is induced in some persons by the mere idea of having partaken of any
unusual food, as of an animal which is not commonly eaten; although
there is nothing in such food to cause the stomach to reject it.
When vomiting results, as a reflex action, from some real cause--as
from too rich food, or tainted meat, or from an emetic--it does not
ensue immediately, but generally after a considerable interval of
time. Therefore, to account for retching or vomiting being so quickly
and easily excited by a mere idea, the suspicion arises that our
progenitors must formerly have had the power (like that possessed
by ruminants and some other animals) of voluntarily rejecting food
which disagreed with them, or which they thought would disagree with
them; and now, though this power has been lost, as far as the will is
concerned, it is called into involuntary action, through the force of a
formerly well-established habit, whenever the mind revolts at the idea
of having partaken of any kind of food, or at anything disgusting. This
suspicion receives support from the fact, of which I am assured by Mr.
Sutton, that the monkeys in the Zoölogical Gardens often vomit while in
perfect health, which looks as if the act were voluntary. We can see
that as man is able to communicate, by language to his children and
others, the knowledge of the kinds of food to be avoided, he would have
little occasion to use the faculty of voluntary rejection; so that this
power would tend to be lost through disuse.
SHRUGGING THE SHOULDERS.
[Expression of
the Emotions,
page 271.]
We may now inquire why men in all parts of the world, when they
feel--whether or not they wish to show this feeling--that they cannot
or will not do something, or will not resist something if done by
another, shrug their shoulders, at the same time often bending in their
elbows, showing the palms of their hands with extended fingers, often
throwing their heads a little on one side, raising their eyebrows,
and opening their mouths. These states of the mind are either simply
passive, or show a determination not to act. None of the above
movements are of the least service. The explanation lies, I can not
doubt, in the principle of unconscious antithesis. This principle here
seems to come into play as clearly as in the case of a dog, who, when
feeling savage, puts himself in the proper attitude for attacking and
for making himself appear terrible to his enemy; but, as soon as he
feels affectionate, throws his whole body into a directly opposite
attitude, though this is of no direct use to him.
* * * * *
Let it be observed how an indignant man who resents and will not
submit to some injury holds his head erect, squares his shoulders, and
expands his chest. He often clinches his fists, and puts one or both
arms in the proper position for attack or defense, with the muscles
of his limbs rigid. He frowns--that is, he contracts and lowers his
brows--and, being determined, closes his mouth. The actions and
attitude of a helpless man are, in every one of these respects, exactly
the reverse.
BLUSHING.
[Expression of
the Emotions,
page 310.]
Blushing is the most peculiar and the most human of all expressions.
Monkeys redden from passion, but it would require an overwhelming
amount of evidence to make us believe that any animal could blush. The
reddening of the face from a blush is due to the relaxation of the
muscular coats of the small arteries, by which the capillaries become
filled with blood; and this depends on the proper vaso-motor center
being affected. No doubt, if there be at the same time much mental
agitation, the general circulation will be affected; but it is not due
to the action of the heart that the net-work of minute vessels covering
the face becomes, under a sense of shame, gorged with blood. We can
cause laughing by tickling the skin; weeping or frowning, by a blow;
trembling, from a fear of pain, and so forth; but we can not cause a
blush, as Dr. Burgess remarks, by any physical means--that is, by any
action on the body. It is the mind which must be affected. Blushing
is not only involuntary, but the wish to restrain it, by leading to
self-attention, actually increases the tendency.
* * * * *
[Page 312.]
The tendency to blush is inherited. Dr. Burgess gives the case of a
family, consisting of a father, mother, and ten children, all of whom,
without exception, were prone to blush to a most painful degree. The
children were grown up; “and some of them were sent to travel, in
order to wear away this diseased sensibility, but nothing was of the
slightest avail.” Even peculiarities in blushing seem to be inherited.
