door in the face of inductive science. It is time to be undeceived in this matter. LA JOLLA, CALIF., Wm. E. RITTER. EXPERIMENTAL ZOOLOGY Inheritance of Color in Pigeons. The breeding experiments of pigeons, described by R. Staples-Brown in the Proceedings of the Zoological Society of London for 1908, pages 67-104, are of interest because he repeated certain experiments by which Darwin obtained a reversionary type resembling Columba livia. Darwin concluded that domesticated pigeons sprang therefore from the wild rock pigeon. The varieties of pigeons used by Staples-Brown were with one exception identical with those used by Darwin and the experiments were planned on similar lines. Darwin's experiment, it will be recalled, was as follows:1 A black Barb was crossed with a white Fantail and a black Barb with a red Spot (white bird with tail and tail coverts red having a red spot on the forehead). Upon mating hybrids produced by these two crosses Darwin obtained a pigeon identical with Columba livia, excepting that "the head was tinted with a shade of red, evidently derived from the Spot, and was a paler blue than in the rock pigeon." Staples-Brown substituted a black and white Nun for Darwin's red Spot which was not readily obtainable. A Nun is a white bird with certain well-defined markings of black, blue, red or yellow. The individuals used in StaplesBrown experiments were black and white, the black appearing on the chin and throat, part of the outer flight feathers, a few secondaries and tertiaries, the tail and upper and under tail coverts. The Barb pigeon is self-colored, black, red, yellow, dun or white, with a small beak and the skin around the eyes broad and carunculated. Black Barbs only were used in these experiments. The Fantails used were white. When the Barb Fantail hybrids were bred to the Barb X Nun hybrids no reversionary types were produced. These experiments were discontinued owing to lack of space. However, when Barb Fantail hybrids were mated together some of the offspring had blue feathers. The blue color was chiefly on the tail as described by Animals and Plants under Domestication,'' 2d edition, Vol. I, p. 209. Darwin. A black tail bar was present and the wing coverts and back were of a smoky black color, obscuring the wing bars which are common to the rock pigeon. The reversionary type A similar result in some cases appeared in the F, generation. was obtained by Darwin in the F, generation from a Nun and a red Tumbler. 2 The author explains the fact of the reversionary blue not appearing until the F2 generation in the Barb X Fantail cross, by assuming that the F, individuals contain some element which prevents the appearance of blue. This, he holds, is the factor for black self color, which is epistatic to blue. In the recombination of factors in F2, those combinations containing blue without the black factor produce individuals with blue feathers, while those with the black factor exhibit black feathers but no blue ones. Reference is made to other cases of reversion (sweet Peas and Stocks) in which its occurrence is due to the meeting of complimentary factors. He adds, "In the case of the Barb X Fantail cross the evidence is not yet sufficient to show whether the factors needed to produce the atavistic condition are all present in the Barb and their effect merely hidden by the presence of the black factor, or whether a necessary factor is introduced by the fantail; but the fact that no blues came in the F2 made from an F, (Barb Fantail) F, (Barb X Nun) distinctly suggests that some factor of the blue did come from the Fantail.” 1 The general result of the Barb X Fantail experiments shows a dominance of black and blue to white. This dominance, however, is imperfect, as the majority show some white feathers. In the F2 generation from such crosses, the following types were obtained: 2 Black. Black with some white feathers. Blue. Blue with some white feathers. Red. White with some colored feathers. The significance of the presence or absence of the white feathers is obscure. It was first thought that the white feathers indicated that the bird was producing white-bearing gametes. This is not true in all cases. In matings of blues with white feathers, whites were produced, and a definite proportion of homozygous blues was to be expected. With one exception, however, all the blues produced from these matings showed some white feathers. Some of these were probably homozygous, but it could not be tested without making use of a large number of such birds. The order of dominance was found to be black, blue, red and white. In minor characters, such as irides, color of beak and claws, the author obtained the following results; white irides dominate black, and there is some evidence of correlation between white iris and black plumage. There was also marked correlation observed between the pigment in the beak and to some extent in the claws, and the plumage. In general, white-plumage birds have white beaks and claws. In the case of eye-wattles, red is dominant over flesh color. B. B. HORTON. Stellar Evolution An Account of Some Modern Methods of By GEORGE ELLERY HALE The introduction of photographic methods, the improvement of telescopes, and the rapidly increasing appreciation of the value to astronomy of physical instruments and processes, have revolutionized the observatory. From a simple observing station it has been transformed into a great physical laboratory, where images of the sun and stars are studied with many powerful instruments, and celestial phenomena are experimentally imitated with the aid of electric furnaces and other sources of intense heat. The result has been a great gain in our knowledge of the origin, development, and decay of stars. This book explains in a popular way how the life histories of the sun and stars are investigated. One hundred and four half-tone plates, made from the best astronomical negatives, place before the reader the most recent results of celestial photography in most of its phases. 