Chapter XII: A Century of Zoology in America. Wesley R. Coe 391 (5)

Dana speaks of “the endless diversities in individuals” that compose a species, and then states that a living species, like an inorganic one, “is based on a specific amount or condition of concentered force defined in the act or law of creation.” Species, he says, are permanent, and hybrids “cannot seriously trifle with the true units of nature, and at the best, can only make temporary variations.” “We have therefore reason to believe from man’s fertile intermixture, that he is one in species: and that all organic species are divine appointments which cannot be obliterated, unless by annihilating the individuals representing the species.”

Through the activities of the French the world was prepared for the reception of evolution, and now it was already in the minds of many advanced thinkers. In 1860 Asa Gray sent to the editor of the Journal (=29=, 1) an article by the English botanist, Joseph D. Hooker, entitled “On the Origination and Distribution of Species,” with these significant remarks:

“The essay cannot fail to attract the immediate and profound attention
of scientific men.... It has for some time been manifest that a
re-statement of the Lamarckian hypothesis is at hand. We have this, in
an improved and truly scientific form, in the theories which, recently
propounded by Mr. Darwin, followed by Mr. Wallace, are here so ably
and altogether independently maintained. When these views are fully
laid before them, the naturalists of this country will be able to take
part in the interesting discussion which they will not fail to call
forth.”

Hooker took up a study of the flora of Tasmania, of which the above cited article is but a chapter, with a view to trying out Darwin’s theory, and he now accepts it. He says, “Species are derivative and mutable.” “The limits of the majority of species are so undefinable that few naturalists are agreed upon them.”

Asa Gray had received from Darwin an advance copy of the book that was to revolutionize the thought of the world, and at once wrote for the Journal a Review of Darwin’s Theory on the Origin of Species by means of Natural Selection (=29=, 153, 1860). This is a splendid, critical but just, scientific review of Darwin’s epoch-making book. Evidently views similar to those, of the English scientist had long been in the mind of Gray, for he easily and quickly mastered the work. He is easy on Dana’s Thoughts on Species, which were idealistic and not in harmony with the naturalistic views of Darwin. On the other hand, he contrasts Darwin’s views at length with those of the creationists as exemplified by Louis Agassiz, and says “The widest divergence appears.”

Gray says in part:

“The gist of Mr. Darwin’s work is to show that such varieties are
gradually diverged into species and genera through natural selection;
that natural selection is the inevitable result of the struggle for
existence which all living things are engaged in; and that this
struggle is an unavoidable consequence of several natural causes, but
mainly of the high rate at which all organic beings tend to increase.

Darwin is confident that intermediate forms must have existed; that in
the olden times when the genera, the families and the orders diverged
from their parent stocks, gradations existed as fine as those which
now connect closely related species with varieties. But they have
passed and left no sign. The geological record, even if all displayed
to view, is a book from which not only many pages, but even whole
alternate chapters have been lost out, or rather which were never
printed from the autographs of nature. The record was actually made in
fossil lithography only at certain times and under certain conditions
(i.e., at periods of slow subsidence and places of abundant sediment);
and of these records all but the last volume is out of print; and of
its pages only local glimpses have been obtained. Geologists, except
Lyell, will object to this,—some of them moderately, others with
vehemence. Mr. Darwin himself admits, with a candor rarely displayed
on such occasions, that he should have expected more geological
evidence of transition than he finds, and that all the most eminent
paleontologists maintain the immutability of species.

The general fact, however, that the fossil fauna of each period as a
whole is nearly intermediate in character between the preceding and
the succeeding faunas, is much relied on. We are brought one step
nearer to the desired inference by the similar ‘fact,’ insisted on by
all paleontologists, that fossils from two consecutive formations are
far more closely related to each other, than are the fossils of two
remote formations.

It is well said that all organic beings have been formed on two great
laws; Unity of type, and Adaptation to the conditions of existence....
Mr. Darwin harmonizes and explains them naturally. Adaptation to the
conditions of existence is the result of Natural Selection; Unity of
type, of unity of descent.”

Gray’s article was soon followed by another one from Agassiz on Individuality and Specific Differences among Acalephs, but the running title is “Prof. Agassiz on the Origin of Species” (=30=, 142, 1860). Agassiz stoutly maintains his well known views, and concludes as follows:

“Were the transmutation theory true, the geological record should
exhibit an uninterrupted succession of types blending gradually into
one another. The fact is that throughout all geological times each
period is characterized by definite specific types, belonging to
definite genera, and these to definite families, referable to definite
orders, constituting definite classes and definite branches, built
upon definite plans. Until the facts of Nature are shown to have been
mistaken by those who have collected them, and that they have a
different meaning from that now generally assigned to them, I shall
therefore consider the transmutation theory as a scientific mistake,
untrue in its facts, unscientific in its method, and mischievous in
its tendency.”

Dana, in reviewing Huxley’s well known book, Man’s Place in Nature (=35=, 451, 1863), holds that man is apart from brute nature because man exhibits “extreme cephalization” in that he has arms that no longer are used in locomotion but go rather with the head, and because he has a far higher mentality and speech. As for the Darwinian theory, the evidence, he says, “comes from lower departments of life, and is acknowledged by its advocates to be exceedingly scanty and imperfect.”

