第10章

4degs。S。tolat。32degs。S。，maybedescribedasadesert；onthiswesterncoast，northwardoflat。4degs。S。，wherethetrade-windlosesitsregularity，andheavytorrentsofrainfallperiodically，theshoresofthePacific，soutterlydesertinPeru，assumenearCapeBlancothecharacterofluxuriancesocelebratedatGuyaquilandPanama。Henceinthesouthernandnorthernpartsofthecontinent，theforestanddesertlandsoccupyreversedpositionswithrespecttotheCordillera，andthesepositionsareapparentlydeterminedbythedirectionoftheprevalentwinds。Inthemiddleofthecontinentthereisabroadintermediateband，includingcentralChileandtheprovincesofLaPlata，wheretherain-bringingwindshavenottopassoverloftymountains，andwherethelandisneitheradesertnorcoveredbyforests。

Buteventherule，ifconfinedtoSouthAmerica，oftreesflourishingonlyinaclimaterenderedhumidbyrain-bearingwinds，hasastronglymarkedexceptioninthecaseoftheFalklandIslands。Theseislands，situatedinthesamelatitudewithTierradelFuegoandonlybetweentwoandthreehundredmilesdistantfromit，havinganearlysimilarclimate，withageologicalformationalmostidentical，withfavourablesituationsandthesamekindofpeatysoil，yetcanboastoffewplantsdeservingeventhetitleofbushes；whilstinTierradelFuegoitisimpossibletofindanacreoflandnotcoveredbythedensestforest。Inthiscase，boththedirectionoftheheavygalesofwindandofthecurrentsoftheseaarefavourabletothetransportofseedsfromTierradelFuego，asisshownbythecanoesandtrunksoftreesdriftedfromthatcountry，andfrequentlythrownontheshoresoftheWesternFalkland。Henceperhapsitis，thattherearemanyplantsincommontothetwocountriesbutwithrespecttothetreesofTierradelFuego，evenattemptsmadetotransplantthemhavefailed。

DuringourstayatMaldonadoIcollectedseveralquadrupeds，eightykindsofbirds，andmanyreptiles，includingninespeciesofsnakes。Oftheindigenousmammalia，theonlyonenowleftofanysize，whichiscommon，istheCervuscampestris。Thisdeerisexceedinglyabundant，ofteninsmallherds，throughoutthecountriesborderingthePlataandinNorthernPatagonia。

Ifapersoncrawlingclosealongtheground，slowlyadvancestowardsaherd，thedeerfrequently，outofcuriosity，approachtoreconnoitrehim。

Ihavebythismeans，killedfromonespot，threeoutofthesameherd。

Althoughsotameandinquisitive，yetwhenapproachedonhorseback，theyareexceedinglywary。Inthiscountrynobodygoesonfoot，andthedeerknowsmanasitsenemyonlywhenheismountedandarmedwiththebolas。

AtBahiaBlanca，arecentestablishmentinNorthernPatagonia，Iwassurprisedtofindhowlittlethedeercaredforthenoiseofagun：onedayIfiredtentimesfromwithineightyyardsatoneanimal；anditwasmuchmorestartledattheballcuttingupthegroundthanatthereportoftherifle。

Mypowderbeingexhausted，Iwasobligedtogetup(tomyshameasasportsmanbeitspoken，thoughwellabletokillbirdsonthewing)andhallootillthedeerranaway。

Themostcuriousfactwithrespecttothisanimal，istheoverpoweringlystrongandoffensiveodourwhichproceedsfromthebuck。Itisquiteindescribable：

severaltimeswhilstskinningthespecimenwhichisnowmountedattheZoologicalMuseum，Iwasalmostovercomebynausea。Itieduptheskininasilkpocket-handkerchief，andsocarriedithome：thishandkerchief，afterbeingwellwashed，Icontinuallyused，anditwasofcourseasrepeatedlywashed；yeteverytime，foraspaceofoneyearandsevenmonths，whenfirstunfolded，Idistinctlyperceivedtheodour。Thisappearsanastonishinginstanceofthepermanenceofsomematter，whichneverthelessinitsnaturemustbemostsubtileandvolatile。Frequently，whenpassingatthedistanceofhalfamiletoleewardofaherd，Ihaveperceivedthewholeairtaintedwiththeeffluvium。Ibelievethesmellfromthebuckismostpowerfulattheperiodwhenitshornsareperfect，orfreefromthehairyskin。

Wheninthisstatethemeatis，ofcourse，quiteuneatable；buttheGauchosassert，thatifburiedforsometimeinfreshearth，thetaintisremoved。

