functional action, there are grounds for
supposing, as we have already pointed out, that the
ether may at times play the part of a conducting
medium in many of those forms of chemical action in
which, as far as one is aware, no nervous cells or
filaments intervene in a direct manner. We are the
more justified in assuming this to be the case, since
the view that the passage of electrical currents,
especially the faradaic, through the tissues will cause
chemical action is fully admitted by specialists and
members of the medical profession in general. Some
noted French physiologists, as is shown by the pas-
sage quoted below,* have long been of opinion that

* Letourneau, ‘ Biology,’ p. 213: ‘To these conditions, already
so favourable to the osmotic exchanges, are added electro-motory
actions. This exceedingly interesting point of the physiology of
the capillaries has been elucidated by M. Becquerel’ (‘ Mémoires
et Comptes Rendus de Académie des Sciences,’ from 1867 to
1870) ‘in a series of important papers. If by means of a voltaic
pile we decompose water contained in a vessel divided into two
compartments by a membrane, we see the level rise in the
negative compartment. There is, therefore, material transport
from the positive pole to the negative pole. Something analogous

THE ACTIVE FORCES OF LIVING ORGANISMS 75

electricity plays an essential and regular part in the
complicated processes of metabolism.

As already mentioned, chemical action—that is to
say, the agitation of atoms—could not take place in the
tissues without affecting the ether surrounding them,
and the influence they thus exert, if their action be
regular, must of necessity be so also; so that we have
only to suppose electricity to be a mode of motion of
the ether, and to conceive a difference of electrical
potential as existing between the molecules on one
side of a capillary wall, or a membrane and those on
the other side, together with the usual conditions of
heat, motion, and ethereal tension, and variations in
the amount of oxygen, carbonic acid, and of the ee
constituents of other chemical bodies, in order to of atoms
explain the nature of the factors in metabolism. As clectaica)

regards the actual transport of atoms, this process is the body.
so strikingly analogous to that which is now generally

takes place in the capillaries. In consequence of the incessant
chemical mutations which are effected in the tissues and the
vessels, electrical currents are produced. The capillary is elec-
trized negatively on the exterior and positively in the interior of
its wall. The oxygen traverses the wall, and is deposited on the
external surface. As to the globules, they enter into contact with
the positive internal wall. The oxygen once filtrated into the
tissues oxidizes them, and gives rise to the production of carbonic
acid, which the electrical current tends to impel into the interior
of the capillary. In other terms, and leaving aside the old
notion of the two electric fluids, there is between the contents
of the capillary vessels and the histological elements of the
tissues a circular current—an electrical circuit—which carries
the oxygen to the outside of the vessels and brings back the
carbonic acid.’

Absorp-
tion in the
amosba.

76 THE ACTIVE FORCES OF LIVING ORGANISMS

regarded as the probable course of events in an
ordinary electrical cell that there should be the less
hesitation in accepting it as representing the truth, at
least in its main lines.

In order to study the processes of nutrition in their
simplest form it is necessary to begin by examining
them, so far as that is possible, in some unicellular
organism such as the ameba. We may imagine such
a one to have encountered some little edible particle,
and to be in the act of absorbing it. The granular
protoplasm of the amcba separates to allow it to
enter, pseudopodia are stretched out on either side ;
the body of the amceba then closes on the edible
particle, which is thus held within it until much of
the nutriment is withdrawn. By what forces is this
brought about? What prompts the ameba to seize
upon its food? Evidently there can be no question
of chance impact. The particle is not driven into the
amoeba by a stray current, for any force of this kind
would probably act on both alike. Moreover, if the
particle were not edible the amceba would not stretch
forth its pseudopodia, nor would its granular substance
divide so as to receive it. But in order that a
particle may be edible two things are necessary: it
must be soluble and must be capable of undergoing
oxidation ; a particle answering to these requirements
would show a marked tendency to enter into chemical
action, and as soon as it collided with the more highly
oxygenated substance of the amceba, a state of things
decidedly favourable to development in this direction

THE ACTIVE FORCES OF LIVING ORGANISMS 77

would exist. Chemical action once started would
cause, as is always the case, diffusion in the substance
rendered active, and the entrance of the particle in
the area adjacent to it would thus be provided for,
or at least facilitated. The chemical action would,
it may be supposed, cause some sort of vibration.
Whether this would be molecular or electrical we
cannot very well determine, though it seems natural
to suppose that as in the case of the nervous impulse
it would be of a compound nature. In any case, we
may speak of it in a general way as an oxidation
wave, and we may assume that it would cause in the
nucleus also a slight amount of oxidation. These
events constitute what one may term the chemico-
sensory factors in absorption. Though more com-
plicated they are of the same order in the higher
animals. Hydrification and oxidation in one form or
another are the chief processes. Chemical action,
chemico-sensory impulses accompanied by diffusion or
loosening of the surface in contact with the food—
these are the common factors in absorption in high
and low organisms, and to these must be added
another, viz., motion, which may be recognised by
the presence of muscular fibres in the mucous
membrane of the intestines as it may in the thrusting
out of the pseudopodia of the ameba. The exact
nature of the latter event is, however, wrapped in
considerable obscurity, although it seems to depend
on certain events taking place in the substance of the
amceba and in the nucleus.

The con-
catenation
of auto-
matic
actions
and reac-
tions in
digestion.

78 THE ACTIVE FORCES OF LIVING ORGANISMS

Secretion in the various portions of the digestive
system appears to be connected in a certain measure
with the chemical nature of the substances present in
it. Thus, when the food, rendered slightly alkaline
in the mouth by the saliva, descends to the stomach
it causes a flow of acid, and it is a well-known fact
that this effect can be increased by the use of weak
alkalies. The acid acting on the carbohydrates of
the food dextrinizes them, and dextrin has been called
a peptogen because it augments the secretion of pepsin,
an effect which, it is said, is still further increased
through the presence of meat. The acidified food in
turn, as it passes into the duodenum, acts as a natural
excitant to the flow of the alkaline bile, which, mixing
with the food, leads to further secretion in the glands
of the remainder of the intestinal canal. Throughout
the whole of the digestive tract there is, therefore, a
concatenation of action and reaction due to chemical
transformations in which differences of electrical,
potential, and variations of ethereal tension are pre-
sumably, as elsewhere, a not unimportant factor.
These facts lead to the conclusion that all the pro-
cesses of metabolism, including those of digestion, are
of an essentially electro-chemical nature.

The next step which it is necessary to take is to
consider the relations existing between metabolism
and the nervous system, and to discover, if possible,
to what extent the force generated in the electro-
chemical processes acts upon the nerve centres and
in what degree the latter react.

THE ACTIVE FORCES OF LIVING ORGANISMS 79

In nutrition, as we saw in dealing with the ameeba,
there are two factors—a chemico-sensory or electro-
- chemical factor and a motor, in higher organisms
a vaso-motor and intestino-motor factor. We know
that both the bloodvessels and intestines have their
respective motor centres in the medulla and spinal
cord, and the point—a very difficult one—requiring
consideration is whether nerve-cells are affected by
the force liberated in the chemical processes of meta-
bolism and to what extent. A question which presents
itself, therefore, at the very outset of this inquiry is,
Does chemical action give rise to nervous impulses?
To this an affirmative answer may be given. Not
only is it highly probable that our visual sensations
are due to chemical processes which are started in the
retina*—started in all probability by ethereal waves—
but it is almost certain that those of smell and taste
originate in a similar manner ; that is to say, through
chemical action. In the two latter cases a fluid is
secreted by the glands of the olfactory and buccal
mucous membranes, in which the particles to be
smelt or tasted are respectively dissolved. Chemical
force thus generated or liberated is at once transformed
into nervous impulses. With these facts before us it
seems natural to suppose that when chemical action
takes place in the stomach, intestines, and other parts,
as it does with greater rather than with less intensity,
nervous impulses would in like manner result. Indeed,

* Foster, loc. cit., pp. 1252, 1258.

Chemical
action as a
cause of
nervous
impulses.

80 THE ACTIVE FORCES OF LIVING ORGANISMS

it is difficult to understand how the nervous system
can react upon the digestive and other metabolic pro-
cesses unless it be affected by them. We may, it is
true, conceive chemical action as acting directly on
the bloodvessels or on the dilator nerves which supply
them; but though some such action probably takes
place, it is very doubtful if it be the only factor we
have to consider, for motion in general is preceded
by sensation or by its equivalent, in this case in the
shape of an afferent impulse. Indeed, if we adopt
the view that the dilation of the bloodvessels or the
relaxation of the mucous membrane is the result of
reaction on the part of the vaso-motor and other
centres, we must perforce suppose that they have
received a stimulus from the seat of activity. This
stimulus is a factor which we can by no possibility
get rid of if we admit the existence of reaction. In
one shape or another it must reach the vaso-motor
centre. But if, on the other hand, we suppose the
same fibres to act as carriers of both sensory or afferent
and motor impulses, or at least as discharging the dual
function, we must imagine a dilating vibration to pass
from the affected bloodvessel along the dilating fibre
until it reaches the nerve-cell at the end of it, which
would then take up the peculiar vibratory rhythm,
adding force to it and thus reacting. That this course
of events does not represent that which happens in
some cases will be demonstrated by an example, but
that it may occur in others is a possibility to which
it is well not entirely to shut one’s eyes.

THE ACTIVE FORCES OF LIVING ORGANISMS 8t

Investigation into the nervous mechanism governing Secretory
the secretory action of the submaxillary gland has chevtitao:
revealed facts which, from the point of view of the nerves in
matters just discussed, are of considerable interest. ae
When food enters the mouth, the extremities of the &@"¢
lingual and glosso-pharyngeal nerves which are con-
nected with taste, the former in the fore, the latter in
the hind part of the tongue, are stimulated.* Asa
result of this, nervous impulses are carried along
these nerves, and finally reach the centres of taste
in the cerebral cortex. What paths they follow and
what connections they set up is as yet but partly
known. Simultaneously, however, other impulses
travel, it is supposed, down the chorda-tympanit
nerve to the gland, and cause a dilation of its blood-
vessels and secretory activity.t The cortical percep-
tion of taste is not the most important part of saliva-
tion, and we must suppose that stimulative impulses
travelling to the centre in the medulla oblongata,§
which governs the secretory process, are in reality
more essential. Considerable doubt exists as to the
true origin of the chorda-tympani nerve. Some look
on it as arising in connection with the fifth, some as
being a branch of the seventh or facial nerve. The
lingual being a branch of the fifth, its relations to the
chorda-tympani would be more easy to explain on the
first hypothesis, but the evidence hitherto accumulated

* Foster, loc. cit., p. 1403. + Ibid., p. 896.
{ Ibid., p. 399. § Lbid., p. 98.
6

Direct
stimula-
tion of the
chemical
processes.

82 THE ACTIVE FORCES OF LIVING ORGANISMS

does not warrant any definite statement. The chorda-
tympani, moreover, is not the only nerve which modifies
the vascular condition of the submaxillary gland. Fila-
ments reach it following the course of the small arteries
and proceeding from the superior cervical ganglion,*
whence they can be traced back along the cervical
sympathetic to the spinal cord, which they enter
presumably by the anterior roots. The function of
these nerves is to constrict the arteries and thus keep
up their tone; but the part which they play appears
to be of less consequence than that of the chorda-
tympani, for section of the former will not prevent
the flow of saliva, whereas when the latter is divided
it ceases, and cannot be started afresh.

Again, experimental evidence tends to show that
the chorda-tympani nerve possesses two sets of fibres,
one of which acts as vaso-dilators, whilst the other—
and this is extremely important—stimulates secretion
in the cells of the gland in a direct manner irrespective
of the blood-supply.t ‘ Hence,’ says Foster in dealing
with this point, ‘ when the chorda is stimulated, there
pass down the nerve, in addition to impulses affecting
the blood-supply, impulses affecting directly the
protoplasm of the secreting cells and calling it into
action, just as similar impulses call into action the
contractility of the substance of a muscular fibre.’
These facts and others of a similar nature relating to
other glands seem to prove conclusively that the

* Foster, loc. cit., p. 14038. Tt Ibid., p. 400.

THE ACTIVE FORCES OF LIVING ORGANISMS 83

nervous system is both acted on by and reacts upon
the electro-chemical processes of metabolism.

At the same time, it must be constantly borne in Relative
mind that the two forms of force, the electro-chemical qa
and the nervous, though convertible, are in a certain fecal

‘ . action and
measure independent of one another. This fact has nervous

been strikingly illustrated in certain cases by the eae _
section of almost all the nerves of the stomach,* which P°!8™
led, contrary to expectation, to no arrest of the
digestive processes, although it is well known that 5
with the nerves intact under conditions of emotional

stress or impaired health the chemical action of the
stomach is frequently very much disturbed. If we

keep these conditions of independence well in view we

shall see that we are not justified in concluding that,
because digestion will go on after section of most of

the nerves, there are none possessing a secretory
function analogous to that of the chorda-tympani.

Why, then, it will naturally be remarked, does section

of the latter nerve cause a cessation of the functional
activity of the gland? But if we look deeper into the
matter we shall notice that the conditions in the
stomach and submaxillary gland, though analogous in

many respects, are not so in others. In the former Difference

‘ é a 4 between
case, the materials to be digested are directly in contact secretory

with the secreting glands; in the latter case, there is a #¢t#onm

long duct intervening. Therefore there is greater eee
need of nervous action or nervous collaboration in the a
submaxillary gland than in the stomach.
* Foster, loc. ctt., p. 403.
6—2

All nerves
and nerve-
cells are
concerned
in chemi-
cal action.

84 THE ACTIVE FORCES OF LIVING ORGANISMS

It will be well, however, to recall a statement which
we made when discussing the nature of the nervous
impulse. It was then pointed out that oxidation of a
nerve-cell or of a collection of nerve-cells is the very
essence of nervous action, at least, under normal
conditions. It will be seen, therefore, that to this
extent every nerve-cell in the body is concerned in
chemical action or metabolism. But we may go even
farther, for we may say that no action of any kind
whatsoever takes place in any organism which does
not lead either directly or indirectly to oxidation in
the active part. If you do but press with your finger
on the palm of your hand, you cause a temporary
decrease in the rate of oxidation followed when
reaction takes place by a proportional increase. It
you lift a heavy weight from the ground, chemical
action of an intense kind occurs, and in both instances
it is governed by the nature of the sensory nervous
impulses and their motor reaction. We must, there-
fore, perforce arrive at the conclusion that every nerve-
cell and every nerve-fibre in the ordinary course of
functional activity helps to regulate the processes of
metabolism in the part it supplies. With respect to
that metabolism which takes place in a state of repose,
and in which the anabolic tendency is, there seems
reason to suppose, especially marked, we may also
believe that it is under nervous control, the latter
being modified by the conditions which have existed
during functional activity. How important the
metabolism of repose is for the building up of nervous

THE ACTIVE FORCES OF LIVING ORGANISMS 85

matter which contains relatively but little oxygen has
already been pointed out, and it would seem that a
real gain in this respect can only be brought about
when oxidation goes on after each fresh stimulus in a
slightly decreasing rather than increasing manner.

In the effects produced upon the nervous system
by sudden variations of temperature one may obtain
further evidence, though of an indirect kind, of the
modification which the state of contraction or ex-
pansion of parts of the nerve-cells undergoes as the
nervous rhythm varies. The contracting influence
of cold and the expanding influence of heat, it is
scarcely necessary to say, are by no means limited to
physiological processes, for with the exception of
liquids in a freezing state, which are probably not
true exceptions, all substances, whether organic or
inorganic, are affected by them in the same way,
though in different degrees. The molecules of living
organisms behave, therefore, very much as do those of
a piece of copper or iron; they separate under the in-
fluence of heat, though of course much more readily,
and they draw together under that of cold. When
the whole cutaneous surface of the body is suddenly
exposed to the influence of cold, as in a bath, there is
a general movement of contraction. That this move-
ment is mainly vaso-motor may be granted, but that
it is limited to the bloodvessels is apparently the
case. The phenomenon known as goose-skin shows
that muscular, and probably other elements such as
the nerve-endinys, take part in it. If the latter are

86 THE ACTIVE FORCES OF LIVING ORGANISMS

directly affected, then it is natural to assume that the
nerve-cells with which they are connected are in-
fluenced in a similar manner, that the rhythm of
their metabolism is suddenly altered, and that the
molecules of which their protoplasm is composed,
though still continuing to vibrate, are grouped in
closer order. Indeed, if cold, like heat, be, as it is
generally held to be, a distinct form of active foree—
and this view receives support from the phenomenon
of freezing—it is but natural that it should act
upon the nervous system dynamically; and if this be
allowed it is difficult to conceive any other way in
which it can act than that just suggested. If the
arterial blood-pressure be normal, the contraction
caused by the sudden application of cold will be
accompanied by a diminution of oxidation in the
nerve-cells even when allowance is made for anything
in the way of added tone to the arterial system, and
the expansion caused by heat will be accompanied by
a corresponding increase of oxidation when in the
same way allowance has been made for the more
relaxed state of the arteries.

