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Canadian  Institute  for  Historical  Microreproductions  /  Instltut  canadien  de  microreproductions  historiques 


4 
I 


Technical  and  Bibliographic  Notes  /  Notes  techniques  ei  I:>'b:iOQraphiques 


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1  2  3 


1 

2 

A 

5 

L'axemplaire  filmA  fut  rsproduit  grace  ^  la 
gAn^rositA  de: 

University  of  British  Columbia  Library 
Vancouver 


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conformity  avec  les  conditions  du  contrat  de 
filmag*. 

Lea  examplairea  onglnaux  dont  la  couverture  en 
papiar  att  imprim^e  sont  filmAs  en  commencant 
par  la  premier  plat  at  en  terminant  soit  par  la 
dernlAre  page  qui  comporte  une  empreinte 
d'impratsion  ou  d'illustration.  soit  par  le  second 
plat,  selon  le  cas.  Tous  les  autres  exemplaires 
origir>aux  sont  film^s  en  commenpant  par  la 
premiAre  page  qui  comporte  une  empreinte 
d'impression  ou  d'illustration  et  en  terminant  par 
la  darniAre  page  qui  comporte  une  telle 
empreinte. 

Un  des  symboles  suivants  aoparaitra  sur  la 
derniAre  image  de  cheque  microfiche,  selon  le 
cas:  le  symbole  '—^-  signifie   "A  SUIVRE   .  le 
symbole  V  signifie  "FIN  ". 

Les  cartes,  planches,  tableaux,  etc..  peuvent  etre 
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Lorsque  le  document  est  trop  grand  pour  etre 
reproduit  en  un  saul  cliche,  il  est  film^  d  partir 
de  Tangle  supArieur  gauche,  de  gauche  ^  droite. 
et  de  haut  en  bas.  en  prenant  le  nombre 
d'imagas  nAcessaire.  Les  diagrammes  suivants 
iliustrent  la  mAthode. 


2  3 

5  6 


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ORIGIN    OF    SPECIES 

BY  MEANS  OF  NATURAL  ShLLCTlON 


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1 

ON  TUE  ORIGIN  OF  SPECIES 


5 


INTRODUCTION 


H'hen  on  board  n.. M.S.    Hengle,  as    naturalist.  I 
uch  struck   with  certain  fa.-Ls  in  the  distril 


in 


wan 


.,      ■    -    ..  ,"  — •••■ '  lo  111   Luu  uisirutution  of 

he  „.    ,l„u„u.s  ot  South  An.erica,  an.l  in  the  ^^eolo^ica 
elafnns  of  the  p-esent  to  the  past  inhabitants  ofTha 
cont.nent      I  hese  facts  seemed*  to  me  to  throw  some 
111,'ht  on  the  orifTui  of  species-that  mystery  of  mysteries 
as  it^    ■  T''  ""i^'^  ^^  """^  *'^""'"  ^"-eatest  philosophers' 
Oil  my  return  home,  it  occurred  to  ,ne,  in  Wir,  thai 
.omethniK  might  perhaps  be  made  out  on  this  c.u^s   on 
by  patiently  accumulating  and  reflecting  on  all  so^ 
of  tactewh.cb  could  possibly  have  any  l>earin^  on  U 
After  hve  years' work  1  allowe.l  myself  to  speculate  on 
the  subject,  and   drew  up  some  ^hort  notL  ;  these  I 

Hiiich  then  seemed  to  me  pndmble  :  from  that  perir>d 
to  the  present  day  1  have  steadily  pursued  the^Jml 
object,  i  hope  that  I  may  be  excused  for  er.terin^on 
these  personal  details,  as  I  ^ve  them  to  show  that  I 
bene  not  been  ha,sty  m  coming  to  a  decisi„„ 

,r.:    L'^r  .k"  ""'"  "*'"^>'  ^"'***'*'*^  '   '"'t  as  it  will  take 

r.    two  or  three  mure  years  to  omplete  it,  and  a.  n.y 

althis  far  from  strong,  I  have  been  ur,.ed  to  publish 

to  do  this,  as  Mr.  Wallace,  who  i«  pow  of.-i..:...,  ^t 
natural  h.story  of  the  Malay  archipelago,  b'a/ "arrived 
at  almost  exactly  the  same  jreneral  concl 


have  on  the 


exac 
urig-iu 


of 


usions  that  I 


■i{»ecie«.     l^uot  year  he  sent 


B 


me  a 


2  ON  THE   ORIGIN   OV   SPECIblS 

memoir  ou  i\u>  sui.|t;(t,  with  a  reijuost  that  I  woalii 
hirward  it  to  >ir  Charles  Lyell,  wlio  sent  it  to  the 
!,iiiift'-iii  ^0(•iety,  and  it  is  '  pnt.li>hed  in  tlie  third 
Toliiino  of  the  JourTial  of  tliat  Soonity.  .^ir  ('.  I.yeil 
iiid  Dr.  HoolxtT,  who  hoth  knew  of  my  work  -tlu! 
hittor  havin;r  r«'a<l  my  sketch  ot  i;!U  hotioured  me 
by  thinkiii:r  it  Hiivi8;Ude  to  piihlihii.  with  Mr.  W'alhice''* 
••xct'ilt'dt  memoir,  .some  li.-ie  .'xtraots  from  rny  niaiiu- 
-crijits. 

Iliis    Alvstraet,   whieh    I     now   |)iil)li>h,  must   neces- 
sarily he  imperu-ot.      I  cannot  here  pve  reference<  and 
authorities    for    my   several    statements  ;  ami    1    inust 
trust    to    the  re^nier  reposing   some  coiitiiUMice  in   my 
accuracy.     No  douht  errors  will  have  crept  in,  though 
1  hope  i  have  always  heen  cautious  in  trusting  to  troctd 
authorities  aiv)ne.      1  win    here  ^ive   only  the  fjeneral 
conclusions  at  which  1  have  arrived,  with  a  few  facts  in 
illustration,  hut  which,  1  hope,  in  inostcaaes  will  suffice. 
No  one  can  feel  more  sensible  than  I  do  of  the  nece.s.sitv 
of  hereafter  publishing   in  detail    all    the   fact«,  with 
references,  on  which  my  conclusions  have  been  frrounded ; 
.ind  I  hope  in  a  future  work  to  do  this.     For  1  am  well 
aware  that  sc^ircely  a  single  point  is  discussed  in  this 
volume    on    which    facts     cainiot    be    adduced,    often 
apparently  leading?  to  conclusions  directly  opposite  to 
those  at  which   I  have  arrived.     A  fair  result  can  be 
obtained  only  by  fully  stating  and  balancing;  the  facts 
and   arffumeiita  on  both  sides  of  each  question  ;  and 
this  cannot  pofisihly  l)e  here  done. 

I  much  ref,^ret  that  want  of  space  nreventj^  myhavint^ 
the  satisfaction  of  acknowledfrinjr  the  ^a'nerous  assist- 
ance which  I  have  received  from  very  many  naturalists, 
eome  of  them  personally  unknown  to  me.  1  cannot, 
however,  let  this  opportunity  pass  without  expressiiiji 
my  deep  obligations  to  Dr.  Hooker,  who  for  the  last 
fifteen  years  has  aided  me  in  every  possible  way  l»y  his 
lartre  stores  of  know led^re  and  his  excellent  judtrment. 

In  couMderui:;  the  « >rii.nn  of  .>jtrcies,  it  is  quiie  c»»ii- 
ceivablo  that  a  naturalist,  retlectini;  on  the  iiuitual 
affinities   of  or^^anic   beings,    on    their    embryoloirical 


INTRODUCTION  3 

relatiou^.  their  peotrrapbica!  distril.ntion,  jrfv.i.uMcal 
*uccesH,on,  a,.d  other  .uch  tacts,  ini^ht  cora.  t  jfi 
cone  usum  that  ea..h  spene.  ha.l  not  h.^en  ind'  ,..„!,  /" 
T^ah.d,  hut  had  descended,  hke  va.i,.tio.,  from  othJr 
^peccH  Nevertheless,  such  a  conclusion,  even  if  lu 
•.'Hided,.ould  he  UM..atiHfactorv,  until  it  cJuld  1^  shoin 
hou'the  mnumorablo  npecies  in'hal.uin,MhiH  Jorld  We 

H  ructiire,  for  u-stance,  of  the  woo.ipecker,  «ith  its  feet 
ta.I,  hoak,and   ton,n,e,  so  adn.irai,  v  adar  te  1    to  c  ,  1' 

trees,  whch  has  seeds  that  must  he  transnorted  hv 
certauj  nrds,  and  whi.-h  has  /!o«-ers  with  se  S  e^^^^ 
ahsolutely  re<|u.rin..  the  agency  of  cer  Jn  [l^cN  to 
tTH.i.  pollen  from  one  flower  to  the  other 't  email? 
l.reposterous  to  account  for  the  structure  of  thinaS 
Ih    et'^of  :"?  ''  several  distinct  organic  Kn^t^' 

Hie   author   of  the    I't-^tiye^   of    Creation    nould     I 

^-i£d\ir.-^;-:----^^ 

£.;«"';'"'  ""'"?  I?  '"^  ^«  '-   "«  explanation     o^ 
eaves  the  case  o    the  coadaptations  of  or-ani.  hein.  s 
to  each  other  and  to  their  physical   conditio      of      e 
intouched  and  unexplained      '  "«'"'^''--  ot  lite, 

cleiV'i'  ^'.'T^'"''«'  "^,  t''e  hi^rhest  im,,ortan.e  to  train  a 

t^.!z^''  .'['^?  ^'-  —  of  midihcarion ;.::;;'",:: 

""' ''■'■■      ■■' '  '''0  Collin 


It  seemed  to  xw 
ticuted  n 


f  I»roha!.le  that 


tement  of  my  ohserv.-.ti 


nmials  an 


:i  careful  studvof  d 


ons 


il  of  cultivated  plants  would  offe 


onie;- 


rthe 


4  ON  THE   ORIGIN    OK  SPECIES 

best  chaiue  ot  ir.akir.ff  out  this  o1w(  urfi  prohlem.  Nor 
have  1  been  dirvippoiiiUHl  ;  in  this  and  in  all  other 
ncrplexint?  cases  I  have  iuvariahly  fcund  that  our 
aowle.lsfe,  imperfect  ihoutfh  it  be,  of  variation  under 
tlonipsti.-ati<.n,  atforded  the  best  and  safest  due.  I  may 
venture  to  expre-s  mv  conviction  of  the  hit'h  value  of 
such  studies,  altlioutrh  they  have  been  very  commonly 
neglected  bv  naturalists.  ,       ^    » 

From   the^e  considerations,  I  shall   devote  the  hrst 
chapter  of  tliis  Al»stract  to  Variation  under  Domestica- 
tion.     ^^■e    shall     thus    see    that    a   lartre   amount  of 
heredit-irv  moditication  is  at  least  po>Mlde  ;  and,  what 
IS  e(iuallv  or  more  imjiorUnt,  we  shuU  see  how  y-reat  la 
111.'   power  of  man  in  accumulatinir    l>y  his  Selection 
successive  slight  variations.      1  will  then  pa.ss  on  to  the 
variability  of  species  in  a  state  of  nature  ;  i>ut  I  shall, 
unf<.rt.inatelv,  \>e  comi>eiled  to  treat  this  subject  far  too 
hrietly,  as  it  can   be  treated  properly  only  by  ^iviii^ 
Ion-  cat;iloirue.s  of  lacUs.      Wo  shall,  however,  be  en- 
abled to  discuss  what  circumstances  are  most  favourable 
to  variation.      In   Uie  next  chapter  the    Strutf^le    for 
Kvisten.e  amontrst  all  or^nic  Injin^  throutrhout  tlie 
world,    which   inevitably   foUows  fn.m   the   hitfh    a^eo- 
rnetrical   ratio    of  their  increase,   will   be    treated    ot. 
rhis  is  the  doctrine  of  Maltbiis,  applied  to  the  whole 
animal    and    vciretahle    kinirdoms.       As    many    more 
individual^    f  each  species  are  horn  than  c^n  possibly 
survive;  and  as,  conse.juently,  there  is  a  trequenUy 
recurring  struntfle   for  existence,  it  follows  that  any 
beintr,  if  it  varv  however  sliy-litly  in  any  manner  proht- 
•itde  to  itself,  under  the  c«)inpiex  and  sometime.^  varying 
conditions  of  life,  will  have  a  better  chance  of  surviving, 
and     thus    he    uaturaily    mected.      From    the   fro"^ 
principle  of  inheriUnce,  any  selected  variety  will  tend 
to  propatrate  its  new  and  modified  form. 

