the long barrows in Germany, he shows that the index of German skulls
has risen from 77 to no less than 83 during the last thousand years or
so; and he further shows, by reasoning similar to that which I have
just given, that this rise in index can not be due to any admixture of
race. Now, to what is this rise in head index due? Dr. Ammon, who is a
professed disciple of Weismann, does not go into the question of
causation, but the simplest and most obvious explanation is that
cranial capacity has followed brain development, and that, roughly
speaking, brachycephalism implies intellectual development. A few
instances may be given, confirming this impression of the superior
intellectual capacity of the broad-headed. Prof. Karl Pearson, in his
Chances of Death (vol. i, page 205), has given the following sexual
ratios of the superiority of English, German, and French men over the
opposite sex:
------------------+----------+---------+---------
| English. | German. | French.
------------------+----------+---------+---------
| | |
Brain weight | 1.120 | 1.117 | 1.125
Skull capacity | 1.179 | 1.126 | 1.164
Stature | 1.081 | 1.078 | 1.069
------------------+----------+---------+---------
In other words, men's skulls contain about eight per cent more and
their brains weigh four per cent more than women's, even allowing for
the difference in height. So, too, there is a uniform increase of
cubic capacity from the skulls of the Australians (75 cubic
centimetres) up to the Teutons (93.5 cubic centimetres).[14] The same
authority gives the average weight of brain in a number of
brachycephalic individuals as 1,314 grammes, as against 1,287 grammes
for dolichocephalic cases.[15] Professor Pearson points out that the
higher the caste in India the broader the skull, the Brahmans being
highest, with an index of 78.86, according to the measurements of
Risley. The same writer gives a long list (page 290) of the indexes of
skulls of some thirty-seven races, ranging from Australians at the
bottom of the list, with 70.34, and headed by mediæval Jews (only
twelve skulls), with an index of 84.74. Every indication seems to
point out that in races where progress depends upon brain rather than
muscle the brain-box broadens out as a natural consequence. Little
investigation has as yet been made as to the influence of brain
development on the form of the skull, but what little has been done
all points in the same direction. Dr. Giulio Chiarugi[16] has made
some careful measurements of twenty-one brains, and has shown that in
every instance there is much greater complexity of the cerebral
convolutions in the brachycephalic as compared with the
dolichocephalic skulls, in which the brains were contained. From the
nature of the sutures of the skull it is tolerably obvious that if
brain capacity produces an enlargement of brain, the consequent
internal pressure on the skull will be lateral and tend to produce
brachycephalism. The application of all this to the case of Jews seems
obvious. If they had been forced by persecution to become mainly
blacksmiths, one would not have been surprised to find their biceps
larger than those of other folk; and similarly, as they have been
forced to live by the exercise of their brains, one should not be
surprised to find the cubic capacity of their skulls larger than that
of their neighbors. When it is remembered that they are, owing to
their persecutions, the shortest of all European folk, their relative
superiority in brain comes out even more strikingly.
[Footnote 14: Topinard, Éléments d'Anthropologie, 1885, p. 612.]
[Footnote 15: Ibid., p. 568.]
[Footnote 16: La Forma del Cervello umano e le variazioni
correlative del Cranio, Siena, 1886.]
The conclusion I have thus drawn from anthropological data receives
remarkable confirmation from the results of an inquiry I made on the
Comparative Distribution of Jewish Ability, and contributed to the
Anthropological Institute in 1886. Applying the methods of Galton, I
compared the celebrities produced by the Jewish race during the last
hundred years with those of Englishmen and Scotchmen, and came to the
conclusion that the race, as a whole, took rank between Scotchmen and
Englishmen in intellectual capacity, while if the comparison had been
confined to western Jews, who alone have had an opportunity of
displaying their talents, they would have come out superior to both.
From the anthropological side we should expect that the
brachycephalism of Jews would show itself in superior mental capacity,
and this is confirmed by the number of distinguished persons of Jewish
blood recorded in the European dictionaries of biography.
The anthropological and sociological importance of this result, if
confirmed by further inquiry, seems to me of very great significance
for the science of anthropology, and for this reason I have insisted
so much upon it. Skull capacity and cephalic index are not so much
indications of race as of intellect. If it is found that, as a rule,
each race, and even each people, tends to have a uniform cephalic
index, that would merely imply that the sociological conditions of the
said race or people were tolerably uniform as regards intellectual
development. Australians, who have had no opportunity of pitting their
wits against any other competing race, and have depended for their
existence on the fleetness of their legs and the capacity of their
stomachs to carry food from one orgy to another, have used their
brains less than all other human races, and have the narrowest skulls
of all. Teutons, who have had the largest sphere for intellectual
rivalry with their neighbors, have the broadest skulls of all except
the Jews, who have, so to speak, lived by their wits the last two
thousand years. The evidence produced by Professor Ripley of
long-headed Jews among the lower developed communities only shows that
where the brain is not much exercised the skull is not broadened.
So far, then, from history and anthropology giving contrary verdicts
with regard to the racial purity of the Jews, the above considerations
would seem to show that they rather confirm one another's
interpretation of the facts. If brain capacity and skull index follow
the intellectual struggle for existence, we should not be surprised to
find the Jews mostly broad-headed. If there had been much
intermixture with races who had less cause to exercise their brains in
the struggle for existence, we might expect a greater admixture of
dolichocephalism among them. To my mind a much stronger case could
have been made out for the admixture of the Jews by the large number
of blondes among them, ranging to about twenty per cent, but, as a
rule, in Europe blond types are dolichocephalic, and the evidence of
admixture that could be drawn from the admixture of blue eyes or brown
hair among the Jews is counterbalanced by that very evidence of their
uniform round-headedness, upon which Professor Ripley lays so much
stress. In the memoir I have frequently quoted I have given reasons
for believing that there was a blond as well as a brunette type among
the ancient Jews, and till evidence is shown to the contrary the
presence of the fair Jew is only an indication of descent from the
earlier blond strain of the race.
Professor Ripley has scarcely taken into account the more positive
arguments I have adduced in my memoir for the comparative purity of
Jewish descent. I have pointed out a definite class of Jews--the
Cohens, or priestly descendants of Aaron--who can not, according to
Jewish law, marry proselytes. These still constitute, I have
calculated, some five per cent of Jews even at the present day. He
appears to think that this is merely a matter of name, and asks how I
would explain the existence of quasi-Jewish names, such as Davis,
Harris, Phillips, and Hart, among Christian populations of the
Anglo-Saxon world. As a matter of fact, it can be proved that, on the
contrary, these names among the Jews have been adopted for "mimicry"
reasons from the corresponding Christian names which are mostly
derived from the Bible. But, at the best, Professor Ripley's argument
would merely prove a certain amount of Jewish blood among the
Christian populations of Europe and America, which nobody would deny.
That Jews, under the pressure of persecution or for other reasons,
have abjured their faith, married Christian wives, and become merged
in the surrounding populations, is undoubtedly a fact, but does not in
any way affect the relative purity of the "remnant" which has remained
true to its faith. It certainly does not affect the very important
fact that the ancestry of at least five per cent of Jews at the
present day can not have married proselytes, owing to the rigid
requirements of Jewish law.
