the naturalist on the river amazons-第5部分

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tance　with　two　of　the　most　beautiful　productions　of　nature　in　this　department　namely；　the　Helicopis　Cupido　and　Endymion。　A　little　beyond　our　house；　one　of　the　narrow　green　lanes　which　I　have　already　mentioned　diverged　from　the　Monguba　avenue；　and　led；　between　enclosures　overrun　with　a　profusion　of　creeping　plants　and　glorious　flowers；　down　to　a　moist　hollow；　where　there　was　a　public　well　in　a　picturesque　nook；　buried　in　a　grove　of　Mucaja　palm　trees。　On　the　tree　trunks；　walls；　and　palings；　grew　a　great　quantity　of　climbing　Pothos　plants；　with　large　glossy　heart…　shaped　leaves。　These　plants　were　the　resort　of　these　two　exquisite　species；　and　we　captured　a　great　number　of　specimens。　They　are　of　extremely　delicate　texture。　The　wings　are　cream…　coloured；　the　hind　pair　have　several　tail…like　appendages；　and　are　spangled　beneath　as　if　with　silver。　Their　flight　is　very　slow　and　feeble；　they　seek　the　protected　under…surface　of　the　leaves；　and　in　repose　close　their　wings　over　the　back；　so　as　to　expose　the　brilliantly　spotted　under…surface。

I　will　pass　over　the　many　other　orders　and　families　of　insects；　and　proceed　at　once　to　the　ants。　These　were　in　great　numbers　everywhere；　but　I　will　mention　here　only　two　kinds。　We　were　amazed　at　seeing　ants　an　inch　and　a　quarter　in　length；　and　stout　in　proportion；　marching　in　single　file　through　the　thickets。　These　belonged　to　the　species　called　Dinoponera　grandis。　Its　colonies　consist　of　a　small　number　of　individuals；　and　are　established　about　the　roots　of　slender　trees。　It　is　a　stinging　species；　but　the　sting　is　not　so　severe　as　in　many　of　the　smaller　kinds。　There　was　nothing　peculiar　or　attractive　in　the　habits　of　this　giant　among　the　ants。　Another　far　more　interesting　species　was　the　Sauba　（Oecodoma　cephalotes）。　This　ant　is　seen　everywhere　about　the　suburbs；　marching　to　and　fro　in　broad　columns。　From　its　habit　of　despoiling　the　most　valuable　cultivated　trees　of　their　foliage；　it　is　a　great　scourge　to　the　Brazilians。　In　some　districts　it　is　so　abundant　that　agriculture　is　almost　impossible；　and　everywhere　complaints　are　heard　of　the　terrible　pest。

The　workers　of　this　species　are　of　three　orders；　and　vary　in　size　from　two　to　seven　lines；　some　idea　of　them　may　be　obtained　from　the　accompanying　woodcut。　The　true　working…class　of　a　colony　is　formed　by　the　small…sized　order　of　workers；　the　worker…minors　as　they　are　called　（Fig。　I）。　The　two　other　kinds；　whose　functions；　as　we　shall　see；　are　not　yet　properly　understood；　have　enormously　swollen　and　massive　heads；　in　one　（Fig。　2）；　the　head　is　highly　polished；　in　the　other　（Fig。　3）；　it　is　opaque　and　hairy。　The　worker…minors　vary　greatly　in　size；　some　being　double　the　bulk　of　others。　The　entire　body　is　of　very　solid　consistency；　and　of　a　pale　reddish…brown　colour。　The　thorax　or　middle　segment　is　armed　with　three　pairs　of　sharp　spines；　the　head；　also；　has　a　pair　of　similar　spines　proceeding　from　the　cheeks　behind。