•rhis  fundamental  subject  of  Natural   Selection  wiU 
be  treated  at  some  length  in  the  fourth  chapter  ;  and 

we   shaii    Lheii    see  now    >ai!ir.vi   .-eie- <.:'•"  ^-^ -  ■-» 

evitablv  causes  much   Extinction  of  the  less  improved 
forms  of  life,  and  leads  to  wliat  I  have  called  Divergence 


INTRODUCTION  I 

of  (l.aracter.  In  the  next  chapter  1  shall  discuw,  the 
cornpU.  and  Ilt.lo  k,wn  laJs  of  vanatio,ra"l  of 
orrelat.nnoftrnnvth.  In  the  four  H^MMM-iirie  chapt^,^ 
the  most  apparent  ar.d  cravest  diHicilties  on  the  tlieonJ 
w.U  he^ne.i  :  nan.oly,  first,  the  diffi<uitie.s  of  trans? 
tjons   or  in   undersLandinir  how  a  simple   hein-  or  a 

h.*fhl>    devoloned    bein^    or   olahorately    construrted 
orpan  ;  .ec,nul^y,  the  suhjert  of  ln>tin.-t,or  U  e  mentol 
powers    of  animal,;    thinily,   HyhridiH'n,,   o     tbe^ 
fertility  of  species  and    the  fertility  of  varieties  wh^n 
mterorossed  ;    and   fourthly,   thfe   imperfe<>tfon  of  the 
.e*do*r.caI  Record.     In  the  next  chapter  1  « hall  consider 
tho<reolo4.ncal  succession  of  orfranic  liein^rs  thruuphout 
.mo;  ,„  the  eleventh  and  cwelfth,  their%e< JaS 
d.stnbut,on  throui^hout  npace  ;  in  the  thir'eerfth    th^ 
.lassifica  lonor  mutual  affinities,  botii  when  mature  and 
in  an  emhryonic  condition.      In  the  L-ust  chapter  I  61^11 
.nve  a  bnef  reca{,,tulation  of  the  whole  work ,  and  a  ^w 
coiioludiniT  remarks. 

No  one  outfht  to  feel  suqjrise  at  much  remaininir  a. 
yet  unexplained  m  re^rard  to  the  oritrin  of  specie*,  an^ 
vanet.e.s,  if  he  make«  due  allowance^^orou /profound 
urnorance  m  re.^ard  to  the  mutual   relations  of^rtSe 

::,;  :f,^';r  '^:^-^  --'^-b-  and  is  very  numerous,  and 
»,^  an,.  u_ral!,ed  species  ha.,  a  narrow  ran^e  and  i« 
f  r    n  1      f'  '•l^latmns  are  of  the  highest  in.porUnce, 

t>.lKne,  the  future  sMcce.sa  and  modiHcation  of  everr 
H.halMUnt  of  thi.  «orld.  .Still  less  do  we  know  of  the 
mutual  relatione  of  the  innumerable  inhalutantT  of  the 
-on.  duni,<r  the  many  p..st  ce.dopcal  epochs  in  it^ 
^''.^tury.  Althou-h  much  ren.ains  obscure,  and  wiU 
\ou,r  remain  obscure,  I  can  entertain  no  dou  lafte 
I"  rnos  delil,erate  study  and  dispas.sionata  jud^onenl 
"f    ^hu'h    I    am    capable,  tliat   the    vi...    ^.yLu^^    l 

^-'l^wTr^^^l:^'"^  "^'''^  '  ^^'■'"^'•Jj'  ^"t.rtj;;6d 

.reat^l     /.  ^'"""^  '^^""T    ^'^^    ^^^'^  indej.endentlr 

<rtated-i8   erroneous.       1    am    fully   conviiced    that 


6  ON  THK    ORIGIN    OF   SI»FX'IES 

species  are  not  immutable  ;  hut  t)iat  those  heloii^ing  to 
what  are  called  tlie  same  genera  are  liiiejil  descendanta 
of  some  (ilher  and  jfenerally  extinct  speries,  in  the  same 
manner  a>  the  acknowledfred  varietie-  of  any  one  specie* 
are  the  descendants  of  that  species.  Furthei  more,  1 
am  coiivinoed  that  Natural  Selection  li.'k;  hecn  the  mail) 
hut  not  exduHive  means  of  modific<ition. 


CHAPTKU I 

VARIATION     I  NDKH    DOMKSTKATKO 

t  .  Mans  power  of  MX-ti!!^,''''''^"'*''''*''  '"vourmhl, 

\ri,KN  we  l(K,k  to  the  iii.lividuals  of  the  same  VHrietv 
or    sub-variety   of    our    older   cultivated     nknts  TnX 
amma  s,  one  of  the  rtrst  point,  whidi   strike     us    i 
'e  inriJ'T'^j^'  '''''  ">' ^«  ^-^  -'^h  other  tl^n  io 

nature      Wh'i  "'^  ""VP*^^'^'^  "''  ^'^'-'^^y  ">  «  «tate 
.1  nature.     \\  hen  we  reflect  on  the  vast  diversitv  of 

the  plants  and   animals  which   have  been  c'h  v^ed 

iffer;n"cIi*;n':tV""S'/"""*^  ^"  ^^^  under  the  mo^ 
J.tterent  climates  and  treatment,  ]  think  we  are  driven 

t"  conclude  that  this  preat  variability  is  simp™  due  to 

d-MonToPlif^n'ot'"''"";  '""''"'^  ^«^" --'^  ->'«"o" 
tZ    Sil\       T-  "J"^?'^  ^'  *"'^  somewhat ditferent 
"om,  those  to  which   the   parent- species    have    W, 

'"   ^^-";-wiis  or  iijt!   lo  cause  anv  aonreriafil* 

Hn.ount  of  variation  ;  and  that  when  the  orSSion 
l.as  once  begun  to  vary,  it  generally  conUouS^  toJi; 

7 


•w...^ 


■  i'A^M''^6: 


8 


ON  THE   ORIGIN    OF   8PK(  1F*S 


for  many  ^(Mieralionrt.     No  cnne  i*  on   rt'cnnl  of  a  van- 
al.le  bei'ntr  ceasii.t;  to  be   varml.le   mi^lor   .Miltivation. 
Our  oldo,st  cultivated   plants,  such  as  wheat,  sUll  often 
yii'ld   new  varieties:    our  oldest  dnme-^licated   .imruaU 
are  still  ca^Kihle  of  raj.id  improvement  or  mo.lih.ation. 
it  has  been  dispuU'd  at  what  peri..-  •;:  lite  the  oauso. 
.,1   vanal.ilitv,  whatever  thev   may   be,  generally  aet  ; 
whether  durintr  the  carlv  or  late  period  of  development 
of  the  embryo,  or  at  the  instant  of  conception,   (ieotfroj 
St  11  ilaire'-'experimenU  show  that  unnatural  treatment 
of  the  embryo  causes  monstrosities;  and  monstrosities 
cannot   1«  separated   by  any  clear  line  of  distinction 
from  mere  variations,      liut  I  am  strongly  inclined  to 
■usj)ect  that  the  most  frequent  cause  of  variability  may 
be   attributed    to   the    male    and    female    reproductive 
elements  haviiiif  been  affected  prior  to  the  act  of  con- 
ception.     Several  reajsons  make  me  believe  in  this  ;  but 
the  chief  one  is  tlie  remarkable  effect  which  confine- 
ment or  cultivati..n  has  on  the  function  of  the  repro- 
ductive system  ;  this  system  appearinjr  to  be  far  more 
susceptible  than  any  other    part  of  tlie  ortranisatiou, 
to  the  action  of  any  ciiatisre  in  the  conditions  of  lite. 
Nothint:  is  more  easy  than  to  tame  an  animai,  and  few 
thmtrs  more  ditiicult  than  to  jret  it  to  breed  freely  under 
conrtnement,  <:ven  in  the  many  cases  when  the  male  and 
female  unite.      How  many  animals  there  are  which  will 
not  breed,  thonuh  livinir  loiifr  under  not  very  clo>e  .-(.n- 
tiuement  in  their  native  country!      llus  is  ecneraliy 
attributed  to  vitiated  instincts  ;  but  how  many  cultivated 
plants  display  the  utmost  vitjoisr,  and  yet  rarely  or  never 
seed  !      In  s.nne  few  such  cases  it  has  been  discovered 
that  very  trilling  chan^'es,  such  as  a  little  more  or  less 
water  at  some  particular  j.eriod  of  trrowth,  will  .letermiiie 
whether  or  not  the  plant  sets  a  seed.      I   cannot  here 
enter  on  the  copious  det.iils  which   1  have  collected  on 
tliis  curious  subject ;  but  U>  show  how  sintrular  the  laws 
are  which  determine  the  reproduction  of  animals  under 

coiihneineiu,    i     may    ju^-t    nivniiuii     tn^i.    .a,,,.--> » 

animals,  even  from  the  tropics,  b-eed  in  this  country 
pretty  freely  under  continement,  with  the  exception  of 


VARIATION  1;NT)KR  DOMESTICATION        9 

the  plantitrrades  or  bear  family;  w  l„>rea.s  can.ivo.o.,, 
t'inis  with  the  rarest  exceptions,  hanllvever  lav  f.-rtile 
eniTH.    Many  exotic  i,hiubi  have  pollen  utterly  H(;rthU.«s 

m  the  same  exact  coiMitioiia.s  in  the  most  sterile  hvhridx' 

\\  hen,  on  the  one  han.l,  wo  .ee  dr.mestiratf.l  animals 

ajul  plaiit^,  th<Mu:h  otlen  weak  and  >icklv,  yet  hreedinir 

Viite  treely  un.ier  continement ;  and  wht-'n,  on  the  other 

hand,  we  see  individuals,  thoiith   taken  vountr  from  a 

/  f     r    ''•''!'"-«'Jf  f'-^-'Jy  tamed,  lon>f-lived.  an.i  healthy 

(Of  which  I  could  ^ive  numerous  iiiKtmces),  v,.t  havinir 

their  reproductive  system  so  serioualv  affected   hv  un- 

perceived  causes  as  to  fail  in  actintf,'  we  need   not  }>e 

HurpriHed  at  this  system,  when  it  does  act  under  con- 

hnemeut,actuiff  not  quite  retfularly,  and  producnijf  otf- 

spring  not  nerfectly  like  their  parents. 

Merihty  has  been  said  to  Iks  the  bane  of  horticulture  • 
l>ut  on  this  view  we  owe  variability  to  the  same  cause 
which  produces  sterility;  and  variability  is  the  source 
ot  all  the  choicest  productions  of  the  garden.  1  may 
•ifl'l,  that  as  some  ory-anisms  will  breed  freely  under 
tbc  most  unnatural  conditions  (for  instance,  the  rabbit 
and  ferret  kept  in  hutches),  showintr  that  their  repro- 
'luctive  system  has  not  been  thus  affected  ;  so  will  some 
animals  and  plants  withstand  domesti.-ati..n  or  cultjva- 
Uon,  am.  vary  very  sli^htly-perii.ips  hardly  ,nore  ''..in 
m  a  >tale  of  nature. 

A  ionjr  list  could  easily  be  civen  <.f '  sportin^r  plantj^ '  • 
'.V   this  term  frardeners  mean  a  sintrh-   bud   >  r  offset* 
wtnch  su.l.lenly  assumes    a  new  and    sometimes  ver^ 
Afferent  character  from   that  of  the  rest  of  the  plant 
-uch    buds  nan    be  propairated    by  i^raflinir,  etc.,  and 
sometimes    by    seed.       Tbe^e    'sports'    are   evtremeU 
rare  under  nature,  but  far  from  rare  under  cultivation  ■ 
and  in  this  case  we  see  that  the  treatment  of  the  parent 
fias  affected  a  bud  or  offset,  and  not  tlie  ovules  or  pollen, 
't '8  t';e  "pi'ium  of  most  physiol<»iri,t«  that  there  is  no 
essential  difference  between  a  bud  and  an  ovule  in  their 


-Ui^-Ca     O 


support  my  view,  that  variabilit 


i   loriualion  ;  so  that,  in   fact,  '  sj.orta 


buted  to  the  ovul 


y  may  !)e  lartfely  attri- 


es  or  pollefi,  or  to  both,  havinjf  [ 


een 


^^■rTrPS 


7mi9Si' 


;3>W-;«S*«^^;^  "MSmX^Q^Si^^ 


10 


ON   THK   ORKilN    OK   SPKCIKS 


affected  )iv  the  treatment  of  the  parent  [nior  to  the  act 
of  (•t)nce|iti(»ri.  These  iTise>^  anyli'tw  show  that  variation 
is  not  iieifysarily  conneeted,  as  some  authors  have  9U|>- 
|t(»s(Ml,  with  l)ie  act  ot  ^'cnerat ion. 

