Researchwasnowredoubled，and，asaresult，humanskullsandcompleteskeletonsofvarioustypesbegantobediscoveredintheancientdepositsofmanyotherpartsoftheworld，andespeciallyinFrance，Belgium，Germany，theCaucasus，Africa，andNorthandSouthAmerica。
Butsoonbegantoemergefromallthesediscoveriesafactofenormousimportance。TheskullsandbonesfoundatCroMagnon，Solutre，Furfooz，Grenelle，andelsewhere，werecompared，anditwasthusmadecertainthatvariousraceshadalreadyappearedandlivedinvariousgradesofcivilization，eveninthoseexceedinglyremoteepochs；thateventhentherewerevariousstrataofhumanityrangingfromracesofaverylowtothoseofaveryhightype；andthatuponanytheory——certainlyuponthetheoryoftheoriginofmankindfromasinglepair——twothingswereevident：first，thatlong，slowprocessesduringvastperiodsoftimemusthavebeenrequiredforthedifferentiationoftheseraces，andfortheevolutionofmanuptothepointwherethebetterspecimensshowhim，certainlyintheearlyQuaternaryandperhapsintheTertiaryperiod；and，secondly，thattherehadbeenfromthefirstappearanceofman，ofwhichwehaveanytraces，anUPWARDtendency。[191]
[191]ForWesley’sstatementoftheamazingconsequencesoftheentranceofdeathintotheworldbysin，seecitationsinhissermononTheFallofManinthechapteronGeology。ForBoucherdePerthes，seehisLifebyLedieu，especiallychaptersvandxix；alsolettersintheappendix；alsoLesAntiquitiesCeltiquesetAntediluviennes，ascitedinpreviouschaptersofthiswork。
ForanaccountoftheNeanderthalmanandotherremainsmentioned，seeQuatrefages，HumanSpecies，chap。xxvi；alsoMortillet，LePrehistorique，Paris，1885，pp。232etseq。；alsootherwriterscitedinthischapter。Fortheotherdiscoveriesmentioned，seethesamesources。ForanengravingoftheskullandtherestoredhumanfaceoftheNeanderthalman，seeReinach，AntiquitiesNationales，etc。，vol。i，p。138。Forthevastregionsoverwhichthatearlyracespread，seeQuatrefagesasabove，p。307。Seealsothesameauthor，HistoireGeneraledesRacesHumaines，intheBibliothequeEthnologique，Paris，1887，p。
4。Inthevastmassofliteraturebearingonthissubject，seeQuatrefages，Dupont，Reinach，Joly，Mortillet，Tylor，andLubbock，inworkscitedthroughthesechapters。
Thissecondconclusion，theupwardtendencyofmanfromlowbeginnings，wasmademoreandmoreclearbybringingintorelationswiththeseremainsofhumanbodiesandofextinctanimalstheremainsofhumanhandiwork。Asstatedinthelastchapter，theriverdriftandbonecavesinGreatBritain，France，andotherpartsoftheworld，revealedaprogression，eveninthevariousdivisionsoftheearliestStoneperiod；for，beginningattheveryloweststrataoftheseremains，onthefloorsofthecaverns，associatedmainlywiththebonesofextinctanimals，suchasthecavebear，thehairyelephant，andthelike，weretherudestimplementsthen，instrataabovethese，sealedinthestalagmiteofthecavernfloors，lyingwiththebonesofanimalsextinctbutmorerecent，stoneimplementswerefound，stillrude，but，asarule，ofanimprovedtype；and，finally，inastillhigherstratum，associatedwithbonesofanimalslikethereindeerandbison，which，thoughnotextinct，havedepartedtootherclimates，wererudestoneimplements，onthewholeofastillbetterworkmanship。Suchwastheforeshadowing，evenatthatearlyrudeStoneperiod，oftheproofsthatthetendencyofmanhasbeenfromhisearliestepochandinallpartsoftheworld，asarule，upward。
Butthisrulewastobemuchfurtherexemplified。About1850，whiletheFrenchandEnglishgeologistswereworkingmoreespeciallyamongtherelicsofthedriftandcaveperiods，notedarchaeologistsoftheNorth——Forchammer，Steenstrup，andWorsaae——weredevotingthemselvestotheinvestigationofcertainremainsupontheDanishPeninsula。Theseremainswereoftwokinds：first，therewerevastshell-heapsoraccumulationsofshellsandotherrefusecastasidebyrudetribeswhichatsomeunknownageinthepastlivedontheshoresoftheBaltic，principallyonshellfish。Thattheseshell-heapswereveryancientwasevident：theshellsofoystersandthelikefoundinthemwerefarlargerthananynowfoundonthosecoasts；theirsize，sofarfrombeinglikethatofthecorrespondingvarietieswhichnowexistinthebrackishwatersoftheBaltic，wasineverycaselikethatofthosevarietieswhichonlythriveinthewatersoftheopensaltsea。Herewasaclearindicationthatatthetimewhenmanformedtheseshell-heapsthosecoastswereinfarmoredirectcommunicationwiththesaltseathanatpresent，andthatsufficienttimemusthaveelapsedsincethatperiodtohavewroughtenormouschangesinseaandlandthroughoutthoseregions。
