CAUSES AND SIGNS OF PHYSICAL DETERIORATION.
_Modern Care for the Individual._
In the last chapter we saw that while selection is an evident
and powerful factor in the production of racial change, there is
but slight and in many cases questionable evidence that acquired
characters are ever transmitted. During their lifetime a man or
woman may be subject to the most varied conditions, and yet the
quality of his or her offspring will not be affected by these
conditions except in cases where impoverishment or poisoning of
the blood has ensued, thereby enfeebling his or her reproductive
cells. These facts have not been gained by a study of the lower
animals alone, for most researchers have kept man in view, while
others, like Malthus and Galton, have confined their observations
almost exclusively to the human kind. In this chapter we shall see
how these generalisations are borne out by the study of disease,
and we shall see what effect the modern methods for the treatment
of the sickly and feeble are having upon the race. We moderns as
individuals have many advantages over those who have gone before
us; we owe to the untiring energy of our ancestors the facilities
for travel, the pleasures of accumulated music and literature,
etc., but among these hundreds of advantages we possess none are
more marked than those we owe to the scientific followers of the
profession of medicine, the application of whose learning gives
in our day to the less robust a possibility of life and happiness
they never had before.
_Preventive Medicine._
The words “mederi,” to heal, “medicus,” the healer, and “medicina,”
the remedy, indicate pretty clearly the almost superstitious feeling
current in early times regarding the attributes of the medical man;
but physicians have in more recent years begun to doubt in some
measure of their power to cure disease when once established. With
increased knowledge, and with growth of professional acumen, the
limits of this power are more clearly seen, and the solution of a
metallic salt, or decoction of a herb is now withheld when at one
time it would have been administered with the fullest confidence.
With this healthy scepticism as to their power to cure has come
very certain and exact knowledge of how to prevent, and preventive
medicine has recently exercised an influence upon disease and upon
mortality which is unique in the history of humanity. But while
the benefit of our changed and more healthy surroundings are to
the advantage of us all individually, we shall have to consider
whether as a people we shall in the long run be the better for this
change, or, on the other hand, whether in obtaining this individual
advantage we are not imperilling the vigour of the race.
_Micro-organisms of Diseases and their Extermination._
Nowhere has preventive medicine achieved greater triumph than in the
extermination of certain micro-organisms which gain access to the
body and cause the febrile class of diseases, such as small-pox,
measles, typhoid fever, and very many others. At present none of
these micro-organisms can be said to be extinct, but they have in
some cases been banished to distant parts of the globe, and in other
cases the conditions suitable to their existence, and the means of
their propagation are so well understood that their banishment is
being systematically and successfully carried out, so much so that
a disease such as small-pox, which at one time headed the list of
fatal diseases, does not come in the category of anxieties of the
mother of to-day; and pyæmia and puerperal fever, which twenty
years ago were at times dreaded scourgers in most hospitals, now
occur only from culpable and punishable neglect.
_The Reproductive Cells are as a Rule unaffected by them._
A short study of these diseases should well repay us, showing as
it will do that in by far the greater number of cases these severe
constitutional derangements produce no effect upon the reproductive
cells; that they are in fact incapable of producing a change that
will be hereditarily transmitted. We shall learn, moreover, the
part that they have played, and can play, in producing racial
change by selection. The micro-organisms of disease are of many
varieties, and each variety is capable of setting up its own peculiar
disturbance. The disturbance set up by one kind we call small-pox,
that arising from another kind, cholera, and so on. Now, the very
curious point comes out that in most of these diseases, although
the composition of the blood is profoundly altered, and many of the
tissues undergo marked change, this change, fortunately for us, is
quite of a temporary character, and when the attack is over there
is only one test which will enable us to say that the body is not
just in the same condition as it was before. This test is that it
cannot be infected again for a long time, if at all, by the same
micro-organism.
This induced immunity from further attacks has received in the
hands of Metschnikoff a curious and very interesting explanation.
He has shown that an army of small cells, called phagocytes, which
wander through the blood and tissues, are able to attack the
microbes of disease, and that after a struggle they are able in
many cases to kill these voracious invaders. In so doing, however,
the weaker phagocytes succumb to the struggle, while those which
are left alive within the body of the convalescent patient possess
the power of resisting and destroying the particular microbe which
had undertaken the invasion. These resisting phagocytes, selected
from the rest, together with their descendants, who share their
resisting qualities, are able to prevent fresh inroads of the same
enemy. We need not, therefore, assume that this acquired immunity,
the sole relic of the attack, indicates any change in the ordinary
muscle or brain cells of the body, or that the reproductive cells
are in any way altered, for the immunity is due only to a change
in the phagocytic army.
