Nature and man in America

Introduction

Modern science unhappily appears to be in conflict with the religious traditions of our race. The development of our knowledge of Nature has led to a loss cf the old confidence in the conditions of human life. Our fathers rejoiced in the conviction that they came directly from the Creator’s hands. It is now evident to us that our being is due to what we term more natural causes, — that man’s body has been slowly evolved from the earth, passing onward through inconceivable stages, each leading upward from the level of the lowest organic life.

Disguise it as we may, there can be no question that Science has taken much from our heritage of ancient ideals. What can it give in place of the confidence which it has destroyed ? Though as yet the scientific study of Nature has been in the main destructive as regards the ideal foundations of our life, it is my belief that this branch of learning can and will give a great deal to replace that which it has overthrown. Half a century ago, Science appeared as the destroyer of faith and trust in the universe. It seems to me that we now are approaching the time

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when our knowledge will reaffirm the old belief which our fathers had in the essential control of a beneficent Providence. With each advance in our knowledge concerning the conditions which have brought men to their present estate, we come to a fuller sense as to the order and system by which the processes of Nature have made men what they are. There is reason to hope that the faith of our children may be like unto that of our fathers, — better, indeed, than the old faith, for it will rest on the firm foundations of our own knowledge, rather than on the trust in the opinions of our elders.

It seems to me to be the duty of every naturalist, particularly when he has adopted the tasks of the teacher, to use each fit occasion to show wherein he finds proof of a just confidence as to the relations of man to the creative power which works in Nature. By so doing, he may hope to help himself and his fellow-students to escape from the perplexity which has been brought about through the revolution in the opinions of men which modern science has induced. With this end in view, I shall devote the first four chapters of this book to a general statement concerning the effect of critical conditions of the earth on the development of organic life in general. It will be my aim to show that geographic changes and the consequent revolutions of the climate which our earth has undergone, though rude and in a way destructive, have nevertheless served the best uses of life, driving

INTRODUCTION.

Vll organic creatures by the whips of necessity upward and onward toward the higher planes of being.

I shall give the latter half of this essay to the discussion of geographic influences upon man, endeavoring to show, at least in a general way, how the development of race peculiarities has been in large part due to the conditions of the stage on which the different peoples have played their parts.

I shall endeavor to trace in outline the effect of the geographic conditions on the development of peoples in the past, and to make a somewhat careful study of these problems as they are exhibited in North America.

Although we all feel an interest in mankind considered as a whole, we particularly desire to know, with all the foresight which the study of natural laws may afford, the fate of our own descendants on this earth ; and because to each of us our land is the dearest, we wish above all to foresee the future of the nation to which we give our best hopes. Therefore I shall endeavor to trace the probable future of the social and economic development of North America in a somewhat detailed way, endeavoring in the sketch to indicate the manner in which the geographic features of the continent have controlled the settlement and development of the populations up to the present time, and the probable influence of those conditions on the future of our race.

While this work is to be divided into two parts, —

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one concerning the influence of environment on organic life, and the other concerning the conditions of man in North America, — the subject matter is really a unit. The life before man has afforded the conditions of his being; and the lower kindred in animal and plant are still the ministers of his days, mediators between his own station and the mineral world below. Whenever we seek to account for the state of any organic phenomena, whether it be such as are exhibited by the lowest animal or by our own species, it is necessary to select some particular part of the creature’s conditions, and for the time to devote our attention solely to the problems which it affords. The result of this method of study is necessarily to give us a somewhat one-sided view of the matter. In all divisions of the natural field, the effects of many causes are inextricably intermingled. The consideration of any one of them can give us only a limited and one-sided aspect of its true nature. Therefore, in reading these pages the student should bear in mind the fact that we are considering only one of the many series of influences which have affected the life of man. He may also advantageously bear in mind the fact that the phenomena of inheritance which are ever contending against the immediate influences of environment are scantily considered in the following pages. They are here and there mentioned; but to give them their true weight it would be necessary greatly to increase the size of the book, and with the result that the element .

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IX of unity, which comes with the consideration of a single series of causes, would be lost.

Although this book is designed in part for the use of the general reader who wishes to obtain some slight idea as to the trend of that modern science which takes account of the relation of organic life to its environment, it is particularly designed for the use of beginners in the study of geology. So vast is the body of fact in the records of our earth-science that it is hard for the student to secure any general conceptions which may serve to guide his efforts in the ac-

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quisition of detailed information. Although in general, large views can best be attained by those who have already acquired a great store of detailed knowledge, it is well for the student at the outset to obtain some general conception as to the direction of scientific inquiry. With such suggestions, he can make good use of the information which he secures from textbooks and other sources of knowledge which are open to him.

