CONTAGIOUS AND INFECTIOUS DISEASE
Among the gains of human advance in evolution stand out prominently
complete immunity from certain diseases due to germs, and partial immunity
from others, which last immunity results in chronic types, rather than in
acute, because of increased vital resistance in man. Tuberculosis and
dourine, acute diseases in the cow and horse, have become chronic
diseases, tuberculosis (or consumption) and syphilis, in man. Such
chronicity is evidence of advance, yet it constitutes an element of
degeneracy, since the victim of the chronic disease is able to leave more
offspring than would be possible were the disorder acute. In other
respects acute and chronic contagions and infections exert the same
influence in regard to degeneracy. The germ of the disease may be
inherited, or general nutrition of the foetus may be so checked in
development that the child inherits a predisposition to disease.
Through this check to foetal development the phagocytes, or white blood
cells, become so weakened that they are unable to devour foetal structures
as useless to man as the tadpole's tail (which it devours) is useless to
the developed frog. This power being weakened, the organs which form
antitoxins (or protective tonics against disease), from lack of
development fail to perform their function. For this reason in the
degenerate many infections and contagions assume their old destructive
type.
The influence of these disorders in the parent may result in the bony
mal-development shown to occur in animals by Charrin and Gley, and in man
by Coolidge. The facial bones, jaw, and teeth are peculiarly liable to be
thus affected. Though the effect of the disease on the parent be but
temporary, the child's development may be checked as to higher tendencies.
Thus mothers have borne moral imbeciles, epileptics or lunatics, after a
pregnancy during which they were attacked by contagious disease, albeit
the children of subsequent and previous pregnancies were normal.
The children of pregnancies previous to the one complicated by the
contagious disease may be healthy, while those of subsequent pregnancies
are defective. Any contagious or infectious disease may not only interfere
temporarily with the bodily strength, but may produce complete change in
the parent's system extending even to the highest acquirement of man. In
some occur changes thus graphically described by Bulwer: "There have been
men who, after an illness in which life itself seemed suspended, have
arisen as out of a sleep with characters wholly changed. Before gentle,
good, and truthful, they now become bitter, malignant, and false. To those
whom they before loved they evince repugnance and loathing. Sometimes this
change is so marked and irrational that their kindred ascribe it to
madness. Not the madness which affects them in the ordinary business of
life, but that which turns into harshness and discord the moral harmony
which results from natures whole and complete."
The nerve centres controlling nutrition, growth, repair, secretion, and
excretion are often as deeply affected as those checks constituting
morality. At the periods of physiologic stress these effects are
especially noticeable. Moral insanity, intellectual insanity, unequal
mental balance, hysteria, precocious sexuality, unconscious mendacity,
mental parasitism (the germ of pauperism), epilepsy, neuroses, and all
types of nutritive and constitutional defects result. The nutritional
defects may appear chiefly in the walls of the blood vessels and
lymphatics. While these are most common in the chronic infections and
contagions, they often occur in acute typhoid fever, scarlatina,
diphtheria, whooping-cough, &c. Proper blood supply and utilisation of
waste is thus prevented. Organs cannot perform their function, and are
predisposed to disease from disuse and from weakness of the
disease-fighting phagocytes and antitoxins. From this results irregularity
of organ function, which is hereditarily transmissible. The weakened
vessel walls yield to strain, and thus produce local stomach, bowel,
liver, gland, and kidney disorders. This organ weakness may alone be
transmitted to the offspring. The functions of the great glands (thyroid,
thymus, suprarenals, pituitary body, bone-marrow, testicles and ovaries)
which secrete principles necessary to the equal balance of nutrition are
perverted. The liver, in the acute but more particularly the chronic
contagions, paralysed in nerve tone, fails in its function of
poison-destroyer, as for the same reason the kidneys fail in their power
of ejecting hurtful waste. Through this interaction of perverted
nutrition, imperfect poison-destruction, and deficient waste ejection
result and continue the states of nervous exhaustion after the contagions
and infections. Thus nerve exhaustion with its suspicion, its capricious
hopefulness and gaiety, is practically continuous in tuberculosis,
syphilis, and leprosy.
The acute and chronic contagions and infections so lower cell vitality
through the perverted functions described that inert connective tissue
replaces healthy working cells. This is especially the case with syphilis,
which, when driven from the system, leaves behind it a tendency to disease
based on this connective tissue increase. This tendency, latent in the
ancestor, may be so intensified in the descendant as to produce the
hereditary ataxias (loss of movement power), and like neuroses. At the
periods of stress such tendencies are peculiarly potent, and not only
check, but reverse development. The chronic contagions and infections are
most fertile sources of human degeneracy since their weakened products are
enabled to survive under modern beneficence. Of these chronic contagions
two (tuberculosis and syphilis) alone deserve attention, since the third
(leprosy) exerts but little influence. Despite its existence for more than
a century (New Brunswick and Nova Scotia on the north and Louisiana on the
south) on the borders of the United States, despite its subsequent
importation from Norway, Sweden, China, and Hawaii, its spread has been
infinitesimal, and its influence on race deterioration is still less
demonstrable.
