CLIMATE, SOIL, AND FOOD
Among the factors constituting environment few have impressed the
biologist so much as climate, soil, and food. The seeming modifications
produced by these have made a very decided impression on the sceptical
Weismann, who stated that "the possibility is not to be rejected that
influences continued for a long time, that is, for generations, such as
temperature, climate, kind of nourishment, &c., which may affect the germ
plasm, as well as any other part of the organism, may produce a change in
the constitution of the germ plasm. But such influences would not then
produce individual variations, but would necessarily modify, in the same
way, all the individuals of a species living in a certain district. It is
possible, though it cannot be proved, that many climatic varieties have
arisen in this manner. Possibly other phenomena of variation must be
referred to a variation in the structure of the germ plasm produced
directly by external influences."
Considering the changes brought about in European plants and animals in
Australia, those occurring in the East Indian mongoose in Jamaica, the
changes in European plants and animals in America, or American animals in
Europe and European animals in Asia, Weismann's position seems judicial.
The influences dependent on food, soil, and climate producing normal
modifications have been remarkably illustrated in the gilled batrachian
Axolotl. This, under the nourishment and change of surroundings of the
Jardin des Plantes, was transformed into a gill-less batrachian, which had
hitherto been regarded as belonging to a totally distinct family.
According to Darwin,[169] English dogs degenerate in India in a few
generations, losing the peculiarities of form and mental character which
distinguish their particular race, in spite of the greatest care in
selection and prevention of crossing. An instance which well deserves the
consideration of those anthropologists who attach but little importance to
the influence of the environment and to the value of speech as an aid to
the ethnologist is that of the Wurtemburgers, who settled (1816) near
Tiflis in Russia. They had originally fair or red hair, light or blue eyes
and coarse, broad features. In the first generation brown hair and black
eyes began to appear; in the second black hair and eyes became the rule,
while the face acquired an oval form. These changes were due entirely to
the surroundings, no instance of crossing with Georgian natives being on
record. At the same time, these transformed Wurtemburgers continue to
speak their German mother-tongue uninfluenced by the local dialects.[170]
The alleged transformation of the British into the Yankee is commonly
cited in illustration of the supposed effects of soil and climate. Three
decades[171] ago Vogt remarked that American Anglo-Saxons or Yankees were
instanced as illustration of change of character. Already, after the
second generation, according to Pruner-Bey, the Yankee presents features
of the Indian type. At a later period the glandular system is reduced to
the minimum of its normal development. The skin becomes like leather; the
colour of the cheeks is replaced by sallowness. The head becomes smaller
and rounder, and is covered with stiff, dark hair; the neck becomes
longer, and there is greater development of the cheek-bones and the
masseters. The temporal fossae becomes deeper, the jaw-bones more massive,
the eyes lie in deep approximated sockets. The iris is dark, the glance is
piercing and wild. The long bones, especially in the superior extremities,
are lengthened so that the gloves manufactured in England and France for
the American market are of a particular make, with very long fingers. The
female pelvis approaches that of the male. According to Quatrefages,
America has thus, from the English race, produced a new white race which
might be called the Yankee race. Vogt believes that America dries up the
skin and reduces the fat, an effect to which all the above differences
might be reduced. That the head becomes smaller he utterly denies. Exact
cranial measurements by Morton show that the skull of the Yankee is at
least as large as that of the Englishman.
Similar changes have been noted in the Anglo-Saxon Australians. The true
explanation of this is that early rigorous environment tended to cause
reversion to types not uncommon even now in Great Britain, Ireland, and
Scandinavia, resultant on the admixture of primitive types to which
reference has been made. The same error has been made about the pelvis as
about the skull. The male pelvis in the American is approximating the
female in accordance with advance, since, as Havelock Ellis has
shown,[172] not only by his skull, but by his pelvis, modern man is
following a path first marked out by woman. The skull of the modern woman
is more markedly feminine than that of the savage woman, while that of the
modern man has approximated to it. Not only is the pelvis of the modern
woman much more feminine in character than that of the primitive woman,
but the modern man's pelvis is also becoming more feminine.
