Produced by Greg Bergquist, JoAnn Greenwood, and the Online Distributed Proofreading Team at http://www.pgdp.net (This file was produced from images generously made available by Biodiversity Heritage Library.) Established by Edward L. Youmans APPLETONS' POPULAR SCIENCE MONTHLY EDITED BY WILLIAM JAY YOUMANS VOL. LIV NOVEMBER, 1898, TO APRIL, 1899 NEW YORK D. APPLETON AND COMPANY 1899 COPYRIGHT, 1899, BY D. APPLETON AND COMPANY. VOL. LIV. ESTABLISHED BY EDWARD L. YOUMANS. NO. 2. APPLETONS' POPULAR SCIENCE MONTHLY. DECEMBER, 1898. _EDITED BY WILLIAM JAY YOUMANS._ CONTENTS. PAGE I. Wheat-growing Capacity of the United States. By E. ATKINSON, 145 II. The Racial Geography of Europe. The Jews. By Prof. WILLIAM Z. RIPLEY. (Illustrated.), 163 III. The Playgrounds of Rural and Suburban Schools. By I. G. OAKLEY, 176 IV. Up the Skeena River. By GEORGE A. DORSEY, Ph. D. (Illus.), 181 V. Light and Vegetation. By Prof. D. T. MACDOUGAL, 193 VI. The Stone Age in Egypt. By J. DE MORGAN, 202 VII. Superstition and Crime. By Prof. E. P. EVANS, 206 VIII. A Geological Romance. By Prof. J. A. UDDEN. (Illustrated.), 222 IX. The Season of the Year. By GRANT ALLEN, 230 X. Brain Weights and Intellectual Capacity. By JOSEPH SIMMS, M. D., 243 XI. Speleology, or Cave Exploration. By M. E. A. MARTEL, 255 XII. Sketch of Charles Henry Hitchcock. (With Portrait.), 260 XIII. Editor's Table: Evolution and Education.--David Ames Wells.--A Borrowed Foundation, 269 XIV. Scientific Literature, 274 XV. Fragments of Science, 282 NEW YORK: D. APPLETON AND COMPANY, 72 FIFTH AVENUE. SINGLE NUMBER, 50 CENTS. YEARLY SUBSCRIPTION, $5.00. COPYRIGHT, 1898, BY D. APPLETON AND COMPANY. Entered at the Post Office at New York, and admitted for transmission through the mails at second-class rates. [Illustration: CHARLES H. HITCHCOCK.] APPLETONS' POPULAR SCIENCE MONTHLY. DECEMBER, 1898. THE WHEAT-GROWING CAPACITY OF THE UNITED STATES. BY EDWARD ATKINSON.