Sceillintrs  from   tlio  same  fruit,  and  tlio  youn^  of  the 
Kirne  litter,   sometime^   differ  ronsideraldy   from   eat-h 
«)thfr,  thoiiirli  hoth  the  yoniiir  and  the  parents,  as  MuUcr 
lia-^  rt'inarktMl,  liave  apiiareiitiy  ht-en  ev posed  to  exaetly 
the  sjiine  ronditions  of  life  ;  and  tlii«  shows   l„)w  iiiiim- 
tii.rt.int  the  direct  effect-  of  the  coniliti(»ns  of  life  are 
•ill  cuiipanson  witli  the  laws  of  reproduction,  of  irrowth, 
and  of  inheritance  ;  for  had  tlie  action  of  the  conditions 
hecn  direct,  if  any  of  the  youiiL'^   ha<l  varied,  all  would 
proliahlv  have  varied  in  tliesaine  inaimer.   To  jiidire  how 
mu.  h,  in  tlic  case  of  any  variation,  we  siiouhl  attiili;:te 
to  the  direct  action  of  heat,  moisture,  li^^lit,  food.  etc. , 
is  most  ditlicult  :   my  impres-ion  is,  tliat  with  animals 
such  agencies  have  jiroduced   very  little  direct  eth'ct. 
thmi^'h  apparently  mine  in   the  ivise  t)f  plants.      I  nder 
this  point  of  view',  -Mr.  liuckman's   recent  experiment- 
on  plants  are  extremely  valuable,      ^\■lu•n  all  or  nearly 
all    the  individuals  exposed    to  certain   conditions   are 
affecteil  in  the  same  way,  the  chaiiire  at  first  appears  to 
he  directlv  due  to  sucli  condition?  ;  Imt  in  some  oa.ses  it 
can   l>e   sliown   that  quite  opposite  conditions   produce 
similar  chaiifres  of  structure.      Nevertheless  some  slijfht 
amount  of  dian  -'    may,  I  think,  l)e  altrihuted  to  the 
direct  action  of  the  conditions  of  life— as,  in  some  cases, 
increased  size  from  amount  of  food,  colour  from  par- 
ticular  kinds  of  food  or  from  litfht,  and   perhaps  the 
thickness  of  fur  from  climate. 

Hahit  also  has  a  decided  influence,  as  in  the  period 
of  lloweriiii^  with  plants  when  transported  from  one 
climate  to  another.  In  animals  it  has  a  more  marked 
effect  ;  for  instance,  I  find  in  the  <lomestic  duck  that  the 
hones  of  llie  win?  wei;rh  le.ss  and  the  hones  of  the  let; 
more,  in  jtroportion  to  the  whole  skeleton,  than  do  the 

)u;;cs  Hi  i;ic:  •.-.  uti  •..!:">  n.  ,    n-.-.-^    i    j-i'  -•■ '••■• 

change  mav  he  safely  attrihuted  to  the  domestic  duck 
flyiuff  mucli  less,  and  walking  mure,  thau  it«  wild  parent. 


i'S^^'^tM;-*' 


v^^i: 


VARIATION  ITNDKR  DOMRSTICATIOV      n 

TTie^roat  and  .nherited  devolopment  of  th,.  ,.,{  l.-rs  in 
m.lk...l,  ,„   co,„,,aris.„.  with    ti.e  s,at,.  of  tin'  e    ™^ 

"Ml.       .Not  a    sMiL^Ie  d.)mr>f;r   animal    can    bo    named 
^In.h   l.as   not   in   Home  rountrv  droopin  .  .L     Zd 

:!"••  to  tlu.  .i,M,so  of  the  m...,I..s  r,f  th..  ...  ir    from  the 
animals   not    he  n-'    much    il  .n,,...!    i        j 

n  ,.n  ;       "*''.''"  y^''*-".-""!  «H1  he  hereafter  hriefly 

n.entuned  I  w,l)  here  only  allude  to  v,hat  n.av  e 
•■■'lledeorreK.t,onoft,ro«-th.  Any -han^^e  in  ,  e  e  t  o 
'.r   larva   «,11   almost   eertainlv  'entail    eha,,!'.  ,2 

jnah,rea,nM.al       Inmons,ro.ties.theeorr;iiio         : 
"eon  .ju.te  .l,stnu-t  parts  are  verv  eurious  :  an.l   mar.v 

n.stnneesarotf.veninlsi.loreinM.rfrovM.  IliVnr  '.T^^^ 
'vork  on  th.H  suhje.-t.      Mreeders  helieve  tl         .  .;  hi: 
are  ahnost  always  accompanied    by  an  eIon.^.t;d   lu' 
crV'lf '■',";""  of  correlation  are  .[uite  whin^iea   :   tbt 
cat^  «,th    blue  eyes  are   iuvariahlv  deaf;   colour  and 
oust,  ufonal  pecul.anties  ,.o  to.^eiher,  of  w  lie     rna 
emarkab  e  eases  could   1^  ,Mven  amon^^st  a,    m  Is  a  . 
plants       Prom  the  facts  collected   hy  lleusin-r.-p    /"' 
prs  that  whke  sheep  and  pi^..  are  ditrerentU  atfecUd 
n)m  coloured    ndi^idual8  by  cert;iin  ve.^et.    1^  ,t   so   h 
Hairless  do^,  have  imperfect  teeth  ;    Ic.ni,;-  ai  ^     Zd 
coarse-ha.red  anin.aLs  are  a,.t  to  have,  a.  is  asscr  ed   lout 
or  many  horns;  pi.^eor.s  w'.th   feath;red   f'et  W^  S 
between    he.r  outer  t<,.s  ;  pi,.c.,ns  »ith  short  h^i'ks  ha  e 
mall  feet,  and  those  with  lon^  beaks  lar.^e  feet      I  e nee 

"   hrr%r  "■l;"'";^'  ^"'   ^^"«  -^mentln^an; 

Afii      ®    '^'"'^    ^^'"""^^    certainly    unco'i^cn.n.i;- 

'   'dify  other    parts  of  the    structure,    owi,?^    t^   u^^ 

-..-tenous  laws  of  the  correlation  of  ^'owth.*^ 

J ''«/esult  of  the  various,  quite  unknow,.    or  .V,^l.. 

^Tersilu^r  t  -'"""n'"  '^  '"''"it^-ly  complex'aud 
in.rsn,ed  it  is  well  worth  while  carefuUv  to  studv 
ti^e   several    treatises    publishe<l    ou    some   i'f  If  "Id 


12 


ON   TlIK   OKH.IN    OF  srKC:iF> 


«-iiltivatt«<l  {>I:iiit.-.  .1-  on  tli*'  hyacinth,  jioUito,  pvfti  th« 
(lahl'.i,  ••;'  .  iiwl  it  1-  r»'j»lly  Hurprisiiiir  to  note  th»* 
rndU'^^N  (("lilts  in  stractiin>  :uul  coiistitiitifiti  in  which 
th«i  vari«'tit'h  and  Hiilnvarit'tioH  ditfor  «lii:htly  frnrn  e.'i»'li 
other.  I'Ik'  whole  or;:.iniMalion  seems  to  h.ive  herome 
jihistic,  imd  tends  to  (lepart  in  some  «mall  dej^'ree  froi.i 
that  of  the  |>irental  type. 

Anv  v!ir  ition  wliuh  is  not  inherited   is  iinimportiint 
for  us.      I'»ut   tlie   nuinh«T  and   diversity  of  inheritaMo 
deviations  of  stnictii  re.  iiolii  those  of  slijrht  and  ttione  ot 
cnnsideralile  phvsicdotfifAl  imporUnee,  is  endless.      I>r. 
Prosper    i.ucas  s  treatise,  in  two  hirjfe  volumes,  is  the 
iiillestand  ttie  ».est  on  this  suhjoct.      No  hreederdouhta 
liow  str«»nir  is  the  tendency  to  inheritAiice  :  like  produces 
like  is  his  hjiidamental  helief :  douhts  have  heen  thrown 
on  tliis  principle  hy  t»'eoretical  writers  alone,      \\hen 
any  deviation  of  structure  often  appears,  and  we  see  it 
in   the  father  and   child,  wo  cainiot  tell  whether  it  may 
not  lie  due  to  the  same  cause  having  acted  on  both  ; 
hut  wlien  amonjist  individuals,  apparently  exposed  to 
the  same  co-idilions,  any  very  rare  deviation,  due  to 
<n'iw    extraordinary    co'mhination    of     circumstances, 
appears  in  thejtarent  —say.  once  amonjrst  several  million 
individuals -and    it   reap'pe^ira  in   the  child,   tlie   mere 
doctrine  of  chan."s  almost  compels   us  to  attrihute  its 
reappearance   to    inheritance.       Kvery  one   must    have 
heard   of  causes  .>t  alliinism,  prickiy  skin,  hairy  hodies, 
etc.,  appearini:    in  several  memhers  of  the  sjime  family. 
If  s'trantro  ana   rare  deviations  of  structure  are   truly 
iiiliorited.  less  stran^re  ■itid   commoner  devi.'.tinns   may 
he   freely    admitted    to    he    inheriUihle.       I'erhajis    the 
correct  wav  of  viewiiij;  the  whole  suhject,  would  he,  to 
Inok  at  the  iiiheritance  of  every  character  whatever  as 
the  rule,  and  non-inheritance  as  the  anomaly. 

I'he  laws  ijoverninu'  inherit;iiu*e  are  <|uite  unknown  ; 
no  one  can  say  whv  a  peculiarity  in  different  individuals 
of  the  same' species,  or  in  individuals  of  ditlerent 
at-.«."p2  js  ^uTr-.oti'ne.s  inherited  aiid.  sometimes  not  so  ; 
v*'hy  the  child  often  reverts  in  certain  characters  tr 
its  grandfather  or  ^rrandmuther  or  other  more  remote 


Mt     :i/^^.^^^^«i^ 


VAIUATION  INDKR  DOMESTiCA TION      i;, 

"u-^rt;,"!;?;/'  ''""'"7^^  '"  "^""  t— "tted  from 

"li-  M.  th«.  ruHlrs  of  uur  d.mu-stic  br,'..,|H  ,-»r,.  ofVn  trl 
ra.Ued  e,ther  exclu.iv.ly.or  i„  a  „mh-1,  .rirt.Xr  "  : 
•ii.''*  alone.  A  mn.h  more  imporUnt  rule  hJ  .h  r 
t»'  Mk  may  Ue  trnHtc,,!,  m  that,  at  ihatewr  ,  eriod  i,' 
;'  l-ouhanty  aH...arH.  it  t.,..!.  to  ap,...,.r  u/tre  1  .r  ,^' 
.     .  co,,,,j„.    ,„.^,  U.ou,.h  sn'oletimos  oar   ,V       n 

'».er,t.,i    oerol.anti..,    i„  the    horr.s    of  ratt  e    n.  ,1 
M'l-ar   only    ,n    th.    orf.pri...    v,f,..„    „.,,Hv    ^ 
.'-"l'HntM,s  Hj  the  silk.orm   are  known        a,   '^ 
'"«'   '••.•rrespon.ln.sf  cater,„|lar  or    cocoon    ^t^i-  .'      M 
'.CMe,|.tary    ,i,..as,.s   an.l'  .o,„e   other      :.t:,"ke   n  . 
i'«;li«ve  tfiat  the  rule  ha.  a  wi.ler  evu-r  '.h.      ,"  I    t^^ 
v'I.erj  there  is  no  apparent  reason   .;''''  :..;;.';''; 
>lmuhl   appear   at  any   particular  a^^e     A-t  tint        I     ■ 
t"".'l  to  appear  in  the  iffsprin^  at  th;  l. mj  1    , ,     I'r 

u  the  crossed  orfspnnir  from  a  short-horned  cow  hv  ^ 

I  ad      II.        .'.'*''":"'''•-'   ^■"'■i^ties,  „hen   run   wild 
!.rad   ally    hut    certainly    revert  in   character   to  the  ; 
.|l'or..nnal  stocks.      Hence  it  has  heen   ar.ned   that  1 

';^.^:^'!.:^r  "?•  .   '   »--  -  --  endeavou/ed  S 


Ijaij  .' 


icisive  j.n  in   liie 


■^o  of^en  and  so  holdly  heen  ma«ie.     'II 


?T&it  dithculty  in  proving  its   truth 


a|)ove    statement 
lere  would  l>e 


we    may    Kafely 


14 


ON   THE   ORIGIN    OF  SPECIES 


ronclude  that  very  many  of  the  most  stroiitrly-marked 
Jtiinestic    varietiert    could    not   po^siMy  live  in    a  wild 
■;tate.       In    many   cases    wo    do   not    know    what    the 
ihori^inal  stock  vvas,  and  so  could  not  tell  whether  or 
not  iic.irlv  perfect  reversion  had  ensued.      It   would   he 
(juite  neces>ary,  in  order  to  prevent  the  ettects  of  inter- 
cnissini;,   thai' only   a  sini^lo  variety  should   he  turned 
loose  in  its  new  home.      Nevertheless,  as  our  varieties 
certainly     do    occasionally     revert    in    some   of   their 
(haracti'rs  to   ancestral    forms,    it    seems    to    me    not 
niii>n»h;il)li>,  that  if  we  could  succee<l  in  natural i.-iiiir,  or 
were  to  cultivate,  durintr  many  ;renerations,  the  several 
races,  for  instance,  of  the  cabha^je,  in  very  poor  soil  (in 
which    case,    luiwever,   some    etlect   would   have  to   !»e 
attrit)ute<l   to  the  direct  action  of  the   nooi   soil),  that 
they  would  to  a  lartre  extent,  or  even  wholly,  revert  U) 
the  wild  aht»ritcinal  stock.      Whether  or  not  the  experi- 
nunt  would  surceed,  is  not  of  f^'reat  iniport-ance  for  our 
line   of  ar-^ument ;    for  hy  the  experiment  itself  the 
condition-  of  life  are  chani,^ed.     If  it  could  he  shown 
that  our  thmiestic  varieties  manifested  a  stronjjr  tendency 
to    reversion,— that   h,    to    lose    their   acipiired    char- 
acters, whilst  kept  under  the  same  conditions,  and  whilst 
kept  in  a  considerable  body,  so  that  free  intercrossing; 
mijrht  check,  by  Mending  'tofjetlier,  any  sliii^ht  devia- 
tions in  their  structure,  in  such  case,  I  jrrant  that  we 
coul''  deduce  nothing'  from  domestic  varieties  in  regard 
to  si)ecies.     Hut  there  is  not  a  shadow  of  evidence   in 
favour  of  this  view  :  to  assert  that  we  could  not  breed 
our  cart  and  race  horses,  long  and  short  horned  cattle, 
and  poultry  of  \arious  breeds,  and  esculent  vegetables, 
for  an  alniost  infinite  number  of  generations,   would 
he  opposed  to  all  experience.     I  may  add,  that  when 
under  nature  the  conilitions  of  life  do  change,  varia- 
Li'J-;s  and    rever>i(in>  uf  character  picbably  do   occur  ; 
but   natural  selection,  as  will  hereafter  be  explained, 
will  determine  how  far  the  new  characters  thus  arising 
sha'l   !>e  i.Tc^^'T^ od, 