In　our　first　walks　we　were　puzzled　to　account　for　large　mounds　of　earth；　of　a　different　colour　from　the　surrounding　soil；　which　were　thrown　up　in　the　plantations　and　woods。　Some　of　them　were　very　extensive；　being　forty　yards　in　circumference；　but　not　more　than　two　feet　in　height。　We　soon　ascertained　that　these　were　the　work　of　the　Saubas；　being　the　outworks；　or　domes；　which　overlie　and　protect　the　entrances　to　their　vast　subterranean　galleries。　On　close　examination；　I　found　the　earth　of　which　they　are　composed　to　consist　of　very　minute　granules；　agglomerated　without　cement；　and　forming　many　rows　of　little　ridges　and　turrets。　The　difference　in　colour　from　the　superficial　soil　of　the　vicinity　is　owing　to　their　being　formed　of　the　undersoil；　brought　up　from　a　considerable　depth。　It　is　very　rarely　that　the　ants　are　seen　at　work　on　these　mounds；　the　entrances　seem　to　be　generally　closed；　only　now　and　then；　when　some　particular　work　is　going　on；　are　the　galleries　opened。　The　entrances　are　small　and　numerous；　in　the　larger　hillocks　it　would　require　a　great　amount　of　excavation　to　get　at　the　main　galleries；　but；　I　succeeded　in　removing　portions　of　the　dome　in　smaller　hillocks；　and　then　I　found　that　the　minor　entrances　converged；　at　the　depth　of　about　two　feet；　into　one　broad；　elaborately…worked　gallery　or　mine；　which　was　four　or　five　inches　in　diameter。

This　habit　of　the　Sauba　ant；　of　clipping　and　carrying　away　immense　quantities　of　leaves；　has　long　been　recorded　in　books　on　natural　history。　When　employed　on　this　work；　their　processions　look　like　a　multitude　of　animated　leaves　on　the　march。　In　some　places　I　found　an　accumulation　of　such　leaves；　all　circular　pieces；　about　the　size　of　a　sixpence；　lying　on　the　pathway；　unattended　by　ants；　and　at　some　distance　from　any　colony。　Such　heaps　are　always　found　to　be　removed　when　the　place　is　revisited　the　next　day。　In　course　of　time　I　had　plenty　of　opportunities　of　seeing　them　at　work。　They　mount　the　tree　in　multitudes；　the　individuals　being　all　worker…minors。　Each　one　places　itself　on　the　surface　of　a　leaf；　and　cuts；　with　its　sharp　scissor…like　jaws；　a　nearly　semicircular　incision　on　the　upper　side；　it　then　takes　the　edge　between　its　jaws；　and　by　a　sharp　jerk　detaches　the　piece。　Sometimes　they　let　the　leaf　drop　to　the　ground；　where　a　little　heap　accumulates；　until　carried　off　by　another　relay　of　workers；　but；　generally；　each　marches　off　with　the　piece　it　has　operated　upon；　and　as　all　take　the　same　road　to　their　colony；　the　path　they　follow　becomes　in　a　short　time　smooth　and　bare；　looking　like　the　impression　of　a　cartwheel　through　the　herbage。

It　is　a　most　interesting　sight　to　see　the　vast　host　of　busy　diminutive　labourers　occupied　on　this　work。　Unfortunately；　they　choose　cultivated　trees　for　their　purpose。　This　ant　is　quite　peculiar　to　Tropical　America；　as　is　the　entire　genus　to　which　it　belongs；　it　sometimes　despoils　the　young　trees　of　species　growing　wild　in　its　native　forests；　but　seems　to　prefer；　when　within　reach；　plants　imported　from　other　countries；　such　as　the　coffee　and　orange　trees。　It　has　not　hitherto　been　shown　satisfactorily　to　what　use　it　applies　the　leaves。　I　discovered　this　only　after　much　time　spent　in　investigation。　The　leaves　are　used　to　thatch　the　domes　which　cover　the　entrances　to　their　subterranean　dwellings；　thereby　protecting　from　the　deluging　rains　the　young　broods　in　the　nests　beneath。　The　larger　mounds；　already　described；　are　so　extensive　that　few　persons　would　attempt　to　remove　them　for　the　purpose　of　examining　their　interior；　but　smaller　hillocks；　covering　other　entrances　to　the　same　system　of　tunnels　and　chambers；　may　be　found　in　sheltered　places；　and　these　are　always　thatched　with　leaves；　mingled　with　granules　of　earth。　The　heavily…laden　workers；　each　carrying　its　segment　of　leaf　vertically；　the　lower　edge　secured　in　its　mandibles；　troop　up　and　cast　their　burdens　on　the　hillock；　another　relay　of　labourers　place　the　leaves　in　position；　covering　them　with　a　layer　of　earthy　granules；　which　are　brought　one　by　one　from　the　soil　beneath。