The validity of Vogt's position anent the "Yankee" change of type is fully
demonstrated by the following portraits of four generations of a noted
American family with a Scandinavian patronymic, coming originally from a
district in England where the alleged "Yankee" type (even to its nasal
tone and so-called "Americanisms") occurs. The first "American" of the
family (Fig. 3) was born in Connecticut in 1761 and died in 1826. He had a
dolichocephalic head with massive jaws, prominent lips, especially the
upper. The nose is long and the eyes are set close together, the forehead
very high and straight. Quite a change is noticeable in the second
generation (Fig. 4). The face is not so long, the lateral diameter of the
head is larger, the forehead more prominent, and the eyes are a little
farther apart. The nose is about the same length and while there is a
resemblance about the mouth and chin, the distance from the front of the
chin to the tip of the nose is not quite so long. The change seems to be
due to shortening of the chin.
[Illustration: FIG. 3.--DOLICHOCEPHALIC.]
[Illustration: FIG. 4.--MESOCEPHALIC.]
[Illustration: FIG. 5.--MESOCEPHALIC.]
[Illustration: FIG. 6.--BRACHYCEPHALIC.]
The next generation (Fig. 5) shows still further changes. The forehead is
broader and less retreating than either. There is perceptibly lest
prognathism. There is less prominence in the supraorbital region.
The fourth generation exhibits (Fig. 6) a nearly brachycephalic head. The
head is nearly round, forehead full, eyes set in the head to correspond
with its width, nose broad, upper lips short, and the lower jaw is
evidently much shorter in a perpendicular line. These changes are due to a
protruding forehead, receding chin, and delicate features.
The climate of the United States exercises, according to certain
sociologists, on the first generation of European immigrants, a
deleterious influence in regard to fecundity. The decrease in the
fecundity of the American woman has been charged to various anti-social
causes (abortion and prevention of conception) and to a "nervousness"
induced by the climate. A seemingly fair test of the influence of the
climate would be a race elsewhere fecund, and whose religion encourages
fecundity, decreasing in the first generation after immigration to the
United States. Such a race is the Jewish. According to Gihon's analysis of
the United States census of 1890[173] the Jewish birth rate is
diminishing. From the mothers born in the United States the average is
3.56 children, as against 5.24 for those born in Germany, 5.36 for those
in Russia and Poland, 5.27 for those in Hungary, and 5.44 for those in
Bohemia. These figures, however, do not demonstrate the influence of
climate, but of environment. The Jew, unlike the earlier American
colonists, is not exposed to the stress of frontier life. He has a more
favourable mental and physical environment than on the continent of
Europe. This fact, therefore, does not demonstrate the effects of climate,
but is really chargeable to climate, food, soil, and other factors
constituting environment. That climate cannot be considered apart from
these factors is shown, as I pointed out several years ago, by the fact
that the United States surveyors in Minnesota reported to the national
authorities that it was impossible to live the whole year in that state
because of the extremely cold winter. Now, not only do people live and
cultivate the soil throughout the entire state, but large cities have
sprung up still farther north, and the country around has become well
populated. Hence, in dealing with influences of climate, change of food
and hygienic conditions must be taken into account. The error of the
American surveyors as to the acclimatisation of the white race in cold
climates has been emphasised as to the tropics and arctics. Here, however,
the same error has been demonstrated by very careful researches. The
experience of the Arctic regions as to necessity for change in diet and
hygiene has been fully borne out by observations on the Anglo-Saxon in the
tropics. The early experience of the English in India, upon which a fatal
prognosis as to the future of British India was based, turns out to have
been erroneous.
The influence of climate involves more than temperature. Stokvis, in a
paper read before the Tenth International Medical Congress, at Berlin, on
the comparative pathology of the human races with reference to the vital
resistance of Europeans in tropical climates,[174] finds that the
European immigrant in the tropics is assailed by two hostile forces:
tropico-thermal and tropico-infectious agencies. The expression of innate
racial peculiarities, like the variations of vegetable life and the
varieties of animal life from effects of increased temperature, are such
as occur in the inhabitants of temperate regions during the height of
summer.