W'hen'.ve  look  to  the  here<iiUiry  varieties  or  races  of 
our  dome^tic  animals  and  plants,  and  comjKire  them 


^v, 


■•»",>la'*!' 


m 


t; 

I 


VARIATION  UNDER  DOMESTICATION      16 

-ith  closely-allied  spccie-s,  we   Renerallv  porreive    ,n 
"(ich    domestic    race,    as  already    rennrU/ll 
'orm.ty  of  character  than   i„  tn.o  m^    es  ^'     tm.e  ti" 
-.•es  ot  the  san,e  species,  also,  otle,!  lu  ^e  a  I^ZXa 
monstrous  character  ;  hy  which  I  mean,  that    u    In    : 
.  hjern...   from    each   other,  and   from  otle     ^l   '  t  ^ 
t  ij  sar.ie  trenus,  n.  several  trilling,  respects,   tl  ev     ,  te 
a^rfor  ni  an   extreme  de^rree  in^on.e  one     ar        ot 
-hen  compared  one  with  another,  and  more'espec 
nlH,„  compared  «-.th  all  the  .pecies  in  nature  twf. 

wth  hat  ot  the  oerfect  fertility  of  varieties  w  „ 
.  n.ssed  a  suh,,e.-t  l.ereafter  to  he  discussed),  d,,,  es  j  c 
r_Ke>  ot  tue  .same  species  ditfe.-  from  each  ot  e  t  ^e 

jame  marn.er  a.s,  only  in  „,ost  c.ise«  in  a  lesse    de..ree 
than,  do  closely-alhed  .pecies  of  the  .vime  -enus  m  ^ 
st.ite  of  nature.      I  think  this  mu..t  he  adnnUe      w  en 
Tm.  ;;:;^t    f  ''''?  "^  ^^^Y^^-^  any  do„H.stic"a     ''e^t t 
rSlyrm^^enT^&J-L^ 

»t,itU  that  domestic  ra,cs  do  uot  differ  from  ea, 
otlier  „■  cliaracterB  of  ffonerie  value.  I  think"  eou] 
l«  sliov,,,  that  this  statement  i,  hardlv    'ima     S 

turnl    T^*"  ''"*'"V"  ^-^  estimate  the  amount  of  struc 
tiiral    difference    hetween    the   .lomestic   ri  es   of 

S^:^~".;^rSe;;d^r'Si? 
-uid  he  sh„»„  that  u,e  ^e>-h;„;i;d!"h;";di,ruj,' 


le  ON  THE  ORIGIN   OF  SPECIES 

terrier,  spaniel,  and  buU-dmr,  which  we  all  know  pr<v 
Se  tbeir  kind  bo  truly,  were  t 'e  offspnns  of  a^ry 
Sle  species,  then  such  facta  would  have  trreat  we.^^ht 
i      mak  ng  us  doubt  about  the    immutability    of  the 
n  a,^  very  closelv-allied  .mtural  spec.es-for  instance 
o       e  n.ai.v  foxes-inhabiting  different  quarters  ot    he 
«or Id      I  do  not  believe,  as  we  shall  presentlv  see,  tha 
he  wbole  amount  of  difference    between  the  sever^ 
hreeds  of  the  doi?  has  been  produced   under  domestica- 
ti  ml  believe  that  some  small  part  of  the  d.tference  i8 
due  to  theii  bein^r  descended  from  ^^f  "^^V^^P^^''^,;-  /" 
the  case  of  some  other  domesticated  «P««^|f '/''?/«    ^ 
..resumptive,  or    even    stron,,   evidence,    that  all  the 
bretds  have  descei    .'d  from  a  sinj^le  wil  •  stock. 

11  ha.<.rten  been  assumed  that  man  aas  chosen  for 
aomesticati..n  animal,  and  plants  having  an  extra. 
or  Imarv  inherent  tendency  to  vary,  and  likewise  to 
wi  nd  diverse  climates.    I  do  not  dispute  that  these 

ran- cities  liave  added  lar-ely  to  the  value  of  most  of 
riiomesticated  productions  ;  but  how  could  a  sava.e 
possibly  know,  when  he  first  tamed  an  animal    whe    e 
it  would  vary  in  succeeding  generations    and    Nhetber 
would  e.ulure  other  climates  .;     Has  the  little  vana- 
ility   of  the  ass  or  guinea-f.,wl,   or  the  small  pjm^r 
/endurance  of  warmth  l>y  the  reindeer    or  of  cold  by 
the    common   camel,    prevented   their    domestication 
cannot  doubt  that  if  other  animals  and  plants,  equa^ 
n       u    ber    to    our    domesticated     productions,    and 
elongng   to    e.,ually    diverse   classes   and    countries 
ere  fiken  from  a  state  of  nature,  and  could  be  made 
o   hreed     or  an  equal    number  of  generations   under 
l"  mestication,  they  would  vary  on  an  avera^a-  as  largely 
tTlu- parent  spec'les  of  our  existing  domesticated  pro- 

'"^n 'X'^r'^^tost  of  our  ancienUy  domesticated 
anna  and  plants,  I  do  not  think  it  is  possible  to 
^"'"  :./..„.  H«h,ut«  conclusion,  whether  they  have 
i^si^nde.!  7r..m  one  or  several  wild  snecies.  The 
a  ^imeiit  mainly  relied  on  by  those  -»'«  - '«^«  "  *^« 
multiple  oritfiu  of  our  domestic  animals  .8,  that  we 


VARIATION  rXDEK  DOMKSTK  ATJ(  )N      17 

finri    in  tliP  r.M.st  Hunout  records,  nu.ro  espo,  aJlv  on 

and  t  at  some  oMl.e  breeds  closely  resemlde,  pc'  ha  ,J 
.-e  ideMtical  v,,tl,,  those  still  exi'.tini,.  Kv  .„  if  th  ' 
-.ner  fa.t  uere  tuuMd  more  «trictlv  and  ^^ener,  I  true 
't..-^n  see,,,,,  to  n.e  to  he  the  ease,  what  diH-^  itlhow 
nut  that  Kon.e  of  ..ur  hree.is  on.n'.KHled  t  leTe,  fo,  r  «; 
^  ve  thousand  years  a,.> :  |i„t  Mr.  Horner's  re'se^n^.^ 
1'"  •-•  re.Hiered  ,t  m  some  decree  prohahle  thaf  n  a^ 
^.Whnently  nvili.e,]  to  have  manufaetu  ed  n  .trerr 
ex.sted  m  the  valley  of  the  Nile  thirteer/or  A  urteoJ 
-.u.a„d  years  a,.o;  and   v  ho  will   pretend  to  Ty  £ 

rra  d..]   j.  ,„.^.„  „,  ,Vusti  dia,    who    possess  a  8emi- 
<i'>  '  t'.tic  doir,  may  not  l.r,      existed  in  Wvpt  > 

Jhe  whole  suhiect  must,  1  think,  remain  va^ue  ■ 
nevertheless,  may,  without  here  ^n.^rin^"  o,?^!"' 
dt  ta.ls,  state  that,  from  peo^raphieal  and  r^her  rtm 
M.ieratH.ns  J  think  it  hi,.hh*  prohahle  t  at  or 
don...st.edofrs  have  descended  from  seve  U  wild 
P-.es  Known,..,  as  we  do,  that  sava-^'s  are  ve  > 
fond  o  tanun..  ammals,  it  seen.s  to  me  unlike  in  Je 
s  .?//"  '-'--^^onus,  which  i«  distrihuted  i/awild 
Ktate    throu.^hout    the     „„rld,    that    since    man    firs 

'  >  "le   I,)  Mr.    IJlyth,  on  the  hah  ts,  voice    and  rn„ 

I'-lieve  tl.arthese  l.tter  lir     ?     '"""'Patent  jud^., 
J'.^rent      \\  it  ,  ro    ^  f  .     1       had  more  than  one  wild 
I  .rcni.      n  ,n,  re,,i.ect  to  liorses,  from  reasons  which  I 
cannot  true  here,   i  am  douhtfu  Iv  inclimn  lo  S 'v. 
in  <>PI...Mt!on  to  several  authors    tl.at  nil    I  ''*'^'^*^*-' 

^--ended   tn,n>   one  wild   stock      1,'r        h-tT'^w^" 
:'l:-::-;  '-»,  his  h.^  and  varied  .to^s  of  illl^.^r 

■  •■..*A\i   *itiijt*    iiifift*   iiiin  #1...*    ,1-1  .  .      ^      ' 

iniost  anv  one.  thinks 


•'"t  all  tht  hreedsofpoultr'vL...    

»-ommon  wild  Indian  fowl  (('alius  hank 


lave  proceeded  from  t} 


le 


iva).      in 


reicard 


#: 


•.;r^:.-^  r' 


18 


ON    THK   ORIGIN    OF   Sl>K(  IF> 


n 


U)  (lucks  and  raldiits,  the  breeds  of  which  ditfer  con- 
Jii(ltT;il)ly  from  oacli  oilier  in  strm^ture,  I  do  lift  doul>t 
that  they  lirive  ail  descended  from  the  common  wild 
liuck  and  raltliit. 

The  do<-trine  of  tiie  oritjin  of  our   several  domestic 
races   from    several  ahori;;iual   wtocks,  has  hoen  carr'ed 
tu  an  ahsurd   extreme   \>\  ^omo  authors,      'lliey  l)elieve 
that  every  race  which    itrceds   true,  let   the   distinctive 
characters  he  ever  so  >iit:ht.  lias  had  its  wihl  prototype. 
At  this  rate  there  must  have  e.visted  at  least  a  score  of 
speciea  of  wild  cattle,  as  many  sheep,  and  several  eoars 
ii!  Kurope  alone,  and  several  even  within  (ireat  liritain. 
One    author    believes  that   there  formerly    existed   in 
( ireat  Mritain  eleven  wild  species  of  sheep  peculiar  to  it. 
\\l;en  we  hear  in  mind  that  I'.ritain  has  now  hardly  one 
peculiar  mammal,  and   l-rance   hut   few  distinct    from 
tiiose  of  <ierinany  and  conversely,  and  so  with  Huiijrary, 
Spain,  etc. .  hut  that  each  of  these  kingdoms  possesses 
sfveral  j)eculiar  breeds  of  cjittle,  sheeji,  etc.,  we  must 
iulmit   that   many  domestic   breeds   have  originated   in 
Kurope  ;  for  whence  could  tliey  have  been  derived,  as 
the.se   several   countries  do  not   jiossess  a    number  of 
peculiar  species  as  distinct  parent-stocks?     iSo  it  is  in 
India.      Even   in  the   ca.sc  of  ti;e  domestic  doirs  of  the 
whole  world,   which    1   fully   admit  have  pro! -ably  de- 
scended from  several  wild  species,  I  cannot  doubt  that 
there  has  been  an  immense  amount  of  inherited  varia- 
tion.    Who  can  believe  that  animals  closely  resembliua; 
tlie    Italian    ti^reylHiund,  the  bloodhound,  the  hull-dog, 
or   Hlenlieim   s]iaiiiel,  etc.  — so   unlike  all  wild  Canidae 
—ever  e.xisted  freely  iu  a  state  of  nature.''    It  has  often 
been  loosely  said  tliat  all  our  races  of  do<rs  have  been 
produced  by  the  crossing  of  a  few  aboriginal  species; 
hut  by  crossing  we  can  only  get  forms  in  some  degree 
intermediate  between  their  parents  ;  and  if  we  account 
for  our  several  domestic  races  by  this  process,  we  must 
i;<lmit  the  former  existence  of  the  most  extreme  forma, 

aa     -.uc     :-,itj;.-;:     g  i  t?_r  is- •••••■' -,    ' : - -• ,' 

in  the  wild  state.      Moreover,  tlie  possibility  of  making 
distinct  races  by  crossing  baa  been  greatly  exaggerated. 


