Except for the promontories north and south, and the bold front of the Berkeley Hills opposing the Gate, the inland borders of the bay are flat tide-lands and sea-smelling lagunas. Stilts, avocets, herons, all the waders that haunt this coast or visit it in their seasonal flights, may be seen stalking the shallows for minnows, or where the marsh grass reddens, poised like some strange tide-land blossom, lifted on two slender stems. Low over them any clear day may be seen the grey old marsh hawk sailing, or the "duck hawk," the peregrine of falconry, following fiercely in the wake of the migrating hordes of water-fowl. All about Alviso the guttural cry of the black-crowned night-heron sounds eerily above the marshes, along with the peculiar "pumping" love-song of the bittern. For some reason the air of the marshes is friendly to the mistletoe infesting the oaks and sycamores which stand back from the tide-line; but the marshes themselves are treeless. They have their own sorts of growth, cane and cat-tails and tule, goosefoot, samphire, and the tasselled sedges. This samphire of Shakespeare, _l'herbe de Saint Pierre_ of the Normandy Marshes, is the glory of the Franciscan tide-lands; miles of it, barely above the level of the slow-moving water, spread a magic carpet of blending crimsons, purples, and bronzes. Under the creeping mists and subject to the changes of the water, beaten to gold and copper under the sun, it redeems the flat lines of the landscape with a touch of Oriental splendour.