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 AUGUST NUMBER The Mid-summer Bird Life of Illinois: A Statistical Study. Professor S. A. FORBES. The Life Cycle of Paramecium when subjected to a Varied Environment. DR. LORANDE LOSS WOOD RUFF. Placobdella Pediculata n. sp. ERNEST E. HEMINWAY. Marine Laboratories and our Atlantic Coast. DR. ALPRED G. MAYER, Biometry as a Method in Taxonomy. CHARLES LINCOLN EDWARDS. Professor Shorter Articles and Correspondence: The Genus Ptiloerinus, AUSTIN HOBART CLARK. A New Rhinoceros from the Lower Miocene of Nebraska, HAROLD JAMES COOK. Notes and Literature: Plant Cytology-Some Recent Research on the Cilia-forming Organ of Plant Cells, DR. BRADLEY M. DAVIS. Ornithology-Riddle on the Genesis of Fault-bars and the Cause of Alternation of Light and Dark Bars in Feathers, J. A. A. Herpetology-Ruthven's Variations and Genetic Relationships of the Garter-snakes, J. A. A. Lepidoptera -Hybrid Lepidoptera, Professor T.D. A. COCKERELL Single Number 35 Cents ALLEN. The Origin of the Lateral Eyes of Vertebrates Professor G. H. PARKER. Notes and Literature: Heredity-Spurious Allelomorphism, Results of Some Recent Investiga tions, W. J. SPILLMAN. Human AnatomyPryor on Sexual and Family Variation in Centers of Ossification, C. R. B Plant Cytology-Cytological Studies on 8aproleguia and Vaucheria. DR. BRADLEY M. DAVIS. Holothurians-Holothurioidea, Professor CHARLES L. EDWARDS. Enteropneusta-Recent Literature on the Enteropneusta, Professor W. E. RITTER. Vertebrate Paleontology-Case on Pelycosauria of North America; Barnum Brown on the Conrad Fissure and on the Ankylosauridae, Professor 8. W. WILLISTON. Parasitology-The Evolution of Parasitism; Trypanosomes, H. B. W. CONTENTS OF THE NOVEMBER NUMBER Further Studies on the Activities of Araneads. Professor THOS. H. MONTGOMERY, Jr. Notes on the Daily Life and Food of Cambarus Bartonius Bartoni. FLOYD E. CHIDESTER, Some Points in the Ecology of Recent Crinoids, AUSTIN HOBART CLARK. Shorter Articles and Correspondence: Evolution without Isolation, O. F. Cook. A Note on the Silverside, JOHN TREADWELL NICHOLS. Notes and Literature: Botany-The Origin of a Land Flora, Professor DOUGLASS HOUGHTON CAMPBELL. Plant Cytology-Apogamy in the Ferns, Dr. BRADLEY M. DAVIS. Experimental Evolution-Regeneration in Lumbriculus, SERGIUS MORGULIS. The Budgett Memorial Volume-John Samuel Budgett, President DAVID STARR JORDAN. Animal Behavior-Mind in Animals, Professor H. S. JENNINGS, CONTENTS OF THE JANUARY NUMBER Juvenile Kelps and the Recapitulation Theory. Professor ROBERT F. GRIGGS, The Larva and Spat of the Canadian Oyster, Dr. J. STAFFORD. Shorter Articles and Correspondence: Some Notes on the Traditions of the Natives of Northeastern Siberia about the Mammoth, WALDEMAR JOCHELSON. Age of Trotting Horse Sires, F. R. MARSHALL The Occurrence of Batrachoceps attenuatus and Autodaz lugubris in Southern California, WILLIAM A. HILTON. Notes and Literature: Experimental Evolution-The Effect of the Environment upon Animals, Dr. FRANK E LUTZ. Experimental Zoology-The Influence of the Size of the Egg and Temperature on the Growth of the Frog, SERGIUS MORGULIS. Parasilology-Cestodes of Birds, Professor HENRY B. WARD. 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. Practical Exercises in Microscopical Methods By MICHAEL F. GUYER 250 pages, 8vo, cloth; net $1.75, postpaid $1.88 ΤΗ HE title of this book will explain its scope. It is intended as a laboratory manual for textbook use. Its aim is to introduce the student to the technique of microscopic anatomy and embryology, emphasizing details of procedure rather than descriptions of reagents or apparatus. Sufficient account of the theoretical side of microscopy is given to enable the student to get satisfactory results from his microscope. The directions are simple, explicit. and complete.-American Journal of Clinical Medicine. The medical student will find it very useful as a guide to microscopic work. -Journal of the American Medical Association. This is one of the cleanest works on microscopical technique we have ever seen, and is especially suitable for the beginner. It is full of points, tricks of technique not mentioned in other works, and is one that every student and physician should have.-Medical Century. This valuable book is strong through its rigid exclusion of the trite and the conflicting. It is lucid and helpful, because a man long practiced in practical work has given what he believes the most expeditious and reliable method of obtaining a definite and comprehensive result.-Medical Notes and Queries. A concise, eminently practical, and well-classified treatment.-Science. The expositions of the methods recommended are admirably clear.Nature. One of the best and most practical works upon microscopic technique with which we are acquainted.American Naturalist. As a textbook it can hardly be improved. The research worker will find in this book just the information he frequently needs in preparing material with which he is not familiar. -School Review. It does present in very clear form a judicions selection of methods, including an excellent untechnical account of the microscope and its optical principles, adequate for the undergraduate course in histology.-Journal of Comparative Neurology and Psychology. Address Dept. 62 The University of Chicago Press CHICAGO NEW YORK 88. (tended for publication and books, etc., intended for review should be Litwaediture; THE AMERICAN NATURALIST, Garrison-an-Houson, New York. tores vontaining research work bearing on the problems of organic evalubengewindy welcome, and will be given preference in publication. pamecen reprints of contributions are supplied to authors free of charge. povas and advertisements should be sent to the public. The THE SCIENCE PRESS ·ORK. Sub-Station 34 Garrison, N. Y. THE AMERICAN NATURALIST VOL. XLIII March, 1909 No. 507 INVITATION PAPERS AT THE BALTIMORE MEETING OF THE BOTANICAL SOCIETY OF AMERICA Ar the recent Baltimore meeting of the Botanical Society of America, three series of special papers were read by members who were specially requested by the council of the society to prepare them for the occasion. The first set of papers dealt with certain phases of recent advance in our knowledge of vascular anatomy in plants. These papers, read on December 29, were by J. M. Coulter and E. C. Jeffrey. 99 on The papers of the second series were read at a symposium on "Present Problems in Plant Ecology, Wednesday, December 30. The participants were H. C. Cowles, B. E. Livingston, C. H. Shaw, V. M. Spalding and E. N. Transeau. The papers of the third series were read at the Darwin Memorial Session, held on Thursday, December, 31. These addresses gave estimates of Darwin's work in three fields of botanical investigation. The participants were Wm. Trelease, F. E. Clements and H. M. Richards. In accordance with the instructions of the society, all of the above mentioned papers are here published in full. DUNCAN S. JOHNSON, OFFICE OF THE SECRETARY, Secretary. BALTIMORE, MD., February 1, 1909. DARWIN MEMORIAL SESSION In response to a letter announcing the plans for the Darwin Memorial Session, and suggesting that some |