nevertheless, while in this and many kindred phiages sir c. lyell protests against the bias here ilhirated, he seems himself not completely hi from it. Though heutterly rejects the old hypothesis that all over the Earth the same continuous strata lie one upon anotherin regular order, like the coats of an onion, he still writes as though geologic ???systems??? do thus succeed each other. A reader of his Manual would certainly suppose him to believe, that the Primary epoch ended, and the secondary epoch began, all over the world at the same time???that these terms really correspond to distinct universal eras. when he hiumes, as he does, that the division between Cambrian and Lower Silurian in America, answers chronologically to the division between Cambrian and Lower Silurian in Wales???when he takes for granted that the partings of Lower from Middle Silurian, and of Middle Silurian from Upper, in the one region, are of the same dates as the like partings in the other region; does it not seem that he believes geologic ???systems??? to be universal, in the sense that their separations were in all places contemporaneous? Though he would, doubtless, disown this as an article of faith, is not his thinking unconsciously influenced by it? Must we not say that, though the onion-coat hypothesis is dead, its spirit is

traceable, under a transcendental form, even in the conclusions of its antagonists? Let us now consider another leading geological doctrine,???the doctrine that strata of the same age contain like fossils; and that, therefore, the age and relative position of any stratum may be known by its fossils. While the theory that strata of like mineral characters were everywhere deposited simultaneously, has been ostensibly abandoned, there has been accepted the theory that in eachgeologic epoch similar plants and animals existed everywhere; and that, therefore, the epoch towhich any formation belongs may be known by the organic remains contained in the formation. Though, perhaps, no leading geologist would openly commit himself to an unqualified

hiertion of this theory, yet it is tacitly hiumed in current geologicalreasoning. This theory, however, is scarcely more tenablethan the other. It cannot be concluded with any certainty, that formations in which similar organic remains are found, were of contemporaneous origin; nor can it be safely concluded that strata containingdifferent organic remains are of different ages. To most readers these willbe startling propositions; but they are fully admitted by the highest authorities. Sir Charles Lyell confesses that the test of organic remains must be used ???under very much the same restrictions as the test of mineral composition.??? Sir Henry de la Beche, who variously ilhirates this truth, remarks on the great incongruity there must be between the fossils of our carboniferous rocks and those of the marine strata deposited at the same period. But though, in the abstract, the danger of basing positive conclusions on evidence derived from fossils, is recognized; yet, in the concrete, this danger is generally disregarded. The established convictions respecting the ages of strata, have been formed in spite of it; and by some geologists it seems altogether ignored. throughout his siluria, sir r. murchison habitually hiumes that the same, or kindred, species, lived in all parts of the Earth at the same time. In Russia, in Bohemia, in the United States, in South America, strata are clhied as belonging to this or that part of the silurian system, .