VARf.vrro.V  L'NDKR  DO.MKSTICATION      >9 

I'htTC  r,in  hp  Tin  dn.jl.t    tint-  ^   r.-   ,  x 

'1-s.  individual   nun^r;;  ^,i.h';"''''''     -"'-*-"  "^ 

^F--.e.  '.ant:d;vrii:r"^ri'^Tr7-"^"'^ 

-     '.-I^-rahlv    and    ^J^^J'^^TV"'''  P"re  hro-ds 

^inple  enough;  hut  whonfT".  "^•^''•vth.r.s,.    ,eem., 

•no  with  a,.:.t!  or    or     ever!l  "   "'"'l^'-^"'^  ^^«   ^Tossed 

'-rath..    ..,;';;:;-  t^"^e^^.on.ed.H<..,,^,, 

'•^ en;    ,r.Hnrt    }  reeds      on  d  ^nTT'^""''^    '"^*"'*'*^" 

'•"'I  •->  sind  e  on    «:  .r     '  •''"'^    "''"'*""  •  ""'•  <•«"  ' 

!'een  th„:f„rmed  ^  ^  P«rn,anent  race  havintj 

have,  aft.r  del  1  orat  .n  r.k-  "'  "^"'f  ^f'*"'*'^^  ^'"""P'  ' 
'    ''-•"    '-F't   e  or     Cd   whiU'^r  ''"T'^^''"    f*''^'^"- 

^V-m  several  <,..ar  e^  o/  TL  I  '  •'.  ""'""'^  "'*''  ^"^'"^ 
tf)"  FIo„.  U-  *FM  orfrL  -  ^•"■''''  "'"'•e  especial  I V  hy 
>'-ray    r>on,     iw  >"^,C  ^^'  -f   »>>'  the    Hon.(^ 

l-'n.uaees  have  heen  .uld  shed  T  "  '"  ''''^^'■'^"* 
o'    thorn  are  very  im,.  r       f  "■  P'^'*'''"^  «"d  .on,.- 

«''ti■|.-:U^      r  ^^veT.  'T   ^""-^  "^'  ^""^i<lorah!e 

^•'^"^■-rs  and   have  h'^''*     ^  ^'*^'     "^''^'^^    «'"i"'*"t 

-'nnnhi,,.  a.t.  n  s  In^'      r         '^"'*"'"'i^>'  "'^  ^^'^  ^^'-^'"'^  '"^ 
-Hi    the  ;},or    ft  ;^^^^^^^^^  f-^-'^'lish  .arrier 

Hiri-on.,u-e.  i,   their    kuHn  '"'•"-     '•'>'-'-«^^Po,ulin.. 
L.  .Ionn,ll.  '.I-'.;''.""'  remark-aide  from  the  wonderf,.! 

""  this-;.  .;;,-;:;,:::^'t;;:'i;^::^.fi<^i-^       .,.ad; 


ices 


to  the  nostrils,  avA  a  »nd« 


I 


■t 


I 


2f.  ON    rHE  ORKilN    OK  SPKCIES 

^'•p^  of  inoiitli.  Tlic  phort-farod  tuinhltT  lias  a  iicak 
III  oiilliiie  iilnutsi  like  tli.it  of  a  tiiich  ;  aii<l  llio  ("Oimmni 
liirn'liliT  has  tliP  sini.Mil.ir  irilierited  li.'ihit  of  liyiuf.'-  at  a 
j^r«'at  heitilit  in  a  coiiij)act  llock,  and  tiiinhliiitr  in  tUo 
air  lipaii  over  heels.  The  runt  in  a  iiinl  ot  t  real  size, 
with  luntx,  massive  heak  and  lar^^e  irel  ;  Borne  of  tiic- 
8ul>  liree<ls  of  runts  have  very  lonjr  necks,  otiiers  very 
lon^  wintrs  and  t'uis,  dIIhts  sinuularly  short  ta'ls. 
The  harh  i-  allied  to  t!  •  carrier,  liu».,  in.-tcad  of  a  very 
lon^'  heak,  has  a  verv  !=hort  and  very  hroad  one.  Hie 
pout«!r  has  a  much  elon;:ated  ))ody,  wiiiL's,  and  lep*  ; 
and  its  enormoubly  (levelo]»ed  croji,  which  it  tfioriet- 
in  infhiiinj;,  may  well  excite  a.-tonishinent  an<l  even 
lauirhter,  'lite  tiirltit  has  a  very  short  and  conical  heak, 
with  a  line  ol  reversed  feather.-  dowTi  the  lireast  ;  and 
it  has  the  hahit  of  continually  exiiandinir  slitrlit!)  the 
ujijter  i>art  of  tlie  trsophaeus.  'I'he  .>at oldii  has  the 
feathers  so  much  reversed  alonj:  llie  liat-k  of  the  neck 
that  they  form  a  liood,  and  it  liaii.  f)rM|Kirtioriatly  to  it>> 
size,  much  elon^-ated  wiiifr  and  tail  feathers.  'Hie 
trumpeter  an<l  lautrher,ap  their  names  express,  uttei"  a 
very  ditierent  coo  from  the  other  lireeds.  The  fantail 
has' thirty  or  even  forty  Uiil  fe'.tliers,  instead  of  twelve 
or  fourteen,  the  normal  numher  in  all  memhers  of  the 
fieat  pifreon  family  ;  and  these  feathers  are  kept 
expanded,  and  are  carried  so  erect  that  in  i:oo(\  hirds 
Uie  ii"a(land  Uiil  touch  ;  the  oil-^land  is  <juile  ahorted. 
Several  other  less  distinct  hreeils  mitrht  he  specified. 

In  the  skeletons  of  the  several  lueeds,  the  develo]>- 
meut  of  the  hones  of  the  face  in  leiiji-thand  hreadth  and 
curvature  differs  enormously.  I'he  shajie.  as  well  as 
the  hreadth  an.i  lentrth  of  the  ramus  of  ilu-  lower  jaw, 
varies  in  a  highly  remarkahle  manner.  The  numher 
o!'  the  caudal  and  fvicral  vertehra*  vary  ;  as  does  tiie 
huinlier  ot  the  rihs,  together  with  their  relative  hreadth 
ami  the  presence  of  jirocesses.  Tiie  size  and  shape  of 
the  ajtertures  iu  the  ^ternum  are  hitrhly  varialde  ;  so  i.« 
/I i y/\»-.?-.»»»f^;»   ?\!id   rel-^t'.ve   s.i/e  of    tliO  two 


arms   of  the   furcula.       I  he  proportional  width   of  the 
^-f^pe  of  mouth,  the  proportional  len^^th  of  the  eyelidH, 


VARIATION  UNDKK  DOMESTK  ATIOM      H 

■>t   the  (.ritire  t.ftlif  nostrils  or'tlio  K.ti::iie  (not  aiwavs 
in  >trict  corr.'I:iti.ui  with   the  li'ii-th  of  lieak),  tli.)  ^ka 
of  the  crop  an. J  of  tho   npj.flr  prirt  of  tht«  ..-sophair-n  ; 
!jit«   ilpvploptn.'iit  ;iiul  ahortion  of  the   oil-i,'l,in<|  ;  "  the 
nufTihcr  r,f  tho  primary  wintf  ati.l  caudal   f.vithers';  the 
r.iativo  h'Uizth  of  wiiiir  and  fill  to  each  other  and  to 
t(iol)ody;  tho   roI.iti%-e   length  of  Iva  and  of  tho  feet  • 
die  nnmher  of  sciitell*  on  the  toes,  the  deveh)pfiient 
ot  sKui  h.-tween  the  toes,  are  all   points   of  structure 
whic},  are  vinahlo.      Tlio   period   at  «inch    tlio  perfect 
plurnriire    is   acunred    varies,  as   does   the  state  of  the 
down  with  which  tho  nestlintr  hirds  are  clothed  when 
hatched.      1  ho  shape  and  size  of  tho  ec'^s  vary       I  ho 
marnier  of  flitrht  differs   remarkahly  ;  as  does'iii  so,„o 
t.r-c  s   tho   voico  and   disposition.      Utitly,   in   certiiin 
breeds,  the  niah-s  and   female,  have  come  to  ditfer  to  a 
lUitrht  dcjrree  from  each  other. 

Alto-ether  at  least  a  score  of  nitreons  mi^rht  he 
cho-en,  which  if  shown  to  an  ornithofotrist.  and  he  were 
told  that  they  were  wild  hirds,  would  certainly,  I  think 
t)e  ranked  hy  him  as  well-defined  ppecies.  Nioreover' 
I  do  not  helieve  that  any  ornitholotrist  would  place  Uie 
hnt'lish  carrier,  tho  short-faced  tumhier,  the  runt,  the 
harh,  p..ut«r,  and  fantail  in  the  same  «;enus  ;  more 
especially  as  in  each  of  these  hreeds  several  truly- 
iiiiiented  sub-hreeds,  or  species  as  he  mitrht  have  called 
tiiem,  could  he  shown  him. 

tJreat  a.s  the  differences  are  between  the  breeds  of 
piireons,  I  am  tully  convinced  that  the  common  opinion 
ot  naturalists  is  correct,  namely,  that  ail  have  de- 
s<  ended  from  the  rock-pigeon  ((  olumba  livia),includiM/ 
under  this  term  several  s:eoirraphical  races  or  sub- 
■^pecies,  which  ditFer  from  e^tch  other  in  tho  most  triMir'ir 
resj,ect,s.  As  several  of  the  reasons  winch  have  led  r.ie 
to  this  belief  are  in  some  de<,^ree  applicable  in  other 
c-.-es  I  will  here  briefly  ghti  them.  If  the  severiJ 
I'l-oeds  are  not  varieties,  and  have  not  pr-r-oeded  from 
■-.:■■■■'  rorK-piaeuii.  Liiey  must  hav«  descen.led  from  at 
lea^t  seven  or  ei-ht  aboriginal  stocks;  for  it  Ls  iir^ 
po>riit>le  to   make  the  present  domestic  breeds  by  rl4# 


^ 


2? 


ON    THE    ORKJIN    OF   S1'K(  lES 


I 

I 


cio-.sii,4/  of  aii\  ioss('r  nuiiilitr:  hovv.for  iiistarif.-,  could 
a  fMiiiUT  !k-  pruduct'd  hy  iro>,,r;j  two  Kr.'f.iv  uiiU-s>  o:ie 
of  till-  iKf.-Mt-stnckb   pus.--e.-,seu  thf  clirinu-len^tic  euor- 
m«.u-   LTdj,.-       llm    supposed    al.(>r;-ni,il    storks    must 
alJ    iiavi-    U-.Mi    rock-pit'fi.us,  tli.it    i>,  uoi    iin'»>dii,jr  or 
williiii.'iy  perilling  on  trees.      tJut  besidtw  C.  livia,  with 
lt«   ^-»M.:,rr:ipIn.al    sub-spe.;ies,  only   Iwn   or   three  otiior 
speeies  ul  rork-pit^eoiis  are  kiiovvij  ;  and  th.-M-  have  ii..i 
any  ot  tlie  cliara.fers  (j(  tiie   domtstic   iireeds.      Hen.e 
tlie  supp.iMMJ  ai.ori.riual  blocks  muM  either  still  exist  in 
the  countries  where  li.ej    vvere  onuniaJU  uoinesticated, 
and  jet  ho  iinkno>\n   to  ornitholotMsts  ;  and  this,  .on- 
>iderinir  tluir    si/.e,  hahit>,  and  reniarkahle  characters, 
soeiiiN   very   imjirohahle  ;   or   thev   must   ha\e  he.,,n.e 
extinct  111  the  wild  state.      Hut  hirds  hreedin^r  on  preci- 
pices, and  ^r„„d  tliers,  are  iiulikelvto  he  uxterniinai.jd; 
and    the    common    rock-[»i«:eun,   'wliich    has    the    same 
hahits  With   the   domestic   hreeds,  ha.,   not    heen  exter- 
minated even  on  several  of  tht  smaller   IJritish  islets, 
or  Oil  the  chores   of  the    Aiediterraneau.      Hence  the 
supposed     extermination    of   so   manv    species    havin>< 
sim.lar  hahits  with  the  rock-pitreon  seems  lu  me  a  vcy 
rash  assumjjtion.      Moreover,  the  several  above-named 
d«.mesticat.MJ  hreeds  have  been  trausporte«i  to  all  parts 
ot  the  world,  and,  therefore,  some  of  them  must  have 
been  carrietl  hack  a^ain  into  their  native  country  ;  but 
not   one    has    ever    iiecome  wild   or  feral,  thougii  tlie 
dovecot-pijreon,    which  is  the  rock-pij^eon    in   a    very 
slif,'htly  aiucrtti  state,  has  become  feral  iu  several  placets'. 
Ayain,   all     recent    experience    shows  that  it  is  most 
diliicult  to  ^^et  any  wild  animal  to  breed  rreeiy  under 
domestication  ;  yet  on  the  hypothesis  of  the  multiple 
oriffiu  of  our  pi^^eons,  it  must  he  assumed  that  at  hvi^i 
seven  or  eijrht  species  were  so  thon.uehly  domestic*»ied 
in  ancient  times  by  hali-civili=ed    man,  as  to  be  ^uite 
proliiic  under  continement. 