So far as I understand the latter part of Professor Ripley's second
article, he appears to contend that the remarkable similarity of the
Jewish physiognomy all over the world has no force in proving their
racial unity. This is, of course, from the popular point of view, the
strongest argument which Professor Ripley has to meet. Speaking
generally, one can always tell a Jew or Jewess by the Jewish features
and expression. So marked is this that Andrée mentions an instance
where the negroes of the Gold Coast even distinguish between other
whites and Jews by its means, saying not "Here are three whites
coming," but "Here are two whites and a Jew." So marked a community of
expression and appearance would be, to an ordinary mind, an absolute
proof of unity of race, but Professor Ripley prefers to judge by the
skull beneath, rather than by the expression and features on the
surface. He hints at some obscure embryological process by which
Jewish mothers can stamp on their offspring the Ghetto expression,
whatever be the racial formation of skull. According to him, it would
appear that noses are more plastic in this regard than skulls. I do
not quite see how this would work out in detail. Are we to suppose
that a pair of snub-nosed converts to Judaism would produce offspring
with the characteristic Jewish nose because the lady convert had her
imagination influenced by the hook-noses surrounding her? Are we to
suppose that round heads can only beget round heads, but that snub
noses can produce the hooked variety as a mere result of imagination?
Mere expression one could understand could be produced by sociological
causes, and it is certainly my impression that Jews who mix more with
their fellow-citizens lose a good deal of the characteristic Jewish
expression, but that Jewish features should be influenced in this way
few people would be prepared to allow. Jewish "nostrility," as I have
termed it, and the "Jew's eye," can not be affected by change of
environment. They can be affected, I grant, by admixture with races
snub-nosed or dull-eyed, but as they have persisted throughout the
ages they are themselves a striking proof of the absence of such
admixture.
Altogether I remain unconvinced by Professor Ripley's arguments as to
any large admixture of alien elements among contemporary Jews as
unvouched for by history, and not necessarily postulated by
anthropology. The broad skulls of the Jews, if they differ from those
of earlier date (of which Professor Ripley has produced no evidence
whatever), are due to the development of Jewish capacity, owing to
their consistent attention to education and to the conditions under
which they have pursued the struggle for existence. The persistence of
Jewish features throughout the ages and the existence of an
influential minority who are not allowed by Jewish law to marry
outside their race is further proof of the position for which I have
throughout contended. If there has been a tolerably large admixture of
Jewish and alien blood throughout the Christian centuries it has been
by conversions to Christianity or Islam, not by adoption of Judaism,
and it is confirmed by history that the offspring have wandered away
from the Jewish race and have not affected the more conservative
remnant.
The significance of this result for the science of anthropology can
not be overrated. The great question of the science is that expressed
by Dr. Galton as "the struggle between Nature and nurture"--the
difference that social influences can produce on men of the same race.
Jews afford the science almost the sole instance in which this problem
can be studied in its least complex form. My own investigations have
shown that social environment has a direct influence on such
anthropometrical data as height and breathing capacity. The Jews of
the West End of London, though of the same race as those of the East
End, are superior in height and other external qualities, and this
superiority can thus be shown to be due entirely to nurture.
Similarly, if the argument I have previously adduced is correct, the
brachycephalism of the Jew is a proof that intellectual development
produces broad heads, and that, roughly speaking, the cephalic index
is a key to intellectual capacity. I should rather reverse Professor
Ripley's main contentions: breadth of skull is not a criterion of
race, but of intellectual development; whereas features, which are not
directly influenced by social or intellectual characteristics, are the
true index to racial purity.
SOME PRACTICAL PHASES OF MENTAL FATIGUE.
BY PROF. M. V. O'SHEA.
I.
Modern studies in neurology have contributed much to our knowledge of
the function of the nervous system as a whole and of its several
parts, and also of the relation of psychical activity to cerebral
conditions and processes. The architecture of the neural mechanism
delineated by these investigations is not only interesting in itself
on account of the marvelous unity of things apparently diverse, but it
is at the same time suggestive respecting its office as the physical
instrument through which mind must express itself in this world.
