2. Despite the necessity for treating various sciences, the book is remarkable for its continuity of thought. The interrelation of scientific facts is constantly and clearly pointed out. 3. The treatment is clear-cut, brisk, and thorough, the material well chosen and up to date, while the general workmanship of the book renders it attractive and serviceable. 4. There are over 90 laboratory exercises in the book, a number of them entirely new, and all of them illustrative of the text. 5. Reference reading is encouraged, and lists of carefully selected standard reference books are suggested. Those teachers, however, who do not care to take up detailed work of this sort may give a satisfactory course by using in connection with the book United States Government bulletins alone, to which definite reference is made in the lists of reference readings throughout the book. TEACHERS call the book “thorough,” “practical,” “comprehensive,” “clear,” “satisfactory,” “a great aid to the science teacher.” Mr. N. P. Lawson of Taunton, Washington, writes: “I have examined Rowell’s ‘Introduction to General Science’ quite carefully. It wears. The more I use it the better I like it. There is room left for the teacher. He doesn’t have to crowd himself in. This book can hardly fail to inoculate any one with the bulletin habit, in which I am a firm believer. In its encouragement of wide reading and first-hand acquaintance with books through the excellent references given, this compact little volume is an education in itself. If I were with your company I should wish to push this book. I believe in it.” * * * * * The Laws of Heredity BY G. ARCHDALL REID, M.B., F.R.S.E. With a Diagrammatic Representation BY HERBERT HALL TURNER, Savilian Professor of Astronomy, Oxford _Cloth, 8vo, xi + 548 pages, $5.50_ _by mail, $5.04_ The question of heredity is one of vital concern to every living being, and any light thrown on the subject by scientific investigations and experiments is of momentous interest to the human race. It is therefore of the utmost importance that every one should have some knowledge of the theories advanced by those who believe in the immutability of the laws of heredity, and also how far these have been proven modifiable by environment and education. The present volume is a discussion of the entire subject, covering a much wider area than the author’s “The Principles of Heredity,” and presenting the facts and arguments in a scholarly and yet clear and non-technical manner; the aim being to make it comprehensible to the general reader, as well as to the scientific investigator. * * * * * The First Principles of Heredity BY S. HERBERT