lectures on evolution-第3章

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of　the　present　state　of　nature　may　therefore　be　put　out

of　court。





Fig。　1。Ideal　Section　of　the　Crust　of　the　Earth。



　

We　now　come　to　what　I　will　term　Milton's　hypothesisthe

hypothesis　that　the　present　condition　of　things　has　endured　for

a　comparatively　short　time；　and；　at　the　commencement　of　that

time；　came　into　existence　within　the　course　of　six　days。　I　doubt

not　that　it　may　have　excited　some　surprise　in　your　minds　that　I

should　have　spoken　of　this　as　Milton's　hypothesis；　rather　than

that　I　should　have　chosen　the　terms　which　are　more　customary；

such　as　〃the　doctrine　of　creation；〃　or　〃the　Biblical　doctrine；〃

or　〃the　doctrine　of　Moses；〃　all　of　which　denominations；　as

applied　to　the　hypothesis　to　which　I　have　just　referred；　are

certainly　much　more　familiar　to　you　than　the　title　of　the

Miltonic　hypothesis。　But　I　have　had　what　I　cannot　but　think　are

very　weighty　reasons　for　taking　the　course　which　I　have　pursued。

In　the　first　place；　I　have　discarded　the　title　of　the　〃doctrine

of　creation；〃　because　my　present　business　is　not　with　the

question　why　the　objects　which　constitute　Nature　came　into

existence；　but　when　they　came　into　existence；　and　in　what　order。

This　is　as　strictly　a　historical　question　as　the　question　when

the　Angles　and　the　Jutes　invaded　England；　and　whether　they

preceded　or　followed　the　Romans。　But　the　question　about　creation

is　a　philosophical　problem；　and　one　which　cannot　be　solved；　or

even　approached；　by　the　historical　method。　What　we　want　to　learn

is；　whether　the　facts；　so　far　as　they　are　known；　afford　evidence

that　things　arose　in　the　way　described　by　Milton；　or　whether

they　do　not；　and；　when　that　question　is　settled　it　will　be　time

enough　to　inquire　into　the　causes　of　their　origination。



In　the　second　place；　I　have　not　spoken　of　this　doctrine　as　the

Biblical　doctrine。　It　is　quite　true　that　persons　as　diverse　in

their　general　views　as　Milton　the　Protestant　and　the　celebrated

Jesuit　Father　Suarez；　each　put　upon　the　first　chapter　of　Genesis

the　interpretation　embodied　in　Milton's　poem。　It　is　quite　true

that　this　interpretation　is　that　which　has　been　instilled　into

every　one　of　us　in　our　childhood；　but　I　do　not　for　one　moment

venture　to　say　that　it　can　properly　be　called　the　Biblical

doctrine。　It　is　not　my　business；　and　does　not　lie　within　my

competency；　to　say　what　the　Hebrew　text　does；　and　what　it　does

not　signify；　moreover；　were　I　to　affirm　that　this　is　the

Biblical　doctrine；　I　should　be　met　by　the　authority　of　many

eminent　scholars；　to　say　nothing　of　men　of　science；　who；　at

various　times；　have　absolutely　denied　that　any　such　doctrine　is

to　be　found　in　Genesis。　If　we　are　to　listen　to　many　expositors

of　no　mean　authority；　we　must　believe　that　what　seems　so　clearly

defined　in　Genesisas　if　very　great　pains　had　been　taken　that

there　should　be　no　possibility　of　mistakeis　not　the　meaning　of

the　text　at　all。　The　account　is　divided　into　periods　that　we　may

make　just　as　long　or　as　short　as　convenience　requires。　We　are

also　to　understand　that　it　is　consistent　with　the　original　text

to　believe　that　the　most　complex　plants　and　animals　may　have

been　evolved　by　natural　processes；　lasting　for　millions　of

years；　out　of　structureless　rudiments。　A　person　who　is　not　a

Hebrew　scholar　can　only　stand　aside　and　admire　the　marvellous

flexibility　of　a　language　which　admits　of　such　diverse

interpretations。　But　assuredly；　in　the　face　of　such

contradictions　of　authority　upon　matters　respecting　which　he　is

incompetent　to　form　any　judgment；　he　will　abstain；　as　I　do；　from

giving　any　opinion。