Au  arjjument,  as  it  seema  to  me,  of  trreat  weijjht,  and 


=e-'erhl  other 


s_>ecitied   breeds,   thou^-^h  a^rn-ein-'  ^'eneraliv    m    cou- 
BtitMtum.  habits,  voice,  cohiur.nji:,  and  iu  mo>t  jiarts  of 


VARIATION  L'XDKH  DOMESTICATION     2.1 

tl.:f  ^rrurtnrP.   with    the    wild    rock-pi-oon     vet   ar« 

.  t  fim.lv  of  (  oluM.lmhe  f„r  a  Leak  like  that  of  th». 
..^^I^h  .-arn.r,  or  that  of  the  short-fare.l  tmn  .ler  "  r 
Mrh:  h„.   nMersnl   feathers  like  those  of  the       c.hi, 

■u!  he.-„me  extu.ct  or  unknown.    So'm-  nv  str  m  1 
^.u.enne.s...nnon,ei,npn.l.ahlein\rh^^^^^^^^ 

N.mo  tarts  in  re.Mnl  to  the  ...Innrinj.  of  ,„.r,,,  ./„h) 
.  ;^erve  oonsHieranon.      Tl.e  n,..k-p::,o;;„  i^'-T^Uw 
'"it.  an  I  has  a  white  n.mp  (the  Indian  suh-<„eeies    r 

';:::;r^.^^::'.::^r'^'-''^'^-i''^'ti.,.,i.h,  tii:^ 


on 


— ".;;.i  .i.;rk  ,„.  wmV,,,;'  li^^ . '    :    /J '    ,    „ 

.■■<  erually  e,lt.e,l  with  while:  the  «,„.,  h,,ve  t„  ,  M    ." 

InilyiMhl  liree.U  have,  hesid„  the  two  hH.-!,  ]  ,  ,il- 
"...».» .heciuer.,!  will,  |',|.,„|,.  These  °e  er'  I  nS.  .ta 
.■;     o..c„  ,       ther  i„  .,„y  „ther  «,«ne,  ^f  Ztlt 

I  cros..e(l    some    uniforinlv    white    fant-iik    w// .  ' 

'iinforniK.  M     1,    i     i        •     ,  '""-    'aniaijs    with    some 

•":;;•  ™!;,i  it.!; »;  t..^'i  i'z^^':^rL  -T' 

pire  black  h;.rl,  was  of  a^  heaiitifijl   a  ^.l—  ^-i....-    ^  ". 

^■^^itix:;?^  f"";!''  '^^•^'^  wuu;-ha;:an,iwn;i;;;d 

Mi^e_flfre«J  Uii]-teathers,asanvwild  rock.rmrei.n  i    U« 
-.  under^nd  the^  fact.,  on  {he  vrell-k^Vw^illnnciple 


»;<--■  -i-  T,"c3^ 


;l 


24 


ON    If  IK    ()KI(;iN    OK    S|'K(  Ih'^ 


of  rovers:. .11  to  aic-csiial  .li.irarter'^,  if  ill  tlio  donio^tic 
Itn-fil-.  li.i\n  (le><»'ii(iiMl  fruiti  iliu  n)(K-ji!irc(iii.  I'mt  if 
wii  (li'iiy  this,  wi>  iiiiisi  tii.ikt'  tino  of  tlif  two  follow  injf 
luLrlily  iiii[iroli.il)l('  sii[.|.(.->itions.  K:iin'r,  firstly,  tlint 
all  the  s«'\it;i1  itiiauiiii-il  ahoriiriiiai  storks  were 
coloiiroil  and  iii.irkcd  i.kc  tlit;  rofk-|ii::ci>ti.  althoiii.'h  no 
otluir  exNtiiiLT  >in'<ic,s  is  thin  coh.urfd  iiid  marki-d,  so 
tfi.it  in  wich  -I'parato  tin'cd  tlifrw  initrht  !k*  a  tciidericy 
to  revi>rl  to  the  very  wiinu  colr.iiis  and  niarkiiiirs.  Op, 
secondly,  that  each  l>re«'d,  even  the  pure-^t ,  has  within  a 
d»t/eii  or,  at  nio.st,  within  a  M-nni  of  irenerations,  '.eea 
crossed  hy  the  rock-[>ii,'eon  :  i  s;iy  within  a  do/eii  or 
twenty  generations,  for  w«  know  of  no  fact  coiinteii- 
.Tiicini,'  the  helief  that  tlie  child  ever  reverts  to  sonio 
one  ancf.tor,  removed  hy  a  trrealer  niirnix^r  of  genera- 
tions, in  a  hrt'i'd  which  lias  heen  crossed  only  once 
with  some  distinct  brei-d,  tho  tendency  to  reversion  to 
any  character  derived  from  such  cross  will  naturally 
hecome  less  and  less,  a-s  in  each  succeedinjr  ereneni- 
tioii  there  will  Ik)  less  of  the  foreij:n  blood  ;  but 
wlieii  there  has  U'en  no  cross  with  a  distinct  breed,  and 
there  is  a  tendency  in  both  parents  to  revert  to  a  char- 
acter, whicli  has  been  lost  durinj<  some  former 
tjeiieratinn,  this  tendency,  for  all  tiiat  we  can  see  to 
the  coiitrary,  may  be  transmitted  undiminislied  for  au 
iudefmito  number  of  K-enerations.  Ihese  two  distinct 
cases  are  often  confounded  in  treatises  on  inheritance. 

Ivistly,  the  hybrids  or  nioiifrrels  from  between  all  the 
domestic  breeds  of  pij^eons  are  {>erfectly  fertile.  I  can 
state  this  from  my  own  observations,  purposely  made, 
on  the  most  distinct  breeds.  Now,  it  is  difficult, 
nerhaps  impossible,  to  brintr  forward  one  cA.se  of  the 
hybrid  orisj)rinir  of  two  animals  clairly  <li.stinct  beinj? 
themselves  jierfectly  fertile.  Some  authors  believe 
that  l()n>j:-contiuued  d*  mesticatiou  eliminates  this 
stroiitr  tendein!y  to  (terility:  from  the  history  of  the 
doiT  I  think  there  is  some  probability  in  this  hypothesis, 
if  applied  to  species  closelv  relatt-d  toirether/thouirh  it 
is  unsupi)orteil  by  a  sinirle  experiment.  Hut  to  ex- 
teud  the  hyjtothesis  so   far  as  to  suppose  that  speciea, 


■       'ii'Vi-ral 


VAIUATIOV  (JNUKK  [K)MF:STI('ATI0N      U 

vljoniririally  as  distinct  i»8  carriors,  tiiml.lors,  nouters 
\u>\  f;iiiUilH  now  are,   hI.ouI.I    viel.i   r.ff.j.rintr   p.-rtei  tlr 
f.-rtile,  iuf>T  »r.  sot'rns  to  ri..'  ra>l.  in  tli."  Hxtn>nu'. 

Jrom  t}u«H«  .^everiil  rousonH.  naiiu«iv.  tliB  improl.al.ility 
-»f  man  liaviri:r  foiiii.-rlv  trot  Mjven  or  pijfht  Mipposcd 
.[Mvif^  of  pi-roriH  to  i.rr.'d  tr.M-lv  uii.ier  dono'sUca- 
'-ion;  these  Mi|.p..vf.,l  s(>..,■i..^  hfitu;  ,,„ite  unknown  in 
I  wild  .^tate,  and  their  Ix-.omiinr  iio^*li,.re  feral  ;  tliese 
species  liavuii/  very  af.iiornial  charaeferH  in  certain  r»v 
|'pe<-tsasr..nip.ire<l  with  all  other  (  olunil.i<in..  tlioii^rl,  «„ 
liko  in  most  other  re^[.e.t^  to  the  ro.k-pi-ron  ;  the  blue 
roloiirand  various  rn.irks  ocrjuiionaiiv  a,.peann<,'  in  ail 
Iho  hree.i.s,  hoth  wJien  kept  pure  alid  whon  crosw'd  • 
the  monurel  otf-^prinj^  \n-,nyr  perte.-tlv  fertile  ;  from 
tliexo  several  rctsons,  taken  to-ether,  I  ran  feel  no 
•louht  that  all  our  donie>tir  breeds  have  descended  troni 
the  (  omniha  livia  with  its  jreoi^raphical  sub-species. 

In   tavour   of  this   view  ,  1    may   add,  firstly,   that  C. 
livia,  or  the   rock  i)i;reon,   has   been  found   capable  of 
domosticatu.n    in    Kiirope   and    in    India  ;  and   that  it 
agrees  m  habits  and   in  a  ^reat  number  of  pointj*  of 
structure   with    all    the    domestic    breeds.      Secondly 
aitlinuirh    an    Kuirlish    carrier  or   short-faced   tumbler 
differs  immensely  in  certain  characters  from  the  rock- 
pii,'eon,  yet   by  comparing  the  several    sub -breeds  of 
these    varieties,    more    especially   those    broutrht  from 
distant  countries,  we  can  make  an  almost  perfect  series 
b»>iween   the  extremes   of  structure.        Thirdly,    those 
characters  which  are  mainly  distinctive  of  each  breed 
fur  nistaiice    the   wattle   and    len>rth    of  l)eak    of   the 
carrier,  the  shortness  of  that  of  the  tumbler,  and  the 
number  of  fiil-f.athers  in  the  fantail,  are  in  each  breed 
eminently  variable  ;   and  the  explanation  of  this   fact 
will   be  obvious  when   we  come  to  treat  of  selection 
fourthly,  piireons  have  been  watched,  and  tended  with 
tbe    utiiio,,t  care,  and   loved    bv  many  people.      Ther 
have    been    domesticated    for    thousands    of  ve^rs    ia 


tjii.iftcnj    or    toe    Woriii 


;    too     earnest    known 


'u^T  ''^  l^"-"'«"«  '^  '"  t^'^'  Hfth  ^:Rvptiandvna-stv,  aboul 
<>«-«X)    B.C.,    aM    was    pointed    out    to    me  'by    I'rofesaor 


[ 


M 


ON   THK   OUKJIN    OF   SJ'h(  IKS 


H 


I^pHius  ;  hill  Mr.  Hircli  iiifnrms  mv  tJiat  pipeon8  are 
jfiviMi  in  a  liill  of"  fare  in  thf  |»ri'viiius  (Jvtiasty.  In  the 
tiriM)  ot'thti  KoriiaiiM,  as  w<-  ht-ar  fmrii  I'liiiv,  iriimctmp 
pru-eH  v»»Tfc  tri\«-ii  for  pif^r^oim  ;  <  nay,  they  are  fcuiii'  to 
lliis  yan'i,  lliat  they  fan  reckon  up  th»>ir  pfditrreo  and 
rai-e.  I'itrcons  wero  luuch  valiu'd  l»y  Akl.er  Klian  in 
India,  ahcdit  the  year  hluo;  never  le*-'  than  Jit.iido 
pi:,'('o:is  Mere  taken  ;*it}i  the  coiirl.  '  Jlie  tiionarchs 
of  Iran  and  Turan  sent  liim  H«)me  very  rare  hirds'; 
and,  continu<>s  the  courtly  historian,  ''llis  Maje-^ty 
liy  crossiiiir  the  hreeds,  which  method  was  ne  er 
practiced  heforo,  h.ix  improved  tlitim  astoniMliinjfly.' 
Ahoiit  this  wimo  |>erio<l  the  Dutch  were  as  e.i*:er  ahout 
piLM'oriH  as  were  tlie  old  itom.ms.  The  paramount 
iiiiporLiince  of  these  considerations  in  exftlainiiii,'  the 
immense  amount  of  variation  wliich  piireons  have 
underirone,  will  he  ohvious  wlien  we  treat  of  S«dectiou. 
^\'e  shall  then,  also,  see  how  it  is  that  the  hreeds  so 
often  liave  a  somewhat  monstrous  character.  It  is 
also  a  most  favourahle  circumstance  for  the  productinu 
ot  distinct  iireods,  that  male  and  female  pitreons  cau 
1k>  e.usily  mated  for  life  ;  and  thus  different  breeds  can 
be  kept  to^^etlier  in  the  sjime  aviary. 

