the rise and progress of palaeontology-第3章

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fully　Buffon　recognised　the　analogy　of　geological　with

archaeological　inquiries。　〃As　in　civil　history　we　consult　deeds；

seek　for　coins；　or　decipher　antique　inscriptions　in　order　to

determine　the　epochs　of　human　revolutions　and　fix　the　date　of

moral　events；　so；　in　natural　history；　we　must　search　the

archives　of　the　world；　recover　old　monuments　from　the　bowels　of

the　earth；　collect　their　fragmentary　remains；　and　gather　into

one　body　of　evidence　all　the　signs　of　physical　change　which　may

enable　us　to　look　back　upon　the　different　ages　of　nature。　It　is

our　only　means　of　fixing　some　points　in　the　immensity　of　space；

and　of　setting　a　certain　number　of　waymarks　along　the　eternal

path　of　time。〃



Buffon　enumerates　five　classes　of　these　monuments　of　the　past

history　of　the　earth；　and　they　are　all　facts　of　palaeontology。

In　the　first　place；　he　says；　shells　and　other　marine　productions

are　found　all　over　the　surface　and　in　the　interior　of　the　dry

land；　and　all　calcareous　rocks　are　made　up　of　their　remains。

Secondly；　a　great　many　of　these　shells　which　are　found　in　Europe

are　not　now　to　be　met　with　in　the　adjacent　seas；　and；　in　the

slates　and　other　deep…seated　deposits；　there　are　remains　of

fishes　and　of　plants　of　which　no　species　now　exist　in　our

latitudes；　and　which　are　either　extinct；　or　exist　only　in　more

northern　climates。　Thirdly；　in　Siberia　and　in　other　northern

regions　of　Europe　and　of　Asia；　bones　and　teeth　of　elephants；

rhinoceroses；　and　hippopotamuses　occur　in　such　numbers　that

these　animals　must　once　have　lived　and　multiplied　in　those

regions；　although　at　the　present　day　they　are　confined　to

southern　climates。　The　deposits　in　which　these　remains　are　found

are　superficial；　while　those　which　contain　shells　and　other

marine　remains　lie　much　deeper。　Fourthly；　tusks　and　bones　of

elephants　and　hippopotamuses　are　found　not　only　in　the　northern

regions　of　the　old　world；　but　also　in　those　of　the　new　world；

although；　at　present；　neither　elephants　nor　hippopotamuses　occur

in　America。　Fifthly；　in　the　middle　of　the　continents；　in　regions

most　remote　from　the　sea；　we　find　an　infinite　number　of　shells；

of　which　the　most　part　belong　to　animals　of　those　kinds　which

still　exist　in　southern　seas；　but　of　which　many　others　have　no

living　analogues；　so　that　these　species　appear　to　be　lost；

destroyed　by　some　unknown　cause。　It　is　needless　to　inquire　how

far　these　statements　are　strictly　accurate；　they　are

sufficiently　so　to　justify　Buffon's　conclusions　that　the　dry

land　was　once　beneath　the　sea；　that　the　formation　of　the

fossiliferous　rocks　must　have　occupied　a　vastly　greater　lapse　of

time　than　that　traditionally　ascribed　to　the　age　of　the　earth；

that　fossil　remains　indicate　different　climatal　conditions　to

have　obtained　in　former　times；　and　especially　that　the　polar

regions　were　once　warmer；　that　many　species　of　animals　and

plants　have　become　extinct；　and　that　geological　change　has　had

something　to　do　with　geographical　distribution。



But　these　propositions　almost　constitute　the　frame…work　of

palaeontology。　In　order　to　complete　it　but　one　addition　was

needed；　and　that　was　made；　in　the　last　years　of　the　eighteenth

century；　by　William　Smith；　whose　work　comes　so　near　our　own

times　that　many　living　men　may　have　been　personally　acquainted

with　him。　This　modest　land…surveyor；　whose　business　took　him

into　many　parts　of　England；　profited　by　the　peculiarly

favourable　conditions　offered　by　the　arrangement　of　our

secondary　strata　to　make　a　careful　examination　and　comparison　of

their　fossil　contents　at　different　points　of　the　large　area　over

which　they　extend。　The　result　of　his　accurate　and　widely…

extended　observations　was　to　establish　the　important　truth　that

each　stratum　contains　certain　fossils　which　are　peculiar　to　it；

and　that　the　order　in　which　the　strata；　characterised　by　these

fossils；　are　super…imposed　one　upon　the　other　is　always　the

same。　This　most　important　generalisation　was　rapidly　verified

and　extended　to　all　parts　of　the　world　accessible　to　geologists；

and　now　it　rests　upon　such　an　immense　mass　of　observations　as　to

be　one　of　the　best　established　truths　of　natural　science。　To　the

geologist　the　discovery　was　of　infinite　importance　as　it　enabled

him　to　identify　rocks　of　the　same　relative　age；　however　their

continuity　might　be　interrupted　or　their　composition　altered。

But　to　the　biologist　it　had　a　still　deeper　meaning；　for　it

demonstrated　that；　throughout　the　prodigious　duration　of　time

registered　by　the　fossiliferous　rocks；　the　living　population　of

the　earth　had　undergone　continual　changes；　not　merely　by　the

extinction　of　a　certain　number　of　the　species　which　had　at　first

existed；　but　by　the　continual　generation　of　new　species；　and　the

no　less　constant　extinction　of　old　ones。　



Thus　the　broad　outlines　of　palaeontology；　in　so　far　as　it　is　the

common　property　of　both　the　geologist　and　the　biologist；　were

marked　out　at　the　close　of　the　last　century。　In　tracing　its

subsequent　progress　I　must　confine　myself　to　the　province　of

biology；　and；　indeed；　to　the　influence　of　palaeontology　upon

zoological　morphology。　And　I　accept　this　limitation　the　more

willingly　as　the　no　less　important　topic　of　the　bearing　of

geology　and　of　palaeontology　upon　distribution　has　been

luminously　treated　in　the　address　of　the　President　of　the

Geographical　Section。



The　succession　of　the　species　of　animals　and　plants　in　time

being　established；　the　first　question　which　the　zoologist　or　the

botanist　had　to　ask　himself　was；　What　is　the　relation　of　these

successive　species　one　to　another？　And　it　is　a　curious

circumstance　that　the　most　important　event　in　the　history　of

palaeontology　which　immediately　succeeded　William　Smith's

generalisation　was　a　discovery　which；　could　it　have　been　rightly

appreciated　at　the　time；　would　have　gone　far　towards　suggesting

the　answer；　which　was　in　fact　delayed　for　more　than　half　a

century。　I　refer　to　Cuvier's　investigation　of　the　mammalian

fossils　yielded　by　the　quarries　in　the　older　tertiary　rocks　of

Montmartre；　among　the　chief　results　of　which　was　the　bringing　to

light　of　two　genera　of　extinct　hoofed　quadrupeds；　the

Anoplotherium　and　the　Palaeotherium。　The　rich

materials　at　Cuvier's　disposition　enabled　him　to　obtain　a　full

knowledge　of　the　osteology　and　of　the　dentition　of　these　two

forms；　and　consequently　to　compare　their　structure　critically

with　that　of　existing　hoofed　animals。　The　effect　of　this

comparison　was　to　prove　that　the　Anoplotherium；　though　it

presented　many　points　of　resemblance　with　the　pigs　on　the　one

hand　and　with　the　ruminants　on　the　other；　differed　from　both　to

such　an　extent　that　it　could　find　a　place　in　neither　group。

In　fact；　it　held；　in　some　respects；　an　intermediate　position；

tending　to　bridge　over　the　interval　between　these　two　groups；

which　in　the　existing　fauna　are　so　distinct。　In　the　same　way；

the　Palaeotherium　tended　to　connect　forms　so　different　as

the　tapir；　the　rhinoceros；　and　the　horse。　Subsequent

investigations　have　brought　to　light　a　variety　of　facts　of　the

same　order；　the　most　curious　and　striking　of　which　are　those

which　prove　the　existence；　in　the　mesozoic　epoch；　of　a　series　of

forms　intermediate　between　birds　and　reptilestwo　classes　of

vertebrate　animals　which　at　present　appear　to　be　more　widely

separated　than　any　others。　Yet　the　interval　between　them　is

completely　filled；　in　the　mesozoic　fauna；　by　birds　which　have

reptilian　characters；　on　the　one　side；　and　reptiles　which　have

ornithic　characters；　on　the　other。　So　again；　while　the　group　of

fishes；　termed　ganoids；　is；　at　the　present　time；　so　distinct

from　that　of　the　dipnoi；　or　mudfishes；　that　they　have　been

reckoned　as　distinct　orders；　the　Devonian　strata　present　us　with

forms　of　which　it　is　impossible　to　say　with　certainty　whether

they　are　dipnoi　or　whether　they　are　ganoids。　



Agassiz's　long　and　elaborate　researches　upon　fossil　fishes；

published　b