Prof. C. A. YOUNG, Ph. D. (of Dartmouth College). The Sun.
Prof. OGDEN N. ROOD (Columbia College, N. Y.). Modern Chromatics and its Relations to Art and Industry.
Dr. EUGENE LOMMEL (University of Erlangen). The Nature of Light.
Prof. J. ROSENTHAL. General Physiology of Muscles and Nerves.
Prof. JAMES D. DANA, M. A., LL. D. On Cephalization; or, Head-characters in the Gradation and Progress of Life.
Prof. S. W. JOHNSON, M. A. On the Nutrition of Plants.
Prof. AUSTIN FLINT, Jr., M. D. The Nervous System, and its Relation to the Bodily Functions.
Prof. BERNSTEIN (University of Halle). The Five Senses of Man.
Prof. FERDINAND COHN (Breslau University). Thallophytes (Algæ, Lichens, Fungi).
Prof. HERMANN (University of Zurich). Respiration.