short as to give rise to the vulgar and false hypothesis. of stability and immutability. The transformation is effected by the obligation of the individual to accommodate itself to the altered conditions of life. Fresh circumstances elicit fresh requirements and fresh activities. Great weight must be laid on the use or disuse. of organs. “In every animal still in the course of development, the more frequent and sustained use of an organ gradually fortifies, developes and enlarges it, and endows it with strength proportional to the duration of this use; while the persistent disuse of an organ imperceptibly weakens and deteriorates it, diminishes its efficiency in an increasing ratio, and ultimately destroys it." "And thus," he says, "nature exhibits living beings merely as individuals succeeding one another in generations; species have only a relative stability, and are only transiently immutable."

Lamarck touches upon the struggle of each against all (I. 99, and elsewhere), but does not discover the term Natural Selection. He is fully conscious of the two factors, heredity and adaptation, but his theories and convictions lack the emphasis of detailed evidence. Yet his subtle apprehension of life may be evinced by his interpretation of instinct. According to him, all acts of instinct are effected by incitement, exercised upon the nervous system by acquired inclinations. (penchans acquis); and these acts, not being the product of deliberation, choice, or judgment, certainly and unerringly satisfy the requirements experienced and the inclinations resulting from habit. But if these inclinations to maintain the habit and renew the actions related to them, are once acquired, they are henceforward

transmitted to the individuals by means of reproduction, which maintains the structure and the disposition of the parts in the condition attained, so that the same inclination pre-exists in the young individuals before they put it in practice. This explanation, as Darwin has shown, certainly does not suffice for all the facts of instinct, yet it stands far above the modern "Philosophy of the Unconscious" (Philosophie des Unbewussten), which places the organisms by which the instincts are effectuated, under the sway of an extraneous metaphysical Being who governs it in subservience to design.

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Lyell and Modern Geology--Darwin's Theory of Selection-Beginning of Life.

EVER since mankind has consciously laboured in the field of intellect, pre-eminent men have existed, who, reasoning more rapidly than their contemporaries, have outstripped them in the apprehension of great truths and the recognition of important laws. But it is a great temptation to set too high a value on these anticipations; and in all cases in which these intellectual exploits are concerned, it will be discovered that, so to speak, they floated in the air, and that it was merely a keener scent and a so-called intuition resting on unconscious inferences, which exalted the privileged being above his less sharp-sighted neighbours.

Great scientific crises, revolutions in the domain of intellect, are prepared long beforehand; the watch-word rarely comes too early and is seldom pronounced in accents unintelligible to contemporaries; as a rule, if the change has not been altogether gradual and almost unperceived, but if on the contrary the veil has been suddenly drawn aside by one of these chosen spirits, scales fall, as it were, from the eyes of fellow-labourers and spectators, and the rapidity with which the new

theory makes its way affords the best evidence that it took shape and was proclaimed at the proper moment.

That the doctrine of Descent was likewise no utterly startling apparition, even though it leapt forth from the head of Darwin, its greatest representative, like an armed Minerva of this we have cited at least a few of the many vouchers. That its time had come,-that it was indeed more than time, unless the science of the nature of life, and Biology in general, was to be unduly backward,is shown by the development of Geology, which thirty years prior to Darwin, after many favourable forecasts, struck upon the right road to the knowledge of causes. The doctrine of the formation and evolution of the earth, especially in its earlier phases, during which Life, in the sense generally attached to the word, originated and became permanent on our Planet,-this science of Geology is intimately allied with our important theme. Modern Geology, especially as connected with the name of Charles Lyell, must sooner or later have necessitated an analogous treatment of vegetal and animal lore, and we can only wonder that the crisis was so long delayed. The exposition of the doctrine of Descent must, therefore, be introduced and initiated by a reference, however brief, to modern Geology.

The first edition of Lyell's "Principles of Geology appeared in 1830. The tenth, published in 1866, gave him an opportunity of professing his full adhesion to the Darwinian doctrines, to the development of which he had given so great an impulse. Since 1872, the eleventh edition of this masterpiece has been before the world. It treats of the investigation of the lasting effects of causes now in operation, as data from which inferences.

LYELL AND RECENT GEOLOGY.

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as to past ages may be drawn. Lyell termed these effects an autobiography of the earth. "The forces now operating upon earth are the same in kind and degree as those which in the remotest times produced. geological changes."

Probably, in consequence of the havoc caused by local floods and earthquakes, a belief in great and universal catastrophes was formed at a very early period; and to the Indian and Egyptian legends on this subject Lyell appends the remark, that the traditional connection of such catastrophes with a belief in repeated and universal corruption of morals may be easily explained.

At the end of the last century, the opinion was here and there expressed that the submergence of large extents of land, and the emergence of others, had taken place. slowly; and the doctrine was in preparation that the mineral masses fall into various groups, succeeding one another in definite order. Werner then appeared and founded the special science of "Geognosy." He was not the first to see and teach the regular succession of rocks, but the sensation which he caused was universal. From his time dates the violent controversy of the Vulcanists and Neptunists, and into the midst of this controversy fell Cuvier's great discoveries on the animals of the Tertiary formation in the vicinity of Paris. By the works of Cuvier and Lamarck on fossil animals, the differences betwixt ancient and modern organisms became apparent, and Cuvier's views, zoological as well as geological, gained the victory. The conviction was gradually established that long ages of repose and quiescence alternated on earth with shorter periods of universal catastrophes and revolutions."