Psychologists now quite generally conceive of a living being, human or
otherwise, as a reacting organism, receiving impressions from its
environment and responding to them in some characteristic manner. To
be fitted for this office an individual must be provided with
appliances alike for the reception of stimulations and for their
transformation into incitements to muscular activity. In the human
species Nature has ordained that action need not follow immediately
and inevitably upon any sense stimulus; fortunately, it may be
deferred, so that when it does finally occur it will be the resultant
of any given present impression modified by others previously received
and treasured up in memory, as we say. To accomplish this really great
feat, Nature had to devise an elaborate contrivance, interposed
between incoming messages and outgoing impulses, to act as a moderator
or transformer of a very extraordinary and intricate character--the
central nervous system, comprising the brain and spinal cord. That it
may be able to meet the requirements of its office, this system must
be equipped with two principal kinds of apparatus--cells, which will
serve as storehouses of energy to be employed in keeping the machinery
running, and association fibers or pathways, which will put any one
cell into communication with others in the cerebral community.
The item which will engage our attention principally here relates to
the primary function of the nerve cell--to store up vital forces in
the form of highly unstable chemical compounds,[17] which may upon
slight disturbance be broken down, the static energy represented in
their union thus becoming dynamic. Those who have given special
attention to the matter seem to agree that all activity, physical as
well as mental, involves the expenditure of a portion of this
energy.[18] It may perhaps be mentioned in passing that when this
conception was first being presented some persons hastily constructed
the theory that what people had been calling mind was nothing more nor
less than a certain mode of manifestation of this mysterious but yet
physical force. While abundant evidence, gained from various sciences
by recent research, leads one to the conviction that in some unknown
manner psychical and neural processes are closely co-ordinated, yet
not a single investigator of standing claims that they are identical.
There is doubtless among some in our day too great a tendency,
unconscious though it may be for the most part, to declare that a
description of the physical correlates or antecedents of mental
phenomena fully accounts for the latter in respect alike of their
nature and their modes of manifestation; but those who find themselves
coming to such conclusions might be both interested in and benefited
by examining the opinions of great naturalists and psychologists who
have reflected long and profoundly upon the world-old problem of the
connections between body and mind--such men as Lotze,[19] Darwin,[20]
Romanes,[21] Wallace,[22] Fiske,[23] Drummond,[24] Wundt,[25] and
many others of equal scientific attainments.
[Footnote 17: For chemical formulæ of some of the compounds, see
Ladd, Outlines of Physiological Psychology, p. 13.]
[Footnote 18: For the opinions of investigators, as Mosso,
Lombard, Maggiora, Kraeplin, and others, see Pedagogical
Seminary, vol. ii, No. 1, pp. 13-17; Scripture, The New
Psychology, chapter xvi; and Educational Review, vol. xv, pp. 246
_et seq._]
[Footnote 19: Microcosmus, p. 162.]
[Footnote 20: Descent of Man, p. 66.]
[Footnote 21: Mental Evolution in Man, pp. 218 _et seq._]
[Footnote 22: Darwinism, p. 469.]
[Footnote 23: Destiny of Man in the Light of his Origin.]
[Footnote 24: Ascent of Man.]
[Footnote 25: Human and Animal Psychology, pp. 5-7 and 440-445.]
The architecture and chemical constitution of the neural elements
indicate unmistakably, it seems, that they were so constructed that in
their functioning they would be amenable to the law of the
conservation of energy, and recent investigations have produced some
experimental evidence in support of this view. Hodge,[26] who
succeeded in making microscopical examinations of living nerve cells
while under stimulation, demonstrated that the cell by this treatment
was depleted of its contents, as revealed in the gradual reduction of
its size. In corroboration of these results it was found that the
cerebral cells in animals were larger in the morning than after a
day's activities, indicating that depletion must have taken place
during waking life, followed by recuperation in sleep. Some
interesting data relating in a way to this matter are easily gained in
the laboratories by the use of the plethysmograph, which is designed
to record the degree of blood pressure in different parts of the body.
