the malay archipelago-1-第5节

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he　Archipelago。

The　great　contrast　between　the　two　divisions　of　the　Archipelago　is　nowhere　so　abruptly　exhibited　as　on　passing　from　the　island　of　Bali　to　that　of　Lombock；　where　the　two　regions　are　in　closest　proximity。　In　Bali　we　have　barbets；　fruit…thrushes；　and　woodpeckers；　on　passing　over　to　Lombock　these　are　seen　no　more；　but　we　have　abundance　of　cockatoos；　honeysuckers；　and　brush…　turkeys；　which　are　equally　unknown　in　Bali；　or　any　island　further　west。　＇I　was　informed；　however；　that　there　were　a　few　cockatoos　at　one　spot　on　the　west　of　Bali；　showing　that　the　intermingling　of　the　productions　of　these　islands　is　now　going　on。＇　The　strait　is　here　fifteen　miles　wide；　so　that　we　may　pass　in　two　hours　from　one　great　division　of　the　earth　to　another；　differing　as　essentially　in　their　animal　life　as　Europe　does　from　America。　If　we　travel　from　Java　or　Borneo　to　Celebes　or　the　Moluccas；　the　difference　is　still　more　striking。　In　the　first；　the　forests　abound　in　monkeys　of　many　kinds；　wild　cats；　deer；　civets；　and　otters；　and　numerous　varieties　of　squirrels　are　constantly　met　with。　In　the　latter　none　of　these　occur；　but　the　prehensile…　tailed　Cuscus　is　almost　the　only　terrestrial　mammal　seen；　except　wild　pigs；　which　are　found　in　all　the　islands；　and　deer　（which　have　probably　been　recently　introduced）　in　Celebes　and　the　Moluccas。　The　birds　which　are　most　abundant　in　the　Western　Islands　are　woodpeckers；　barbets；　trogons；　fruit…thrushes；　and　leaf…thrushes；　they　are　seen　daily；　and　form　the　great　ornithological　features　of　the　country。　In　the　Eastern　Islands　these　are　absolutely　unknown；　honeysuckers　and　small　lories　being　the　most　common　birds；　so　that　the　naturalist　feels　himself　in　a　new　world；　and　can　hardly　realize　that　he　has　passed　from　the　one　region　to　the　other　in　a　few　days；　without　ever　being　out　of　sight　of　land。

The　inference　that　we　must　draw　from　these　facts　is；　undoubtedly；　that　the　whole　of　the　islands　eastwards　beyond　Java　and　Borneo　do　essentially　form　a　part　of　a　former　Australian　or　Pacific　continent；　although　some　of　them　may　never　have　been　actually　joined　to　it。　This　continent　must　have　been　broken　up　not　only　before　the　Western　Islands　were　separated　from　Asia；　but　probably　before　the　extreme　southeastern　portion　of　Asia　was　raised　above　the　waters　of　the　ocean；　for　a　great　part　of　the　land　of　Borneo　and　Java　is　known　to　be　geologically　of　quite　recent　formation；　while　the　very　great　difference　of　species；　and　in　many　cases　of　genera　also；　between　the　productions　of　the　Eastern　Malay　Islands　and　Australia；　as　well　as　the　great　depth　of　the　sea　now　separating　them；　all　point　to　a　comparatively　long　period　of　isolation。

It　is　interesting　to　observe　among　the　islands　themselves　how　a　shallow　sea　always　intimates　a　recent　land　connexion。　The　Aru　Islands；　Mysol；　and　Waigiou；　as　well　as　Jobie；　agree　with　New　Guinea　in　their　species　of　mammalia　and　birds　much　more　closely　than　they　do　with　the　Moluccas；　and　we　find　that　they　are　all　united　to　New　Guinea　by　a　shallow　sea。　In　fact；　the　100…fathom　line　round　New　Guinea　marks　out　accurately　the　range　of　the　true　Paradise　birds。

It　is　further　to　be　notedand　this　is　a　very　interesting　point　in　connection　with　theories　of　the　dependence　of　special　forms　of　life　on　external　conditionsthat　this　division　of　the　Archipelago　into　two　regions　characterised　by　a　striking　diversity　in　their　natural　productions　does　not　in　any　way　correspond　to　the　main　physical　or　climatal　divisions　of　the　surface。　The　great　volcanic　chain　runs　through　both　parts；　and　appears　to　produce　no　effect　in　assimilating　their　productions。　Borneo　closely　resembles　New　Guinea　not　only　in　its　vast　size　and　its　freedom　from　volcanoes；　but　in　its　variety　of　geological　structure；　its　uniformity　of　climate；　and　the　general　aspect　of　the　forest　vegetation　that　clothes　its　surface。　The　Moluccas　are　the　counterpart　of　the　Philippines　in　their　volcanic　structure；　their　extreme　fertility；　their　luxuriant　forests；　and　their　frequent　earthquakes；　and　Bali　with　the　east　end　of　Java　has　a　climate　almost　as　dry　and　a　soil　almost　as　arid　as　that　of　Timor。　Yet　between　these　corresponding　groups　of　islands；　constructed　as　it　were　after　the　same　pattern；　subjected　to　the　same　climate；　and　bathed　by　the　same　oceans；　there　exists　the　greatest　possible　contrast　when　we　compare　their　animal　productions。　Nowhere　does　the　ancient　doctrinethat　differences　or　similarities　in　the　various　forms　of　life　that　inhabit　different　countries　are　due　to　corresponding　physical　differences　or　similarities　in　the　countries　themselvesmeet　with　so　direct　and　palpable　a　contradiction。　Borneo　and　New　Guinea；　as　alike　physically　as　two　distinct　countries　can　be；　are　zoologically　wide　as　the　poles　asunder；　while　Australia；　with　its　dry　winds；　its　open　plains；　its　stony　deserts；　and　its　temperate　climate；　yet　produces　birds　and　quadrupeds　which　are　closely　related　to　those　inhabiting　the　hot　damp　luxuriant　forests；　which　everywhere　clothe　the　plains　and　mountains　of　New　Guinea。

