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rms¡¡which¡¡in¡¡the¡¡opinion¡¡of¡¡some¡¡naturalists¡¡come¡¡very¡¡near¡¡to£»¡¡but¡¡do¡¡not¡¡quite¡¡arrive¡¡at¡¡the¡¡rank¡¡of¡¡species£»¡¡or£»¡¡again£»¡¡between¡¡sub¡­species¡¡and¡¡well¡­marked¡¡varieties£»¡¡or¡¡between¡¡lesser¡¡varieties¡¡and¡¡individual¡¡differences¡£¡¡These¡¡differences¡¡blend¡¡into¡¡each¡¡other¡¡in¡¡an¡¡insensible¡¡series£»¡¡and¡¡a¡¡series¡¡impresses¡¡the¡¡mind¡¡with¡¡the¡¡idea¡¡of¡¡an¡¡actual¡¡passage¡£¡¡
Hence¡¡I¡¡look¡¡at¡¡individual¡¡differences£»¡¡though¡¡of¡¡small¡¡interest¡¡to¡¡the¡¡systematist£»¡¡as¡¡of¡¡high¡¡importance¡¡for¡¡us£»¡¡as¡¡being¡¡the¡¡first¡¡step¡¡towards¡¡such¡¡slight¡¡varieties¡¡as¡¡are¡¡barely¡¡thought¡¡worth¡¡recording¡¡in¡¡works¡¡on¡¡natural¡¡history¡£¡¡And¡¡I¡¡look¡¡at¡¡varieties¡¡which¡¡are¡¡in¡¡any¡¡degree¡¡more¡¡distinct¡¡and¡¡permanent£»¡¡as¡¡steps¡¡leading¡¡to¡¡more¡¡strongly¡¡marked¡¡and¡¡more¡¡permanent¡¡varieties£»¡¡and¡¡at¡¡these¡¡latter£»¡¡as¡¡leading¡¡to¡¡sub¡­species£»¡¡and¡¡to¡¡species¡£¡¡The¡¡passage¡¡from¡¡one¡¡stage¡¡of¡¡difference¡¡to¡¡another¡¡and¡¡higher¡¡stage¡¡may¡¡be£»¡¡in¡¡some¡¡cases£»¡¡due¡¡merely¡¡to¡¡the¡¡long¡­continued¡¡action¡¡of¡¡different¡¡physical¡¡conditions¡¡in¡¡two¡¡different¡¡regions£»¡¡but¡¡I¡¡have¡¡not¡¡much¡¡faith¡¡in¡¡this¡¡view£»¡¡and¡¡I¡¡attribute¡¡the¡¡passage¡¡of¡¡a¡¡variety£»¡¡from¡¡a¡¡state¡¡in¡¡which¡¡it¡¡differs¡¡very¡¡slightly¡¡from¡¡its¡¡parent¡¡to¡¡one¡¡in¡¡which¡¡it¡¡differs¡¡more£»¡¡to¡¡the¡¡action¡¡of¡¡natural¡¡selection¡¡in¡¡accumulating¡¡£¨as¡¡will¡¡hereafter¡¡be¡¡more¡¡fully¡¡explained£©¡¡differences¡¡of¡¡structure¡¡in¡¡certain¡¡definite¡¡directions¡£¡¡Hence¡¡I¡¡believe¡¡a¡¡well¡­marked¡¡variety¡¡may¡¡be¡¡justly¡¡called¡¡an¡¡incipient¡¡species£»¡¡but¡¡whether¡¡this¡¡belief¡¡be¡¡justifiable¡¡must¡¡be¡¡judged¡¡of¡¡by¡¡the¡¡general¡¡weight¡¡of¡¡the¡¡several¡¡facts¡¡and¡¡views¡¡given¡¡throughout¡¡this¡¡work¡£¡¡
It¡¡need¡¡not¡¡be¡¡supposed¡¡that¡¡all¡¡varieties¡¡or¡¡incipient¡¡species¡¡necessarily¡¡attain¡¡the¡¡rank¡¡of¡¡species¡£¡¡They¡¡may¡¡whilst¡¡in¡¡this¡¡incipient¡¡state¡¡become¡¡extinct£»¡¡or¡¡they¡¡may¡¡endure¡¡as¡¡varieties¡¡for¡¡very¡¡long¡¡periods£»¡¡as¡¡has¡¡been¡¡shown¡¡to¡¡be¡¡the¡¡case¡¡by¡¡Mr¡¡Wollaston¡¡with¡¡the¡¡varieties¡¡of¡¡certain¡¡fossil¡¡land¡­shells¡¡in¡¡Madeira¡£¡¡If¡¡a¡¡variety¡¡were¡¡to¡¡flourish¡¡so¡¡as¡¡to¡¡exceed¡¡in¡¡numbers¡¡the¡¡parent¡¡species£»¡¡it¡¡would¡¡then¡¡rank¡¡as¡¡the¡¡species£»¡¡and¡¡the¡¡species¡¡as¡¡the¡¡variety£»¡¡or¡¡it¡¡might¡¡come¡¡to¡¡supplant¡¡and¡¡exterminate¡¡the¡¡parent¡¡species£»¡¡or¡¡both¡¡might¡¡co¡­exist£»¡¡and¡¡both¡¡rank¡¡as¡¡independent¡¡species¡£¡¡But¡¡we¡¡shall¡¡hereafter¡¡have¡¡to¡¡return¡¡to¡¡this¡¡subject¡£¡¡
From¡¡these¡¡remarks¡¡it¡¡will¡¡be¡¡seen¡¡that¡¡I¡¡look¡¡at¡¡the¡¡term¡¡species£»¡¡as¡¡one¡¡arbitrarily¡¡given¡¡for¡¡the¡¡sake¡¡of¡¡convenience¡¡to¡¡a¡¡set¡¡of¡¡individuals¡¡closely¡¡resembling¡¡each¡¡other£»¡¡and¡¡that¡¡it¡¡does¡¡not¡¡essentially¡¡differ¡¡from¡¡the¡¡term¡¡variety£»¡¡which¡¡is¡¡given¡¡to¡¡less¡¡distinct¡¡and¡¡more¡¡fluctuating¡¡forms¡£¡¡The¡¡term¡¡variety£»¡¡again£»¡¡in¡¡comparison¡¡with¡¡mere¡¡individual¡¡differences£»¡¡is¡¡also¡¡applied¡¡arbitrarily£»¡¡and¡¡for¡¡mere¡¡convenience¡¡sake¡£¡¡
Guided¡¡by¡¡theoretical¡¡considerations£»¡¡I¡¡thought¡¡that¡¡some¡¡interesting¡¡results¡¡might¡¡be¡¡obtained¡¡in¡¡regard¡¡to¡¡the¡¡nature¡¡and¡¡relations¡¡of¡¡the¡¡species¡¡which¡¡vary¡¡most£»¡¡by¡¡tabulating¡¡all¡¡the¡¡varieties¡¡in¡¡several¡¡well¡­worked¡¡floras¡£¡¡At¡¡first¡¡this¡¡seemed¡¡a¡¡simple¡¡task£»¡¡but¡¡Mr¡¡H¡£¡¡C¡£¡¡Watson£»¡¡to¡¡whom¡¡I¡¡am¡¡much¡¡indebted¡¡for¡¡valuable¡¡advice¡¡and¡¡assistance¡¡on¡¡this¡¡subject£»¡¡soon¡¡convinced¡¡me¡¡that¡¡there¡¡were¡¡many¡¡difficulties£»¡¡as¡¡did¡¡subsequently¡¡Dr¡¡Hooker£»¡¡even¡¡in¡¡stronger¡¡terms¡£¡¡I¡¡shall¡¡reserve¡¡for¡¡my¡¡future¡¡work¡¡the¡¡discussion¡¡of¡¡these¡¡difficulties£»¡¡and¡¡the¡¡tables¡¡themselves¡¡of¡¡the¡¡proportional¡¡numbers¡¡of¡¡the¡¡varying¡¡species¡£¡¡Dr¡¡Hooker¡¡permits¡¡me¡¡to¡¡add£»¡¡that¡¡after¡¡having¡¡carefully¡¡read¡¡my¡¡manuscript£»¡¡and¡¡examined¡¡the¡¡tables£»¡¡he¡¡thinks¡¡that¡¡the¡¡following¡¡statements¡¡are¡¡fairly¡¡well¡¡established¡£¡¡The¡¡whole¡¡subject£»¡¡however£»¡¡treated¡¡as¡¡it¡¡necessarily¡¡here¡¡is¡¡with¡¡much¡¡brevity£»¡¡is¡¡rather¡¡perplexing£»¡¡and¡¡allusions¡¡cannot¡¡be¡¡avoided¡¡to¡¡the¡¡'struggle¡¡for¡¡existence£»'¡¡'divergence¡¡of¡¡character£»'¡¡and¡¡other¡¡questions£»¡¡hereafter¡¡to¡¡be¡¡discussed¡£¡¡