A cool or cold bath, when there is no reaction, may
be said to produce a general effect of peripheral con-
striction and a diminution of oxidation in the nervous
system, and thus throughout the body. To obtain
this result it is employed in cases of fever. In this
way the metabolic rhythm of the nervous system is
altered, and it is brought from a state of excessive to
one of diminished oxidation, and at the same time

THE ACTIVE FORCES OF LIVING ORGANISMS 8&7

from a condition of constant loss, since in fevers the
breaking down of tissue exceeds the building up to
one of equilibrium, and eventually to one of gain;
indeed, the change of rhythm is sometimes of so
decided a character that a person may become very
much stronger a little time after an illness than
before the attack. We therefore see that a certain
degree of contraction in the nervous rhythm is abso-
lutely essential to anabolism, for contraction in this
case is synonymous with attraction. We can very
easily bring about a certain degree of contraction in
the nerve-cells by the simple application in one form
or another of cold to part or to the whole of the skin,
and this is a point of great importance. But it is
not all, for in so doing we run a risk of producing a
marked tendency towards stagnation. We pass from
a state of excessive metabolic action to one of in-
sufficient action. The nervous metabolic rhythm,
after having been on the side of excessive expan-
sion, reverts to that of excessive contraction, and
the body, after having expended its forces in riotous
living, is suddenly pinched and starved like that of
the prodigal. In the hyper-contracted state the
nerve-cell does not possess that amount of mobility
which is essential to the maintenance of vital energy
at its maximum. On the other hand, if the nerve-
cells be allowed to fall back into a rhythm charac.
terized by too great expansion, there will be a loss,
both of energy and, a perhaps more important matter,
of actual material or tissue, The. general aim, in,

88 THE ACTIVE FORCES OF LIVING ORGANISMS

nervous treatment may therefore be defined as being
to make the state of contraction predominate slightly
over that of expansion, and to stimulate nervous
mobility chiefly within the limits of the former.
When a cold bath is followed by a sharp return of
blood to the skin a double effect is produced, for a
note of contraction and diminished oxidation is
struck, succeeded immediately by one of expansion
and increased oxidation. The nervous metabolic
rhythm acquires under these conditions a dual
character, with an increased tendency in both direc-
tions, but mainly, it would seem, towards contraction.
In those whose nervous system is well balanced the
normal rhythm is soon re-established. Those, how-
ever, the protoplasm of whose nerve-cells has been
constantly contracted and expanded in an exaggerated
manner through indulgence in alcohol, or through too
free consumption of food-stuffs, or medicaments con-
taining alkaloids, or through repeated and intense
increases and decreases of oxidation caused in other
ways, or, again, through hereditary tendencies due
to the heavy drinking habits of parents or an-
cestors, such persons will naturally be influenced
in an excessive degree by the cold bath. In young
people, when there is excess, it is generally on the
side of contraction, whilst in old people the reverse is
sometimes the case. One of the commonest results
of treatment in the way just described is to produce
cold hands and feet. This illustrates the mode of
action of the bath in such cases, for we have clear

THE ACTIVE FORCES OF LIVING ORGANISMS 89

evidence of both vaso-constriction and diminished
oxidation. Severe indigestion is also frequently due
to a similar state of excessive vaso-constriction and
diminished oxidation, and habitual sleepiness may be
attributed to the same cause. Amongst the signs of
relaxation, due to a predominance of the expansive
tendency, are hot hands and feet, insomnia, and con-
stipation.

In respect to the influence which a cold bath with
a marked reaction may exercise through the vaso-
motor centres, the first point to consider is the
continuous character of vaso-motor action. Each
beat of the heart causes movements of expansion and
contraction in the whole arterial system which are
intensified by the bath. That this pulsation is lost
before it reaches the capillaries and tissues is well
known, so that it is impossible to trace any direct
effect on metabolism in this direction. On the other
hand, however, it is perhaps not impossible that a
dynamic effect may be produced upon the whole
nervous system, owing to its relations to the vaso-
motor centres, in which case the character of the
metabolic processes would be affected. But whether
the nervous system, and with it metabolism in general,
be influenced by heat and cold directly or only through
the medium of vaso-motor action, the effects produced
on the one are felt in like manner in the other.
Constriction of the bloodvessels, in any part if at all
excessive, as in the case of cold feet, must inevitably
be accompanied by a corresponding diminution of

90 THE ACTIVE FORCES OF LIVING ORGANISMS

oxidation. This is chiefly important because of the
relation which anabolism, or the building up of tissue,
bears to the general state of contraction of both the
arterial system and the tissues, together with the
nervous metabolic rhythm. If the arteries, instead
of being normally contracted, are too relaxed, the
tissues coming under the same general influence will
be too relaxed, and the metabolic rhythm of the
nerve-cells on which the metabolism of the tissues
depends will be too relaxed also. The holding power
of both the tissues and the nerve-cells will therefore
be diminished, and metabolism in them, though
not wholly katabolic, will nevertheless incline to
the side of katabolism rather than to that of
anabolism.

If we admit that expansion and contraction are
essential elements in metabolism, either owing to the
relations existing between the vaso-motor centres and
the rest of the nervous system, or for reasons of a
more direct nature, we may compare nervous action
in general to the behaviour of a piece of elastic band
at rest or under tension. You cannot make the band
contract unless you have previously stretched it; but
the more you stretch it, especially if you overstretch
it, the less forcibly in the end will it contract. By
degrees, as it becomes worn out, it will appear drawn
together and crinkled, and is weak and limp. So it is
with the nerve-cell. At first, we may suppose, it is
well filled and plump, but by intense vibratory action
accompanied by an excessive blood-supply, which is

THE ACTIVE FORCES OF LIVING ORGANISMS 91

the same as the overstretching of the elastic band, it
loses substance, and with it elasticity. In this way
the rhythm of the cell becomes like the state of the
elastic band, sometimes too contracted and sometimes
too relaxed. At the same time it will be understood
that, in speaking of the contraction and expansion of
the nerve-cells, only that degree is implied which one
would suppose to be necessary to produce a change of
rhythm going on amongst the molecules of the cells,
and without which, indeed, such a change is incon-
ceivable. The more highly pathological the nervous
rhythm is, the greater must be the degree of contrac-
tion or expansion in the tissue of the nerve-cell.
Though under normal conditions it is doubtless very
slight, yet it must always be an essential factor in
nervous action.

It will be evident to everyone who reflects for a
moment that, if contraction and expansion are the
very essence of vaso-motor action—and hence of the
activity of the vaso-motor centres—any drug which
acts upon the latter must increase the tendency in
one direction or the other. It may cause increased
contraction for a time, and then give rise to a reaction
of increased expansion when it ceases to act; but in
so doing it must diminish somewhat the equilibrium
between these opposite tendencies, and it cannot bring
about that alternate movement from one state to the
other which takes place with every beat of the heart,
and on which, as a great physician has said, the
health of the whole arterial system depends. Nor

92 THE ACTIVE FORCES OF LIVING ORGANISMS

can you obtain this result by any combination of
drugs of opposite tendencies, for they must one and
all modify the environment of the nerve-cells, and
thus alter the character of their rhythm, acting on
them simultaneously, and not, as would be necessary
if they were to promote general vaso-motor activity,
alternately. By means of a cold bath with a certain
amount of reaction it is possible to bring about both
contraction and expansion, although it is difficult to
regulate the degree of each. By means of rapid
changes from a warm to a cooler bath, and vice versd,
one can stimulate both vaso-motor action and meta-
bolism. The influence of such baths, however, is very
powerful, and aithough under certain conditions it
may be highly beneficial, yet at the same time it may
also be the reverse. If by this means metabolism is
set going very rapidly, it is absolutely essential to
control the general tendency of it—to keep it, that is
to say, with the balance slightly on the side of con-
traction and anabolism. One cannot put the matter
more truly than by comparing the process to the
riding of a bicycle. The short movements of the
handle-bar to this side or that enable you to travel
quickly and smoothly, but unless you pursue a given
direction you will run into the wall or the gutter.
That it is very difficult to maintain a predominance
of contraction over expansion in the arterial system
when it has become thoroughly relaxed is true, but
at the same time it is equally certain that in this way
only, and by keeping up vaso-motor mobility, it is

THE ACTIVE FORCES OF LIVING ORGANISMS 93

possible to insure an anabolic rather than a katobolic
character in metabolism.

Hitherto we have dealt with the nervous system in
its normal condition, but it is possible by means of
electricity to raise it to a higher state of tension than
usually prevails, and the effects produced under these
circumstances have certain features which are of
interest : they are more intense, and in many cases,
perhaps in the majority, they are the result of re-
action. Llectricity, as has been pointed out already,
has no physiological character of its own, nor can it
transmit any save that which it borrows from such
other agencies as constitute the environment of the
body during the period of electrification. The results
obtained from the use of it may be ascribed partly to
the intense vibration which is caused and to a slight
increase in the tendency to vibrate which remains as
an after-effect, but also in many instances to the
sudden cessation of this vibration, whereby the
character of the nervous rhythm is changed. The
benefit or harm which is likely to result from elec-
trical treatment depends, therefore, much less on the
electricity itself than on the conditions under which
the electrification is carried out. Electricity can, in a
word, give greater nervous mobility for a time, but it
cannot alone determine the character which that
mobility may assume. When electricity is admin-
istered in a bath there are certain factors which
deserve attention. If the temperature of the water
be above blood-heat it is evident that the nerve-cells,

94 THE ACTIVE FORCES OF LIVING ORGANISMS

the degree of tension being raised, will be thrown into
a state of abnormal vibration under an expanding
influence ; and when at the termination of the bath
this influence is, as always happens, suddenly re-
moved, it is only natural that a change in the nervous
rhythm should take place, and that it should be in
the direction of contraction. On the other hand, if
the bath be below blood-heat, the change of rhythm
or reaction would be towards expansion. Owing to
the fact that the nervous system is raised during the
passage of the electric current to a higher state of
tension, the effects produced are likely to be in most
instances of a comparatively more permanent nature
than is the case when a simple bath is taken. The
effect of an electric bath may also be said to depend to
some extent on the state of the blood-pressure in the
nerve-centres as determined by the position of the
body, especially if the electrodes be applied to the
spine or head. Variations of blood-pressure affect a
delicate nervous system even without the application
of electricity. Many persons sleep better on a high
pillow ; many, also, do not enjoy perfect repose when
lying on the back. An increase of blood-pressure in
the nerve-centres causes an increase of expansion and
greater activity, hence the tendency to wake or dream
when one is lying on one’sback. Under the influence
of the electric current these effects are increased, and
accordingly the reaction or change in the nervous
rhythm, which takes place when the current is cut
off, is correspondingly greater. Similar, though still

THE ACTIVE FORCES OF LIVING ORGANISMS 95

more intense results may be expected when a patient,
as doubtless often happens, takes an electric bath
under the influence of a drug. There also seems to
be some reason for supposing that the altitude of a
place may contribute in some measure to the ultimate
effect produced by electrification. For instance, if we
suppose a person to go suddenly from sea-level to a
locality 1,000 or 2,000 feet higher, and to undergo
electrical treatment for some weeks, it is likely that
the nervous rhythm would be considerably influenced
by the diminution of atmospheric pressure, and that
the molecules of the nerve-cells would be tuned in
their movements to expansion rather than to contrac-
tion. When, however, electric baths are taken very
frequently, the intense vibration may, in the long-run,
exert an expanding or relaxing influence which will
outweigh all other influences.

CHAPTER II

THE SPINAL CORD AND THE FUNCTIONS OF THE CERE-
BELLUM

The chief features of the spinal cord—The gray matter—Tracts
in the white matter—Fibres of the spinal nerve-roots—
Their functions and connections—Fibres of the posterior
root—The sensory and motor elements in the cord—The
fine fibres of the posterior roots—Other tracts—Functions
of cells in the anterior horn of gray matter—In the lateral
horn—In the posterior horn—Function of the pyramidal
tracts—An idiolateral pyramidal tract—Of the intermediate
bundle — Of the fundamental groups— Of the posterior
columns— Functional correspondence of elements in the
two horns—Size of nerve-cells and thickness of fibres as
a criterion of function — Increase of impulse-cells — The
nervous factors in the local augmentation of activity in an
organism—Increase in the sensory stimulus is chiefly due
to internal causes—The physiological mechanism of will—
The part of the increase of impulse-cells in involuntary
action—The nature of desire—Points of resemblance be-
tween the cells of Purkinje and those of Clarke’s column—
Opposite views respecting the functions of the cerebellum
—Pathological evidence—Ferrier’s facts—Luciani’s cases—
Ferrier’s views opposed to Luciani’s—Cases of defective
development of the cerebellum—Co-ordination is possible
in the absence of the cerebellum—Secondary centres of
the cerebellar system—The factors in equilibration—The
anatomical elements in equilibration—The cerebellum in
voluntary action—The relationship between parts of the

THE SPINAL CORD AND CEREBELLUM 97

cerebellum and groups of muscles—Anatomical relations
of the cerebellum — Relations of the cerebellum to the
spinal cord—Bechterew’s classification—Brief summary of
the pathological evidence—Development of the cerebellum
—The chemical or nutritive influence of the cerebellum
in equilibration—The cerebellum as a reinforcing organ—
Its relations to the vaso-motor centre—Does the cerebellum
influence chemical action directly ?—Chemical action as a
constant element in nervous activity.

Ir is essential at this stage to call to mind some of qe sonics :
the chief features of the spinal cord. Though, roughly t the ones
speaking, of a circular shape, it is divided like the brain
itself into two halves. This division, which is not
absolute, is caused by an anterior and a posterior
fissure, the latter the deeper of the two, being in
reality a septum or membranous partition rather than
a fissure. Each half is made up of a more or less
central portion consisting mostly of nerve-cells and
a peripheral or external portion composed chiefly of
nerve-fibres. These fibres are divided throughout the
whole length of the cord into three main columns—
the anterior, lateral, and posterior. Issuing from the
cord between the vertebre at slightly irregular dis-
tances proceed on each side the spinal nerves by two
roots, the anterior root passing out from the anterior
horn through the anterior column, whilst the posterior
root divides the posterior from the lateral column.
The spinal nerves are mainly channels of sensory
and motor impulses, and they differ greatly in size in
accordance with that of the parts they supply, those
which are distributed to the arms and legs being very

7

The gray
matter.

98 THE SPINAL CORD AND CEREBELLUM

large, and those passing to the muscles and sensory
surface of the trunk being proportionately smaller.
These conditions are reflected in the cord itself, and
especially in the size of the gray matter, which in the
lower cervical or neck portion—whence the nerves of
the arms proceed—and in the lower lumbar and sacral
portion—whence the nerves to the leg issue—is very
considerable, whilst in the intervening dorsal region
its dimensions shrink to one-half or one-third of
the extent occupied by it in the localities just
mentioned.

The gray matter is divided into a so-called anterior
or ventral and posterior or dorsal horn, to which a
lateral horn is sometimes added, and comprises several
groups of cells which increase, diminish, or disappear
as one passes up or down the cord. Thus, there are
median, central, ventro-lateral, and dorso-lateral
groups. Most of the cells of the ventral horn are
supposed to send fibres into the anterior roots of the
spinal nerves,* the impulses passing along them being
motor either to the muscles or to the bloodvessels of
the body and limbs. The dorsal horn is composed to
a great extent of masses of intersecting fibres termed
the lateral and posterior formations. There is, how-
ever, in addition an important group of cells called
the vesicular cylinder or Clarke’s column. It extends
from the eighth cervical to the third lumbar nerve, at
which points it is interrupted, reappearing, however,
between the second and third cervical nerves, and

* Foster, loc. cit., p. 936.

