Illinois, Missouri, Towa, Minnesota, Wisconsin, Michigan, Kansas, Nebraska, California, Oregon, Washington, Arizona, New Mexico, Nevada, Utah, Idaho, Montana, Colorado, and Dacotah. With maps and plans of cities, etc. By Edward H. Hall. New York: D. Appleton & Co. 1867. 12mo. pp. 456.

MISCELLANEOUS.

General Problems of Shades and Shadows. Formed both by Parallel and by Radial Rays; and shown both in Common and in Geometrical Projection; together with the theory of shading. By S. Edward Warren, C. E. New York: J. Wiley & Son, 535 Broadway. 1867. 8vo. pp. 140.

Inquiry into the Origin and Course of Political Parties in the United States. By Martin Van Buren. Edited by his Sons. 8vo. pp. ix., 486. Hurd & Houghton.

Marriage in the United States. By A. Carlier. Translated from the French by B. J. Jeffries. 16mo. pp. xv., 179. Boston: De Vries, Ibarra & Co.

The Negro in the American Rebellion; his heroism and his fidelity. By W. W. Brown. Boston: Lee & Shepard. 1867. 12mo. pp. xvi., 380.

Publications of the American Tract Society, 28 Cornhill, Boston.-Steps in the Upward Way: the Story of Fanny Bell. By Mary Barrett, author of "Shooting at a Mark," etc. 16mo. pp. 279.-Sister's Story. 16mo. pp. 298.-Glimpses of West Africa, with sketches of Missionary Labor. By Rev. Samuel J. Whiton. 16mo. pp. 208.-Friendly Words with Fellow Pilgrims. By James William Kimball. 24mo. pp. 262.

Publications of the American Tract Society, Nassau Street, New York City.Paul Verner; or, the Forge and the Pulpit. Based on Facts. 12mo. pp. 371. -The Hopes of Hope Castle; or, the Times of John Knox and Queen Mary Stuart. By Mrs. S. T. Martyn, author of “The Women of the Bible." Allan Cameron," etc. 12mo. pp. 359.--The Cinnamon Isle Boy. Ry Mrs. E. C. Hutchings. 24mo. pp. 169.-George Wayland, the Little Medicine Carrier. By the author of "Basil," etc. From the Religious Tract Society, London. 24mo. pp. 103.-Bible Prayers. Arranged by Rev. Jonas King, D. D., Missionary at Athens, Greece, etc. 24mo. pp. 182.-The Syrian Leper; or, the Sinner's Malady and the Sinner's Cure. By Rev. E. P. Rogers, D. D. pp. 100.

Rebellion Record.-Nos. 62, 63, and 64 are now published.

24mo.

THE

NEW ENGLANDER.

No. CI.

OCTOBER, 1867.

ARTICLE I.-THE DARWINIAN THEORY OF THE ORIGIN OF SPECIES.

THE whole range of natural science presents no more interesting question than that of the origin of the various forms of life which have flourished in different regions and at different periods. The generally received opinion is, that each species of organism is the result of a special exertion of creative power. The opposition to this view presents itself in the theories of Spontaneous Generation and Transmutation of Species. Of these theories, the former teaches that exceedingly simple organic forms are produced from dead matter by virtue of certain laws or forces inherent in matter. The latter theory teaches that by natural processes of variation one specific type may give rise to another, and thus the great variety of organized existences may have been derived from one or few original forms. The latter theory alone comes strictly within the province of this Article, as Darwin and some of the ablest of his followers unhesitatingly reject the doctrine of spontaneous generation; yet the two views are so naturally associated as constituting together a complete naturalistic theory of the ori

gin of life, and are thus in common adopted or rejected by so large a number of thinkers, that a discussion of the one question cannot be considered complete without some allusion to the other. Especially is this the case in view of Professor H. J. Clark's recent attempt to deduce the transmutation of species as a corollary of spontaneous generation, considering the latter view as proved by the experiments of Professor Wyman. The result of these experiments is regarded by their distinguished author as only equivocal. And, when we consider how contrary to universal experience is the alleged fact, how in all the history of biological science numberless supposed instances of spontaneous generation have disappeared one by one before more accurate investigation, how numerous and important are the grounds of uncertainty in regard to the experiments in question, we cannot accept a doctrine resting on so shadowy a foundation. But, even admitting spontaneous generation, transmutation by no means follows as a logical inference. The two theories naturally suggest each other, but such suggestion is very far from scientific proof. Clark's argument for transmutation involves, then, the twofold fallacy of an illogical conclusion from a false premise.