Alph¡£¡¡De¡¡Candolle¡¡and¡¡others¡¡have¡¡shown¡¡that¡¡plants¡¡which¡¡have¡¡very¡¡wide¡¡ranges¡¡generally¡¡present¡¡varieties£»¡¡and¡¡this¡¡might¡¡have¡¡been¡¡expected£»¡¡as¡¡they¡¡become¡¡exposed¡¡to¡¡diverse¡¡physical¡¡conditions£»¡¡and¡¡as¡¡they¡¡come¡¡into¡¡competition¡¡£¨which£»¡¡as¡¡we¡¡shall¡¡hereafter¡¡see£»¡¡is¡¡a¡¡far¡¡more¡¡important¡¡circumstance£©¡¡with¡¡different¡¡sets¡¡of¡¡organic¡¡beings¡£¡¡But¡¡my¡¡tables¡¡further¡¡show¡¡that£»¡¡in¡¡any¡¡limited¡¡country£»¡¡the¡¡species¡¡which¡¡are¡¡most¡¡common£»¡¡that¡¡is¡¡abound¡¡most¡¡in¡¡individuals£»¡¡and¡¡the¡¡species¡¡which¡¡are¡¡most¡¡widely¡¡diffused¡¡within¡¡their¡¡own¡¡country¡¡£¨and¡¡this¡¡is¡¡a¡¡different¡¡consideration¡¡from¡¡wide¡¡range£»¡¡and¡¡to¡¡a¡¡certain¡¡extent¡¡from¡¡commonness£©£»¡¡often¡¡give¡¡rise¡¡to¡¡varieties¡¡sufficiently¡¡well¡­marked¡¡to¡¡have¡¡been¡¡recorded¡¡in¡¡botanical¡¡works¡£¡¡Hence¡¡it¡¡is¡¡the¡¡most¡¡flourishing£»¡¡or£»¡¡as¡¡they¡¡may¡¡be¡¡called£»¡¡the¡¡dominant¡¡species£»¡¡those¡¡which¡¡range¡¡widely¡¡over¡¡the¡¡world£»¡¡are¡¡the¡¡most¡¡diffused¡¡in¡¡their¡¡own¡¡country£»¡¡and¡¡are¡¡the¡¡most¡¡numerous¡¡in¡¡individuals£»¡¡which¡¡oftenest¡¡produce¡¡well¡­marked¡¡varieties£»¡¡or£»¡¡as¡¡I¡¡consider¡¡them£»¡¡incipient¡¡species¡£¡¡And¡¡this£»¡¡perhaps£»¡¡might¡¡have¡¡been¡¡anticipated£»¡¡for£»¡¡as¡¡varieties£»¡¡in¡¡order¡¡to¡¡become¡¡in¡¡any¡¡degree¡¡permanent£»¡¡necessarily¡¡have¡¡to¡¡struggle¡¡with¡¡the¡¡other¡¡inhabitants¡¡of¡¡the¡¡country£»¡¡the¡¡species¡¡which¡¡are¡¡already¡¡dominant¡¡will¡¡be¡¡the¡¡most¡¡likely¡¡to¡¡yield¡¡offspring¡¡which£»¡¡though¡¡in¡¡some¡¡slight¡¡degree¡¡modified£»¡¡will¡¡still¡¡inherit¡¡those¡¡advantages¡¡that¡¡enabled¡¡their¡¡parents¡¡to¡¡become¡¡dominant¡¡over¡¡their¡¡compatriots¡£¡¡
If¡¡the¡¡plants¡¡inhabiting¡¡a¡¡country¡¡and¡¡described¡¡in¡¡any¡¡Flora¡¡be¡¡divided¡¡into¡¡two¡¡equal¡¡masses£»¡¡all¡¡those¡¡in¡¡the¡¡larger¡¡genera¡¡being¡¡placed¡¡on¡¡one¡¡side£»¡¡and¡¡all¡¡those¡¡in¡¡the¡¡smaller¡¡genera¡¡on¡¡the¡¡other¡¡side£»¡¡a¡¡somewhat¡¡larger¡¡number¡¡of¡¡the¡¡very¡¡common¡¡and¡¡much¡¡diffused¡¡or¡¡dominant¡¡species¡¡will¡¡be¡¡found¡¡on¡¡the¡¡side¡¡of¡¡the¡¡larger¡¡genera¡£¡¡This£»¡¡again£»¡¡might¡¡have¡¡been¡¡anticipated£»¡¡for¡¡the¡¡mere¡¡fact¡¡of¡¡many¡¡species¡¡of¡¡the¡¡same¡¡genus¡¡inhabiting¡¡any¡¡country£»¡¡shows¡¡that¡¡there¡