250 pages, 104 plates, 8vo, cloth, net $4.00, postpaid $4.27. METHODS IN PLANT HISTOLOGY ANIMAL MICROLOGY By CHARLES J. CHAMBERLAIN, Ph.D. of the Department of Botany in the Second Edition, Illustrated. HIS BOOK contains directions for collecting and preparing plant material for microscopic investigation. It is based upon a course in botanical micro-technique, and is the first complete manual to be published on this subject. It aims to meet the requirements, not only of the student who has the assistance of an instructor in a fully equipped laboratory, but also of the student who must work by himself and with limited apparatus. Freehand sectioning, the paraffin method, the celloidin method, and the glycerine method are treated in considerable detail In later chapters specific directions are given for making such preparations as are needed by those who wish to study the plant kingdom from the algae up to the flowering plants. Formulas are given for the reagents commonly used in the histological laboratory. The new edition includes a description of Klebs's PRACTICAL EXERCISES IN MICROSCOPICAL METHODS By MICHAEL F. GUYER An indispensable book for teacher, physician, student, or novice who wishes to learn how to prepare his own material for microscopical examination. There are special chapters on the preparation and examination of embryological material, blood, bacteria, and objects of general interest, and on the collection and preparation of material for the microscopical work in a course in elementary zoology. In an appendix nearly three hundred tissues and organs with directions for properly preparing them for microscopical study are tabu lated. Sufficient account of the theoretical side of microscopy is given to enable the student to get satisfactory results from his microscope. 250 pp., 8vo; net $1.75, postpaid $1.88 Address Dept. 62 The University of Chicago Press, Chicago and New York 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 MAY NUMBER The Categories of Variation. Professor S. J. HOLMES. The General Entomological Ecology of the Indian Corn Plant. 8. A. FORBES. Notes and Literature: Biometrics-Some Recent Studies on Growth. DR. RAYMOND PEARL. Experimental Zoology-Cuénot on the Honey Bee, Professor T. H. MORGAN. The Upholding of Darwin-Poulton and Plate on Evolution, V. L. K CONTENTS OF THE JUNE NUMBER Heredity and Variation in the Simplest Organisms. Professor H. 8. JENNINGS. The Color Sense of the Honey Bee Is Conspicuousness an Advantage to Flowers? JOHN H. LOVELL Variation in the Number of Seeds per Pod in the Broom, Cytisus scoparius. Doctor J. ABTHUB HARRIS. Present Problems in Plant Ecology: The Trend of Ecological Philosophy. Professor The Present Problems of Physiological Plant Notes and Literature: Notes on Evolution, V. L. K. CONTENTS OF THE JULY NUMBER Selection Index Numbers and their Use in Breeding. Dr. RAYMOND PEARL and FRANK M. SURFACE. A Contribution to the Theory of Orthogenesis. Dr. ALEXANDER G. RUTHVEN. The "Presence and Absence" Hypothesis. Dr. GEORGE HARRISON SHULL. Present Problems in Plant Ecology: Vegetation and Altitude. Professor CHARLES H. SHAW. Shorter Articles and Correspondence: Pleistocene Swamp Deposits in Virginia. Dr. EDWARD W. BERRY. Notes and Literature: Heredity-A Case of Non-Mendelian Heredity. Dr. W. J. SPILLMAN. CONTENTS OF THE AUGUST NUMBER The New Flora of Krakatau, Professor DOUGLAS HOUGHTON CAMPBELL. A Male Crayfish with Some Female Organs. Professor E. A. ANDREWS. Present Problems in Plant Ecology: Problems of Local Distribution on Arid Regions. The Relation of the Climatic Factors to Vegetation. Notes and Literature: Recent Experiments on the In- CONTENTS OF SEPTEMBER NUMBER On an Early Tertiary Land-connection between North and South America. Dr. R. F. SCHARF. Notes on the Relations of the Molluscan Fauna of the Peruvian Zoological Province. Dr. WILLIAM HEALEY DALL Remarkable Development of Starfishes on the Northwest American Coast; Hybridism; Multiplicity of Rays; Teratology; Problems in Evolution; Geographical Distribution: Professor A. E. VERRILL. Shorter Articles and Correspondence: Is there a Selective Elimination of Ovaries in the Fruiting of the Leguminosa: Dr. R. HARRIS. Notes and Literature: Ichthyology-Ichthyological Notes, President DAVID STARR JORDAN. Parasitology · Professor H. B. WARD. Plant Cytology-The Permanence of Chromosomes in Plant Cells, Dr. BRADLEY M. DAVIS. 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, Portable Outfit for the Study and Transportation of Anta. EDITH N. BUCKINGHAM Comparison of Canolestes with Polyprotodonta and Diprotodonta, PAULINE H. DEDERER. 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