IhavesomewherereadthattheislandersinthenorthofScotlandtreattherankcarcassesofthefish-eatingbirdsinthesamemanner。

TheorderRodentiaishereverynumerousinspecies：ofmicealoneI

obtainednolessthaneightkinds。[4]Thelargestgnawinganimalintheworld，theHydrochaeruscapybara(thewater-hog)，isherealsocommon。OnewhichIshotatMonteVideoweighedninety-eightpounds：itslengthfromtheendofthesnouttothestump-liketail，wasthreefeettwoinches；anditsgirththreefeeteight。ThesegreatRodentsoccasionallyfrequenttheislandsinthemouthofthePlata，wherethewaterisquitesalt，butarefarmoreabundantonthebordersoffresh-waterlakesandrivers。NearMaldonadothreeorfourgenerallylivetogether。

Inthedaytimetheyeitherlieamongtheaquaticplants，oropenlyfeedontheturfplain。[5]Whenviewedatadistance，fromtheirmannerofwalkingandcolourtheyresemblepigs：butwhenseatedontheirhaunches，andattentivelywatchinganyobjectwithoneeye，theyreassumetheappearanceoftheircongeners，caviesandrabbits。Boththefrontandsideviewoftheirheadhasquitealudicrousaspect，fromthegreatdepthoftheirjaw。Theseanimals，atMaldonado，wereverytame；

bycautiouslywalking，Iapproachedwithinthreeyardsoffouroldones。

Thistamenessmayprobablybeaccountedfor，bytheJaguarhavingbeenbanishedforsomeyears，andbytheGauchonotthinkingitworthhiswhiletohuntthem。AsIapproachednearerandnearertheyfrequentlymadetheirpeculiarnoise，whichisalowabruptgrunt，nothavingmuchactualsound，butratherarisingfromthesuddenexpulsionofair：theonlynoiseIknowatalllikeit，isthefirsthoarsebarkofalargedog。Havingwatchedthefourfromalmostwithinarm’slength(andtheyme)forseveralminutes，theyrushedintothewateratfullgallopwiththegreatestimpetuosity，andemittedatthesametimetheirbark。Afterdivingashortdistancetheycameagaintothesurface，butonlyjustshowedtheupperpartoftheirheads。Whenthefemaleisswimminginthewater，andhasyoungones，theyaresaidtositonherback。Theseanimalsareeasilykilledinnumbers；

buttheirskinsareoftriflingvalue，andthemeatisveryindifferent。

OntheislandsintheRioParanatheyareexceedinglyabundant，andaffordtheordinarypreytotheJaguar。

TheTucutuco(CtenomysBrasiliensis)isacurioussmallanimal，whichmaybebrieflydescribedasaGnawer，withthehabitsofamole。Itisextremelynumerousinsomepartsofthecountry，butitisdifficulttobeprocured，andnever，Ibelieve，comesoutoftheground。Itthrowsupatthemouthofitsburrowshillocksofearthlikethoseofthemole，butsmaller。Considerabletractsofcountryaresocompletelyunderminedbytheseanimals，thathorsesinpassingover，sinkabovetheirfetlocks。

Thetucutucosappear，toacertaindegree，tobegregarious：themanwhoprocuredthespecimensformehadcaughtsixtogether，andhesaidthiswasacommonoccurrence。Theyarenocturnalintheirhabits；andtheirprincipalfoodistherootsofplants，whicharetheobjectoftheirextensiveandsuperficialburrows。Thisanimalisuniversallyknownbyaverypeculiarnoisewhichitmakeswhenbeneaththeground。Aperson，thefirsttimehehearsit，ismuchsurprised；foritisnoteasytotellwhenceitcomes，norisitpossibletoguesswhatkindofcreatureuttersit。Thenoiseconsistsinashort，butnotrough，nasalgrunt，whichismonotonouslyrepeatedaboutfourtimesinquicksuccession：[6]thenameTucutucoisgiveninimitationofthesound。Wherethisanimalisabundant，itmaybeheardatalltimesoftheday，andsometimesdirectlybeneathone’sfeet。Whenkeptinaroom，thetucutucosmovebothslowlyandclumsily，whichappearsowingtotheoutwardactionoftheirhindlegs；

andtheyarequiteincapable，fromthesocketofthethigh-bonenothavingacertainligament，ofjumpingeventhesmallestverticalheight。Theyareverystupidinmakinganyattempttoescape；whenangryorfrightenedtheyutterthetucutuco。OfthoseIkeptaliveseveral，eventhefirstday，becamequitetame，notattemptingtobiteortorunaway；otherswerealittlewilder。