The germ cells in almost every case get off scot-free, and there is
nothing in the organisation of a child to indicate whether or not
his father or mother suffered from measles, or scarlet fever. It
might at first sight be urged, in opposition to this fact, that,
although we cannot recognise the child of a man who suffered from
measles or scarlet fever by any visible sign, yet the child is in
some way different, inasmuch as he is to some extent immune to those
diseases. In favour of this belief, the many instances in which a
fever has been brought to a country never before accessible to the
germ (for instance, the introduction of measles and small-pox to
newly discovered America, where fearful ravages were caused thereby),
may be brought up as evidence to prove that those habitually living
among the germs must have become immune and have transmitted this
immunity to their progeny. Again, the black population of Sierra
Leone have only a mortality of 24 per cent. from malaria, while the
mortality of the white settlers is 47 per cent.;[12] and, in this
case, it may be urged that the black race has become by transmission
of immunity partially immune. But these cases which appear to be
examples of transmitted immunity may receive another, and a much
more simple, explanation. No two children of the same parents are
alike in colour of hair, shape of limb, temperament, etc., and
they also differ widely in their capacity to receive and combat
infection. An epidemic of fever, therefore, will always select to
kill those organically most liable to fall a prey to it, while the
remnant, having by nature greater power of resistance, not only
survive, but may also be calculated upon to produce progeny, on
the whole, as resistant as they are themselves.
_Man has been selected by the Action of the Microbes of Fever._
Races, therefore, subject to epidemics of a particular fever,
suffer selections in the hands of the microbe of that particular
fever, and those living are survivals cast in the most resisting
mould. It may not be flattering to our national vanity to look upon
Englishmen as the product of the selection of the micro-organisms
of measles, scarlet fever, small-pox, etc., but the reasonableness
of the conclusion seems to be forced upon us when we consider his
immunity from these diseases as compared with that of natives of the
interior of Africa, or of the wilds of America, whose races have
never been so selected, and who, when attacked for the first time
by these diseases, are ravaged almost to extermination. We find,
then, that an ordinary attack of measles, scarlet fever, whooping
cough, erysipelas, typhoid, or typhus fever, when it has passed away,
leaves the tissues of the body in as sound and healthy a condition
as before; and, indeed, were it not for this fact, the human race
could hardly have existed at all, continually exposed as it has
been, for countless ages, to the aggressions of these microbes. By
exterminating these diseases, we shall, no doubt, preserve countless
lives to the community, who will in their turn become race producers,
but, inasmuch as the individuals thus preserved will in many cases
belong to the feebler and less resisting of the community, the race
will not become more robust. In fact, it is probable that, as a
race, we shall thereby suffer, for the banishment of the disease
will enable the feebler members of the community to live, and in
larger proportion contribute to the progeny of the future. That
this is actually the case will shortly be pointed out.
_Leprosy an Exterminator of the Unhealthy._
But there are other microbes which, in addition to the production
of blood changes, have a profound and lasting effect upon many
of the tissues of the body. Such are the microbes of leprosy and
syphilis.
The terrible ravages that the microbe of leprosy is capable of
effecting are appreciated only by those who in Norway or elsewhere
have visited those death-houses now fortunately to be found in but
one or two parts of Europe. Yet, even in this case, strange to say,
the germ cells do not seem to be reached by this loathsome disease,
and it is not transmitted from parent to child.[13] A disease of
mediæval, not of modern, Europe, we need not discuss its action on
racial change more than to say that, hideous as are its aspects, it
must be looked upon as a friend to humanity; for, while the microbe
of typhoid fever will attack a man who is healthy and living in
healthy surroundings--excepting for the microbe that lurks in his
well--the microbe of leprosy feeds upon those who are debilitated
by conditions under which healthy and strong racial development is
impossible. It is a depopulator of starved, ill-nourished districts,
and the race recruits to its advantage from those more favourably
placed.
