"It 'goes without saying' what precious freight was carried by Huxley's letters.... These two delightful volumes."--_London Chronicle_. "Huxley's life was so full, so active, so many-sided, in touch with such a number of interesting people, that this work appeals to all sorts and conditions of men.... An admirably written biography."--_London Standard_. "His letters are a self-revelation of the man, his work, his ambitions, his trials, his views of religion, his philosophy, his public activity and domestic happiness.... Whoso reads these volumes will feel that he knows better a man worth knowing, and the number who will read them will be great."--_London Telegraph_. "Huxley's career makes a wonderful story."--_London Mail_. "Mr. Leonard Huxley has given the world many extremely valuable and interesting letters, all characteristic, and he has connected them by a well-written consecutive narrative which is sufficient to weave them together."--_London News_. D. APPLETON AND COMPANY, NEW YORK. * * * * * RECENT BOOKS BY DISTINGUISHED SPECIALISTS. THE COMPARATIVE PHYSIOLOGY AND MORPHOLOGY OF ANIMALS. By Prof. JOSEPH LE CONTE. Illustrated. 12mo. Cloth, $2.00. EVOLUTION BY ATROPHY. By JEAN DEMOOR, JEAN MASSART, and ÉMILE VANDERVELDE. A new volume in the International Scientific Series. 12mo, Cloth, $1.50. FOOT-NOTES TO EVOLUTION. A Series of Popular Addresses on the Evolution of Life. By DAVID STARR JORDAN, Ph.D., President of Leland Stanford Junior University. 12mo. Cloth, $1.50. OUTLINES OF THE EARTH'S HISTORY. A Popular Study in Physiography. By Prof. N.S. SHALER, of Harvard University. Illustrated. 12mo. Cloth, $1.50. STUDIES OF GOOD AND EVIL. By JOSIAH ROYCE, Professor of the History of Philosophy in Harvard University. 12mo. Cloth, $1.50. EVOLUTION ETHICS AND ANIMAL PSYCHOLOGY. By E.P. EVANS, Author of "Animal Symbolism in Ecclesiastical Architecture," etc. 12mo. Cloth, $1.75. WAGES AND CAPITAL. An Examination of the Wages Fund Doctrine. By F.W. TAUSSIG, Professor of Political Economy in Harvard University, Author of "Tariff History of the United State" and "The Silver Situation in the United States." 12mo. Cloth, $1.50. WHAT IS ELECTRICITY? By Prof. JOHN TROWBRIDGE, of Harvard University. 12mo. Cloth, $1.50. THE PSYCHOLOGY OF SUGGESTION. A Research into the Subconscious Nature of Man and Society. By BORIS SIDIS, M.A., Ph.D., Associate in Psychology at the Pathological Institute of the New York State Hospitals. With an Introduction by Prof. William James, of Harvard University. Illustrated. 12mo. Cloth, $1.75. D. APPLETON AND COMPANY, NEW YORK * * * * * SPENCER'S SYNTHETIC PHILOSOPHY, 12mo, cloth, $2.00 per volume. _NEW EDITION OF_ First Principles.