THE SPINAL CORD AND CEREBELLUM 99

possibly, it is thought, in the sacral region also* and
in the bulb above the spinal cord. These cells, it is
held,+ are not connected with the motor fibres which
go to muscles nor with the ordinary sensory fibres,
although they do receive fibres from the posterior or
sensory roots, as we shall presently see in greater detail.
Besides the three great divisions before mentioned the
white matter is divided into numerous tracts. The 7racts in
posterior column is divided by a septum into the matter.
postero-median and postero-external columns. Sepa-
rated from the last-named by the fibres of the dorsal
root is the cerebellar tract, which, throughout rather
narrow, stretches forward along the margin of the
cord almost to its anterior surface. Between this
and the gray matter lies the crossed pyramidal tract,
whilst following the margin of the cord forward from
the cerebellar tract we have the antero-lateral ascend-
ing tract with the antero-lateral descending tract, and
the direct pyramidal tract at its extremity bordering
on the anterior fissure. Of these tracts, three—the
median posterior, the cerebellar, and the antero-lateral
ascending—are termed ascending to signify that they
are supposed to carry impulses upwards to the brain,
whilst three—the crossed and direct pyramidal and
the antero-lateral descending—are called descending
tracts for a corresponding reason. t

The connections and functions of some of these
tracts are but partly known. Fairly well defined,

* Foster, loc. cit., pp. 956-958.
t Ibid., p. 958. { Ibid., p. 945.
7—2

100 THE SPINAL CORD AND CEREBELLUM

however, is the great crossed pyramidal tract stretch-
ing from the cerebral cortex to the large cells of the
anterior horn of the gray matter of the cord, which
serve to connect it with the anterior roots of the
spinal nerves and so with the muscles of the body
and limbs. The direct pyramidal tract is so called
because its fibres pass down the same side of the cord,
crossing, however, before they make their connection
with the anterior roots of the spinal nerves through
the cells of the ventral horn.* The median posterior
tract is composed chiefly of coarse fibres derived from
the posterior or dorsal root of the spinal nerves, which
to reach it pass through the external posterior tract
lying adjacent to it. This has been said to be the
chief path of sensory impulses to the brain,t but
all physiologists are not agreed on this point. The
posterior roots furnish other fibres, which pass inwards
to the vesicular cylinder{ and other cells of the gray
matter. These are especially interesting, for although
forming part of the dorsal or sensory root, they lead
to cells which, as already stated, are not held to be
sensory in the ordinary acceptation of the term. The
fibres of the cerebellar tract take their origin in the
cells of the vesicular cylinder just mentioned, and
pass up the cord on the same side to the cerebellum.§
It is said to begin rather suddenly at the level of the
second lumbar nerve. In addition to the above tract
the cerebellum by its supreior peduncle receives the

* Foster, loc. cit., p. 962. + Ibid., p. 967.
{ Ibid., p. 950. § Ibid., pp. 962-964,

THE SPINAL CORD AND CEREBELLUM 101

fibres of the antero-lateral ascending tract, which are
derived either from the vesicular cylinder or from
cells adjacent to it.*

The fibres of which the roots of spinal nerves are fect ee
composed are derived from many sources, but it is nerve-
possible to classify them, to some extent, according to ae
the parts which they supply and the nature of the
impulses they carry. When the fibres of the common
trunk are traced along their paths to the periphery,
some are found to end in muscle, some in sensory end
organs or sensory surfaces, and some in the sym-
pathetic ganglia. These latter constitute an important
chain stretching the whole length of the spinal cord
on either side. They are sometimes looked on almost
as a separate nervous system, but this view is only
justifiable in a limited extent. Like the parts which
they chiefly supply they are contained for the most
part in the body cavity, and acquire greater size and
importance in special regions. They have a double
connection with the spinal nerves, the one link being
the white ramus communicans, the other the gray
ramus communicans, which sends a recurrent branch
to the bloodvessels of the limbs.t These ganglia are
connected with the viscera of the body, and as these
are composed chiefly of muscular tissue, of sensory or
chemico-sensory surfaces or membranes with their
glands, and of bloodvessels, it seems natural to
suppose that the functions of the fibres passing
through the ganglia will be motor to the muscular

* Foster, loc. cit., p. 971. tT Ibid., p. 171.

1o2 THE SPINAL CORD AND CEREBELLUM

tissue of the viscera, vaso-motor to the bloodvessels,
and chemico-sensory to the mucous membranes .or
tissues where the chemical processes of digestion and
metabolism are started. Besides the fibres proceeding
from the ganglia of the sympathetic system there are
others which affect the calibre of the visceral blood-
vessels.* Referring to the abdominal splanchnics,
which are mainly sympathetic, Foster says: ‘The
majority of these splanchnic fibres seem to be efferent
in nature, carrying impulses from the central nervous
system to the tissues, some ending in plain muscular
fibres, others in other ways; but some of the fibres
are afferent, and convey impulses from the viscera to
the central nervous system, and it is probable that
some of these begin or end in epithelial cells of the
viscera.’ t

Their Passing now from the common trunk of a spinal

functions : .

andcon- nerve, embracing as it does fibres from the muscles,

ee bloodvessels, and sensory surfaces of, In some cases,
both the limbs and viscera, and in other cases of the
body and viscera, it will be interesting to follow as far
as possible the distribution of the various strands of
fibre in the nerve-roots. The anterior root contains
fibres which proceed to the skeletal muscles and to the
muscular tissue of the bloodvessels, and others which
are said to be secretory.t Whilst some of its fibres
come directly from the large cells of the ventral horn
of gray matter, others can be traced to the small cells

* Foster, loc. cit., p. 172.
+ Ibid, fT Ibid., p. 949.

THE SPINAL CORD AND CEREBELLUM 103

of the same region, others pass towards the dorsal
column, to the lateral column, and by what is termed
the white commissure, to the opposite side of the
cord.* Some of the fibres of the anterior roots are
coarse and some are fine; and it is natural to connect
the former with the skeletal muscles and the latter
with the vaso-motor, secreto-motor, and possibly
secretory functions, and. as Bechterew suggests, with
the muscular tissue of the intestines. The last-named
physiologist quotes Gaskell’s opinion that the fine
fibres of the anterior root are connected with the tract
of gray matter known as the intermedio-lateral, with
the post horn, and with Clarke’s column. The
importance of this lies in the fact that fine fibres
from the posterior root seem to terminate in the
same locality or very near to it.

The fibres of the posterior root may be divided into Fibres of
two or three principal bundles. Of these, one termed terior root,
the median, consisting of coarse fibres, passes into the
external posterior column, and thence into the
postero-median column, carrying, it is thought, a great
proportion of the sensory impulses to the cerebral
cortex. Some fibres also pass to the vesicular cylinder
or Clarke’s column, the large long cells of which
have been observed to be imbedded in fibres.t The
second bundle, called the lateral, is divided into an
intermediate bundle consisting of coarse fibres, which
pass directly into the gray matter of the posterior
horn, and a more external portion, composed of fine

* Foster, loc. cit., p. 949. } Ibid., pp. 934, 935.

104 THE SPINAL CORD AND CEREBELLUM

fibres, which run longitudinally up the cord for some
distance between the posterior horn of gray matter
and the crossed pyramidal tract.*

The distribution of the fibres of the posterior root is
complicated by the fact that on entering the cord they
are seen to divide, one portion running upwards and
one downwards, and, further, by the giving off of
collaterals or branches to other cells in the cord.
Some of the fibres, it will be seen—indeed, the great
majority—are coarse, whilst a smaller number are fine.
Most of the former travel upwards towards the spinal
bulb; some, however, pass to Clarke’s column, whilst
others either join the substantia gelatinosa of the
dorsal horn, or make connections with the motor cells
of the ventral horn, or, again, find their way to the
opposite side of the cord.t

To thread the tangled maze of fibres thus arranged
is a very difficult task; yet one thing seems tolerably
clear—the directions which they take indicate differ-
ences of function. If they do not tell us definitely
what the part of each set of fibres may be, yet they
furnish us with some data on which to base certain
conclusions. Knowing that the posterior root is the
sensory portion of each spinal nerve, and that the
cerebral cortex is the seat of perceived sensation, we
have reason to believe that those fibres which pass
upward towards the spinal bulb, and then by means of
certain relays—as to the nature of which some of the
highest authorities are not agreed—establish a con-

* Foster, loc. cit., p. 949. + Ibid., p. 950,

THE SPINAL CORD AND CEREBELLUM 105

nection with the cortical cells, are very important
sensory channels.

Those fibres which pass to the motor cells of the ae pets

ventral horn and those which cross the opposite side motor
of the cord seem by reason of their connections to be ae
of a co-ordinating nature. They bring, so far as one oe
is able to judge, one part of the nervous system into
relation with another. What, then, is the function of
the remaining fibres of the posterior root, both coarse
and fine? It will be remembered that the anterior
root was said to be composed of motor, vaso-motor,
secretory, and perhaps secreto- motor (to the muscularis
mucose) fibres; and one is the less inclined to look
for a reduplication of any of these in the posterior
root, since it is the sensory root. Motion and
sensation are most closely allied, although distinct ;
and probably in all organisms the former is the
consequence, and, one might almost say, the continua-
tion, of the latter. They represent, as it were, the
wave and counterwave in a vibratory movement.
The whole architecture of the spinal cord, the division
of its gray matter into what one may look on as a
motor and a sensory horn, the distribution of its
white matter and of the nerve-roots in a corresponding
manner—all this seems to be based on the fact of the
anatomical difference between sensation and motion.

But if for this reason one should put aside all motor The fine
impulses, excluding at the same time any which might the pos-

be termed purely co-ordinating, and those which are roots.
sensory in the ordinary sense, and are believed by

106 THE SPINAL CORD AND CEREBELLUM

some physiologists to follow a direct path to the bulb,
the question again presents itself, What may be the
function of the remainder which are connected with
cells in and around the posterior horn? The anterior
horn is, one may believe, mainly motor. Is the posterior
horn merely a centre of co-ordination, or is it mainly
sensory? If it be sensory, are not the fibres which,
proceeding from the posterior root, end in it also
sensory? Again, if they be sensory, what form of
sensation can we allot to the coarse and what form
to the very fine fibres? Does it not seem likely that
the latter are connected with some of the more delicate
chemical processes of metabolism? The visceral nerves
in general are remarkable for their delicacy of calibre,
and if a portion of their fibres are connected with
vaso-motor functions, and a portion with secretory
or chemical processes, those belonging to the latter
category might be supposed to be of very fine structure.

The circulation of the abdominal region is remark-
able, not only because of the plentiful supply of blood-
vessels, but because the variations to which it is subject
are probably greater than in any other part of the
body. The nerves of the intestines must for this
reason include many vaso-motor fibres, and their
distribution on reaching the cord must correspond,
one would suppose, in some measure to the position
occupied by these organs. Although the distribution
in the spinal cord of the abdominal splanchnics or
vaso-motor nerves to the intestines is a matter of
great complexity, one may probably assume that they

THE SPINAL CORD AND CEREBELLUM 107

make connections in the spinal cord in the lower
dorsal and lumbar regions.* If in addition to vaso-
motor fibres these nerves constitute paths for secretory
or chemico-sensory impulses, then we should have the
two presumably essential factors in nutrition, and we
might reasonably infer that this portion of the cord
is in a special manner connected with functions of
this order. As regards the lumbar portion of the
cord, there is, indeed, distinct evidence that it is
functionally concerned in keeping up the nutrition
of certain parts of the body; for when in a dog it is
severed from the rest of the cord, but otherwise left
intact, the animal may, if carefully treated, be kept
alive and in very fair condition, whereas if the lumbar
section be not only separated but destroyed, the
nutritive processes, especially in the hind limbs,
become disordered and death ensues.t Bed-sores
and impaired nutrition are also frequently the conse-
quence of injury to the spine.t This seems to indicate
that there are certain cells in the cord itself which
play an essential and important part in the nutrition
of the body. That some cells in the lumbar portion
are specially concerned in keeping up and giving power
to the other nerve-cells is certainly suggested by the
satisfactory state of nutrition after separation. From
the above facts and from the anatomical relations of
the abdominal splanchnic nerves to the cord one would
be inclined to infer that somewhere in the lower dorsal

* Horsley, ‘The Brain and Spinal Cord,’ p. 116.
+ Foster, loc. cit., p. 986. t Ibid.

Other
tracts.

108 THE SPINAL CORD AND CEREBELLUM

or lumbar portions important centres are to be found
for the digestive and renal organs.

This carries us one step further, but here our diffi-
culties really begin. We may be able to specify the
kinds of impulses which are likely to proceed from
the digestive organs by analyzing the various forms
of action of that region. We may group them with
reference to their course by the motor and sensory
roots of the spinal nerves with at least a certain
degree of probability; but when we enter the spinal
cord itself, and seek to trace the paths they follow
and the nerve-cells with which they are connected, we
tread upon ground where exploration, though actively
pursued, has as yet yielded but, comparatively speak-
ing, few definite results.

In addition to the direct and crossed pyramidal
tracts there are a few scattered fibres in the latter of
these, to which the term idiolateral pyramidal tract
has been applied. The reason for this is that a
cerebral lesion in one hemisphere will give rise simul-
taneously to degeneration, not only in the direct and
crossed pyramidal tracts, but in the crossed pyramidal
tract of the same side as the hemisphere affected.*
In the posterior column, besides the outer portion
called Burdach’s column, and the inner portion called
Goll’s column, there is a small tract, more centrally
placed, spoken of as the ‘descending comma tract.’
It is supposed to be composed—at least in part—of the
descending portions of the posterior root-fibres which

* Foster, loc. cit., p. 942.

THE SPINAL CORD AND CEREBELLUM 109

branch as they enter the cord, and as these portions
are short, degeneration when it occurs is limited in
extent. Both Burdach’s and Goll’s columns are said
by Bechterew to contain many fibres which do not
pass directly to the medulla oblongata, but at successive
levels form connections with the gray matter of the
cord.* In the external posterior tract close to the
point where the posterior roots enter the cord, there
is a further subdivision of the posterior column, called
the posterior root-zone, the fibres of which pass almost
directly to the gray matter of the cord, and in addition
to this there is a small zone of very fine fibres, called
Lissauer’s zone, lying close to the tip of the dorsal
horn, and owing its origin also to the posterior root.t

* Bechterew, ‘Die Leitungsbahnen im Gehirn und Riicken-
mark,’ pp. 58, 59: ‘Es ergiebt sich hieraus der Schluss, dass
die zarten Strange vorwiegend aus langen Bahnen bestehen,
welche zum grossen Teil ununterbrochen bis zu den gleich-
nimigen Kernen der oblongata emporsteigen, dass die Keil-
strange hingegen der Hauptsache nach ein Gefiige kiirzerer
Fasern darstellen. Beide Stringe enthalten iibrigens, wie
erwibnt bis zu einem gewissen Grade Fasern von gleichem
Ursprung.’ Page 60: ‘ Riicksichtlich der Lage der Wurzelfasern
in den Hinterstrangen lehren neuere Untersuchungen, dass jede
neu eintretende Wurzel stets lateralwarts von den bereits ein-
getretenen zu liegen kommt und letztere medianwiarts verdrangt.

Hierbei ist nicht zu vergessen, dass in den proximalen
Teilen des Markes iiberhaupt nur wenig Fasern aus distalen
Gegenden zu treffen sind; die Mehrzahl der letzteren biegt
schon vor Erreichung der oblongata in die graue Substanz um,
und von hier gelangen dann in die Hinterstrange weitere Fasern,
welche offenbar die in der grauen Substanz unterbrochenen
Hinterwurzeln centralwarts fortzusetzen bestimmt sind.’

+ Foster, loc. cit., p. 945.

110 THE SPINAL CORD AND CEREBELLUM

The fact that the cerebellar tract does not undergo
degeneration when the posterior nerve-roots alone
have been severed, but only when the cord itself is
injured,* shows the connection between it and the
spinal nerves to be an indirect one.

The remainder of the white matter of the cord—that
is to say, the greater part of the anterior division and
a considerable part of the lateral division—has been
differently defined by various writers.

The fibres of the antero-lateral ascending tract are
supposed to take their origin in the middle zone of
the gray matter, and often degenerate in company
with those of the cerebellar tract.t Those of the
antero-lateral descending tract, apparently described
by Bechterew and Marchi as the anterior-marginal
bundle, occupy a position parallel and close to those
just mentioned, and are said to be connected with the
cerebellum and to constitute a path for centrifugal
impulses.t Internal to the antero-lateral ascending
and descending tracts and the crossed pyramidal
tracts, between these and the gray matter are the
anterior and lateral fundamental tracts;§ whilst
immediately between the crossed pyramidal tract
and the posterior horn of gray matter is situated
a tract called by Bechterew the median bundle of the
lateral column. According to the same author there
is also a tract of fibres in the centre of the crossed
pyramidal tract which undergo descending degenera-

* Foster, loc. cit., p. 968. + Bechterew, loc. cit., p. 89.
{ Ibid., p. 81. § Ibid., p. 84.

THE SPINAL CORD AND CEREBELLUM III

tion when the inferior peduncle of the cerebellum has
been severed. To these he has applied the term
‘intermediate bundle.’* Of the fibres of the antero-
lateral fundamental tracts, which are sometimes
grouped together, some are connected with cells of
the anterior horn, some through the anterior com-
missure with the posterior horn of the other side—and
especially with the cells of Clarke’s column—whilst
others pass to the gray substance between the lateral
and posterior horns of the gray matter.t
The cells of the gray matter, which are held upon Fuvetions

of cells in

evidence which is fairly conclusive to be motor to the the an-
7 terior horn

skeletal muscles, occupy a position rather to the of gray
external side of the anterior horn, forming what is pares
termed the lateral or limb group. Another group
called the median is situated on the inner side of the
horn towards the anterior fissure, and is especially
conspicuous in the thoracic portion of the cord. It is
said by Bechterew to be composed chiefly of com-
missure cells connected with the opposite side of the
cord.t At the base of the horn and near to the
anterior commissure and central canal is a third
group of smaller cells, also belonging to the same
region, and very scantily represented in the cervical
and lumbar portions. It is held that the median
group is essentially distinct from the lateral group
and there seems to be some reason to suppose that
the latter is not represented, or is represented to a

* Bechterew, loc. cit., p. 97.
+ Ibid., p. 78. { Ibid., p. 25.