Marestang and Eykman find that neither high temperature alone nor
meteorological agencies, apart from other deleterious influences, can
produce that impoverishment of blood called "tropical anaemia." Stokvis
shows that the tropical European does not prove inferior to the aboriginal
with respect to thermal agencies. He is less susceptible to chill than the
native. Mortality statistics of respiratory organ affections are greater
for the native. While the European suffers more from liver disease than
the native, the latter is less addicted to alcoholic drinks and pork. The
percentage of deaths from cases treated is, however, more than twice as
great with the native as with the European. Variations of physiologic life
under tropical thermal conditions have little to do with the race. The
vital resistance of the immigrant European (the European transformed into
a permanent high-summer man) is somewhat greater than that of the native
races.
Respecting the disease-producing effects of tropical infectious agencies,
the experience of the last ten years (1880-90) is very different from that
prior to 1860.
Average annual death-rate per thousand:--
European Native
Soldiers. Soldiers.
{ 1819-28 170.0 138.0
Dutch East India Army { 1869-78 60.4 38.7
{ 1879-88 30.6 40.7
{ 1800-28 84.6 18.03
{ 1828-56 56.7
British India Army { 1869-78 19.37
{ 1876-88 16.27 21.6
{ 1820-36 121.00 30.0
British Army, Jamaica { 1879-88 11.02 11.62
These changes are the consequence of sound sanitation. "The fairest laurel
practical hygiene may boast of to-day is, doubtless, the laurel acquired
in ameliorating the sanitary conditions of the European soldiers in
tropical climates." A century ago James Lind said, "Much more than to the
climate you are indebted to your own ignorance and negligence for the
disease from which you suffer in tropical climates."
These statistics do not entirely support the declaration of Hippocrates
that "races are the daughter of climates," but tend to show that the vital
resistance of the different races in tropical climates depends more on
external conditions than on race. Acclimatibility of strong, healthy,
adult Europeans of both sexes in tropical climates must be admitted
without any reserve, provided that they assiduously observe all hygienic
rules. Stokvis disproves the allegation that the European is not able to
produce in tropical regions more than three or four generations of true
European blood, and that from the third or fourth generation onward
sterility is the rule.
So accustomed, remarked Felken, however, is a man to his environment that
it is difficult to remove an European from his home in the temperate
region to any other, and yet for him to retain his health. Much may be
done in the tropics to render climate more salubrious and sanitary
precautions will do a great deal for the health of the community. But when
all is done permanent residence for Europeans under European conditions is
out of the question in the low-lying regions of the tropics. Comparatively
few areas exist in the tropics where any great success for European
colonisation can be prophesied from altitude alone. The influence of
altitude on the physiologic characteristics is, however, very evident. The
residents at high altitudes are strong, robust, buoyant, and of great
mental and physical endurance.
In disproof of this position of Felken, Viault, of Bordeaux, has shown
that the phenomena resultant on the acclimation of man at great altitudes
comes neither from the frequency of respiratory movements nor from greater
activity of the pulmonary circulation as has been asserted, but from
increase of red blood globules. While the effects of both excessive heat
and excessive cold may be admitted, even there other factors play a part.
Very high mean temperature with low humidity is more likely to result in
sunstroke and allied conditions than high temperature with high humidity.
Low temperature of the Arctic regions tends to produce anaemia in natives
of temperate zones. Food and depressing circumstances have, however, to be
taken into consideration.