The growth of evolution is set forth in the Journal in Asa Gray’s article on Charles Darwin (=24=, 453, 1882), which speaks of the latter as “the most celebrated man of science of the nineteenth century,” and, in addition, as “one of the most kindly and charming, unaffected, simple-hearted, and lovable of men.” In regard to the rise of evolution in America, more can be had from Dana’s paper on Asa Gray (=35=, 181, 1888). Here we read, as a sequel to his Thoughts on Species, that the “paper may be taken, perhaps, as a culmination of the past, just as the new future was to make its appearance.” Finally, in this connection there should be mentioned O. C. Marsh’s paper on Thomas Henry Huxley (=50=, 177, 1895), wherein is recorded the latter’s share in the upbuilding of the evolutionary theory.

We have seen that originally Dana was a creationist, but in the course of his long and fruitful life he gradually became an evolutionist, and rather a Neo-Lamarckian than a Darwinian. This change may be traced in the various editions of his Manual of Geology, and in the last edition of 1895 he says his “speculative conclusions” of 1852 in regard to the origin of species are not in “accord with the author’s present judgment.” “The evidence in favor of evolution by variation is now regarded as essentially complete.” On the other hand, while man is “unquestionably” closely related in structure to the man-apes, yet he is not linked to them but stands apart, through “the intervention of a Power above Nature.... Believing that Nature exists through the will and ever-acting power of the Divine Being, and ... that the whole Universe is not merely dependent on, but actually is, the Will of one Supreme Intelligence, Nature, with Man as its culminant species, is no longer a mystery.”

In America most of the paleontologists are Neo-Lamarckian, a school that was developed independently by E. D. Cope (1840–1897) through the vertebrate evidence, and by Alpheus Hyatt (1838–1902) mainly on the evidence of the ammonites. They hold that variations and acquired characters arise through the effects of the environment, the mechanics of the organism resulting from the use and disuse of organs, etc. One of the leading exponents of this school is A. S. Packard, whose book on Lamarck, His Life and Work, 1901, fully explains the doctrines of the Neo-Lamarckians.

_The Growth of Invertebrate Paleontology._

How and by whom paleontology has been developed has been fully stated in the Journal in a very clear manner by Professor Marsh in his memorable presidential address of 1879, History and Methods of Palæontological Discovery (=18=, 323, 1879), and by Karl von Zittel in his most interesting book, History of Geology and Palæontology, 1901. In this discussion we shall largely follow Marsh.

The science of paleontology has passed through four periods, the first of them the long _Mystic period_ extending up to the beginning of the seventeenth century, when the idea that fossils were once living things was only rarely perceived. The second period was the _Diluvial period_ of the eighteenth century, when nearly everyone regarded the fossils as remains of the Noachian deluge. With the beginnings of the nineteenth century there arose in western Europe the knowledge that fossils are the “medals of creation” and that they have a chronogenetic significance; also that life had been periodically destroyed through world-wide convulsions in nature. From about 1800 to 1860 was the time of the creationists and catastrophists, which may be known as the _Catastrophic period_. The fourth period began in 1860 with Darwin’s Origin of Species. Since that time the theory of evolution has pervaded all work in paleontology, and accordingly this time may be known as the _Evolutionary period_.

_Mystic Period._—The Mystic period in paleontology begins with the Greeks, five centuries before the present era, and continues down to the beginning of the seventeenth century of our time. Some correctly saw that the fossils were once living marine animals, and that the sea had been where they now occur. Others interpreted fossil mammal bones as those of human giants, the Titans, but the Aristotelian view that they were of spontaneous generation through the hidden forces of the earth dominated all thought for about twenty centuries.

In the sixteenth century canals were being dug in Northern Italy, and the many fossils so revealed led to a fierce discussion as to their actual nature. Leonardo da Vinci (1452–1519) opposed the commonly accepted view of their spontaneous generation and said that they were the remains of once living animals and that the sea had been where they occur. “You tell me,” he said, “that Nature and the influence of the stars have formed these shells in the mountains; then show me a place in the mountains where the stars at the present day make shelly forms of different ages, and of different species in the same place.” However, nothing came of his teachings and those of his countryman Fracastorio (1483–1553), who further ridiculed the idea that they were the remains of the deluge. The first mineralogist, Agricola, described them as minerals—fossilia—and said that they arose in the ground from fatty matter set in fermentation by heat. Others said that they were freaks of nature. Martin Lister (1638–1711) figured fossils side by side with living shells to show that they were extinct forms of life. In the seventeenth century, and especially in Italy and Germany, many books were published on fossils, some with illustrations so accurate that the species can be recognized to-day. Finally, toward the close of this century the influence of Aristotle and the scholastic tendency to disputation came more or less to an end. Fossils were already to many naturalists once living plants and animals. Marsh states: “The many collections of fossils that had been brought together, and the illustrated works that had been published about them, were a foundation for greater progress, and, with the eighteenth century, the second period in the history of paleontology began.”

_Diluvial Period._—During the eighteenth century many more books on fossils were published in western Europe, and now the prevalent explanation was that they were the remains of the Noachian deluge. For nearly a century theologians and laymen alike took this view, and some of the books have become famous on this account, but the diluvial views sensibly declined with the close of the eighteenth century.

The true nature of fossils had now been clearly determined. They were the remains of plants and animals, deposited long before the deluge, part in fresh water and part in the sea. “Some indicated a mild climate, and some the tropics. That any of these were extinct species, was as yet only suspected.” Yet before the close of the century there were men in England and France who pointed out that different formations had different fossils and that some of them were extinct. These views then led to many fantastic theories as to how the earth was formed—dreams, most of them have been called. Marsh says:

“The dominant idea of the first sixteen centuries of the present era
was, that the universe was made for Man. This was the great obstacle
to the correct determination of the position of the earth in the
universe, and, later, of the age of the earth.... In a superstitious
age, when every natural event is referred to a supernatural cause,
science cannot live.... Scarcely less fatal to the growth of science
is the age of Authority, as the past proves too well. With freedom of
thought, came definite knowledge, and certain progress;—but two
thousand years was long to wait.”

