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Show 402 RECAPITULATION. [CHAP, XIV. tween the extinct and still older species, why is not every geological forniation charged with such links? . Whl does not every collection of fossil remains afford plan~ ~vidence of the gradation and mutation of t~e ~orms of hfe ? .vV e meet with no such evidence, and this IS the most obvious and forcible of the many objections which 1nay be urged against my theory. Why, again,. do whole groups of allied species appear, though certainly they often falsely appear to have come in suddenly on the several geological stages ? Why do we not find g;eat piles of. strata beneath the Silurian system, stored with the remains of the progenitors of the Silurian groups of fossils? For certainly on my theory such st~ata must so1newhere have been deposited at these anment and utterly unknown epochs in the world's history. I can answer these questions and grave objections only on the supposition that the geologi?al record is far Inore in1perfect than most geologist~ believe. . It ~annot be objected that there has not been time suffiment for any amount of organic change; for the lapse of time has been so great as to be utterly inappreciable by the human intellect. The number of specimens in all our museums is absolutely as nothing col? pare~ with t~e countless. generations of countless spemes whiCh certainly have existed. We should not be able to recognise a species as the parent of any one or more species if we were to examine them ever so closely, unless we likewise possessed many of the intermediate links between their past and present state~ ; and these many links we could hardly ever expect to discover, owing to the imperfection of the geological reco;d. Numerous existing doubtful forms could be named whwh are probably varieties; but who will pretend that in future ages so many fossil links will be discovered, ~hat naturalists will be able to decide, on the common view, whether or not these doubtful forms are varieties? As long as most of the links between any two species are unknow~, if any one link or intermediate variety be discovered? It will simply be classed as another and distinct sp.eCies. Only a sinall portion of the world has been geologically explored. Only organic beings of certain classes can be CHAP. XIV.] RECAPITULATION. 403 preserve~ in a fossil condition at least in any g. t ber. Widely ranO'inO' . ' rea num-are often at lirst Io~al5_sBethes vary most,, and varieties . f. . . ' o causes rendering the discov-ery o I~terJ?ediate hnks less likely. Local varieties will not ~pread Into ~ther and distant regions until they are considerably modified and improved . . d h th d d 'f d · . , an w en ey sprea ' 1 . Iscovered In a geological formation, the , wil0l appear as 1f suddenly created there and 'll b l 1 cl asse d as new speci.e s. M. any forma, t Wl e s1mp y 1'ons h b · t erm1' tte n t I· n t h e1· r accu1nulation · and the' avde . ete' n InIam 1· nc 11' ne d to b eI 1' eve, has been sh' orter· tha1nr thu r a 1on ' d urat 1. on of spec1' fi c forms. Successive formaeti oanvse raagre separated from each other by enormous blank · t 1 ef t. .(! .(! 'l' .(! 1n erva s 0 Ime ; 10r 10SSI ~1erous formations, thick enough to resist fut~re deg;adahon1 can be accumulated only where much sedn:nent IS deposited on the subsiding bed of th During the alternate p~riods of elevation and of st~tf~~: ary.level the re~ord Will be blank. During these latter ter1ods th~re Will :probably be more variability in the ?rm~ of hfe ; dunng periods of subsidence more ex-tmcbon. ' " ·With respect to the absence of fossiliferous forn1ations beneath ~he ~owe~t Silurian strata, I can only recur to the hypothesis .g1_ven In the ninth chapter. That the geolo ical record Is Imperfect a~l will admit; but that it is i~perfect .to the degree wh1ch I require, few will be inclined to admit. ~f we look to long enough intervals of time, geolof plainly declares that all species have chanO'ed . and .t ey have changed in the manner which my th~ory requires, for they have changed slowly and in a graduated manner .. We clearly see this in the fossil remains from consecutive formations invariably being much more closely- rela~ed to each other, than are the fossils from formatiOns distant from each other in time. . Sue~ is t~e sun1 ~f the several chief objections and difficulties whiCh may .Justly be urged against my theory· aid I ~ave now briefly recapitulated the answers and ex: P.anatw.ns which can be given to them. I have felt these di~culti~s far too h.eavily during many years to doubt their Weight. But It deserves especial notice that the |