This instrument may be put upon the wrists and head, for instance, and
it may be observed, when a person is subjected to certain influences
whether, there is any alteration in blood supply in either region. It
may be noticed, as a matter of fact, that when one is required to
think diligently upon any problem, or being asleep is awakened or even
disturbed by a noise in his environment, the volume of blood decreases
in the wrist and increases in the head.[27] This same phenomenon is
shown by experiments with the scientific cradle.[28] The inference
from these data seems reasonable, that mental activity causes an
expenditure of nerve force, which Nature seeks to replenish by
inciting an unusual flow of nutritive-bearing fluid to the cerebral
cortex. It has been shown, in further illustration of this law, that
thought increases the temperature of the head, indicating that heat is
generated through molecular activity; and also that psychical action
increases waste products in the system, which may be derived only from
the degradation of substances in nerve cells.[29] So information
obtained from various other sources points toward the conclusion that
in all activity energy stored in nerve cells is dissipated.
[Footnote 26: For a complete statement of methods and results,
see Hodge, American Journal of Psychology, vol. ii, pp. 3 _et
seq._; and vol. iii, pp. 530 _et seq._]
[Footnote 27: See Pedagogical Seminary, vol. ii, pp. 12 _et
seq._]
[Footnote 28: Ibid., _op. cit._]
[Footnote 29: Cowles, Neurasthenia and its Mental Symptoms, pp.
17 _et seq._]
Recent experimental studies have given us reasons for believing that
nerve cells in different individuals yield up their energy in response
to stimulation with varying degrees of readiness.[30] Experience
corroborates what Professor Bryan[31] has said: that some persons
possess a leaky nervous system, wherefrom their vitalities flow away
without issue in useful results. In such individuals activity will be
likely to be in excess of that which the stimulus occasioning it
should normally produce. Every one must have seen children, and adults
as well, who when they hear a slight noise, for instance, which others
do not mind, react with great vigor by jumping or screaming; or, when
spoken to unexpectedly the face flushes, the lip quivers, and they
become physically uncontrolled in a measure. In these instances the
persons are unduly profligate in the expenditure of their means, and,
in consequence, their capital is relatively soon exhausted.[32]
[Footnote 30: Educational Review, _op. cit._]
[Footnote 31: Addresses and Proceedings of the National
Educational Association, 1897, p. 279.]
[Footnote 32: _Cf._ Warner, The Study of Children, chapters viii
and ix.]
The writer last year conducted some experiments upon school children
which yielded results that appear to confirm the view here set forth.
Scripture's steadiness gauge was used in one test. This is designed to
investigate stability of control by requiring a person to direct a
light rod under guidance of the eye upon a point several feet distant,
failure to accomplish this being announced by the ringing of an
electric bell. The subject is usually required to make the trial
fifteen times at a single test, and the number of successful attempts
is taken to be in a way, although not always reliable, an index to his
power of co-ordination. But more important than the success or failure
in accomplishing the task is the index it affords of the nervous
condition of the subject as revealed in the expressions of face and
body. Tests were made in the morning, shortly following the opening of
school, and again at half past eleven o'clock, or thereabouts, after
the pupils had been working over their lessons for about two hours.
One boy of eleven years, A. M., is a fair illustration of what might
not inappropriately be called an exhaustive type, wherein nervous
energy is readily depleted because of incessant waste. In the morning
tests he was well controlled and accurate. A record of five tests made
at half past eleven all show that after four or five attempts to place
the rod upon the point the hand became very unsteady, the lips
compressed, the region about the eyes showed unusual constraint, and
the hand not being used was tightly clinched. Ten trials were usually
sufficient to produce twitchings or _tics_ in the face and body,
although nothing of this was ever noticed at other times. This boy
invariably made hard work of the task, and all the physical
accompaniments indicated excessive motor stimulation following, of
course, upon an unduly excited condition of the cerebral cells. At the
close of the experiments he generally seemed exhausted, and upon three
occasions it was thought best not to permit him to make the entire
fifteen trials.