One of the most significant publications of this period was Linnæus’s Systema Naturæ, which appeared in 1735. In this work was introduced binomial nomenclature, or the system of giving each plant and animal species a generic and specific name, as _Felis leo_ for the lion. The system was, however, not established until the tenth edition of the work in 1758, which became the starting point of zoological nomenclature. Since then there has been added another canon, the law of priority, which holds that the first name applied to a given form shall stand against all later names given to the same organism.

_Catastrophic Period._—With the beginning of the nineteenth century there started a new era in paleontology, and this was the time when the foundations of the science were laid. The period continued for six decades, or until the time of the Origin of Species. Marsh says that now “method replaced disorder, and systematic study superseded casual observation.” Fossils were accurately determined, comparisons were made with living forms, and the species named according to the binomial system. However, every species, recent and extinct, was regarded as a separate creation, and because of the usually sharp separation of the superposed fossil faunas and floras, these were held to have been destroyed through a series of periodic catastrophes of which the Noachian deluge was the last.

Lamarck between 1802 and 1806 described the Tertiary shells of the Paris basin. Comparing them with the living forms, he saw that most of the fossils were of extinct species, and in this way he came to be the founder of modern invertebrate paleontology. He also maintained after 1801 that life has been continuous since its origin and that nature has been uniform in the course of its development. Marsh adds:

“His researches on the invertebrate fossils of the Paris Basin,
although less striking, were not less important than those of Cuvier
on the vertebrates; while the conclusions he derived from them form
the basis of modern biology.”

“Lamarck was the prophetic genius, half a century in advance of his
time.”

Cuvier established comparative anatomy and vertebrate paleontology, and was one of the first to point out that fossil animals are nearly all extinct forms. He came to the latter conclusion in 1796 through a study of fossil elephants found in Europe. “Cuvier enriched the animal kingdom by the introduction of fossil forms among the living, bringing all together into one comprehensive system.” This opened to him entirely new views respecting the theory of the earth, and he devoted more than twenty-five years to developing the theories of special creation and catastrophism, described in his Discourse on the Revolutions of the Surface of the Globe. “With all his knowledge of the earth, he could not free himself from tradition, and believed in the universality and power of the Mosaic deluge. Again, he refused to admit the evidence brought forward by his distinguished colleagues against the permanence of species, and used all his great influence to crush out the doctrine of evolution, then first proposed” (Marsh).

In England it was William Smith (1769–1839) who independently discovered the chronogenetic significance of fossils, and in their stratigraphic superposition indicated the way for the study of historical geology. He first published on this matter in 1799, but his completed statements came in works entitled “Strata identified by Organized Fossils,” 1816–1820, and “Stratigraphical System of Organized Fossils,” 1817.

Invertebrate paleontology in America during the Catastrophic period had its beginning in Lesueur, who in 1818 described the Ordovician gastropod _Maclurites magna_. All of the paleontologists of this time were satisfied to describe species and genera and to ascertain in a broad way the stratigraphic significance of the fossil faunas and floras. James Hall in 1854 (=17=, 312) knew of 1588 species, described and undescribed, in the New York system, while in England Morris listed in that year 8300 Paleozoic forms. In 1856 Dana recites the known fossil species as follows (=22=, 333): The whole number of known American species of animals of the Permian to Recent is about 2000; while in Britain and Europe, there were over 20,000 species. In the Permian we have none, while Europe has over 200 species. In the Triassic we have none, Europe 1000 species; Jurassic 60, Europe over 4000; Cretaceous 350 to 400, Europe about 6000; Tertiary hardly 1500, Europe about 8000. Since that time nearly all of the larger American Paleozoic faunas have been developed, but there are thousands of species yet to be described. Who the more prominent American paleontologists of this period were has been told in the section on the development of the geological column.

The grander paleontologic results of the Catastrophic period have been so well stated by Marsh that it is worth our while to repeat them here:

“It had now been proved beyond question that portions at least of the
earth’s surface had been covered many times by the sea, with
alternations of fresh water and of land; that the strata thus
deposited were formed in succession, the lowest of the series being
the oldest; that a distinct succession of animals and plants had
inhabited the earth during the different geological periods; and that
the order of succession found in one part of the earth was essentially
the same in all. More than 30,000 new species of extinct animals and
plants had now been described. It had been found, too, that from the
oldest formations to the most recent, there had been an advance in the
grade of life, both animal and vegetable, the oldest forms being among
the simplest, and the higher forms successively making their
appearance.

It had now become clearly evident, moreover, that the fossils from the
older formations were all extinct species, and that only in the most
recent deposits were there remains of forms still living.... Another
important conclusion reached, mainly through the labors of Lyell, was,
that the earth had not been subjected in the past to sudden and
violent revolutions; but the great changes wrought had been gradual,
differing in no essential respect from those still in progress.
Strangely enough, the corollary to this proposition, that life, too,
had been continuous on the earth, formed at that date no part of the
common stock of knowledge. In the physical world, the great law of
‘correlation of forces’ had been announced, and widely accepted; but
in the organic world, the dogma of the miraculous creation of each
separate species still held sway.”