Sir James Paget, while examining the spine of a girl, was struck at
her singular manner of blushing: a big splash of red appeared first
on one cheek, and then other splashes variously scattered over the
face and neck. He subsequently asked the mother whether her daughter
always blushed in this peculiar manner, and was answered, “Yes, she
takes after me.” Sir J. Paget then perceived that, by asking this
question, he had caused the mother to blush; and she exhibited the same
peculiarity as her daughter.
* * * * *
[Page 318.]
Mr. Washington Matthews has often seen a blush on the faces of the
young squaws belonging to various wild Indian tribes of North America.
At the opposite extremity of the continent, in Tierra del Fuego,
the natives, according to Mr. Bridges, “blush much, but chiefly in
regard to women; but they certainly blush also at their own personal
appearance.” This latter statement agrees with what I remember of the
Fuegian, Jemmy Button, who blushed when he was quizzed about the care
which he took in polishing his shoes, and in otherwise adorning himself.
* * * * *
[Page 319.]
Several trustworthy observers have assured me that they have seen
on the faces of negroes an appearance resembling a blush, under
circumstances which would have excited one in us, though their skins
were of an ebony-black tint. Some describe it as blushing brown, but
most say that the blackness becomes more intense.
* * * * *
[Page 324.]
I will give an instance of the extreme disturbance of mind to which
some sensitive men are liable. A gentleman, on whom I can rely,
assured me that he had been an eye-witness of the following scene: A
small dinner-party was given in honor of an extremely shy man, who,
when he rose to return thanks, rehearsed the speech, which he had
evidently learned by heart, in absolute silence, and did not utter a
single word; but he acted as if he were speaking with much emphasis.
His friends, perceiving how the case stood, loudly applauded the
imaginary bursts of eloquence, whenever his gestures indicated a pause,
and the man never discovered that he had remained the whole time
completely silent. On the contrary, he afterward remarked to my friend,
with much satisfaction, that he thought he had succeeded uncommonly
well.
BLUSHING NOT NECESSARILY AN EXPRESSION OF GUILT.
[Page 333.]
It is not the sense of guilt, but the thought that others think or know
us to be guilty, which crimsons the face. A man may feel thoroughly
ashamed at having told a small falsehood, without blushing; but if he
even suspects that he is detected he will instantly blush, especially
if detected by one whom he reveres.
On the other hand, a man may be convinced that God witnesses all his
actions, and he may feel deeply conscious of some fault and pray for
forgiveness; but this will not, as a lady who is a great blusher
believes, ever excite a blush. The explanation of this difference
between the knowledge by God and man of our actions lies, I presume,
in man’s disapprobation of immoral conduct being somewhat akin in
nature to his depreciation of our personal appearance, so that through
association both lead to similar results; whereas the disapprobation of
God brings up no such association.
Many a person has blushed intensely when accused of some crime, though
completely innocent of it.
* * * * *
[Page 334.]
An action may be meritorious or of an indifferent nature, but a
sensitive person, if he suspects that others take a different view of
it, will blush. For instance, a lady by herself may give money to a
beggar without a trace of a blush, but if others are present, and she
doubts whether they approve, or suspects that they think her influenced
by display, she will blush. So it will be, if she offers to relieve the
distress of a decayed gentlewoman, more particularly of one whom she
had previously known under better circumstances, as she can not then
feel sure how her conduct will be viewed. But such cases as these blend
into shyness.
* * * * *
[Page 338.]
The belief that blushing was _specially_ designed by the Creator is
opposed to the general theory of evolution, which is now so largely
accepted; but it forms no part of my duty here to argue on the general
question. Those who believe in design will find it difficult to
account for shyness being the most frequent and efficient of all the
causes of blushing, as it makes the blusher to suffer and the beholder
uncomfortable, without being of the least service to either of them.
They will also find it difficult to account for negroes and other
dark-colored races blushing, in whom a change of color in the skin is
scarcely or not at all visible.
BLUSHING ACCOUNTED FOR.