In　the　third　place；　I　have　carefully　abstained　from　speaking　of

this　as　the　Mosaic　doctrine；　because　we　are　now　assured　upon　the

authority　of　the　highest　critics　and　even　of　dignitaries　of　the

Church；　that　there　is　no　evidence　that　Moses　wrote　the　Book　of

Genesis；　or　knew　anything　about　it。　You　will　understand　that　I

give　no　judgmentit　would　be　an　impertinence　upon　my　part　to

volunteer　even　a　suggestionupon　such　a　subject。　But；　that

being　the　state　of　opinion　among　the　scholars　and　the　clergy；　it

is　well　for　the　unlearned　in　Hebrew　lore；　and　for　the　laity；　to

avoid　entangling　themselves　in　such　a　vexed　question。

Happily；　Milton　leaves　us　no　excuse　for　doubting　what　he　means；

and　I　shall　therefore　be　safe　in　speaking　of　the　opinion　in

question　as　the　Miltonic　hypothesis。



Now　we　have　to　test　that　hypothesis。　For　my　part；　I　have　no

prejudice　one　way　or　the　other。　If　there　is　evidence　in　favour

of　this　view；　I　am　burdened　by　no　theoretical　difficulties　in

the　way　of　accepting　it；　but　there　must　be　evidence。

Scientific　men　get　an　awkward　habitno；　I　won't　call　it　that；

for　it　is　a　valuable　habitof　believing　nothing　unless　there　is

evidence　for　it；　and　they　have　a　way　of　looking　upon　belief

which　is　not　based　upon　evidence；　not　only　as　illogical；　but　as

immoral。　We　will；　if　you　please；　test　this　view　by　the

circumstantial　evidence　alone；　for；　from　what　I　have　said；　you

will　understand　that　I　do　not　propose　to　discuss　the　question　of

what　testimonial　evidence　is　to　be　adduced　in　favour　of　it。

If　those　whose　business　it　is　to　judge　are　not　at　one　as　to　the

authenticity　of　the　only　evidence　of　that　kind　which　is　offered；

nor　as　to　the　facts　to　which　it　bears　witness；　the　discussion　of

such　evidence　is　superfluous。



But　I　may　be　permitted　to　regret　this　necessity　of　rejecting　the

testimonial　evidence　the　less；　because　the　examination　of　the

circumstantial　evidence　leads　to　the　conclusion；　not　only　that

it　is　incompetent　to　justify　the　hypothesis；　but　that；　so　far　as

it　goes；　it　is　contrary　to　the　hypothesis。



The　considerations　upon　which　I　base　this　conclusion　are　of　the

simplest　possible　character。　The　Miltonic　hypothesis　contains

assertions　of　a　very　definite　character　relating　to　the

succession　of　living　forms。　It　is　stated　that　plants；　for

example；　made　their　appearance　upon　the　third　day；　and　not

before。　And　you　will　understand　that　what　the　poet　means　by

plants　are　such　plants　as　now　live；　the　ancestors；　in　the

ordinary　way　of　propagation　of　like　by　like；　of　the　trees　and

shrubs　which　flourish　in　the　present　world。　It　must　needs　be　so；

for；　if　they　were　different；　either　the　existing　plants　have

been　the　result　of　a　separate　origination　since　that　described

by　Milton；　of　which　we　have　no　record；　nor　any　ground　for

supposition　that　such　an　occurrence　has　taken　place；　or　else

they　have　arisen　by　a　process　of　evolution　from　the

original　stocks。



In　the　second　place；　it　is　clear　that　there　was　no　animal　life

before　the　fifth　day；　and　that；　on　the　fifth　day；　aquatic

animals　and　birds　appeared。　And　it　is　further　clear　that

terrestrial　living　things；　other　than　birds；　made　their

appearance　upon　the　sixth　day　and　not　before。　Hence；　it　follows

that；　if；　in　the　large　mass　of　circumstantial　evidence　as　to

what　really　has　happened　in　the　past　history　of　the　globe　we

find　indications　of　the　existence　of　terrestrial　animals；　other

than　birds；　at　a　certain　period；　it　is　perfectly　certain　that

all　that　has　taken　place；　since　that　time；　must　be　referred　to

the　sixth　day。



In　the　great　Carboniferous　formation；　whence　America　derives　so

