Hydra and the Birth of Experimental Biology 1744. Abraham Trembley's Memoirs Concerning the Polyps. Book I: Some Reflections on Abraham Trembley and His Memoires. Book II: A Translation from the French of Memoires, pour servir a L'histoire d' un genre de polypes d'eau douce, a bras en forme de cornes.Sylvia G. Lenhoff , Howard M. Lenhoff