In the case of syphilis, serious and often permanent tissue change
is produced as a result of the action of the microbe, and in this
disease, to an absolute certainty, an effect may be produced upon
the offspring. Many suppose that this is due to the transmission
of the specific microbe itself from the body of one or both of the
parents to the developing egg. That such a thing is not impossible
is shown in the case of silk-worm disease, in which the spores are
to be found within the egg of the silk-worm moth. These spores
subsequently develop and attack the tissues of the grub of the next
generation. In syphilis the same kind of thing no doubt occurs;
for a syphilitic child may subsequently infect the mother or nurse
during the period of suckling. But there are other cases in this
disease which appear hardly to be explained so easily, and we have
to assume that the germinal cells are themselves changed in some
way during their sojourn in the parental body, for after a certain
time the disease is no longer capable of transmission by the
parent, and the children born after this period, though themselves
diseased, are incapable of infecting those who tend them. We have
every reason to believe, therefore, that there are no specific germs
or microbes left in the body of the parent, and that we have to do
solely with the more or less permanent change in the reproductive
cells, produced by the microbes during their residence in the body
of the parent. The children born during this period are frequently
ill-nourished, possess recognisable indications of disease, and
are subject to nervous and other affections.
We have here, therefore, for the first time, distinct evidence that
an obviously acquired constitutional disease is transmitted, and
that that transmission is in some cases due to a direct effect of
the action of the microbe upon the germinal cells. The microbe of
syphilis, unlike the microbe of leprosy, but like that of measles,
feeds on healthy blood and tissue. It attacks the strong as well
as the weak, and, if the weak more readily succumb, yet the strong
and vigorous are more apt to acquire it. It is not, therefore,
selective, like leprosy, and this fact, added to that of its capacity
of transmission, ranks it as a disease distinctly inimical to race
progress.
_Germs of Phthisis and Scrofula, our Racial Friends._
During recent years it has been discovered that the symptoms of
phthisis and scrofula are due to a microbe, the tubercle bacillus.
It appears, however, that this bacillus cannot gain access to, or
multiply in, the tissues of a healthy and vigorous man or woman;
most of us probably have often carried this micro-organism within
the mouth or stomach, and though our gastric juice has not been able
to destroy it, as is the case with so many of our invisible foes, it
has been unable to pass into our blood or lacteals. Dr. Woodhead puts
this fact strongly.[14] He says: “A perfectly healthy individual,
placed under favourable conditions as regards food, fresh air, and
exercise, is never attacked successfully by tubercle bacilli, the
active, vigorous tissue cells being perfectly able to destroy any
bacilli that make their way into the lungs, the pharynx, or the
intestine.”
It appears, too, that a certain type of individual is readily
attacked by this microbe, while the normal individual, debilitated
though he may be by unfavourable external conditions, falls far less
readily a victim. As Prof. Sir Lauder Brunton[15] remarks: “We
are constantly meeting with persons belonging to very consumptive
families who escape the disease by living under conditions where
the bacillus tuberculosus is likely to be absent. On the other
hand, persons such as nurses are in all probability frequently
inhaling the microbe, and yet are not attacked by the disease.
In the first case immunity is probably due to the absence of the
seed, notwithstanding the favourable condition of the soil; in the
second it is due to the barrenness of the soil, notwithstanding
the presence of the seed.”
Inasmuch as phthisis is markedly hereditary, we may look upon the
_type_, not the disease, as being transmitted. A phthisical type of
person is one who comes of a family liable to fall a prey to this
microbe, and he is recognisable by many distinctive characteristics
of hair and complexion, and by qualities of temperament, feature,
and figure.
Sufferers from phthisis are prone to other diseases, such as pulmonary
and bronchial attacks, so that over and above the vulnerability to
this one form of microbe they are to be looked upon as unsuited not
only for the battle of life, but especially for parentage and for
the multiplication of the conditions from which they themselves
suffer.
The phthisical are attractive in personal appearance on account of
their rich skin and hair colouring and their frequent brightness
and vivacity, and their obvious delicacy also elicits a feeling
of pity and wish to protect them. In consequence of this they
easily marry, and they are as a rule very fertile. Galton[16] says:
“There is fair doubt whether a group of young persons destined
to die of consumption contribute considerably less to the future
population than an equally large group who are destined to die of
other diseases.” Now this phthisical type is very common with us
indeed, and it appears to be an innate variation to which our race
is liable. It is evident, therefore, that those people with the
tuberculous variation who, even under the present circumstances,
manage to contribute their quota to the population, would, were the
bacillus tuberculosus altogether exterminated, contribute more than
their share, and the type would become more common. And let it be
remembered that this type, apart from the action of the bacillus,
is a delicate and fragile one and liable to other affections, and
the effect of giving the type any advantage in the struggle for
life would surely imperil the well-being of the future of the race.
