Thepulpymatteroftheinternalcoatingsuddenlygroupeditselfintolines，someofwhichassumedaformradiatingfromacommoncentre；itthencontinued，withanirregularandrapidmovement，tocontractitself，sothatinthecourseofasecondthewholewasunitedintoaperfectlittlesphere，whichoccupiedthepositionoftheseptumatoneendofthenowquitehollowcase。Theformationofthegranularspherewashastenedbyanyaccidentalinjury。Imayadd，thatfrequentlyapairofthesebodieswereattachedtoeachother，asrepresentedabove，conebesidecone，atthatendwheretheseptumoccurs。
　　Iwilladdhereafewotherobservationsconnectedwiththediscolorationoftheseafromorganiccauses。OnthecoastofChile，afewleaguesnorthofConcepcion，theBeagleonedaypassedthroughgreatbandsofmuddywater，exactlylikethatofaswollenriver；andagain，adegreesouthofValparaiso，whenfiftymilesfromtheland，thesameappearancewasstillmoreextensive。
　　Someofthewaterplacedinaglasswasofapalereddishtint；and，examinedunderamicroscope，wasseentoswarmwithminuteanimalculadartingabout，andoftenexploding。Theirshapeisoval，andcontractedinthemiddlebyaringofvibratingcurvedciliae。Itwas，however，verydifficulttoexaminethemwithcare，foralmosttheinstantmotionceased，evenwhilecrossingthefieldofvision，theirbodiesburst。Sometimesbothendsburstatonce，sometimesonlyone，andaquantityofcoarse，brownish，granularmatterwasejected。Theanimalaninstantbeforeburstingexpandedtohalfagainitsnaturalsize；andtheexplosiontookplaceaboutfifteensecondsaftertherapidprogressivemotionhadceased：inafewcasesitwasprecededforashortintervalbyarotatorymovementonthelongeraxis。Abouttwominutesafteranynumberwereisolatedinadropofwater，theythusperished。
　　Theanimalsmovewiththenarrowapexforwards，bytheaidoftheirvibratoryciliae，andgenerallybyrapidstarts。Theyareexceedinglyminute，andquiteinvisibletothenakedeye，onlycoveringaspaceequaltothesquareofthethousandthofaninch。Theirnumberswereinfinite；forthesmallestdropofwaterwhichIcouldremovecontainedverymany。Inonedaywepassedthroughtwospacesofwaterthusstained，oneofwhichalonemusthaveextendedoverseveralsquaremiles。Whatincalculablenumbersofthesemicroscopicalanimals！Thecolourofthewater，asseenatsomedistance，waslikethatofariverwhichhasflowedthrougharedclaydistrict，butundertheshadeofthevessel’ssideitwasquiteasdarkaschocolate。
　　Thelinewheretheredandbluewaterjoinedwasdistinctlydefined。Theweatherforsomedayspreviouslyhadbeencalm，andtheoceanabounded，toanunusualdegree，withlivingcreatures[note9]。
　　IntheseaaroundTierradelFuego，andatnogreatdistancefromtheland，Ihaveseennarrowlinesofwaterofabrightredcolour，fromthenumberofcrustacea，whichsomewhatresembleinformlargeprawns。Thesealerscallthemwhale-food。WhetherwhalesfeedonthemIdonotknow；
　　butterns，cormorants，andimmenseherdsofgreatunwieldysealsderive，onsomepartsofthecoast，theirchiefsustenancefromtheseswimmingcrabs。Seameninvariablyattributethediscolorationofthewatertospawn；
　　butIfoundthistobethecaseonlyononeoccasion。AtthedistanceofseveralleaguesfromtheArchipelagooftheGalapagos，theshipsailedthroughthreestripsofadarkyellowish，ormudlikewater；thesestripsweresomemileslong，butonlyafewyardswide，andtheywereseparatedfromthesurroundingwaterbyasinuousyetdistinctmargin。Thecolourwascausedbylittlegelatinousballs，aboutthefifthofaninchindiameter，inwhichnumerousminutesphericalovuleswereimbedded：theywereoftwodistinctkinds，onebeingofareddishcolourandofadifferentshapefromtheother。Icannotformaconjectureastowhattwokindsofanimalsthesebelonged。CaptainColnettremarks，thatthisappearanceisverycommonamongtheGalapagosIslands，andthatthedirectionsofthebandsindicatethatofthecurrents；inthedescribedcase，however，thelinewascausedbythewind。TheonlyotherappearancewhichIhavetonotice，isathinoilycoatonthewaterwhichdisplaysiridescentcolours。IsawaconsiderabletractoftheoceanthuscoveredonthecoastofBrazil；theseamenattributedittotheputrefyingcarcaseofsomewhale，whichprobablywasfloatingatnogreatdistance。Idonotherementiontheminutegelatinousparticles，hereaftertobereferredto，whicharefrequentlydispersedthroughoutthewater，fortheyarenotsufficientlyabundanttocreateanychangeofcolour。
　　Therearetwocircumstancesintheaboveaccountswhichappearremarkable：