Sunstroke produces the ordinary phenomena of nervous exhaustion, but the
patient becomes more irritable, suspicious, and extremely proud. As these
patients are not recognised for a long times as insane they often marry
and produce degenerates. Kiernan reports a case in which father and mother
(both of healthy stock) were overcome by the heat during one of the
processions of the American Centenaries. The children born before the
sunstroke were healthy, but there had been no children for five years
previously. A year subsequent to the sunstroke (which was followed by a
change in character in both parents) the woman had triplets, one of which
died soon after birth from convulsions. The second of the triplets, a
girl, became epileptic at 2, a prostitute at 16, and chronically insane at
20. The third triplet became a puberty lunatic at 16. Of three children
subsequently born, two are epileptics and one is a moral imbecile who
manifests premonitory evidences of paranoia. Sunstroke, however, underlies
many cases of alcoholism. Not a few of the instances of degeneration
charged to alcoholism are, in reality, due to the nervous condition
arising from the exhaustion produced by sunstroke. To this factor was in
no small degree due the extremely large infant mortality of the English in
India of the first half of the present century. While temperature plays a
part in producing degeneracy in the offspring through its production of
systemic disorder in the ancestor, it is usually associated with other
factors which aid or predispose to its effects. It also predisposes to the
greater action of other causes. Very frequently the sun-struck person,
rendered incapable of continued labour by irritability, becomes a tramp or
a pauper, either of which conditions tends to accelerate the degenerative
process and furthermore to increase the possible chances of passing down
the effect through heredity by the ease with which illicit relationships
are contracted. The least intelligent of the prostitute class, or rather,
of that class of nymphomaniacs who have not fully entered upon a
prostitute career, are driven into the workhouse or almshouse, where they
often remain for years, or depart at intervals, leaving their offspring to
be reared at public expense. The number of such children born yearly in
almshouses is at least ten thousand in the United States.[175] An enormous
proportion of these die in infancy but sufficient survive to form a potent
source of degenerates.
The influence of overheating further predisposes to the attack of microbes
even in the temperate climates, and to constitutional defects resultant on
these.
A factor of degeneracy as related to soil on which much stress has been
laid, is that of goitre. This has been carefully studied by Munson[176]
among the Indians on the reservation in the United States. The number was
77,173, of whom 2.36 per cent. had goitre. As regards geographic
distribution the disease is more prevalent in the southern part of
Montana. Goitre was reported as practically unknown among the white
settlers living about the reservations where goitre was prevalent among
the Indians. Fully 80 per cent. of the cases occur in Indian women, the
disease being not only much less frequent, but also less decided and less
extensive in the male. The average age of onset of the disease was from 12
to 14 years. There are many instances illustrating the apparent heredity
of goitre. Several consecutive generations show its development. Only one
case is reported in which goitre was associated with cretinism. Goitre
among Indians cannot be traced to high altitudes, climate or water
containing excess of calcium magnesium salts. The disease is apparently
due to insanitary surroundings, depressing constitutional conditions,
improper and excessively nitrogenous diet. This condition of things among
the Indians bears an important relation to the facts pointed out by C. K.
Clarke,[177] of Kingston, Ontario, who found in the Canadian asylums a
large number of goitrous patients and one goitrous attendant. The goitrous
patients, who were of long residence, had come from all parts of the
dominion. The size of the goitre was in proportion to the length of the
residence. It is possible that local influence may have much to do with
the disease, though it is evident that the insane are much more liable to
it than normal persons. W. B. Fletcher, of Indianapolis, has observed
similar frequency as to goitre among the insane there, especially among
the foreigners and their immediate descendants. Cretinism, according to
Morel, was degeneracy due to a special action which a toxic principle
exercises on a cerebro-spinal system, whether by the air that is breathed
or by the substances ingested in the economy, and which, above all,
appears to have some relation to a soil where predominates the magnesian
limestone. That the last factor has some influence is shown by the fact
that goitrous enlargements are encountered in medical practice in Chicago
much more frequently than among the corresponding classes in the East. The
water in Chicago contains magnesium-lime salts, whether it be derived from
the lake or from the artesian well. The fact, however, that the Indians
and the insane exhibit a tendency to goitre indicates that behind the
influence of the soil or of diet lies a neuropathic constitution, whether
this be inherited or acquired. Cretinism is much more frequent in the
United States than was apparent ere the discovery of the value of the
thyroid glands in treatment. Under the stimulus of investigation for cases
in which to try this treatment, medical literature from all parts of the
United States has been filled with reports of authenticated cases. Among
these are scions of families which have been American for more than three
generations and which may, therefore, be considered as products of an
American environment. The same condition of things has occurred in both
Great Britain and on the European continent in districts which, prior to
1890, were supposed to be free from cretinism. This illustrates the
results of stimulus given investigation in biology rather than increase of
the disorder.
