can be the meaning of the cry of "atheism" and of "infidelity" so persistently raised upon all attempts to enlarge the domain of secondary causes, unless it be either the inability of the alarmists to appreciate scientific cogency and value? or a misgiving that the grander truths will cease to be available, as the narrower have been found to be, for serving the purposes of existing institutions, and the selfish comfort of individuals whose habits have become conformed to these institutions, and their support, as they think, synonymous with them?

The tendency to derive, to explain, and to unify, is seen in another line of now developed and established scientific thought, in reference to that part of nature which most nearly concerns us— the organized. The case will illustrate the conclusions we have just reached, while it tends strongly to confirm them. In 1759, Wolff published, in his Theory of Generation, the doctrine of metamorphosis of vegetable forms, or a law of homology for the vegetable world, according to which, bracts, sepals, petals, stamens, pistils, and even the pulp or other fruit of plants, are but modified forms of the leaf; so that the orderly re-appearance of these forms, with each returning season, is to be explained only by the stated recurrence of an established progression of changing conditions. This grand thought of homology, Goethe, not knowing of Wolff's priority, about the year 1790, also conceived, and more completely elaborated; as in 1784, in determining the fact of an intermaxillary bone in the upper jaw of the human skeleton, he had laid the foundation for a like homology in the organization of vertebrate animals; and in accordance with which, the bones of the cranium and of the limbs come to be regarded as modified, and as we may say, differentiated vertebra. This latter thought of the philosopher-poet, Oken and others have the credit of having confirmed and extended.

Both these ideas, after meeting with neglect and the other forms of hard fare allotted to any naked, noble truth coming into the business atmosphere of our planet, have finally triumphed ; they are the basis of morphology, in all our treatises of botany and of anatomy; and to question them now, would simply argue disqualification on the part of the interrogator. Certainly, these views very broadly hint at a derivation, at least, of all plants of related structure and course of developement, each group from a type; and so of all vertebrate animals from some rudimentary

creature having vertebræ without modification or divarication ; and generally, of a plastic and imperceptibly fluent, rather than of a crystalized and rigid conformation of types, in organic nature.

But, in comparison with discoveries that have more recently followed them, these homologies expressed only parts of the whole truth. Within the last twenty-three years, the fruits of the microscope have consolidated in a true science of histology, or developement of organized tissues—a science which, in its present form, rests on the evolution, metamorphosis, and offices of cells, as first observed and rightly conceived by Schleiden and Schwann. The principle of cell-life is recognized as universal for the world of organized beings, as that of gravitation for the larger world of all matter. By this principle, to which we have had occasion previously to refer, not only does all organizable matter come now by action of cells, but all active tissues and organs are in truth but congeries of these minute organisms; these, by their nuclei, or otherwise, reproducing their like as the older sets undergo decay and waste. In fine, every plant, every animal, of course every human being corporeally, is but, so to speak, a less or larger, simpler or more complex (as the case may be), developed, or amplified and differentiated organic CELL! The leaf, or the vertebra, is thus only one of a set of typical forms in which cellgrowth, under certain conditions, tends early to result; the perfect and universal homology resides in the parent cell. By such steps it was that the basis was laid, and the human understanding prepared, for Von Baer's law of developement, namely: That developement proceeds from the like to the unlike,[from the general to the particular, from the homogeneous to the heterogeneous.

All these doctrines relating to the world of living forms had evidently been verging on a last great extension of the principle of unity and derivation, at which we have already hinted; that of an outgrowth, in some past age, of man from some higher quadrumanous or quadrupedal mammal; of these from orders below them, perhaps finally from the vegetable; and possibly, though far less probably, beyond that, by combination of favoring conditions operating on the prepared natural (elements. Indeed, vague successions of this sort were made out, and unnecessarily, in the interest of the worst of causes-the attempt to exclude a Deity from the universe. Lamarck, in somewhat more scientific

spirit, took up the attempt, but failed, by assigning for the necessary variation by which successive forms should arise, a cause soon discovered to be inadequate to the result. He rightly argued that a variation from the parental type, secured by new conditions, could be made permanent, at least for a time, by preserving the conditions, and by interbreeding; while the cause he proposed to account for the variation taking place in the outset, was nothing more than the solicitation of use, and of the external conditions themselves. But how should the mere strivings of the ele. phant to reach, with his short neck, branches above his head, or grass beneath his feet, or any cogency in the facts that the branches and the grass were where they were, develope the trunk of that animal? or how, either, the need of the camel to wander over deserts, or the fact that he found no water on them, develope those additional receptacles in which he now stores away water, as do our ships for voyages upon the thirst-mocking ocean? Again, the principle proved too much. It called for multitudes of adaptations, where none were ever found to occur. The "Vestiges of Creation" has lamely reproduced this halting hypothesis. It proved, in the sum and event, merely a "nine days' wonder." Against such philosophy, even the high priest of Positivism, whose fondness for second causes was scarcely less than overweening, emphatically pronounced. Comte, however, did not live to witness the "agitation of thought" and the trepidation of conventionalisms that have arisen upon the announcement of a new, more labored, and certainly more plausible hypothesis toward the same end-the latest attempt to sustain the assurance of science, in regard to the operations of causes in the realm of living things.

