the naturalist on the river amazons-第49部分

按键盘上方向键 ← 或 → 可快速上下翻页，按键盘上的 Enter 键可回到本书目录页，按键盘上方向键 ↑ 可回到本页顶部！
————未阅读完？加入书签已便下次继续阅读！


nks　of　the　Upper　Amazons；　sometimes　excavates　its　mine　solitarily　on　sand…　banks　recently　laid　bare　in　the　middle　of　the　river；　and　closes　the　orifice　before　going　in　search　of　prey。　In　these　cases　the　insect　has　to　make　a　journey　of　at　least　half　a　mile　to　procure　the　kind　of　fly；　the　Motuca　（Hadrus　lepidotus）；　with　which　it　provisions　its　cell。　I　often　noticed　it　to　take　a　few　turns　in　the　air　round　the　place　before　starting；　on　its　return　it　made　without　hesitation　straight　for　the　closed　mouth　of　the　mine。　I　was　convinced　that　the　insects　noted　the　bearings　of　their　nests　and　the　direction　they　took　in　flying　from　them。　The　proceeding　in　this　and　similar　cases　（I　have　read　of　something　analogous　having　been　noticed　in　hive　bees）　seems　to　be　a　mental　act　of　the　same　nature　as　that　which　takes　place　in　ourselves　when　recognising　a　locality。　The　senses；　however；　must　be　immeasurably　more　keen　and　the　mental　operation　much　more　certain　in　them　than　it　is　in　man；　for　to　my　eye　there　was　absolutely　no　landmark　on　the　even　surface　of　sand　which　could　serve　as　guide；　and　the　borders　of　the　forest　were　not　nearer　than　half　a　mile。　The　action　of　the　wasp　would　be　said　to　be　instinctive；　but　it　seems　plain　that　the　instinct　is　no　mysterious　and　unintelligible　agent；　but　a　mental　process　in　each　individual；　differing　from　the　same　in　man　only　by　its　unerring　certainty。　The　mind　of　the　insect　appears　to　be　so　constituted　that　the　impression　of　external　objects　or　the　want　felt；　causes　it　to　act　with　a　precision　which　seems　to　us　like　that　of　a　machine　constructed　to　move　in　a　certain　given　way。　I　have　noticed　in　Indian　boys　a　sense　of　locality　almost　as　keen　as　that　possessed　by　the　sand…　wasp。　An　old　Portuguese　and　myself；　accompanied　by　a　young　lad　about　ten　years　of　age；　were　once　lost　in　the　forest　in　a　most　solitary　place　on　the　banks　of　the　main　river。　Our　case　seemed　hopeless；　and　it　did　not　for　some　time　occur　to　us　to　consult　our　little　companion；　who　had　been　playing　with　his　bow　and　arrow　all　the　way　while　we　were　hunting；　apparently　taking　no　note　of　the　route。　When　asked；　however；　he　pointed　out；　in　a　moment；　the　right　direction　of　our　canoe。　He　could　not　explain　how　he　knew；　I　believe　he　had　noted　the　course　we　had　taken　almost　unconsciously；　the　sense　of　locality　in　his　case　seemed　instinctive。

The　Monedula　signata　is　a　good　friend　to　travellers　in　those　parts　of　the　Amazons　which　are　infested　by　the　blood…thirsty　Motuca。　I　first　noticed　its　habit　of　preying　on　this　fly　one　day　when　we　landed　to　make　our　fire　and　dine　on　the　borders　of　the　forest　adjoining　a　sand…bank。　The　insect　is　as　large　as　a　hornet；　and　has　a　most　waspish　appearance。　I　was　rather　startled　when　one　out　of　the　flock　which　was　hovering　about　us　flew　straight　at　my　face　it　had　espied　a　Motuca　on　my　neck　and　was　thus　pouncing　upon　it。　It　seizes　the　fly　not　with　its　jaws；　but　with　its　fore　and　middle　feet；　and　carries　it　off　tightly　held　to　its　breast。　Wherever　the　traveller　lands　on　the　Upper　Amazons　in　the　neighbourhood　of　a　sand…bank　he　is　sure　to　be　attended　by　one　or　more　of　these　useful　vermin…killers。

