sand have a part. Though so humble now, they once formed the rocky barriers of the shore. They stood as do the rocks of to-day, defiant and seemingly everlasting, but the fury of the sea, which knows no invincible adversary, has laid them low. Every coast-line shows the destructive effects of the sea, for the bays and coves, the caves at the bases of the cliffs, the buttresses, stocks, needles, and skerries, are the work of the waves. And this work is constantly going on.

The story of the sands is not only one of the conflict of the sea and rocks; it is also a story of the winds. It is the winds that have rescued them from the waves and driven them about, sifting and assorting them, arranging them in graceful forms, and often heaping them up into dunes which, until fastened by vegetation, are themselves ever moved onward by the same force, sometimes burying fertile lands, trees, and even houses in their march. The sands, moreover, are in turn themselves destructive agents, to whose power the many fragments which strew the beach and dunes bear ample witness. The knotty sticks so commonly seen on the beach are often the hearts of oak- or cedar-trees from which the tiny crystals of sand have slowly cut away their less solid outer growth. Everything, in fact, upon the sands is "beach-worn," even to the window-glass of life-saving stations, which is frequently so ground that it loses its transparency in a single storm.

The beach is also a vast sarcophagus holding myriads of the dead. "If ghosts be ever laid, here lie ghosts of creatures innumerable, vexing the mind in the attempt to conceive them." And there are certain sands which may be said to sing their requiem, the so-called musical sands, like the "Singing Beach" at Manchester-by-the-Sea, which emit sounds when struck or otherwise disturbed. On some beaches these sounds resemble rumbling, on others hooting; sometimes they are bell-like and even rhythmical. The cause of this sonorous character is not definitely known, but it is possibly due to films of compressed gases which separate each grain as with a cushion, and the breaking of which [pg003] causes, in the aggregate, considerable vibrations. Such sands are not uncommon, having been recorded in many places, and they exist probably in many others where they have escaped observation. They may be looked for above the water-line, where the sand is dry and clean.

We have to do, however, in this volume, not with the history of the past, nor with the action of physical forces, but with the life of the present, and to find this, in its abundance, one must go down near the margin of the water, where the sands are wet. There is no solitude here; the place is teeming with living things. As each wave retreats, little bubbles of air are plentiful in its wake. Underneath the sand, where each bubble rose, lives some creature, usually a mollusk, perhaps the razor-shell Solen ensis. By the jet of water which spurts out of the sand, the common clam Mya arenaria reveals the secret of its abiding-place. A curious groove or furrow here and there leads to a spot where Polynices heros has gone below; and the many shells scattered about, pierced with circular holes, tell how Polynices and Nassa made their breakfast and their dinner. Only the lifting of a shovelful of sand at the water's edge is needed to disclose the populous community of mollusks, worms, and crustaceans living at our feet, just out of sight.

Even the tracks and traces of these little beings are full of information. What may be read in the track of a bird on the sand is thus described by a noted ornithologist:

Following the key further, he draws more conclusions. The tracks are not in pairs, so the bird does not belong to the perchers; therefore it must be a wader or a swimmer. There are no web-marks to indicate the latter; hence it is a three-toed walking or wading bird.