XXVI. STUDENTS’ TEXT-BOOK OF COLOR, OR, MODERN CHROMATICS. With Applications to Art and Industry. By Professor OGDEN N. ROOD, Columbia College. New edition. With 130 Illustrations. $2.00. XXVII. THE HUMAN SPECIES. By Professor A. DE QUATREFAGES, Membre de l’Institut. $2.00. XXVIII. THE CRAYFISH: an Introduction to the Study of Zoölogy. By T. H. HUXLEY, F. R. S. With 82 Illustrations. $1.75. XXIX. THE ATOMIC THEORY. By Professor A. WURTZ. Translated by E. CLEMINSHAW, F. C. S. $1.50. XXX. ANIMAL LIFE AS AFFECTED BY THE NATURAL CONDITIONS OF EXISTENCE. By KARL SEMPER. With Two Maps and 106 Woodcuts. $2.00. XXXI. SIGHT: An Exposition of the Principles of Monocular and Binocular Vision. By JOSEPH LE CONTE, LL.D. With 132 Illustrations. $1.50. XXXII. GENERAL PHYSIOLOGY OF MUSCLES AND NERVES. By Professor J. ROSENTHAL. With 75 Illustrations. $1.50. XXXIII. ILLUSIONS: A Psychological Study. By JAMES SULLY. $1.50. XXXIV. THE SUN. By C. A. YOUNG, Professor of Astronomy in the College of New Jersey. With numerous Illustrations. $2.00. XXXV. VOLCANOES: What they Are and what they Teach. By JOHN W. JUDD, F. R. S., Professor of Geology in the Royal School of Mines. With 96 Illustrations. $2.00. XXXVI. SUICIDE: An Essay in Comparative Moral Statistics. By HENRY MORSELLI, M. D., Professor of Psychological Medicine, Royal University, Turin. $1.75. XXXVII. THE FORMATION OF VEGETABLE MOULD, THROUGH THE ACTION OF WORMS. With Observations on their Habits. By CHARLES DARWIN, LL.D., F. R. S., author of “On the Origin of Species,” etc., etc. With Illustrations. $1.50. XXXVIII. THE CONCEPTS AND THEORIES OF MODERN PHYSICS. By J. B. STALLO. $1.75. XXXIX. THE BRAIN AND ITS FUNCTIONS. By J. LUYS. $1.50. XL. MYTH AND SCIENCE. An Essay. By TITO VIGNOLI. $1.50. XLI. DISEASES OF MEMORY: An Essay in the Positive Psychology. By TH. RIBOT, author of “Heredity.” From the French, by WILLIAM HUNTINGTON SMITH. $1.50. XLII. ANTS, BEES, AND WASPS. A Record of Observations on the Habits of the Social Hymenoptera. By Sir JOHN LUBBOOK, Bart., F. R. S., D. C. L., LL. D., etc. New York: D. APPLETON & CO., 1, 3, & 5 Bond Street. THOMAS H. HUXLEY’S WORKS. =Science and Culture, and other Essays.= 12mo. Cloth, price, $1.50. =The Crayfish=: An Introduction to the Study of Zoölogy. With 82 Illustrations. (“International Scientific Series.”) 12mo. Cloth, $1.75. =Science Primers: Introductory.= 18mo. Flexible Cloth, 45 cents. =Man’s Place in Nature.= 12mo. Cloth, $1.25. =On the Origin of Species.= 12mo. Cloth, $1.00.