_Evolutionary Period._—This period begins with 1860 and the publication of Darwin’s Origin of Species (late in 1859). It is the period of modern paleontology, and is dominated by the belief that universal laws pervade not only inorganic matter, but all life as well. Louis Agassiz had been in America fourteen years when Darwin’s book appeared, and his wonderful influence in bringing the zoology of our country to a high stand and the further influence he exerted through his students was bound to react beneficially on invertebrate paleontology. Shortly after the beginning of this period, or in 1867, Alpheus Hyatt, one of Agassiz’s students, began to apply the study of embryology to fossil cephalopods, showing clearly that these shells retain a great deal of their growth stages or ontogeny. This method of study was then followed by R. T. Jackson, C. E. Beecher, and J. P. Smith, and has been productive of natural classifications of the Cephalopoda, Brachiopoda, Trilobita, and Echinoidea.

The dominant invertebrate paleontologist of this period was of course James Hall, who described about 5000 species of American Paleozoic fossils. He also built up the New York State Museum, while around his private collections of fossils have been developed the American Museum of Natural History in New York City and the Walker Museum at the University of Chicago. In his most important laboratory of paleontology at Albany, there have been trained either wholly or in part the following paleontologists: F. B. Meek, C. A. White, R. P. Whitfield, C. D. Walcott, C. E. Beecher, John M. Clarke, and Charles Schuchert.

In Canada, through the work of the Geological Survey of the Dominion, came the paleontologists Elkanah Billings and, later on, J. F. Whiteaves. The “father of Canadian paleontology,” Sir William Dawson, who developed independently, was active in all branches of the science and did much to unravel the geology of eastern Canada. No organism has been more discussed and more often rejected and accepted as a fossil than his “dawn animal of Canada,” _Eozoon canadense_, first described in 1865. His son, George M. Dawson, was one of the directors of the Geological Survey of Canada. Finally the extensive paleontology of the Cambrian of Canada was worked out by another self-made paleontologist, G. F. Matthew.

_Paleobotany._—American paleobotany was developed during this, the fourth period, through the state and national surveys, first in Leo Lesquereux, a Swiss student induced by Agassiz to come to America, and in J. S. Newberry. The second generation of paleobotanists is represented by Lester F. Ward and W. N. Fontaine, and the third generation, the present workers, includes F. H. Knowlton, David White, Arthur Hollick, and E. W. Berry. A new line of paleobotanical work, the histology of woody but pseudomorphous remains, has been developed by G. R. Wieland.

The grander results of the study of paleontology during the evolutionary period may be summed up with the conclusions of Marsh:

“One of the main characteristics of this epoch is the belief that all
life, living and extinct, has been evolved from simple forms. Another
prominent feature is the accepted fact of the great antiquity of the
human race. These are quite sufficient to distinguish this period
sharply from those that preceded it.”

Charles Darwin’s work at once aroused attention, and brought about in
scientific thought a revolution which “has influenced paleontology as
extensively as any other department of science.... In the [previous
period] species were represented independently by parallel lines; in
the present period, they are indicated by dependent, branching lines.
The former was the analytic, the latter is the synthetic period.”

_Synthetic Period._—What is to be the next trend in paleontology? Clearly it is to be the Synthetic period, one that Marsh in 1879 indicated in these words: “But if we are permitted to continue in imagination the rapidly converging lines of research pursued to-day, they seem to meet at the point where organic and inorganic nature become one. That this point will yet be reached, I cannot doubt.”

This Synthetic period, foreshadowed also in Herbert Spencer’s Synthetic Philosophy, has not yet arrived, but before long another great leader will appear. We have the prophecy of his coming in such books as The Fitness of the Environment, by Lawrence J. Henderson, 1913; The Origin and Nature of Life, by Benjamin Moore, 1913; The Organism as a Whole, by Jacques Loeb, 1916; and The Origin and Evolution of Life, by Henry F. Osborn, 1917.

In all nature, inorganic and organic, there is continuity and consistency, beauty and design. We are beginning to see that there are eternal laws, ever interacting and resulting in progressive and regressive evolutions. The realization of these scientific revelations kindles in us a desire for more knowledge, and the grandest revelations are yet before us in the synthesis of the sciences.

_Notes._

Footnote 3:

For more detail in regard to these tillites and the older ones see
Climates of Geologic Time, by Charles Schuchert, being Chapter XXI in
Huntington’s Climatic Factor as Illustrated in Arid America,
Publication No. 192 of the Carnegie Institution of Washington, 1914.
Also Arthur P. Coleman’s presidential address before the Geological
Society of America in 1915, Dry Land in Geology, published in the
Society’s Bulletin, 27, 175, 1916.

III
A CENTURY OF GEOLOGY.—STEPS OF PROGRESS IN THE INTERPRETATION OF LAND
FORMS

By HERBERT E. GREGORY

The essence of physiography is the belief that land forms represent merely a stage in the orderly development of the earth’s surface features; that the various dynamic agents perform their characteristic work throughout all geologic time. The formulation of principle and processes of earth sculpture was, therefore, impossible on the hypothesis of a ready-made earth whose features were substantially unchangeable, except when modified by catastrophic processes. In 1821, J. W. Wilson wrote in the Journal: “Is it not the best theory of the earth, that the Creator, in the beginning, at least at the general deluge, formed it with all its present grand characteristic features?”[4] If so, a search for causes is futile, and the study of the work performed by streams and glaciers and wind is unprofitable. The belief in the Deluge as the one great geological event in the history of the earth has brought it about that the speculations of Aristotle, Herodotus, Strabo, and Ovid, and the illustrious Arab, Avicenna (980–1037), unchecked by appeal to facts but also unopposed by priesthood or popular prejudice, are nearer to the truth than the intolerant controversial writings of the intellectual leaders whose touchstone was orthodoxy. A few thinkers of the sixteenth century revolted against the interminable repetition of error, and Peter Severinus (1571) advised his students: “Burn up your books ... buy yourselves stout shoes, get away to the mountains, search the valleys, the deserts, the shores of the seas.... In this way and no other will you arrive at a knowledge of things.” But the thoroughgoing “diluvialist” who believed that a million species of animals could occupy a 450–foot Ark, but not that pebbles weathered from rock or that rivers erode, had no use for his powers of observation.

