dwindles into nothingness, when compared with the vastness of the interstellar spaces or the size of the larger stars. Whoever conscientiously endeavors to form any idea of the teachings of astronomy and geology, must necessarily feel any prejudice which he had for man as the object and culmination of either the evolutionary or creative power, shrink at a tremendous rate, while over his mentality comes the sense of his diminutiveness, which awakens in him a brotherly feeling for even the primitive single-celled Laurentian Eozoon Canadensis, or the unnucleated monera of the present time. It must have been this same sense-perception in the Hindoos which made them worship and revere life wherever they found it, and which inspired them with so active a sympathy toward all living things.

CHAPTER II
The Length of Time during which Man has Existed

In the preceding chapter, no mention has been made of the length of the Quaternary sub-division of Cenozoic time, and it will now be our aim to briefly review this period and then investigate the evidence which we have as to how much of this time man has been a portion of its fauna.

With the opening of the Quaternary Period, we come to what is undoubtedly the most remarkable era in all geological time. From a climate which had been, heretofore, uniformly, warmly temperate, with but few exceptions, we come to a period known as the Glacial, in which, by a depression in the temperature, all vegetation and animals in high latitudes were killed; viz.: in the central west—almost to the Ohio River; in Europe—to the northern part of Italy—while the addition of vast quantities of ice to the oceans, destroyed all life in them to about the latitude of the northern portion of the Gulf of Mexico. Nor was this period of cold confined to the northern hemisphere, as the southern part of South America and Africa show. Concerning the cause of the Glacial Period, but little is positively known. Of the theories which have been advanced, it seems very plausible that perhaps two more clearly account for the conditions which must have then existed, if we consider them together, than all the rest.

The geological record teaches us that in the so-called Glacial Period, at least two distinct epochs of low temperature, and the consequential accumulation of ice, are to be definitely discerned. Still further back, we see evidence of glacial action in the Permian Strata, and possibly as far back as the Cambrian formations, although these eras of cold are not comparable with the period at the beginning of the Quaternary time. Croll, the Scottish physicist, first called attention to the fact that at certain regular intervals of time, the precession of the equinoxes, and the eccentricity of the earth’s orbit, would so act in conjunction as to render favorable a great many conditions which would certainly all point toward a period of extreme cold. He calculated that the earth was traveling around the sun in an ellipse of maximum eccentricity, and that winter was occurring in the northern hemisphere when the earth was furthest from the sun, for the last time some quarter of a million years ago. About eighty thousand years after this date, the coincidence of the two phenomena reached a maximum effect, and about eighty thousand years later, climatic conditions were again about as we have them to-day. Upon this hypothesis, another period of extreme cold must have existed some one-half million years earlier, as calculations upon the same premises as were used in the last computation will show. It is likewise true that, according to this theory, there must have been at least one other such period further back in geological time, and it is now to be seen whether our records, as shown by the strata, establish these facts.

Prior to the enunciation of this theory by Croll, the famous English geologist, Sir Charles Lyell, from measurements of the strata, had calculated that the last period of glaciation occurred about as Croll stated, and that a period of cold and ice far more intense and extensive occurred some four or five hundred thousand years earlier. Mr. Laing has shown that, in order to make such conditions as must have existed at this time, not only is a low temperature necessary, but a certain amount of land must have an elevation sufficient to give the required initial fall to the ice river, so that it may move over the obstacles in its way, and that the higher such elevations in the Arctic zones, and the greater the humidity of the air when it strikes such elevated polar plateaux, the more augmented will be the probability of glacial activity. The rapidity of the glacier’s movement can have no bearing upon the duration of the glacial period, inasmuch as a certain length of time may have been required for the ice-cap to form and push forward to a certain place, and it may have remained there for an indeterminate period, governed only by the amount of snow deposited upon the original source, and the rapidity of melting at the moraine. In Eastern England, no less than four distinct boulder clays have been found separated by the débris deposited from the moraines of each ice sheet, and a few hundred miles away in France, the record is so certain that we know that the Arctic fauna and flora gave away twice for that of the warmer parts of the Temperate zones.

We are certain that both that portion of Scandinavia and Canada, which were the centers of the great European and American ice-caps, had an elevation greatly in excess of what it is to-day, at the time of the glacial epoch. During the first glaciation, Eastern Canada, or that part south of Hudson’s Bay, was certainly twenty-five hundred feet higher than it is now, and the area covered by ocean formations or marine beds to the southward, show that at the same time these sections were very much lower than they are at the present day. On the other side of the Atlantic Ocean, the elevation in Norway was at least a couple of thousand feet more than at present; while both England and Ireland have risen a considerable amount since this period.

There are other ways by which we may form some estimate of the time which has elapsed since the melting away of the great glaciers, besides that given by Croll. From measurements taken on Table Rock, at Niagara Falls, which we know has receded in post-glacial times from Lewiston to the place which it occupies at present, we are certain that Lyell was not far wrong when he estimated this to have taken at least sixty thousand years. Shaler, on entirely different grounds,—mainly the redistribution of certain angiosperms—has arrived at figures in excess of these. Calculations made upon the canyons of the Columbia, San Joaquin, and Colorado Rivers, all show the estimations previously given to be conservative. Of course, the figures given will apply only to the time which has elapsed since the melting of the American ice-cap, as we have no means of knowing that the American and European glaciers acted at all in unison in their retreat to the northward. The manner in which we can get some idea of the length of time required to account for the enormous quantity of work done in the Champlain period, is by taking into account the deposits which lie in almost all of the great river valleys which were covered by the glaciers, or whose watersheds were made into lakes by the subsidence of the land to the north, and the rapid melting of that portion of the ice-cap which contained stones,