第17章

Indeed，atthemomentofDarwin’swritinganewandveryinstructivechapterofthegeologicrecordwasbeingpresentedtothepublic——achapterwhichforthefirsttimebroughtmanintothestory。In1859Dr。

Falconer，thedistinguishedBritishpaleontologist，madeavisittoAbbeville，inthevalleyoftheSomme，incitedbyreportsthatforadecadebeforebadbeensentoutfromtherebyM。BoucherdePerthes。Thesereportshadtodowiththeallegedfindingofflintimplements，clearlytheworkofman，inundisturbedgravel-

beds，inthemidstoffossilremainsofthemammothandotherextinctanimals。WhatFalconersawthereandwhatcameofhisvisitmaybestbetoldinhisownwords:

"InSeptemberof1856ImadetheacquaintanceofmydistinguishedfriendM。BoucherdePerthes，"

wroteDr。Falconer，"ontheintroductionofM。DesnoyersatParis，whenhepresentedtometheearliervolumeofhisAntiquitesceltiques，etc。，withwhichIthusbecameacquaintedforthefirsttime。IwasthenfreshfromtheexaminationoftheIndianfossilremainsofthevalleyoftheJumna；andtheantiquityofthehumanracebeingasubjectofinteresttoboth，weconversedfreelyaboutit，eachfromadifferentpointofview。M。dePerthesinvitedmetovisitAbbeville，inordertoexaminehisantediluviancollection，fossilandgeological，gleanedfromthevalleyoftheSomme。

ThisIwasunabletoaccomplishthen，butIreserveditforafutureoccasion。

"InOctober，1856，havingdeterminedtoproceedtoSicily，IarrangedbycorrespondencewithM。BoucherdePerthestovisitAbbevilleonmyjourneythroughFrance。IwasatthetimeinconstantcommunicationwithMr。PrestwichabouttheproofsoftheantiquityofthehumanraceyieldedbytheBroxhamCave，inwhichhetookalivelyinterest；andIengagedtocommunicatetohimtheopinionsatwhichIshouldarrive，aftermyexaminationoftheAbbevillecollection。

M。dePerthesgavemethefreestaccesstohismaterials，withunreservedexplanationsofallthefactsofthecasethathadcomeunderhisobservation；andhavingconsideredhisMenchecourtSection，takenwithsuchscrupulouscare，andidentifiedthemolarsofelephasprimigenius，whichhehadexhumedwithhisownhandsdeepinthatsection，alongwithflintweapons，presentingthesamecharacterassomeofthosefoundintheBroxhamCave，Iarrivedattheconvictionthattheywereofcontemporaneousage，althoughIwasnotpreparedtogoalongwithM。dePerthesinallhisinferencesregardingthehieroglyphicsandinanindustrialinterpretationofthevariousotherobjectswhichhehadmetwith。"[4]

ThatDr。FalconerwasmuchimpressedbythecollectionofM。dePerthesisshowninacommunicationwhichhesentatoncetohisfriendPrestwich:

"Ihavebeenrichlyrewarded，"heexclaims。"Hiscollectionofwroughtflintimplements，andoftheobjectsofeverydescriptionassociatedwiththem，farexceedseverythingIexpectedtohaveseen，especiallyfromasinglelocality。Hehasmadegreatadditions，sincethepublicationofhisfirstvolume，inthesecond，whichInowhavebyme。HeshowedmeflinthatchetswhichHEHADDUGUPwithhisownhands，mixedINDISCRIMINATELY

withmolarsofelephasprimigenius。Iexaminedandidentifiedplatesofthemolarsandtheflintobjectswhichweregotalongwiththem。Abbevilleisanout-of-the-wayplace，verylittlevisited；andtheFrenchsavantswhomeethiminParislaughatMonsieurdePerthesandhisresearches。Butafterdevotingthegreaterpartofadaytohisvastcollection，Iamperfectlysatisfiedthatthereisagreatdealoffairpresumptiveevidenceinfavorofmanyofhisspeculationsregardingtheremoteantiquityoftheseindustrialobjectsandtheirassociationwithanimalsnowextinct。

M。Boucher’shotelis，fromthegroundfloortogarret，acontinuedmuseum，filledwithpictures，mediaevalart，andGaulishantiquities，includingantediluvianflint-knives，fossil-bones，etc。If，duringnextsummer，youshouldhappentobepayingavisittoFrance，letmestronglyrecommendyoutocometoAbbeville。I

amsureyouwouldberichlyrewarded。"[5]

ThisletterarousedtheinterestoftheEnglishgeologists，andinthespringof1859PrestwichandMr。

(afterwardsSirJohn)EvansmadeavisittoAbbevilletoseethespecimensandexamineatfirsthandtheevidencesaspointedoutbyDr。Falconer。"TheevidenceyieldedbythevalleyoftheSomme，"continuesFalconer，inspeakingofthisvisit，"wasgoneintowiththescrupulouscareandsevereandexhaustiveanalysiswhicharecharacteristicofMr。Prestwich’sresearches。

TheconclusionstowhichhewasconductedwerecommunicatedtotheRoyalSocietyonMay12，1859，inhiscelebratedmemoir，readonMay26thandpublishedinthePhilosophicalTransactionsof1860，which，inadditiontoresearchesmadeinthevalleyoftheSomme，containedanaccountofsimilarphenomenapresentedbythevalleyoftheWaveney，nearHoxne，inSuffolk。

Mr。EvanscommunicatedtotheSocietyofAntiquariesamemoironthecharacterandgeologicalpositionofthe’FlintImplementsintheDrift，’whichappearedintheArchaeologiafor1860。TheresultsarrivedatbyMr。Prestwichwereexpressedasfollows:

"First。Thattheflintimplementsaretheresultofdesignandtheworkofman。

"Second。Thattheyarefoundinbedsofgravel，sand，andclay，whichhaveneverbeenartificiallydisturbed。

"Third。Thattheyoccurassociatedwiththeremainsofland，fresh-water，andmarinetestacea，ofspeciesnowliving，andmostofthemstillcommoninthesameneighborhood，andalsowiththeremainsofvariousmammalia——afewspeciesnowliving，butmoreofextinctforms。

"Fourth。Thattheperiodatwhichtheirentombmenttookplacewassubsequenttothebowlder-clayperiod，andtothatextentpost-glacial；andalsothatitwasamongthelatestingeologicaltime——oneapparentlyanteriortothesurfaceassumingitspresentform，sofarasitregardssomeoftheminorfeatures。"[6]

ThesereportsbroughtthesubjectoftheverysignificanthumanfossilsatAbbevilleprominentlybeforethepublic；whereasthepublicationsoftheoriginaldiscoverer，BoucherdePerthes，bearingdateof1847，hadbeenaltogetherignored。Anewaspectwasthusgiventothecurrentcontroversy。

AsDr。Falconerremarked，geologywasnowpassingthroughthesameordealthatastronomypassedintheageofGalileo。ButthetimeswerechangedsincethedaywhentheauthoroftheDialogueswashumbledbeforetheCongregationoftheIndex，andnownoIndexLibrorumProhibitorumcouldavailtohidefromeagerhumaneyessuchpagesofthegeologicstoryasNatureherselfhadspared。Eagersearcherswereturningtheleaveswithrenewedzealeverywhere，andwithnosmallmeasureofsuccess。Inparticular，interestattachedjustatthistimetoahumanskullwhichDr。FuhlrotthaddiscoveredinacaveatNeanderthaltwoorthreeyearsbefore——acraniumwhichhaseversincebeenfamousastheNeanderthalskull，thetypespecimenofwhatmodernzoologistsaredisposedtoregardasadistinctspeciesofman，Homoneanderthalensis。LikeothersofthesametypesincediscoveredatSpy，itissingularlysimianincharacter——low-arched，withrecedingforeheadandenormous，protuberanteyebrows。

WhenitwasfirstexhibitedtothescientistsatBerlinbyDr。Fuhlrott，in1857，itshumancharacterwasdoubtedbysomeofthewitnesses；ofthat，however，thereisnopresentquestion。

ThisinterestingfindservedtorecallwithfreshsignificancesomeobservationsthathadbeenmadeinFranceandBelgiumalonggenerationearlier，butwhosebearingshadhithertobeenignored。In1826

MM。TournalandChristolhadmadeindependentdiscoveriesofwhattheybelievedtobehumanfossilsinthecavesofthesouthofFrance；andin1827

Dr。SchmerlinghadfoundinthecaveofEngis，inWestphalia，fossilbonesofevengreatersignificance。

Schmerling’sexplorationshadbeenmadewiththeutmostcare，andpatience。AtEngishehadfoundhumanbones，includingskulls，intermingledwiththoseofextinctmammalsofthemammothperiodinawaythatleftnodoubtinhismindthatalldatedfromthesamegeologicalepoch。Hebadpublishedafullaccountofhisdiscoveriesinanelaboratemonographissuedin1833。