Sporadic germs of a science of land forms scattered through the literature of the seventeenth and eighteenth centuries found an unfavorable environment and produced inconspicuous growths. Even their sponsors did little to cultivate them. Steno (1631–1687) mildly suggested that surface sculpturing, particularly on a small scale, is largely the work of running water, and Guettard (1715–1786), a truly great mind, grasped the fundamental principles of denudation and successfully entombed his views as well as his reputation in scores of books and volumes of cumbrous diffuse writing.

At the beginning of the nineteenth century a sufficient body of principles had been established to justify the recognition of an earth science, geology, and the 195 volumes of the Journal thus far published carry a large part of the material which has won approval for the new science and given prominence to American thought. From the pages in the Journal, the progress of geology may be illustrated by tracing the fluctuation in the development of fact and theory as relates to valleys and glacial features, the subjects to which this chapter is devoted.

_The Interpretation of Valleys._

_The Pioneers._

Desmarest (1725–1815) might be styled the father of physiography. By concrete examples and sound induction he established (1774) the doctrine that the valleys of central France are formed by the streams which occupy them. He also made the first attempt to trace the history of a landscape through its successive stages on the basis of known causes. His methods and reasoning are practically identical with those of Dutton working in the ancient lavas of New Mexico; and Whitney’s description of the Table Mountains of California might well have appeared in Desmarest’s memoirs.[5] The teachings of Desmarest were strengthened and expanded by DeSaussure (1740–1799), the sponsor for the term, “Geology,” (1779) who saw in the intimate relation of Alpine streams and valleys the evidence of erosion by running water (1786).

The work of these acknowledged leaders of geological thought attracted singularly little attention on the Continent, and Lamarck’s volume on denudation (Hydrogéologie), which appeared in 1802, although an important contribution, sank out of sight. But the seed of the French school found fertile ground in Edinburgh, the center of the geological world during the first quarter of the nineteenth century. Hutton’s “Theory of the Earth, with Proofs and Illustrations,” in which the guidance of DeSaussure and Desmarest is gratefully acknowledged, appeared in 1795. The original publication aroused only local interest, but when placed in attractive form by Playfair’s “Illustrations of the Huttonian Theory” (1802), the problem of the origin and development of land forms assumed a commanding position in geological thought. Hutton was peculiarly fortunate in his environment. He had the support and assistance of a group of able scientific colleagues as well as the bitter opposition of Jameson and of the defenders of orthodoxy. His views were discussed in scientific publications and found their way to literary and theological journals. Hutton’s conception of the processes of land sculpture—slow upheaving and slow degradation of mountains, differential weathering, and the carving of valleys by streams—has a very modern aspect. Playfair’s book would scarcely be out of place in a twentieth century class room. The following paragraphs are quoted from it:[6]

“... A river, of which the course is both serpentine and deeply
excavated in the rock, is among the phenomena, by which the slow waste
of the land, and also the cause of that waste, are most directly
pointed out.

The structure of the vallies among mountains, shews clearly to what
cause their existence is to be ascribed. Here we have first a large
valley, communicating directly with the plain, and winding between
high ridges of mountains, while the river in the bottom of it descends
over a surface, remarkable, in such a scene, for its uniform
declivity. Into this, open a multitude of transverse or secondary
vallies, intersecting the ridges on either side of the former, each
bringing a contribution to the main stream, proportioned to its
magnitude; and, except where a cataract now and then intervenes, all
having that nice adjustment in their levels, which is the more
wonderful, the greater the irregularity of the surface. These
secondary vallies have others of a smaller size opening into them;
and, among mountains of the first order, where all is laid out on the
greatest scale, these ramifications are continued to a fourth, and
even a fifth, each diminishing in size as it increases in elevation,
and as its supply of water is less. Through them all, this law is in
general observed, that where a higher valley joins a lower one, of the
two angles which it makes with the latter, that which is obtuse is
always on the descending side; ... what else but the water itself,
working its way through obstacles of unequal resistance, could have
opened or kept up a communication between the inequalities of an
irregular and alpine surface....

... The probability of such a constitution [arrangement of valleys]
having arisen from another cause, is, to the probability of its having
arisen from the running of water, in such a proportion as unity bears
to a number infinitely great.

... With Dr. Hutton, we shall be disposed to consider those great
chains of mountains, which traverse the surface of the globe, as cut
out of masses vastly greater, and more lofty than any thing that now
remains.

From this gradual change of lakes into rivers, it follows, that a lake
is but a temporary and accidental condition of a river, which is every
day approaching to its termination; and the truth of this is attested,
not only by the lakes that have existed, but also by those that
continue to exist.”