Scatteredthroughtheseheapswerefoundindicationsofagradeofcivilizationwhenmanstillusedimplementsofstone，butimplementsandweaponswhich，thoughstillrude，showedaprogressfromthoseofthedriftandearlycaveperiod，someofthembeingofpolishedstone。
Withthesewereotherevidencesthatcivilizationhadprogressed。
Withimplementsrudeenoughtohavesurvivedfromearlyperiods，otherimplementsneverknowninthedriftandbonecavesbegantoappear，and，thoughtherewerefewifanybonesofotherdomesticanimals，theremainsofdogswerefound；everythingshowedthattherehadbeenaprogressincivilizationbetweentheformerStoneepochandthis。
ThesecondseriesofdiscoveriesinScandinaviawasmadeinthepeat-beds：theseweregenerallyformedinhollowsorbowlsvaryingindepthfromtentothirtyfeet，andasectionofthem，likeasectionofthedepositsinthebonecaverns，showedagradualevolutionofhumanculture。Thelowerstratainthesegreatbowlswerefoundtobemadeupchieflyofmossesandvariousplantsmattedtogetherwiththetrunksoffallentrees，sometimesofverylargediameter；andthebotanicalexaminationofthelowestlayerofthesetreesandplantsinthevariousbowlsrevealedamostimportantfact：forthislayer，thefirstinpointoftime，wasalwaysoftheScotchfir——whichnowgrowsnowhereintheDanishislands，andcannotbemadetogrowanywhereinthem——andofplantswhicharenowextinctintheseregions，buthaveretreatedwithinthearcticcircle。Comingupfromthebottomofthesegreatbowlstherewasfoundabovethefirstlayerasecond，inwhichweremattedtogethermassesofoaktreesofdifferentvarieties；these，too，wererelicsofabygoneepoch，sincetheoakhasalmostentirelydisappearedfromDenmark。Abovethesecameathirdstratummadeupoffallenbeechtrees；andthebeechisnow，andhasbeensincethebeginningofrecordedhistory，themostcommontreeoftheDanishPeninsula。
Nowcameasecondfactoftheutmostimportanceasconnectedwiththefirst。Scattered，asarule，throughthelowerofthesedeposits，thatoftheextinctfirtreesandplants，werefoundimplementsandweaponsofsmoothstone；inthelayerofoaktreeswerefoundimplementsofbronze；andamongthelayerofbeecheswerefoundimplementsandweaponsofiron。
Thegeneralresultoftheseinvestigationsinthesetwosources，theshellmoundsandthepeatdeposits，wasthesame：thefirstcivilizationevidencedinthemwasmarkedbytheuseofstoneimplementsmoreorlesssmooth，showingaprogressfromtheearlierrudeStoneperiodmadeknownbythebonecaves；thencamealaterprogresstoahighercivilization，markedbytheuseofbronzeimplements；and，finally，astillhigherdevelopmentwhenironbegantobeused。
ThelaboursoftheDanisharchaeologistshaveresultedintheformationofagreatmuseumatCopenhagen，andonthespecimenstheyhavefound，coupledwiththoseofthedriftandbonecaves，isbasedtheclassificationbetweenthemainperiodsordivisionsintheevolutionofthehumanraceabovereferredto。
ItwasnotmerelyinScandinavianlandsthattheseresultswerereached；substantiallythesamediscoveriesweremadeinIrelandandFrance，inSardiniaandPortugal，inJapanandinBrazil，inCubaandintheUnitedStates；infact，asarule，innearlyeverypartoftheworldwhichwasthoroughlyexamined。[192]
[192]Forthegeneralsubject，seeMortillet，LePrehistorique，p。498，etpassim。Forexamplesoftherudestoneimplements，improvingaswegofromearliertolaterlayersinthebonecaves，seeBoydHawkins，EarlyManinBritain，chap。vii，p。186；
alsoQuatrefages，HumanSpecies，NewYork，1879，pp。305etseq。
AninterestinggleamoflightisthrownonthesubjectinDeBaye，GrottesPrehistoriquesdelaMarne，pp。31etseq。；alsoEvans，ascitedinthepreviouschapter。ForthemorerecentinvestigationsintheDanishshell-heaps，seeBoydDawkins，EarlyManinBritain，pp。303，304。Fortheseevidencesofadvancedcivilizationintheshell-heaps，seeMortillet，p。498。He，likeNilsson，saysthatonlythebonesofthedogwerefound；butcompareDawkins，p。305。Fortheveryfulllistofthesediscoveries，withtheirbearingoneachother，seeMortillet，p。
499。AstothoseinScandanaviancountries，seeNilsson，ThePrimitiveInhabitantsofScandanavia，thirdedition，withIntroductionbyLubbock，London，1868；alsothePre-HistoryoftheNorth，byWorsaae，Englishtranslation，London，1886。Forshell-moundsandtheircontentsintheSpanishPeninsula，seeCartailhac’sgreaterworkalreadycited。Forsummaryofsuchdiscoveriesthroughouttheworld，seeMortillet，LePrehistorique，pp。497etseq。