1  have  discussed  the  proliahle  oriifin  of  domestic 
jtiireona  at  some,  yet  quite  insuthcient,  lenjfth  ;  because 
when  1  first  kept  piy:e(uis  and  watched  the  several 
kuids,  knowiii;;  well  how  true  they  hred,  I  felt  fully 
as  much  dilhculty  in  believing  that  they  could  have 
descended  from  a  cummn-i  parent,  as  any  naturalist 
could  in  comiiiL''  to  a  similar  conclusion  in  reyard  to 
the  many  spei-it's  of  finches,  or  otlier  laiffo  groups  ot 
birds,  in  nature.  One  circumstance  has  struck  me 
much  ;  namely,  that  all  the  tireeders  of  the  various 
domestic  animals  and  the  cultivators  of  plants,  with 
whom  I  have  ever  conversed,  or  whose  tre.itises  I  have 
read,  are  firmly  convinced  that  the  several  breeds  to 
which  eacli  has  attended,  are  descended  from  so  many 
.ihoriLTnally  distinct  species.  Ask,  as  1  have  asked,  a 
ceietirated  raiser  of  Hereford  cattle,  whether  his  cattle 
might  not  have  descended  from  long-horns,  and  be  will 


VAKIAIION  rVDKft  Do.MKSTK  ATK  )N      J7 

:M^h  you   to  Moru.      I   l,av«   n.-v.-r   ..u-t  a  Miireu,,       - 
;. -u  try,  or  duck,  or  rul-l.^t  fan.-.er,  who  w.m  :,.„  f' |,, 

;"  'M.nl  tlKit  earl,  ...ain  l,r«tvl  wa.  .lesr.  ...le.l  from  a 
.  >  Una  .,,c.-.,.s  \au  Mo.h,  iu  his  trrat..*,  .„  n,.ar. 
•i'.'l  apples,  shows  how  utterly  he  .lish-lieves  that  the 
-v.T.il  sort.,  tor  iMHtaure  a  Kihston-p.ppin  or  (o.llin- 
..,  |.le  couM  ever  Lave  pr.K-ee.le.l  from  the  seeds  ot  the 
■  .'"e  tree.  InminKrahie  other  e.va...pie,  .„wl.l  w 
-'.ve...  J  1.0  exphmat^on.  I  think,  is  simple  :  fron.  lon^- 
"  '""ue.i  .u.iy  they  are  stron;r!vimpn.s.e.l  with  the 
u.  ere..ee,H  hetvveeu  the  severar  raeL  ;  and  though 
t  >  Hell  know  that  ea.h  ra<-e  varies  sli::htlv,  for  thev 
;    a  theirpn/.e,  hy  sele.tn,^^  s.,rh  slij,ht  difteren.eM.  >et 

•V  Ignore  alUenerul  ariruments,  and  refuse  to  sum 
uj.  in  the.r  nunds  slight  ciirfereiu-es  arcumulated  durin- 
...  "iy  Huceess.ve  «eneraliouH.  May  not  thnse  naturar 
-i-  Hho,  knuwM.tf  far  le«.  of  the  lawn  of  inherita.ice 
-fan  does  the  hreeder,  and  kncwin,.  „o  mor.  than  1,^ 
'"«•'  of  the   interu.odiate    links    in  the    Io„tf   li,„,s   of 

uedeM  ended  from  the  «.:ne  parents- mav  they  not 
I'.irn  a  lesson  of  caution,  when  ihev  deride  the  i.lea  ./ 
^•.enes  ,n  a  8Ute  of  nature  bein^  lineal  des.-Ciidants  ot 
er  spetifi: .' 

^  U.J.  don.e.st,e  races  haye  been  produced,  o.ther  fV.-m 

V    ni  1      '^-T'^^  ^'''^'''  ''"••■'•■^-      •'^«""«  little  erf.  ct 
V  enf»I       ''I'/'*  ^^^"  '"te'^  t»  the  direct   action  of  the 

ne  Hould  he  a  b.>ld  man  who  w<.uhi  account  hy  urh 
.^.-ences  for  the  ditfererues  of  a  dray  and  a  r.u-e  liors.' 
■  ^eo?i  7,'  *';d  Woo.! hound,  a  carrier  and  tumble; 
I  .con  One  of  the  most  remarkahle  fealure^  in  ou. 
o>mest,cc;ed   races  is  that  we  ^e  in  them  adap    tion 

t"  m  nr; '"  '^';  ■■^"""'■^^■''  *"■  ^'^^""'^ »-"  ^^'^<  •-» 

ue  nroh.M  '"    •^""•'-     .^."^  ^'^'•i-'tions  useful  to  him 
■Z!;:::!'^."''^''  ^^,^^^\^-^y>or  by  one  step;  muiy 

:'*■,,        ^•>"'^S.«''H-h    cannot     be    rivalled    by    un^ 
"-.aauical  contnvan.e.  i«  ouiy  a   variety  of  the  wild 


r\ 


iP,  ov   TIIR   (iRKilX    OF   M'K(  lh*s 

DipsaciiH  ;  ,ii;:i  ttii-;  ;it7)i>iiiit  of  cij<ir.i,'e  may  liavo  sutl- 
tioiiJy  arisen  m  a  s.M'diinj-.  So  it  iia-  prohahly  Ixhmi  hIi}. 
tliM  turn-pit  doij  ;  ami  :liis  is  known  t<»  liavo  Ikm-ti  liiu 
>j;i^(<  witii  *iit"  an<  (in  sfuM']).  Hut.  wIhti  ice  compar"  tiiii 
'lray-hor-»»  a;.il  racf-hdr-e,  the  (ironuMlary  and  canioi, 
tliy  \ariiiiis  i.rt'cii.s  of  -lieoj)  tittcil  pi^'wr  tor  cultivattMi 
lari'l  i.r  riii)unt.ai?)  [vsturc,  wilti  tlio  wool  vt  ojie  hroi'il 
.(to.l  tor  oiii-  (iijrposri,  an;l  tfiat  of  another  hreeii  tor 
another  |iiirtMi-(>  ;  '.vhen  we  rotnparo  tlie  many  hree<l-;  of 
~.  each  lio.iii  for  man  in  very  dilfcn'nt  wav^  ;   w 'len 

'  iiiparf  the  ^^arne-cork,  so  pertinario'i^  in  liattle, 
'■"til  nljicr  lireeils  so  little  (iiiarn'lsoriie,  with  '  over- 
■■•  ii:  layers'  which  never  desire  to  sit^  and  with 
:.,',  hantain  ~o  r^rnall  and  eley:ant  ;  when  wo  eonipaio 
the  h(;>t  of  ;u:ri(!illiiral,  culinary,  orciiard,  and  ilowtir- 
j:,arden  race  of  plants,  most  useful  to  man  at  ditfcrent 
seasons  and  for  itiifereiit  purposes,  or  so  h(!autif'i!  iii 
his  eyes,  we  niu>f,  I  tliink,  look  further  than  to  mere 
variaifility.  W'e  cannot  suppose  that  all  the  breeds 
•vere  suddenly  produced  as  perfect  and  as  useful  i;8 
we  now  see  tiiein  ;  indeed,  in  several  cases,  we  know 
that  tiiis  has  not  hecn  their  history.  The  key  is 
man's  jiower  of  accumulative  selection  :  nature  yives 
^iicce>--ivB  variations  ;  man  adils  them  up  in  certain 
directions  uset'u!  to  him.  In  this  sense  he  may  ho  said 
to  make  for  himself  useful  hreeds. 

I'iie  ;;rcat  ['ower  of  this  principle  of  selection  is  not 
hy]tothc  ti<-a!.  it,  is  certain  lliat  several  of  our  eminent 
breeders  (lave.  tv--en  within  a  sintrle  lifetime,  modified 
to  a  lari^e  extent  -ome  hreeds  of  catti»i  ainl  sheep.  In 
order  tally  to  realise  wjiat  they  liave  done,  it  is 
aheost  iicces'^ary  to  read  several  of  the  many  treatises 
devoted  to  this  suhject,  and  to  inspect  the  animal.-t. 
Mreeders  habitually  speak  of  an  anitrial's  orj^anisation 
as  >omethini;  quite  plastic,  which  they  can  model 
almost  as  thoy  f)lease.  If  I  had  sj)ace  1  could  (juote 
numerous  p,a-sat:es  to  this  etfect  from  hiirhly  com- 
petent authorites.  Vouatt,  who  was  proliahly  lietter 
ru-<)ua!!ited  with  the  vvork.s  of  a^'-ricuituri.->ts  than 
almost  any   other   individual,  aud   who   vvas  himself  j 


VAJlIAiJOX  INDKK  DOMKSTK  A TloN      2: 

'Cry  trood  jud.ro  „f  „„  arrliriaK  ^(...aks  of  the  j.nn.-iple  ot 
'■i.vt;on  as  'that   «-),i,-h  enahl..s  the  ai:rinilti,ri,.t,  not 
:w_    to  nuxiify  the  ci.aractfr  of  his  /lock,  huf  to  chant'*' 
.'  alto-.-thor,      Jf  in   the  ina-ician's  wan.i,  hy  rn-ans  ui 
which   he    may   s.irnmoii    into   life  wh.levef   tnrin   and 
n.ouhl    he    i.ieases/       J.ord     N)M.ervine.    Kj-eakin-    of 
what  breeders  have  done  for  wlicej),  savs  :-'  It   would 
^■em  ,-is  ,f  they  had   chalked   out   upon' a   wall   a   form 
■  •TJrct  in    i(..,Mf,    and    then  had    pven    it    exi<tence  ' 
1  .-  ::  most  skilful   hroeder,  Sir  John  Sehriirht,  u-t'i\   to 
say,  witli  resj.ect    to   jctreonfi,  that    'he  w.uild   pro<iuc( 
atiy  triven  feather  in  tliree  years,  h^t  it  wul.;  take  hin, 
s.x   y»>ar:,    to  ohuain   liead    and    heak.'      Jn   S.ivonv  t!  .. 
imj)oriance  of  tt.e  principle  ui   selection   in   rc-a'rd    !,. 
iDeru.o  .heep  is  >.o  fully  recn-nised,  that  nieii  i,.ih)«  it 
"^  '|,  t;;"''*'-   tJ'i-  '^liwj.  are  placed   (ui  a  t.ihle  and   are 
Mudii':].  like  a  picture  hy  a  connois.-eur  ;  this  i-    done 
il.iec  tunes  at   intervals  of  months,  and   the  sheep  are 
c.h   time  marked   and  clas-ed,  so  that    tiic  verv    hest 
n:iy  uuunatelv  he  selected  for  hreediiiir. 

U  hat    Ln-lish    hreeders    have   actually    etf..cted     is 
['^'Y'"  ''>  ^'"*  «^'i<»rmous  j.rices  jriven  foranii,.aN  with  a 
irood  podi-ree;  and   these  have  now  heer;  expert ed   to 
f.lriM  4  every  (juarter  of  the  world,    i  he  impn.vement  i« 
t.v  n,.  means  K«'nerally  due  to  crossing  differeiit  hreeds  • 
al,    I  tie    he-t    breeder,    are   stron^rly    (.p{,o>ed    to    thi- 
i  r.Kticc.  except  sometimes  amont'st  cl«.>.-lv  aiiied  suh- 
yreed^.      And  when  a  cross  h.-s   heen  mad^.  the  closest 
MMecl,.,n  IS  far  ,-,,ore  indispensable  e\  en   than   inordi- 
nary rases.      If  M'iection  consisted  nierelv  in  .MM)arat:nt: 
some  very  distinct  variety,  and    hreediiiLr   fro,,'    it,  ih. 
i'nncple   ,w)uld   he  so  obvious  as   hardly  to  he  worth 
iH'tice  ;  but  Its  importance  consists  in   the  frreat  effect 
pr<.(iiice<l  by  the  accumulation  in  one  direction,  dunn- 
.Miccc.-,,ve    generations,    of  differences    absolutely    itf- 
ai.j.reciaide  hy  an  uneducated  e\  e-ditlerences  which  I 
''^r  „ne  have  vainly  attempted   to  appreciate.      Not  one 

-.1  .'lent   to    become  an   eminent   breeder.       If  irifted 
t     these  (qualities,  and    he  studies    his    «ubject  for 


,?o 


ON    THK   ORIGIN    OF   SI>KCIKS 


yars,  nrid  rlevoto  his  llfi'tinif  to  it  with  indor.i.'  iM« 
p«T  .•\-r;iiico,  1h«  will  siiccoed,  an.l  wny  make  ^rcf 
:rnpr()> cuionrs  ;  if  he  wants  ariv  of'  fhe^o  (|ualitios,  j.,. 
will  n^Mirfvlly  fail.  Few  wdiiM"  roa.lilv  holievo  in  tl'.- 
natural  <-aiiarity  aii<l  years  of"  practico'reiiuisite  to  hr- 
come  •■(.■M  ;i  skilTiil  f<iireoi!-ta!icicr. 