_Steps Backward._

Even Hutton’s clear reasoning, firmly buttressed by concrete examples, was insufficient to overcome the belief in ready-made or violently formed valleys and original corrugations and irregularities of mountain surface. The pages of the Journal show that the principles laid down by Playfair were too far in advance of the times to secure general acceptance. In the first volume of the Journal, the gorge of the French Broad River is assigned by Kain to “some dreadful commotion in nature which probably shook these mountains to their bases,”[7] and the gorge of the lower Connecticut is considered by Hitchcock (1824)[8] as a breach which drained a series of lakes “not many centuries before the settlement of this country.” The prevailing American and English view for the first quarter of the nineteenth century is expressed in the reviews in this Journal, where the well-known conclusions of Conybeare and Phillips that streams are incompetent to excavate valleys are quoted with approval and admiration is expressed for Buckland’s famous “Reliquiæ Diluvianæ,” a 300–page quarto volume devoted to proof of a deluge. The professor at Yale, Silliman, and the professor at Oxford, Buckland, saw that an acceptance of Hutton’s views involved a repudiation of the Biblical flood, and much space is devoted to combating these “erroneous” and “unscientific” views. For example, Buckland says:[9]

“... The general belief is, that existing streams, avalanches and
lakes, bursting their barriers, are sufficient to account for all
their phenomena, and not a few geologists, especially those of the
Huttonian school, at whose head is Professor Playfair, have till
recently been of this opinion.... But it is now very clear to almost
every man, who impartially examines the facts in regard to existing
vallies, that the causes now in action, mentioned above, are
altogether inadequate to their production; nay, that such a
supposition would involve a physical impossibility. We do not believe
that one-thousandth part of our present vallies were excavated by the
power of existing streams.... In very many cases of large rivers, it
is found, that so far from having formed their own beds, they are
actually in a gradual manner filling them up.

Again; how happens it that the source of a river is frequently below
the head of a valley, if the river excavated that valley?

The most powerful argument, however, in our opinion, against the
supposition we are combating, is the phenomena of transverse and
longitudinal valleys; both of which could not possibly have been
formed by existing streams.”

Phillips writes in 1829:[10] “The excavation of valleys can be ascribed to no other cause than a great flood of water which overtopped the hills, whose summits those vallies descend.”

Faith in Noah’s flood as the dominant agent of erosion rapidly lost ground through the teaching of Lyell after 1830, but the theory of systematic development of landscapes by rivers gained little. In fact, Scrope in 1830,[11] in showing that the entrenched meanders of the Moselle prove gradual progressive stream work, was in advance of his English contemporary. Judged by contributions to the Journal, Lyell’s teaching served to standardize American opinion of earth sculpture somewhat as follows: The ocean is the great valley maker, but rivers also make them; the position of valleys is determined by original or renewed surface inequalities or by faulting; exceptional occurrences—earthquakes, bursting of lakes, upheavals and depressions—have played an important part. Hayes (1839)[12] thought that the surface of New York was essentially an upraised sea-bottom modified by erosion of waves and ocean currents. Sedgwick (1838)[13] considered high-lying lake basins proof of valleys which were shaped under the sea. Many of the valleys in the Chilian Cordillera were thought by Darwin (1844) to have been the work of waves and tides, and water gaps are ascribed to currents “bursting through the range at those points where the strata have been least inclined and the height consequently is less.” Speaking of the magnificent stream-cut canyons of the Blue Mountains of New South Wales, gorges which lead to narrow exits through monoclines, Darwin says: “To attribute these hollows to alluvial action would be preposterous.”[14]

The influence of structure in the formation of valleys is emphasized by many contributors to the Journal. Hildreth in 1836, in a valuable paper,[15] which is perhaps the first detailed topographic description of drainage in folded strata, expresses the opinion that the West Virginia ridges and valleys antedated the streams and that water gaps though cut by rivers involve pre-existing lakes. Geddes (1826)[16] denied that Niagara River cut its channel and speaks of valleys which “were valleys e’er moving spirit bade the waters flow.” Conrad (1839)[17] discussed the structural control of the Mohawk, the Ohio, and the Mississippi, and Lieutenant Warren (1859)[18] concluded that the Niobrara must have originated in a fissure. According to Lesley (1862)[19] the course of the New River across the Great Valley and into the Appalachians “striking the escarpment in the face” is determined by the junction of anticlinal structures on the north with faulted monoclines toward the south; a conclusion in harmony with the views of Edward Hitchcock (1841)[17] that major valleys and mountain passes are structural in origin and that even subordinate folds and faults may determine minor features. “Is not this a beautiful example of prospective benevolence on the part of the Deity, thus, by means of a violent fracture of primary mountains, to provide for easy intercommunication through alpine regions, countless ages afterwards!” The extent of the wandering from the guidance of DeSaussure and Playfair after the lapse of 50 years is shown by students of Switzerland. Alpine valleys to Murchison (1851) were bays of an ancient sea; Schlaginweit (1852) found regional and local complicated crustal movements a satisfactory cause, and Forbes (1863) saw only glaciers.

_Valleys Formed by Rivers._

One strong voice before 1860 appears to have called Americans back to truths expounded by Desmarest and Hutton. Dana in 1850[20] amply demonstrated that valleys on the Pacific Islands owe neither their origin, position or form to the sea or to structural factors. They are the work of existing streams which have eaten their way headwards. Even the valleys of Australia cited by Darwin as type examples of ocean work are shown to be products of normal stream work. Dana went further and gave a permanent place to the Huttonian idea that many bays, inlets, and fiords are but the drowned mouths of stream-made valleys. In the same volume in which these conclusions appeared, Hubbard (1850)[21] announced that in New Hampshire the “deepest valleys are but valleys of erosion.” The theory that valleys are excavated by streams which occupy them was all but universally accepted after F. V. Hayden’s description[22] of Rocky Mountain gorges (1862) and Newberry’s interpretation of the canyons of Arizona (1862); but the scientific world was poorly prepared for Newberry’s statement:[23]

“Like the great canons of the Colorado, the broad valleys bounded by
high and perpendicular walls _belong to a vast system of erosion, and
are wholly due to the action of water_.... The first and most
plausible explanation of the striking surface features of this region
will be to refer them to that embodiment of resistless power—the sword
that cuts so many geological knots—volcanic force. The Great Canon of
the Colorado would be considered a vast fissure or rent in the earth’s
crust, and the abrupt termination of the steps of the table lands as
marking lines of displacement. This theory though so plausible, and so
entirely adequate to explain all the striking phenomena, lacks a
single requisite to acceptance, and that is _truth_.”

