on the method of zadig-第3部分

快捷操作: 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! 如果本书没有阅读完，想下次继续接着阅读，可使用上方 "收藏到我的浏览器" 功能 和 "加入书签" 功能！



is　familiar　with　palaeontology；　none　is　more　suitable　than　the

case　of　the　so…called　Belemnites。　In　the　early　days　of

the　study　of　fossils；　this　name　was　given　to　certain　elongated

stony　bodies；　ending　at　one　extremity　in　a　conical　point；　and

truncated　at　the　other；　which　were　commonly　reputed　to　be

thunderbolts；　and　as　such　to　have　descended　from　the　sky。

They　are　common　enough　in　some　parts　of　England；　and；　in　the

condition　in　which　they　are　ordinarily　found；　it　might　be

difficult　to　give　satisfactory　reasons　for　denying　them　to　be

merely　mineral　bodies。



They　appear；　in　fact；　to　consist　of　nothing　but　concentric

layers　of　carbonate　of　lime；　disposed　in　subcrystalline　fibres；

or　prisms；　perpendicular　to　the　layers。　Among　a　great　number　of

specimens　of　these　Belemnites；　however；　it　was　soon　observed

that　some　showed　a　conical　cavity　at　the　blunt　end；　and；　in

still　better　preserved　specimens；　this　cavity　appeared　to　be

divided　into　chambers　by　delicate　saucer…shaped　partitions；

situated　at　regular　intervals　one　above　the　other。　Now　there　is

no　mineral　body　which　presents　any　structure　comparable　to　this；

and　the　conclusion　suggested　itself　that　the　Belemnites　must　be

the　effects　of　causes　other　than　those　which　are　at　work　in

inorganic　nature。　On　close　examination；　the　saucer…shaped

partitions　were　proved　to　be　all　perforated　at　one　point；　and

the　perforations　being　situated　exactly　in　the　same　line；　the

chambers　were　seen　to　be　traversed　by　a　canal；　or

siphuncle；　which　thus　connected　the　smallest　or　aphical

chamber　with　the　largest。　There　is　nothing　like　this　in　the

vegetable　world；　but　an　exactly　corresponding　structure　is　met

with　in　the　shells　of　two　kinds　of　existing　animals；　the　pearly

Nautilus　and　the　Spirula；　and　only　in　them。　These

animals　belong　to　the　same　divisionthe　Cephalopodaas

the　cuttle…fish；　the　squid；　and　the　octopus。　But　they　are　the

only　existing　members　of　the　group　which　possess　chambered；

siphunculated　shells；　and　it　is　utterly　impossible　to　trace　any

physiological　connection　between　the　very　peculiar　structural

characters　of　a　cephalopod　and　the　presence　of　a　chambered

shell。　In　fact；　the　squid　has；　instead　of　any　such　shell；　a

horny　〃pen；〃　the　cuttlefish　has　the　so…called　〃cuttle…bone；〃　and

the　octopus　has　no　shell；　or；　at　most；　a　mere　rudiment　of　one。



Nevertheless；　seeing　that　there　is　nothing　in　nature　at　all　like

the　chambered　shell　of　the　Belemnite；　except　the　shells　of　the

Nautilus　and　of　the　Spirula；　it　was　legitimate　to

prophesy　that　the　animal　from　which　the　fossil　proceeded　must

have　belonged　to　the　group　of　the　Cephalopoda。

Nautilus　and　Spirula　are　both　very　rare　animals；

but　the　progress　of　investigation　brought　to　light　the　singular

fact；　that；　though　each　has　the　characteristic　cephalopodous

organisation；　it　is　very　different　from　the　other。　The　shell　of

Nautilus　is　external；　that　of　Spirula　internal；

Nautilus　has　four　gills；　Spirula　two；

Nautilus　has　multitudinous　tentacles；　Spirula　has

only　ten　arms　beset　with　horny…rimmed　suckers；　Spirula；

like　the　squids　and　cuttle…fishes；　which　it　closely　resembles；