The influence of spoiled maize in producing the mixed skin, nervous and
mental disorder known as pellagra in the Italians, would seem, from the
results of the researches of Billod,[178] to be chiefly due to the
conjoined effects of unhygienic surroundings, the offspring of climate and
soil. The fungus on maize (ustilago), like the fungus on rye (ergot),
produces rather long-lasting neurosis of an epileptic character,
susceptible to transmission to the offspring of women poisoned by these
fungi. The Italian disease, pellagra, manifests the features one would
expect from an improper food taken under unhygienic conditions. While this
is undoubtedly exaggerated by the habits of the peasantry in Italy, still
in a lesser degree like effects of food are observable in other races.
The influence of the potato diet in degenerating the Irish Celt in
comparison with the Scottish Celt under the same conditions, is difficult
at present to determine for lack of data. Certainly the descendants of
this class of Irish Celts rapidly regain a handsome, healthy status under
mixed American diet, even though the hygienic surroundings in the great
cities be not the best. He who has to treat a class of neurasthenics in
whom starch digestion is impaired finds that a diet of potatoes
(undoubtedly through the auto-intoxication it produces) will increase
certain nervous symptoms, and hence the tendency to transmission to the
next generation.
In the families of the pioneers in the United States, as well as the
families of farmers in secluded valleys in Norway, Switzerland, and
elsewhere, the influence of monotony of diet, aggravated by monotony of
surroundings, has undoubtedly produced a large amount of degeneracy. Ray
Brigham of New York, Awl of Ohio, and Patterson of Illinois have shown
that there is an unusual frequency of insanity in farmers' wives which is
undoubtedly traceable to these conditions. Kiernan, of Chicago, has
reported a case fairly typical of those earlier described by the American
alienists just cited. The first generation was a woman of New England
stock, of tireless energy, to whom work was a pleasure and rest an
abhorrence, and who lived on a farm miles from the town. She did all her
own work and brought up a large family, chiefly on maize, potatoes, and
bread, pork being the meat diet. At 50 this woman removed with her
husband, who had grown wealthy, to a small country town. Here she
conducted the entire work of the household without a servant. At 52 she
broke down with neurasthenia, which rapidly passed into periodical gloomy
spells, in one of which she committed suicide. Her youngest daughter, who
had an asymmetrical face, has the periodical gloomy tendency of the
mother, alternating with periods of restlessness, which evince themselves
in doing unnecessarily the work of the servants and other labours
inconsistent with her husband's social status. She had at times suicidal
and homicidal impulses. She has three children; one exhibits no special
abnormality; the eldest, a boy of eleven, dislikes to play with boys
because they are rough, and plays with girls, to whom he is at times
mischievously cruel. He likes to sew and make doll's clothing and purchase
dolls, while there are other indications of sexual abnormality. The
youngest, a girl, has frequent attacks of epileptic-like fury, although
between these she is kind-hearted, good-humoured, and very affectionate.
In dealing with the question of soil, the factors predisposing to the
attacks of the parasite of malaria have to be taken into consideration;
certainly the inhabitants of certain malarial districts exhibit all the
characteristics of degenerates.