It should be said that the greater part of the matter contained in this work was first prepared for a course of lectures before the Lowell Institute in Boston. The last four chapters were printed in “ Scribner’s Magazine,” in the year 1890. Considerable additions to the text have been made during its preparation for the present form of publication.

Cambridge, Mass., Sept. 1891.

Chapter I. Page

Ancient View as to the Relation of Man to the Earth. — Effect of Study of Paleontology. — Work of Cuvier; of Agassiz. — Animals and Plants of North America. — Relative Advance of Life on the several Continents. — Comparison of Organic Life of Europe with that of other great Lands. — Effect of Geographic Changes. — Comparison of Asiatic and Australian Life. — Effect of Mountain Barriers; of Migrations of Men. — Geographic Influences of Cape Cod; of the Gulf Stream. — Probable Effect of opening depressed Areas of the Sahara to the Sea. — Comparison of Mountains and Plains. — Effects of difficult Conditions on Advance of Life. — Comparison of Tropical and Polar Conditions 1

Chapter II

Nature and Origin of Continents. — Effect of Continents on Seas. — Interaction of Sea and Land. — Salinity of Ocean and Dead Seas.

— Transportation of Material from Land to Sea. — Effect of Volcanoes.— Possible Effect arising from Destruction of Continents.

— Effect of Sea and Land on Organic Life ; Conditions of Passage of Life from Sea to Land. — Brief Statement as to Development of Life. — Effect of Mountain Growth ; Absence of such Structures on the Sea Floor. — Relations of Mountains to Continental Growth.

— Effect of Mountains on North America. — Movements of Subterranean Materials in the Process of Mountain-Building .... -32

Chapter III

Permanence of Continents ; Evidence that their Areas have been Sea Floors. — Evidence of slow Growth of Mountains. — Proof that the Continents are ancient. — Evidence from Organic Life ; from the Physical Structure of Sediments. — Devonian Black Shale. — Continental Shelf; Conditions of its Formation. — Progressive Ad-

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vance in Development of the Continent from Cambrian Time to the present Day. — Successive Positions of Shore-line. — Variations in the Form of Continent; Subsidence during Glacial Period in Northern Portion; corresponding Uplift in Southern Portion.

— Evidence from the West Indies Islands ; from Florida Rocks. — Summary 66

Chapter IV

The Nature of Faunae and Florae. — Migration of these Organic Armies. — Individualization of Continents. — Condition of Faunae and Florae in Cambrian Time; in Successive Periods. — Effect of Growth of Mountains; Effect of Elevation at Beginning of Coal-measures. — Croll’s Hypothesis of Climate Change. — Conditions of Continental Growth in Europe. — Influence of Geographic Conditions on the Development of Life. — Conditions of last Glacial Period. — Relation of Continents to Marine Currents. — Uniform Growth of the Earth’s Features. — Uniformity in Condition of Atmosphere. — Climatal Variations ; Delicacy of Adjustment thereof; its Measure. — Effect of Variations of Gulf Stream on Extension of Ice. — Review and Conclusion 108

Chapter V

Dependence of Man on Environment; Increase of this Dependence with the Advance of Civilization. — Relations of our modern States to the Conditions of the Earth. — Advance in the Sj’mpathetic Motive. — Comparison of Europe and North America. — Discussion of the separate Areas of Europe. — Isolation of Great Britain; its Causes. — Isolated Areas of Asia. — Cradle-land of the Aryan People. — Permanence of Race Qualities. — Race Qualities in Africa ; in Australia ; in America. — Geographic Conditions of North America; Review of the several Fields of this Continent.— Effect of Physical Conditions of North America on native Indians 547

Chapter VI

Geographic Relations of North America; Variations of these Relations in former Geologic Periods. — Peculiar Fitness of North America for the Nurture of Plant Life; Inferior Position of its Animals. — Contributions of North America to the Domesticated Animals and Plants of Civilization. — Relative Measure of Relation

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of North America with Europe and with Asia. — Origin of North American Indians. — Conditions of first Settlement by Man. Condition of American Indians when the Country was first settled by the Whites. —Effect of the Buffalo on the Habits of Indians; Region of Prairies. — Settlement of America by Europeans; Conditions which led thereto. — Scandinavian, Spanish, French, and English Settlements. —Importance of Geographic Features in determining Success of the various Colonies; Effect of the Appalachian Barrier. — Influence of the St. Lawrence and Mississippi Rivers. _ Influence of the Tobacco Plant. — Settlement of the Mississippi Valley; Effect of the Geographic Conditions therein . . 174

