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Man owes his five toes and five fingers to the early amphibians of the sub-carboniferous times. The first tangible evidence of these five toes upon the earth is, to me, very interesting. The earliest record of them that I have heard of is furnished by a slab of shale from Pennsylvania, upon which, while it was yet soft mud, our first five-toed ancestor had left the imprint of his four feet. He was evidently a small, short-legged gentleman with a stride of only about thirteen inches, and he carried a tail instead of a cane. He was probably taking a stroll upon the shores of that vast Mediterranean Sea that occupied all the interior of the continent when he crossed his mud flat. It was raining that morning–how many million years ago?–as we know from the imprint of the raindrops upon the mud. Probably the shower did not cause him to quicken his pace, as amphibians rather like the rain. Just what his immediate forbears were like, or what the forms were that connected him with the fishes, we shall probably never know. Doubtless the great book of the rocky strata somewhere holds the secret, if we are ever lucky enough to open it at the right place. How many other secrets, that evolutionists would like to know, those torn and crumpled leaves hold!

It is something to me to know that it rained that day when our amphibian ancestor ventured out. The weather was beginning to get organized also, and settling down to business. It had got beyond the state of perpetual mist and fog of the earlier ages, and the raindrops were playing their parts. Yet, from all the evidence we have, we infer that the climate was warm and very humid, like that of a greenhouse, and that vegetation, mostly giant ferns and rushes and lycopods, was very rank, but there was no grass, or moss, no deciduous trees, or flowers, or fruit, as we know these things.

A German anatomist says that we have the vestiges of one hundred and eighty organs which have stuck to us from our animal ancestors,–now useless, or often worse than useless, like the vermiform appendix. Eleven of these superannuated and obsolete organs we bring from the fishes, four from amphibians and reptiles. The external ear is a vestige–of no use any more. Our dread of snakes we no doubt inherited from our simian ancestors.

How life refined and humanized as time went on, sobered down and became more meditative, keeping step, no doubt, with the amelioration of the soil out of which all life finally comes. Life’s bank account in the soil was constantly increasing; more and more of the inorganic was wrought up into the organic; the value of every clod underfoot was raised. The riot of gigantic forms ceased, and they became ashes. The giant and uncouth vegetation ceased, and left ashes or coal. The beech, the maple, the oak, the olive, the palm came in. The giant sea serpents disappeared; the horse, the ox, the swine, the dog, the quail, the dove came in. The placental mammals developed. The horse grew in size and beauty. When we first come upon his trail, he is a four-hoof-toed animal no larger than a fox. Later on we find him the size of a sheep with one of his toes gone; still later–many hundred thousand years, no doubt–we find him the size of a donkey, with still fewer toes, and so on till we reach the superb creature we know.

The creative energy seems to have worked in geologic time and in the geologic field just as it works here and now, in yonder vineyard or in yonder marsh,–blindly, experimentally, but persistently and successfully. The winged seeds find their proper soil, because they search in every direction; the climbing vines find their support, because in the same blind way they feel in all directions. Plants and animals and races of men grope their way to new fields, to new powers, to new inventions.