With such stupendous examples in mind, the dictum of Hutton seemed reasonable: “there is no spot on which rivers may not formerly have run.”

_Denudation by Rivers._

The general recognition of the competency of streams to form valleys was a necessary prelude to the broader view expressed by Jukes (1862)[24]

“The surfaces of our present lands are as much carved and sculptured
surfaces as the medallion carved from the slab, or the statue
sculptured from the block. They have been gradually reached by the
removal of the rock that once covered them, and are themselves but of
transient duration, always slowly wasting from decay.”

Contributions to the Journal between 1850 and 1870 reveal a tendency to accept greater degrees of erosion by rivers, but the necessary end-product of subaërial erosion—a plain—is first clearly defined by Powell in 1875.[25] In formulating his ideas Powell introduced the term “base-level,” which may be called the germ word out of which has grown the “cycle of erosion,” the master key of modern physiographers. The original definition of base-level follows:

“We may consider the level of the sea to be a grand base-level, below
which the dry lands cannot be eroded; but we may also have, for local
and temporary purposes, other base-levels of erosion, which are the
levels of the beds of the principal streams which carry away the
products of erosion. (I take some liberty in using the term ‘level’ in
this connection, as the action of a running stream in wearing its
channel ceases, for all practical purposes, before its bed has quite
reached the level of the lower end of the stream. What I have called
the base-level would, in fact, be an imaginary surface, inclining
slightly in all its parts toward the lower end of the principal stream
draining the area through which the level is supposed to extend, or
having the inclination of its parts varied in direction as determined
by tributary streams.)”

Analysis of Powell’s view has given definiteness to the distinction between “base-level,” an imaginary plane, and “a nearly featureless plain,” the actual land surface produced in the last stage of subaërial erosion.

Following their discovery in the Colorado Plateau Province, denudation surfaces were recognized on the Atlantic slope and discussed by McGee (1888),[26] in a paper notable for the demonstration of the use of physiographic methods and criteria in the solution of stratigraphic problems. Davis (1889)[27] described the upland of southern New England developed during Cretaceous time, introducing the term “peneplain,” “a nearly featureless plain.” The short-lived opposition to the theory of peneplanation indicates that in America at least the idea needed only formulation to insure acceptance.

It is interesting to note that surfaces now classed as peneplains were fully described by Percival (1842),[28] who assigned them to structure, and by Kerr (1880),[29] who considered glaciers the agent. In Europe “plains of denudation” have been clearly recognized by Ramsay (1846), Jukes (1862), A. Geikie (1865), Foster and Topley (1865), Maw (1866), Wynne (1867), Whitaker (1867), Macintosh (1869), Green (1882), Richthofen (1882), but all of them were looked upon as products of marine work, and writers of more recent date in England seem reluctant to give a subordinate place to the erosive power of waves. Americans, on the other hand, have been thinking in terms of rivers, and the great contribution of the American school is not that peneplains exist, but that they are the result of normal subaërial erosion. More precise field methods during the past decade have revealed the fact that no one agent is responsible for the land forms classed as peneplains; that not only rivers and ocean, but ice, wind, structure, and topographic position must be taken into account.

The recognition of rivers as valley-makers and of the final result of stream work necessarily preceded an analysis of the process of subaërial erosion. The first and last terms were known, the intermediate terms and the sequence remained to be established. A significant contribution to this problem was made by Jukes (1862).[34]

“... I believe that the lateral valleys are those which were first
formed by the drainage running directly from the crests of the chains,
the longitudinal ones being subsequently elaborated along the strike
of the softer or more erodable beds exposed on the flanks of those
chains.”

Powell’s discussion of antecedent and consequent drainage (1875) and Gilbert’s chapter on land sculpture in the Henry Mountain report (1880) are classics, and McGee’s contribution[30] contains significant suggestions, but the master papers are by Davis,[31] who introduces an analysis of land forms based on structure and age by the statement:

“Being fully persuaded of the gradual and systematic evolution of
topographical forms it is now desired ... to seek the causes of the
location of streams in their present courses; to go back if possible
to the early date when central Pennsylvania was first raised from the
sea, and trace the development of the several river systems then
implanted upon it from their ancient beginning to the present time.”

That such a task could have been undertaken a quarter of a century ago and to-day considered a part of everyday field work shows how completely the lost ground of a half century has been regained and how rapid the advance in the knowledge of land sculpture since the canyons of the Colorado Plateau were interpreted.

_Features Resulting from Glaciation._

_The Problem Stated._

Early in the nineteenth century when speculation regarding the interior of the earth gave place in part to observations of the surface of the earth, geologists were confronted with perhaps the most difficult problem in the history of the science. As stated by the editor of the Journal in 1821:[32]

“The almost universal existence of rolled pebbles, and boulders of
rock, not only on the margin of the oceans, seas, lakes, and rivers;
but their existence, often in enormous quantities, in situations quite
removed from large waters; inland,—in high banks, embedded in strata,
or scattered, occasionally, in profusion, on the face of almost every
region, and sometimes on the tops and declivities of mountains, as
well as in the vallies between them; their entire difference, in many
cases, from the rocks in the country where they lie—rounded masses and
pebbles of primitive rocks being deposited in secondary and alluvial
regions, and vice versa; these and a multitude of similar facts have
ever struck us as being among the most interesting of geological
occurrences, and as being very inadequately accounted for by existing
theories.”