The　bay　of　Mapiri　was　the　limit　of　my　day　excursions　by　the　river…side　to　the　west　of　Santarem。　A　person　may　travel；　however；　on　foot；　as　Indians　frequently　do；　in　the　dry　season　for　fifty　or　sixty　miles　along　the　broad　clean　sandy　beaches　of　the　Tapajos。　The　only　obstacles　are　the　rivulets；　most　of　which　are　fordable　when　the　waters　are　low。　To　the　east　my　rambles　extended　to　the　banks　of　the　Mahica　inlet。　This　enters　the　Amazons　about　three　miles　below　Santarem；　where　the　clear　stream　of　the　Tapajos　begins　to　be　discoloured　by　the　turbid　waters　of　the　main　river。　The　Mahica　has　a　broad　margin　of　rich　level　pasture；　limited　on　each　side　by　the　straight；　tall　hedge　of　forest。　On　the　Santarem　side　it　is　skirted　by　high　wooded　ridges。　A　landscape　of　this　description　always　produced　in　me　an　impression　of　sadness　and　loneliness　which　the　luxuriant　virgin　forests　that　closely　hedge　in　most　of　the　by…waters　of　the　Amazons　never　created。　The　pastures　are　destitute　of　flowers；　and　also　of　animal　life；　with　the　exception　of　a　few　small　plain…coloured　birds　and　solitary　Caracara　eagles　whining　from　the　topmost　branches　of　dead　trees　on　the　forest　borders。　A　few　settlers　have　built　their　palm…　thatched　and　mud…walled　huts　on　the　banks　of　the　Mahica；　and　occupy　themselves　chiefly　in　tending　small　herds　of　cattle。　They　seemed　to　be　all　wretchedly　poor。　The　oxen　however；　though　small；　were　sleek　and　fat；　and　the　district　most　promising　for　agricultural　and　pastoral　employments。　In　the　wet　season　the　waters　gradually　rise　and　cover　the　meadows；　but　there　is　plenty　of　room　for　the　removal　of　the　cattle　to　higher　ground。　The　lazy　and　ignorant　people　seem　totally　unable　to　profit　by　these　advantages。　The　houses　have　no　gardens　or　plantations　near　them。　I　was　told　it　was　useless　to　plant　anything；　because　the　cattle　devoured　the　young　shoots。　In　this　country；　grazing　and　planting　are　very　rarely　carried　on　together；　for　the　people　seem　to　have　no　notion　of　enclosing　patches　of　ground　for　cultivation。　They　say　it　is　too　much　trouble　to　make　enclosures。　The　construction　of　a　durable　fence　is　certainly　a　difficult　matter；　for　it　is　only　two　or　three　kinds　of　tree　which　will　serve　the　purpose　in　being　free　from　the　attacks　of　insects；　and　these　are　scattered　far　and　wide　through　the　woods。

Although　the　meadows　were　unproductive　ground　to　a　naturalist；　the　woods　on　their　borders　teemed　with　life；　the　number　and　variety　of　curious　insects　of　all　orders　which　occurred　here　was　quite　wonderful。　The　belt　of　forest　was　intersected　by　numerous　pathways　leading　from　one　settler's　house　to　another。　The　ground　was　moist；　but　the　trees　were　not　so　lofty　or　their　crowns　so　densely　packed　together　as　in　other　parts；　the　sun's　light　and　heat；　therefore；　had　freer　access　to　the　soil；　and　the　underwood　was　much　more　diversified　than　in　the　virgin　forest。　I　never　saw　so　many　kinds　of　dwarf　palms　together　as　here；　pretty　miniature　species；　some　not　more　than　five　feet　high；　and　bearing　little　clusters　of　round　fruit　not　larger　than　a　good　bunch　of　currants。　A　few　of　the　forest　trees　had　the　size　and　strongly…branched　figures　of　our　oaks；　and　a　similar　bark。　One　noble　palm　grew　here　in　great　abundance；　and　gave　a　distinctive　character　to　the　district。　This　was　the　Oenocarpus　distichus；　one　of　the　kinds　called　Bacaba　by　the　natives。　It　grows　to　a　height　of　forty　to　fifty　feet。　The　crown　is　of　a　lustrous　dark…green　colour；　and　of　a　singularly　flattened　or　compressed　shape；　the　leaves　being　arranged　on　each　side　in　nearly　the　same　plane。　When　I　first　saw　this　tree　on　the　campos；　where　the　east　wind　blows　with　great　force　night　and　day　for　several　months；　I　thought　the　shape　of　the　crown　was　due　to　the　leaves　being　prevented　from　radiating　equally　by　the　constant　action　of　the　breezes。　But　the　plane　of　growth　is　not　always　in　the　direction　of　the　wind；　and　the　crown　has　the　same　shape　when　the　tree　grows　in　the　sheltered　woods。　The　fruit　of　this　fine　palm　ripens　towards　the　end　of　the　year；　and　is　much　esteemed　by　the　natives；　who　manufacture　a　pleasant　drink　from　it　similar　to　the　assai　described　in　a　former　chapter；　by　rubbing　off　the　coat　of　pulp　from　the　nuts；　and　mixing　it　with　water。　A　bunch　of　fruit　weighs　thirty　or　forty　pounds。　The　beverage　has　a　milky　appearance；　and　an　agreeable　nutty　flavour。　The　tree　is　very　difficult　to　climb；　on　account　of　the　smoothness　of　its　stein；　consequently　the　natives；　whenever　they　want　a　bunch　of　fruit　for　a　bowl　of　Bacaba；　cut　down　and　thus　destroy　a　tree　which　has　taken　a　score　or　two　of　years　to　grow；　in　order　to　get　at　it。