112 THE SPINAL CORD AND CEREBELLUM

slight extent only in the thoracic region. Hvidently,
if this be so, the lateral group must differ in function
from the others, and if the median group be as
suggested, commissure cells, it seems natural to
connect the group of smaller cells at the base of the
anterior horn with vaso-motor or secreto-motor

functions.

aes A group of cells has been defined in the lateral

horn. horn which is well marked in the thoracic region, and
is discernible in the lumbar region, but becomes
confused with the lateral group of the anterior horn
in the cervical portion of the cord. This group is
thought to be motor to the intestines.*

In the Two groups, known as the posterior lateral reticular

posterior . 3 -

horn. formation and the lateral reticular formation, occupy

a position about the centre of the posterior horn,
which, roughly speaking, they bisect. They are
found throughout the cord, being most conspicuous in
the cervical region. Near the base of the posterior
horn, on the inner side, is a very important group of
cells already mentioned, viz., the vesicular cylinder
or Clarke’s column. The cells of this group are large
and fusiform. They lie with their long axis length-
ways along the cord, surrounded by, or, as it were,
embedded in, a mass of fibres. This group is very
prominent in the central portion of the cord, extending
from about the eighth cervical nerve to the third
lumbar nerve. It has been recognised again opposite
to the second and third cervical nerves, and is
* Bechterew, loc. cit., p. 26.

THE SPINAL CORD AND CEREBELLUM 113

supposed to be present in the sacral region and in the
medulla oblongata.* The region of its greatest
development is the lower dorsal and upper lumbar.
The axons or main fibres of these cells are coarse, and
pass, as stated, to the inferior peduncle of the cere-
bellum forming the cerebellar tract.

In attempting to determine the functions of the
various parts of the white and gray matter of the cord,
it is necessary to consider, firstly, their anatomical
relations so far as these happen to be known;
secondly, the size of the cells and fibres; thirdly, the
nature of the impulses, chemical, sensory, or other-
wise, which may constitute a part of their environment ;
and, fourthly, the character of the degeneration they
undergo after section or in pathological cases.

By a very general consensus of opinion the direct Function
and crossed pyramidal tracts have been set aside as pyramidal
the chief, if not sole, paths of motor impulses to the
skeletal muscles. They both end by forming arbor-
escences round the large cells of the anterior horn.t
The fibres of the direct tract} are said to cross by the
anterior commissure, but this has been denied.§ The
united pyramidal tract as it passes down through the
lower parts of the brain from the cortex of the

* Foster, loc. cit., p. 957.

+ Recent research, I have been informed, has revealed a con-
nection between the pyramidal tracts and the cells of Clarke’s
column.

{ Foster, loc. cit., p. 962.

§ Bechterew, loc. cit., p. 94: ‘Der vordere Pyramidenstrang

hat demnach Beziehungen zu Nervenzellen des gleichseitigen,
nicht aber zu solchen des entgegengesetzen Vorderhornes.’

8

The idio-
lateral
pyramidal
tract.

Of the
inter-
mediate
bundle.

114. THE SPINAL CORD AND CEREBELLUM

cerebrum to the pyramid makes connections with
several cranial nerves, whilst its fibres also give off
collaterals to form similar connections in the spinal
nerves.* These connections may be held to constitute
part of the co-ordinating system of the body, whereby
the muscles are brought into functional relations with
the sense organs and with one another.

The function of the remaining tracts of fibres which
are intimately connected with or which form part of
the pyramidal system is more difficult to determine.
One of these, the idiolateral, occupying, it will be
remembered, the same position in the cord as the
contra-lateral fibres of the crossed pyramidal tract,
and being mingled with them, undergoes degeneration,
according to Foster, when a lesion occurs in the
hemisphere of the same side. The other, described by
Bechterew as occupying a position in the crossed
pyramidal tract almost identical with that of those
just mentioned, degenerates when the inferior peduncle
of the cerebellum is severed. It consists, indeed, of
the group of fibres termed the intermediate bundle or
tract, which, proceeding from the cerebellum, join
the pyramidal fibres in the medulla oblongata.
Severance of the inferior peduncle, however, not only
leads to degeneration in their fibres, but also in the
crossed pyramidal fibres of the same side, and even
in those of the anterior roots of the spinal nerves.t+

* Foster, loc. cit., p. 961.

+ Bechterew, loc. cit., pp. 96, 97: ‘In der Pyramidenbahn
sind, wie ich unlingst nachgewissen, zerstreute Fasern ein-
gelagert, welche einer etwas friiheren Entwickelungsphase

THE SPINAL CORD AND CEREBELLUM 115

Considering that the fibres of the ‘intermediate ’
bundle, like those mentioned by Foster, are described
by Bechterew as scattered, that, like them, they
undergo descending degeneration and coincide with
them in position, it is difficult to look on them
otherwise than as identical. But Bechterew speaks
of the bundle as consisting of fibres which do not
degenerate as a consequence of cerebral affections.
Foster mentions degeneration on both sides of the
cord as the result of cerebral lesions in one hemi-
sphere. Bechterew, on the other hand, speaks of
double degeneration on one side only, in the inter-
mediate bundle, that is to say, and in the crossed
pyramidal tract, as resulting from severance of the
inferior peduncle of the cerebellum. If the latter
conditions represent a functional relation between

entstammen. Dieselben gehéren einem ganz selbstindigen
System an; denn bei Degeneration der Pyramidenbahn nach
Gehirnaffektionen findet man stets eine Anzahl nicht degene-
rierter Fasern, die mit jenen dlteren Elementen der Pyramiden-
strange allem Anscheine nach identisch sind. Sie entsprechen
meines Erachtens in allen Stiicken dem mittelst der Degene-
rations — methode aufgefundenen intermediéren System von
Lowenthal und kénnen daher mit Recht als intermediires
Biindel zusammengefasst werden. Die in Rede stehenden
Fasern haben ihren Ursprung im Kleinhirn und gesellen sich
im verlangerten Marke zu den Pyramidenbahnen. Dies erhellt
einerseits aus dem Umstande, dass sie proximal von der Briicke
nicht mehr angetroffen werden, anderseits zeugt hierfiir die
Thatsache, dass nach halbseitiger Entfernung des Kleinhirns
u. a. absteigende Entartung homolateraler Pyramidenfasern
und sogar vorderer Wiirzelfasern beobachtet ist.’ Marchi
Riwvista Sperimentale di freniatria, xiii., 1883.

8—2

116 THE SPINAL CORD AND CEREBELLUM

these two tracts, it is difficult to see why the degenera-
tion should be on both sides of the cord when it
is started in the cerebrum instead of the cerebellum,
although the absence of degeneration in the fibres of
the idiolateral group on the opposite side to the
lesion in the hemisphere remarked by Bechterew
would agree with the facts as related by Foster.
Whatever may be the explanation of these apparently
contradictory facts, it is noteworthy that severance of
the inferior peduncle or removal of one-half of the
cerebellum causes degeneration on the same side in
the pyramidal tract and anterior roots of the spinal
nerves; for this certainly seems to suggest that the
cerebellar system may be concerned, to some extent,
in keeping up the nutrition of the larger or cerebral
system, and it will be seen later on that this fact

does not stand alone.
Of the As to the functions of the fundamental groups of
mental _ fibres, the anterior and the Jateral, very little can be
re definitely asserted. Some of the fibres of the anterior
portion have been traced to the posterior horn and
Clarke’s column of the opposite side, some to the
anterior, and some to the lateral horn of the gray
matter. The fibres of both portions are for the most
part short, and run up and down the cord in branches
or arborescences round motor or other cells.* The
* Bechterew, loc. cit., p. 81. Page 78: ‘ Weiterhin ist in den
Vorderstrang Grundbiindeln ein Fasersystem enthalten, welches
unter Kreuzung seiner Elemente durch die vordere Kommissur

hindurchgeht und in Nervenzellen des Hinterhornes und ins-
besondere der Klarkeschen Saulen wurzelt.’

THE SPINAL CORD AND CEREBELLUM 117

greater part of the lateral column has been said to
carry impulses to and fro between the local me-
chanisms below immediately connected with the
several spinal nerves and the brain above.* The
lateral horn is most conspicuous in the thoracic and
lower cervical regions, and it is precisely in this
portion of the cord that the lateral columns undergo
a decided development, whereas the anterior columns,
on the other hand, are greatly diminished. The
fundamental lateral column is believed to constitute
a path whereby impulses of touch and pain pass up
the cord to the brain.t
Although physiologists generally agree that the ca

posterior columns constitute a great path for sensory columns.
impulses, yet in this case again, as in that of the
fundamental columns, it has been found impossible
hitherto to fix with anything like certainty the func-
tions of the various parts of which they are composed.
Portions of the median column have been found to
correspond to the nerve-roots of the various sections
of the cord, the sacral, lumbar, and thoracic occupying
a position internal to the cervical. It has also been
noticed that severance of the posterior column in
animals produced no analgesia.{ This fact has led
to the conclusion that the columns in question are in
reality channels for muscular sensibility. There are,
however, certain fibres in Goll’s column finer than
the rest, which, by reason of their more slender calibre,

* Foster, loc. cit., p. 959.
+ Bechterew, loc. cit., p. 106. t Ibid.

18 THE SPINAL CORD AND CEREBELLUM

appear to differ in function. Besides the fibres of this
column, derived from the posterior roots of the spinal
nerves, others are said to join it from the cells in the
posterior horn of the gray matter, some of them
proceeding from Clarke’s column.* The fibres in
Burdach’s column are for the most part thick.t
Although certain fibres of the posterior columns con-
stitute an uninterrupted path for sensory impulses
to the medulla oblongata, others, which are very
numerous, pass into the gray matter of the cord at
various levels,t the former being said to be chiefly
fine, the latter principally coarse fibres.§ If we admit
Bechterew’s view that the posterior column carries
only impulses of muscular sensibility, we have still
to account for the difference in calibre between the
two sets of fibres. Moreover, if the impulses of
muscular sensibility from the skeletal muscles pass
along the posterior column, what may be the path of
similar impulses proceeding from the muscular coats
of the intestines? In the usual course of things, we
are not aware of the movements of these organs, but
the conclusion to which this fact leads is that the
sensory system is not in this case connected with the
cerebrum, the great seat of all sensation. The sensa-
tion is unconscious. There seems to be no sufficient
reason for denying the existence of muscular sensory
impulses depending on cells in the spinal cord.
Motion, indeed, is so entirely bound up with sensa-

* Bechterew, loc. cit., p. 37. + Ibid., p. 57.
{ Ibid., p. 60. § Ibid., p. 58.

THE SPINAL CORD AND CEREBELLUM 119

tion that the former is inconceivable in the normal
state without the latter, and we know very well that
the presence and pressure of food in the intestine leads
not directly but indirectly—that is to say, through
the medium of sensation to the contraction which
follows. The latter is evidently of a reflex nature.
In view, however, of the involuntary character of intes-
tinal action, it seems natural to connect the nervous
mechanism of the causative or sensory impulses—
at least, when functioning normally—primarily with
the gray matter of the cord, though a secondary
connection may exist between the latter and the cere-
bellum.
With respect to the functions of those fibres which, Fune-

P : 3 tional
instead of forming part of the posterior column for correspon-

any considerable distance, become almost immediately ce a
connected with the cells of the posterior horn of the j2rne '"°
gray matter, we are again reduced to conjecture.

Were one to look in this locality for cells correspond-

ing from a sensory point of view to well-nigh each
particular kind of cell to be found in the ventral or
motor-horn, we should expect the presence of musculo-
sensory cells to the skeletal muscles, which we should

be inclined to connect with thick or medium-sized

fibres rather than with the very fine fibres distributed

to this locality ; we should, in addition, expect similar

cells to be present to supply sensory impulses by which

the motor activity of the intestines is brought about,

and by which over and above this general movement

that of the mucous membrane is caused in the process

120 THE SPINAL CORD AND CEREBELLUM

of secretion. These, it may be supposed, would be
closely allied to, if not identical with, the chemico-
sensory cells to which allusion has been made. Further,
we should look for some cells connected in at least a
secondary manner with the vaso-motor mechanism.
These, if there be such, and those which contribute
to the action of secretion, we should be disposed to
connect with the finer fibres of the nerve-roots, the
more so since the connections between the sympathetic
system, containing as it does vaso-motor fibres, and
the cord are also of relatively very slender calibre.
Then, again, if the fibres of the posterior columns,
as Bechterew asserts, be not the channel for the con-
veyance of tactile impulses, we should look for cells
constituting an intermediate stage in this process.
This physiologist regards the thicker fibres of the
posterior roots as being paths of muscular sensibility,
the thinner as carrying impulses of cutaneous sensa-
tion.* Are we to understand, however, that under
this expression cutaneous sensibility (Haut Sensibilitdt)
those proceeding from the membranes of the digestive
tract are to be included? Many of the finer fibres
belonging to the lateral bundle of the posterior root
pass, as already stated, to the very centre of the gray
matter between the anterior and posterior horns,+
where they lie in close proximity to the group of small
cells at the base of the anterior horn, and not far
removed from that portion of the lateral horn which
Gaskell regards as being connected with the involuntary
* Bechterew, loc. ctt., p. 48. + Ibid., p. 38.

THE SPINAL CORD AND CEREBELLUM 121

muscle of the intestines. It certainly seems as though
the fine fibres of the motor or ventral root and those
of the sensory or dorsal root were distributed to cells
lying very close to one another.* Near to them also
is the important group of large cells called Clarke’s
column, which, although receiving thick fibres from
the posterior root, is not on that account necessarily
directly connected with muscular sensibility. +

The thickness of the fibres and the size of the cells ee oF
are, as before remarked, factors which cannot be over- and yet:
looked. The two usually go together, and betoken fibres as a
the generation and conveyance of impulses of a certain of oe
and, indeed, of a proportionate degree of force. But sis
where are we to look amongst the various forms of
nervous action for one which could be said to cor-
respond to the celis of Clarke’s column in this respect?
It will be remembered that these cells have been
described as large and fusiform, and as being em-
bedded in fine fibres. ' This interlacing of fibres, so as
to surround a nerve-cell with which they come in
contact without being in absolute continuity, is a
noteworthy but not exceptional feature of the nervous
system. To a greater or less extent it obtains in
many regions. When, however, the fibres are espe-

* Bechterew, loc. cit., p. 44.

+ Foster, loc. cit., p. 958: ‘It seems natural to infer that the
cells forming this vesicular cylinder are connected neither with
the ordinary somatic motor fibres governing the skeletal muscles
nor with the ordinary afferent sensory somatic fibres coming

from the skin and elsewhere, but in some way with some special
sets of fibres.’

Increase
of impulse
cells.

122. THE SPINAL CORD AND CEREBELLUM

cially numerous, as they are in this instance—and as
they are in, perhaps, an even more marked degree
in the cerebellum—when they, so to speak, envelop
the cell, as in Clarke’s column and in the case of
Purkinje’s giant cerebellar cells—there is evidently a
special meaning in this mode of distribution. The
large cells thus enwrapped occupy a central position :
they must perform a central function. When they
vibrate, the intensity of vibration of all the smaller
cells connected with them is suddenly increased. The
conditions which we have before us do not admit of
any other interpretation. The large cell may send
forth its impulse along its main fibre or axon, but as
goon as it becomes active the smaller cells with which _.
it is connected must necessarily vibrate more power-
fully than before. It matters not, indeed, whether
the fibres connecting the latter wiih the former are
afferent or efferent channels, for in the one case the
large cell would, one might suy pose, act as an attrac-
tive centre, whilst in the other event its action might
be of a radiating or propulsive kind. To the large
cells, therefore, on account of/their relations to the
smaller ones, we are justifi¢d in giving the title
‘increase of impulse’ cells.‘

One of the primary conditions of organic life is that
functional activity is never equal throughout the whole
organism. It varies as to place, as to time, and as to
degree or intensity. This condition is so universal,
and so essentially a part of our nature as that of
every other living creature, that we are somewhat

THE SPINAL CORD AND CEREBELLUM 123

inclined to overlook its consequences. Yet it is
undoubtedly a fact that our nervous system must be
fashioned so as to conform to this variability, which
is, as it were, the pivot on which it turns; and were it
possible to create and build up a complicated organism
like our own, it would be incomplete, and it would
not function properly unless full and satisfactory pro-
vision were made for the sudden and forcible trans-
ference of its activity now into one part and now into
another. Within certain limits, the more powerful
such transference is, the more intense, one may say,
will the vital force of the organism be.
As long as breath comes and goes in the body, even The

in a state of the most perfect repose, the whole may factora ia

‘3 : ‘ 7 the local
be said to be undergoing a process of oxidation ; but angmenta-

when passing from the condition of rest certain parts eta
become functionally active, oxidation in them is cae
rendered very much more intense. In this sudden
augmentation of activity three nervous factors come

into play. The first of these is of a sensory, or, it

may be, of a sensory-motor, nature (sensation leading

to motion) ; the second is a vaso-motor one; the third,
intermediate between the other two, an increase of
impulse factor. Both pyschologists and physiologists

agree that the sensory factor is always the primary

one. You cannot will a sensation until you feel it;

you cannot intensify the action of cells representing a
feeling or a thought until they have begun to vibrate.
Sensory impulses vary very much in the degree of

their intensity. We may hear a deafening crash, as

124 THE SPINAL CORD AND CEREBELLUM

we may catch a distant echo. We may see a dazzling
light, or we may observe a faint ray or glimmer, and
the result in one case differs very much from that in
the other. But, nevertheless, one sensory impulse
cannot, or can only to a very slight extent, act directly
as an augmenting influence on other sensory cells.
The augmentation must always, under normal condi-
tions, take place in a reflex manner, through the
‘increase of impulse centre,’ that is to say, and
through the vaso-motor centre. The loudest noise
will frequently lead to no other effect than a temporary
increase in the vibrations of the purely auditory cells.
On the other hand, a whisper in the dark may make
one tremble with anxiety. It is plain, therefore, that
the effect of a sensory stimulus does not depend on its
intrinsic force, but on the conditions under which the
reflex stimulation is brought about. When, however,
many groups of sensory cells—groups representing
feeling as well as sensation pure and simple—are all
vibrating together, the cells on which the reflex
Increase depends are stimulated in a far higher degree, and

ee the general effect is proportionately greater. That

ee produced by cells representing the feelings is always

io internal : :

vauses, more intense, and especially reacts upon the heart;
but what the cause of this may be, whether such cells
are more numerous or whether they receive a greater
supply of blood, no one has as yet been able to deter-
mine.* That the intensity of sensation and of the

* It seems not improbable that our emotions are in reality
due, not to the action of separate ‘emotional’ cells, but to the

THE SPINAL CORD AND CEREBELLUM 125

reflex by which it is brought about does not depend
on the perfect functioning of the peripheral sense-
organ is strikingly proved in the case of Beethoven;
for his symphonies, which constitute in the whole
realm of human production one of the most prominent
examples of intense cerebral action, were composed
after he had become a sufferer from deafness. This
shows that the main faetor in the increase of sensation,
taken in its widest meaning, is an internal one, and
enables us to disregard to a great extent external
influences.

