Page:Popular Science Monthly Volume 40.djvu/869

Rh the negro in America; others relate to the interests of Liberia; the Congo State; the aims of education and the lives of noted leaders. All are well thought out, and can not fail to be helpful to the people for whom they were written.

three great names in the history of biologic evolution are those of Lamarck, Darwin, and Weismann. The first edition of this work, which was soon exhausted, appeared as a single volume, and at a much higher price. The present volume is more desirable, as one gets with it a list of references to the numerous discussions that its appearance immediately evoked, and which has continued at a high tension and without interruption in the numbers of Nature and other periodicals ever since. One can understand the cause of the intense feeling shown in these discussions by glancing at the titles of these essays which have appeared at various times since 1881: The Duration of Life, 1881; On Heredity, 1883; Life and Death, 1883; The Continuity of the Germ-plasm as the Foundation of a Theory of Heredity, 1885; The Significance of Sexual Reproduction in the Theory of Natural Selection, 1886; On the Number of Polar Bodies and their Significance in Heredity, 1887; On the Supposed Botanical Proofs of the Transmission of Acquired Characters, 1888; and The Supposed Transmission of Mutilations, 1888.

While any one of these subjects was sufficient to excite endless controversy, the last two essays were bound to bring on an irreconcilable conflict. A principle that we had regarded as settled, namely, that traits acquired by the individual during life could be transmitted to his offspring, is not only denied by Weismann, but this comer-stone of natural selection being knocked away, the edifice, to our astonishment, does not tumble, but remains just as steady without it. The author's judicial and temperate way, his admission of doubt, where doubt exists, inspires confidence in his deductions. In ending his essay on the Duration of Life, he says: "And so, in discussing this question of life and death, we come at last—as in all provinces of human research—upon problems which appear to us to be, at least for the present, insoluble. In fact, it is the quest after perfected truth, not its possession, that falls to our lot, that gladdens us> fills up the measure of our life, nay! hallows it."

In closing his essay on Life and Death he says: "Life is continuous, and not periodically interrupted: ever since its first appearance upon the earth, in the lowest organisms, it has continued without break; the forms in which it is manifested have alone undergone change. Every individual alive to-day—even the very highest—is to be derived in an unbroken line from the first and lowest forms."

It is impossible within the limits of a brief review to make even an abstract of the writer's arguments. The low price of the work enables every student to possess it. To the few remaining opponents of evolution among thoughtful students who are unfamiliar with the facts and details cited, this hot discussion between the Weismannians and the Neo-Lamarckians must seem fratricidal, whereas it may be compared to a band of earnest travelers perfectly united in their efforts to reach the same goal, and, coming to a number of cross-roads, heatedly discuss which is the right road, firmly resolved to follow that when demonstrated, even if many have to finally retrace their steps in order to do so. The acrimony and satire which have been excited by these discussions are in consequence of the fact that there is no half-way ground upon which the combatants can unite. It must end in absolute defeat to one or the other side. Great credit is due to Edward B. Poulton, Selmar Schönland, and Arthur E. Shipley, all accomplished biologists, for their connection with the work as editors.

simple description on the title-page of this work—"a book about mountains for general readers"—aptly characterizes the contents and style of the volume. The author has written especially for those who enjoy mountain scenery, and has aimed to heighten their enjoyment by increasing their understanding of what they see. He has