vast　a　proportion　of　her　actual　and　potential　wealth；　in　the

beds　of　coal　which　have　been　formed　from　the　vegetation　of　that

period；　we　find　abundant　evidence　of　the　existence　of

terrestrial　animals。　They　have　been　described；　not　only　by

European　but　by　your　own　naturalists。　There　are　to　be　found

numerous　insects　allied　to　our　cockroaches。　There　are　to　be

found　spiders　and　scorpions　of　large　size；　the　latter　so　similar

to　existing　scorpions　that　it　requires　the　practised　eye　of　the

naturalist　to　distinguish　them。　Inasmuch　as　these　animals　can　be

proved　to　have　been　alive　in　the　Carboniferous　epoch；　it　is

perfectly　clear　that；　if　the　Miltonic　account　is　to　be　accepted；

the　huge　mass　of　rocks　extending　from　the　middle　of　the

Palaeozoic　formations　to　the　uppermost　members　of　the　series；

must　belong　to　the　day　which　is　termed　by　Milton　the　sixth。

But；　further；　it　is　expressly　stated　that　aquatic　animals　took

their　origin　on　the　fifth　day；　and　not　before；　hence；　all

formations　in　which　remains　of　aquatic　animals　can　be　proved　to

exist；　and　which　therefore　testify　that　such　animals　lived　at

the　time　when　these　formations　were　in　course　of　deposition；

must　have　been　deposited　during　or　since　the　period　which　Milton

speaks　of　as　the　fifth　day。　But　there　is　absolutely　no

fossiliferous　formation　in　which　the　remains　of　aquatic　animals

are　absent。　The　oldest　fossils　in　the　Silurian　rocks　are　exuviae

of　marine　animals；　and　if　the　view　which　is　entertained　by

Principal　Dawson　and　Dr。　Carpenter　respecting　the　nature　of　the

Eozoon　be　well…founded；　aquatic　animals　existed　at　a

period　as　far　antecedent　to　the　deposition　of　the　coal　as　the

coal　is　from　us；　inasmuch　as　the　Eozoon　is　met　with　in

those　Laurentian　strata　which　lie　at　the　bottom　of　the　series　of

stratified　rocks。　Hence　it　follows；　plainly　enough；　that　the

whole　series　of　stratified　rocks；　if　they　are　to　be　brought　into

harmony　with　Milton；　must　be　referred　to　the　fifth　and　sixth

days；　and　that　we　cannot　hope　to　find　the　slightest　trace　of　the

products　of　the　earlier　days　in　the　geological　record。　When　we

consider　these　simple　facts；　we　see　how　absolutely　futile　are

the　attempts　that　have　been　made　to　draw　a　parallel　between　the

story　told　by　so　much　of　the　crust　of　the　earth　as　is　known　to

us　and　the　story　which　Milton　tells。　The　whole　series　of

fossiliferous　stratified　rocks　must　be　referred　to　the　last　two

days；　and　neither　the　Carboniferous；　nor　any　other；　formation

can　afford　evidence　of　the　work　of　the　third　day。



Not　only　is　there　this　objection　to　any　attempt　to　establish　a

harmony　between　the　Miltonic　account　and　the　facts　recorded　in

the　fossiliferous　rocks；　but　there　is　a　further　difficulty。

According　to　the　Miltonic　account；　the　order　in　which　animals

should　have　made　their　appearance　in　the　stratified　rocks　would

be　thus：　Fishes；　including　the　great　whales；　and　birds；

after　them；　all　varieties　of　terrestrial　animals　except　birds。

Nothing　could　be　further　from　the　facts　as　we　find　them；　we　know

of　not　the　slightest　evidence　of　the　existence　of　birds　before

the　Jurassic；　or　perhaps　the　Triassic；　formation；

while　terrestrial　animals；　as　we　have　just　seen；　occur　in　the

Carboniferous　rocks。



If　there　were　any　harmony　between　the　Miltonic　account　and　the

circumstantial　evidence；　we　ought　to　have　abundant　evidence　of

the　existence　of　birds　in　the　Carboniferous；　the　Devonian；　and

the　Silurian　rocks。　I　need　hardly　say　that　this　is　not　the　case；

and　that　not　a　trace　of　birds　makes　its　appearance　until　the　far

later　period　which　I　have　mentioned。



And　again；　if　it　be　true　that　all　varieties　of　fishes　and　the

great　whales；　and　the　li