As it is, therefore, evident that all intensification of
sensation is due in the main to an internal cause, it is
necessary to inquire further into the nature of it. It
is a common thing to say of a person who has solved
some very difficult problem, he has worked it out by
an effort of ‘ will.’ This means, if it have any physio-

mode of vibration of the ordinary sensory cells in which vaso-
motor activity plays a very important part. Thus, a condition
of relaxation or of too great expansion of the tissues, including
the nerve-cells, is a fertile cause of melancholy, and can often
be at once removed by the use of such a drug as strychnine,
which stimulates contraction. We see the fruits of this relaxa-
tion and melancholy in the increase in the number of suicides
which invariably takes place when the summer heat becomes
very oppressive. The actual cause of the melancholy and relaxa-
tion is probably to be attributed to a weakening of the heart’s
action and a general diminution of blood-pressure and hence of
oxidation. A sudden change from cold or cool to very hot
weather seems to affect the nerve-centres in an especial manner.
Irritability and excitability may also be traced in a great
measure to causes connected with the vascular system and the
manner in which the processes of oxidation are carried out.

The phy-
siological
mechan-
ism of will.

The part
of the ‘in-
crease of

ras bare
cells in in-

voluntary
action.

126 THE SPINAL CORD AND CEREBELLUM

logical meaning, that in addition to the purely sensory
or intellectual cells others of a different type, which
we may call for the moment ‘ will’ cells, have been
brought into play. But it will be clear to everyone
that ‘will’ cells in this sense must be ‘increase of
impulse’ cells. They must, that is to say, possess
certain attributes or properties which enable them to
intensify the action of other cells, either greater size
and more elaborate branches, or a greater supply of
blood, or something of an analogous nature, by means
of which a sufficiency of force may be generated to
augment the action of the sensory cells. It has
probably never been suggested that the ‘ will’ centre
is identical with the vaso-motor centre; yet the
supposition, though probably not true, is nearer to
the truth than one might be led at first sight to
believe. The ‘increase of impulse’ or ‘ will’ cells
act, one may expect, both indirectly on the sensory
cells through the vaso-motor cells and directly also.
The reflex—for will is certainly a reflex—may be
described thus: Action is started in the sensory
or intellectual cells of the cerebral cortex; it causes
the ‘increase of impulse’ or ‘ will’ cells to vibrate ;
these react on them, and at the same time transmit
a decided stimulus to the vaso-motor centre. The
result is a quickening or intensification of the whole
process of thought or sensation.

The word ‘ will,’ however, is often used in a way
which, physiologically speaking, is not correct, or, at
least, is very liable to cause error.

THE SPINAL CORD AND CEREBELLUM 127

_ There are two elements in volition—a sensory or
intellectual element, and an increase of impulse; but
the term ‘will’ is employed in a vague manner to
cover or express both elements. We should have
a very much clearer conception of things as they are
if we were to keep the two elements separate. We
call the action of the ‘increase of impulse’ cells
‘will’ when they act in conjunction with the sensory
. and intellectual cells of the cerebral cortex, but there
is no reason whatever to suppose that they do not
play a part—an essential and necessary part—in in-
voluntary action also. How, then, are we to designate
the ‘increase of impulse’ cells under these circum-
stances, if our only term for them is ‘ will’ cells?
Doubtless it is true that we have a still further The

conception of voluntary action—a conception, be it ae -
said, which corresponds to certain physiological con-
ditions, but not to any specific class of nerve-cells.
When we have a desire or longing, however ardent
it may be, the only cells to the action of which we
can attribute it are, in the first place, the sensory
cells of the cerebral cortex, representing the idea and
the emotions connected with it other than will,
assuming that the cerebral cortex is the seat of the
emotions; and, in the second place, the ‘increase
of impulse’ cells, already mentioned, together with
the sensory and vaso-motor cells immediately depend-
ing on them. These ‘increase of impulse’ cells are
not, however, to be found in the cerebral cortex,
where, beyond the cells already mentioned—that is

128 THE SPINAL CORD AND CEREBELLUM

to say, the ordinary sensory cells—there are, probably,
none specifically representing desire or volition.
‘But,’ someone will perhaps remark, ‘I may have
the idea of an act without executing it, or I may
hesitate before performing it; yet when I do accom-
plish it some new factor comes into play, and that
factor is ‘ will.’ In psychological phraseology such a
statement may be correct. Let us examine it physio-
logically. If the sensory cells of the cerebral cortex
alone are stimulated either feebly or violently, we
have the idea or the sensation only; but if, on the
other hand, a connection is established with the
‘increase of impulse’ cells and with the motor cells
of the cerebral cortex, then, in addition, we have
action. Hesitation is due to the stimulation of the
‘increase of impulse’ cells by two groups of sensory
cells, representing two distinct ideas. The factor on
which the existence of a connection between the
sensory and ‘increase of impulse’ elements depends
is association or habit. In some, however, the readi-
ness with which the ‘increase of impulse’ cells
respond to stimulation is far greater than in others,
and such persons are inclined to be wilful and to
have exaggerated views and feelings and reactions.
But any philosophy which is based on the supposi-
tion that, in addition to the ‘increase of impulse’
cells, there are other ‘ will’ cells, or that we have
any means of acting in opposition to the strongest
stimulus, is mere fancy. It lies with us, therefore,
to so order our lives and to so excite our nerve-cells

THE SPINAL CORD AND CEREBELLUM 129

that the strongest stimulus is that which is best for
us and for others. If we do so, we shall have no
cause either to deplore the fact that volition is a
matter of habit and of reflex action, or to regret
having based our moral efforts on a physiological
foundation.

Amongst the many kinds of cells belonging to the

Points of

resem-

nervous system, are there any, we may now ask, the blance

characteristics of which correspond at all to those
one might expect in cells destined to intensify the
action of other cells? We have already drawn atten-
tion to the cells of Clarke’s column, and it is natural
to connect these with the giant cells of Purkinje in
the cerebellum, firstly, because the axons or main
fibres of the former lead to that organ; secondly,
because both sets are imbedded in fibres; and, thirdly,
because, though very large, neither set is motor nor
sensory in the ordinary acceptation of the term.

In order to follow this argument to its logical ©
conclusion, it is now necessary to consider somewhat
in detail the whole question of the functions of the
cerebellum. Current opinions with reference to that
organ may be divided into two categories: there are
those who look on the cerebellum as a reinforcing
organ to other parts of the nervous system—as a
reservoir of force, which may be drawn upon to a
greater or less extent, according to the degree of each
local or temporary need; whilst others see in it
nothing more than a great co-ordinating centre, a
great junction, that is to say, where one part of

9

between

the cells of
Purkinje
and those
of Clarke’s
column.

eee
ws re-
eaecung
the func-
tions of
the cere-
bellum.

Patho-
logical
evidence.

30 THE SPINAL CORD AND CEREBELLUM

the nervous system is brought into connection with
another. These views, the latter of which is now
almost universally held, are not in reality so antago-
nistic or divergent as they might appear to be. If
the cerebellum acts as a reinforcing organ to other
parts of the nervous system, its anatomical relations,
being, as is well known, extremely elaborate, would
naturally imply a very considerable amount of co-
ordination as an essential element in its activity.
Under pathological conditions the absence of this
factor would make itself felt at times, and especially
immediately after an operation, in a somewhat marked
manner. If, on the other hand, the cerebellum be a
great co-ordinating centre, it could only be said to
exert no reinforcing or augmenting influence on the
cells with which it is connected anatomically, provided
the cerebellar cells be of the same size and power as
those on which they react. This, however, we know
is not the case, for the cells of Purkinje are beyond
all question amongst the largest and most powerful
nerve-cells in the whole body ;* and to contend that,
under these circumstances, they do not, when suffi-
ciently stimulated, increase the force of the action of
other cells seems to be the very negation of both fact
and reason.

Although pathological evidence as bearing on the
function of any part of the nervous system must
always be received with a certain degree of caution,

* The diameter of these cells is said to be yg55 to gig of an
inch.—Quain’s ‘ Anatomy,’ p. 313.

THE SPINAL CORD AND CEREBELLUM 131

because of the very complicated nature of the
mechanism we have to deal with, yet a thorough
consideration of the following cases will materially
help to establish the truth of the above statements.

‘When* in an animal—monkey, cat, or dog, for
instance,’ says Foster—‘the whole cerebellum is
removed, and the immediate effects of the operation
have passed away, the condition of the animal is
such as to excite wonder that the loss of so large and
apparently important an organ has brought about so
little change. Its psychical powers do not appear to
be at all impaired or changed; it is as alert and
intelligent as before. Sight, hearing, and the other
special senses seem unaffected. There are no distinct
signs of its cutaneous or general sensibility being
deficient or altered. The most that can be observed
is a deficiency in its movements; these are marked
by a certain amount of what we may for the present
speak of under the general term of ‘‘ inco-ordination.” ’

The same author then relates the results of the
removal of one-half of the cerebellum. This operation
leads to no change in the psychical condition nor in
the development of sensations, but to an abnormal
state of the motor mechanism. If the right half of
the organ be removed, ‘ the animal uses the left side,
and especially the left limbs, more than the right’; it
leans and falls to the right side, and ‘shows by the
character of its movements that the muscles of the
right side are not being worked in a normal manner.’

* Foster, loc. cit., p. 1206.
9—2

132. THE SPINAL CORD AND CEREBELLUM

‘The condition is one not so much of absolute loss
of power as of imperfect action.’ ‘The imperfect
action has been described under the general term
‘inco-ordination,” but has been analyzed, though all
observers are not agreed in this, on the one hand into
diminished power—that is to say, energy of contraction
(parasthenia), which in the dog is most conspicuous
in the muscles of the hind-leg—and on the other hand
into a diminished tone (paratonia) and an unsteadi-
ness of contraction due to the occurrence of small
and rapid though regular tremors (parastasia).’ ‘ Ob-
viously,’ he continues, ‘ there is something wrong in
the nervous machinery for carrying out the move-
ments, and especially perhaps the voluntary move-
ments of the right side.’*

‘“Diseaset of the cerebellum, uncomplicated by
lesions in other parts of the brain, in no way
interferes with psychical powers, and does not in the
least impair sensations, either special or general, but
it does interfere with the action of the skeletal
muscles. The disorder which it brings about—an
unsteady gait, the ‘‘ cerebellar reel,” not wholly unlike
that of drunkenness—is usually described as ‘‘ inco-
ordination,” but so far as it can be analyzed seems to
be of the same nature as that produced experimentally
in animals—the same diminution of power leading to
a difficulty in maintaining the erect posture, the same
diminution of tone and the same occurrence of
tremors have been observed.’

* Foster, loc. cit., p. 1207. + Ibid., p. 1208.

THE SPINAL CORD AND CEREBELLUM 133

Dealing with this question, Ferrier relates many Ferrier's
interesting facts, amongst which the following are
some of the most noteworthy :*

Flourens showed that recovery, even after deep
incisions into the substance of the cerebellum, was
a common occurrence, although complete removal of
the organ in birds was never followed by such
favourable results. In the latter case, whilst life may
be prolonged for several months, the symptoms of
cerebellar lesion are always present.t

Sixteen days after Dalton had destroyed two-thirds
of the cerebellum of a pigeon he only noticed a general
debility and a slight difficulty in recovering itself
when it had alighted from flight. {

Wagner observed complete recovery in a pigeon
which lived for twelve weeks after the removal of
more than half of the cerebellum.

When, however, the corpora dentata were affected,
complete recovery did not follow.§

Still more interesting is a case reported by Luciani, Taeees
in which a dog is said to have survived the almost ~
complete removal of the cerebellum for eight months.
The remainder of the life of the animal has been
divided by that physiologist into three periods. The
symptoms during the first of these consisted in
inflammatory complications, spasms, and an excessive
weakening of the motor mechanism. These he
attributed entirely to the effects of the operation and

* Ferrier, ‘The Functions of the Brain,’ pp. 174-219.
+ Ibid., p. 177. { Ibid., p. 177. § Ibid., p. 177.

134 THE SPINAL CORD AND CEREBELLUM

to the presence of an open, suppurating wound.
During the second period a general amelioration of
the state of the animal took place, although weakness
and unsteadiness of gait remained. This shows that
the weakening of the motor mechanism was not
solely due to the suppuration of the wound. Luciani
concluded that the cerebellar ataxy was caused by the
imperfect tone and insufficient energy at the disposal
of the nervous system governing the muscles essential
to animal life (il sistema nervoso motore dei muscoli
della vita animale).* The third period, embracing
about two and a half to three months, is characterized
by Luciani as one of progressive and rapid general
malnutrition (progressiva e rapida denutrizione gene-
permers rale).t The weight of the animal had fallen from
pease ie 5,090 er. at the beginning to 3,040 gr. at the time of
death, when it was suffering, in addition, from
purulent otitis, catarrhal conjunctivitis, and affections
of the joints. Ferrier, who is opposed to the view
that the cerebellum has anything to do with the
nutritive forces of the body, attributes the impaired
nutrition and death of the animal to the special
diseases above-mentioned. Luciani, on the other
hand, is inclined to regard these as definite symptoms
of malnutrition, due to the loss of an organ intimately
concerned in keeping up the nutrition of the body.t
It would be interesting to know whether after the

* Luciani, ‘Lince Generali della Fisiologia del Cerveletto,’

p. 24.
+ Ibid., p. 25. } Ibid., p. 26.

THE SPINAL CORD AND CEREBELLUM 135

removal of the cerebellum there is any loss of power
in the heart corresponding to that so clearly marked
in the case of the voluntary muscles.

In another case* the cerebellum of a bitch was
completely removed. Four months after the operation
the animal gave signs of ‘heat,’ was impregnated,
and ‘was allowed to survive until she had whelped,
nearly a year after.’ Parturition was regular and the
maternal instincts normal. The general health of
the animal was good, and she had increased in
weight. A small fragment of the right lobe of the
cerebellum alone remained after death, which was
caused by the administration of chloroform. The
motor mechanism was more seriously affected than in
the previous cases, the animal being only able to
move by ‘ butting forward,’ but there were few, if any,
signs of inflammation.

Tt will probably be admitted that the evidence in
the first case is distinctly more favourable to Luciani’s
view than to that of Ferrier. As regards the second
case, there is, perhaps, more room for doubt. It is
true, on the one hand, that the nutritive condition of
the animal was good, that it had even improved, and
Ferrier assumes at once on the strength of this fact
that the evidence of malnutrition in the first case may
be entirely disregarded. With respect to this, how-
ever, certain matters deserve further consideration.
We have spoken of the cerebellum as a centre for the
increase of impulses, but are we sure that it is the

* Ferrier, loc. cit., p. 179.

136 THE SPINAL CORD AND CEREBELLUM

only centre of that kind in the body? Is it not
highly probable that Clarke’s column, which, as we
know, is connected with it anatomically, is a secondary
centre of the same order ?

It has been ascertained that one portion of the
cerebellum may replace functionally other parts which
have been removed, and is it not, therefore, possible
that one part of the cerebellar system may replace to
some extent the cerebellum itself?

For many women—and this may apply to animals
also—the period of gestation is one which is distinctly
favourable to the nutritive processes of the body.
They gain in flesh and in weight, as many can doubt-
less certify from personal observation. The heart
especially undergoes a remarkable increase in size
and power.