The influence of nutrition in producing nervous states likely to be
transmitted as degeneracy in the offspring are excellently illustrated in
the nervous disorders due to improper nutrition during youth. This may, as
W. S. Christopher[179] of Chicago has shown, produce all possible neuroses
to which the organism may be liable. Such neuroses relate to--
A. Psychic faculties.
B. Sensation.
1. Anaesthesia.
2. Hyperaesthesia.
3. Hyperalgia (increased pain sense).
C. Heat production.
1. Elevation of temperature.
2. Depression of temperature.
D. Muscular tissues.
1. Hypertrophy.
2. Atrophy.
3. Paralysis.
4. Convulsions.
E. Skeletal muscles.
1. General convulsions.
2. Chorea.
3. Tetany (toe and finger jerks).
F. Pharynx.
1. Dyspnoea (difficult breathing).
G. Oesophagus.
1. Dysphagia (difficult swallowing).
H. Stomach.
1. Vomiting.
2. Merycism (rumination).
I. Intestines.
1. Increased peristalsis (movement of bowel).
2. Decreased peristalsis.
J. Larynx.
1. Dyspnoea.
2. Laryngismus stridulus (croup spasm).
3. Chorea.
K. Bronchi.
1. Asthma.
2. Bronchorrhoea (excessive secretion).
L. Bladder.
1. Incontinence.
2. Retention.
M. Urethra.
1. Spasmodic stricture.
N. Uterus.
1. Neuralgias.
2. Spasms.
O. Vagina.
1. Vaginismus (painful spasm).
P. Heart.
1. Chorea.
2. Disturbance of rate.
3. Disturbance of rhythm.
Q. Secretory organs.
1. Decrease of secretion.
2. Modification of composition of secretion.
R. Absorptive organs.
S. Elaborative organs.
T. Respiratory organs. Other than those cited.
U. Excretory organs.
V. Reproductory organs.
Those of the genital organs only exist in precocious childhood, while
still others occur, some occasionally, some very frequently.
Of the psychic neuroses, perhaps the commonest are the night terrors,
which occur in ill-nourished children with great frequency. Hyperesthesia
(or increased sensitiveness) is a starvation neurosis occurring especially
in unrecognised scurvy. Variations of temperature, both increased and
subnormal, occur in children suffering from evident in-nutrition.
Of the starvation neuroses, the commonest are muscular convulsions.
Naturally enough, any muscle or any group of muscles may be affected, and
the manifestations may present all the varieties of convulsive movements
to which muscles are liable. Probably no child whose nutrition is perfect
ever has general convulsions except as the result of actual brain disease
or at the onset of some infectious process where the convulsion takes the
place of the initial chill of the adult. The so-called reflex convulsions
occur only in children whose nutrition is below par. In a rickety child
the slight irritation produced by an erupting tooth may be sufficient to
weaken the mechanism which checks explosive action, just as in the same
child it may be the determining cause of bronchorrhoea. In the healthy
child teething can cause no such effect. Both these manifestations, the
convulsions and the bronchorrhoea, are starvation neuroses. In such
children many other trivial conditions may weaken the controlling
mechanism.
In older children chorea, whatever be its cause, is evidently connected
with the developmental process. The beneficial effects in chorea of
absolute rest in bed and forced feeding are a matter of common
observation. Dysphagia as a neurosis in children is uncommon. Vomiting and
diarrhoea occur so frequently in infants from a wide variety of causes,
that it is very difficult to say when they are merely starvation neuroses.
In rickets, diarrhoea often occurs, with no adequate explanation in the
conditions present in the intestinal canal, and which is an essential
feature of the disease itself.
Laryngismus stridulus is a very common manifestation of muscular
starvation neurosis. Spasmodic asthma occurs in ill-nourished children.
Incontinence of urine in older children is often a starvation neurosis.
The younger the child the more rapid are its processes of growth. Hence in
infants the results of defective nutrition are quickly manifested, and the
curative effects of food arranged to supply the nutritive deficiencies
also become apparent very soon. In older children with more stable tissues
a defective food supply is longer borne without apparent effect; but, on
the other hand, the beneficial effect of an antidotal diet becomes
apparent only after a prolonged use.
The relatively simple diet of the infant makes it easy to discover the
particular kind of food which is supplied in sufficient quantity, and
makes the supply of the deficiency comparatively easy. But in older
children with a more varied diet the defect is less readily discovered and
less readily supplied.
The effects of climate, soil, and food in the production of degeneracy are
first shown in the causation of general loss of nerve tone in the
ancestor, often with special local expressions. This loss of nerve tone
may show itself in the offspring by any type of degeneracy from nutritive
defect to loss of moral tone.