When, some years ago, it was thought that a cure for phthisis had at
last been obtained, great tribute was naturally and rightly paid to
its discoverer; but had this cure proved as efficient as the more
sanguine were led to expect, it would be terrible to contemplate
the eventual suffering that would have resulted from the constantly
increasing numbers of the phthisical type that would have been
born with each generation.
_If we stamp out Infectious Diseases we perpetuate Poor Types._
It is a hard saying, but none the less a true one, that the bacillus
tuberculosus is a friend of the race, for it attacks no healthy man
or woman, but only the feeble. It is like the bacillus of leprosy
in this respect, but in this respect only, for leprosy attacks
anyone living under certain unhygienic conditions. Remove these
conditions--as we have done long ago--and the bacillus of leprosy
disappears; its duties are over, like those of the extinct plants
and fishes in the rocks.
The tubercle bacillus on the other hand attacks a type to be found
not only in the poor, ill-fed, and ill-conditioned, but also those
who live well. It is a disease of all classes, and those who
live in well-ventilated rooms, and who conform to every sanitary
regulation, may still belong to the type who fall a prey to it. It
is certain, therefore, that, improve the external conditions of
life how you will, this type will remain. It is also as certain
that in giving the type a better chance than it has already, by
preventing infection or by delaying the disease, the type will be
more and more prevalent as each generation comes to life.
It comes out pretty clearly from our short study of the infective
diseases that some of the microbes that cause these, such as the
bacillus of tubercle, only feed on unhealthy human tissue, while
the greater number of them kill, if anything, the weak rather than
the strong. They are, therefore, on the whole, and as a natural
consequence, our race friends rather than our foes, and if we attempt
seriously to do away with their selective influence--_viz._, the
elimination of the weak and the preservation of the strong--we must
supply this selective influence by one equally potent, or the race
will tend to deteriorate. What can be done in the future, and what
it is expedient for us to do at the present time, will be more fully
discussed in a subsequent chapter; but I may state at once that
_pari passu_ with our endeavour to prevent these diseases must be
our efforts to enlist the co-operation of the human charity that
would avert suffering in such selection as shall necessitate the
birth of future generations from the healthiest and best of those
amongst us. As selection is the race-changer, we must replace the
selection of the microbe by the selection of human forethought.
A number of diseases, which are due probably to innate family
predispositions, are known to us. Of these diabetes, hæmophilia,
and some others are of comparative rarity, and may be left on one
side in this necessarily contracted sketch. Others, such as cancer
and constitutional weakness of the respiratory and other organs, as
well as insanity, are frequent enough to merit our close attention.
Of cancer we at present know too little, and I propose to leave
it on one side. Of inherited weakness of special systems we have
many examples, such as a delicate respiratory or digestive mucous
membrane, inherited variations in the mechanism of assimilation,
and also gout and obesity--in fact, innate delicacy of all kinds,
which renders their possessor less able to cope with his natural
surroundings, let these be what they may.
There is hardly a family that can boast of the complete want of
hereditary weakness, and among the children of particular families,
where these weaknesses exist, some show the taint more than others.
In times of hardship, cold, exposure, coarse food, etc., these
weaker ones perish, and the race is consequently propagated from
the stronger ones. Within certain limits cold, exposure and coarse
food are compatible with great physical excellence, for the cold
and exposure, hurtful to the sickly, braces and hardens the more
robust, and coarse but nutritive food supplies him with energy and
strengthens the powers of digestion. The finest races have been bred
by hardship. It is proverbial to speak of “the hardy mountaineer,”
and one cannot look at a lowland Scot without feeling that his stock
had, in days gone by and for many centuries, run the gauntlet of
oatmeal porridge and cold east wind.
But we are rapidly diminishing those selective agencies which in the
past have developed race vigour. As we shall presently see, skill
in nurturing the sickly has, in modern times, wonderfully reduced
the mortality amongst infants; improvements in methods of nursing,
the replacement of cotton by flannel and wool, and the use of many
foods, some of them artificially digested, gives a sickly infant a
chance of living, and it survives its first most dangerous years.
Then its chances are again improved, for the infective diseases
are being held in check, and it has comparatively little to fear
from them. Thus it survives and lives to adult age, when, like the
hothouse plant, it is still protected from hardships to which the
race had formerly been freely exposed. It lives to lower the average
physique of the mothers or fathers who produce the next generation
of children.
This increased preservation of the sickly has had the effect of
increasing the life period of an average child, and this increase in
the life probability is often and very rightly cited as an indication
of the improved sanitary conditions of the people. Improved sanitary
surroundings, as we have seen, are taken advantage of chiefly by
the sickly, and thus with our increased probability of life we
have diminished the average robustness of constitution, or innate
healthiness of the race, for a larger proportion of sickly ones are
living amongst us. In our day a greater number of parents suffer
from phthisical, scrofulous and other taints than in days gone by,
and these and other taints are passed on to their children.
