membranes and "adrenals" have been essentially rewritten. As a result, the book is improved by many small increments as well as by the new treatment of a few subjects. Among these is the interesting physiological difference between the lungs of birds and of mammals, now properly noted for the first time. In mammals during inspiration the lung expands and draws into its blind terminal respiratory chambers a mixture of fresh and residual air. The residual air greatly dilutes the oxygen which comes in contact with the absorbing blood vessels, and also prevents the carbon dioxide from being expired directly. In birds the lung is a network of anastomosing tubes which are not expansile. Fresh air is drawn through these tubes by the expansion of the air sacs, which are nonrespiratory terminal prolongations of the lung. The lung of the bird may, in a sense, be compared with the respiratory bronchioles of mammals, the mammalian alveoli corresponding with the avian air sacs. Thus the lung of birds is peculiarly adapted for the rapid oxidation correlated with the requirements of flight and with a high body temperature. Other additions of this sort contribute to the value of this edition. L. W. WILLIAMS. (No. 492 was issued January 23, 1908.) 98 II. Fasciations of Known Causation. III. The Aggregate Origination of Parasitic Plants. Dr. CHARLES A. WHITE V. Zoological Progress. VI. Notes and Literature: Heredity-The Possibility of Inheritance through THE SCIENCE PRESS LANCASTER, PA. GARRISON, N. Y. NEW YORK: SUB-STATION 84 Stanford APS 15 1988 THE AMERICAN NATURALIST MSS. intended for publication and books, etc., intended for review should be sent to the Editor of THE AMERICAN NATURALIST, Garrison-on-Hudson, New York. Subscriptions and advertisements should be sent to the publishers. The subscription price is four dollars a year. Foreign postage is fifty cents and Canadian postage twenty-five cents additional. The charge for single copies is thirty-five cents. The advertising rates will be sent on application. Lancaster, Pa. THE SCIENCE PRESS NEW YORK: Sub-Station 84 Garrison, N. Y. Entrance at the Post Office, Lancaster, Pa., as second-class mail matter, applied for. Important New Scientific Books Botany PUBLISHED BY THE MACMILLAN COMPANY The Origin of a Land Flora. A Theory based upon the facts of Alternation. Cloth, gilt top, xi+727 pp., illus., index, 8vo, $5.50 net. NOTE.-A profound study in the morphology of the lowest forms of plants, with special reference to the development of their reproductive systems. The author endeavors to show that the present land flora has originated from an aquatic ancestor, and traces the methods of specialization to the land habit, and the establishment of the forms of the higher plants. A book of the highest importance not only to botanists but to biologists in general. NEW AND STANDARD HAND-BOOKS ON AGRICULTURE, ETC. Elements of Agriculture, Southern and Western. By W. C. WELBORN, B.S., M.S., M.P.A. Cloth, xvi+329 pp., illus., appendix, glossary, index, 12mo, $.75 net. NOTE. This is a thoroughly modern treatise on farming as practiced in the Gulf States, from the point of view of the scientific agriculturist. It is adapted to school use, but is of practical service to any farmer in that part of the country. The author is vice-director of the Texas Experiment Station. Re-issues of the highly valued Hand Books known as the Garden Craft and Rural Science Series, edited by L. H. BAILEY, of Cornell University, Editor of "Cyclopedia of American Horticulture" " Cyclopedia of American Agriculture," etc. The Principles of Fruit Growing. By L. H. BAILEY. Irrigation and Drainage. F. H. KING. Fifth Edition, $1.50 net, by mail $1.68. Principles of Vegetable Gardening. By L. H. BAILEY. Sixth Edition, $1.50 net, by mail $1.68. Bush Fruits. By FRED W. CARD. Fourth Edition, $1.50 net, by mail $1.66. Fertilizers. By EDWARD B. Voorhees. Tenth Edition, $1.25 net, by mail $1.38. Farm Poultry. By GEO. C. WATSON. Sixth Edition, $1.25 net, by mail $1.42. Published The Macmillan Company By 64-66 5th Ave., New York IN "Evolution and Animal Life," by Jordan and Kellogg (page 120), the following words are used: "Given any species, in any region, the nearest related species is not to be found in the same region nor in a remote region, but in a neighboring district separated from the first by a barrier of some sort or at least by a belt of country, the breadth of which gives the effect of a barrier." Substituting the word "kind" for species in the above sentence, thus including geographical subspecies, or nascent species, as well as species clearly definable as such, Dr. J. A. Allen accepts this proposition as representing a general fact in the relations of the higher animals. To this generalization Dr. Allen, in a late number of Science, gives the name of "Jordan's Law." The present writer makes no claim to the discovery of this law. The language above quoted is his, but the idea is familiar to all students of geographical distribution and goes back to the master in that field, Moritz Wagner. This law rests on the fact that the minor differences which separate species and subspecies among animals are due to some form of segregation or isolation. By some barrier or other the members of one group are prevented from interbreeding with those of another minor group or with the mass of the species. As a result, local peculiarities arise. "Migration holds species true, localiza tion lets them slip," or rather leaves them behind in the process of modification. The peculiarities of the parents in an isolated group become intensified by in and in breeding. They become modified in a continuous direction by the selection induced by the local environment. They are possibly changed in one way or another by germinal reactions from impact of environment. At last a new form is recognizable. And this new form is never coincident in its range with the parent species, or with any other closely cognate form, neither is it likely to be in some remote part of the earth. Whenever the range of two such forms overlaps in any degree, the fact seems to find an explanation in reinvasion on the part of one or both of the forms. The obvious immediate element in the formation of species is, therefore, isolation, and behind these are the factors of heredity, of variation, of selection, and others as yet more or less hypothetical involved in the effect of impact of environment on the germ cells themselves. The formation of breeds of sheep as noted by Jordan and Kellogg (p. 82), seems exactly parallel with the formation of species in nature. In like manner, the occasional development of breeds arising from the peculiarities of individuals is possibly parallel with the "mutations" of the evening primrose. Such breeds are the Ancon sheep in Connecticut and the blue-cap Wensleydale1 sheep in Australia. The ontogenetic speciesgroups in which many individuals are simultaneously modified in the same way by like conditions of food or climate-show no permanence in heredity. Such forms, however strongly marked, should, therefore, have no permanent place in taxonomy. The recent studies of Mr. Beebe on the effects of moist air in giving dusky colors to birds serve to illustrate the impermanence of the groups or subspecies characterized by dark shades of color developed in regions of heavy rainfall. It may also be noted in passing that one cause of the 1 Blue Cap, a ram of Leicester-Teeswater parentage, having a blue shade on his head, was the progenitor of a breed having this peculiarity, known as the Wensleydale, in Australia. |