Life has particular, even narrow, definitions, like those distinct levels of the beach to which different species are adapted. Plants and animals that live in the sand, on the cliff tops, or on the ocean floor beyond the surf, have been responding in the same way for millions of years. All this is well known to natural science. In fact, to make too many ignorant and loose generalities about it is probably an offense to the circumstances; but together with precise conditions goes a vast scope, a space, and a speed like the overworld racing of the ocean tide. The beach and its sands, the waves that cut them away or build them up, its long roaming, and its give and take with respect to the sea, involves a balance that cannot be separated from the globe itself, with an age and a future where time is nearly lost. Seaweed, crabs, shells, fish, or birds are all ancient, exact, and well defined. (It may take hundreds of thousands of years to change the shape of a head or a claw.) They are also part of a motion which is not changed into a machine by being called perpetual. In any case, each form, through the countless passages of light and dark, was endowed with a joyful resistance to finality. Within the shifting landscape of the sea beach all action, each affinity, and each response, seems controlled and at the same time free and exemplary. The elements agree in making the junctures of light unparalleled. Here are the eternal crossways of tides, wind, and sunlight, full of an indefinite potentiality that comes more clear to human eyes because of their lack of obstruction. I think of one area in particular which combines this wide range of view with conflict and meeting more than most. Where the great beach has its last break at Chatham, before the long sandy island, or sandspit, of Monomoy, the tide races through and behind it into Chatham Harbor, and toward the west it flows between Morris Island and Monomoy into Nantucket Sound. There is so much intermingling of currents and tides, so many effects of sky light and clouds and direct sunlight spreading over this area, together with sea smells and varying winds, as to give it an effect of constant remaking and realliance. From the Morris Island shore the surf shows up in the distance above the long low barrier of the Outer Beach like a mirage of waves and when the north wind flings back spray on their crests they might be great dolphins plunging forward through the sea. The cloud masses shift and change, tall in the spring or autumn sky, over sand and long stretches of green and blue water.