The hypothesis which appears to me the most probable, though it may at
first seem rash, is that attention closely directed to any part of the
body tends to interfere with the ordinary and tonic contraction of the
small arteries of that part. These vessels, in consequence, become at
such times more or less relaxed, and are instantly filled with arterial
blood. This tendency will have been much strengthened, if frequent
attention has been paid during many generations to the same part, owing
to nerve-force readily flowing along accustomed channels, and by the
power of inheritance. Whenever we believe that others are depreciating
or even considering our personal appearance, our attention is vividly
directed to the outer and visible parts of our bodies; and of all such
parts we are most sensitive about our faces, as no doubt has been the
case during many past generations. Therefore, assuming for the moment
that the capillary vessels can be acted on by close attention, those
of the face will have become eminently susceptible. Through the force
of association, the same effects will tend to follow whenever we think
that others are considering or censuring our actions or character.
* * * * *
[Page 340.]
It is known that the involuntary movements of the heart are affected if
close attention be paid to them. Gratiolet gives the case of a man who,
by continually watching and counting his own pulse, at last caused one
beat out of every six to intermit. On the other hand, my father told me
of a careful observer, who certainly had heart-disease and died from
it, and who positively stated that his pulse was habitually irregular
to an extreme degree; yet to his great disappointment it invariably
became regular as soon as my father entered the room.
* * * * *
[Page 342.]
When we direct our whole attention to any one sense, its acuteness is
increased; and the continued habit of close attention, as with blind
people to that of hearing, and with the blind and deaf to that of
touch, appears to improve the sense in question permanently. There is,
also, some reason to believe, judging from the capacities of different
races of man, that the effects are inherited. Turning to ordinary
sensations, it is well known that pain is increased by attending to it;
and Sir B. Brodie goes so far as to believe that pain may be felt in
any part of the body to which attention is closely drawn.
A NEW ARGUMENT FOR A SINGLE PARENT-STOCK.
[Expression of
the Emotions,
page 361.]
I have endeavored to show in considerable detail that all the chief
expressions exhibited by man are the same throughout the world. This
fact is interesting, as it affords a new argument in favor of the
several races being descended from a single parent-stock, which must
have been almost completely human in structure, and to a large extent
in mind, before the period at which the races diverged from each other.
No doubt similar structures adapted for the same purpose have often
been independently acquired through variation and natural selection
by distinct species; but this view will not explain close similarity
between distinct species in a multitude of unimportant details. Now, if
we bear in mind the numerous points of structure having no relation to
expression, in which all the races of man closely agree, and then add
to them the numerous points, some of the highest importance and many of
the most trifling value, on which the movements of expression directly
or indirectly depend, it seems to me improbable in the highest degree
that so much similarity, or rather identity of structure, could have
been acquired by independent means. Yet this must have been the case
if the races of man are descended from several aboriginally distinct
species. It is far more probable that the many points of close
similarity in the various races are due to inheritance from a single
parent-form, which had already assumed a human character.
XIV.
THE PROVISIONAL HYPOTHESIS OF PANGENESIS.
[Animals and
Plants under
Domestication,
vol. ii,
page 349.]
Every one would wish to explain to himself, even in an imperfect
manner, how it is possible for a character possessed by some remote
ancestor suddenly to reappear in the offspring; how the effects of
increased or decreased use of a limb can be transmitted to the child;
how the male sexual element can act not solely on the ovules, but
occasionally on the mother-form; how a hybrid can be produced by the
union of the cellular tissue of two plants independently of the organs
of generation; how a limb can be reproduced on the exact line of
amputation, with neither too much nor too little added; how the same
organism may be produced by such widely different processes as budding
and true seminal generation; and, lastly, how, of two allied forms,
one passes in the course of its development through the most complex
metamorphoses, and the other does not do so, though when mature both
are alike in every detail of structure. I am aware that my view is
merely a provisional hypothesis or speculation; but, until a better one
be advanced, it will serve to bring together a multitude of facts which
are at present left disconnected by any efficient cause. As Whewell,
the historian of the inductive sciences, remarks, “Hypotheses may
often be of service to science when they involve a certain portion of
incompleteness, and even of error.” Under this point of view I venture
to advance the hypothesis of pangenesis, which implies that every
separate part of the whole organization reproduces itself. So that
ovules, spermatozoa, and pollen-grains--the fertilized egg or seed, as
well as buds--include and consist of a multitude of germs thrown off
from each separate part or unit.
