The dance of a struggling Sulfur mayfly drifted past my waders as I watched the display in anticipation. To the unaccustomed eye one would think it was merely a bug struggling in its death throes, but to the trained eye it was the emergence of life. The diminutive mayfly's wings were bent and wrinkled at first, yet beginning to unfold like the canvas of an age-old clipper ship catching its first wind as it left the Philadelphia harbor. Life's metamorphosis was beginning amid the humidity of a 90degree July day that was slowly waning. An ecosystem born of the rich 58 degree limestone water was providing the hatch pursued by so many fly fishermen like myself.