a history of science-4-第28部分

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letely　under　subjection。　Dogs　have　been　transported　by　mankind　into　every　part　of　the　world　and　have　submitted　their　action　to　his　entire　direction。　Regulated　in　their　unions　by　the　pleasure　or　caprice　of　their　masters；　the　almost　endless　varieties　of　dogs　differ　from　one　another　in　color；　in　length；　and　abundance　of　hair；　which　is　sometimes　entirely　wanting；　in　their　natural　instincts；　in　size；　which　varies　in　measure　as　one　to　five；　mounting　in　some　instances　to　more　than　a　hundredfold　in　bulk；　in　the　form　of　their　ears；　noses；　and　tails；　in　the　relative　length　of　their　legs；　in　the　progressive　development　of　the　brain；　in　several　of　the　domesticated　varieties　occasioning　alterations　even　in　the　form　of　the　head；　some　of　them　having　long；　slender　muzzles　with　a　flat　forehead；　others　having　short　muzzles　with　a　forehead　convex；　etc。；　insomuch　that　the　apparent　difference　between　a　mastiff　and　a　water…spaniel　and　between　a　greyhound　and　a　pugdog　are　even　more　striking　than　between　almost　any　of　the　wild　species　of　a　genus。　。　。　。　。　。　。　。

It　follows　from　these　observations　that　animals　have　certain　fixed　and　natural　characters　which　resist　the　effects　of　every　kind　of　influence；　whether　proceeding　from　natural　causes　or　human　interference；　and　we　have　not　the　smallest　reason　to　suspect　that　time　has　any　more　effect　on　them　than　climate。

〃I　am　aware　that　some　naturalists　lay　prodigious　stress　upon　the　thousands　which　they　can　call　into　action　by　a　dash　of　their　pens。　In　such　matters；　however；　our　only　way　of　judging　as　to　the　effects　which　may　be　produced　by　a　long　period　of　time　is　by　multiplying；　as　it　were；　such　as　are　produced　by　a　shorter　time。　　With　this　view　I　have　endeavored　to　collect　all　the　ancient　documents　respecting　the　forms　of　animals；　and　there　are　none　equal　to　those　furnished　by　the　Egyptians；　both　in　regard　to　their　antiquity　and　abundance。　They　have　not　only　left　us　representatives　of　animals；　but　even　their　identical　bodies　embalmed　and　preserved　in　the　catacombs。

〃I　have　examined；　with　the　greatest　attention；　the　engraved　figures　of　quadrupeds　and　birds　brought　from　Egypt　to　ancient　Rome；　and　all　these　figures；　one　with　another；　have　a　perfect　resemblance　to　their　intended　objects；　such　as　they　still　are　to…day。

〃From　all　these　established　facts；　there　does　not　seem　to　be　the　smallest　foundation　for　supposing　that　the　new　genera　which　I　have　discovered　or　established　among　extraneous　fossils；　such　as　the　paleoetherium；　anoplotherium；　megalonyx；　mastodon；　pterodactylis；　etc。；　have　ever　been　the　sources　of　any　of　our　present　animals；　which　only　differ　so　far　as　they　are　influenced　by　time　or　climate。　Even　if　it　should　prove　true；　which　I　am　far　from　believing　to　be　the　case；　that　the　fossil　elephants；　rhinoceroses；　elks；　and　bears　do　not　differ　further　from　the　existing　species　of　the　same　genera　than　the　present　races　of　dogs　differ　among　themselves；　this　would　by　no　means　be　a　sufficient　reason　to　conclude　that　they　were　of　the　same　species；　since　the　races　or　varieties　of　dogs　have　been　influenced　by　the　trammels　of　domesticity；　which　those　other　animals　never　did；　and　indeed　never　could；　experience。〃＇3＇


To　Cuvier's　argument　from　the　fixity　of　Egyptian　mummified　birds　and　animals；　as　above　stated；　Lamarck　replied　that　this　proved　nothing　except　that　the　ibis　had　become　perfectly　adapted　to　its　Egyptian　surroundings　in　an　early　day；　historically　speaking；　and　that　the　climatic　and　other　conditions　of　the　Nile　Valley　had　not　since　then　changed。　His　theory；　he　alleged；　provided　for　the　stability　of　species　under　fixed　conditions　quite　as　well　as　for　transmutation　under　varying　conditions。

But；　needless　to　say；　the　popular　verdict　lay　with　Cuvier；　talent　won　for　the　time　against　genius；　and　Lamarck　was　looked　upon　as　an　impious　visionary。　　His　faith　never　wavered；　however。　He　believed　that　he　had　gained　a　true　insight　into　the　processes　of　animate　nature；　and　he　reiterated　his　hypotheses　over　and　over；　particularly　in　the　introduction　to　his　Histoire　Naturelle　des　Animaux　sans　Vertebres；　in　1815；　and　in　his　Systeme　des　Connaissances　Positives　de　l'Homme；　in　1820。　He　lived　on　till　1829；　respected　as　a　naturalist；　but　almost　unrecognized　as　a　prophet。


TENTATIVE　ADVANCES

While　the　names　of　Darwin　and　Goethe；　and　in　particular　that　of　Lamarck；　must　always　stand　out　in　high　relief　in　this　generation　as　the　exponents　of　the　idea　of　transmutation　of　species；　there　are　a　few　others　which　must　not　be　altogether　overlooked　in　this　connection。　　Of　these　the　most　conspicuous　is　that　of　Gottfried　Reinhold　Treviranus；　a　German　naturalist　physician；　professor　of　mathematics　in　the　lyceum　at　Bremen。