So far we have seen what of necessity follows from our biological
premises, but it is also possible, I think, to show by statistics
that already very observable deterioration has taken place.
_Births, Deaths, and Marriages._
If we examine one of the reports of the Registrar General for
births, deaths and marriages, we shall gain pretty full information
concerning the deaths from disease, accident, old age, etc., that
have occurred during the last thirty or forty years.
_Increase of Constitutional Weakness._
In Report 54, Table 17, the annual death-rates from various causes
per million of population are given, and arranged in groups of
five years from 1858 to 1890. We have there a history of thirty
years, and even in that time a notable change in this history is
to be observed. I have arranged the greater number of facts given
in Table 17 in the following table, so as best to bring out those
points which we are discussing. In the first group of disease are
those due to micro-organisms, and a diminution of these diseases
to a marked extent is to be observed of late years. Phthisis and
scrofula placed by themselves in this group share in this decrease.
In the second group are diseases that are due in great measure to
carelessness, want of management, neglect and ignorance, such as
convulsions, diseases of dentition, parturition and registered
accidents. These, too, as one would expect, diminish yearly in a
country where surrounding comforts and a sense of responsibility
are on the increase. When we turn to the third group, that of
constitutional disease, where the hereditary tendency comes in, we
find an increase in almost all the hereditary diseases. A tendency
to an increase of neurotic affections is shown by an increase in
the deaths from nervous diseases, suicide and intemperance. A large
increase in the diseases of the respiratory system is due in part to
the increasing number of tuberculous patients who, kept from inroads
of microbes, nevertheless readily fall a prey to other affections:
there is, too, an increase in diseases of the circulatory system,
in cancer, diabetes and other constitutional diseases.
Annual death-rates in England from various causes, per million
persons living, in groups of years 1858–1890--
KEY
A: Phthisis and scrofula
B: Other diseases of micro-organisms
C: Diseases of dentition, parturition, convulsions, accident and
negligence
D: Some constitutional diseases
-------------------------------------------------------------------------
CAUSE
OF DEATH. 1858–60. 1861–65. 1866–70. 1871–75. 1876–80. 1881–85. 1886–90.
-------------------------------------------------------------------------
GROUP I.
A 3304·0 3311·0 3300·2 2940·6 2816·8 2540·8 2322·2
B[17] 4403·9 4498·6 4677·2 4055·8 3233·6 2708·8 2417·0
GROUP II.
C 2257·0 2262·0 2191·0 2077·2 1860·4 1678·6 1538·0
GROUP III.
D[18] 6056·3 6311·4 6594·6 7199 7536·4 7531·2 7929·4
-------------------------------------------------------------------------
[17] These include small-pox, measles, scarlet fever, simple and
ill defined fever, whooping cough, diphtheria, miasmatic diseases,
cholera, diarrhœa, dysentery, erysipelas, puerperal fever and thrush.
[18] Diseases of the nervous, circulatory and respiratory systems,
cancer, diabetes and other constitutional diseases.
This table demonstrates, therefore, in a most marked manner, the
action of modern civilisation and of preventive medicine, which, by
removing the microbe and diminishing the dangers of child-rearing,
has diminished the rate of mortality to a very notable extent in
the early years of life. The increase in the number of deaths from
constitutional diseases, occurring as they do in middle or advanced
age, are probably due to the survival of an increased number of
individuals into the period of maturity. From this table it is
difficult to say whether or no these individuals are below the mean
average type. We have to die at one period of life or at another,
and if men and women are preserved from the dangers of childhood
and youth, there will be more to fall victims to the lung and chest
complaints of more advanced life.
But it is possible by other sets of figures, obtainable from the
Registrar General’s reports, to arrive at some sort of decision as
to the healthiness of the middle-aged and elderly people living
to-day, and to compare these results with similar ones drawn from
the statistics of twenty or thirty years ago.
_Death-rate for Advanced Years on the Increase._
In table 13 (Report of the Registrar General for 1891) the death-rates
per 1,000 are given for different age periods, and these results
date from 1841 to 1890, and are arranged in groups of ten years.
The table was prepared in the following way. At each period given,
say from 1841–50, the number of persons living at a certain age was
calculated from the census returns. The numbers dying at that age
being known, these are given in the table per 1,000 persons of that
age. In order to reduce the number of figures, I have shown the
death-rates of two groups only, the first group of persons (males)
younger, and the second group of persons older than 35 years.