Themanwhocaughtthemassertedthatverymanyareinvariablyfoundblind。AspecimenwhichIpreservedinspiritswasinthisstate；Mr。Reidconsidersittobetheeffectofinflammationinthenictitatingmembrane。

WhentheanimalwasaliveIplacedmyfingerwithinhalfaninchofitshead，andnottheslightestnoticewastaken：itmadeitsway，however，abouttheroomnearlyaswellastheothers。Consideringthestrictlysubterraneanhabitsofthetucutuco，theblindness，thoughsocommon，cannotbeaveryseriousevil；yetitappearsstrangethatanyanimalshouldpossessanorganfrequentlysubjecttobeinjured。Lamarckwouldhavebeendelightedwiththisfact，hadheknownit，whenspeculating[7](probablywithmoretruththanusualwithhim)onthegradually_acquired_

blindnessoftheAsphalax，aGnawerlivingunderground，andoftheProteus，areptilelivingindarkcavernsfilledwithwater；inbothofwhichanimalstheeyeisinanalmostrudimentarystate，andiscoveredbyatendinousmembraneandskin。Inthecommonmoletheeyeisextraordinarilysmallbutperfect，thoughmanyanatomistsdoubtwhetheritisconnectedwiththetrueopticnerve；itsvisionmustcertainlybeimperfect，thoughprobablyusefultotheanimalwhenitleavesitsburrow。Inthetucutuco，whichIbelievenevercomestothesurfaceoftheground，theeyeisratherlarger，butoftenrenderedblindanduseless，thoughwithoutapparentlycausinganyinconveniencetotheanimal；nodoubtLamarckwouldhavesaidthatthetucutucoisnowpassingintothestateoftheAsphalaxandProteus。

Birdsofmanykindsareextremelyabundantontheundulating，grassyplainsaroundMaldonado。ThereareseveralspeciesofafamilyalliedinstructureandmannerstoourStarling：oneofthese(Molothrusniger)isremarkablefromitshabits。Severalmayoftenbeseenstandingtogetherontbebackofacoworhorse；andwhileperchedonahedge，plumingthemselvesinthesun，theysometimesattempttosing，orrathertohiss；thenoisebeingverypeculiar，resemblingthatofbubblesofairpassingrapidlyfromasmallorificeunderwater，soastoproduceanacutesound。AccordingtoAzara，thisbird，likethecuckoo，depositsitseggsinotherbirds’

nests。Iwasseveraltimestoldbythecountrypeoplethattherecertainlyissomebirdhavingthishabit；andmyassistantincollecting，whoisaveryaccurateperson，foundanestofthesparrowofthiscountry(Zonotrichiamatutina)，withoneegginitlargerthantheothers，andofadifferentcolourandshape。InNorthAmericathereisanotherspeciesofMolothrus(M。pecoris)，whichhasasimilarcuckoo-likehabit，andwhichismostcloselyalliedineveryrespecttothespeciesfromthePlata，eveninsuchtriflingpeculiaritiesasstandingonthebacksofcattle；itdiffersonlyinbeingalittlesmaller，andinitsplumageandeggsbeingofaslightlydifferentshadeofcolour。Thiscloseagreementinstructureandhabits，inrepresentativespeciescomingfromoppositequartersofagreatcontinent，alwaysstrikesoneasinteresting，thoughofcommonoccurrence。

Mr。Swainsonhaswellremarked，[8]thatwiththeexceptionoftheMolothruspecoris，towhichmustbeaddedtheM。niger，thecuckoosaretheonlybirdswhichcanbecalledtrulyparasitical；namely，suchas“fastenthemselves，asitwere，onanotherlivinganimal，whoseanimalheatbringstheiryoungintolife，whosefoodtheyliveupon，andwhosedeathwouldcausetheirsduringtheperiodofinfancy。”Itisremarkablethatsomeofthespecies，butnotall，bothoftheCuckooandMolothrus，shouldagreeinthisonestrangehabitoftheirparasiticalpropagation，whilstopposedtoeachotherinalmosteveryotherhabit：themolothrus，likeourstarling，iseminentlysociable，andlivesontheopenplainswithoutartordisguise：thecuckoo，aseveryoneknows，isasingularlyshybird；itfrequentsthemostretiredthickets，andfeedsonfruitandcaterpillars。Instructurealsothesetwogeneraarewidelyremovedfromeachother。Manytheories，evenphrenologicaltheories，havebeenadvancedtoexplaintheoriginofthecuckoolayingitseggsinotherbirds’nests。