As the question of permanence or mutability is involved in the very definition of a species, it will be proper here to consider some of the definitions which have been given. The orthodox view is embodied in the words of Linnæus: "Species tot sunt, quot diversas formas ab initio produxit Infinitum Ens; quæ formæ, secundum generationis inditas leges, pro duxere plures, at sibi semper similes."* A species has been defined as a group of individuals descended from a common pair. In order to avoid a disputed question, this definition may be modified as follows: a group of individuals presenting no structural or physiological differences incompatible with possible community of descent. The metaphysical idea which underlies this physical conception is expressed by Professor Dana as "a specific amount or condition of concentered force defined in the act or law of creation."+ This definition prac

*Phil. Bot., 99, 157.

"Thoughts on Species." Am. Jour. Sci., [2], Vol. xxiv., p. 306.

tically coincides with the preceding, for Dana finds in the phenomena of hybridism the criterion of specific identity or diversity.* Radically in opposition to these views, the Transmutationists maintain that a species is but a convenient category under which to group all individuals presenting a certain degree of similarity in structure and physiological relations. On this view species differ from varieties on the one hand, and from genera on the other, only in degree. Varieties are, according to Darwin, "incipient species," and may become true species—that is, may by further variation develop a character so different from that of the parent species as to be worthy of a separate name and place in our systematic arrangements. In like manner species may be developed into genera, genera into families, &c. The position of Agassiz on this question is peculiar. In common with the Transmutationists, he denies that species have any other objective reality than groups of higher degree. In common with the orthodox party, he maintains the permanence of specific types.

The doctrine of the transmutation of species has been brought forward at various times by various authors. Its most prominent advocates before the time of Darwin had been Lamarck and the anonymous author of the "Vestiges of Creation." While these and other authors have agreed on the general principle of the origin of species by descent with modification, they have assigned different causes for the extreme variation required by this theory. Lamarck "attributed something to the direct action of the physical conditions of life, something to the crossing of already existing forms, and much to use and disuse, that is, to the effects of habit. He likewise believed in a law of progressive development."+ The author of the "Vestiges" founded on embryological facts and fictions an hypothesis still more fanciful. But these and all other forms of the development theory, except that proposed by Darwin, have been thoroughly exploded, and are of interest now only as a part of the history of science. But the question has been

"Thoughts on Species." Am. Jour. Sci., [2], Vol. xxiv., p. 309.

+ Darwin on "Origin of Species," p. xiv. (References to this work are in all cases to the fourth English edition).

placed in an entirely different light by the publication of Mr. Darwin's work "On the Origin of Species by means of Natural Selection, or the Preservation of Favored Races in the Struggle for Life." No book that has appeared during the present century, has aroused more of earnest discussion, or done more to stimulate scientific investigation. Whether its views prove

true or false, the originality of the whole conception, the immense learning which is brought to bear upon the argument, the boldness with which every difficulty is encountered, the mingled candor and ingenuity with which objections are answered, will make this work the crowning glory of one already eminent in scientific investigation.

A brief analysis of the Darwinian theory should here be given. The effects of variation under domestication are first discussed, showing what effects man has produced by means of selective breeding, that selection being in some cases methodical, in others unconscious. It is then shown that variation occurs to some extent under nature, though its causes and laws are little understood, and that all variations tend more or less strongly to be inherited. From the high geometrical ratio in which all organic beings tend to increase, it follows that many more individuals are produced than can possibly survive. Hence every individual is exposed to what Darwin very fitly styles the "struggle for life "-a struggle which, consciously or unconsciously, is going on continually with rivals, enemies, and the forces of inorganic nature. If, then, any variation gives to the individual any advantage in the struggle for life, as, for instance, by enabling him more readily to secure his proper food, or to escape his natural enemies, that individual would be more likely to survive than his less fortunately constituted brethren. He would thus be naturally selected to propagate his kind; and, in the ordinary course of inheritance, his peculiarities would tend to be transmitted to his descendants. Successive variations in any desirable direction would thus be accumulated. As the same species might be exposed to different conditions in different portions of its range, this process of variation and natural selection might take various directions, producing divergence of character. As the improved forms would come into competition with the parent forms, the result