The state of the animal in this respect may there-
fore be held to account for its good condition, and
to have counterbalanced any unfavourable influence
which would otherwise have made itself felt owing
to the excision of the cerebellum. But though the
building up process, as regards the whelps, seems in
this case to have run its course, and though the
animal’s system appears to have been favourably

affected by it, there is one point with regard to which

the evidence is by no means clear. ‘The animal,’
Ferrier remarks, ‘having been impregnated four
months after complete extirpation of the cerebellum,
was allowed to survive until she had whelped, nearly
a year after.” Putting the most natural construction

THE SPINAL CORD AND CEREBELLUM 137

on this statement, one would be inclined to suppose
that the period of gestation, instead of being as usual
62 or 63 days,* had been so prolonged as to extend to
many months. In the article to which Ferrier refers
one in connection with this matter} there is the same
obscurity in regard to this point, for no direct mention
of the duration of the period of gestation is made.
It is said, however, that it began about the beginning
of September, and at the meeting of a scientific society
interested in the case it was resolved that the animal
should be allowed to survive until after she had
whelped. She was again examined by the members
of this society in the following April—that is to say,
about four or five months after whelping—supposing
the period of gestation to have been of normal dura-
tion. It is to be regretted that on this point clear
evidence is not forthcoming. But if we suppose the
period of gestation in this case to have been normal,
the main factors in this problem would remain un-
changed, for we are justified in assuming that the
nervous system as a whole controls nutrition; that
the cerebellar system (of which the cerebellum, be it
said, is only a part) exercises an especially powerful
influence in this respect by reason of the large cells
which it contains and of the connections of these cells
with the rest of the nervous system; and that nutrition
is frequently so modified during the period of gestation
that even the removal of the cerebellum may not lead

* Miles, ‘Stock Breeding,’ p. 406.
+ The Alienist and Neurologist, St. Louis, July, 1885.

Cases of
defective
develop-
ment of
the cere-
bellum.

138 THE SPINAL CORD AND CEREBELLUM

to the results which would otherwise follow. In deal-
ing with this subject it is, however, very necessary to
guard against drawing conclusions of too absolute a
nature. Although the nervous system undoubtedly
controls nutrition, yet absorption in the stomach can
still take place when all or nearly all the nerves of
that organ have been cut. If, then, this occurs when
the direct nervous supply of the part in question has
been interrupted, it is not surprising that the nutritive
processes in general should, under favourable con-
ditions, go on for a time in a more or less satisfactory
manner after the removal of the cerebellum; for the
action of this organ, though very powerful under
appropriate stimulation, is nevertheless always indirect.
It does not influence the tissues directly, but only
through the rest of the nervous system. It is essentially
a reinforcing organ, and if it appears to be specially
connected with the muscular system, it is because all
movements require an energetic discharge of nervous
force, the variations of oxidation by which they are
produced being also of an intense nature. At the
same time, the cerebellar system must inevitably react
upon all parts of the nervous system with which it
is directly connected, and in this way on the tissues
corresponding to them.

After having pointed out that cerebellar lesions
in man, especially if extending to the whole organ,
are usually attended by disturbances of equilibrium,
Ferrier proceeds to cite two interesting cases of defective
development of the cerebellum, the one being an

THE SPINAL CORD AND CEREBELLUM 139

instance of complete atrophy, whilst in the other that
organ was represented by a very small portion of the
right lobe only. Alexandrine Labrosse lived to the
age of eleven years. After death, in the place of her
cerebellum nothing but a cyst containing serum was
found. She is described as being physically well
developed and as possessing normal sensory powers.
On the other hand, she was defective in intelligence,
could not articulate distinctly, could not stand until
she was five years old, and at the age of seven had
difficulty in holding herself upright, and often fell.
The other case was that of a girl who died of phthisis
at the age of fifteen. She resembled Labrosse in regard
to her sensory faculties and defective articulation,
besides being somewhat weak in intellect, although
not pronouncedly so. Her muscles were weak, but
she could walk ‘well and steadily.’ The early death
in both these cases, and in one of them the suscepti-
bility to phthisis, may be looked on as suggesting a
lack of vitality or nutritive power.
According to Ferrier, the doctrine of Flourens, that Co-ordina-

Spray: : j , tion is, pos-
the cerebellum is indispensable to co-ordination, is sible inthe

absence of
untenable, for in that case the girl Alexandrine the dere-
Labrosse would have been totally incapable of walk- ;
ing. Of this there can be no doubt, and it seems
very manifest that if the cerebellum is a co-ordinating
centre this function is of a secondary character. Nor
is it possible to accept Ferrier’s suggestion that its
function is primarily to act as an organ of equilibra-
tion, unless we give to that term a much more

140 THE SPINAL CORD AND CEREBELLUM

extended meaning than it usually possesses. If we
do not, how are we to explain the malnutrition and
the loss of muscular power and tone which in a
more or less pronounced form are fairly constant
and sometimes very marked symptoms after extirpa-
tion has taken place? Let us but look at the cere-
bellum as an organ, the primary function of which is
to increase impulses of all sorts, but especially those
in which chemical action is intense, and all our diffi-
culties will fade away and vanish. Little by little we
shall be able to evolve a conception of that organ in
which the co-ordinating, the equilibrium controlling,
and the nutritive aspect of its functions will entirely
harmonize with one another; we shall, indeed, see
that these various factors are absolutely essential and
complementary. We have but to bear in mind a few
very simple truths: firstly, that no marked increase
of impulse can occur without an increase in the
chemical constituents out of which it is generated ;
that is to say, you cannot obtain increased nervous
action, and, above all, prolonged nervous action,
without an increase in the blood-supply to the parts
affected ; secondly, that every increase of impulse
implies directly or indirectly an increase of chemical
action ; and, thirdly, that all voluntary action implies
an increase of impulse, for, as we have already shown,
an effect of will is but the result of the cerebellar and
other ‘increase of impulse’ cells acting in combination
with the sensory or sensory and motor cells of the
cerebral cortex. Since, moreover, maintaining one’s

THE SPINAL CORD AND CEREBELLUM 141

equilibrium is an essentially voluntary act, it follows
that the nervous mechanism by which it is carried
out must of necessity contain voluntary elements.
These, as Foster remarks* in the above passage, are
those which are chiefly lacking after the removal of
the cerebellum. We are, however, so much accustomed
to the sensory and the ‘ increase of impulse’ elements
in voluntary action that the liability to error in this
matter is very great.

It has, moreover, been pointed out that, although the ay
cerebellum undoubtedly contains cells, the property # fhe cate.
of which, by reason of their size, must be to increase en
the impulse of other cells, there are probably others
similar in function, though weaker in the degree of
the force they generate, to be found in the spinal
cord, as, for instance, in Clarke’s column. The
existence of secondary ‘ increase of impulse’ centres
seems, indeed, not one whit less natural than of
secondary sensory or motor centres, and all may
probably be said to depend on the fact that the
nervous system is the result of fusion of separate
elements. The possible existence of several collec-
tions of ‘increase of impulse’ or reinforcing cells is
a factor of great importance, and one which on many
occasions has been entirely overlooked. It gains
some support, moreover, from the fact that the lower
you descend in the animal scale, the less perceptible
are the evil results of extirpation of the cerebellum.
There does, therefore, appear to be some ground for

* Quotation, p. 122,

142 THE SPINAL CORD AND CEREBELLUM

supposing that when the cerebellum is removed,
other allied centres may perform for a time the
functions devolving previously upon it, thus enabling
the creature to prolong its existence under conditions
of diminished vitality.

It is often said that the removal of the cerebellum
leads to no diminution in the psychical powers, and
this statement, presumably, applies to animals. As
bearing on this point, it is necessary to recall the
fact, already mentioned, that sensation is to a con-
siderable extent independent of the will. It should
also be remembered that in the two cases of defective
development of the cerebellum the intellectual powers
were decidedly affected.

eee But in what way is it supposed that the cerebellum
bration. produces effects of equilibration, unless it be by re-
inforcing and increasing the ordinary muscular,
sensory, and motor impulses? Does anyone imagine
that the cerebellum is a special sense organ, having
functions similar to those of the semicircular canals ?
There does not appear to be any ground for such a
supposition. No one, we fancy, has ever spoken of
the cells of Purkinje as sensory cells in that sense.
What, then, are the factors in equilibration ?
Muscular sensations and ocular impressions and
others proceeding from the semicircular canals tell
us, let us say, that we are falling. We recognise
the need of reaction, and, guided by our sensations or
impressions of the kinds enumerated, and by others,
it may be, coming from the soles of our feet and skin,

THE SPINAL CORD AND CEREBELLUM 143

we recover our balance by a violent muscular contrac-
tion. What part in all this does the cerebellum play,
unless it be that of increasing the motor impulse, to
the group of muscles set in motion? or, if we put it
otherwise, what factor is wanting to complete the
process ?

In the cerebellum there are three main elements— The ana-

tomical
the cells of the rust-coloured layer, those of the elements

molecular layer, and Purkinje’s cells. What are the teacin,
functions of these, and in what way did they con-
tribute to the recovery of our balance? Was there

any sensory element in the sequence of nervous acts

which could not be accounted for by referring it to

the cerebrum? Let us suppose that the sensory
elements alluded to above were reduplicated in the
cerebellum : for what purpose would such a reduplica-

tion take place unless it were to borrow force from

the great cells of Purkinje ?

That it could not be for the sake of bringing about
co-ordination pure and simple is evident, for we have
co-ordination in the absence of the cerebellum.*

The will as a factor in this problem is one of such
importance that further inquiry into the part which it
plays in equilibration is necessary. We have already

* Ferrier, loc. cit., p. 181: ‘If the cerebellum were indis-
pensable, according to the doctrines of Flourens, for the co-
ordination of movements, it would be impossible to harmonize
the actual facts of clinical observation with an hypothesis so
formulated; for it should have been impossible for Alexandrine

Labrosse to walk at all if the co-ordinated movements of locomo-
tion were dependent on the cerebellum,’

144. THE SPINAL CORD AND CEREBELLUM

shown that the will, as we frequently use the term,
must consist of two very different elements, viz., a
sensory element, which may take the form of sensa-
tion of a primary kind, or may be so complicated as
to represent an idea or group of sensations, but which
in all cases of conscious action is connected with—nay,
is generated in—the cerebral cortex, and in addition
to this an element by means of which sensation and
nutrition—that is to say, chemical action—are both
ea intensified. The seat of this second element is
soluiary generally supposed to be the cerebral cortex also, and
this has so happened because we are always apt to
connect will with consciousness. But natural as this
connection may be, it by no means implies com-
munity of origin; and a histological examination of
the cortex reveals the presence of no cells (if we
exclude motor cells), to which, as in the case of the
cerebellar cells of Purkinje, we should be justified, by
reason of their size and relations, in attributing a
power to increase the impulse of other cells. And
since, moreover, vaso-motor changes are an essential
accompaniment of all forms of activity throughout
the body, we should expect to find a more or less
close relationship between the ‘increase of impulse’
cells and the vaso-motor mechanism, and that this
does really exist seems the more probable owing to
the proximity and relation of the cerebellum to the
medulla oblongata, the seat of the chief vaso-motor
centre. A curious feature of the cerebellum is the
colouration of the rust-coloured layer. Is this due to

THE SPINAL CORD AND CEREBELLUM 145

pigment, it may be asked, or to a more plentiful
supply of blood than goes to other parts of the
organ? One is also naturally led to connect this
matter with the colouration of the red nucleus,
which is in very close anatomical relationship to
the cerebellum.

Ferrier asserts that the mechanism of cerebellar
co-ordination is essentially independent of conscious-
ness and volition, a statement which, seeing that
voluntary muscular action is almost invariably one of
the chief factors in it, sounds at first rather like a
contradiction in terms. He contends that in many
animals you may abolish both consciousness and
volition by removing the cerebral hemispheres, and
still leave the mechanism of equilibration intact. But
it is evident that if the sensory element is to be found
in the cerebral cortex, removal of the latter or of the
greater part of the hemispheres would leave a most
essential part of the mechanism of volition un-

touched.
That one-half of the cerebellum should correspond The rela-

tionshi
to one-half of the body—nay, more, that individual between
parts of each half should bear a functional relationship eerenellum

: . and groups
to certain groups or sets of muscles, or even to certain of muscles.

movements—is perfectly natural and in accordance

with the ‘increase of impulse’ theory of cerebellar

functions. It also agrees with the fact that when

lesions as nearly as possible symmetrical are produced

on both sides of the cerebellum, the amount of

disturbance of the equilibrium is very slight. This,
10

146 THE SPINAL CORD AND CEREBELLUM

indeed, if taken alone, should be enough to convince
anyone who analyzes the phenomena that the cere-
bellum must of necessity contribute a very great
amount of force to the muscular system ; otherwise,
it may be said, the removal of one-half would not lead
to the spasmodic contractions on one side or in one
direction which are known to occur.

Anatomica The anatomical relations of the cerebellum may

the cere- now be briefly considered. It has been described as
a great junction between the cerebral hemispheres
on the one hand and the spinal cord and spinal
nerves on the other, and it will be seen as we proceed
that there are considerable reasons for believing it to
be connected with every part of the nervous system,
and so with every part of the body.

The cerebellum is connected with the rest of the
nervous system by three pairs of peduncles, the
superior, middle, and inferior. The first-mentioned
take their origin in the nucleus dentatus, in a small
collection of nerve-cells close to it, and in the
superficial gray matter. They leave the cerebellum
in front and to the median side of the restiform body,
and, forming the boundary of the fourth ventricle,
pass forward towards the corpora quadrigemina ; con-
verging and sinking ventrally beneath these they
decussate, and finally end in the red nuclei. Some
of the fibres pass by or through these nuclei, and end
elsewhere. Each of the superior peduncles, however,
through the medium of the red nucleus or in other
ways, forms a- connection with the cortex of the

THE SPINAL CORD AND CEREBELLUM 147

opposite hemisphere.* This connection is supposed
to be of a double nature, permitting the carrying
of impulses in both directions. The antero-lateral
ascending column also contributes fibres to the
superior peduncle, which pass into the cerebellum.
The cerebellar ending of the fibres of the middle
peduncles has been traced in the whole of the cortex
of both lobes, and also in the median portion, or
vermis. Thence they sweep down into the pons,
crossing to the opposite side, and in this case also
conduction is supposed to be in both directions.
Bechterewt divides the fibres of the middle peduncle
into two bundles, a cerebral one and a spinal one, the
former of which takes its course to the upper portion
of the pons, where it becomes connected with the
fibres passing down from the cerebral hemisphere of
the opposite side. The spinal bundle breaks up into
two portions, one passing to the same, the other to
the opposite side of the pons. Through the latter the
cerebellum is connected with the reticular formation,
and with the antero-lateral fundamental bundle of the

cord.t
The connections of the inferior peduncles of the = eens
0. 6 cere-
cerebellum with the medulla oblongata and spinal bellum to
the spinal

cord are numerous and important. Foremost amongst cord.
them is that with the direct cerebellar tract through
the restiform body, which goes to form the great bulk
of the inferior peduncles. It is thus that, as before
* Foster, loc. cit., p. 1210.
+ Bechterew, loc. cit., pp. 894-396, { Ibid., p. 895.
10—2

148 THE SPINAL CORD AND CEREBELLUM

remarked, the cerebellum becomes linked in a direct
manner with Clarke’s column or the vesicular cylinder.
There is a second notable connection with the cuneate
and gracile nuclei, and through them with the
posterior columns of the cord.* Some fibres from
Burdach’s column are described as reaching the
cerebellum through the restiform body.t Many fibres
from the inferior peduncle pass to the inferior olive,
both on the same side and on the opposite side.
This path is said to be a centrifugal one, and to be
composed chiefly of axons of Purkinje’s cells, although
some fibres also carry centrifugal impulses. Further,
there is a connection with the superior olive, partly
through the trapezium and partly direct, a possible
link between the cerebellum and the vaso-motor
centre. By means of the so-called intermediate
bundle a centrifugal path is formed to the pyramidal
fibres, reaching far down the cord. Bechterew also
describes connections between the cerebellum by the
central portion of the inferior peduncle and the
nuclei of the auditory, glosso-pharyngeal, pneumo-
gastric, and fifth nerve ; whilst Foster says: ‘Probably
a path to the cerebellum is present for impulses
flowing inwards along the sensory fibres of the cranial
nerves also—that is, of the cranial nerves generally.’
That the cerebellum is functionally connected with
the third, fourth,"and sixth nerves is apparent, since
when stimulation is applied it leads to movements of

* Foster, loc. cit., p. 1208.
+ Bechterew, loc. ctt., p. 387. { Ibid., p. 385.

THE SPINAL CORD AND CEREBELLUM 149

the eyes, whilst corresponding results follow in the
case of stimulation of those parts of the organ
connected with the spinal accessory, facial and hypo-
glossal nerves.

