Can a fish judge its course by the sun, or by the circulation of the waters of which it is so much a part? Can we talk about a homing instinct, or orienting ability, in connection with it? What are we defining? I don’t think I beg the question by finding it pertinent that civilized human beings have to some extent lost their ability to find their way in the woods, or no longer rise and sleep with the sun, or that they are not aware of the changing tides. Some old directional knowledge may still be innate in us, though we seem to think we have no need of it. Our puzzle, or lack of definition, may lie with ourselves as much as the alewives. In any case, what we try to find out by fact or abstraction is already known to the fish. They are still ahead of us. So much of their motion seems to be a part of the race as a whole, synonymous with its great water world, that it is almost as if they found their way like the wind and tides, elemental forces that we find it hard to evaluate. We try to pin down that which expands immeasurably beyond us. VII Port of Entry With a certain amount of half-determined knowledge behind me, I decided early one morning to follow up the question of how far the brackish waters of the Stony Brook outlet extended into Cape Cod Bay, and so went down to Paine’s Creek. This is the place where the stream, which has been winding through tidal marshes like a small river, ends in a basin where several dories are moored, then takes a last turn and long curve, cutting through low dunes anchored by beach grass that border the sands. I saw a kingfisher rising up over the creek, a green crab shifting along the shelving bank; and on the beach were the remains of a black duck, sodden, bedraggled, the feathers loaded with wet sand, the breastbone sticking up like the white prow of a helmet, flies buzzing over it--the smell of salted carrion around it. The sound of the waters along the creek is constant and musical, following and followed up, broadly roaring, rushing, or slipping lightly, as they rise, pushed back by the incoming tide, or run out low and easy with the ebb. At low tide these creek waters spread their channels and fingered rivulets some three hundred yards straight out over the sands, to a point where they are joined by the waters of Quivett Creek which has an inlet a few hundred yards upshore to the west. Then the one channel finds its way past a fish weir until it is lost in the salt waters coming in over a long bar in the distance. The alewives also swim into the other creek; though not in the numbers that run up Stony Brook, because of less access to spawning grounds beyond.