Tuberculosis ("the white death") is from every standpoint a social danger
more serious than syphilis. The father, as in syphilis, can infect the
mother, but sterility is much less likely. As has already been shown in
the chapter on heredity, plural and quickly repeated birth are common in
tuberculous families. The tuberculous diathesis (or "habit," as Weismann
calls it) was very early observed in the United States. Nearly seventy
years ago W. P. Dewees, of Philadelphia, pointed out its frequency and its
early observation by the Greek and Roman physicians. He cites a case
illustrative of the extent and uniformity of diathesis in a very numerous
family. This predisposition arose on the side of the mother, though she
lived herself to the age of forty-three, a period much exceeding that of
any of her children, with the exception of a son, who died in his
forty-fifth year. This lady bore twenty-three children without being able
to suckle any but the two first. The males much exceed the females in
number, yet there did not appear to be any exception to their favour in
the transmission of the phthisical taint, except that they attained in
general a greater age before they died. Some died about puberty, others at
manhood or womanhood; but all, with the exception just stated, under
thirty. The disease was never very rapid; they generally complained from
one to two years before they died. The men had a healthy, even in some
instances an athletic, appearance until the disease became open and
decided. In their growth and stature they altogether resembled the father,
who was not only a remarkably stout man, but lived beyond the eightieth
year. The females, who passed puberty (two in number) were rather stout
women, while the mother was both delicate and small. This family lived in
the country, was very wealthy, and always accustomed to the various means
generally found successful either in destroying the predisposition or
lessening its influence, yet in no one instance in this family were they
successful, though the open form of the disease was retarded perhaps in
all. The females died the earliest.[168]
The blood vessel system is affected as regards development in such
families. The heart is often diminutive; the right ventricle is
exaggerated. Two great types of degenerate constitutions are produced in
children of the tuberculous. One of these may well come under De
Giovanni's category of the torpid. The victim is usually coarse-featured
and coarse-skinned, with peculiarly unstable mentality; slowness of
comprehension is combined with power of continuity of thought; at times
mental apathy alternates with quickness of perception. Decided
exaggeration of the lymphatic system (connected with utilising of material
elsewhere than at the point where it has been rendered unfit) with
deficient function occurs, resulting in fitting a soil for germs. In other
respects the torpid resembles the second type, the erethistic (nervously
fussy type) of De Giovanni. This is generally characterised by the
presence of a clear complexion, a fine skin, and features well cut and
often beautiful. The lips are red and the teeth pearly white, though
liable to early decay, and the eyes are large and full, the pupil being
widely dilated and the white of the eye beautifully clear. The eyelashes
are long, curved and silky, and the blue veins show distinctly through the
clear thin skin. The bones are light, the hands and feet well formed, the
stature often tall, and the whole figure slightly and gracefully built.
The erethists generally remain spare, and have a strong dislike to fatty
food. They are vivacious and excitable, and the intellectual faculties are
often highly developed. At an early age they show marvellous activity. The
regularity with which such precocious tubercular children die has given
rise to proverbs anent exceptionally clever children that they are "too
wise to live long." Wanting in stamina, they are incapable of prolonged
exertion either of mind or body, and break down under conditions which
would not prove injurious to the healthy. They are continually taking
"cold," and are prone throughout life to affections of an inflammatory
character. Multiple and frequent pregnancies occur. The children,
deficient in vitality, are carried off in numbers during infancy by
convulsions, brain fever, water on the brain, exhaustion, diarrhoea,
teething, and other ailments, or they succumb at the second detention or
at puberty. A small proportion reach maturity. Few live beyond thirty-five
or forty years of age. However brilliant intellectually, they are equally
emotional, impressionable, and impulsive. There is a marked absence of
mental stability. They are suspiciously capricious. The great secreting
and eliminating glands undergo with peculiar frequency the perversions
already described.
Neuroses and psychoses are peculiarly frequent in childhood and youth. The
degenerative power of tuberculosis is not always due to the influence of
the germ, or even of the toxin produced by it, but to the state of nerve
weakness resultant on the disorder. The victim of tuberculosis (especially
if affecting the lung) is a suspicious, yet hopeful, nervous invalid,
whose functions are irregularly performed and who is therefore likely to
leave scions with greater defect, especially as the maternal factor,
either through infection or worry, can hardly escape being weakened.
Tuberculosis attacks the bones of the offspring, especially the spine and
hip-joint, but the victim of these last frequently regain health after
apparent recovery from the local disease through surgical procedures. If
the victim of the hip-joint disorder be of the erethist type marriage is
not unlikely. Despite the deformity produced by spine disorder, popular
superstition as to the "good luck" of a hunchback leads to marriage among
the working class. Monetary and social considerations effect the same
result among the wealthy classes. Here deformity does not prevent
marriage, but predisposes to sterility through birth difficulty.
The influence of syphilis is, in a general sense, the same as that of
tuberculosis, except that by reversing the principle of individuation it
leads to greater sterility. Furthermore it exhibits greater tendencies to
revert towards health, and yields (even in the inherited form) more to
medicinal treatment. The inherited form at times presents itself in two
types closely simulating those due to tuberculosis. Like the bacillus of
tuberculosis, the syphilitic germ attacks every structure and organ of the
body. Its reversal of the principle of individuation, causing excessive
cell formation, produces more decidedly demonstrable effects. As syphilis
is more apt to attack the central nervous system than tuberculosis, it
would seem that it is a greater race-deteriorating factor. The excessive
tendency to cell formation, however, produces impotence in man, sterility
and abortion in woman. There are very good reasons for believing that the
race is becoming immune to syphilis, and that this disease will disappear.
Its greatest race-deteriorating effect is in preparing the soil for
tuberculosis and other infections and contagions.
The influence of contagions and infections on degeneracy is therefore by
no means slight. Each disease can produce grave constitutional defects in
the ancestor likely to be intensified in the offspring. The greatest
social dangers result from tuberculosis; the next from syphilis. Typhoid
fever, scarlatina, small-pox, measles, diphtheria, whooping-cough, and all
other contagions, however, may produce these constitutional defects,
either through the mother during pregnancy or through their secondary
effects on the ancestor's constitution. If the subject be attacked before
the close of the periods of dental stress an arrest of development of the
bones of the face may result with irregularities in the shape and position
of the teeth. These, then, are stigmata of degeneracy, especially due, in
the individual presenting them, to the contagions and infections rather
than to inheritance alone.