The　underground　abodes　of　this　wonderful　ant　are　known　to　be　very　extensive。　The　Rev。　Hamlet　Clark　has　related　that　the　Sauba　of　Rio　de　Janeiro；　a　species　closely　allied　to　ours；　has　excavated　a　tunnel　under　the　bed　of　the　river　Parahyba；　at　a　place　where　it　is　broad　as　the　Thames　at　London　Bridge。　At　the　Magoary　Rice　Mills；　near　Para；　these　ants　once　pierced　the　embankment　of　a　large　reservoir；　the　great　body　of　water　which　it　contained　escaped　before　the　damage　could　be　repaired。　In　the　Botanic　Gardens；　at　Para；　an　enterprising　French　gardener　tried　all　he　could　think　of　to　extirpate　the　Sauba。　With　this　object；　he　made　fires　over　some　of　the　main　entrances　to　their　colonies；　and　blew　the　fumes　of　sulphur　down　the　galleries　by　means　of　bellows。　I　saw　the　smoke　issue　from　a　great　number　of　outlets；　one　of　which　was　seventy　yards　distant　from　the　place　where　the　bellows　were　used。　This　shows　how　extensively　the　underground　galleries　are　ramified。

Besides　injuring　and　destroying　young　trees　by　despoiling　them　of　their　foliage；　the　Sauba　ant　is　troublesome　to　the　inhabitants　from　its　habit　of　plundering　the　stores　of　provisions　in　houses　at　night；　for　it　is　even　more　active　by　night　than　in　the　day…　time。　At　first　I　was　inclined　to　discredit　the　stories　of　their　entering　habitations　and　carrying　off　grain　by　grain　the　farinha　or　mandioca　meal；　the　bread　of　the　poorer　classes　of　Brazil。　At　length；　whilst　residing　at　an　Indian　village　on　the　Tapajos；　I　had　ample　proof　of　the　fact。　One　night　my　servant　woke　me　three　or　four　hours　before　sunrise；　by　calling　out　that　the　rats　were　robbing　the　farinha　basketsthe　article　at　that　time　being　scarce　and　dear。　I　got　up；　listened；　and　found　the　noise　was　very　unlike　that　made　by　rats。　So；　I　took　the　light　and　went　into　the　storeroom；　which　was　close　to　my　sleeping…place。　I　there　found　a　broad　column　of　Sauba　ants；　consisting　of　thousands　of　individuals；　as　busy　as　possible；　passing　to　and　fro　between　the　door　and　my　precious　baskets。　Most　of　those　passing　outwards　were　laden　each　with　a　grain　of　farinha；　which　was；　in　some　cases；　larger　and　many　times　heavier　than　the　bodies　of　the　carriers。　Farinha　consists　of　grains　of　similar　size　and　appearance　to　the　tapioca　of　our　shops；　both　are　products　of　the　same　root；　tapioca　being　the　pure　starch；　and　farinha　the　starch　mixed　with　woody　fibre；　the　latter　ingredient　giving　it　a　yellowish　colour。　It　was　amusing　to　see　some　of　the　dwarfs；　the　smallest　members　of　their　family；　staggering　along；　completely　hidden　under　their　load。　The　baskets；　which　were　on　a　high　table；　were　entirely　covered　with　ants；　many　hundreds　of　whom　were　employed　in　snipping　the　dry　leaves　which　served　as　lining。　This　produced　the　rustling　sound　which　had　at　first　disturbed　us。　My　servant　told　me　that　they　would　carry　off　the　whole　contents　of　the　two　baskets　（about　two　bushels）　in　the　course　of　the　night；　if　they　were　not　driven　off；　so　we　tried　to　exterminate　them　by　killing　them　with　our　wooden　clogs。　It　was　impossible；　however；　to　prevent　fresh　hosts　coming　in　as　fast　as　we　killed　their　companions。　They　returned　the　next　night；　and　I　was　then　obliged　to　lay　trains　of　gunpowder　along　their　line；　and　blow　them　up。　This；　repeated　many　times；　at　last　seemed　to　intimidate　them；　for　we　were　free　from　the