Butatthattime，asitchanced，humanfossilswereunderabanaseffectualasanyeverpronouncedbycanonicalindex，thoughoffardifferentorigin。TheoracularvoiceofCuvierhaddeclaredagainsttheauthenticityofallhumanfossils。Someofthebonesbroughthimforexaminationthegreatanatomisthadpettishlypitchedoutofthewindow，declaringthemfitonlyforacemetery，andthathadsettledthematterforageneration:theevidencegatheredbylesserworkerscouldavailnothingagainstthedecisionrenderedattheDelphiofScience。Butnoban，scientificorcanonical，canlongerresistthegerminativepowerofafact，andsonow，afterthreedecadesofsuppression，thetruthwhichCuvierhadburiedbeneaththeweightofhisridiculeburstitsbonds，andfossilmanstoodrevealed，ifnotasaflesh-and-blood，atleastasaskeletalentity。

Thereceptionnowaccordedourprehistoricancestorbytheprogressiveportionofthescientificworldamountedtoanovation；buttheunscientificmasses，ontheotherhand，notwithstandingtheirusualfondnessfortracingremotegenealogies，stillgavethemenofEngisandNeanderthalthecoldshoulder。Norwereallofthegeologistsquiteagreedthatthecontemporaneityofthesehumanfossilswiththeanimalswhoseremainshadbeenmingledwiththemhadbeenfullyestablished。Thebarepossibilitythatthebonesofmanandofanimalsthatlongprecededhimhadbeenswepttogetherintotheeavesinsuccessiveages，andinsomemysteriouswayintermingledthere，wasclungtobytheconservativesasalastrefuge。Buteventhissmallmeasureofsecuritywassoontobedeniedthem，forin1865twoassociatedworkers，M。EdouardLartetandMr。HenryChristy，inexploringthecavesofDordogne，unearthedabitofevidenceagainstwhichnosuchobjectioncouldbeurged。Thismomentousexhibitwasabitofivory，afragmentofthetuskofamammoth，onwhichwasscratchedarudebutunmistakableoutlineportraitofthemammothitself。Ifalltheevidenceastoman’santiquitybeforepresentedwassuggestivemerely，hereatlastwasdemonstration；

forthecave-dwellingmancouldnotwellhavedrawnthepictureofthemammothunlesshehadseenthatanimal，andtoadmitthatmanandthemammothhadbeencontemporarieswastoconcedetheentirecase。

Sosoon，therefore，asthefullimportofthismostinstructiveworkofartcametoberealized，scepticismastoman’santiquitywassilencedforalltimetocome。

Inthegenerationthathaselapsedsincethefirstdrawingofthecave-dwellerartistwasdiscovered，evidencesofthewide-spreadexistenceofmaninanearlyepochhavemultipliedindefinitely，andto-daythepaleontologisttracesthehistoryofourracebackbeyondtheironandbronzeages，throughaneolithicorpolished-stoneage，toapaleolithicorrough-stoneage，withconfidencebornofunequivocalknowledge。Andhelooksconfidentlytothefutureexploreroftheearth’sfossilrecordstoextendthehistorybackintovastlymoreremoteepochs，foritislittledoubtedthatpaleolithicman，themostancientofourrecognizedprogenitors，isamoderncomparedtothosegenerationsthatrepresentedtherealchildhoodofourrace。

THEFOSSIL-BEDSOFAMERICA

Coincidentlywiththediscoveryofthesehighlysuggestivepagesofthegeologicstory，otherstillmoreinstructivechapterswerebeingbroughttolightinAmerica。

ItwasfoundthatintheRockyMountainregion，instratafoundinancientlakebeds，recordsofthetertiaryperiod，orageofmammals，hadbeenmadeandpreservedwithfulnessnotapproachedinanyotherregionhithertogeologicallyexplored。TheserecordsweremadeknownmainlybyProfessorsJosephLeidy，O。C。

Marsh，andE。D。Cope，workingindependently，andmorerecentlybynumerousyoungerpaleontologists。

Theprofusionofvertebrateremainsthusbroughttolightquitebeggarsallpreviousexhibitsinpointofmerenumbers。ProfessorMarsh，forexample，whowasfirstinthefield，foundthreehundrednewtertiaryspeciesbetweentheyears1870and1876。Meanwhile，incretaceousstrata，heunearthedremainsofabouttwohundredbirdswithteeth，sixhundredpterodactyls，orflyingdragons，somewithaspreadofwingsoftwenty-

fivefeet，andonethousandfivehundredmosasaursofthesea-serpenttype，someofthemsixtyfeetormoreinlength。InasinglebedofJurassicrock，notlargerthanagood-sizedlecture-room，hefoundtheremainsofonehundredandsixtyindividualsofmammals，representingtwentyspeciesandninegenera；whilebedsofthesameagehaveyieldedthreehundredreptiles，varyingfromthesizeofarabbittosixtyoreightyfeetinlength。

ButthechiefinterestofthesefossilsfromtheWestisnottheirnumberbuttheirnature；foramongthemarenumerousillustrationsofjustsuchintermediatetypesoforganismsasmusthaveexistedinthepastifthesuccessionoflifeontheglobehasbeenanunbrokenlinealsuccession。Herearereptileswithbat-likewings，andotherswithbird-likepelvesandlegsadaptedforbipedallocomotion。Herearebirdswithteeth，andotherreptiliancharacters。Inshort，whatwithreptilianbirdsandbirdlikereptiles，thegapbetweenmodernreptilesandbirdsisquitebridgedover。Inasimilarway，variousdiversemammalianforms，asthetapir，therhinoceros，andthehorse，arelinkedtogetherbyfossilprogenitors。And，mostimportantofall，ProfessorMarshhasdiscoveredaseriesofmammalianremains，occurringinsuccessivegeologicalepochs，whichareheldtorepresentbeyondcaviltheactuallineofdescentofthemodernhorse；tracingthelineageofourone-toedspeciesbackthroughtwoandthreetoedforms，toanancestorintheeoceneorearlytertiarythathadfourfunctionaltoesandtherudimentofafifth。Thisdiscoveryistoointerestingandtooimportantnottobedetailedatlengthinthewordsofthediscoverer。

MarshDescribestheFossilHorse"Itisawell-knownfact，"saysProfessorMarsh，"thattheSpanishdiscoverersofAmericadiscoverednohorsesonthiscontinent，andthatthemodernhorse(Equuscaballus，Linn。)wassubsequentlyintroducedfromtheOldWorld。Itis，however，notsogenerallyknownthattheseanimalshadformerlybeenabundanthere，andthatlongbefore，intertiarytime，nearrelativesofthehorse，andprobablyhisancestors，existedinthefarWestincountlessnumbersandinamarvellousvarietyofforms。Theremainsofequinemammals，nowknownfromthetertiaryandquaternarydepositsofthiscountry，alreadyrepresentmorethandoublethenumberofgeneraandspecieshithertofoundinthestrataoftheeasternhemisphere，andhenceaffordmostimportantaidintracingoutthegenealogyofthehorsesstillexisting。

"TheanimalsofthisgroupwhichlivedinAmericaduringthethreediversionsofthetertiaryperiodwereespeciallynumerousintheRockyMountainregions，andtheirremainsarewellpreservedintheoldlakebasinswhichthencoveredsomuchofthatcountry。

Themostancientoftheselakes——whichextendedoveraconsiderablepartofthepresentterritoriesofWyomingandUtah——remainedsolongineocenetimesthatthemudandsand，slowlydepositedinit，accumulatedtomorethanamileinverticalthickness。Inthesedepositsvastnumbersoftropicalanimalswereentombed，andheretheoldestequineremainsoccur，fourspeciesofwhichhavebeendescribed。ThesebelongtothegenusOrohippus(Marsh)，andareallofadiminutivesize，hardlybiggerthanafox。Theskeletonsoftheseanimalsresemblethatofthehorseinmanyrespects，muchmoreindeedthananyotherexistingspecies，but，insteadofthesingletoeoneachfoot，socharacteristicofallmodernequines，thevariousspeciesofOrohippushadfourtoesbeforeandthreebehind，allofwhichreachedtheground。Theskull，too，wasproportionatelyshorter，andtheorbitwasnotenclosedbehindbyabridgeofbone。Therewerefiftyfourteethinall，andthepremolarswerelargerthanthemolars。Thecrownsoftheseteethwereveryshort。

Thecanineteethweredevelopedinbothsexes，andtheincisorsdidnothavethe"mark"whichindicatestheageofthemodernhorse。Theradiusandulnawereseparate，andthelatterwasentirethroughthewholelength。Thetibiaandfibulaweredistinct。Intheforefootallthedigitsexceptthepollex，orfirst，werewelldeveloped。Thethirddigitisthelargest，anditscloseresemblancetothatofthehorseisclearlymarked。

Theterminalphalanx，orcoffin-bone，hasashallowmedianboneinfront，asinmanyspeciesofthisgroupinthelatertertiary。Thefourthdigitexceedsthesecondinsize，andthesecondismuchtheshortestofall。Itsmetacarpalboneisconsiderablycurvedoutward。

Inthehind-footofthisgenustherearebutthreedigits。Thefourthmetatarsalismuchlargerthanthesecond。

"Thelargernumberofequinemammalsnowknownfromthetertiarydepositsofthiscountry，andtheirregulardistributionsthroughthesubdivisionsofthisformation，affordagoodopportunitytoascertaintheprobabledescentofthemodernhorse。TheAmericanrepresentativeofthelatteristheextinctEquusfraternus(Leidy)，aspeciesalmost，ifnotwholly，identicalwiththeOldWorldEquuscaballus(Linnaeus)，towhichourrecenthorsebelongs。HuxleyhastracedsuccessfullythelatergenealogyofthehorsethroughEuropeanextinctforms，butthelineinAmericawasprobablyamoredirectone，andtherecordismorecomplete。Taking，then，astheextremeofaseries，Orohippusagilis(Marsh)，fromtheeocene，andEquusfraternus(Leidy)，fromthequaternary，intermediateformsmaybeintercalatedwithconsiderablecertaintyfromthirtyormorewell-markedspeciesthatlivedintheinterveningperiods。Thenaturallineofdescentwouldseemtobethroughthefollowinggenera:

Orohippus，oftheeocene；MiohippusandAnchitherium，ofthemiocene；Anchippus，Hipparion，Protohippus，Phohippus，ofthepliocene；andEquus，quaternaryandrecent。

Themostmarkedchangesundergonebythesuccessiveequinegeneraareasfollows:First，increaseinsize；second，increaseinspeed，throughconcentrationoflimbbones；third，elongationofheadandneck，andmodificationsofskull。TheeoceneOrohippuswasthesizeofafox。MiohippusandAnchitherium，fromthemiocene，wereaboutaslargeasasheep。HipparionandPliohippus，ofthepliocene，equalledtheassinheight；whilethesizeofthequaternaryEquuswasfullyuptothatofamodernhorse。

"Theincreaseofspeedwasequallywellmarked，andwasadirectresultofthegradualformationofthelimbs。Thelatterwereslowlyconcentratedbythereductionoftheirlateralelementsandenlargementoftheaxialbone，untiltheforceexertedbyeachlimbcametoactdirectlythroughitsaxisinthelineofmotion。Thisconcentrationiswellseen——e。g。，inthefore-limb。Therewas，first，achangeinthescapulaandhumerus，especiallyinthelatter，whichfacilitatedmotioninonelineonly；second，anexpansionoftheradiusandreductionoftheulna，untiltheformeraloneremainedentireandeffective；third，ashorteningofallthecarpalbonesandenlargementofthemedianones，insuringafirmerwrist；fourth，anincreaseofsizeofthethirddigit，attheexpenseofthoseofeachside，untiltheformeralonesupportedthelimb。

"Suchis，inbrief，ageneraloutlineofthemoremarkedchangesthatseemedtohaveproducedinAmericathehighlyspecializedmodernEquusfromhisdiminutivefour-toedpredecessor，theeoceneOrohippus。

Thelineofdescentappearstohavebeendirect，andtheremainsnowknownsupplyeveryimportantintermediateform。Itis，ofcourse，impossibletosaywithcertaintythroughwhichofthethree-toedgeneraofthepliocenethatlivedtogetherthesuccessioncame。

Itisnotimpossiblethatthelatterspecies，whichappeargenericallyidentical，arethedescendantsofmoredistinctpliocenetypes，asthepersistenttendencyinalltheearlierformswasinthesamedirection。

Consideringtheremarkabledevelopmentofthegroupthroughthetertiaryperiod，anditsexistenceevenlater，itseemsverystrangethatnoneofthespeciesshouldhavesurvived，andthatweareindebtedforourpresenthorsetotheOldWorld。"[7]

PALEONTOLOGYOFEVOLUTION

Theseandsuch-likerevelationshavecometolightinourowntime——are，indeed，stillbeingdisclosed。Needlesstosay，noindexofanysortnowattemptstoconcealthem；yetsomethinghasbeenaccomplishedtowardsthesameendbythepublicationofthediscoveriesinSmithsonianbulletinsandintechnicalmemoirsofgovernmentsurveys。Fortunately，however，theresultshavebeenrescuedfromthatpartialoblivionbysuchinterpretersasProfessorsHuxleyandCope，sotheunscientificpublichasbeenallowedtogainatleastaninklingofthewonderfulprogressofpaleontologyinourgeneration。

ThewritingsofHuxleyinparticularepitomizetherecord。In1862headmittedcandidlythatthepaleontologicalrecordasthenknown，sofarasitbearsonthedoctrineofprogressivedevelopment，negativesthatdoctrine。In1870hewasableto"softensomewhattheBrutus-likeseverity"ofhisformerverdict，andtoassertthattheresultsofrecentresearchesseem"toleaveaclearbalanceinfavorofthedoctrineoftheevolutionoflivingformsonefromanother。"Sixyearslater，whenreviewingtheworkofMarshinAmericaandofGaudryinPikermi，hedeclaredthat，"ontheevidenceofpaleontology，theevolutionofmanyexistingformsofanimallifefromtheirpredecessorsisnolongeranhypothesis，butanhistoricalfact。"In1881heassertedthattheevidencegatheredinthepreviousdecadehadbeensounequivocalthat，hadthetransmutationhypothesisnotexisted，"thepaleontologistwouldhavehadtoinventit。"

Sincethenthedelversafterfossilshavepiledproofonproofinbewilderingprofusion。Thefossil-bedsinthe"badlands"ofwesternAmericaseeminexhaustible。

AndintheConnecticutRiverValleynearrelativesofthegreatreptileswhichProfessorMarshandothershavefoundinsuchprofusionintheWestlefttheirtracksonthemud-flats——sinceturnedtosandstone；

andafewskeletonsalsohavebeenfound。Thebodiesofaraceofgreatreptilesthatwerethelordsofcreationoftheirdayhavebeendissipatedtotheirelements，whilethechanceindentationsoftheirfeetastheyracedalongtheshores，merefootprintsonthesands，havebeenpreservedamongthemostimperishableofthememory-tabletsoftheworld。

OftheothervertebratefossilsthathavebeenfoundintheeasternportionsofAmerica，amongthemostabundantandinterestingaretheskeletonsofmastodons。

OftheseoneofthelargestandmostcompleteisthatwhichwasunearthedinthebedofadrainedlakenearNewburg，NewYork，in1845。Thisspecimenwaslargerthantheexistingelephants，andhadtuskselevenfeetinlength。ItwasmountedanddescribedbyDr。

JohnC。Warren，ofBoston，andhasbeenfamousforhalfacenturyasthe"Warrenmastodon。"

ButtothestudentofracialdevelopmentasrecordedbythefossilsallthesesporadicfindshavebutincidentalinterestascomparedwiththerichWesternfossil-

bedstowhichwehavealreadyreferred。Fromrecordshereunearthed，theracialevolutionofmanymammalshasinthepastfewyearsbeenmadeoutingreaterorlessdetail。ProfessorCopehastracedtheancestryofthecamels(which，liketherhinoceroses，hippopotami，andsundryotherformsnowspokenofas"OldWorld，"

seemtohavehadtheiroriginhere)withmuchcompleteness。

Alemuroidformofmammal，believedtobeofthetypefromwhichmanhasdescended，hasalsobeenfoundinthesebeds。Itisthoughtthatthedescendantsofthiscreature，andoftheother"Old-World"

formsabovereferredto，foundtheirwaytoAsia，probably，assuggestedbyProfessorMarsh，acrossabridgeatBeringStrait，tocontinuetheirevolutionontheotherhemisphere，becomingextinctinthelandoftheirnativity。Theape-manfossilfoundinthetertiarystrataoftheislandofJavain1891bytheDutchsurgeonDr。EugeneDubois，andnamedPithecanthropuserectus，mayhavebeenadirectdescendantoftheAmericantribeofprimitivelemurs，thoughthisisonlyaconjecture。

Notallthestrangebeastswhichhavelefttheirremainsinour"badlands"arerepresentedbylivingdescendants。

Thetitanotheres，orbrontotheridae，forexample，agigantictribe，offshootsofthesamestockwhichproducedthehorseandrhinoceros，representedtheculminationofalineofdescent。Theydevelopedrapidlyinageologicalsense，andflourishedaboutthemiddleofthetertiaryperiod；then，touseAgassiz’sphrase，"timefoughtagainstthem。"ThestoryoftheirevolutionhasbeenworkedoutbyProfessorsLeidy，Marsh，Cope，andH。F。Osborne。

ArecentbitofpaleontologicalevidencebearingonthequestionoftheintroductionofspeciesisthatpresentedbyDr。J。L。Wortmaninconnectionwiththefossillineageoftheedentates。ItwassuggestedbyMarsh，in1877，thatthesecreatures，whosemodernrepresentativesareallSouthAmerican，originatedinNorthAmericalongbeforethetwocontinentshadanylandconnection。Thestagesofdegenerationbywhichtheseanimalsgraduallylosttheenamelfromtheirteeth，comingfinallytotheuniqueconditionoftheirmoderndescendantsoftheslothtribe，areillustratedbystrikinglygradedspecimensnowpreservedintheAmericanMuseumofNaturalHistory，asshownbyDr。Wortman。

Alltheseandamultitudeofotherrecentobservationsthatcannotbeevenoutlinedheretellthesamestory。

Withoneaccordpaleontologistsofourtimeregardthequestionoftheintroductionofnewspeciesassolved。

AsProfessorMarshhassaid，"todoubtevolutiontodayistodoubtscience；andscienceisonlyanothernamefortruth。"

Thusthethirdgreatbattleoverthemeaningofthefossilrecordshascometoaconclusion。Againthereisatrucetocontroversy，anditmayseemtothecasualobserverthatthepresentstandofthescienceoffossilsisfinalandimpregnable。Butdoesthisreallymeanthatafullsynopsisofthestoryofpaleontologyhasbeentold？Ordoweonlyawaitthecomingofthetwentieth-centuryLamarckorDarwin，whoshallattackthefortifiedknowledgeofto-daywiththebatteriesofanewgeneralization？