　　first，howdothevariousbodieswhichformthebandswithdefinededgeskeeptogether？Inthecaseoftheprawn-likecrabs，theirmovementswereascoinstantaneousasinaregimentofsoldiers；butthiscannothappenfromanythinglikevoluntaryactionwiththeovules，ortheconfervae，norisitprobableamongtheinfusoria。Secondly，whatcausesthelengthandnarrownessofthebands？Theappearancesomuchresemblesthatwhichmaybeseenineverytorrent，wherethestreamuncoilsintolongstreaksthefrothcollectedintheeddies，thatImustattributetheeffecttoasimilaractioneitherofthecurrentsoftheairorsea。Underthissuppositionwemustbelievethatthevariousorganizedbodiesareproducedincertainfavourableplaces，andarethenceremovedbythesetofeitherwindorwater。Iconfess，however，thereisaverygreatdifficultyinimagininganyonespottobethebirthplaceofthemillionsofmillionsofanimalculaandconfervae：forwhencecomethegermsatsuchpoints？——theparentbodieshavingbeendistributedbythewindsandwavesovertheimmenseocean。ButonnootherhypothesiscanIunderstandtheirlineargrouping。
　　ImayaddthatScoresbyremarksthatgreenwateraboundingwithpelagicanimalsisinvariablyfoundinacertainpartoftheArcticSea。Notes：IstatethisontheauthorityofDr。E。Dieffenbach，inhisGermantranslationofthefirsteditionofthisJournal。TheCapedeVerdIslandswerediscoveredin1449。Therewasatombstoneofabishopwiththedateof1571；andacrestofahandanddagger，dated1497。Imusttakethisopportunityofacknowledgingthegreatkindnesswithwhichthisillustriousnaturalisthasexaminedmanyofmyspecimens。IhavesentJune，1845afullaccountofthefallingofthisdusttotheGeologicalSociety。SonamedaccordingtoPatrickSymes’snomenclature。SeeEncyclop。ofAnat。andPhysiol。，articleCephalopodaMr。HornerandSirDavidBrewsterhavedescribedPhilosophicalTransactions，1836，p。65asingular“artificialsubstanceresemblingshell。”Itisdepositedinfine，transparent，highlypolished，brown-colouredlaminae，possessingpeculiaropticalproperties，ontheinsideofavessel，inwhichcloth，firstpreparedwithglueandthenwithlime，ismadetorevolverapidlyinwater。Itismuchsofter，moretransparent，andcontainsmoreanimalmatter，thanthenaturalincrustationatAscension；butwehereagainseethestrongtendencywhichcarbonateoflimeandanimalmatterevincetoformasolidsubstancealliedtoshell。Pers。Narr。，vol。v。，pt。1。，p。18。M。Montagne，inComptesRendus，etc。，Juillet，1844；
　　andAnnal。desScienc。Nat。，Dec。1844M。LessonVoyagedelaCoquille，tom。i。，p。255
　　mentionsredwateroffLima，apparentlyproducedbythesamecause。Peron，thedistinguishednaturalist，intheVoyageauxTerresAustrales，givesnolessthantwelvereferencestovoyagerswhohavealludedtothediscolouredwatersoftheseavol。ii。p。239。TothereferencesgivenbyPeronmaybeadded，Humboldt’sPers。Narr。，vol。vi。p。804；Flinder’sVoyage，vol。
　　i。p。92；Labillardiere，vol。i。p。287；Ulloa’sVoyage；VoyageoftheAstrolabeandoftheCoquille；CaptainKing’sSurveyofAustralia，etc。NextChapterTheVoyageoftheBeagle-Chapter2TheVoyageoftheBeaglebyCharlesDarwinPreviousChapterNextChapterChapter2-RiodeJaneiroAPRIL4thtoJuly5th，1832——AfewdaysafterourarrivalIbecameacquaintedwithanEnglishmanwhowasgoingtovisithisestate，situatedrathermorethanahundredmilesfromthecapital，tothenorthwardofCapeFrio。Igladlyacceptedhiskindofferofallowingmetoaccompanyhim。
　　April8th——Ourpartyamountedtoseven。Thefirststagewasveryinteresting。Thedaywaspowerfullyhot，andaswepassedthroughthewoods，everythingwasmotionless，exceptingthelargeandbrilliantbutterflies，whichlazilyflutteredabout。TheviewseenwhencrossingthehillsbehindPraiaGrandewasmostbeautiful；thecolourswereintense，andtheprevailingtintadarkblue；theskyandthecalmwatersofthebayviedwitheachotherinsplendour。Afterpassingthroughsomecultivatedcountry，weenteredaforest，whichinthegrandeurofallitspartscouldnotbeexceeded。
　　WearrivedbymiddayatIthacaia；thissmallvillageissituatedonaplain，androundthecentralhousearethehutsofthenegroes。These，fromtheirregularformandposition，remindedmeofthedrawingsoftheHottentothabitationsinSouthernAfrica。Asthemoonroseearly，wedeterminedtostartthesameeveningforoursleeping-placeattheLagoaMarica。Asitwasgrowingdarkwepassedunderoneofthemassive，bare，andsteephillsofgranitewhicharesocommoninthiscountry。Thisspotisnotoriousfromhavingbeen，foralongtime，theresidenceofsomerunawayslaves，who，bycultivatingalittlegroundnearthetop，contrivedtoekeoutasubsistence。Atlengththeywerediscovered，andapartyofsoldiersbeingsent，thewholewereseizedwiththeexceptionofoneoldwoman，who，soonerthanagainbeledintoslavery，dashedherselftopiecesfromthesummitofthemountain。InaRomanmatronthiswouldhavebeencalledthenobleloveoffreedom：inapoornegressitismerebrutalobstinacy。
　　Wecontinuedridingforsomehours。Forthefewlastmilestheroadwasintricate，anditpassedthroughadesertwasteofmarshesandlagoons。
　　Thescenebythedimmedlightofthemoonwasmostdesolate。Afewfirefliesflittedbyus；andthesolitarysnipe，asitrose，uttereditsplaintivecry。Thedistantandsullenroaroftheseascarcelybrokethestillnessofthenight。