In the brief review which we have just given, of what can be conservatively considered the minimum limits of geological time, we have taken into account generally only periods of activity, and in but a few cases has any estimation been hazarded as to the proportion which this was of the whole time consumed in bringing about the changes which the fossils show so clearly to have taken place during the various epochs. But one thing should be kept clearly in mind, and that is, that no matter how long geological time may seem, it is but an infinitely small fraction of the period which must have elapsed since the world came into existence, as this globe had to cool down to below the boiling point of water before any geological records could be made. When thought of in this way, the Laurentian period becomes as but yesterday, and even man's dwelling place, which seems relatively so large, 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.