the origin of species(物种起源)-第45节

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lanes　of　imaginary　intersection　between　the　basins　on　the　opposite　sides　of　the　ridge　of　wax。　In　parts；　only　little　bits；　in　other　parts；　large　portions　of　a　rhombic　plate　had　been　left　between　the　opposed　basins；　but　the　work；　from　the　unnatural　state　of　things；　had　not　been　neatly　performed。　The　bees　must　have　worked　at　very　nearly　the　same　rate　on　the　opposite　side　of　the　ridge　of　vermilion　wax；　as　they　circularly　gnawed　away　and　deepened　the　basins　on　both　sides；　in　order　to　have　succeeded　in　thus　leaving　flat　plates　between　the　basins；　by　stopping　work　along　the　intermediate　planes　or　planes　of　intersection。　
Considering　how　flexible　thin　wax　is；　I　do　not　see　that　there　is　any　difficulty　in　the　bees；　whilst　at　work　on　the　two　sides　of　a　strip　of　wax；　perceiving　when　they　have　gnawed　the　wax　away　to　the　proper　thinness；　and　then　stopping　their　work。　In　ordinary　combs　it　has　appeared　to　me　that　the　bees　do　not　always　succeed　in　working　at　exactly　the　same　rate　from　the　opposite　sides；　for　I　have　noticed　half…completed　rhombs　at　the　base　of　a　just…commenced　cell；　which　were　slightly　concave　on　one　side；　where　I　suppose　that　the　bees　had　excavated　too　quickly；　and　convex　on　the　opposed　side；　where　the　bees　had　worked　less　quickly。　In　one　well…marked　instance；　I　put　the　comb　back　into　the　hive　and　allowed　the　bees　to　go　on　working　for　a　short　time　and　again　examined　the　cell；　and　I　found　that　the　rhombic　plate　had　been　completed；　and　had　become　perfectly　flat：　it　was　absolutely　impossible；　from　the　extreme　thinness　of　the　little　rhombic　plate；　that　they　could　have　affected　this　by　gnawing　away　the　convex　side；　and　I　suspect　that　the　bees　in　such　cases　stand　in　the　opposed　cells　and　push　and　bend　the　ductile　and　warm　wax　（which　as　I　have　tried　is　easily　done）　into　its　proper　intermediate　plane；　and　thus　flatten　it。　
From　the　experiment　of　the　ridge　of　vermilion　wax；　we　can　clearly　see　that　if　the　bees　were　to　build　for　themselves　a　thin　wall　of　wax；　they　could　make　their　cells　of　the　proper　shape；　by　standing　at　the　proper　distance　from　each　other；　by　excavating　at　the　same　rate；　and　by　endeavouring　to　make　equal　spherical　hollows；　but　never　allowing　the　spheres　to　break　into　each　other。　Now　bees；　as　may　be　clearly　seen　by　examining　the　edge　of　a　growing　comb；　do　make　a　rough；　circumferential　wall　or　rim　all　round　the　comb；　and　they　gnaw　into　this　from　the　opposite　sides；　always　working　circularly　as　they　deepen　each　cell。　They　do　not　make　the　whole　three…sided　pyramidal　base　of　any　one　cell　at　the　same　time；　but　only　the　one　rhombic　plate　which　stands　on　the　extreme　growing　margin；　or　the　two　plates；　as　the　case　may　be；　and　they　never　complete　the　upper　edges　of　the　rhombic　plates；　until　the　hexagonal　walls　are　commenced。　Some　of　these　statements　differ　from　those　made　by　the　justly　celebrated　elder　Huber；　but　I　am　convinced　of　their　accuracy；　and　if　I　had　space；　I　could　show　that　they　are　conformable　with　my　theory。　
Huber's　statement　that　the　very　first　cell　is　excavated　out　of　a　little　parallel…sided　wall　of　wax；　is　not；　as　far　as　I　have　seen；　strictly　correct；　the　first　commencement　having　always　been　a　little　hood　of　wax；　but　I　will　not　here　enter　on　these　details。　We　see　how　important　a　part　excavation　plays　in　the　construction　of　the　cells；　but　it　would　be　a　great　error　to　suppose　that　the　bees　cannot　build　up　a　rough　wall　of　wax　in　the　proper　position　that　is；　along　the　plane　of　intersection　between　two　adjoining　spheres。　I　have　several　specimens　showing　clearly　that　they　can　do　this。　Even　in　the　rude　circumferential　rim　or　wall　of　wax　round　a　growing　comb；　flexures　may　sometimes　be　observed；　corresponding　in　position　to　the　planes　of　the　rhombic　basal　plates　of　future　cells。　But　the　rough　wall　of　wax　has　in　every　case　to　be　finished　off；　by　being　largely　gnawed　away　on　both　sides。　The　manner　in　which　the　bees　build　is　curious；　they　always　make　the　first　rough　wall　from　ten　to　twenty　times　thicker　than　the　excessively　thin　finished　wall　of　the　cell；　which　will　ultimately　be　left。　We　shall　understand　how　they　work；　by　supposing　masons　first　to　pile　up　a　broad　ridge　of　cement；　and　then　to　begin　cutting　it　away　equally　on　both　sides　near　the　ground；　till　a　smooth；　very　thin　wall　is　left　in　the　middle；　the　masons　always　piling　up　the　cut…away　cement；　and　adding　fresh　cement；　on　the　summit　of　the　ridge。　We　shall　thus　have　a　thin　wall　steadily　growing　upward；　but　always　crowned　by　a　gigantic　coping。　From　all　the　cells；　both　those　just　commenced　and　those　completed；　being　thus　crowned　by　a　strong　coping　of　wax；　the　bees　can　cluster　and　crawl　over　the　comb　without　injuring　the　delicate　hexagonal　walls；　which　are　only　about　one　four…hundredth　of　an　inch　in　thickness；　the　plates　of　the　pyramidal　basis　being　about　twice　as　thick。　By　this　singular　manner　of　building；　strength　is　continually　given　to　the　comb；　with　the　utmost　ultimate　economy　of　wax。　
