The science of criminology has been revolutionized within one generation by the Socialist students of Italy, of whom Ferri is the most prominent living representative. This book is indispensable to any one desiring reliable information on the modern theory of crime and its treatment. 13. +The World's Revolutions.+ By Ernest Untermann. Cloth, 50 cents. A study of the economic causes of the great revolutions of the world's history in the light of the Socialist principle of historical materialism. 14. +The Socialists, Who They Are and What They Seek to Accomplish.+ By John Spargo. Cloth, 50 cents. Scientific yet readable and easy; written in a style that the man in the street will understand and the man in the university will admire. Just the book to start a new reader. 15. +Social and Philosophical Studies.+ By Paul Lafargue. Translated by Charles H. Kerr. In Preparation. This book will contain two studies entirely new to American readers, "Causes of Belief in God," and "The Origin of Abstract Ideas." It will also contain several studies reprinted from the International Socialist Review. Lafargue's brilliant style makes even the most abstract subjects delightful. LIBRARY OF SCIENCE FOR THE WORKERS. Modern International Socialism is directly related to modern science. It is in a sense the evolution theory applied to the facts of society. It, therefore, follows that for a full understanding of socialism some general knowledge of the facts of modern science is necessary. A new series of books has lately appeared in Germany which give in simple and popular form complete proofs of the evolution theory along with a clear account of the latest applications of this theory in the various fields of modern science. We have arranged to translate and publish some of the best of these, along with such original works in the same line as are available. They are uniform in size with the Standard Socialist Series. 1. +The Evolution of Man.+ By Wilhelm Boelsche. Translated by Ernest Untermann. Cloth, 50 cents. "The Evolution of Man" tells in full detail, in a clear, simple style, illustrated by pictures, just how the descent of man can be traced back through monkeys, marsupials, amphibians, fishes, worms and lower forms of life, down to the animals composed each of a single cell. Moreover, it proves that there is no such fixed line as was formerly thought to exist between the organic and the inorganic, but that the same life-force molds the crystal that molds the cell. It is not only simple; it is up-to-date and gives the latest discoveries in science. It is _the_ book on the subject. 2. +Germs of Mind in Plants.+ By R. H. France. Translated by A. M. Simons. Cloth, illustrated, 50 cents.