THE complete story of the breeding of the European eel has now been told by Dr. Johs. Schmidt in a memoir published by the Royal Society (Phil. Trans. B, vol. 211, pp. 179–208, plates 17, 18, April 4, 1922). The publication will become a classic of science, not only because of its literary charm and the results that it sets forth, but as a record of the resolution of a man of science determined to carry his investigation to a satisfactory conclusion.