It　was　an　interesting　coincidence　that　Treviranus　should　have　published　the　first　volume　of　his　Biologie；　oder　Philosophie　der　lebenden　Natur；　in　which　his　views　on　the　transmutation　of　species　were　expounded；　in　1802；　the　same　twelvemonth　in　which　Lamarck's　first　exposition　of　the　same　doctrine　appeared　in　his　Recherches　sur　l'Organisation　des　Corps　Vivants。　　It　is　singular；　too；　that　Lamarck；　in　his　Hydrogelogie　of　the　same　date；　should　independently　have　suggested　〃biology〃　as　an　appropriate　word　to　express　the　general　science　of　living　things。　It　is　significant　of　the　tendency　of　thought　of　the　time　that　the　need　of　such　a　unifying　word　should　have　presented　itself　simultaneously　to　independent　thinkers　in　different　countries。

That　same　memorable　year；　Lorenz　Oken；　another　philosophical　naturalist；　professor　in　the　University　of　Zurich；　published　the　preliminary　outlines　of　his　Philosophie　der　Natur；　which；　as　developed　through　later　publications；　outlined　a　theory　of　spontaneous　generation　and　of　evolution　of　species。　Thus　it　appears　that　this　idea　was　germinating　in　the　minds　of　several　of　the　ablest　men　of　the　time　during　the　first　decade　of　our　century。　But　the　singular　result　of　their　various　explications　was　to　give　sudden　check　to　that　undercurrent　of　thought　which　for　some　time　had　been　setting　towards　this　conception。　　As　soon　as　it　was　made　clear　whither　the　concession　that　animals　may　be　changed　by　their　environment　must　logically　trend；　the　recoil　from　the　idea　was　instantaneous　and　fervid。　Then　for　a　generation　Cuvier　was　almost　absolutely　dominant；　and　his　verdict　was　generally　considered　final。

There　was；　indeed；　one　naturalist　of　authority　in　France　who　had　the　hardihood　to　stand　out　against　Cuvier　and　his　school；　and　who　was　in　a　position　to　gain　a　hearing；　though　by　no　means　to　divide　the　following。　This　was　Etienne　Geoffroy　Saint…Hilaire；　the　famous　author　of　the　Philosophie　Anatomique；　and　for　many　years　the　colleague　of　Lamarck　at　the　Jardin　des　Plantes。　　Like　Goethe；　Geoffroy　was　pre…eminently　an　anatomist；　and；　like　the　great　German；　he　had　early　been　impressed　with　the　resemblances　between　the　analogous　organs　of　different　classes　of　beings。　　He　conceived　the　idea　that　an　absolute　unity　of　type　prevails　throughout　organic　nature　as　regards　each　set　of　organs。　Out　of　this　idea　grew　his　gradually　formed　belief　that　similarity　of　structure　might　imply　identity　of　originthat；　in　short；　one　species　of　animal　might　have　developed　from　another。

Geoffroy's　grasp　of　this　idea　of　transmutation　was　by　no　means　so　complete　as　that　of　Lamarck；　and　he　seems　never　to　have　fully　determined　in　his　own　mind　just　what　might　be　the　limits　of　such　development　of　species。　Certainly　he　nowhere　includes　all　organic　creatures　in　one　line　of　descent；　as　Lamarck　had　done；　nevertheless；　he　held　tenaciously　to　the　truth　as　he　saw　it；　in　open　opposition　to　Cuvier；　with　whom　he　held　a　memorable　debate　at　the　Academy　of　Sciences　in　1830the　debate　which　so　aroused　the　interest　and　enthusiasm　of　Goethe；　but　which；　in　the　opinion　of　nearly　every　one　else；　resulted　in　crushing　defeat　for　Geoffrey；　and　brilliant；　seemingly　final；　victory　for　the　advocate　of　special　creation　and　the　fixity　of　species。

With　that　all　ardent　controversy　over　the　subject　seemed　to　end；　and　for　just　a　quarter　of　a　century　to　come　there　was　published　but　a　single　argument　for　transmutation　of　species　which　attracted　any　general　attention　whatever。　　This　oasis　in　a　desert　generation　was　a　little　book　called　Vestiges　of　the　Natural　History　of　Creation；　which　appeared　anonymously　in　England　in　1844；　and　which　passed　through　numerous　editions；　and　was　the　subject　of　no　end　of　abusive　and　derisive　comment。　This　book；　the　authorship　of　which　remained　for　forty　years　a　secret；　is　now　conceded　to　have　been　the　work　of　Robert　Chambers；　the　well…known　English　author　and　publisher。　　The　book　itself　is　remarkable　as　being　an　avowed　and　unequivocal　exposition　of　a　general　doctrine　of　evolution；　its　view　being　as　radical　and　comprehensive　as　that　of　Lamarck　himself。　But　it　was　a　resume　of　earlier　efforts　rather　than　a　new　departure；　to　say　nothing　of　its　technical　shortcomings；　which　may　best　be　illustrated　by　a　quotation。

〃The　whole　question；〃　says　Chambers；　〃stands　thus：　　For　the　theory　of　universal　orderthat　is；　order　as　presiding　in　both　the　origin　and　administration　of　the　worldwe　have　the　testimony　of　a　vast　number　of　facts　in　nature；　and　this　one　in　additionthat　whatever　is　left　from　the　domain　of　ignorance；　and　made　undoubted　matter　of