In　the　lower　part　of　the　Mahica　woods；　towards　the　river；　there　is　a　bed　of　stiff　white　clay；　which　supplies　the　people　of　Santarem　with　material　for　the　manufacture　of　coarse　pottery　and　cooking　utensils：　all　the　kettles；　saucepans；　mandioca　ovens；　coffee…pots；　washing…vessels；　and　so　forth；　of　the　poorer　classes；　throughout　the　country；　are　made　of　this　same　plastic　clay；　which　occurs　at　short　intervals　over　the　whole　surface　of　the；　Amazons　valley；　from　the　neighbourhood　of　Para　to　within　the　Peruvian　borders；　and　forms　part　of　the　great　Tabatinga　marl　deposit。　To　enable　the　vessels　to　stand　the　fire；　the　bark　of　a　certain　tree；　called　Caraipe；　is　burned　and　mixed　with　the　clay；　which　gives　tenacity　to　the　ware。　Caraipe　is　an　article　of　commerce　being　sold　and　packed　in　baskets　at　the　shops　in　most　of　the　towns。　The　shallow　pits；　excavated　in　the　marly　soil　at　Mahica；　were　very　attractive　to　many　kinds　of　mason　bees　and　wasps；　who　made　use　of　the　clay　to　build　their　nests　withso　we　have　here　another　example　of　the　curious　analogy　that　exists　between　the　arts　of　insects　and　those　of　man。　I　spent　many　an　hour　watching　their　proceedings；　a　short　account　of　the　habits　of　some　of　these　busy　creatures　may　be　interesting。

The　most　conspicuous　was　a　large　yellow　and　black　wasp；　with　a　remarkably　long　and　narrow　waist；　the　Pelopaeus　fistularis。　This　species　collected　the　clay　in　little　round　pellets；　which　it　carried　off；　after　rolling　them　into　a　convenient　shape；　in　its　mouth。　It　came　straight　to　the　pit　with　a　loud　hum；　and；　on　alighting；　lost　not　a　moment　in　beginning　to　work　finishing　the　kneading　of　its　little　load　in　two　or　three　minutes。　The　nest　of　this　wasp　is　shaped　like　a　pouch；　two　inches　in　length；　and　is　attached　to　a　branch　or　other　projecting　object。　One　of　these　restless　artificers　once　began　to　build　on　the　handle　of　a　chest　in　the　cabin　of　my　canoe；　when　we　were　stationary　at　a　place　for　several　days。　It　was　so　intent　on　its　work　that　it　allowed　me　to　inspect　the　movements　of　its　mouth　with　a　lens　while　it　was　laying　on　the　mortar。　Every　fresh　pellet　was　brought　in　with　a　triumphant　song；　which　changed　to　a　cheerful　busy　hum　when　it　alighted　and　began　to　work。　The　little　ball　of　moist　clay　was　laid　on　the　edge　of　the　cell；　and　then　spread　out　around　the　circular　rim　by　means　of　the　lower　lip　guided　by　the　mandibles。　The　insect　placed　itself　astride　over　the　rim　to　work；　and；　on　finishing　each　addition　to　the　structure；　took　a　turn　round；　patting　the　sides　with　its　feet　inside　and　out　before　flying　off　to　gather　a　fresh