He peered through the lens and adjusted the focus until the blood cells began to materialize, red and blue and shades in between, different shapes and sizes, representing distinct lineages and stages of development. In all these years, it never failed to amaze him, this magnificent dappled sea of bone marrow, ever regenerating and replenishing itself in an ongoing cycle that made life possible—red cells that carried oxygen to the tissues, white cells that fought off infection, and platelets that made the blood clot. Magnificent.
