Page images
PDF
[ocr errors]

by Prof. OGDEN N. RooD, to to o to- - o
XXXV. Some experiments and inferences in regard to Binocular
Vision; by Prof. WILLIAM B. Rogers, - -> to- t-

XXXVI. Geographical Notices. No. XIV, - o o o

[ocr errors]
[merged small][merged small][ocr errors][ocr errors][ocr errors][ocr errors]
[merged small][ocr errors]
[merged small][ocr errors][ocr errors][ocr errors]

sailed for California in charge of the Geological Survey of that State.

General Index of Wols. XXI-XXX, Second Series, 424, 425.

Obituary.—Dr. W. P. Holmes, 424.

For a list of the Plates and Errata in Wols. XXI-XXX, see end of Index.

FRRATA.

P. 162, l. 16 from bottom, for “many” read “some.”

“ 167, 1.23 from top, for “best,” read “test.”

“ 174, 1, 18 from top, for “point,” read “part.”

[merged small][merged small][merged small][ocr errors]

ART. I.-On the Origin of Species; by THEOPHILUs PARSONs, Dane Professor of Law in Harvard University, Cambridge, Massachusetts.

IT has frequently occurred in the history of science that some startling theory, which, when first announced, was regarded as the antagonist of received opinions, and became at once the subject of earnest hostility as well as unqualified, approbation, has, after much discussion been importantly qualified and modified, and thus reconciled with views which it seemed to contradict; and when thus shorn of its excess and moderated in its demands, has been generally adopted as an important addition to knowledge. It may yet be so with Mr. Darwin's views.

His theory, stated very briefly, is, that all organisms tend to reproduce themselves in a geometrical ratio, and with such exuberance of life, that each one would speedily fill the earth, if not repressed by constant and powerful causes of destruction. Hence but a very small proportion of seeds or ova which are impregnated are able to mature and reproduce. Therefore there must be a competition, or as he phrases it, a “struggle for life,” among all these impregnated germs of life; and if one in a hundred only lives there must be a reason why that one lives rather than the ninety and nine which perish. This reason must again be frequently, or at least sometimes, that it had some advantage in this “struggle for life,” by a structural or functional difference. That is, it varied from its kindred, in such wise, that it was somewhat easier for it to live, to grow, to mature, and to reproduce, than for them. This difference or variation it must, as a general rule, impart to its offspring. When it be

SECOND SERIES, Vol. XXX, No. 88–JULY, 1860.

came established, the same law of struggle, of advantage, of life, and of death, would operate upon this new and improved variety, and would cause another and a farther improvement. As this law is universal, and must always have operated upon all Organisms from the beginning, not only are varieties established in this way, but so likewise varieties become species, species become genera, and so also orders, classes, families are formed, and thus finally we may suppose that all the organisms of the earth, living and extinct, animal and vegetable, have proceeded from the simplest original form of life. While much interested in Darwin's work and in the discussions and controversies to which it has given rise, it occurred to me to consider whether one of the limitations which he seems to have imposed upon himself, was necessary. He assumes, and reasons exclusively upon the assumption, that the successive changes by which these great results have been brought about have always been minute and slow, and have only become sufficient to reach their consummation, by an indefinite accumulation of effects, through the indefinite periods of time which geology affords them. It seemed to me that this assumption was quite unnecessary, and therefore unphilosophical; and supposing that these changes may sometimes have been much greater, I then inquired what would be the effect of this supposition upon the general theory, that the succession of organized being has from the beginning been produced by generative development. This paper is intended to suggest—and only to suggest—some of the results to which I have come. Upon the question whether I have not departed so widely from the theory of Darwin, that I have no right to use his name, I have nothing to say. I wish only that these suggestions may pass for what they are worth whatever that may be. To say that it is the tendency of all organisms to reproduce their like, but with some difference, would be merely to utter a truism, for there is almost or quite always some family resemblance between offspring of the same parents, and always so much of difference that no two of the offspring are ever undistinguishable from each other. We may say, however, that one certain law of this difference, or variation, is this; that while a slight difference is universal, great difference is less common, and the greater the difference the more rare it is, and therefore the less to be expected in any given instance. The question then arises, how far this difference may go; or to say the same thing in other words, what limit is there to the possible immediate variation of offspring from their parents and kindred? The law of variation is itself variable; and while we have little knowledge of the causes of variation, we have none whatever of the limits to which it may be carried. Indeed, if we assume that there must be some limit to the possible extent of variation, we may infer that it must be a very broad one, from the instances of extreme monstrosity which science has recorded. Let us say, then, that we will assume that there may be as much Variation or aberration as these records prove that there has been, and no more. Perhaps abnormality always seems to us a mischief, and by monstrosity we always understand aberration in a wrong direction; and facts would justify the inference that extreme aberration is usually a degradation. But we have no sufficient reason for saying that this is a law; or, in other words for asserting, that there can never be monstrosity in a right direction; or in yet other words, that the aberrance can never be an improvement and a help. As this seems to me an important principle I restate it. We know that it is the tendency of all organisms to reproduce their kind, but with some difference. We know, for all the improvement in our domestic animals proves it, that this difference may be improvement. We know that this difference may be carried to an enormous extent, as a mischief, because the records of monstrosity prove it; and we do not know that this difference may not be carried to an equal extent in the opposite direction of improvement. My position therefore is precisely this. It is always possible that offspring may be born, differing as much from their parents and kindred in the way of gain, of advantage, and of improvement, as we know that offspring have differed in the way of loss, of hindrance and of degradation; and therefore when I speak of extreme aberration I shall mean by it variation carried to this extent. Admitting this principle as possible, let us proceed with it to consider what may be called the system of Agassiz; using his name only because he has given to it great development and full illustration. Take first his assertion that there must have been in each geological age many new creatures; say if you please an hundred or a thousand, and consider this as proved and admitted. Still it leaves wholly untouched the question how these new creatures were created. And be the answer what it may, that answer so far as it is only an answer to this question, leaves the assertion of Agassiz untouched. But if we bring to the question, how were these creatures created? the possibility of aberrant yariation of offspring in the direction of improvement, we bring to it one answer. For example: suppose the time to have come when there is to be a new creation, and it is to be a dog, or rather two dogs, which will be the parents of all dogs. How shall they be created? We may say of this either of five things. One is, that we do not know, and never can know, and had better not inquire. This does not seem any answer. A second is, that they will be created “by chance.” This also seems to me no answer, because chance is a word only and not a thing. A

« PreviousContinue »