I am not entitled to an opinion, but have doubts, nevertheless, of the wisdom of considering every slightly different form as made by a different creature. I have given my reasons, and will only add another instance, one of greater significance than all as bearing upon the question. I startled a slumbering jumping-mouse last summer and it bounded across the smooth sand bared by the outgoing tide. Its track then was one made by its body rather than the extremities, and a curious dent in the river-shore’s smooth surface it was; but before taking again to the woods it walked in its peculiar way, and the little footprints were quite distinct and unmistakably those of a small mammal. Had the two sets of markings been preserved in a slab of sandstone, no ichnologist would have recognized the truth, but probably would have said, “Here is a case where some leaping creature has overtaken a small rodent and devoured it.” Difficult as fossil footprints may be to decipher, they call up with wonderful distinctness the long ago of other geologic ages. It is hard to realize that the stone of which our houses are built once formed the tide-washed shore of a primeval river or the bed of a lake or ocean gone long before man came upon the scene. But the footprints of to-day concern me more. Looking over the side of the boat, I saw several mussels moving slowly along and making a deep, crooked groove in the ripple-marked sand, “streaking the ground with sinuous trace,” as Milton puts it; and the school of blunt-headed minnows made little dents in the sand wherever the water was shallow, when they turned suddenly and darted off-shore. This sand seemed very unstable, and a little agitation of the water caused many a mark to be wiped out; and yet we find great slabs of ripple-marked and foot-marked sandstone. I picked up such a piece not long ago on which were rain-drop marks. This is the story of a million years ago; but who ever found Indian moccasin-marks not two centuries old? The footprints that could tell us many a wonderful story are all gone and the tale of a rain-drop remains. This is a bit aggravating. Here where we have pitched our camp, or very near it, was a Swedish village in 1650 and later, and for two days I have been hunting for evidence of the fact,—some bit of broken crockery, rusty nail, glass, pewter spoon, anything,—but in vain. History records the village, and correctly, without a doubt, but there are no footprints here, nor other trace to show that a white man ever saw the place until our tent was pitched upon the beach.