IV。THEORIGINANDDEVELOPMENTOFMODERNGEOLOGY

JAMESHUTTON

Onemightnaturallysupposethatthescienceoftheearthwhichliesatman’sfeetwouldatleasthavekeptpacewiththescienceofthedistantstars。

Butperhapstheveryobviousnessofthephenomenadelayedthestudyofthecrustoftheearth。Itistheunattainablethatalluresandmystifiesandenchantsthedevelopingmind。Theproverbialchildspurnsitstoysandcriesforthemoon。

Sointhoseclosingdaysoftheeighteenthcentury，whenastronomershadgonesofartowardsexplainingthemysteriesofthedistantportionsoftheuniverse，wefindachaosofopinionregardingthestructureandformationoftheearth。Guesseswerenotwantingtoexplaintheformationoftheworld，itistrue，but，withoneortwoexceptions，thesearebizarreindeed。Onetheorysupposedtheearthtohavebeenatfirstasolidmassofice，whichbecameanimatedonlyafteracomethaddashedagainstit。Othertheoriesconceivedtheoriginalglobeasamassofwater，overwhichfloatedvaporscontainingthesolidelements，whichinduetimewereprecipitatedasacrustuponthewaters。Inaword，thevariousschemessupposedtheoriginalmasstohavebeenice，orwater，oraconglomerateofwaterandsolids，accordingtotherandomfanciesofthetheorists；

andthefinalseparationintolandandwaterwasconceivedtohavetakenplaceinallthewayswhichfancy，quiteuncheckedbyanytenabledata，couldinvent。

WhateverimportantchangesinthegeneralcharacterofthesurfaceoftheglobewereconceivedtohavetakenplacesinceitscreationweregenerallyassociatedwiththeMosaic:deluge，andthetheorieswhichattemptedtoexplainthiscatastrophewerequiteonaparwiththosewhichdealtwitharemoterperiodoftheearth’shistory。

Somespeculators，holdingthattheinterioroftheglobeisagreatabyssofwaters，conceivedthatthecrusthaddroppedintothischasmandhadthusbeeninundated。Othersheldthattheearthhadoriginallyrevolvedonaverticalaxis，andthatthesuddenchangetoitspresentpositionbadcausedthecatastrophicshiftingofitsoceans。Butperhapsthefavoritetheorywasthatwhichsupposedacomettohavewanderedneartheearth，andinwhirlingaboutittohavecarriedthewaters，throughgravitation，inavasttideoverthecontinents。

Thusblindlygropedthemajorityofeighteenth-centuryphilosophersintheirattemptstostudywhatwenowtermgeology。Deludedbytheolddeductivemethods，theyfoundednotascience，buttheghostofascience，asimmaterialandasunlikeanythinginnatureasanyotherphantomthatcouldbeconjuredfromthedepthsofthespeculativeimagination。Andallthewhilethebeckoningearthlaybeneaththefeetofthesevisionaries；buttheireyeswerefixedinair。

Atlast，however，therecameamanwhohadthepenetrationtoseethatthephantomscienceofgeologyneededbeforeallelseabodycorporeal，andwhotooktohimselfthetaskofsupplyingit。ThiswasDr。JamesHutton，ofEdinburgh，physician，farmer，andmanufacturingchemist——patient，enthusiastic，level-headeddevoteeofscience。Inspiredbyhisloveofchemistrytostudythecharacterofrocksandsoils，Huttonhadnotgonefarbeforetheearthstoodrevealedtohiminanewlight。Hesaw，whatgenerationsofpredecessorshadblindlyrefusedtosee，thatthefaceofnatureeverywhere，insteadofbeingrigidandimmutable，isperenniallyplastic，andyearbyyearisundergoingmetamorphicchanges。Thesolidestrocksaredaybydaydisintegratedslowly，butnonethelesssurely，bywindandrainandfrost，bymechanicalattritionandchemicaldecomposition，toformthepulverizedearthandclay。Thissoilisbeingsweptawaybyperennialshowers，andcarriedofftotheoceans。Theoceansthemselvesbeatontheirshores，andeatinsidiouslyintothestructureofsandsandrocks。Everywhere，slowlybutsurely，thesurfaceofthelandisbeingwornaway；itssubstanceisbeingcarriedtoburialintheseas。

Shouldthisdenudationcontinuelongenough，thinksHutton，theentiresurfaceofthecontinentsmustbewornaway。ShoulditbecontinuedLONGENOUGH！Andwiththatthoughtthereflashesonhismindaninspiringconception——theideathatsolartimeislong，indefinitelylong。Thatseemsasimpleenoughthought——almostatruism——tothetwentieth-centurymind；

butitrequiredgeniustoconceiveitintheeighteenth。

Huttonponderedit，graspeditsfullimport，andmadeitthebasisofhishypothesis，his"theoryoftheearth。"

MODERNGEOLOGY

Thehypothesisisthis——thattheobservedchangesofthesurfaceoftheearth，continuedthroughindefinitelapsesoftime，mustresultinconveyingallthelandatlasttothesea；inwearingcontinentsawaytilltheoceansoverflowthem。Whatthen？Why，asthecontinentsweardown，theoceansarefillingup。Alongtheirbottomsthedetritusofwastedcontinentsisdepositedinstrata，togetherwiththebodiesofmarineanimalsandvegetables。Whymightnotthisdebrissolidifytoformlayersofrocks——thebasisofnewcontinents？

Whynot，indeed？

Buthaveweanyproofthatsuchformationofrocksinanocean-bedhas，infact，occurred？Tobesurewehave。Itisfurnishedbyeverybedoflimestone，everyoutcroppingfragmentoffossil-bearingrock，everystratifiedcliff。Howelsethanthroughsuchformationinanocean-bedcametheserockstobestratified？

Howelsecametheytocontaintheshellsofoncelivingorganismsimbeddedintheirdepths？Theancients，findingfossilshellsimbeddedintherocks，explainedthemasmerefreaksof"natureandthestars。"Lesssuperstitiousgenerationshadrepudiatedthisexplanation，buthadfailedtogiveatenablesolutionofthemystery。ToHuttonitisamysterynolonger。Tohimitseemsclearthatthebasisofthepresentcontinentswaslaidinancientsea-beds，formedofthedetritusofcontinentsyetmoreancient。

ButtwolinksarestillwantingtocompletethechainofHutton’shypothesis。Throughwhatagencyhastheoozeoftheocean-bedbeentransformedintosolidrock？

andthroughwhatagencyhasthisrockbeenliftedabovethesurfaceofthewatertoformnewcontinents？

Huttonlooksabouthimforaclew，andsoonhefindsit。Everywhereaboutusthereareoutcroppingrocksthatarenotstratified，butwhichgiveevidencetotheobservanteyeofhavingoncebeeninamoltenstate。

Differentmineralsaremixedtogether；pebblesarescatteredthroughmassesofrocklikeplumsinapudding；

irregularcrevicesinotherwisesolidmassesofrock——so-calledveinings——areseentobefilledwithequallysolidgraniteofadifferentvariety，whichcanhavegottenthereinnoconceivableway，soHuttonthinks，butbyrunninginwhilemolten，asliquidmetalisrunintothemouldsofthefounder。Eventhestratifiedrocks，thoughtheyseeminglyhavenotbeenmelted，giveevidenceinsomeinstancesofhavingbeensubjectedtotheactionofheat。Marble，forexample，isclearlynothingbutcalcinedlimestone。

Withsuchevidencebeforehim，Huttonisatnolosstocompletehishypothesis。Theagencywhichhassolidifiedtheocean-beds，hesays，issubterraneanheat。

Thesameagency，actingexcessively，hasproducedvolcaniccataclysms，upheavingocean-bedstoformcontinents。Theruggedandunevensurfacesofmountains，thetiltedandbrokencharacterofstratifiedrockseverywhere，arethestandingwitnessesofthesegiganticupheavals。

Andwiththistheimaginedcycleiscomplete。Thecontinents，wornawayandcarriedtotheseabytheactionoftheelements，havebeenmadeoverintorocksagainintheocean-beds，andthenraisedoncemoreintocontinents。Andthismassivecycle，InHutton’sscheme，issupposedtohaveoccurrednotonceonly，butoverandoveragain，timeswithoutnumber。Inthisuniqueviewoursisindeedaworldwithoutbeginningandwithoutend；itscontinentshavebeenmakingandunmakinginendlessseriessincetimebegan。

Huttonformulatedhishypothesiswhileyetayoungman，notlongafterthemiddleofthecentury。Hefirstgaveitpublicityin1781，inapaperbeforetheRoyalSocietyofEdinburgh:

"Asolidbodyoflandcouldnothaveansweredthepurposeofahabitableworld，"saidHutton，"forasoilisnecessarytothegrowthofplants，andasoilisnothingbutthematerialcollectedfromthedestructionofthesolidland。Thereforethesurfaceofthislandinhabitedbyman，andcoveredbyplantsandanimals，ismadebynaturetodecay，indissolvingfromthathardandcompactstateinwhichitisfound；andthissoilisnecessarilywashedawaybythecontinualcirculationofthewaterrunningfromthesummitsofthemountainstowardsthegeneralreceptacleofthatfluid。

