Our author then adds this summary of his argument:
"The extremely fresh condition of the bones, proved by the retention of so large a proportion of animal matter, and the fact that animals of all ages were involved in the catastrophe, shows that the event was geologically, comparatively recent, as other facts show it to have been sudden."
That it must have been a good deal more "sudden" than even this author will admit, is evident from the nature of the hippopotamus. I never thought that it was particularly afraid of the water, or likely to be drowned by any such moderate catastrophe as Prestwich invokes in this singular volume. The reader must, however, note that this affair, like the entombment of the mammoth, certainly =took place since man was upon the globe=, even according to the uniformitarians. Would it not be economy of energy to correlate the two together? But if man dates from "Miocene times," as some contend, he must have witnessed half a dozen awful affairs like these, for there is scarcely a country on the globe that has not been under the ocean since then.
Let us proceed.
But whither shall we turn to avoid finding similar phenomena? The vast deposits of mammals in the Rocky Mountains may occur to the reader. As Dana says, they "have been found to be literally Tertiary burial grounds." I need not go into the details of these deposits, nor of those in other places containing the great mammals which must have been contemporary with "Tertiary man," for I would only weary the reader with a monotony of abnormal conditions of deposit--unlike anything now being produced this wide world over. We shall be stating the case very mildly indeed, if we conclude that the vast majority of the fossils, by their profuse abundance and their astonishing preservation, tell a very plain story of "speedy burial after death," and =are of an essentially different character= from modern deposits.
Prof. Nicholson, in speaking of the remains of the Zeuglodon, says:
"Remains of these gigantic whales are very common in the "Jackson beds"
of the Southern United States. So common are they that, according to Dana, "the large vertebrae, some of them a foot and a half long and a foot in diameter, were formerly so abundant over the country in Alabama that they were used for making walls, or were burned to rid the fields of them.""[66]
Shortly before his death in 1895, Dana prepared a revised edition of his "Manual," and in it he gives us quite a rational explanation of this case, as follows:
"Vertebrae were so abundant, on the first discovery, in some places that many of these Eocene whales must have been stranded together in a common catastrophe, on the northern borders of the Mexican Gulf--possibly by a series of earthquake waves of great violence; or by an elevation along the sea limit that made a confined basin of the border region, which the hot sun rendered destructive alike to Zeuglodons and their game; or by an unusual retreat of the tide, which left them dry and floundering under a tropical sun." (p. 908.)
That is, this veteran geologist in his old age would not attempt to account for such abnormal conditions without a catastrophe of some kind.
But if we use similar explanations for similar conditions, where shall we stop through the whole range of the rocks from the Cambrian to the Pleistocene?
Dana became very fond of this idea of earthquake waves, and invoked them to account for "the universality and abruptness" with which the species disappear at the close of "Palaeozoic time," using as the generating cause the uplifting of the Appalachian Mountains, with "flexures miles in height and s.p.a.ce, and slips along newly opened fractures that kept up their interrupted progress through thousands of feet of displacement,"
from which he says "incalculable violence and great surgings of the ocean should have occurred and been often repeated.... Under such circ.u.mstances the devastation of the sea border and the low-lying lands of the period, the destruction of their animals and plants, would have been a sure result. The survivors within a long distance of the coast line would have been few."[67]
But as this sudden break in the life-chain "was so general and extensive that no Carboniferous species is known to occur among the fossils of succeeding beds, not only in America and Europe, but also over the rest of the world" (p. 735), he is obliged to make his catastrophe by earthquake waves positively =world wide=. Hence he adds: "The same waves would have swept over European land and seas, and there found coadjutors for new strife in earthquake waves of European origin."
At the close of the Mesozoic he uses similar language, though in this case he has the whole range of the mountains on the west of both North and South America, the Rockies and the Andes, in length a "third of the circ.u.mference of the globe," "undergoing simultaneous orogenic movements, with like grand results." (p. 875.) "The deluging waves sent careering over the land" would, he thinks, "have been destructive over all the coasts of a hemisphere," and "may have made their marches inland for hundreds of miles" (p. 878), sweeping all before them.
I should think so; but then what becomes of this doctrine of uniformity?
Personally, I have not the slightest objection to these "deluging waves sent careering over the land," for I feel sure that just such things have occurred, and on just such a scale as our author pictures, for, as he says, the destruction of species "was great, =world-wide=, and one of the most marvelous events in geological history." (p. 877.)
But it seems to me that here we have an enormous amount of energy going to waste. Others have demanded a continent to explain the appearance of a beetle in a certain locality; but here we have a great world-wide catastrophe to explain the sudden disappearance of merely a few species.