Bechterew has classified the fibres of the spinal Bech-

P terew’s
cord and medulla oblongata connected with the classifica-

cerebellum according to the direction in which it is aa
supposed that the impulses travel. As centripetal he
regards the posterior column, the direct cerebellar
tract, the cerebellar olive tract, and the ascending
antero-lateral tract; as centrifugal he designates the
cerebellar, superior olive tract, the fasciculus longi-
tudinalis dorsalis, the fasciculus antero-marginalis,
the fasciculus intermedius, and a part of the cerebellar
olive fibres.

It will be seen from the evidence already set forth
that the cerebellum is connected either directly or
indirectly with every part of the nervous system, and
that it is thus most favourably placed to act as a
general reinforcing centre for nutritive and functional

purposes.
It has been related how, with respect to one of the are Batt:
two dogs operated on by Luciani, the loss of the the patho.
ogica.

cerebellum was followed in the one case by marked evidence.
signs of malnutrition, ending eventually in death from
that cause. We have considered the cases of two
girls, the one totally lacking a cerebellum the other
with but a rudimentary fragment, both of whom
showed many signs of weakness, and succumbed to an
early death. We have numerous instances of removal

Develop-
ment of
the cere.
bellum.

150 THE SPINAL CORD AND CEREBELLUM

of that organ from various animals, but not one of
which it can be said that the vital powers were not
lowered, nor which terminated otherwise than fatally
within a relatively brief period. Experimental in-
vestigation also shows that when one-half of the
cerebellum is removed, the pyramidal tract on the
same side, and with it the anterior roots of the spinal
nerves, degenerate.*

The mode of growth of the cerebellum also throws
some light upon its functions. In the infant it is
relatively very small, its weight being, according to the
computation of some authorities, only one-twentieth
of that of the cerebrum, whilst in the adult it is about
one-eighth. The proportion the two organs bear to
one another is not the same in the two sexes; in the
male it is as 1 is to 84, in the female as 1 is to 84.
We cannot decide from these figures whether the
cerebellum is greater in the female or the cerebrum
smaller, but there is authority for the statement that
the increase in size of the cerebellum after the
fourteenth year is greater in the female than in the
male.t Why should this be so? Does it not
correspond, coming as it does at the age of puberty,
with the fact that a greater demand may from that
time be made on the metabolic or building-up powers
of the weaker sex? How also, one may ask, could
the activity of the womb in pregnancy react in so
marked a manner as is the case on the development

* Bechterew, loc. cit., p. 96.
t+ Gray’s ‘ Anatomy,’ p. 728.

THE SPINAL CORD AND CEREBELLUM ISI

of the heart, and sometimes of the tissues in general,
unless it be through the medium of the nervous
control to which these factors are subjected in
common ?

Returning to the muscular portion of the mechanism The chemi-
of equilibration, we meet with fresh evidence, if rightly siarihixe
read, of the nutritive function of the cerebellum. Full of the cere-

‘ s . bellum in
of meaning in this respect are the words of an equilibra-
eminent French physiologist.* ‘Like all the organic ic
properties,’ he says, ‘contractibility has nutrition for
necessary basis. It cannot be accomplished without
influencing the double assimilation and disassimilation
indispensable to the maintenance of the life of the
muscular tissue. Every contraction corresponds to a
more energetic oxidation, to a more active assimilation,
to the formation and the elimination of disassimilated
products. The result is manifested immediately in
the vertebrates by changes in the colour, the com-
position, and the temperature of the blood which
comes from it, which is almost as rutilant as the
fresh and oxygenated blood brought by the artery.
The phenomenon is more marked still in the case of
paralysis, in certain maladies which produce muscular
atony in syncope. The explanation is that muscle, in
its state of rest, is at its minimum of consumption, of
life, of contraction ; it absorbs nothing more than is
strictly necessary to its maintenance.

On the other hand, when the muscle contracts, it
wears itself, it expends itself, it absorbs and eliminates

* Letourneau, ‘ Biology,’ pp. 354, 355 (translation).

152 THE SPINAL CORD AND CEREBELLUM

more. Hence the venous blood which comes forth
from it becomes immediately black.

We know that this change of colouration is the
indication of important chemical mutations. Thus
the venous muscular blood which, in the state of
repose, contains only 6°75 per cent. of carbonic acid
more than the arterial blood, contains 10°79 per cent.
after the contraction.

From the above remarks it will be seen that the
functional activity of muscles is indissolubly linked to
an increase of nutritive activity—to a higher degree,
that is to say, of chemical change. If, therefore, we
are justified in connecting the cerebellum with the
contractile portion of muscular activity, as we certainly
are if we regard it as an organ of equilibration, can
we logically put aside the chemical portion of it and
say, To this the connection does not apply? The
matter will appeal to us more strongly if we reflect
for a moment. The contraction is primarily due to
the motor cells of the cerebral cortex. The part
played by the cerebellum is not—Ferrier has shown
this—save in quite a secondary manner, of a co-ordina-
ting nature.*

Nor can we speak of it as anything else of a tangible
nature, unless it be an increasing or reinforcing
agency, acting through the medium of the remaining
element in muscular activity, namely, chemical change.
If this be true of the muscular system, it is probably
so in the case of all the tissues the nervous supply of

* See p. 133,

THE SPINAL CORD AND CEREBELLUM 153

which is connected with the cerebellum, although it is
easier to recognise the connection in the case of
muscular activity owing to the suddenness and marked
character of the changes.

If the reinforcing influence exercised by the cere- car epee
bellum be due to augmentation of chemical action, xeinforcing
how is this brought about? There are in metabolism, oy
as has been shown, two main elements, the one
sensory or chemico-sensory, the other vaso-motor.
Let us first inquire as to the relations of the cere-
bellum to the vaso-motor centre in the medulla
oblongata. This centre, the most important, though
probably not the only one of its kind in the body,*
has been located by many observers. It is said to
extend from about 3 millimetres above the calamus
scriptorius to within 1 millimetre posterior to the
corpora quadrigemina,t+ corresponding, according to
Dittmar, to the anterior portion of the lateral
tracts, in which are scattered the ganglionic cells of
the upper olive (Van Deen) or the antero-lateral
nucleus (Clarke). According to Bechterew, a well-
marked bundle of fibres passes from the cerebellum
to the upper olive, a portion of them reaching it

* Ferrier (loc. cit., p. 100), in dealing with this point, states
that the bloodvessels depend largely on the spinal centres, the
destruction of which, after that of the centre in the medulla,
causes further dilatation. As authorities he cites: Lister, ‘ Philo-
sophical Transactions, 1858’; Goltz, ‘Archiv fiir Physiologie,’
bd. viii., 1874; Vulpian, ‘Lecons sur l’Appareil Vaso-moteur,’
1875.

t+ Ferrier, loc. cit., p. 100.

154 THE SPINAL CORD AND CEREBELLUM

directly, and a portion through the trapezium.*
fee os This seems to bring the cerebellum into very close
hhae ai connection with the vaso-motor centre, and, when one
considers that its peduncles enclose, so to speak, the
whole of that part of the medulla oblongata to which
vaso-motor functions are attributed, and that within
the same area are to be found the nuclei of almost
all the cranial nerves, it becomes evident that this
portion of the spinal cord is the seat of some of the
fundamental vital processes. One is, therefore,
inclined both on general and on special grounds to
believe that the cerebellum is very closely connected
with the vaso-motor mechanism, and, if there be any
truth in this supposition, it enables us to establish an
important link between the great cells of Purkinje or
‘increase of impulse’ cells and the vaso-motor effects
which always accompany an augmentation of func-
tional activity in any region of the body whatsoever.
Does the Allusion has already been made to the fact that
cerebellum . : :
influence secretory action may be produced in the submaxillary
eg gland by direct nervous stimulation irrespective of
‘directly? Vago-motor impulses, and it has been demonstrated
by Bernard, Heidenhain, and others that the nervous
system exercises a direct influence on secretion apart
from vascular action.t Secretory activity has been
caused even in the sweat glands of amputated limbs, t
whilst violent perspiration is sometimes accompanied
by pallor of the skin, indicating contraction and not

* Bechterew, loc. cit., p. 898.
} Ferrier, loc. cit., p. 88. t Ibid., p. 84.

THE SPINAL CORD AND CEREBELLUM 155

dilatation of the small arteries. If, therefore, the
reinforcing influence of the cerebellum be exercised
through the medium of chemical action, there is a
strong presumption in favour of the view that it
either contains chemico-sensory cells or is directly
connected with those cells and fibres in the cerebral
and spinal systems by which metabolism is governed.
That portion of the cerebellum which it seems most
natural to regard as the connecting-link in these
processes is the molecular and cortical layer, and the
fact that certain portions of it do correspond function-
ally to certain parts of the body gives support to this
supposition.
Although the nervous system, as we have just seen, Chemical

: : . : action as a
undoubtedly exercises a controlling and stimulating constant

influence on the processes of metabolism, yet the (omnt™
opinion is generally held that trophic nerves, the sole **¥#V-
function of which is to act in a nutritive capacity, do

not exist. This requires a moment’s consideration.

On the one hand it would be difficult to extend the
functions of those fibres which govern the secretory
processes in the submaxillary gland, whilst on the

other hand a motor fibre to a muscle is not one whit

less a nerve of chemical action than a nerve, let us

say, to the intestines. Chemical change is, indeed, in

a greater or less degree implied in all physiological
action. The gland builds itself up and breaks down
under the influence of nervous action just as the
muscle does. Probably all nerves are to some extent,

and the great majority are to a very great extent,

156 THE SPINAL CORD AND CEREBELLUM

nerves of chemical action. But the cardinal fact in
the whole problem is the sudden, frequent, diverse
and great variations in the intensity of this chemical
action. This it is which renders a reinforcing organ,
such as the cerebellum undoubtedly is, a physiological
necessity in the animal economy. If we but look at
it in this light we can without any difficulty account
for all that is known concerning it—for its co-
ordinating and equilibrium controlling functions, for
the defective character of these after its removal, for
the possibility of the performance of analogous
functions in its absence, and for the state of mal-
nutrition and death which almost without exception
occur. Should not this suffice to convince us that
the cerebellum is in reality, as just stated, a reinforcing
organ to the rest of the nervous system ?

We have dealt hitherto with nutrition, and from this
part of our subject we now pass to consider briefly
the dynamic aspect of reproduction.

CHAPTER III
HEREDITY

Generation is a continuation of growth—The cause of the normal
hypersensibility of the testis and ovary—Dynamic impulses
bear the character of the parts from which they proceed—
The bed-rock of the dynamic theory—The translation of
the influence of regional environment through the nervous
system to the testis and ovary— Evidence of dynamic
elements in the spermatozoa and ova—The transmission of
acquired character—The dynamic transmission of syphilis—
The influence of a previous impregnation—The determina-
tion of sex.

Nutrition is, if one may so express it, stationary Genera-
growth. ‘Generation,’ said Letourneau, ‘is so much 28%
a continuous growth that its processes are identical ae
with or analogous to those of growth.’ In dealing
with the nutritive or metabolic processes of the body
two kinds of force were defined, the electro-chemical
force, or that of atoms and of ether, and the nervous
force. In the problems connected with reproduction
these factors again recur for the simple reason so well
expressed by Letourneau, ‘ that generation is a con-
tinuous growth.’ The primary impulse in repro-
duction comes from the tissues, and is transmitted

The cause
of the
normal
hypersen-
sibility of
the testis

and ovary.

158 HEREDITY

through the nervous system, which is the great link
between the parts of the parent and those of the
child. The very act of procreation is essentially
nervous. It is characterized by a degree of nervous
excitation which is almost without a parallel, and the
consequence of which, when of too frequent occurrence,
is in the highest degree prejudicial to the general
nutrition of the body.

It will be understood that the most excitable part
of the nervous system is that which is most easily
affected by vibrations generally. When a person has a
weak spot, let it be the lungs or the stomach, or the
kidney, or the facial nerve, anything such as a chill
which disturbs the general health acts with double
force on the nerves of that particular part, whichever
it may be, and causes a greater amount of irritability
or vibratory activity than elsewhere. Now, it is very
natural to suppose that the excitability of the nerves to
the sexual organs should communicate itself in the
first place and in the highest degree to those parts of
the nervous system which are functionally most
closely related to them—that is to say, to the nerves,
to the testis, or to the ovary. Thus it happens that
these nerves and the centres in the spinal cord on
which they depend are under normal conditions also
more excitable than other portions of the nervous
system. It follows, therefore, that whenever any
action takes place in other parts of the nervous
system—or, for the matter of that, in the tissues with
which it is connected—there is a greater or less

HEREDITY 159

vibratory movement or reaction in the nerves and
nerve-cells of the aforesaid organs; indeed, it is
scarcely more, if at all, surprising that a transmission
of this kind should take place in the case of a part of
the nervous system which is normally hypersensitive
than in that of a part which under pathological
conditions is frequently so. It is true that reaction
in the latter instance may sometimes be caused
indirectly through the altered condition of the blood
or in other ways, but this does not apply to all cases.
Thus when, as sometimes happens, a sensitive person
will cough or sneeze at the mere opening of a door,
we must attribute this to an excess of sensibility or
readiness to vibrate in certain portions of the nervous
system—in other words, the effect produced is primarily
dynamic. So perfect a conducting medium is the
nervous system that no form of transmission need be
a cause for wonder. The well-known operation of
Paul Bert on a rat’s tail and many other instances
prove the truth of this statement, and the conditions
being—as it is clear they are—permanently favour-
able, we may be sure that a channel for the passage
of what one may term hereditary impulses always
exists.

Dynamic effects proceeding from various parts of
the body would each bear a certain character
depending on the conditions which gave rise to them,
since force is always influenced to some extent by the
matter through which it passes or from which it
issues. The study of sound furnishes us with some

160 HEREDITY

one striking examples of such reactions. When the bow
bear the of a violin is drawn across the strings force passes
of the parts along them and away, carrying with it and com-
they pro. Mmunicating to the air, and through the latter to the
=e human ear and brain, the peculiar characteristics
resulting from a certain length, thickness, and degree
of tension. The string has acted as a mould for the
force. It has imbued it with its properties. If we
wish to penetrate still deeper into the problem we
may say that it is the force inherent in matter which
has reacted on the force passing through it. So it is
with the essential parts of all musical instruments,
and so also with the tissues of the body. All forms of
force are alike in this respect: they are all influenced
by the matter from which they proceed.
The a When one reflects that the character of all
dynamic substances, whatsoever be their origin, is determined
sai by the degrees of force by which their atoms and
molecules are held together, when one considers that
change of shape in any given mass can result only
through the addition or subtraction of force, the real
meaning and importance of this factor in physiological
processes will become apparent. In order that the
various parts of any organism should be reproduced
it is absolutely essential that they should be repre-
sented in some way in the spermatozoa or ova, as the
case may be. If there be no link between them no
reproduction can take place. Does this imply that
each kind of tissue is represented by a cell, or a part
of a cell, or a certain number of molecules in the

HEREDITY 161

spermatozoon or the ovum? Not atall. That which
is essential is that the spermatozoon or the ovum
should constitute foci of influences or impulses
proceeding from every tissue, and representing each
not only specifically, but in extent, in shape, in actual
condition. It is clear that the shape and conformation
of, let us say, the nose, the brow, the chin, could not
by any possibility be transmitted from parent to child
unless the force by which this is brought about
corresponded to each of these parts, not specifically,
but absolutely. In other words, the various cells of
which the nose, the brow, and the chin, are composed
are represented in the spermatozoon not as single
types of cells, but as collections of individual cells.
Only by force—and in this case by physiological force
corresponding exactly to the mould in which it is
generated—is it possible to produce or reproduce
shape. This is the bed-rock on which the dynamic
theory of heredity rests.
Attention has been drawn to the fact that the The trans-

motor nerves are essentially nerves of chemical action, the in .

fluence of
and in this respect all other nerves may be said to regional

resemble them to a greater or less extent by reason of (et°™
the metabolism which constitutes an essential part of tg!
their environment, both when functionally active and fystem,to
when at rest. But whether the control which the 2”4 ovary.
nervous system exercises on metabolism is chiefly
through the sensory nerves and cells, or chiefly
through the motor nerves and cells, or through a
combination of the two, it is difficult to say, though

11

162 HEREDITY

combined action seems to be the most probable
hypothesis. One thing, however, appears certain: the
nerve-cells, whether they be motor or sensory, and
whether their fibres be afferent or efferent, vibrate
strictly in measure and in accordance with the
chemical processes which are taking place. Further,
the effects of this vibration are felt in other parts of
the nervous system besides the specially active cells,
so that any other cells ready or inclined to vibrate
would quickly do so in response to, and in accordance
with, the stimulus. The argument, therefore, runs
thus: Chemical force is liberated in the processes of
physiological action and tissue change. Force will
inevitably travel most readily along the lines of least
resistance or of greatest conductivity, that is to say,
along the nervous channels, and as it does so it will
stimulate most easily the most excitable centres,
which are the normally hypersensitive centres con-
trolling the generative organs. These in turn will
vibrate in measure and in agreement with the nature
of the stimuli reaching them from every part of the
body and due to metabolic action. In such a state-
ment, it will be understood, allowance must be made
for counteracting influences, which, however, though
they modify, do not essentially alter the normal
conditions.