"Theheightsofourlandarethuslevelledwithourshores，ourfertileplainsareformedfromtheruinsofthemountains；andthosetravellingmaterialsarestillpursuedbythemovingwater，andpropelledalongtheinclinedsurfaceoftheearth。Thesemovablematerials，deliveredintothesea，cannot，foralongcontinuance，restupontheshore，forbytheagitationofthewinds，thetides，andthecurrentseverymovablethingiscarriedfartherandfartheralongtheshelvingbottomofthesea，towardstheunfathomableregionsoftheocean。

"Ifthevegetablesoilisthusconstantlyremovedfromthesurfaceoftheland，andifitsplaceisthentobesuppliedfromthedissolutionofthesolidearthashererepresented，wemayperceiveanendtothisbeautifulmachine；anendarisingfromnoerrorinitsconstitutionasaworld，butfromthatdestructibilityofitslandwhichissonecessaryinthesystemoftheglobe，intheeconomyoflifeandvegetation。

"Theimmensetimenecessarilyrequiredforthetotaldestructionofthelandmustnotbeopposedtothatviewoffutureeventswhichisindicatedbythesurestfactsandmostapprovedprinciples。Time，whichmeasureseverythinginouridea，andisoftendeficienttoourschemes，istonatureendlessandasnothing；itcannotlimitthatbywhichaloneithasexistence；

andasthenaturalcourseoftime，whichtousseemsinfinite，cannotbeboundedbyanyoperationthatmayhaveanend，theprogressofthingsuponthisglobethatinthecourseofnaturecannotbelimitedbytimemustproceedinacontinualsuccession。Weare，therefore，toconsiderasinevitablethedestructionofourland，sofaraseffectedbythoseoperationswhicharenecessaryinthepurposeoftheglobe，consideredasahabitableworld，andsofaraswehavenotexaminedanyotherpartoftheeconomyofnature，inwhichotheroperationsandadifferentintentionmightappear。

"Wehavenowconsideredtheglobeofthisearthasamachine，constructeduponchemicalaswellasmechanicalprinciples，bywhichitsdifferentpartsarealladapted，inform，inquality，andquantity，toacertainend——anendattainedwithcertaintyofsuccess，andanendfromwhichwemayperceivewisdomincontemplatingthemeansemployed。

"Butisthisworldtobeconsideredthusmerelyasamachine，tolastnolongerthanitspartsretaintheirpresentposition，theirproperformsandqualities？

Ormayitnotbealsoconsideredasanorganizedbodysuchashasaconstitution，inwhichthenecessarydecayofthemachineisnaturallyrepairedintheexertionofthoseproductivepowersbywhichithasbeenformed？

"Thisistheviewinwhichwearenowtoexaminetheglobe；toseeiftherebe，intheconstitutionoftheworld，areproductiveoperationbywhicharuinedconstitutionmaybeagainrepairedandadurationofstabilitythusprocuredtothemachineconsideredasaworldcontainingplantsandanimals。

"Ifnosuchreproductivepower，orreformingoperation，afterdueinquiry，istobefoundintheconstitutionofthisworld，weshouldhavereasontoconcludethatthesystemofthisearthhaseitherbeenintentionallymadeimperfectorhasnotbeentheworkofinfinitepowerandwisdom。"[1]

This，then，wastheimportantquestiontobeanswered——thequestionoftheconstitutionoftheglobe。

Toaccomplishthis，itwasnecessary，firstofall，toexaminewithoutprejudicethematerialalreadyinhand，addingsuchnewdiscoveriesfromtimetotimeasmightbemade，butalwaysapplyingtothewholeunvaryingscientificprinciplesandinductivemethodsofreasoning。

"Ifwearetotakethewrittenhistoryofmanfortherulebywhichweshouldjudgeofthetimewhenthespeciesfirstbegan，"saidHutton，"thatperiodwouldbebutlittleremovedfromthepresentstateofthings。

TheMosaichistoryplacesthisbeginningofmanatnogreatdistance；andtherehasnotbeenfound，innaturalhistory，anydocumentbywhichhighantiquitymightbeattributedtothehumanrace。Butthisisnotthecasewithregardtotheinferiorspeciesofanimals，particularlythosewhichinhabittheoceananditsshores。Wefindinnaturalhistorymonumentswhichprovethatthoseanimalshadlongexisted；andwethusprocureameasureforthecomputationofaperiodoftimeextremelyremote，thoughfarfrombeingpreciselyascertained。

"Inexaminingthingspresent，wehavedatafromwhichtoreasonwithregardtowhathasbeen；andfromwhatactuallyhasbeenwehavedataforconcludingwithregardtothatwhichistohappenhereafter。

Therefore，uponthesuppositionthattheoperationsofnatureareequableandsteady，wefind，innaturalappearances，meansforconcludingacertainportionoftimetohavenecessarilyelapsedintheproductionofthoseeventsofwhichweseetheeffects。

"Itisthusthat，infindingtherelicsofseaanimalsofeverykindinthesolidbodyofourearth，anaturalhistoryofthoseanimalsisformed，whichincludesacertainportionoftime；andfortheascertainingthisportionoftimewemustagainhaverecoursetotheregularoperationsofthisworld。Weshallthusarriveatfactswhichindicateaperiodtowhichnootherspeciesofchronologyisabletoremount。

"Wefindthemarksofmarineanimalsinthemostsolidpartsoftheearth，consequentlythosesolidpartshavebeenformedaftertheoceanwasinhabitedbythoseanimalswhicharepropertothatfluidmedium。

If，therefore，weknewthenaturalhistoryofthesesolidparts，andcouldtracetheoperationsoftheglobebywhichtheyhavebeenformed，wewouldhavesomemeansforcomputingthetimethroughwhichthosespeciesofanimalshavecontinuedtolive。Buthowshallwedescribeaprocesswhichnobodyhasseenperformedandofwhichnowrittenhistorygivesanyaccount？

Thisisonlytobeinvestigated，first，inexaminingthenatureofthosesolidbodiesthehistoryofwhichwewanttoknow；and，secondly，inexaminingthenaturaloperationsoftheglobe，inordertoseeiftherenowexistsuchoperationsas，fromthenatureofthesolidbodies，appeartohavebeennecessaryfortheirformation。

"Therearefewbedsofmarbleorlimestoneinwhichmaynotbefoundsomeofthoseobjectswhichindicatethemarineobjectofthemass。If，forexample，inamassofmarbletakenfromaquarryuponthetopoftheAlpsorAndesthereshallbefoundonecockle-shellorpieceofcoral，itmustbeconcludedthatthisbedofstonehasbeenoriginallyformedatthebottomofthesea，asmuchasanotherbedwhichisevidentlycomposedalmostaltogetherofcockle-shellsandcoral。Ifonebedoflimestoneisthusfoundtohavebeenofmarineorigin，everyconcomitantbedofthesamekindmustbealsoconcludedtohavebeenformedinthesamemanner。

"Inthosecalcareousstrata，whichareevidentlyofmarineorigin，therearemanypartswhichareofsparrystructure——thatistosay，theoriginaltextureofthosebedsinsuchplaceshasbeendissolved，andanewstructurehasbeenassumedwhichispeculiartoacertainstateofthecalcareousearth。Thischangeisproducedbycrystallization，inconsequenceofapreviousstateoffluidity，whichhassodisposedtheconcertingpartsastoallowthemtoassumearegularshapeandstructurepropertothatsubstance。AbodywhoseexternalformhasbeenmodifiedbythisprocessiscalledaCRYSTAL；onewhoseinternalarrangementofpartsisdeterminedbyitissaidtobeofaSPARRY

STRUCTURE，andthisisknownfromitsfracture。

"Thereare，inalltheregionsoftheearth，hugemassesofcalcareousmatterinthatcrystallineformorsparrystateinwhich，perhaps，novestigecanbefoundofanyorganizedbody，noranyindicationthatsuchcalcareousmatterhasbelongedtoanimals；butasinothermassesthissparrystructureorcrystallinestateisevidentlyassumedbythemarinecalcareoussubstancesinoperationswhicharenaturaltotheglobe，andwhicharenecessarytotheconsolidationofthestrata，itdoesnotappearthatthesparrymassesinwhichnofiguredbodyisformedhavebeenoriginallydifferentfromothermasses，which，beingonlycrystallizedinpart，andinpartstillretainingtheiroriginalform，haveampleevidenceoftheirmarineorigin。

"Weareled，inthismanner，toconcludethatallthestrataoftheearth，notonlythoseconsistingofsuchcalcareousmasses，butotherssuperincumbentuponthese，havehadtheiroriginatthebottomofthesea。

"Thegeneralamountofourreasoningisthis，thatnine-tenths，perhaps，orninety-nine-hundredths，ofthisearth，sofaraswesee，havebeenformedbynaturaloperationsoftheglobeincollectingloosematerialsanddepositingthematthebottomofthesea；consolidatingthosecollectionsinvariousdegrees，andeitherelevatingthoseconsolidatedmassesabovethelevelonwhichtheywereformedorloweringthelevelofthatsea。