Chapter VII

Effect of the Appalachian Mountain System on the Distribution of Slavery. — Influence of the Prairies ; Rapidity and Ease with which they are won to Tillage. — Effect of Invention of Agriculture. — Original Division of North America. — Atlantic Coast ; its Agricultural Capacity. — Mississippi Valley and Pacific Arable Land. —

Effect of Modern Economies in producing local Peculiarities of Society.— Lack of Geographic Variety in North America. — Three Marine Regions of this Continent. — Details of the New England District; Surface Tillable Soils; Variety of Occupations. — New York District ; Comparison of its Resources with those of New England. — Virginia District. — Absence of Glacial Erosion; Influence of Blue Ridge ; Character of Plain Country; Condition of Population. — Effect of Diverse Climates on the Negroes. — Florida Peninsula; its Soils; Shore-Line Fisheries; probable Future of the District. — Mexican Gulf Group of States; Region of the Lowlands; Climate; Mineral Resources; probable Increase of Negro Population. — Ohio Group of States; Climate; Soil; Contrasts in Fertility; Effect of these Contrasts on the People; Influence on the Civil War. — District of the Great Lakes ; Peculiarities of the Region ; Climate; Variety of Mineral Resources 208

Chapter VIII

Section of North America west of the Mississippi. — Division into Sections as determined by Rainfall. — Aridity of the District; probable Future. — Central District of Canada. — Region of the Red River; Condition of Climate; Fitness for the Use of European Settlers. — Rocky Mountain District ; Effect of Corrlilleran Barrier. — Condition of Cordilleran District in northern Mexico; within the United States; Form of the Mountains; Recent Change in the

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Rainfall; Character of Soil; Variation in Climate. — Mining Industry of Cordilleran District; Variety of Resources; Fitness of Region for Aryan Race. — Pacific Coast District; Division into Three Areas. — Section of southern California. — Relation of Mining and Tillage Fields. — District of Oregon; Mineral Resources;

Soil; Climate; Fitness for Aryan Race. — Alaskan District. — Effect of American Conditions on the Life of Europeans ; on Africans.— Evidence of Longevity of Europeans; from Surgery; from Field Sports; from Measurements. — Endurance of Soldiers in Civil War. — Effect of American Climate on Negroes. — Conclusion . . 250

NATURE AND MAN IN AMERICA.

Chapter I

Ancient View as to the Relation of Man to the Earth. — Effect of Study of Paleontology. — Work of Cuvier; of Agassiz. — Animals and Plants of North America. — Relative Advance of Life on the several Continents.

— Comparison of Organic Life of Europe with that of other great Lands. — Effect of Geographic Changes. — Comparison of Asiatic and Australian Life. — Effect of Mountain Barriers; of Migrations of Men.

— Geographic Influences of Cape Cod; of the Gulf Stream. — Probable Effect of opening depressed Areas of the Sahara to the Sea. — Comparison of Mountains and Plains. — Effects of difficult Conditions on Advance of Life. — Comparison of Tropical and Polar Conditions.

Our forefathers looked upon the earth as an inert mass, upon which life had been imposed by the will of a superior being. To them the earth was essentially lifeless ; here and there portions of its matter sprang into a plane of higher existence, in animal or plant, to fall back after a brief time into the inert soil. Now and then a philosopher attained to a deeper sense of the relations between the living and the dead parts of the earth. Thus Pythagoras and his school conceived that the fossils of the rocks represented a certain striving of the earthy matter to become living. They thus recognized the essential vitality of the earth ; they supposed the particles of

NATURE AND MAN IN AMERICA.

matter to be spontaneously seeking a higher state of organism. But the conception of the earth as inert held in the minds of naturalists even down to our own generation. Only in the divine Kepler do we find a philosopher strong enough to conceive this sphere as essentially organized. To him this world is so endowed with activities that it is to be accounted alive. In his reflections on the order of Nature, he holds to the doctrine that the earth is animated in the fashion of an animal ; he finds in the tides an evidence of its slow breathing.

Critics have found in this fancy of Kepler proof of a disordered mind, of an imagination which outran the limits of scientific inquiry ; but though there is an element of ideality or even of wild fancy in his speculations as to the nature of the earth, it seems likely that his divining imagination brought him clearer to the truth than the hard-mindedness of other naturalists.