It　seems　at　first　to　add　to　the　difficulty　of　understanding　how　the　cells　are　made；　that　a　multitude　of　bees　all　work　together；　one　bee　after　working　a　short　time　at　one　cell　going　to　another；　so　that；　as　Huber　has　stated；　a　score　of　individuals　work　even　at　the　commencement　of　the　first　cell。　I　was　able　practically　to　show　this　fact；　by　covering　the　edges　of　the　hexagonal　walls　of　a　single　cell；　or　the　extreme　margin　of　the　circumferential　rim　of　a　growing　comb；　with　an　extremely　thin　layer　of　melted　vermilion　wax；　and　I　invariably　found　that　the　colour　was　most　delicately　diffused　by　the　bees　as　delicately　as　a　painter　could　have　done　with　his　brush　by　atoms　of　the　coloured　wax　having　been　taken　from　the　spot　on　which　it　had　been　placed；　and　worked　into　the　growing　edges　of　the　cells　all　round。　The　work　of　construction　seems　to　be　a　sort　of　balance　struck　between　many　bees；　all　instinctively　standing　at　the　same　relative　distance　from　each　other；　all　trying　to　sweep　equal　spheres；　and　then　building　up；　or　leaving　ungnawed；　the　planes　of　intersection　between　these　spheres。　It　was　really　curious　to　note　in　cases　of　difficulty；　as　when　two　pieces　of　comb　met　at　an　angle；　how　often　the　bees　would　entirely　pull　down　and　rebuild　in　different　ways　the　same　cell；　sometimes　recurring　to　a　shape　which　they　had　at　first　rejected。　
When　bees　have　a　place　on　which　they　can　stand　in　their　proper　positions　for　working；　for　instance；　on　a　slip　of　wood；　placed　directly　under　the　middle　of　a　comb　growing　downwards　so　that　the　comb　has　to　be　built　over　one　face　of　the　slip　in　this　case　the　bees　can　lay　the　foundations　of　one　wall　of　a　new　hexagon；　in　its　strictly　proper　place；　projecting　beyond　the　other　completed　cells。　It　suffices　that　the　bees　should　be　enabled　to　stand　at　their　proper　relative　distances　from　each　other　and　from　the　walls　of　the　last　completed　cells；　and　then；　by　striking　imaginary　spheres；　they　can　build　up　a　wall　intermediate　between　two　adjoining　spheres；　but；　as　far　as　I　have　seen；　they　never　gnaw　away　and　finish　off　the　angles　of　a　cell　till　a　large　part　both　of　that　cell　and　of　the　adjoining　cells　has　been　built。　This　capacity　in　bees　of　laying　down　under　certain　circumstances　a　rough　wall　in　its　proper　place　between　two　just…commenced　cells；　is　important；　as　it　bears　on　a　fact；　which　seems　at　first　quite　subversive　of　the　foregoing　theory；　namely；　that　the　cells　on　the　extreme　margin　of　wasp…combs　are　sometimes　strictly　hexagonal；　but　I　have　not　space　here　to　enter　on　this　subject。　Nor　does　there　seem　to　me　any　great　difficulty　in　a　single　insect　（as　in　the　case　of　a　queen…wasp）　making　hexagonal　cells；　if　she　work　alternately　on　the　inside　and　outside　of　two　or　three　cells　commenced　at　the　same　time；　always　standing　at　the　proper　relative　distance　from　the　parts　of　the　cells　just　begun；　sweeping　spheres　or　cylinders；　and　building　up　intermediate　planes。　It　is　even　conceivable　that　an　insect　might；　by　fixing　on　a　point　at　which　to　commence　a　cell；　and　then　moving　outside；　first　to　one　point；　and　then　to　five　other　points；　at　the　proper　relative　distances　from　the　central　point　and　from　each　other；　strike　the　planes　of　intersection；　and　so　make　an　isolated　hexagon：　but　I　am　not　aware　that　any　such　case　has　been　observed；　nor　would　any　good　be　derived　from　a　single　hexagon　being　built；　as　in　its　construction　more　materials　would　be　required　than　for　a　cylinder。　
As　natural　selection　acts　only　by　the　accumulation　of　slight　modifications　of　structure　or　instinct；　each　profitable　to　the　individual　under　its　conditions　of　life；　it　may　reasonably　be　asked；　how　a　long　and　graduated　succession　of　modified　architectural　instincts；　all　tending　towards　the　present　perfect　plan　of　construction；　could　have　profited　the　progenitors　of　the　hive…bee？　I　think　the　answer　is　not　difficult：　it　is　known　that　bees　are　often　hard　pressed　to　get　sufficient　nectar；　and　I　am　informed　by　Mr。　Tegetmeier　that　it　has　been　experimentally　found　that　no　less　than　from　twelve　to　fifteen　pounds　of　dry　sugar　are　consumed　by　a　hive　of　bees　for　the　secretion　of　each　pound　of　wax；　so　that　a　prodigious　quantity　of　fluid　nectar　must　be　collected　and　consumed　by　the　bees　in　a　hive　for　the　secretion　of　the　wax　necessary　for　the　construction　of　their　combs。　Moreover；　many　bees　have　to　remain　idle　for　many　days　during　the　proc