"The entire subject is discussed with a freshness, as well as an elaboration of detail, that renders his work interesting in a more than usual degree. The facts upon which the Darwinian theory is based are presented in an effective manner, conclusions are ably defended, and the question is treated in more compact and available style than in any other work on the same topic that has yet appeared. It is a valuable addition to the 'International Scientific Series.'"-- _Boston Post._ "The present volume is the thirteenth of the 'International Scientific Series,' and is one of the most interesting of all of them. The subject-matter is handled with a great deal of skill and earnestness, and the courage of the author in avowing his opinions is much to his credit.... This volume certainly merits a careful perusal."--_Hartford Evening Post._ "The volume which Prof. Schmidt has devoted to this theme is a valuable contribution to the Darwinian literature. Philosophical in method, and eminently candid, it shows not only the ground which Darwin had in his researches made, and conclusions reached before him to plant his theory upon, but shows, also, what that theory really is, a point upon which many good people who talk very earnestly about the matter are very imperfectly informed."--_Detroit Free Press._ XIV. The Chemistry of Light and Photography; In its Application to Art, Science, and Industry. _By Dr. HERMANN VOGEL_, Professor in the Royal Industrial Academy of Berlin. WITH 100 ILLUSTRATIONS. 12mo. Price, $2.00. "Out of Photography has sprung a new science--the Chemistry of Light--and, in giving a popular view to the one, Dr. Vogel has presented an analysis of the principles and processes of the other. His treatise is as entertaining as it is instructive, pleasantly combining a history of the progress and practice of photography--from the first rough experiments of Wedgwood and Davy with sensitized paper, in 1802, down to the latest improvements of the art--with technical illustrations of the scientific theories on which the art is based. It is the first attempt in any manual of photography to set forth adequately the just claims of the invention, both from an artistic and a scientific point of view, and it must be conceded that the effort has been ably conducted."--_Chicago Tribune._ XV. Fungi; THEIR NATURE, INFLUENCE, AND USES. _By M. C. COOKE, M. A., LL. D._ Edited by Rev. M. J. BERKELEY, M. A., F. L. S. With 109 Illustrations. Price, $1.50.