Tortugas Laboratory of the Carnegie Institution, WILLIAM E. RITTER, 693 Traditions in Northeastern Siberia about the Mammoth, WALDEMAR JOCHELSON, 48 TRANSEAU, EDGAR, Climatic Factors Trotting Horse Sires, Age of, F. R. Tutt, J. W., Blue Butterflies of the Genus Celastrina, T. D. A. CockERELL, 114 Variation, Categories of, S. J. HOLMES, 257; and Heredity in the Simplest Organisms, H. S. JENNINGS, 321; in the Number of Seeds per Pod in the Broom, J. ARTHUR HARRIS, 350 Vascular Anatomy and the Repro ductive Structures, JOHN M. VERRILL, A. E., Development of WARD, HENRY B., The Cestodes of Birds, 63; The Sleeping Sickness Bureau, 124; Parasitology, 567 WATSON, J. B., Benavior of Noddy and Sooty Terns, 700 Whitney, D. D., Development and Sex, W. J. SPILLMAN, 444 Williston on the Lysorophidæ, 116; on the Cotylosauria, 121; on the Oldest Known Reptile, ROY L. MOODIE, 122 Wilson, E. B., on Chromosomes and Hereditary Characters, W. J. SPILLMAN, 24v WRIGHT, ALBERT H., and ARTHUR ALLEN, Breeding Habits. of blystoma punctatum, 687 A Monthly Journal, established in 1867, Devoted to the Advancement of the Biological Sciences with Special Reference to the Factors of Organic Evolution and Heredity CONTENTS OF THE OCTOBER NUMBER The Non-muscular Articulations of Crinoids. AUSTIN HOBART CLARK. On Some Dinichthyid Armor Plates from the Marcellus Shale. BURNETT SMITH. Are Species Realities or Concepts only. Professor J. H. POWERS. Shorter Articles and Discussion: A Light Weight, Port able Outfit for the Study and Transportation of Ants. EDITH N. BUCKINGHAM, Comparison of Canolestes with Polyprotodonta and Diprotodonts. PAULINE H. DEDERER. Notes and Literature: Comparative Psycholoy - Bohn's "The Birth of Intelligence": Professor H. S. JENNINGS. Mammalogy-Osgood's Revision of the Mice of the Genus Peromyscus, Dr. J. A. ALLEN, LEO ERRARA, Professor CHARLES E. BESSEY. CONTENTS OF THE NOVEMBER NUMBER The American Toad (Bufo lentiginosus americanus LeConte). NEWTON MILLER, Notes on the Behavior of the Domestic Fowl. PHILIP B. HADLEY. Vitality of Pine Seeds and the Delayed Opening of Cones. Professor W. C. COKER. The Affinities of the Echinoidea. AUSTIN HOBART CLARK. The Early Breeding Habits of Amblystoma punctatum. Notes and Literature: Marine Biology-Papers from the Tortugas Laboratory, Professor WILLIAM E. RITTER. Experimental Evolution - Inheritance of Color in Pigeons, B. B. HORTON. Single Number 35 Cents Yearly Subscription, $4.00 The NATURALIST will be sent to new subscribers for four months for One Dollar THE SCIENCE PRESS Garrison, N. Y. Sub-Station 84: NEW YORK Lancaster, Pa. By IRVING HARDESTY 196 pages, 8vo, cloth; net $1.75, postpaid $1.87 NTENDED to serve as an introduction and laboratory guide to the study of the architecture of the nervous system, containing a succinct account of methods which have stood the test of practical application. Laboratory Outlines for the Study of the Embryology of the Chick and the Pig WILL By FRANK R. LILLIE 60 pages, 12mo, paper; net 25 cents, postpaid 27 cents ILL be found a valuable contribution toward the establishment of a standard of embryological work for students generally, and for others desiring a con venient guide to the order of study of this subject. A Quantitative Classification of Igneous Rocks Based on Chemical and Mineral Characters, with a Systematic Nomenclature 286 pages, 8vo, cloth; net $1.75, postpaid $1.91 N entirely new system for the classification and nomenclature of igneous rocks according to chemico-mineralogical principles, accompanied by a complete original nomenclature adapted to the system. Of value to all geologists and petrologists. The Role of Diffusion and Osmotic Pressure in Plants By BURTON EDWARD LIVINGSTON THE 160 pages, 8vo, cloth; net $1.50, postpaid $1.62 HE important part played by the phenomena connected with diffusion and osmotic pressure in the life-process has here for the first time found full and adequate treatment. Address Dept. 62 THE UNIVERSITY OF CHICAGO PRESS CHICAGO AND NEW YORK |