There are those who believe that Mr. Charles Darwin, in his preliminary treatise on the "Origin of Species," has made such attempt with a good degree of success; and, in doing so, has proffered a real clue to certain eons of duration, and pointed towards whole treasuries of possible new thought. It was while reflecting, more than twenty years since, Mr. Darwin tells us, on the distribution of the inhabitants of South America, and the geological relations of these to the past inhabitants of that continent, that the fundamental conception of the new theory became shadowed forth in his mind. In 1837, it occurred to Mr. Darwin to examine all manner of facts bearing on this subject. In 1858,

he presented his results to the British Association; and not long after gave to the world, in view of circumstances which he relates, a preliminary and somewhat hasty outline of his views.

This book, its doctrine, facts and tendencies, have been so long before the public, that we cannot consider it needful, at this time, to add even one more to the volley of reviews proper that have been let off in quick succession since its advent. We shall not be asked so soon again to weigh out unanswerable argument against, nor for, the new theory. Indeed, the assurance may be deemed worthy of some trifling gratitude. But it will be proper, as briefly as may be, to indicate what the theory is, though the author's title pretty plainly suggests it. Mr. Darwin argues that any species multiplying, unchecked, at its possible rate of increase, must soon, to the exclusion of others, take possession of the globe. But there is an incessant struggle between species, and between the individuals of each, for subsistence, for place, for being. In this struggle, the individuals most favored in strength, and in adaptation of form to the means of subsistence falling in their way, will be the most sure to prevail and be perpetuated. By hereditary transmission, these salient qualities will be conveyed to offspring; and by continued exercise or use, aiding this selection under which nature preserves her favorites, or marked forms, the peculiar conformations thus arising will become strengthened, and in time established. In this way, new species, according to the author, will eventually be de veloped, originated from pre-existing ones; and such are, of course, most likely at the same time to be higher in the scale. Thus, then, circumstances, among which competition and conflict hold the chief place, have developed new kinds of organisms. If this be so, the inference follows, that the several existing species need not have been independently created; but all may have come by gradual changes from four or five originals-perhaps from a single one!

We are told that naturalists had already learned to look on genera, orders, tribes, etc., and varieties-all above, and all below the species properly so called-as merely existing in the conceptions of the mind, and not as actual or objective. Mr. Darwin's view would unsettle this last point of fixity in the organic world. He must admit, however, that species have been, and are maintained with a wonderful tenacity. According to him,

the great fact is a likeness of progeny to parents, individually, but subject to variation, and a more or less lasting fixation under natural selection. Three among the hardest questions, we apprehend, that will present themselves to him, are these:-1. A limited derivation in no way escapes the necessity of a direct creation of complete organisms in the outset : how, since it could have no parent-cell, can we imagine the first cell living to have been formed, unless by direct creation? 2. How can we account for the first detachment of a cell or congeries of such, into parts serving different offices?-i. e., whence first came organs? 3. How shall we account for the origination of instinct where previously it was not, and the severance and outgrowth afterward, from this of true intelligence, which instinct is not? It has been remarked that the author is silent upon the bearings of his subject in philosophy and theology. We can conceive no just reason why a like silence should be enjoined on those whom he has addressed; and having said that our purpose was not a review proper, we may add, that it has been rather to take a glance at such bearings and consequences, not of this theory alone, but of all the analogous explo ration and related thought, with which our time and the periods just preceding it have been so largely fraught. We have undertaken this with something, we think, of the feeling which prompted that comprehensive sentiment of Terence

"Homo sum: nihil humani a me alienum puto !"

We must agree with Mr. Darwin that, his view sustained, a revolution must come in Natural History; morphology, paternity, and other of its facts, must acquire new and more real significance; a new field in reference to causes and laws of variation will open; psychology will plant itself on a new basis; and "light will be thrown on the origin of Man, and his history." Again, in his concluding paragraph: "Thus, from the war of nature, from famine and death, the most exalted object which we are capable of conceiving, namely, the production of the higher animals, directly follows. There is a grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning, endless forms most beautiful and most wonderful have been, and are being, evolved."