In this and the following chapters I propose in outline to trace, as far as the present state of our knowledge will permit, the connection between the functions of our planet and the development of organic life upon it. I hope to show that the apparently rude and massive machinery of our earth has so operated during great periods of geologic time as to nurse and develop the organic life which inhabits its surface. Under my subject, I propose to include the evident natural forces which can have an influence on organic beings, the features in our earth’s

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history which determine the conditions of soil and climate ; in a word, those complicated influences to which we give the name of Environment.

In seeking to find our way to an understanding of the relations between the earth and its living inhabitants, we must first bear in mind the fact that we are fighting against an ancient prejudice. Almost instinctively we look upon the living being as something essentially foreign to the earth upon which it is set; the ever present fact of death, the return of the individual to the dust, accents this relation which ancestral habits of thought have fixed in our understanding. As the first step toward this larger view of Nature, I propose to consider the stages of an inquiry which led me many years ago to combat in my lectures to students the prejudice which I seek to do away with. Although the problem is one of many details and required some years for its solution, it can be readily apprehended, for the reason that it involves only simple considerations.

When naturalists began to study the fossils buried in the rocks of the earth’s crust, they soon learned that while the newer deposits contained forms which were closely akin to those now dwelling on the earth, the more ancient strata held the remains of animals and plants essentially different from those now living. As long ago as the beginning of the eighteenth century, Dr. Robert Hooke suggested that it might be possible to determine the relative age of strata

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in different regions by the consideration of these organic remains, or, as he expressed it, “we might raise a chronology from the study of these medals of creation. ” It was not, however, until the beginning of the nineteenth century, or one hundred years after Hooke’s prophetic conjecture, that this chronological study of the rocks through their fossils was actually begun. The first steps in this great work of unravelling the earth’s past history were taken by the illustrious Cuvier.

Cuvier and his immediate followers conceived that the ancient sedimentary deposits each contained assemblages of fossils which were alike in all the rocks of a given age. They supposed that the fossils of the Trias or of the Miocene which were found in England or in France would likewise be found in deposits of that age in every part of the world whatsoever. Gradually, however, as our knowledge of the animals and plants now living became more complete, it was perceived that the present life of the planet is divided into limited realms, — faunae and florae, as naturalists term them. Thus, to take the most conspicuous instance, the living animals and plants of Australia differ surprisingly from those of any other continent, there being but few of the thousand indigenous species of that island continent which are represented by kindred forms in other lands. So it came first to be conjectured, and afterward to be proved, that the life of the past had a regional division somewhat like that which we find to exist at the

NATURE AND MAN IN AMERICA.

present time. Slowly geologists came to see that they could not expect the Miocene of Europe or the Trias of that country to contain just the same forms which characterize those beds in the other continents.

The next step in the development of this idea was taken by my master, Louis Agassiz. Although the elder Agassiz is best known as a zoologist and geologist, he had a considerable acquaintance with botany, which he mainly derived from his association as a student with the distinguished Dr. Braun, afterward professor of botany at Berlin. Agassiz’s wideranging geological studies brought him at an early age in contact with the deposits of the Miocene tertiary in Switzerland. These beds contain an amazing number of fossil leaves, shed in the autumns of former ages, and buried in ancient lake-beds of Switzerland. The perfection of these fossils is singular. They are often so well preserved that we miss nothing but the hue which characterized them when they fell.

When Agassiz came to America in 1846, his observant eye noticed the fact that while our American forests were singularly unlike those now existing in Europe, they were very closely related to the woods which had covered central parts of that continent in the Miocene time. At present the forests of Europe contain a small number of species of trees compared with those of North America. Thus, while in North America we have about thirty-five species of oaks, in Europe there are not more than four indigenous

NATURE AND MAN IN AMERICA.

species of that group. Moreover, in North America there are many forms, such as our sassafrases, sweet gums, sour gums, tulip-trees, magnolias, bald cypresses, etc., which are no longer found in European woods. Agassiz noted the fact that the greater part of these genera which are now peculiar to North America were in Miocene day characteristic of Europe. In other words, the forests of the European held were once like those of North America; but the Old World has passed by that stage in its arboreal development. Little survives of that period in its history save the fossils in the rocks.

Agassiz went further with his inquiry. He found that a good many animals now living in North America, such as our opossums, many of our fishes, and some of our reptilian group, also survived in North America, though they had vanished from the Old World. This series of facts remained a subject of recurrent inquiry with Agassiz; and in 1860 he called my attention to the matter, and bade me make a further study as to their meaning.