"Letusnowconsiderhowfartheotherpropositionofstratabeingelevatedbythepowerofheatabovetheleveloftheseamaybeconfirmedfromtheexaminationofnaturalappearances。Thestrataformedatthebottomoftheoceanarenecessarilyhorizontalintheirposition，ornearlyso，andcontinuousintheirhorizontaldirectionorextent。Theymaybechangedandgraduallyassumethenatureofeachother，sofarasconcernsthematerialsofwhichtheyareformed，buttherecannotbeanysuddenchange，fracture，ordisplacementnaturallyinthebodyofastratum。Butifthestrataarecementedbytheheatoffusion，anderectedwithanexpansivepoweractingbelow，wemayexpecttofindeveryspeciesoffracture，dislocation，andcontortioninthosebodiesandeverydegreeofdeparturefromahorizontaltowardsaverticalposition。

"Thestrataoftheglobeareactuallyfoundineverypossibleposition:forfromhorizontaltheyarefrequentlyfoundvertical；fromcontinuoustheyarebrokenandseparatedineverypossibledirection；andfromaplanetheyarebentanddoubled。Itisimpossiblethattheycouldhaveoriginallybeenformed，bytheknownlawsofnature，intheirpresentstateandposition；

andthepowerthathasbeennecessarilyrequiredfortheirchangehasnotbeeninferiortothatwhichmighthavebeenrequiredfortheirelevationfromtheplaceinwhichtheyhavebeenformed。"[2]

Fromallthis，therefore，Huttonreachedtheconclusionthattheelevationofthebodiesoflandabovethewaterontheearth’ssurfacehadbeeneffectedbythesameforcewhichhadactedinconsolidatingthestrataandgivingthemstability。Thisforceheconceivedtobeexertedbytheexpansionofheatedmatter。

"Wehave，"hesaid，"beennowsupposingthatthebeginningofourpresentearthhadbeenlaidinthebottomoftheocean，atthecompletionoftheformerland，butthiswasonlyforthesakeofdistinctness。Thejustviewisthis，thatwhentheformerlandoftheglobehadbeencomplete，soastobegintowasteandbeimpairedbytheencroachmentofthesea，thepresentlandbegantoappearabovethesurfaceoftheocean。

Inthismannerwesupposeadueproportiontobealwayspreservedoflandandwateruponthesurfaceoftheglobe，forthepurposeofahabitableworldsuchasthiswhichwepossess。Wethusalsoallowtimeandopportunityforthetranslationofanimalsandplantstooccupytheearth。

"ButiftheearthonwhichwelivebegantoappearintheoceanatthetimewhentheLASTbegantoberesolved，itcouldnotbefromthematerialsofthecontinentimmediatelyprecedingthiswhichweexaminethatthepresentearthhasbeenconstructed；forthebottomoftheoceanmusthavebeenfilledwithmaterialsbeforelandcouldbemadetoappearaboveitssurface。

"LetussupposethatthecontinentwhichistosucceedourlandisatpresentbeginningtoappearabovethewaterinthemiddleofthePacificOcean；itmustbeevidentthatthematerialsofthisgreatbody，whichisformedandreadytobebroughtforth，musthavebeencollectedfromthedestructionofanearthwhichdoesnotnowappear。Consequently，inthistruestatementofthecasethereisnecessarilyrequiredthedestructionofananimalandvegetableearthpriortotheformerland；andthematerialsofthatearthwhichisfirstinouraccountmusthavebeencollectedatthebottomoftheocean，andbeguntobeconcoctedfortheproductionofthepresentearth，whenthelandimmediatelyprecedingthepresenthadarrivedatitsfullextent。

"Wehavenowgottotheendofourreasoning；wehavenodatafurthertoconcludeimmediatelyfromthatwhichactuallyis；butwehavegotenough；wehavethesatisfactiontofindthatinnaturetherearewisdom，system，andconsistency。Forhavinginthenaturalhistoryoftheearthseenasuccessionofworlds，wemayfromthisconcludethatthereisasysteminnature；inlikemanneras，fromseeingrevolutionsoftheplanets，itisconcludedthatthereisasystembywhichtheyareintendedtocontinuethoserevolutions。

Butifthesuccessionofworldsisestablishedinthesystemofnature，itisinvaintolookforanythinghigherintheoriginoftheearth。Theresult，therefore，ofourpresentinquiryisthatwefindnovestigeofabeginning——noprospectofanend。"

Altogetherremarkableasthispaperseemsinthelightoflaterknowledge，neitherfriendnorfoedeignedtonoticeitatthemoment。Itwasnotpublishedinbookformuntilthelastdecadeofthecentury，whenHuttonhadlivedwithandworkedoverhistheoryforalmostfiftyyears。Thenitcaughttheeyeoftheworld。AschooloffollowersexpoundedtheHuttoniandoctrines；arivalschoolunderWernerinGermanyopposedsomedetailsofthehypothesis，andtheeducatedworldasawholeviewedthedisputantsaskance。

Theverynoveltyofthenewviewsforbadetheirimmediateacceptance。Bitterattacksweremadeuponthe"heresies，"andthatwasmeanttobeasoberlytemperedjudgmentwhichin1800pronouncedHutton’stheories"notonlyhostiletosacredhistory，butequallyhostiletotheprinciplesofprobability，totheresultsoftheablestobservationsonthemineralkingdom，andtothedictatesofrationalphilosophy。"AndallthisbecauseHutton’stheorypresupposedtheearthtohavebeeninexistencemorethansixthousandyears。

Thusitappearsthatthoughthethoughtsofmenhadwidened，inthoseclosingdaysoftheeighteenthcentury，toincludethestars，theyhadnotasyetexpandedtoreceivethemostpatentrecordsthatarewritteneverywhereonthesurfaceoftheearth。BeforeHutton’sviewscouldbeaccepted，hispivotalconceptionthattimeislongmustbeestablishedbyconvincingproofs。TheevidencewasbeinggatheredbyWilliamSmith，Cuvier，andotherdevoteesofthebuddingscienceofpaleontologyinthelastdaysofthecentury，buttheirlaborswerenotbroughttocompletiontillasubsequentepoch。

NEPTUNISTSVERSUSPLUTONISTS

Inthemeantime，JamesHutton’stheorythatcontinentswearawayandarereplacedbyvolcanicupheavalgainedcomparativelyfewadherents。EventhelucidIllustrationsoftheHuttonianTheory，whichPlayfair，thepupilandfriendofthegreatScotchman，publishedin1802，didnotatonceproveconvincing。

TheworldhadbecomeenamouredoftherivaltheoryofHutton’sfamouscontemporary，WernerofSaxony——thetheorywhichtaughtthat"inthebeginning"allthesolidsoftheearth’spresentcrustweredissolvedintheheatedwatersofauniversalsea。Werneraffirmedthatallrocks，ofwhatevercharacter，hadbeenformedbyprecipitationfromthisseaasthewaterscooled；thatevenveinshaveoriginatedinthisway；

andthatmountainsaregiganticcrystals，notupheavedmasses。Inaword，hepracticallyignoredvolcanicaction，anddeniedintotothetheoryofmetamorphosisofrocksthroughtheagencyofheat。

ThefollowersofWernercametobeknownasNeptunists；

theHuttoniansasPlutonists。Thehistoryofgeologyduringthefirstquarterofthenineteenthcenturyismainlyarecitaloftheintemperatecontroversybetweentheseopposingschools；thoughitshouldnotbeforgottenthat，meantime，themembersoftheGeologicalSocietyofLondonweremakinganefforttohuntforfactsandavoidcompromisingtheories。Factandtheory，however，weretoocloselylinkedtobethusdivorced。

Thebruntofthecontroversysettledabouttheunstratifiedrocks——granitesandtheirallies——whichthePlutonistsclaimedasofigneousorigin。Thiscontentionhadthetheoreticalsupportofthenebularhypothesis，thengainingground，whichsupposedtheearthtobeacoolingglobe。ThePlutonistslaidgreatstress，too，ontheobservedfactthatthetemperatureoftheearthincreasesataprettyconstantratioasdescenttowardsitscentreismadeinmines。Butinparticulartheyappealedtothephenomenaofvolcanoes。

TheevidencefromthissourcewasgatheredandelaboratedbyMr。G。PoulettScrope，secretaryoftheGeologicalSocietyofEngland，who，in1823，publishedaclassicalworkonvolcanoesinwhichheclaimedthatvolcanicmountains，includingsomeofthehighest-

knownpeaks，aremerelyaccumulatedmassesoflavabelchedforthfromacreviceintheearth’scrust。

"Supposingtheglobetohavehadanyirregularshapewhendetachedfromthesun，"saidScrope，"thevaporizationofitssurface，and，ofcourse，ofitsprojectingangles，togetherwithitsrotatorymotiononitsaxisandtheliquefactionofitsouterenvelope，wouldnecessarilyoccasionitsactualfigureofanoblatespheroid。Astheprocessofexpansionproceededindepth，theoriginalgraniticbedswerefirstpartiallydisaggregated，nextdisintegrated，andmoreorlessliquefied，thecrystalsbeingmergedintheelasticvehicleproducedbythevaporizationofthewatercontainedbetweenthelaminae。

"Wherethisfluidwasproducedinabundancebygreatdilatation——thatis，intheouterandhighlydisintegratedstrata，thesuperiorspecificgravityofthecrystalsforcedittooozeupward，andthusagreatquantityofaqueousvaporwasproducedonthesurfaceoftheglobe。Asthiselasticfluidroseintoouterspace，itscontinuallyincreasingexpansionmusthaveproportionatelylowereditstemperature；and，inconsequence，apartwasrecondensedintowaterandsankbacktowardsthemoresolidsurfaceoftheglobe。

