V
One would fain arrive at some concrete belief or image of his line of descent in geologic time as he does in the historic period. But how hard it is to do so! Can we form any mental picture of the actual animal forms that the manward impulse has traveled through? With all the light that palaeontology throws upon the animal life of the past, can we see where amid the revel of these bizarre forms our ancestor hid himself? Can we see him as a reptile in the slime of the jungle or in the waters of the Mesozoic world? What was he like or what akin to? What mark or sign was there upon him at that time of the future that was before him? Can we see him as a fish in the old Devonian seas or lakes? Was he a big fish or a little fish? The primitive fishes were mostly of the shark kind. Is there any connection between that fact and the human sharks of to-day? Much less can one picture to one’s self what his ancestor was like in the age of the invertebrates, amid the trilobites, etc., of the earlier Palaeozoic seas. But we must go back even earlier than that, back to unicellular life and to original protoplasm, and finally back to fiery nebulous matter. What can we make of it all by way of concrete conception of what actually took place—of the visible, eating, warring, breeding animal forms in whose safekeeping our heritage lay? Nothing. We are not merely at sea, we are in abysmal depths, and the darkness is so thick we can cut it.
We meet the same difficulty when we try to figure to ourselves the line of descent of any of the animal forms of to-day. How did they escape the world-wild catastrophe of earlier geologic times? Or did the creative impulse bank upon life as a whole and never become bankrupt, no matter what special lines or forms failed?
The first appearance of the primates is in Eocene times and the anthropoid apes in the Miocene, probably five millions of years ago. The form which may have been in our line of descent, the Dryopithecus, later appears to have become extinct. Did our fate hang upon the success of any of these forms? The monkeys and anthropoid apes appeared at the same time in different countries. Nature seems to have been making preliminary studies of man in these various forms, but when and where she hit upon the form that she perfected in man, who knows?