FUNCTIONAL INDEPENDENCE OF THE UNITS OF THE BODY.
[Page 364.]
Physiologists agree that the whole organism consists of a multitude
of elemental parts, which are to a great extent independent of one
another. Each organ, says Claude Bernard, has its proper life, its
autonomy; it can develop and reproduce itself independently of the
adjoining tissues. A great German authority, Virchow, asserts still
more emphatically that each system consists of an “enormous mass
of minute centers of action.... Every element has its own special
action, and, even though it derive its stimulus to activity from other
parts, yet alone effects the actual performance of duties.... Every
single epithelial and muscular fiber-cell leads a sort of parasitical
existence in relation to the rest of the body.... Every single
bone-corpuscle really possesses conditions of nutrition peculiar to
itself.” Each element, as Sir J. Paget remarks, lives its appointed
time and then dies, and is replaced after being cast off or absorbed.
I presume that no physiologist doubts that, for instance, each
bone-corpuscle of the finger differs from the corresponding corpuscle
in the corresponding joint of the toe; and there can hardly be a doubt
that even those on the corresponding sides of the body differ, though
almost identical in nature. This near approach to identity is curiously
shown in many diseases in which the same exact points on the right and
left sides of the body are similarly affected; thus Sir J. Paget gives
a drawing of a diseased pelvis, in which the bone has grown into a most
complicated pattern, but “there is not one spot or line on one side
which is not represented, as exactly as it would be in a mirror, on the
other.”
Many facts support this view of the independent life of each minute
element of the body. Virchow insists that a single bone-corpuscle or
a single cell in the skin may become diseased. The spur of a cock,
after being inserted into the ear of an ox, lived for eight years,
and acquired a weight of three hundred and ninety-six grammes (nearly
fourteen ounces) and the astonishing length of twenty-four centimetres,
or about nine inches; so that the head of the ox appeared to bear three
horns. The tail of a pig has been grafted into the middle of its back,
and reacquired sensibility. Dr. Ollier inserted a piece of periosteum
from the bone of a young dog under the skin of a rabbit, and true bone
was developed. A multitude of similar facts could be given.
* * * * *
[Page 368.]
What can be more wonderful than that characters, which have disappeared
during scores, or hundreds, or even thousands of generations, should
suddenly reappear perfectly developed, as in the case of pigeons and
fowls, both when purely bred and especially when crossed; or as with
the zebrine stripes on dun-colored horses, and other such cases? Many
monstrosities come under this same head, as when rudimentary organs
are redeveloped, or when an organ which we must believe was possessed
by an early progenitor of the species, but of which not even a
rudiment is left, suddenly reappears, as with the fifth stamen in some
_Scrophulariaceæ_.
* * * * *
[Page 369.]
In every living creature we may feel assured that a host of long-lost
characters lie ready to be evolved under proper conditions. How can
we make intelligible, and connect with other facts, this wonderful
and common capacity of reversion--this power of calling back to life
long-lost characters?
* * * * *
[Page 336.]
Imperfect nails sometimes appear on the stumps of the amputated
fingers of man; and it is an interesting fact that with the snake-like
saurians, which present a series with more and more imperfect limbs,
the terminations of the phalanges first disappear, “the nails becoming
transferred to their proximal remnants, or even to parts which are not
phalanges.”
* * * * *
[Page 387.]
Mr. Salter and Dr. Maxwell Masters have found pollen within the ovules
of the passion-flower and of the rose. Buds may be developed in the
most unnatural positions, as on the petal of a flower. Numerous
analogous facts could be given.
I do not know how physiologists look at such facts as the foregoing.
According to the doctrine of pangenesis, the gemmules of the transposed
organs become developed in the wrong place, from uniting with wrong
cells or aggregates of cells during their nascent state; and this would
follow from a slight modification in their elective affinities.