"Andinthismanner，foracertaintime，aviolentreciprocationofatmosphericphenomenamusthavecontinued——torrentsofvaporrisingoutwardly，whileequallytremendoustorrentsofcondensedvapor，orrain，felltowardstheearth。Theaccumulationofthelatterontheyetunstableandunconsolidatedsurfaceoftheglobeconstitutedtheprimevalocean。Thesurfaceofthisoceanwasexposedtocontinuedvaporizationowingtointenseheat；butthisprocess，abstractingcaloricfromthestratumofthewaterbelow，bypartiallycoolingit，tendedtopreservetheremainderinaliquidform。Theoceanwillhavecontained，bothinsolutionandsuspension，manyofthematterscarriedupwardfromthegraniticbedinwhichthevaporsfromwhosecondensationitproceededwereproduced，andwhichtheyhadtraversedintheirrise。Thedissolvedmatterswillhavebeensilex，carbonates，andsulphatesoflime，andthoseothermineralsubstanceswhichwateratanintensetemperatureandundersuchcircumstanceswasenabledtoholdinsolution。Thesuspendedsubstanceswillhavebeenallthelighterandfinerparticlesoftheupperbedswherethedisintegrationhadbeenextreme；andparticularlytheirmica，which，owingtothetenuityofitsplate-shapedcrystals，wouldbemostreadilycarriedupbytheascendingfluid，andwillhaveremainedlongestinsuspension。

"Butasthetorrentsofvapor，holdingthesevariousmattersinsolutionandsuspension，wereforcedupward，thegreaterpartofthedisintegratedcrystalsbydegreessubsided；thoseoffelsparandquartzfirst，themicabeing，asobservedabove，fromtheformofitsplates，ofpeculiarbuoyancy，andthereforeheldlongestinsuspension。

"Thecrystalsoffelsparandquartzastheysubsided，togetherwithasmallproportionofmica，wouldnaturallyarrangethemselvessoastohavetheirlongestdimensionsmoreorlessparalleltothesurfaceonwhichtheyrest；andthisparallelismwouldbesubsequentlyincreased，asweshallseehereafter，bythepressureofthesebedssustainedbetweentheweightofthesupportedcolumnofmatterandtheexpansiveforcebeneaththem。ThesebedsIconceive，whenconsolidated，toconstitutethegneissformation。

"Thefarthertheprocessofexpansionproceededindepth，themorewasthecolumnofliquidmatterlengthened，which，gravitatingtowardsthecentreoftheglobe，tendedtocheckanyfurtherexpansion。

Itis，therefore，obviousthataftertheglobesettledintoitsactualorbit，andthenceforwardlostlittleofitsenvelopingmatter，thewholeofwhichbeganfromthatmomenttogravitatetowardsitscentre，theprogressofexpansioninwardlywouldcontinuallyincreaseinrapidity；andamomentmusthaveatlengtharrivedhentheforcesofexpansionandrepressionhadreachedanequilibriumandtheprocesswasstoppedfromprogressingfartherinwardlybythegreatpressureofthegravitatingcolumnofliquid。

Thiscolumnmaybeconsideredasconsistingofdifferentstrata，thoughthepassagefromoneextremityofcompletesoliditytotheotherofcompleteexpansion，inreality，musthavebeenperfectlygradual。

Theloweststratum，immediatelyabovetheextremelimitofexpansion，willhavebeengranitebarelyDISAGGREGATED，andrenderedimperfectlyliquidbythepartialvaporizationofitscontainedwater。

"ThesecondstratumwasgraniteDISINTEGRATED；

aqueousvapor，havingbeenproducedinsuchabundanceastobeenabledtoriseupward，partiallydisintegratingthecrystalsoffelsparandmica，andsuperficiallydissolvingthoseofquartz。Thismasswouldreconsolidateintogranite，thoughofasmallergrainthantheprecedingrock。

"ThethirdstratumwassodisintegratedthatagreaterpartofthemicahadbeencarriedupbytheescapingvaporINSUSPENSION，andthatofquartzinsolution；thefelsparcrystals，withtheremainingquartzandmica，SUBSIDINGbytheirspecificgravityandarrangingthemselvesinhorizontalplanes。

"Theconsolidationofthisstratumproducedthegneissformation。

"Thefourthzonewillhavebeencomposedoftheoceanofturbidandheatedwater，holdingmica，etc。，insuspension，andquartz，carbonateoflime，etc。，insolution，andcontinuallytraversedbyreciprocatingbodiesofheatedwaterrisingfrombelow，andofcoldfluidsinkingfromthesurface，byreasonoftheirspecificgravities。

"Thedisturbancethusoccasionedwillhavelongretardedthedepositionofthesuspendedparticles。

Butthismustbydegreeshavetakenplace，thequartzgrainsandthelargerandcoarserplatesofmicasubsidingfirstandthefinestlast。

"Butthefragmentsofquartzandmicawerenotdepositedalone；agreatproportionofthequartzheldinSOLUTIONmusthavebeenprecipitatedatthesametimeasthewatercooled，andthereforebydegreeslostitsfacultyofsomuchinsolution。Thuswasgraduallyproducedtheformationofmica-schist，themicaimperfectlyrecrystallizingorbeingmerelyaggregatedtogetherinhorizontalplates，betweenwhichthequartzeitherspreaditselfgenerallyinminutegrainsorunifiedintocrystallinenuclei。Onotherspots，insteadofsilex，carbonateoflimewasprecipitated，togetherwithmoreorlessofthenucaceoussediment，andgaverisetosaccharoidallimestones。Atalaterperiod，whentheoceanwasyetfurthercooleddown，rock-saltandsulphateoflimewerelocallyprecipitatedinasimilarmode。

"Thefifthstratumwasaeriform，andconsistedingreatpartofaqueousvapors；theremainderbeingacompoundofotherelasticfluids(permanentgases)

whichhadbeenformedprobablyfromthevolatilizationofsomeofthesubstancescontainedintheprimitivegraniteandcarriedupwardwiththeaqueousvaporfrombelow。Thesegaseswillhavebeeneithermixedtogetherorotherwisedisposed，accordingtotheirdifferentspecificgravitiesorchemicalaffinities，andthisstratumconstitutedtheatmosphereoraerialenvelopeoftheglobe。

"When，inthismanner，thegeneralandpositiveexpansionoftheglobe，occasionedbythesuddenreductionofoutwardpressure，hadceased(inconsequenceoftheREPRESSIVEFORCE，consistingoftheweightofitsfluidenvelope，havingreachedanequilibriumwiththeEXPANSIVEFORCE，consistingofthecaloricoftheheatednucleus)，therapidsuperficialevaporationoftheoceancontinued；and，bygraduallyreducingitstemperature，occasionedtheprecipitationofaproportionatequantityofthemineralsitheldinsolution，particularlyitssilex。Thesesubstancesfallingtothebottom，accompaniedbyalargeproportionofthemattersheldinsolution，particularlythemica，inconsequenceofthegreatercomparativetranquillityoftheocean，agglomeratedtheseintomoreorlesscompactbedsofrock(themica-schistformation)，producingthefirstcrustorsolidenvelopeoftheglobe。Uponthis，otherstratifiedrocks，composedsometimesofamixture，sometimesofanalternationofprecipitations，sediments，andoccasionallyofconglomerates，werebydegreesdeposited，givingrisetotheTRANSITIONformations。

"Beneaththiscrustanewprocessnowcommenced。

Theouterzonesofcrystallinematterhavingbeensuddenlyrefrigeratedbytherapidvaporizationandpartialescapeofthewatertheycontained，abstractedcaloricfromtheintenselyheatednucleusoftheglobe。

Thesecrystallinezoneswereofunequaldensity，theexpansiontheyhadsuffereddiminishingfromabovedownward。

"Theirexpansiveforcewas，however，equalatallpoints，theirtemperatureeverywherebearinganinverseratiototheirdensity。Butwhenbytheaccessionofcaloricfromtheinnerandunliquefiednucleusthetemperature，andconsequentlytheexpansiveforceofthelowerstrataofdilatedcrystallinematter，wasaugmented，itactedupontheupperandmoreliquefiedstrata。ThesebeingpreventedfromyieldingOUTWARDLYbythetenacityandweightofthesolidinvolucrumofprecipitatedandsedimentaldepositswhichoverspreadthem，sustainedapressureoutofproportiontotheirexpansiveforce，andwereinconsequenceproportionatelycondensed，andbythecontinuanceoftheprocess，wheretheoverlyingstrataweresufficientlyresistant，finallyconsolidated。

"Thisprocessofconsolidationmusthaveprogressedfromabovedownward，withtheincreaseoftheexpansiveforceinthelowerstrata，commencingfromtheuppersurface，which，itstemperaturebeinglowest，offeredtheleastresistancetotheforceofcompression。

"Bythisprocesstheupperzoneofcrystallinematter，whichhadintumescedsofarastoallowoftheescapeofitsaqueousvaporandofmuchofitsmicaandquartz，wasresolidified，thecomponentcrystalsarrangingthemselvesinplanesperpendiculartothedirectionofthepressurebywhichthemasswasconsolidated——thatis，totheradiusoftheglobe。