Butfromanotherquartercameayetmorestrikingindicationofthissameevolution。Asfarbackastheyear1829therewerediscovered，intheLakeofZurich，pilesandotherantiquitiesindicatingaformerexistenceofhumandwellings，standinginthewateratsomedistancefromtheshore；buttheusualmixtureofthoughtlessnessanddreadofnewideasseemstohaveprevailed，andnothingwasdoneuntilabout1853，whennewdiscoveriesofthesamekindwerefollowedupvigorously，andRutimeyer，Keller，Troyon，andothersshowednotonlyintheLakeofZurich，butinmanyotherlakesinSwitzerland，remainsofformerhabitations，and，inthemidstofthese，greatnumbersofrelics，exhibitingthegradeofcivilizationwhichthoselakedwellershadattained。
Here，too，wereaccumulatedproofsoftheupwardtendencyofthehumanrace。Implementsofpolishedstone，bone，leather，potteryofvariousgrades，wovencloth，bonesofseveralkindsofdomesticanimals，varioussortsofgrain，breadwhichhadbeenpreservedbycharring，andamultitudeofevidencesofprogressneverfoundamongtheearlier，ruderrelicsofcivilization，showedyetmorestronglythatmanhadarrivedhereatastillhigherstagethanhispredecessorofthedrift，cave，andshell-heapperiods，andhadgoneonfrombettertobetter。
Verystrikingevidencesofthisupwardtendencywerefoundineachclassofimplements。Asbycomparingthechippedflintimplementsofthelowerandearlierstratainthecaveperiodwiththoseofthelaterandupperstratawesawprogress，so，ineachoftheperiodsofpolishedstone，bronze，andiron，wesee，bysimilarcomparisons，asteadyprogressfromrudetoperfectedimplements；andespeciallyisthistrueintheremainsofthevariouslake-dwellings，foramongthesecanbetracedoutconstantincreaseinthevarietyofanimalsdomesticated，andgradualimprovementsinmeansofsubsistenceandinwaysofliving。
Incidentally，too，afact，atfirstsightofsmallaccount，butonreflectionexceedinglyimportant，wasrevealed。Theearlierbronzeimplementswerefrequentlyfoundtoimitateinvariousminorrespectsimplementsofstone；inotherwords，formswereatfirstgiventobronzeimplementsnaturalinworkingstone，butnotnaturalinworkingbronze。ThisshowedtheDIRECTIONofthedevelopment——thatitwasupwardfromstonetobronze，notdownwardfrombronzetostone；thatitwasprogressratherthandecline。
Theseinvestigationsweresupplementedbysimilarresearcheselsewhere。Inmanyotherpartsoftheworlditwasfoundthatlake-dwellershadexistedindifferentgradesofcivilization，butallwithinacertainrange，intermediatebetweenthecave-dwellersandthehistoricperiod。Toexplainthisepochofthelake-dwellers，historycameinwiththeaccountgivenbyHerodotusofthelake-dwellingsonLakePrasias，whichgaveprotectionfromthearmiesofPersia。Stillmoreimportant，ComparativeEthnographyshowedthatto-day，invariouspartsoftheworld，especiallyinNewGuineaandWestAfrica，racesofmenarelivinginlake-dwellingsbuiltuponpiles，andwitharangeofimplementsandweaponsstrikinglylikemanyofthosediscoveredintheseancientlakedepositsofSwitzerland。
InGreatBritain，France，Germany，Italy，Ireland，Scotland，andothercountries，remainsofadifferentsortwerealsofound，throwinglightonthisprogress。Thecromlechs，cranogs，mounds，andthelike，thoughsomeofthemindicatetheworkofweakertribespresseduponbystronger，show，asarule，thesameupwardtendency。
Ataveryearlyperiodinthehistoryofthesediscoveries，variousattemptsweremade——nominallyintheinterestofreligion，butreallyintheinterestofsundrycreedsandcatechismsframedwhenmenknewlittleornothingofnaturallaws——tobreaktheforceofsuchevidencesoftheprogressanddevelopmentofthehumanracefromlowertohigher。Outofalltheearliereffortstwomaybetakenasfairlytypical，fortheyexhibittheoppositiontoscienceasdevelopedundertwodifferentschoolsoftheology，eachworkinginitsownway。Thefirstoftheseshowsgreatingenuityandlearning，andispresentedbyMr。Southallinhisbook，publishedin1875，entitledTheRecentOriginoftheWorld。InthishegrapplesfirstofallwiththedifficultiespresentedbytheearlydateofEgyptiancivilization，andthekeynoteofhisargumentisthestatementmadebyaneminentEgyptologist，ataperiodbeforemodernarchaeologicaldiscoverieswerewellunderstood，that“EgyptlaughstheideaofarudeStoneage，apolishedStoneage，aBronzeage，anIronage，toscorn。”