has　a　bag　of　ink　which　it　squirts　out　to　cover　its　retreat　when

alarmed；　Nautilus　has　none。



No　amount　of　physiological　reasoning　could　enable　any　one　to　say

whether　the　animal　which　fabricated　the　Belemnite　was　more　like

Nautilus；　or　more　like　Spirula。　But　the　accidental

discovery　of　Belemnites　in　due　connection　with　black　elongated

masses　which　were：　certainly　fossilised　ink…bags；　inasmuch　as

the　ink　could　be　ground　up　and　used　for　painting　as　well　as　if

it　were　recent　sepia；　settled　the　question；　and　it　became

perfectly　safe　to　prophesy　that　the　creature　which　fabricated

the　Belemnite　was　a　two…gilled　cephalopod　with　suckers　on　its

arms；　and　with　all　the　other　essential　features　of　our　living

squids；　cuttle…fishes；　and　Spirulae。　The　palaeontologist

was；　by　this　time；　able　to　speak　as　confidently　about　the　animal

of　the　Belemnite；　as　Zadig　was　respecting　the　queen's　spaniel。

He　could　give　a　very　fair　description　of　its　external

appearance；　and　even　enter　pretty　fully　into　the　details　of　its

internal　organisation；　and　yet　could　declare　that　neither　he；

nor　any　one　else；　had　ever　seen　one。　And　as　the　queen's　spaniel

was　found；　so　happily　has　the　animal　of　the　Belemnite；　a　few

exceptionally　preserved　specimens　have　been　discovered；　which

completely　verify　the　retrospective　prophecy　of　those　who

interpreted　the　facts　of　the　case　by　due　application　of　the

method　of　Zadig。　



These　Belemnites　flourished　in　prodigious　abundance　in　the　seas

of　the　mesozoic；　or　secondary；　age　of　the　world's　geological

history；　but　no　trace　of　them　has　been　found　in　any　of　the

tertiary　deposits；　and　they　appear　to　have　died　out　towards　the

close　of　the　mesozoic　epoch。　The　method　of　Zadig；　therefore；

applies　in　full　force　to　the　events　of　a　period　which　is

immeasurably　remote；　which　long　preceded　the　origin　of　the　most

conspicuous　mountain　masses　of　the　present　world；　and　the

deposition；　at　the　bottom　of　the　ocean；　of　the　rocks　which　form

the　greater　part　of　the　soil　of　our　present　continents。

The　Euphrates　itself；　at　the　mouth　of　which　Oannes　landed；　is　a

thing　of　yesterday　compared　with　a　Belemnite；　and　even　the

liberal　chronology　of　magian　cosmogony　fixes　the　beginning　of

the　world　only　at　a　time　when　other　applications　of　Zadig's

method　afford　convincing　evidence　that；　could　we　have　been　there

to　see；　things　would　have　looked　very　much　as　they　do　now。

Truly　the　magi　were　wise　in　their　generation；　they　foresaw

rightly　that　this　pestilent　application　of　the　principles　of

common　sense；　inaugurated　by　Zadig；　would　be　their　ruin。



But　it　may　be　said　that　the　method　of　Zadig；　which　is　simple

reasoning　from　analogy；　does　not　account　for　the　most　striking

feats　of　modern　palaeontologythe　reconstruction　of　entire

animals　from　a　tooth　or　perhaps　a　fragment　of　a　bone；　and　it　may

be　justly　urged　that　Cuvier；　the　great　master　of　this　kind　of

investigation；　gave　a　very　different　account　of　the　process

which　yielded　such　remarkable　results。



Cuvier　is　not　the　first　man　of　ability　who　has　failed　to　make

his　own　mental　processes　clear　to　himself；　and　he　will　not　be

the　last。　The　matter　can　be　easily　tested。　Search　the　eight

volumes　of　the　〃Recherches　sur　les　Ossemens　Fossiles〃　from　cover

to　cover；　and　nothing　but　the　application　of　the　method　of　Zadig

