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Show 40 I'ISHES ABUNDAN14 • the salmon. It is no_t premature ~o remark.~ how broadly these facts seel? t? ~1nt a~ a parity of law affecting the pr?gress of an IndiVIdual fretus of one of the 1nore perfect animals. It is equally ascertained of the types of being prevalent in the ol~ red, ~s of those of the preceding system, that they are uniform In the . corresponding strata of distant parts of the earth; for Instance, Russm and North America. . _In the old red sandstone,. the marine plants, of which taint traces are observable I~ the Silurians, continue to appear. I~ would se.Cfn as If _less change took place in the vegetat!on than In t!1e animals of those early seas; ~nd [or tlns, as Mr. Miller has remarked, it is easy to nnagine reasons. For example, an infusion of lime into the sea would destroy animal life, but be favorable to ve- ,getation. ~s yet there were no land animals or plants, and for tlu_s the presumable reason is, that no dry land as yet ex1sted. We are not left to make this inference solely from the absence of .land anim~ls and plants ; in the arrangem~ nt of the ynmary (stratified) rocks, we have further evidence of It. That these rocks were formed in a generally horizontal position, we are as well assured as that they were formed at the bottom of seas. But they a~e always found greatly inclined in position, tilted up aga1nst the slopes of the granitic masses which are beneath t_hem in geo!ogical order, though often shooting up to a.h1gher pomt In the ~tl?osphere. No doubt can be e~terta1ned t_hat these granitic masses, fonning our prin· c1pal mounta1n ranges, have been protruded from below, or, at lea~t, thrust muc~ further up? since the deposition, of the pnmary rocks. fhe p~·otrusion 'Yas what tilted up the pnmary rocks; and the Inference IS of course unav_ oidable, th~t these mountains have riser{ chiefly, at \east, . s1ncc the pr1mary rocks were laid down. It is remarkable that, while the primary rocks thus incline towards gra~itic nuclei or. axes, the strata higher in the series rest agamst thes~ agatn, generally at a less inclination or n.)ne at all, showing that these strata were laid down after the s:nelling mount~in eminences had, by their protrusion, blted up the pnmary strata. And thus it may be said an era of local UJ?throwing of ~he prim.itive 1.\nd (perha~~s) central matter of our planet, Is established as happen· ~~g about the close of the primary strata, and beginning of • ERA OF THE OLD RED ~ANDSTONE. ..., the next ensuing s:rstem. It may be called the Era oj the Oldest Mountaz~, or more boldly, {)f the formatinn of the detached portwns of dry land over the hitherto watery sur~ace of the globe-an important part of the designs of Provtdence, for which the time was now apparently come. It may be remarJ{ed, that volcanic disturbances and.protrusions of t~·~p tool{ place throughout the whole perwd of the depostt101_1 of th.e J?l'tmary :L'Ocl'is; but they were upon a comparatively hm1ted scale, and probabl_y all took pl~c~ unde.L· water. It was only now that th~ central granihc masses of the great mountain ranges were th~own up, carrying up with .. them broken edges of the pnmary strata; a process whtch seems to have had thia difference from the other~ that it was the effect of a more tremendous force exerted at a lower depth in the earth, and generally acting in lines pervading a considerable portion of the e.arth's su1·face. We shall by-and-hy see that the prot~s1on ~f some of ·the mountain ranges wat .not completed, or d1d not stop at that period. There is no part of geological science more clear than that which refers to the ag.es of mountains. It is as certain that the Grampian mountains of Scotland are older than the Alp9 and the Appenines, as i.t is that civilization had visited Italy and harl enabled her to subdue the world, while Scotland was the residence of" roving barbarians." The Pyrenees, Carpathians, and other ranges of continental ~u~op~, are all yo~nger. than the Grampians, or even the Insignificant Mendip H1lls of southern England. Stratification tells this tale as plainly as Livy tells the history of the Roman republic. It tens us-to use the words ot Professor Phil:ips-that at the time when the Grampians sent streams and detritus to straits where now the Forth and Clyde meet, the greater part of Europe was a wide ocean. !he last three systems-called, in England, the Cumbrian, Silurian, and D~voPian, and collectively the palreozoic rocks, from their containing the remains of the earliest inhabitants of the globe-are of vast thickness; in England r,ot much less than 30,000 feet, or nearly six miles. In other parts of the world, as we have seen, the earliest of these systems alone is of much greater deptharguing an 'enormous profundity in the ocean in which they were formed. |
