lectures on evolution- 第14部分

to　be　informed；　what　is　the　foundation　for　the　statement　that

evolution　does　require　so　great　a　time？　The　biologist　knows

nothing　whatever　of　the　amount　of　time　which　may　be　required　for

the　process　of　evolution。　It　is　a　matter　of　fact　that　the　equine

forms　which　I　have　described　to　you　occur；　in　the　order　stated；

in　the　Tertiary　formations。　But　I　have　not　the　slightest　means

of　guessing　whether　it　took　a　million　of　years；　or　ten　millions；

or　a　hundred　millions；　or　a　thousand　millions　of　years；　to　give

rise　to　that　series　of　changes。　A　biologist　has　no　means　of

arriving　at　any　conclusion　as　to　the　amount　of　time　which　may　be

needed　for　a　certain　quantity　of　organic　change。　He　takes　his

time　from　the　geologist。　The　geologist；　considering　the　rate　at

which　deposits　are　formed　and　the　rate　at　which　denudation　goes

on　upon　the　surface　of　the　earth；　arrives　at　more　or　less

justifiable　conclusions　as　to　the　time　which　is　required　for　the

deposit　of　a　certain　thickness　of　rocks；　and　if　he　tells　me　that

the　Tertiary　formations　required　500；000；000　years　for　their

deposit；　I　suppose　he　has　good　ground　for　what　he　says；　and　I

take　that　as　a　measure　of　the　duration　of　the　evolution　of　the

horse　from　the　Orohippus　up　to　its　present　condition。

And；　if　he　is　right；　undoubtedly　evolution　is　a　very　slow

process；　and　requires　a　great　deal　of　time。　But　suppose；　now；

that　an　astronomer　or　a　physicistfor　instance；　my　friend　Sir

William　Thomsontells　me　that　my　geological　authority　is　quite

wrong；　and　that　he　has　weighty　evidence　to　show　that　life　could

not　possibly　have　existed　upon　the　surface　of　the　earth

500；000；000　years　ago；　because　the　earth　would　have　then　been

too　hot　to　allow　of　life；　my　reply　is：　〃That　is　not　my　affair；

settle　that　with　the　geologist；　and　when　you　have　come　to　an

agreement　among　yourselves　I　will　adopt　your　conclusion。〃

We　take　our　time　from　the　geologists　and　physicists；　and　it　is

monstrous　that；　having　taken　our　time　from　the　physical

philosopher's　clock；　the　physical　philosopher　should　turn　round

upon　us；　and　say　we　are　too　fast　or　too　slow。　What　we　desire　to

know　is；　is　it　a　fact　that　evolution　took　place？　As　to　the

amount　of　time　which　evolution　may　have　occupied；　we　are　in　the

hands　of　the　physicist　and　the　astronomer；　whose　business　it　is

to　deal　with　those　questions。



I　have　now；　ladies　and　gentlemen；　arrived　at　the　conclusion　of

the　task　which　I　set　before　myself　when　I　undertook　to　deliver

these　lectures。　My　purpose　has　been；　not　to　enable　those　among

you　who　have　paid　no　attention　to　these　subjects　before；　to

leave　this　room　in　a　condition　to　decide　upon　the　validity　or

the　invalidity　of　the　hypothesis　of　evolution；　but　I　have

desired　to　put　before　you　the　principles　upon　which　all

hypotheses　respecting　the　history　of　Nature　must　be　judged；

and　furthermore；　to　make　apparent　the　nature　of　the　evidence　and

the　amount　of　cogency　which　is　to　be　expected　and　may　be

obtained　from　it。　To　this　end；　I　have　not　hesitated　to　regard

you　as　genuine　students　and　persons　desirous　of　knowing　the

truth。　I　have　not　shrunk　from　taking　you　through　long

discussions；　that　I　fear　may　have　sometimes　tried　your　patience；

and　I　have　inflicted　upon　you　details　which　were　indispensable；

but　which　may　well　have　been　wearisome。　But　I　shall　rejoiceI

shall　consider　that　I　have　done　you　the　greatest　service　which

it　was　in　my　power　to　doif　I　have　thus　convinced　you　that　the

great　question　which　we　have　been　discussing　is　not　one　to　be

dealt　with　by　rhetorical　flourishes；　or　by　loose　and　superficial

talk；　but　that　it　requires　the　keen　attention　of　the　trained

intellect　and　the　patience　of　the　accurate　observer。



When　I　commenced　this　series　of　lectures；　I　did　not　think　it

necessary　to　preface　them　with　a　prologue；　such　as　might　be

expected　from　a　stranger　and　a　foreigner；　for　during　my　brief

stay　in　your　country；　I　have　found　it　very　hard　to　believe　that

a　stranger　could　be　possessed　of　so　many　friends；　and　almost

harder　that　a　foreigner　could　express　himself　in　your　language

in　such　a　way　as　to　be；　to　all　appearance；　so　readily

intelligible。　So　far　as　I　can　judge；　that　most　intelligent；　and

perhaps；　I　may　add；　most　singularly　active　and　enterprising

body；　your　press　reporters；　do　not　seem　to　have　been　deterred　by

my　accent　from　giving　the　fullest　account　of　everything　that　I

happen　to　have　said。



But　the　vessel　in　which　I　take　my　departure　to…morrow　morning　is

even　now　ready　to　slip　her　moorings；　I　awake　from　my　delusion

that　I　am　other　than　a　stranger　and　a　foreigner。　I　am　ready　to

go　back　to　my　place　and　country；　but；　before　doing　so；　let　me；

by　way　of　epilogue；　tender　to　you　my　most　hearty　thanks　for　the

kind　and　cordial　reception　which　you　have　accorded　to　me；

and　let　me　thank　you　still　more　for　that　which　is　the　greatest

compliment　which　can　be　afforded　to　any　person　in　my　position

the　continuous　and　undisturbed　attention　which　you　have　bestowed

upon　the　long　argument　which　I　have　had　the　honour　to　lay

before　you。





FOOTNOTES



（1）　The　absence　of　any　keel　on　the　breast…bone　and　some　other

osteological　peculiarities；　observed　by　Professor　Marsh；

however；　suggest　that　Hesperornis　may　be　a　modification

of　a　less　specialised　group　of　birds　than　that　to　which　these

existing　aquatic　birds　belong。



（2）　A　second　specimen；　discovered　in　1877；　and　at　present　in　the

Berlin　museum；　shows　an　excellently　preserved　skull　with　teeth；

and　three　digits；　all　terminated　by　claws；　in　the　fore　limb。

1893。



（3）I　use　the　word　〃type〃　because　it　is　highly　probable　that　many

forms　of　Anchitherium…like　and　Hipparion…like

animals　existed　in　the　Miocene　and　Pliocene　epochs；　just　as　many

species　of　the　horse　tribe　exist　now；　and　it　is　highly

improbable　that　the　particular　species　of　Anchitherium　or

Hipparion；　which　happen　to　have　been　discovered；　should

be　precisely　those　which　have　formed　part　of　the　direct　line　of

the　horse's　pedigree。



（4）　Since　this　lecture　was　delivered；　Professor　Marsh　has

discovered　a　new　genus　of　equine　mammals　（Eohippus）　from

the　lowest　Eocene　deposits　of　the　West；　which　corresponds　very

nearly　to　this　description。American　Journal　of　Science；

November；　1876。











End