John Hay celebrates the living tides of our planet — the pulse and seethe of ocean, the migratory floods of birds and fish. The subtle cadences of his prose capture these rhythms and also evoke, better than any writing I know, the mysterious kinship at the heart of evolution. The present collection, with its fine introduction by Christopher Merrill, succeeds wonderfully in conveying the faithfulness, the scientific venturesomeness, and the purity of style that have marked John Hay’s work over a career spanning half a century.