In　order　to　illustrate　more　clearly　the　means　by　which　I　suppose　this　great　contrast　has　been　brought　about；　let　us　consider　what　would　occur　if　two　strongly　contrasted　divisions　of　the　earth　were；　by　natural　means；　brought　into　proximity。　No　two　parts　of　the　world　differ　so　radically　in　their　productions　as　Asia　and　Australia；　but　the　difference　between　Africa　and　South　America　is　also　very　great；　and　these　two　regions　will　well　serve　to　illustrate　the　question　we　are　considering。　On　the　one　side　we　have　baboons；　lions；　elephants；　buffaloes；　and　giraffes；　on　the　other　spider…monkeys；　pumas；　tapirs；　anteaters；　and　sloths；　while　among　birds；　the　hornbills；　turacos；　orioles；　and　honeysuckers　of　Africa　contrast　strongly　with　the　toucans；　macaws；　chatterers；　and　hummingbirds　of　America。

Now　let　us　endeavour　to　imagine　（what　it　is　very　probable　may　occur　in　future　ages）　that　a　slow　upheaval　of　the　bed　of　the　Atlantic　should　take　place；　while　at　the　same　time　earthquake…　shocks　and　volcanic　action　on　the　land　should　cause　increased　volumes　of　sediment　to　be　poured　down　by　the　rivers；　so　that　the　two　continents　should　gradually　spread　out　by　the　addition　of　newly…formed　lands；　and　thus　reduce　the　Atlantic　which　now　separates　them；　to　an　arm　of　the　sea　a　few　hundred　miles　wide。　At　the　same　time　we　may　suppose　islands　to　be　upheaved　in　mid…　channel；　and；　as　the　subterranean　forces　varied　in　intensity；　and　shifted　their　points　of　greatest　action；　these　islands　would　sometimes　become　connected　with　the　land　on　one　side　or　other　of　the　strait；　and　at　other　times　again　be　separated　from　it。　Several　islands　would　at　one　time　be　joined　together；　at　another　would　be　broken　up　again；　until　at　last；　after　many　long　ages　of　such　intermittent　action；　we　might　have　an　irregular　archipelago　of　islands　filling　up　the　ocean　channel　of　the　Atlantic；　in　whose　appearance　and　arrangement　we　could　discover　nothing　to　tell　us　which　had　been　connected　with　Africa　and　which　with　America。　The　animals　and　plants　inhabiting　these　islands　would；　however；　certainly　reveal　this　portion　of　their　former　history。　On　those　islands　which　had　ever　formed　a　part　of　the　South　American　continent；　we　should　be　sure　to　find　such　common　birds　as　chatterers　and　toucans　and　hummingbirds；　and　some　of　the　peculiar　American　quadrupeds；　while　on　those　which　had　been　separated　from　Africa；　hornbills；　orioles；　and　honeysuckers　would　as　certainly　be　found。　Some　portion　of　the　upraised　land　might　at　different　times　have　had　a　temporary　connection　with　both　continents；　and　would　then　contain　a　certain　amount　of　mixture　in　its　living　inhabitants。　Such　seems　to　have　been　the　case　with　the　islands　of　Celebes　and　the　Philippines。　Other　islands；　again；　though　in　such　close　proximity　as　Bali　and　Lombock；　might　each　exhibit　an　almost　unmixed　sample　of　the　productions　of　the　continents　of　which　they　had　directly　or　indirectly　once　formed　a　part。

In　the　Malay　Archipelago　we　have；　I　believe；　a　case　exactly　parallel　to　that　which　I　have　here　supposed。　We　have　indications　of　a　vast　continent；　with　a　peculiar　fauna　and　flora　having　been　gradually　and　irregularly　broken　up；　the　island　of　Celebes　probably　marking　its　furthest　westward　extension；　beyond　which　was　a　wide　ocean。　At　the　same　time　Asia　appears　to　have　been　extending　its　limits　in　a　southeast　direction；　first　in　an　unbroken　mass；　then　separated　into　islands　as　we　now　see　it；　and　almost　coming　into　actual　contact　with　the　scattered　fragments　of　the　great　southern　land。

From　this　outline　of　the　subject；　it　will　be　evident　how　important　an　adjunct　Natural　History　is　to　Geology；　not　only　in　interpreting　the　fragments　of　extinct　animals　found　in　the　earth's　crust；　but　in　determining　past　changes　in　the　surface　which　have　left　no　geological　record。　It　is　certainly　a　wonderful　and　unexpected　fact　that　an　accurate　knowledge　of　the　distribution　of　birds　and　insects　should　enable　us　to　map　out　lands　and　continents　which　disappeared　beneath　the　ocean　long　before　the　earliest　traditions　of　the　human　race。　Wherever　the　geologist　can　explore　the　earth's　surface；　he　can　read　much　of　its　past　history；　and　can　determine　approximately　its　latest　movements　above　and　below　the　sea…level；　but　wherever　ocean