Thegneissformation，asalreadyobserved，wastheresult。

"Theinferiorzoneofbarelydisintegratedgranite，fromwhichonlyapartofthesteamandquartzandnoneofthemicahadescaped，reconsolidatedinaconfusedorgranitoidalmanner；butexhibitsmarksoftheprocessithadundergoneinitsbrokencrystalsoffelsparandmica，itsroundedandsuperficiallydissolvedgrainsofquartz，itsimbeddedfragments(brokenfromthemoresolidpartsofthemass，asitrose，andenvelopedbythesofterparts)，itsconcretionarynodulesandnewminerals，etc。

"Beneaththis，thegranitewhichhadbeensimplydisintegratedwasagainsolidified，andreturnedinallrespectstoitsformercondition。Thetemperature，however，andwithittheexpansiveforceoftheinferiorzone，wascontinuallyontheincrease，thecaloricoftheinterioroftheglobestillendeavoringtoputitselfinequilibriobypassingofftowardstheless-intenselyheatedcrust。

"Thiscontinuallyincreasingexpansiveforcemustatlengthhaveovercometheresistanceopposedbythetenacityandweightoftheoverlyingconsolidatedstrata。Itisreasonabletosupposethatthisresulttookplacecontemporaneously，ornearlyso，onmanyspots，whereveraccidentalcircumstancesinthetextureorcompositionoftheoceanicdepositsledthemtoyieldmorereadily；andinthismannerwereproducedthoseoriginalfissuresintheprimevalcrustoftheearththroughsomeofwhich(fissuresofelevation)wereintrudedportionsofinteriorcrystallinezonesinasolidornearlysolidstate，togetherwithmoreorlessoftheintumescentgranite，inthemannerabovedescribed；

whileothers(fissuresoferuption)gaverisetoextravasationsoftheheatedcrystallinematter，intheformoflavas——thatis，stillfurtherliquefiedbythegreatercomparativereductionofthepressuretheyendured。"[3]

TheNeptunistsstoutlycontendedfortheaqueousoriginofvolcanicasofothermountains。ButthefactswerewithScrope，andastimewentonitcametobeadmittedthatnotmerelyvolcanoes，butmany"trap"formationsnottakingtheformofcraters，hadbeenmadebytheobtrusionofmoltenrockthroughfissuresinoverlyingstrata。Such，forexample，tocitefamiliarillustrations，areMountHolyoke，inMassachusetts，andthewell-knownformationofthePalisadesalongtheHudson。

Buttoadmitthe"Plutonic"originofsuchwidespreadformationswaspracticallytoabandontheNeptunianhypothesis。SograduallytheHuttonianexplanationoftheoriginofgranitesandother"igneous"

rocks，whethermassedorinveins，cametobeaccepted。

Mostgeologiststhencametothinkoftheearthasamoltenmass，onwhichthecrustrestsasamerefilm。

Some，indeed，withLyell，preferredtobelievethatthemoltenareasexistonlyaslakesinasolidcrust，heatedtomelting，perhaps，byelectricalorchemicalaction，asDavysuggested。Morerecentlyapopulartheoryattemptstoreconcilegeologicalfactswiththeclaimofthephysicists，thattheearth’sentiremassisatleastasrigidassteel，bysupposingthatamoltenfilmrestsbetweentheobservedsolidcrustandtheallegedsolidnucleus。Butbethatasitmay，thetheorythatsubterraneanheathasbeeninstrumentalindeterminingtheconditionof"primary"rocks，andinproducingmanyotherphenomenaoftheearth’scrust，hasneverbeenindisputesincethelongcontroversybetweentheNeptunistsandthePlutonistsledtoitsestablishment。

LYELLANDUNIFORMITARIANISM

Ifmoltenmatterexistsbeneaththecrustoftheearth，itmustcontractincooling，andinsodoingitmustdisturbtheleveloftheportionofthecrustalreadysolidified。SoaplausibleexplanationoftheupheavalofcontinentsandmountainswassuppliedbythePlutoniantheory，asHuttonhadfromthefirstalleged。Butnowanimportantdifferenceofopinionaroseastotheexactrationaleofsuchupheavals。

Huttonhimself，andpracticallyeveryoneelsewhoacceptedhistheory，hadsupposedthattherearelongperiodsofrelativerepose，duringwhichthelevelofthecrustisundisturbed，followedbyshortperiodsofactivestress，whencontinentsarethrownupwithvolcanicsuddenness，asbythethroesofagiganticearthquake。

ButnowcameCharlesLyellwithhisfamousextensionofthe"uniformitarian"doctrine，claimingthatpastchangesoftheearth’ssurfacehavebeenlikepresentchangesindegreeaswellasinkind。Themakingofcontinentsandmountains，hesaid，isgoingonasrapidlyto-dayasatanytimeinthepast。Therehavebeennogiganticcataclysmicupheavalsatanytime，butallchangesinlevelofthestrataasawholehavebeengradual，byslowoscillation，oratmostbyrepeatedearthquakeshockssuchasarestilloftenexperienced。

InsupportofthisverystartlingcontentionLyellgatheredamassofevidenceoftherecentchangesinlevelofcontinentalareas。HecorroboratedbypersonalinspectiontheclaimwhichhadbeenmadebyPlayfairin1802，andbyVonBuchin1807，thatthecoast-lineofSwedenisrisingattherateoffromafewinchestoseveralfeetinacentury。HecitedDarwin’sobservationsgoingtoprovethatPatagoniaissimilarlyrising，andPingel’sclaimthatGreenlandisslowlysinking。

Proofastosuddenchangesoflevelofseveralfeet，overlargeareas，duetoearthquakes，wasbroughtforwardinabundance。Cumulativeevidenceleftitnolongeropentoquestionthatsuchoscillatorychangesoflevel，eitherupwardordownward，arequitetherule，anditcouldnotbedeniedthattheseobservedchanges，ifcontinuedlongenoughinonedirection，wouldproducethehighestelevations。Thepossibilitythatthemakingofeventhehighestrangesofmountainshadbeenaccomplishedwithoutexaggeratedcatastrophicactioncametobefreelyadmitted。

Itbecameclearthatthesupposedlystable-landsurfacesareinrealitymuchmorevariablethanthesurfaceofthe"shiftingsea"；thatcontinentalmasses，seeminglysofixed，arereallyrisingandfallinginbillowsthousandsoffeetinheight，agesinsteadofmomentsbeingconsumedinthesweepbetweencrestandhollow。

Theseslowoscillationsoflandsurfacesbeingunderstood，manygeologicalenigmasweremadeclear——

suchasthealternationofmarineandfresh-waterformationsinaverticalseries，whichCuvierandBrongniarthadobservednearParis；orthesandwichingoflayersofcoal，ofsubaerialformation，betweenlayersofsubaqueousclayorsandstone，whichmaybeobservedeverywhereinthecoalmeasures。Inparticular，theextremethicknessofthesedimentarystrataasawhole，manytimesexceedingthedepthofthedeepestknownsea，wasforthefirsttimeexplicablewhenitwasunderstoodthatsuchstratahadformedinslowlysinkingocean-beds。

Alldoubtastothemodeoforiginofstratifiedrocksbeingthusremoved，thewaywasopenedforamorefavorableconsiderationofthatotherHuttoniandoctrineoftheextremelyslowdenudationoflandsurfaces。

Theenormousamountoflanderosionwillbepatenttoanyonewhouseshiseyesintelligentlyinamountaindistrict。Itwillbeevidentinanyregionwherethestrataaretilted——as，forexample，theAlleghanies——

thatgreatfoldsofstratawhichmustoncehaverisenmilesinheighthaveinmanycasesbeenwornentirelyaway，sothatnowavalleymarksthelocationoftheformereminence。Wherethestrataarelevel，asinthecaseofthemountainsofSicily，theScotchHighlands，andthefamiliarCatskills，theevidenceofdenudationis，ifpossible，evenmoremarked；forhereitisclearthatelevationandvalleyhavebeencarvedbytheelementsoutoflandthatrosefromtheseaaslevelplateaus。

Butthatthisherculeanlaborofland-sculpturingcouldhavebeenaccomplishedbytheslowactionofwindandfrostandshowerwasanideafewmencouldgraspwithinthefirsthalf-centuryafterHuttonpropoundedit；nordiditbegintogaingeneralcurrencyuntilLyell’scrusadeagainstcatastrophism，begunabout1830，hadforaquarterofacenturyaccustomedgeologiststothethoughtofslow，continuouschangesproducingfinalresultsofcolossalproportions。AndevenlongafterthatitwascombatedbysuchmenasMurchison，Director-GeneraloftheGeologicalSurveyofGreatBritain，thenaccountedtheforemostfield-geologistofhistime，whocontinuedtobelievethattheexistingvalleysowetheirmainfeaturestosubterraneanforcesofupheaval。EvenMurchison，however，madesomerecessionfromthebeliefoftheContinentalauthorities，EliedeBeaumontandLeopoldvonBuch，whocontendedthatthemountainshadsprunguplikeveritablejacks-in-the-box。VonBuch，whomhisfriendandfellow-pupilVonHumboldtconsideredtheforemostgeologistofthetime，diedin1853，stillfirminhisearlyfaiththattheerraticbowldersfoundhighontheJurahadbeenhurledthere，likecannon-balls，acrossthevalleyofGenevabythesuddenupheavalofaneighboringmountain-range。