light that stole through a rift in the clouds of the primeval tempest, destined to be closed out again for a geologic age.

This enormous interval of time, down to the close of the Huronian, relieved of its absolute sterility of life by only a single species certainly known, we designate as Eozoic TIME.

"The curtain falls, and the scene is changed." The crust, now becoming too large for the ever-shrinking nucleus, settles down to a closer fitting around it. The envelope, of course, must wrinkle, and the wrinkles must protrude their ridges, in some cases, above the waters. The horizontality of the primeval strata is thus broken. In some instances they are burst asunder, and the molten granite is poured out through the fissure. In other cases a huge back is simply elevated a moderate distance above the level of the sea. Weary of his old position, the giant, in adjusting himself in his new one, leaves his elbows protruding. Indeed, if we may extend this ugly figure, he may be represented as settling himself with an entire arm protruding above the waters which swept over North America. Beginning at the coast of Labrador, the arm— or ancient ridge of land-extends southwest to the north shore of Lake Huron. Here is the elbow. The fore-arm and hand extend thence northwesterly toward the Arctic Ocean. So it seems to be an arrangement of Nature that "Johnny Bull" shall continue to thrust his elbows into the sides of Young America! We acquiesce, for the present, in this arrangement. Meanwhile, other spirits will be summoned from the "vasty deep," and teeming life will appear upon the stage in the next act of the drama.

THE

HE spirits have come forth. The life-giving afflutus has been breathed into multitudes of organic forms which now teem in the PALEOZOIC sea.

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"Say, mysterious Earth! oh say, great Mother and Goddess!
Was it not well with thee then, when first thy lap was ungirdled,
Thy lap to the genial Heaven, the day that he wooed thee and won thee?
Fair was thy blush, the fairest and first of the blushes of morning;
Deep was the shudder, oh Earth! the throe of thy self-retention ;
July thou strovest to flee, and didst seek thyself at thy centre!
Mightier far was the joy of thy sudden resilience; and forthwith
Myriad myriads of lives teemed forth from the mighty embracement,
Thousand fold tribes of dwellers, impelled by thousand fold instincts,
Filled as a dream the wide waters.

The long period of almost total lifelessness-the Eozoic TIME-it will be remembered, was brought to a close by the upheaval of a long ridge of land, extending from the coast of Labrador to the northern shores of the great lakes, and thence northwest to the Arctic Sea. Corresponding upheavals took place on other continents. A convulsion could not jar one half the globe without being felt upon the other half, and hence it is that all the grand revolu tions of geology were simultaneous, and the histories of different continents are divided into corresponding chapters. We confine our attention, however, to North America. The germinal ridge consists of an axis or nucleus of granitic material, and on each side of a series of gneissoid and other eozoic strata sloping like the roof of a house from the central and highest part. We know that this upheaval took place after the deposition of the eozoic strata, because those strata could not have been deposited in their present

D

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tilted position (Fig. 19). We know that it took place before the deposition of the next series of strata, because

.0

SKETCHES OF CREATION.

b

Fig. 19. Disturbed condition of Eozoic Strata.

a. Eozoic strata, tilted and contorted by disturbances occurring before the deposition of the Paleozoic strata, b, c, d. e, e, e. Faults or dislocations of Eozoic and Paleozoic strata, evidently of later date than the contortions of a.

these strata were not tilted by the upheaval, but continue to present their horizontal edges against the inclined faces. of the eozoic beds. Thus the precise relative period of this upheaval is fixed.

Consider the geography of the North American continent at this date. An angular ridge of land (Fig. 20) is all that

Fig. 20. The Germ of the North American Continent.

a, a. The two branches of the continent. b, b. Islands. (The modern continent is indicated by dotted lines, the rivers by broken lines.)

then existed. The Rocky Mountains and the Alleghanies were not yet born from the deep. Where were the United States? Where the broad valley of the Mississippi, and the wide-extended plains of the far West? Beneath the wave, and receiving the sediments of the same sea which rolled over the future sites of Babylon, and Tyre, and Athens, and the seven hills of the "Eternal City." The generations of men yet slumbered in the chambers of futurity. The order of Providence had assigned them their position in the grand procession of life which was now beginning to move, and the scouts of which had passed by in the preceding age; but we must wait for man till a long line of grotesque and marvelous forms has marched before our view.

The van of this procession was led by some of the humbler forms of God's creation. We shall indeed look in vain for a type of existence of simpler mould than the Laurentian Eozoön. It is likely that beings akin to this accompanied the shoals of higher forms which sprang into existence at the morning dawn of the Silurian Age. But if they lived, the record of their existence has been effaced from the earth. Like the deeds and the sufferings of the men who kept company with the extinct quadrupeds of Europe, and chased the fur-clad mammoth across the steppes of Siberia, their very existence is reached only by conjecture, and the activities which made up life with them have all been locked up with the arcana of the past. The creatures whose relics we have disentombed were more highly gifted than the Eozoön, and were launched into being under a great variety of forms. The oldest Silurian rocks of North America are perhaps those revealed to science upon the island of Newfoundland by the assiduity of the Canadian geologists. Their records have been recently studied by the paleontologist Billings, of Montreal, an investigator eminent for acuteness and for the importance of his paleon

tological discoveries. An assemblage of strata named by him the "St. John's Group" is described as underlying rocks that had heretofore been regarded as forming the very base of the Silurian system in America. These St. John's strata may probably be regarded as inclosing the remains of the first considerable fauna that ever lived within the limits of America. Our knowledge of these primeval relics is as yet very imperfect*, being limited to one crinoid, two brachiopods, and half a dozen genera of trilobites. Though they mark generally a great simplicity of organization, one can not but be astonished that in the very outset of animalization upon our globe so high a rank and so great variety of types should have been manifested. If we are to judge from that which is known rather than that which is conjectured, we are compelled to conclude that the varied forms of animal life did not come into being by a gradual evolution from the Eozoön, but as so many original ut

Fig. 21. Paradoxides Harlani (×%). St. terances of the all-skilled Artificer of creation.

John's Trilobite.

Of the "Potsdam group" of strata [see Appendix, Note III., and the organic remains which they inclose, we have learned somewhat more. The "Potsdam sandstone" at the

* Billings (E.): "Catalogues of the Silurian Fossils of the island of Anticosti," p. 79.