CHAPTER VIII. Climate, Soil, and Food

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, 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.

The alleged transformation of the British into the Yankee is commonly cited in illustration of the supposed effects of soil and climate. Three decades 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 fossæ 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, 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.

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 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, 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 anæmia." 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 anæmia 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. 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 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, 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, 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 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. Anæsthesia. 2. Hyperæsthesia. 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.