The phenomena demanding explanation—jumbled masses of “diluvium,” polished and striated rock, bowlders distributed with apparent disregard of topography—were indeed startling. Even Lyell, the great exponent of uniformitarianism, appears to have lost faith in his theories when confronted with facts for which known causes seemed inadequate. The interest aroused is attested by 31 titles in the Journal during its first two decades, articles which include speculations unsupported by logic or fact, field observation unaccompanied by explanation, field observation with fantastic explanation, _ex-cathedra_ pronouncements by prominent men, sound reasoning from insufficient data, and unclouded recognition of cause and effect by both obscure and prominent men. With little knowledge of glaciers, areal geology, or of structure and composition of drift, all known forces were called in: normal weathering, catastrophic floods, ocean currents, waves, icebergs, glaciers, wind, and even depositions from a primordial atmosphere (Chabier, 1823). Human agencies were not discarded. Speaking of a granite bowlder at North Salem, New York, described by Cornelius (1820)[33] as resting on limestone, Finch (1824)[34] says: “it is a magnificent cromlech and the most ancient and venerable monument which America possesses.” In the absence of a known cause, catastrophic agencies seem reasonable.

_The Deluge._

In the seventh volume of the Journal (1824)[35] we read:

“After the production of these regular strata of sand, clay,
limestone, &c. came a terrible irruption of water from the north, or
northwest, which in many places covered the preceding formations with
diluvial gravel, and carried along with it those immense masses of
granite, and the older rocks, which attest to the present day the
destruction and ruin of a former world.”

Another author remarks:

“We find a mantle as it were of sand and gravel indifferently covering
all the solid strata, and evidently derived from some convulsion which
has lacerated and partly broken up those strata....”

The catastrophe favored by most geologists was floods of water violently released—“we believe,” says the editor, “that all geologists agree in imputing ... the diluvium to the agency of a deluge at one period or another.”[36] Such conclusions rested in no small way upon Hayden’s well-known treatise on surficial deposits (1821),[37] a volume which deserves a prominent place in American geological literature. Hayden clearly distinguished the topographic and structural features of the drift but found an adequate cause in general wide-spread currents which “flowed impetuously across the whole continent ... from north east to south west.” In reviewing Hayden’s book Silliman remarks:

“The general cause of these currents Mr. Hayden concludes to be the
deluge of Noah. While no one will object to the propriety of ascribing
very many, probably most of our alluvial features, to that
catastrophe, we conceive that neither Mr. Hayden, nor any other man,
is bound to prove the immediate physical cause of that vindictive
infliction.

We would beg leave to suggest the following as a cause which _may_
have aided in deluging the earth, and which, were there occasion,
_might_ do it again.

The existence of enormous caverns in the bowels of the earth, (so
often imagined by authors,) appears to be no very extravagant
assumption. It is true it cannot be proved, but in a sphere of eight
thousand miles in diameter, it would appear in no way extraordinary,
that many cavities might exist, which collectively, or even singly,
might well contain much more than all our oceans, seas, and other
superficial waters, none of which are probably more than a few miles
in depth. If these cavities communicate in any manner with the oceans,
and are (as if they exist at all, they probably are,) filled with
water, there exist, we conceive, agents very competent to expel the
water of these cavities, and thus to deluge, at any time, the dry
land.”

The teachings of Hayden were favorably received by Hitchcock, Struder, and Hubbard, and many Europeans. They found a champion in Jackson, who states (1839):[38]

“From the observations made upon Mount Ktaadn, it is proved, that the
current did rush over the summit of that lofty mountain, and
consequently the diluvial waters rose to the height of more than 5,000
feet. Hence we are enabled to prove, that the ancient ocean, which
rushed over the surface of the State, was at least a mile in depth,
and its transporting power must have been greatly increased by its
enormous pressure.”

Gibson, a student of western geology, reaches the same conclusion (1836):[39]

“That a wide-spread current, although not, as imagined, fed from an
inland sea, once swept over the entire region between the Alleghany
and the Rocky Mountains is established by plenary proof.”

Professor Sedgwick (1831) thought the sudden upheaval of mountains sufficient to have caused floods again and again. The strength of the belief in the Biblical flood, during the first quarter of the 19th century, may be represented by the following remarks of Phillips (1832):[40]

“Of many important facts which come under the consideration of
geologists, the ‘Deluge’ is, perhaps, the most remarkable; and it is
established by such clear and positive arguments, that if any one
point of natural history may be considered as proved, the deluge must
be admitted to have happened, because it has left full evidence in
plain and characteristic effects _upon the surface of the earth_.”

However, the theory of deluges, whether of ocean or land streams, did not hold the field unopposed. In 1823, Granger,[41] an observer whose contributions to science total only six pages, speaks of the striæ on the shore of Lake Erie as

“having been formed by the powerful and continued attrition of some
hard body.... To me, it does not seem possible that water under any
circumstances, could have effected it. The flutings in width, depth,
and direction, are as regular as if they had been cut out by a
grooving plane. This, running water could not effect, nor could its
operation have produced that glassy smoothness, which, in many parts,
it still retains.”

Hayes and also Conrad expressed similar views in the Journal 16 years later.

The idea that ice was in some way concerned with the transportation of drift has had a curious history. The first unequivocal statement, based on reading and keen observation, was made in the Journal by Dobson in 1826:[42]