will　be　found　in　the　arguments　by　which　a　fragment　of　a　skeleton

is　made　to　reveal　the　characters　of　the　animal　to　which

it　belonged。



There　is　one　well…known　case　which　may　represent　all。　It　is　an

excellent　illustration　of　Cuvier's　sagacity；　and　he　evidently

takes　some　pride　in　telling　his　story　about　it。　A　split　slab　of

stone　arrived　from　the　quarries　of　Montmartre；　the　two　halves　of

which　contained　the　greater　part　of　the　skeleton　of　a　small

animal。　On　careful　examinations　of　the　characters　of　the　teeth

and　of　the　lower　jaw；　which　happened　to　be　exposed；　Cuvier

assured　himself　that　they　presented　such　a　very　close

resemblance　to　the　corresponding　parts　in　the　living　opossums

that　he　at　once　assigned　the　fossil　to　that　genus。



Now　the　opossums　are　unlike　most　mammals　in　that　they　possess

two　bones　attached　to　the　fore　part　of　the　pelvis；　which　are

commonly　called　〃marsupial　bones。〃　The　name　is　a　misnomer；

originally　conferred　because　it　was　thought　that　these　bones

have　something　to　do　with　the　support　of　the　pouch；　or

marsupium；　with　which　some；　but　not　all；　of　the　opossums　are

provided。　As　a　matter　of　fact；　they　have　nothing　to　do　with　the

support　of　the　pouch；　and　they　exist　as　much　in　those　opossums

which　have　no　pouches　as　in　those　which　possess　them。　In　truth；

no　one　knows　what　the　use　of　these　bones　may　be；　nor　has　any

valid　theory　of　their　physiological　import　yet　been　suggested。

And　if　we　have　no　knowledge　of　the　physiological　importance　of

the　bones　themselves；　it　is　obviously　absurd　to　pretend　that　we

are　able　to　give　physiological　reasons　why　the　presence　of　these

bones　is　associated　with　certain　peculiarities　of　the　teeth　and

of　the　jaws。　If　any　one　knows　why　four　molar　teeth　and　an

inflected　angle　of　the　jaw　are　very　generally　found　along　with

marsupial　bones；　he　has　not　yet　communicated　that　knowledge　to

the　world。



If；　however；　Zadig　was　right　in　concluding　from　the　likeness　of

the　hoof…prints　which　he　observed　to　be　a　horse's　that　the

creature　which　made　them　had　a　tail　like　that　of　a　horse；

Cuvier；　seeing　that　the　teeth　and　jaw　of　his　fossil　were　just

like　those　of　an　opossum；　had　the　same　right　to　conclude　that

the　pelvis　would　also　be　like　an　opossum's；　and　so　strong　was

his　conviction　that　this　retrospective　prophecy；　about　an　animal

which　he　had　never　seen　before；　and　which　had　been　dead　and

buried　for　millions　of　years；　would　be　verified；　that　he　went　to

work　upon　the　slab　which　contained　the　pelvis　in　confident

expectation　of　finding　and　laying　bare　the　〃marsupial　bones；〃　to

the　satisfaction　of　some　persons　whom　he　had　invited　to　witness

their　disinterment。　As　he　says：〃Cette　operation　se　fit　en

presence　de　quelques　personnes　a　qui　j'en　avais　annonce　d'avance

le　resultat；　dans　l'intention　de　leur　prouver　par　le　fait　la

justice　de　nos　theories　zoologiques；　puisque　le　vrai　cachet

d'une　theorie　est　sans　contredit　la　faculte　qu'elle　donne　de

prevoir　les　phenomenes。〃　



In　the　〃Ossemens　Fossiles〃　Cuvier　leaves　his　paper　just　as　it

first　appeared　in　the　〃Annales　du　Museum；〃　as　〃a　curious

monument　of　the　force　of　zoological　laws　and　of　the　use　which

may　be　made　of　them。〃



Zoological　laws　truly；　but　not　physiological　laws。　If　one　sees　a

live　dog's　head；　it　is　extremely　probable　that　a　dog's　tail　is

not　far　off；　though