NeartheGuardiawefindthesouthernlimitoftwoEuropeanplants，nowbecomeextraordinarilycommon。Thefennelingreatprofusioncoverstheditch-banksintheneighbourhoodofBuenosAyres，MonteVideo，andothertowns。ButthecardoonCynaracardunculushasafarwiderrange：[9]itoccursintheselatitudesonbothsidesofthe，Cordillera，acrossthecontinent。IsawitinunfrequentedspotsinChile，EntreRios，andBandaOriental。Inthelattercountryalone，verymanyprobablyseveralhundredsquaremilesarecoveredbyonemassofthesepricklyplants，andareimpenetrablebymanorbeast。Overtheundulatingplains，wherethesegreatbedsoccur，nothingelsecannowlive。Beforetheirintroduction，however，thesurfacemusthavesupported，asinotherparts，arankherbage。Idoubtwhetheranycaseisonrecordofaninvasiononsograndascaleofoneplantovertheaborigines。AsIhavealreadysaid，InowheresawthecardoonsouthoftheSalado；butitisprobablethatinproportionasthatcountrybecomesinhabited，thecardoonwillextenditslimits。ThecaseisdifferentwiththegiantthistlewithvariegatedleavesofthePampas，forImetwithitinthevalleyoftheSauce。AccordingtotheprinciplessowelllaiddownbyMr。Lyell，fewcountrieshaveundergonemoreremarkablechanges，sincetheyear1535，whenthefirstcolonistofLaPlatalandedwithseventy-twohorses。Thecountlessherdsofhorses，cattle，andsheep，notonlyhavealteredthewholeaspectofthevegetation，buttheyhavealmostbanishedtheguanaco，deerandostrich。Numberlessotherchangesmustlikewisehavetakenplace；thewildpiginsomepartsprobablyreplacesthepeccari；packsofwilddogsmaybeheardhowlingonthewoodedbanksoftheless-frequentedstreams；andthecommoncat，alteredintoalargeandfierceanimal，inhabitsrockyhills。AsM。d’Orbignyhasremarked，theincreaseinnumbersofthecarrion-vulture，sincetheintroductionofthedomesticanimals，musthavebeeninfinitelygreat；
andwehavegivenreasonsforbelievingthattheyhaveextendedtheirsouthernrange。Nodoubtmanyplants，besidesthecardoonandfennel，arenaturalized；
thustheislandsnearthemouthoftheParana，arethicklyclothedwithpeachandorangetrees，springingfromseedscarriedtherebythewatersoftheriver。
WhilechanginghorsesattheGuardiaseveralpeoplequestionedusmuchaboutthearmy，——IneversawanythingliketheenthusiasmforRosas，andforthesuccessofthe“mostjustofallwars，becauseagainstbarbarians。”
Thisexpression，itmustbeconfessed，isverynatural，fortilllately，neitherman，womannorhorse，wassafefromtheattacksoftheIndians。