It is impossible in this brief note to give any adequate summary of the volume or of the position of the author on questions of general interest; the subjects of the chapters, however, may serve to give some idea as to the scope of the work. After an introduction which gives a brief historical sketch of the cell theory and its relation to the evolution theory, there are taken up in successive chapters a general sketch of cell structure, cell division, the germ cells, fertilization of the ovum, the formation of the germ cells and the halving of their nuclei preparatory to fertilization, cell organs and their relations to each other and to the life of the cell, cell chemistry and cell physiology, cell division in its relation to the development of the egg, and finally, some theories of inheritance and development. In addition, there is appended an excellent glossary and a list of all the most important literature on the subject up to the current year. While the work is undoubtedly intended as a reference book for investigators and advanced students in biology, being marked by the thoroughness of treatment of an original communication, it is yet so well written and so copiously illustrated as to make it not only intelligible but also intensely interesting to the general reader. _EDUCATION._ The most important recent book on education is undoubtedly ‘Education in the United States,’ a book prepared in connection with the educational exhibit of this country at the Paris Exposition. It consists of a series of monographs which cover all the important phases of educational endeavor in the United States. The two volumes include nearly a thousand pages, almost all of which present definite and reliable facts. Only rarely is there any indulgence in expressions of private opinion, and still more rarely is such opinion questionable. The editor is justified in his statement that the book is ‘a cross-section view of education in the United States in 1900.’ It will be of great value to the student of American institutions or of education in general, and should be of interest to any citizen who desires to be well informed about his country. The quality of the monographs will be evident from the list of the author’s names. For instance, those writing on higher education are Prof. A. F. West, of Princeton; Prof. E. D. Perry, of Columbia; President Thomas, of Bryn Mawr; Director Parsons, of the University of the State of New York; President Mendenhall, of the Worcester Polytechnic Institute, and Prof. H. B. Adams, of Johns Hopkins. THE PROGRESS OF SCIENCE.