Why not utilize this surplus energy in doing other necessary work, that has certainly been accomplished somehow, but has. .h.i.therto gone a-begging for a competent cause? The only thing I object to in Dana"s view of the case is his way of having these "exterminations" take place on the installment plan. For in that way we have to work up a great world catastrophe to do only a very limited amount of work, and then have to repeat the thing another time for a similarly limited work, =when one such cosmic convulsion is competent to do the whole thing=. I plead for the "law of parsimony," and the economizing of energy.
The vast shoals of carca.s.ses which seem to be piled up in almost every corner of the world are _prima facie_ evidence that our old globe has witnessed some sort of cosmic convulsion. The exact cause, nature, and extent of this event we may never have sufficient facts to determine, though two or three additional facts having a bearing on the subject will be considered in the following chapters.
FOOTNOTES:
[55] "Manual," p. 229.
[56] _Pop. Sci. Mo._, Vol. xxi, pp. 143, 693.
[57] "Manual," p. 141.
[58] "Geol. and Min.," Vol. I., pp. 124-5. Ed. 1858.
[59] "Theoretical Geol.," p. 265. London, 1834.
[60] "Old Red Sandstone," pp. 48, 221-2.
[61] _Pop. Sci. News_, May, 1902, pp. 106-7.
[62] "Histor. Geol.," p. 53.
[63] "Acadian Geol.," p. 260.
[64] "Mammals," p. 430.
[65] "On Certain Phenomena, etc.," pp. 50-52.
[66] "Ancient Life-History," p. 300.
[67] "Manual," p. 736.
CHAPTER X
CHANGE OF CLIMATE
Another great general fact about the fossil world may be stated about as follows:
=All of the fossils= (save a very few of the so-called "Glacial Age,"
and they admit of other easy explanation) =give us proofs of an almost eternal spring having prevailed in the Arctic regions, and semi-tropical conditions in north temperate lat.i.tudes; in short give us proofs of a singular uniformity of climate over the globe which we can hardly conceive possible, let alone account for.=
The proofs of this are almost unnecessary, as this subject of climate has been pretty well discussed of late years. And it was the overwhelming evidence on this point which forced Lyell and so many others to decide against the theory of Croll, which called for a regular rotation of climates, for they said that the fossil evidence was wholly against such a view. Howorth has given an admirable argument on this point in Chapter XI of his second work on the Glacial Theory[68] and to it I would refer the reader for details which I have not the s.p.a.ce to reproduce here.
This author first remarks:
"The best thermometer we can use to test the character of a climate is the flora and fauna which lived while it prevailed. This is not only the best, but is virtually the only thermometer available when we inquire into the climate of past geological ages. Other evidence is always sophisticated by the fact that we may be attributing to climate what is due to other causes; boulders can be rolled by the sea as well as by sub-glacial streams, and conglomerates can be formed by other agencies than ice. But the biological evidence is unmistakable; cold-blooded reptiles cannot live in icy water; semi-tropical plants, or plants whose habitat is in the temperate zone, cannot ripen their seeds and sow themselves under arctic conditions.... We may examine the whole series of geological horizons, from the earliest Palaeozoic beds down to the so-called Glacial beds, and find, so far as I know, no adequate evidence of discontinuous and alternating climates, no evidence whatever of the existence of periods of intense cold intervening between warm periods, but just the contrary. Not only so, but we shall find that the differentiation of the earth"s climate into tropical and arctic zones is comparatively modern, and that in past ages not only were the climates more uniform, but more evenly distributed over the whole world."
Without attempting to follow through the whole series of formations we may note a few characteristic statements of the text-books. Thus Dana says of the Cambrian:
"There was no frigid zone, and there may have been no excessively torrid zone."
While of the Silurian coral limestones of the Arctic regions he says:
"The formation of thick strata of limestone shows that life like that of the lower lat.i.tudes not only existed there, but flourished in profusion."[69]
Howorth thus quotes Colonel Fielden, the Arctic explorer, regarding the fossil Sclerodermic corals of the Silurian, widely distributed in the Arctic regions:
"These undoubted reef-forming corals of the Silurian epoch were just as much inhabitants of warm water in northern lat.i.tudes at that period as are the Sclerodermata of to-day in the Indo-Pacific and Atlantic oceans.... These corals were forms of life which must have been tropical in habits and requirement."
In fact coral limestones of the Carboniferous system are the nearest known fossiliferous rocks to the North Pole, and from the strike of the beds must underlie the Polar Sea. In the words of Howorth, "Coal strata with similar fossils have occurred all round the Polar basin ... and may be said, therefore, to have occupied a continuous cap around the North Pole."[70]
Again I quote from Howorth regarding the Mesozoic rocks: