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Show EXPLANATIONS. ,. A geologist," he says, " whose observations had been confined to Swizerland miO'ht imaO'ine that the coal meas .. ures were the rnost ~nci~nt of the fossiliferous series. When he extended his investigations to Scotland, he might modify his views so far as to suppose that the Old Red Sandstone marked the beginning of the rocks charged with organic remains. He might, indeed, after a search of many years, admit that here and t~ere. some few and faint traces of fossils had been found In shU older slates in Scotland· but he mio-ht naturally conclude that all pre·existing'fossiliferous for~at_ions must ?every ~nsiguificant, since no pebbles containing organic rema1ns have yet been detected in the conglomerates of the Old Red Sandstone. Great would be the surprise of such a theorist when he learned that in other parts of.Europe, and still more particularly in North Ar:nerica, a great succession of antecedent strata had been discovered, capable, accordina' to some of the ablest palreontologists, of constituting no0 less than three independent groups, each of them as important as the ' Old Red' or Devo~ian syst?m, an~ as distino-uishable from each other by then· organic remains. Yet it would be consistent with methods of gcneralizinCY not uncommon on such subjects, if he still took for gr~ntcd that in the lowest _of these 'Transitio~' or Silurian rocks he had at leno-th arnved at the much-wished-for termination of the fossiliferous series, and that Nature had begun her work precisely at the point where his retrospect happened then to terminat~ . "* . . It is exactly to such theonzers as the Edinburgh revleW· er that his rebuke is applicable. When he asserts the conternporaneousnes9 of the highest mollus)c~ with the ori.o-in of ot•o-anic life, he says-" We ar61 descnbing pheno-me~ n a that 0w e have seen. We have spent years of ac t•I Ve life among these ancient strata-looking for ( an_d we mig.ht say longing for) some arrangement of t~e anc1e~t fosstls which mio-ht fall in with our preconceived notions of a natural as~ending scale. But we looked in vain, and we were weak enough to bow to nature." The weakness consisted in looking only in one little portion of the eart~, and believino- it to be a criterion for all the rest. This writer seems~ yet to have to learn that kno~led~e is to be acquired by communication as well as exam1nahon .. Were a. philosopher (supposing there could be such a bemg) to • Travels in North America, ii., 131. LOWER SILURIAN FOS~ILS. 223 liJ:?it h1s view. of ~an kind to juvenile schools, he micrht w 1lh equal ra~wnaht}: deny that there is any such thin n in hth e world ,a.s hI nfan· tsh Ill arms. " We speal{ of w h a t gw e ave s~en, ' e nng t say~ "_and finding no specime.ns of humanity under three _feet high, we are weak enou rh to bow to natu~·e and behev~ that babes are a mere fan~y." Even talung the English Lower Silurians as he and others would have them taken, it still appears that these ro?ks denote, gt-nerally, a low state of the animal kingdom. It IS customary fo~· t~ose ":'ho take opposite views to speak of the creatures of th1s penod as high-" highly-organi · crustacea and mollusca" is the usual phrase Som ~eu eluding th~ Upper Silurians in their view, teil us th:t :~~ fi~s~ ~ormatwn presen_ts examples of thew hole of the great divisiOns, the fish he1ng held as representing the v ·t br~t~. Of course this ~s .only done through ignoranc:: ~; fOI the ru~pos~ of deceiVIng. Where particulars are overlooked, 1t Is still custom.ary to speak of the earliest fauna ~s one .of an elevated lund. When rigidly examined, it IS not found to be so. In th~ first place, it contains nv fish. . There were seas supporting crustacean and moll uscap. hfe, but ?ttte.rly devoid of a class of tenants who seem able to ltve zn every example of that elem,ent which ~upp~rts meaner. cr~atu.res. !his ~ingle fact, that only Inveitebrated ann~ats now hved, Is surely in itself a strong proof that, II~ the course of nature, time was ne ... ~e~sar~ for the creatw? of the superior creatures. And, If so, 1t undoubtedly 1s a powerful evidence of such a theory of development as that which I have presented. If not so, let m~ hear any equally plausible reason for the grea~ and amaztng fact that ::)eas were for numberless ages dest~tute of ~sh. I fix my opponents dow1~ to the consid .. erabon of th1s fac~, so that no diversion respectino- high mo~lus~s shall ava1l them. But this is not all. The Siluri~ n IS at;t age, as we.re several subsequent ones, of only marme animals. It IS now incontestible from a ~ land: plants found in the Silurians of America, and a r::~ leaf 1n our. own, that there was dry land ; yet no trace of a land anunal appears for ages afterwards. Moreover. though w~ have now ~ pretty full develo'Pment of the fi~st sub·1nngdom, Radtata, we have but an Imperfect on~ ot the two next-namely, the Articulata and Mollusca Not to speak of the utter absence of fresh water and 1a d tpollus~s, and of such lanq articulata all nsects and SJ~i- |