Following the lead which my master gave me, I proceeded to make tables, which would set forth these peculiar differences in the rate of advance of North America and Europe, and to extend the tabulation to the other continents. From the data thus gathered, it soon became evident that this peculiarity was not limited to Europe and North America, but that the stage of advance of life differed for each continent. Taking European life for our standard, and inquiring into the conditions of organic development on the other continents, it becomes evident that Europe had gone farther forward in its organic history than any other land. Thus, in the case of Asia, we find there now living many genera of plants and animals the species of which had formerly existed in Europe, but had disappeared from that land. Elephants, tigers, and many other animals, abundant in Europe in the later Tertiary, but no longer present, still abound in Asia. Africa has yet more archaic assemblages of animals and plants; that is to say,

on the African continent there are more forms the kindred of which once existed in Europe, but have passed away. Pursuing the results of our series, we find that the organic life of South America is lower in grade than that of the continents before mentioned ; while Australia is last of all in the measure of elevation of its life. In a very general way, we may say that the life of North America has lagged behind that of Europe by something like the amount of one geological period; Asia is behind by about the same term ; Africa is yet farther behind in the race; and finally, Australia has an assemblage of animals which remind us more closely of Europe in the Jurassic time than Europe of to-day. We cannot take up the organic species of the continents in detail, but we may note the fact that the native mammals or suck-giving animals of Australia all belong to the group ol Marsupials or pouch-bearers, — forms which in Europe appear to have passed away, or at least to have lost their importance at the beginning of the Cretaceous period.

When we come to tabulate the facts, we find that the other continents are characterized by a rate of advance in their organic life which puts them in the following series: Europe at the head of the great procession; next following and in nearly equal advance the continents of Asia and North America; farther in the rear comes Africa; South America is yet farther behind; and far behind the others, the laggard among all the lands, the slow-going continent of Australia.

If the general facts indicated in these considerations came to us through observations made upon any single group of animals or plants, it would have little interest, for it might be supposed to fall into the field of the inexplicable or at least unexplained things, the realm we term Chance ; but the statement as to the relative. advance of the life on the several continents is true for a great many separate groups. In a general way, it is true of plants, of mollusca reptiles, of fishes, and of mammals. The coincidence in the rate of development of these distinct groups of beings was sufficient to make me hopeful of finding some clew to the cause of the perplexing facts.

It is the habit of naturalists to avoid prolixity by giving their readers only the results of their inquiries, leaving out of consideration the steps by which they attained their successes or failures in the work of research. It seems to me, however, worth while

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to set forth the method which I found myself driven to pursue in my effort to get some further account as to the causes which led to these peculiar conditions in the distribution of organic beings.

When a naturalist has attained the state of inquiry to which we have now come in the statement of our problem, he needs to beat the brush of fact and fancy in order to get a clew for further search. If he has been well taught or has profited by individual experience, his next step will be to search in the realm of Nature for some series of facts which are in any way coincident with those which he seeks to explain. It is evident at the outset of this particular inquiry after new series of facts to be used in comparison with those in hand, that this difference in the rate of development of life on different continents may be in some way connected with the physical history of the continental masses themselves. Now, the only way to take up the physical history of continents, since we know that history as yet most imperfectly, is to make a study of their existing shapes. The geologist already knows full well that the actual shape of the continental form has been determined by the experiences of that land-mass in the past. The land is what it is because of the various shapegiving influences which have worked upon it. With this general thought in mind, we may proceed to the next step of the inquiry.

It is impossible for any one to grasp the form of a continent in its entirety. It is true that every hill

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and valley, every outline of surface, however trifling, indicates some part of the history of that land ; but the mass of fact is so great that it is beyond the compass of the mind to grasp it firmly. We must therefore find, if possible, some simple index of the continental form, sufficiently clear and general in its nature to be taken into the understanding. This index, as we shall shortly see, lies ready for us in the simple, readily recognizable feature, — the shore-line. Long ago Ritter and afterward Guyot recognized the fact that the amount of shore-line of the several continents in proportion to their internal square-mile area varies greatly, as is shown by the proportionate area of the peninsulated appendages to the solid mass of the lands with which they are united; this is in Europe one to four, in Asia one to six, in North America one to fourteen. The other continents have so few peninsulas that no definite ratios can be established. Europe has by far the largest amount of shore in proportion to its square-mile area of any of the continents; Asia and North America have much less shore-line for their square-mile surface; Africa yet less ; while South America and Australia come still lower in the scale. To establish these ratios in the form in which I have presented them, it is desirable to reduce the continents to the same areas, and then to compare their shore- lines.

No sooner do we grade the continents by the proportion of shore -line to square mile of surface, and place this tabulation against that which shows the series in organic development, than we are startled to find that in a general way at least the two sets of facts correspond. Although the parallelism is by no means perfect, it is sufficient to give the naturalist the clew which he seeks to obtain.