¡is¡¡something¡¡in¡¡the¡¡organic¡¡or¡¡inorganic¡¡conditions¡¡of¡¡that¡¡country¡¡favourable¡¡to¡¡the¡¡genus£»¡¡and£»¡¡consequently£»¡¡we¡¡might¡¡have¡¡expected¡¡to¡¡have¡¡found¡¡in¡¡the¡¡larger¡¡genera£»¡¡or¡¡those¡¡including¡¡many¡¡species£»¡¡a¡¡large¡¡proportional¡¡number¡¡of¡¡dominant¡¡species¡£¡¡But¡¡so¡¡many¡¡causes¡¡tend¡¡to¡¡obscure¡¡this¡¡result£»¡¡that¡¡I¡¡am¡¡surprised¡¡that¡¡my¡¡tables¡¡show¡¡even¡¡a¡¡small¡¡majority¡¡on¡¡the¡¡side¡¡of¡¡the¡¡larger¡¡genera¡£¡¡I¡¡will¡¡here¡¡allude¡¡to¡¡only¡¡two¡¡causes¡¡of¡¡obscurity¡£¡¡Fresh¡­water¡¡and¡¡salt¡­loving¡¡plants¡¡have¡¡generally¡¡very¡¡wide¡¡ranges¡¡and¡¡are¡¡much¡¡diffused£»¡¡but¡¡this¡¡seems¡¡to¡¡be¡¡connected¡¡with¡¡the¡¡nature¡¡of¡¡the¡¡stations¡¡inhabited¡¡by¡¡them£»¡¡and¡¡has¡¡little¡¡or¡¡no¡¡relation¡¡to¡¡the¡¡size¡¡of¡¡the¡¡genera¡¡to¡¡which¡¡the¡¡species¡¡belong¡£¡¡Again£»¡¡plants¡¡low¡¡in¡¡the¡¡scale¡¡of¡¡organisation¡¡are¡¡generally¡¡much¡¡more¡¡widely¡¡diffused¡¡than¡¡plants¡¡higher¡¡in¡¡the¡¡scale£»¡¡and¡¡here¡¡again¡¡there¡¡is¡¡no¡¡close¡¡relation¡¡to¡¡the¡¡size¡¡of¡¡the¡¡genera¡£¡¡The¡¡cause¡¡of¡¡lowly¡­organised¡¡plants¡¡ranging¡¡widely¡¡will¡¡be¡¡discussed¡¡in¡¡our¡¡chapter¡¡on¡¡geographical¡¡distribution¡£¡¡
From¡¡looking¡¡at¡¡species¡¡as¡¡only¡¡strongly¡­marked¡¡and¡¡well¡­defined¡¡varieties£»¡¡I¡¡was¡¡led¡¡to¡¡anticipate¡¡that¡¡the¡¡species¡¡of¡¡the¡¡larger¡¡genera¡¡in¡¡each¡¡country¡¡would¡¡oftener¡¡present¡¡varieties£»¡¡than¡¡the¡¡species¡¡of¡¡the¡¡smaller¡¡genera£»¡¡for¡¡wherever¡¡many¡¡closely¡¡related¡¡species¡¡£¨i¡£e¡£¡¡species¡¡of¡¡the¡¡same¡¡genus£©¡¡have¡¡been¡¡formed£»¡¡many¡¡varieties¡¡or¡¡incipient¡¡species¡¡ought£»¡¡as¡¡a¡¡general¡¡rule£»¡¡to¡¡be¡¡now¡¡forming¡£¡¡Where¡¡many¡¡large¡¡trees¡¡grow£»¡¡we¡¡expect¡¡to¡¡find¡¡saplings¡£¡¡Where¡¡many¡¡species¡¡of¡¡a¡¡genus¡¡have¡¡been¡¡formed¡¡through¡¡variation£»¡¡circumstances¡¡have¡¡been¡¡favourable¡¡for¡¡variation£»¡¡and¡¡hence¡¡we¡¡might¡¡expect¡¡that¡¡the¡¡circumstances¡¡would¡¡generally¡¡be¡¡still¡¡favourable¡¡to¡¡variation¡£¡¡On¡¡the¡¡other¡¡hand£»¡¡if¡¡we¡¡look¡¡at¡¡each¡¡species¡¡as¡¡a¡¡special¡¡act¡¡of¡¡creation£»¡¡there¡¡is¡¡no¡¡apparent¡¡reason¡¡why¡¡more¡¡varieties¡¡should¡¡occur¡¡in¡¡a¡¡group¡¡having¡¡many¡¡species£»¡¡than¡¡in¡¡one¡¡having¡¡few¡£¡¡