DEATH-RATE OF MALES PER 1000 LIVING.
-------------------------------------
GROUP I. GROUP II.
0–35 years. 35 and upwards.
-------------------------------------
1841–50 112·0 591·0
1851–60 111·2 581·9
1861–70 110·8 595·1
1871–80 101·0 616·7
1881–90 87·8 589·3
-------------------------------------
Group I. shows the very steady diminution in the death-rate of the
earlier years of life, and similar results are also brought out by
a corresponding table showing the death-rates among females.
Group II. showing the death-rates of individuals above 35 years of
age, at first sight seems to give no very satisfactory predications
of either increase or decrease of mortality, indeed the last period
indicates a very decided fall in the mortality. We have, however,
to remember that climatic influences are variable, and that certain
groups of years are especially healthy and others inimical to
well-being. That the last period is a very healthy one is indicated
by the excessive fall seen in Group I., and by a corresponding fall
in the number of deaths of females. These climatic variations may
be assumed to influence the numbers of Group II. more than those of
Group I.; indeed, on reference to the details given in the full
report, I see that the fall in that period is in large measure due
to the decreased mortality of those over 75, a time of life very
susceptible to climatic influences.
On the whole, Group II. indicates that the death-rate above 35 is
increasing, for if we add together any two consecutive periods, say
1841–50 and 1851–60, we shall find that the mortality of the last
twenty years is greater than that of the first. By taking in this
way longer periods of time, we can eliminate factors other than
the time factor, and we can, at any rate, feel strongly suspicious
that the mortality of middle and advanced life is on the increase.
The same results can, perhaps, even more conclusively be demonstrated
by a study of tables showing the expectancy of life.
_Life Tables compared._
The late Dr. Farr constructed tables showing the expectancy of life
calculated upon the death-rates of the years 1838–54, and similar
tables have more recently been constructed by Dr. Ogle, from the
death-rates of the years 1871–80. In the case of male children
newly-born, a child born in the first period could expect to live
39·91 years if he lived to an average age; a child born in the second
period had a longer expectancy of life, namely, 41·35 years. While,
however, the expectancy at birth during childhood and youth has been
increased, the following table (extracted from their tables) will
show that the expectancy during manhood has diminished; that is to
say, men are either not so strong, or their surrounding conditions
are less favourable than they were, and they cannot expect to live
for so long a period. The details of this table are as follows:--
MEAN AFTER-EXPECTATION OF LIFE.
-----------------------------
GROUP I. GROUP II.
Ages. 1838–1854. 1871–1880.
-----------------------------
0 39·91 41·35
5 49·71 50·87
10 47·05 47·60
15 43·18 43·41
20 39·48 39·40
25 36·12 35·68
30 32·76 32·10
35 29·40 28·64
40 26·06 25·30
45 22·76 22·07
50 19·54 18·93
55 16·45 15·95
60 13·53 13·14
65 10·82 10·55
70 8·45 8·27
75 6·49 6·34
80 4·93 4·79
85 3·73 3·56
90 2·84 2·06
95 2·17 2·01
100 1·68 1·61
-----------------------------
_Physical Degeneration of the Race already indicated._
It seems improbable that the short expectancy of middle age can be
due to modern overstrain, for external conditions are on the whole
improving, and the same fact may be observed in the expectancy of
women, who certainly have not been placed under more unfavourable
external conditions. Calculations from other periods of years would
be here of great value, in order further to eliminate the effects of
climatic changes, etc., and it must be remembered that the figures
which are the basis of all statistics are only approximate to, and
never exactly represent, the true condition of things. For these
reasons, it seems important to pursue statistical investigations
still further, and to examine the returns of other nations in order
to determine whether or no their facts are similar to ours.
In the meantime, we may view, and not without inquietude, the
probability that our statistics, as far as they go, indicate that
racial deterioration has already begun as a sequence to that care
for the individual which has characterised the efforts of modern
society. The biologist, from quite another group of facts, has
independently arrived at conclusions which render this view in the
highest degree probable.
FOOTNOTES
[12] Billing’s “Text-book of the Theory and Practice of Medicine,” p. 8.
[13] Report of Leprosy Commission in India, 1890–1.
[14] “Bacteria and other Products,” p. 230.
[15] “Introduction to Modern Therapeutics” (1892), p. 15.
[16] “Natural Inheritance,” p. 182.