The part which the cerebellum plays in the repro-
ductive processes is the same as in other forms of
physiological action, namely that of a reinforcing
organ.

HEREDITY 163

The chief anatomical facts respecting the nervous
supply of the reproductive organs is given below.*

* After section of the spinal cord above the lumbar enlarge-
ment in dogs, all the processes of generation, including parturi-
tion, may still take place, which shows clearly that the nervous
mechanism of these acts was still complete after the operation.
It is, indeed, in the lumbar portion of the spinal cord that the
special centres of the various acts included in generation have
been located (Ferrier, loc. cit., p. 18). Stimulation of the second
and third lumbar nerves in the monkey causes a powerful contrac-
tion of the vas deferens (Foster, loc. ctit.,p. 1510). In the dog and
cat fibres passing from the anterior roots of the first and second,
and sometimes from the third sacral nerves control the vaso-
motor mechanism of the sexual organs. In the monkey they
proceed from the seventh lumbar and first sacral nerves (<bid.,
p- 1509). The nerves of the penis are derived from the pudic
nerve, which arises in turn from the third and fourth, and some-
times from the second, sacral nerves, and from the hypogastric
plexus. The cremaster muscle is supplied by the ilio-inguinal, a
branch of the lumbar plexus. The nerves to the testis proceed
from the sympathetic system, and are derived from the spermatic
plexus, ‘a set of delicate nervous filaments which descend upon
the spermatic artery from the aortic plexus.’ This latter is
joined by branches of the lumbar ganglia of the cord. Some
fibres reach the testis from the hypogastric plexus, which also
supplies the vesicule seminales. The nerves of the vagina come
from the hypogastric plexus of the sympathetic, the fourth sacral,
and the pudic nerves; those of the uterus from the hypogastric
and spermatic plexuses, and from the third and fourth sacral
nerves. The nerves of the ovaries are derived from the ovarian
plexus and from the uterine nerves.

Thus the nervous supply to the reproductive organs is a very
complicated nature, and the only links of importance which can
be established at present between them and the centre in the
lumbar portion of the cord on which they depend appear to
consist of those fibres of the sympathetic system connecting, on
the one hand, the spermatic and ovarian plexuses, and on the
other hand the hypogastric plexus with the aortic plexus. It

11—2

Evidence
of dynamic
elements
in the
sperma-
tozoa and
ova.

164 HEREDITY

The dynamical nature of the reproductive process
is further illustrated by the vibratile character of the
spermatozoa. Their movements, which are both
varied and rapid, are described as those of torsion,
reptation, fluttering and spiral turnings. A single
spermatozoon will move at about the rate of 2 to 3
millimetres a minute, the rate of progression varying
according to the medium in which it happens to be.
The vibratile activity is most evident in the middle
and tail portions, and some observers assert that it is
originated in those parts; but it seems more natural
to suppose that the movements are due to molecular
vibrations in the head portion—vibrations which are
the direct result of the nervous nutritive impulses
which have led to the production and the discharge
of the spermatozoon. One thing is undeniable:
spermatozoa are not merely collections of inert
matter. They are the embodiment of forces of the
most varied nature, the dynamic specialization of
every cell in the body of the parents taken together ;
and this, it is scarcely necessary to say, is in a certain
sense the highest form of specialization it is possible
for any tissue to assume.

The spermatozoa of all the vertebrate animals show
the same vibratile activity. In crustaceans there is
an apparent lack of mobility, which, however, is said

seems probable that the plexuses mentioned—the spermatic,
ovarian, and hypogastric, control the whole of the vascular
mechanism of these parts; nor is it unlikely that they govern
secretion respectively in the testis or ovary.

HEREDITY 165

to disappear when the spermatozoa enter the mucus
of the uterus. When we descend lower in the scale
of creation, in both sexuate and asexuate forms of
reproduction the dynamic element is always present.
We see it in the simple fission of such organisms as
the hydra and vorticella. We trace it again in the
segmentation of the ovulum of the aphides, in the
swimming zoospores of alge, in the antherozoids, in
the divisions of the cell fecundated by the favilla
of the pollen.* Look where we will there is ample
evidence that force plays a great and preponderating
part in reproduction.
There is a rather prevalent belief that acquired The trans-

on a mission of
characteristics cannot be transmitted from parent to acquired

offspring. Ifa man, it is said, lose a finger, or ee as
hand, or an arm, his children will not on that account
show any such deficiency. Doubtless in such a case a
child might inherit its fingers, or hands, or arms,
from its mother and not from its father, or partly
from the one and partly from the other, the positive
influence of the former naturally outweighing the
negative influence of the latter. But even in the most
improbable event of both parents having lost the same
finger or hand, there is, according to the dynamic
theory of heredity, a possibility of their issue being
quite normal in this respect. Though the parts
might be wanting it does not necessarily follow that
the nerve centres on which they once depended have
undergone degeneration. A sensation of pain is often

* Letourneau, loc cit., pp. 316-318.

166 HEREDITY

referred to limbs or portions of limbs which have been
entirely removed by the hand of the surgeon. The
nerve centres, therefore, which correspond to the
severed parts still vibrate in the old manner, and if
this is so in regard to pain, it may be assumed that a
somewhat similar state of things would obtain in
respect to the transmission of hereditary impulses.
Positive as well as negative influences deserve some
consideration. The former may be either good or
bad: they may exceed the normal degree of intensity,
or they may fall below it. It may possibly be that
when the influences proceeding from both parents are
opposed they act as mutual correctives, but, so far as
we know, there is no evidence on this point. It may
be also that a perfectly normal influence on the part
of one parent is sufficient to counterbalance abnormal
influences on the part of the other; this, however,
would seem to be more probable were the latter
deficient in intensity. But there are many abnor-
malities in the mode of functioning of the nervous
system which become, as it were, grafted on to it, and
are very frequently reproduced by hereditary trans-
mission. Let us suppose, for instance, that a couple
happens to be living in a very relaxing locality, and
that as a consequence the walls of their arteries
become somewhat flaccid, the circulation slow, and the
nerve-power generally diminished. Children born
from them under such conditions would probably
show some signs of languor and lack of vitality. On
the other hand, let us suppose that, as a result of long

HEREDITY 167

exposure, a man and his wife both contract marked
chronic bronchial irritability. In such a case the
chance of their children being similarly affected would
be very great. If we admit, as we certainly must, the
transmission from parent to child of peculiarities of
form and structure, we cannot by any method of
reasoning limit such transmission to external appear-
ances only. All that applies in this respect to each
part as a whole must inevitably apply to its minute
conformation and general condition also, to the
individual cells as well as to the collection.

When the abnormal state of any tissue assumes a The |
chronic character, so that it reacts upon the nervous yas
system, and causes it to function in an irregular Sate
manner, it is very likely to be transmitted. The
transmission may not be in the same degree, and
there is always the possibility of a child inheriting the
character of this or that part or organ from one
parent only, but there can be no doubt as to the
transmissibility in many cases of acquired character-
istics. Weaknesses which have become grafted, so to
speak, on to the nervous system, even though not
causing suffering at the time of generation or
affecting the parent to any appreciable extent, may
nevertheless be transmitted to the offspring. This is
notably the case in syphilis, the whole character and
peculiarities of which are easily explained if we look
on it as modifying the nutritive action of the nervous
system in a katabolic sense, and as being frequently
transmitted as a nervous affection of that nature to

The in-
fluence of
a previous
impregna-
tion.

168 HEREDITY

the child. Under these conditions the immunity of
the mother of a child affected by congenital syphilis
and the transmission of the disease from a father who
to all appearance is free from the virus* are not only
explicable but natural events. Hereditary effects of
the kind just described may be compared to those
which are due to the influence of a previous impreg-
nation, for in both cases it is a question of the
recurrence of a past state or of a past mode of
vibration of the nervous system. In this respect the
following examples taken from a work by Miles are of
very great interestt :

‘In 1815 a chestnut mare, seven-eighths Arabian,
belonging to the Earl of Morton, was covered by a
quagga (a species of zebra); the hybrid produce
resembled the sire in colour and in many peculiarities
of form.

‘In 1817, 1818, 1821 the same mare was covered
by a very fine Arabian horse, and produced suc-
cessively three foals, and, although she had not seen
the quagga since 1816, they all bore his curious and
unequivocal markings.’ t

‘It is stated, on the authority of Mr. William
Goodwin, veterinary surgeon to Her Majesty, that
“several of the mares in that establishment” (royal
stud at Hampton Court) ‘‘ had foals in one year which
were by Actaeon, but which presented exactly the

* Osler, ‘The Principles and Practice of Medicine,’ p. 238.
+ Manby Miles, ‘Stock Breeding,’ p. 255.
{ ‘ Philosophical Transactions,’ 1821, p. 20.

HEREDITY 169

marks of the horse Colonel—a white hind fetlock, for
instance, and a white mark or stripe on the face; and
Actaeon was perfectly free from white. The mares
had all bred from Colonel the previous year.’ ”’*

‘A colt, the property of the Harl of Suffield, got by
Laurel, so resembled another horse (Camel) that it was
whispered—nay, even asserted at Newmarket—that
it must have been got by Camel. It was ascertained,
however, that the only relation which the colt bore
to Camel was that the latter had served his mother
the previous season.’ +

‘Mr. George T. Allman, of Tennessee, gives the
following case that came under his own observation :
‘*T bred a bay mare, black points to Watson, a son of
Lexington, who is a golden chestnut, large star, both
hind and near front ankles white. After dropping the
foal to Watson, I bred the same mare to my saddle-
stallion, Prince Pulaski, a very dark chestnut, no
white save a very small star; this produce was a
facsimile of Watson in every particular.” ’}

‘Alexander Morrison, Esq., of Bognie, had a fine
Clydesdale mare which, in 1848, was served by a
Spanish ass, and produced a mule. She afterwards
had a colt by a horse, which bore a very marked
likeness to a mule; seen at a distance everyone set it

* Farmers’ Magazine, vol. xxxv., p. 180.

+ Journal of the Highland Agricultural Society, 1857-1859,
‘p. 26.

{ ‘Rural Sun,’ as quoted in National Live Stock Journal,
June, 1877, p. 245.

170 HEREDITY

down at once as a mule. The ears are 94 inches
long, the girth not quite 6 feet, and stands above
16 hands high. The hoofs are so long and narrow
that there is a difficulty in shoeing them, and
the tail is thin and scanty. He is a beast of
indomitable energy and durability, and is highly
prized by his owner.’*

‘A similar case is recorded by Dr. Burgess, of
Dedham, Massachusetts, who says: “From a mare
which had once been served by a jack I have seen a
colt so long-eared, sharp-backed, and rat-tailed that I
stopped a second time to see if he were not a mule.” ’t

‘A pure Aberdeenshire heifer was served with a
pure Teeswater bull, by which she had a first cross-
calf. The following season the same cow was served
with a pure Aberdeenshire bull; the produce was a
cross-calf, which, when two years old, had very long
horns, the parents being both polled.’

‘Mr. Darwin cites the following case from the
Philosophical Transactions, 1821: “Mr. Giles put a
sow of Lord Western’s black and white Essex breed
to a wild boar of a deep chestnut colour, and the pigs
produced partook in appearance of both boar and sow,
but in some the chestnut colour of the boar strongly
prevailed. After the boar had long been dead the
sow was put to a boar of her own black-and-white
breed—a kind which is well known to breed very true,
and never to show any chestnut colour—yet from this

* Goodale, ‘ Principles of Breeding,’ p. 48.
+ Country Gentleman, 1870, p. 426.

HEREDITY 171

union the sow produced some young pigs which were
plainly marked with the same chestnut tint as in the
first litter.” ’*

‘ Professor Agassiz states that he had ‘‘ experimented
with a Newfoundland bitch by coupling her with a
water-dog, and the progeny were partly water-dog,
partly Newfoundland, and the remainder a mixture of
both. Future connections of the same bitch with a
greyhound produced a similar litter, with hardly a
trace of the greyhound.” ’t+

‘A white woman, who has had children by a negro,
may subsequently bear children to a white man, these
children presenting some of the unmistakable pecu-
liarities of the negro race.’ t

These are only a very few of the cases given in the
work already cited, which, indeed, are so well
authenticated, so numerous, and drawn from such
independent sources, that it is quite impossible to
disregard them. Some writers, and amongst them
Dr. Carpenter, have attributed the influence of a
previous impregnation partly to the mental impression
and partly to modifications in the nature of the
blood. There is, however, no evidence whatever in
favour of the latter suggestion, whilst it is very

* © Animals and Plants under Domestication,’ vol. i., p. 485.

+ Agricultural Report of Massachusetts, 1863, p. 57.

t ‘Physiology of Man,’ by Flint, vol. v., p. 347; see also
‘Human Physiology,’ by Carpenter, p. 970; British and
Foreign Medico-Chirurgical Review, July, 1863, p. 183;

Darwin’s Animals and Plants under Domestication,’ vol. ii.,
p. 485, note.

172 HEREDITY

improbable that the mental impression alone would
suffice in all cases to account for the results actually
obtained. Others, like Professor James Law, have
suggested that the impregnated ovum impresses its
own character on the mass of the decidua, and
through this on the maternal placenta, and that this
in turn impresses its character on the decidua and
embryo of the next succeeding generation. The
objection to this, a partial one, is that the decidua
itself is renewable. We must therefore go further
than the last observer, and search for some other sort
of tissue in which the dynamic impulses embodied in
the spermatozoa and in the foetus can be stored up in
the system until they are again rendered active.
Can this tissue be any other than the nervous
system? Do we not know, as well as we know
anything in physiology, that the nervous system is a
great storehouse of impressions or impulses? Does
not the womb and all its contents constitute a most
notable portion of the environment of the nervous
system, a portion the more remarkable because of the
intensified activity which is common to both during
the period of gestation? Does not the nature of the
metabolism, going on in any part of the body,
influence the nervous system often as a whole? If
in this case there is no direct nervous connection
between the foetus and the nervous system of the
mother, are we to deny that impulses or dynamic
impressions may reach the latter through the medium
of the ether, which permeates the womb as it does

HEREDITY 173

every other part of the organism? Lastly, is not
this recurrence of the former dynamic state really
analogous to memory, and therefore entirely in
accordance with the habitual mode of functioning of
the nervous system? Darwin, as Miles remarks, ©
seemed to have taken the view that the male element
in reproduction may act directly on the mother form.
‘The male element,’ he says, ‘not only affects, in
accordance with its proper function, the germ, but the
surrounding tissues of the mother plant.’* And
again: ‘The analogy from the direct action of
foreign pollen on the ovarium and seed-coats of the
mother plant strongly supports the belief that the
male element acts directly on the reproductive organs
of the female, wonderful as is this action, and not
through the intervention of the crossed embryo.’ t
If we regard reproduction as a whole primarily and

chiefly as a dynamic phenomenon, we shall be the less
inclined to underrate the influence to which Darwin
draws attention. At the same time, however, we
must not forget that the spermatozoon itself is
essentially a vibratile body, nor overlook the fact that
reproduction may sometimes take place without actual
connection of the reproductive organs. One thing is
certain: the substance of the spermatozoon or ovum
is secondary to the force which animates them.
There is probably no difference of a chemical order
between the spermatozoon and ovum which unite to

* » Animals and Plants under Domestication,’ vol. i., p. 483.
+ Ibid., p. 486.

The deter-
mination
of sex.

174 HEREDITY

form one child and those which unite to form another,
but there are very important dynamic differences, and
it is only when the subject is approached from this
point of view that the various problems connected
with it can be treated with any hope of success.

Hereditary transmission, as applied to this or that
part, probably depends on the conductivity of the
parental nervous system and on the force of the
nutritive or metabolic impulses, and in this way one
must suppose that the sex of the offspring is
determined. There are, however, many secondary
factors in prepotency which are both variable and
difficult to ascertain. Under these circumstances it is
manifestly absurd to pretend, as some do, that a child
always inherits certain traits or characteristics from
its mother and others from its father. The utmost
that can be said is that women are more sensitive,
as a rule, than men. Greater sensibility may be
regarded as equivalent to greater conductivity, but
not to greater transmitting power. As already said,
there are other factors to consider, and any generaliza-
tion beyond this, from whatever quarter it may come,
should be received like an old woman’s tale.

The moral aspect of heredity may be expressed in a
very few words. When any form of nervous vibration
attains a high degree of intensity there is consider-
able likelihood of its bemg transmitted from parent to
child. When thus transmitted, unless counteracted,
it will often manifest itself in a still more pronounced
manner; so that acts which in one generation may

HEREDITY 175

be regarded as mere peccadilloes or errors of judg-
ment may yet lead, under slightly unfavourable
conditions, to the direst results in succeeding ones.
To attempt to lay down any rules by which the degree
of culpability attaching to any individual can be deter-
mined is entirely vain. The utmost we can say in a
general way is that our deeds, be they white or be
they black, are written in the vibrations of our
nerve-cells and in those of our descendants.

THE END

London: Bailliére, Tindall and Cox, 8, Henrietta Street, Covent Garden.