To¡¡test¡¡the¡¡truth¡¡of¡¡this¡¡anticipation¡¡I¡¡have¡¡arranged¡¡the¡¡plants¡¡of¡¡twelve¡¡countries£»¡¡and¡¡the¡¡coleopterous¡¡insects¡¡of¡¡two¡¡districts£»¡¡into¡¡two¡¡nearly¡¡equal¡¡masses£»¡¡the¡¡species¡¡of¡¡the¡¡larger¡¡genera¡¡on¡¡one¡¡side£»¡¡and¡¡those¡¡of¡¡the¡¡smaller¡¡genera¡¡on¡¡the¡¡other¡¡side£»¡¡and¡¡it¡¡has¡¡invariably¡¡proved¡¡to¡¡be¡¡the¡¡case¡¡that¡¡a¡¡larger¡¡proportion¡¡of¡¡the¡¡species¡¡on¡¡the¡¡side¡¡of¡¡the¡¡larger¡¡genera¡¡present¡¡varieties£»¡¡than¡¡on¡¡the¡¡side¡¡of¡¡the¡¡smaller¡¡genera¡£¡¡Moreover£»¡¡the¡¡species¡¡of¡¡the¡¡large¡¡genera¡¡which¡¡present¡¡any¡¡varieties£»¡¡invariably¡¡present¡¡a¡¡larger¡¡average¡¡number¡¡of¡¡varieties¡¡than¡¡do¡¡the¡¡species¡¡of¡¡the¡¡small¡¡genera¡£¡¡Both¡¡these¡¡results¡¡follow¡¡when¡¡another¡¡division¡¡is¡¡made£»¡¡and¡¡when¡¡all¡¡the¡¡smallest¡¡genera£»¡¡with¡¡from¡¡only¡¡one¡¡to¡¡four¡¡species£»¡¡are¡¡absolutely¡¡excluded¡¡from¡¡the¡¡tables¡£¡¡These¡¡facts¡¡are¡¡of¡¡plain¡¡signification¡¡on¡¡the¡¡view¡¡that¡¡species¡¡are¡¡only¡¡strongly¡¡marked¡¡and¡¡permanent¡¡varieties£»¡¡for¡¡whenever¡¡many¡¡species¡¡of¡¡the¡¡same¡¡genus¡¡have¡¡been¡¡formed£»¡¡or¡¡where£»¡¡if¡¡we¡¡may¡¡use¡¡the¡¡expression£»¡¡the¡¡manufactory¡¡of¡¡species¡¡has¡¡been¡¡active£»¡¡we¡¡ought¡¡generally¡¡to¡¡find¡¡the¡¡manufactory¡¡still¡¡in¡¡action£»¡¡more¡¡especially¡¡as¡¡we¡¡have¡¡every¡¡reason¡¡to¡¡believe¡¡the¡¡process¡¡of¡¡manufacturing¡¡new¡¡species¡¡to¡¡be¡¡a¡¡slow¡¡one¡£¡¡And¡¡this¡¡certainly¡¡is¡¡the¡¡case£»¡¡if¡¡varieties¡¡be¡¡looked¡¡at¡¡as¡¡incipient¡¡species£»¡¡for¡¡my¡¡tables¡¡clearly¡¡show¡¡as¡¡a¡¡general¡¡rule¡¡that£»¡¡wherever¡¡many¡¡species¡¡of¡¡a¡¡genus¡¡have¡¡been¡¡formed£»¡¡the¡¡species¡¡of¡¡that¡¡genus¡¡present¡¡a¡¡number¡¡of¡¡varieties£»¡¡that¡¡is¡¡of¡¡incipient¡¡species£»¡¡beyond¡¡the¡¡average¡£¡¡It¡¡is¡¡not¡¡that¡¡all¡¡large¡¡genera¡¡are¡¡now¡¡varying¡¡much£»¡¡and¡¡are¡¡thus¡¡increasing¡¡in¡¡the¡¡number¡¡of¡¡their¡¡species£»¡¡or¡¡that¡¡no¡¡small¡¡genera¡¡are¡¡now¡¡varying¡¡and¡¡increasing£»¡¡for¡¡if¡¡this¡¡had¡¡been¡¡so£»¡¡it¡¡would¡¡have¡¡been¡¡fatal¡¡to¡¡my¡¡theory£»¡¡inasmuch¡¡as¡¡geology¡¡plainly¡¡tells¡¡us¡¡that¡¡small¡¡genera¡¡have¡¡in¡¡the¡¡lapse¡¡of¡¡time¡¡often¡¡increased¡¡greatly¡¡in¡¡

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