* * * * *
[Page 388.]
On any ordinary view it is unintelligible how changed conditions,
whether acting on the embryo, the young or the adult, can cause
inherited modifications. It is equally or even more unintelligible, on
any ordinary view, how the effects of the long-continued use or disuse
of a part, or of changed habits of body or mind, can be inherited. A
more perplexing problem can hardly be proposed; but on our view we
have only to suppose that certain cells become at last structurally
modified, and that these throw off similarly modified gemmules. This
may occur at any period of development, and the modification will
be inherited at a corresponding period; for the modified gemmules
will unite in all ordinary cases with the proper preceding cells,
and will consequently be developed at the same period at which the
modification first arose. With respect to mental habits or instincts,
we are so profoundly ignorant of the relation between the brain and
the power of thought that we do not know positively whether a fixed
habit induces any change in the nervous system, though this seems
highly probable; but, when such habit or other mental attribute, or
insanity, is inherited, we must believe that some actual modification
is transmitted; and this implies, according to our hypothesis, that
gemmules derived from modified nerve-cells are transmitted to the
offspring.
NECESSARY ASSUMPTIONS.
[Page 369.]
I have now enumerated the chief facts which every one would desire
to see connected by some intelligible bond. This can be done, if we
make the following assumptions, and much may be advanced in favor of
the chief one. The secondary assumptions can likewise be supported
by various physiological considerations. It is universally admitted
that the cells or units of the body increase by self-division or
proliferation, retaining the same nature, and that they ultimately
become converted into the various tissues and substances of the body.
But besides this means of increase I assume that the units throw off
minute granules which are dispersed throughout the whole system; that
these, when supplied with proper nutriment, multiply by self-division,
and are ultimately developed into units like those from which they
were originally derived. These granules may be called gemmules. They
are collected from all parts of the system to constitute the sexual
elements, and their development in the next generation forms a new
being; but they are likewise capable of transmission in a dormant state
to future generations and may then be developed. Their development
depends on their union with other partially developed, or nascent cells
which precede them in the regular course of growth. Why I use the term
union will be seen when we discuss the direct action of pollen on the
tissues of the mother-plant. Gemmules are supposed to be thrown off by
every unit, not only during the adult state, but during each stage of
development of every organism; but not necessarily during the continued
existence of the same unit. Lastly, I assume that the gemmules in their
dormant state have a mutual affinity for each other, leading to their
aggregation into buds or into the sexual elements. Hence, it is not the
reproductive organs or buds which generate new organisms, but the units
of which each individual is composed. These assumptions constitute the
provisional hypothesis which I have called pangenesis.
* * * * *
[Page 372.]
But I have further to assume that the gemmules in their undeveloped
state are capable of largely multiplying themselves by self-division,
like independent organisms. Delpino insists that to “admit of
multiplication by fissiparity in corpuscles, analogous to seeds
or buds ... is repugnant to all analogy.” But this seems a strange
objection, as Thuret has seen the zoöspore of an alga divide itself,
and each half germinated. Haeckel divided the segmented ovum of a
siphonophora into many pieces, and these were developed. Nor does the
extreme minuteness of the gemmules, which can hardly differ much in
nature from the lowest and simplest organisms, render it improbable
that they should grow and multiply. A great authority, Dr. Beale, says
that “minute yeast-cells are capable of throwing off buds or gemmules,
much less than the 1/100000 of an inch in diameter”; and these he thinks
are “capable of subdivision practically _ad infinitum_.”
A particle of small-pox matter, so minute as to be borne by the wind,
must multiply itself many thousandfold in a person thus inoculated;
and so with the contagious matter of scarlet fever. It has recently
been ascertained that a minute portion of the mucous discharge from an
animal affected with rinderpest, if placed in the blood of a healthy
ox, increases so fast that in a short space of time “the whole mass of
blood, weighing many pounds, is infected, and every small particle of
that blood contains enough poison to give, within less than forty-eight
hours, the disease to another animal.”
* * * * *
[Page 374.]