I  he  .,-inip  pru!cij)l(>s  are  followed  hy  horticulturists  ; 
hut  tlio  variations  are  here  often  more  al.rupt.  \r»  one 
-ui.po>es  that  our  .hniccst  ytroduitioTis  ha\eheeri  |>ro- 
dtjcod  hy  a  -iiuis^p  variation  from  tiie  a'hoiitrinal  >;tock. 
^^'e  hiivr  proofs  tliat  tliis  is  not  -o  ;?!  some  casos,  in 
vv}ii<:h  exact  records  have  heen  kefit  :  thus,  to  jriv'e  ;i 
very  fritlin-r  ii!si;uice,  the  steadily-increa.-irnr  sizo  of 
tlie  corniuon  troosi-herry  may  he  (';uoted.  We  see  id 
astoni-niiii:  in.provemeiit  iii  many  fioriNts"  fhnvcrs. 
when  'he  t!<.wers  of  the  present  (hay'are  compared  with 
driW!i,os  made  only  twenty  or  thirty  vears  airo.  Whon 
■\  race  of  [daiits  is  once  pretty  w'eil  cstahlishe.l.  the 
.iPi.d.r.rs.Ms  do  not  pick  out  the'hest  plants,  hut  merely 
an  ow-  tlM'ir  -eed-heds,  and  pull  up  the  '  ro:,Mu-^.  as 
he\  call  tlie  plants  that  deviate  from  th.^  proper 
-laiidard.  With  animals  tliis  kind  of  sel'^'-ti,,,,  is,  in 
tact,  also  followed  ;  for  hardly  any  one  is  '  careless  as 
'o  allow  his  worst  animal^  n>  hree'd. 

In  rc-ard  to  plants,  there  i>  another  means  of  ol>- 
servin:;  the  accunnilated  etlects  of  selccTion-  nam»ly. 
hy  comparin-  the  diversity  of  (lowors  in  the  difrerent 
varieties  of  the  same  &perios  in  tlie  tiower-trarden  ;  the 
diversity  of  leaves,  pods,  ..r  liihers,  or  whatever  part  is 
val.M(!,  :ii  the  kitchen-^Miden,  in  comjiarison  with 
ti,e  (lowers  of  the  same  yarieties  ;  and  the  diversity 
of  fruit  of  the  same  si)ccies  in  the  orchard,  in  com'- 
parison  with  the  leaves  ajid  Hower-  uf  the  same  -^-t 
of  varieties.  ISee  how  different  the  leaves  of  tiie 
cahha-e  are,  and  how  extremely  alike  the  flowers  ;  h..w 
unlike  the  fii.wers  of  the  heart.sease  are,  and  how  alike 
the  leaves  ;  how  much  the  fruit  of  the  ditlerent  kinds 
of  ^'ooseherries  tlitfer  in  size,  colour,  shape,  and  liain- 
ness.and  yet  the  riowers  present  very  slifrj.tditierencM^, 
It  is  not  that  the  varietjes  whicli  differ  larjfely  in  son.e 


VARIATION   L'NDKR  DOArFSTK'ATlOX 


a 


.au.  m„nt  .In  ,mt  riirer  at  all  i,.  „  ;„.r  point,  ■  thi-  ,s 
nanllv  ..v,.r.  ,„.rh;,,,s  rievor,  tlio  rase.  lUv  'au.  .,f 
c-..rn.Iat,o„  Of  .^nr.vth,  the  importance  of  u  In.!,   sLniW,! 


ii''\er  !io  (iv^'fl,, 


;Nf'.l,  will  ensun>  some  fiifr.Tencfs  ;  (,,' 


ayi  tron.rai   rn..,  I   cannot  donl.t  that   the  confin,,...! 

>».'ic.tmn  of  si,.^„t  variations,  cither  in   the   leaves    the 

n...ers    orthomnt,  .ill   pn.luce   r...  es  .l,rterin,/ f'v     ' 

each  other  chieflv  in  th<->e  rharacters 

I^  mav  he  oh,cctecl  that  the  principle  of  selection  has 

;;V7':'r"'    ";nH-tho.lical   pra.t„.etorscan.elv„u.i 

tlian  threo-.jiiarters  ot  a  centwrv  ;  it  has  cerrainlV  I m 

more  att.r,.le.l  to  of  late  years,  an,!  manv  tn^ri;      ." 
U-en  p.ihh.she.1  on  the  s„hiect  ;  an.l  the  result  has  heen 
m  a  .-orre^poiHiHiir  fh-rce,  raj,,,!  an<i   important       lit' 

'li;<"verj        I  couhl  ^,ve  sovcral   refercn.'e.  to  the  f.,11 
..•Kmnvle.!,.,nent  of  the  in.portance  of  the  principle  ;u 
v.r,...  ;.   n^^h  antM,,my.     In  ru.lean.i  harharons  pirio.is 
o.     .  u, hsh  Instory  choice  animals  wore  often  importe. 
..     a.s  were  passe<l  to  prever.t  their  export.-.lu'n  :   .1  nl 

HM.l  th-s  may  he  compared  to   the  '  ro,n,in,r '  ot  ,,i,,^^'^ 
y  •'•--> n.en.     The  principle  of  selection   1  .in^    ^ 

■x.      itTi"    '"     rr'r'''    ''"""-    encvclopa..,a. 
IjXF'lK,     rules   are  laid   down   hy  some  of  ll,e    I  omin 

h^..l  wnters.     From  passa^e^  in  (ienesis,  \ttc^ 

tliac  the  colour  of  domestic  animals  was  at  that  e-  rh 

-rw>d  .tten.ie.1  to.      .ava.es  now  sometin;!!,  rl"^, 

.'.sum.  w.l.l  cann.e  animals,  to  unprovc,  the  hreed 

'"    il'Mv.      Ihe  sava-es  m   South   Africa    nr'itch    th..,r 

t',';  u:,';;;"'of'",  '■"'■""i  "■^.■'"  "■"■■•  '-■"■''  i---.'x 

tnejr  tiMm,  of  ili.irs.      l.n,i,i.'«t.,i,o  sl,„»s  l„.»  mr.l, 


32 


ON    IHK    (K{F(;i\    (H     SI'KCIKS 


ri.-id  <|n;ilitit»s  is  so  ohNimi- 

-\i     til.'     j.n'M-ut     tiiiir.     fu.iiHMit     hic.vl.T-     trv    h- 
n.fthu.li.-.u   M.i.vtion,  with  adiMiiirt  .,!,.■(•!  in  x„.\v    to 
mak.'  a   ,„■«   strain   or  s„|,-|iro,.,l,  m,|.(m  ,ur  to  anvti.in-r 
exi^Mni:   in  th--  ro.mtry.      J{„t.  tor  '.ur  pu.pnso,  a  kind 
of   N'|...t,oi,.    vvlnrl.    may   l.o   .alK'd    lnro„.,-io,m,   and 
winr  .    ros.ilt^^  fnuo   cv-tv   or,,     trv.r.::    to   ,,(.....,.   and 
l>n'<-.l    from    the    hp-t    iiuiividiial   an,r,ial<.   il    ..ore   ini- 
p'Tlaril       Jliiis.  a  man   «|io  in!.'n<!s   k.'(  pin-  noint.Ts 
iiauna.ly  trie-  lo  trr!  a«.  i;,,.),!  do.^.  a^  ),..  ran.  ar  d  aftor- 
waMis   l.rtvd..   ir.,m   hi>  own    Ih-1  .1..-..  h.it   i,..   Lhs   no 
wi^ii  or  exportation  o/  p.-rman-ntlv  alL-rin-  t),..  l.rood 
.%evortlu.l..ss    I    raiuHd    dout-t    thai   this   i.ro.v,^     con- 
t:nu.Ml    dhnno    .H-nftirM>.    «omoI    nopnno   a,nl    modify 
i.'.v   hroo.l.  in    th..  san,..  May  as    Hakcw.-li,  (  ,dJ,ns,  vlv\ 
■y    tin.    vory    samo     {.roro.s,    only    carried     on     more 
n.othndi.-ahy,   ,\,,\    j^roatly   moditv.   even    d.inn-   thoir 
o.Mi   JiUMime.s,  tho  forms  and   .jualitios  of  tlirir  rattio 
^i<.^^  and   inxMisddo  cliaot^-  of  thi.  kin.l   could   never 
t;.'   reco-msed   UMle^s  actual   measurements  or  careful 
<w•a^'Mur^  or  ih,.  l.rrvds  in  .jue-t>un  had  heen  ma.ie  Ion- 
.-u:..,  ^^l^.•h  rn.:;hl  serve  tor  companion.      In  sumerases 
lio^ever.  unrhans:ed,  or  hut  little  chan-ed   individual 
Of   the  .same   hreed   may  he  found   in   less  <ivil,.ed   dis- 
ti-ict-s.  Where  the  hreed  has  heen  less  improved       'J  here 
i>    rea.on   lu   helieve   that    Kin^'   fharlesH   spaniel   lias 
heen  unconsciously  modified  to  a  lar^re  extent  since  the 
tune    ot     that     munar-h.        Some    hi-hlv    competent 
authorities    are  convinced    that   the   setter  is  directly 
derived  from  the  spaniel, and  has  j.rohahly  !„.,  n  .«lowlV 
altered  from  it       It  is   known  that  the  Kn-li.h  pointer 
has  h.-cn  ureatly  chaiiired  within   the  last  .entury.  and 
ni   this  case  the  chan-e  has,  it  is   helieve.i,  heen  chiefly 

etfeetedhvcr<.sscs  with  the  foT-houn(l;),ut»  hat  concern, 
us  IS,  that  the  change  has  heen  etfe.-ted  unc.msciously 
and  {rra.iuallv.  and  yet  so  etlectuallv.  that,  thouffii 
the  old  >pani.sh  pointer  certainly  came  from  .Spain  Mr 
i.orrov,  n.i.  uoi  seen,  as  i  am  informed  by  him!  an v 
native  Uof,^  in  Spain  like  our  p<dnter. 


•  ARIATION  UXDEH  DOMESTR  ATION     33 

"""Mers  ;vitli  the.f.  f.mJ    .        ^'^^-^^'r^'^  «*  carrior^  and 

thn„ih  which  tlC',;',^^  LShh":'^'  T"*^  I''*'  ^^'^- 

>n-o.listinct     ra    s^I^^^^^^^^^^^ 

^ept  by  Mr.  li.ckley^nd  mX  ^^t^^  ".V;^-;:^-  f'-'P 

marks,  "  iiave  heen  nurelv  hr^J  e^,,'  *"  •^''^-  *  ""att  re- 

a   s,i.,,„on   existing   i„    the  nihKl  of  •"'  ""' 

■''••l"ainted  with  the  sub  ec  thJ  th«  ^^'  ^  ""  '■*'  ^^^ 
them  has  deviated  iu^f™r"''"/'"''^^'^^'«'"°f 
bJood  of  Mr.  Swell  "LT  ""?'"'  ^^^^  ^''«  P"^e 
!^*'t«een  the  shVep  rn'sissfd  h '  ?l"^  ^f  '^^  differL.ce 
^o  trreat  that  thev  h^vTtht  ^  ^^  ''^^  gentlemen  is 
•'.rterer.t  varietie«-'  ^'  ^PPearance  of  bein^  quite 

of'tl!;;tSerS^r^f--«  ?  nevertothmk 
^••mestio  animals   vet  anv  nn^  «ff«Pnnff  of  their 

ful  to  them   for  'uv  sr^Zr     '"""'^^  Particularly  use- 

-ould   thuTpeneralJv  Wp'T      ^"^^  ^'^"'^•e  animals 

i"'V>rioroue«f  so  S  in   thir'""^    lf"^""^  '''^"  the 

kin.i    of    !..:"  w        •  '^'^'^  *''*"'«   ^'ould   bp  a 

fi,  ■       ••"••■"=«-. uas    opic-riion    iroin/r    nr»         w' 

fuino,  bj,  i,,^,^  |.,||^_^^^  ^_^  J  devOLri„(f  tli,.i ' 


M 


ON   THE   ORIGIN    OF   SPFX'IF^S 


old  women,  iu  times  of  dearth,  as  or  less  value  than 
tbeir  doirs. 

In  plants  the  tKime  gradual  procoHs  of  imjirovein«rril, 
throiitrh  tlio  ocrasional  preservation  of  the  Itest  indi- 
viiluals,  whether  or  not  sudiciently  distinct  to  be  ranked 
at  their  first  appearance  as  (hstincrt  varieties,  and  whethei 
or  not  two  or  more  species  or  race>  liave  become 
blended  toi.rether  hy  crossing,  may  jiiainly  l>e  recojrnised 
in  the  incre;ised  size  and  lieauty  whu  h  we  now  see  in  the 
varieties  of  the  heartsease,  rose,  pelart:oniiini,(h'ililia,  and 
otlier  planii^,  when  coni[>are(i  witli  tlie  older  varieties  or 
with  their  parent-stocks.  No  one  would  ever  expect  to 
jfet  a  first-rato  heartsease  or  dalilia  from  tlie  see<l  of  a 
wild  plant.  No  one  wouhl  expect  to  raise  a  tir:>t-rate 
nieltiiiL'  jK'ar  from  tlie  seed  of  the  wild  pear,  thoiii^h 
he  niitJ:iit  succeed  from  a  jioor  seedling  y:rowin^  wild, 
if  it  haii  come  from  a  trarilen-stock.  i'iie  pear,  thoutrh 
cultivated  in  clas>ical  times,  appears,  from  Pliny's  de- 
scripiioii,  to  have  been  a  fruit  of  very  inferior  (jiialitv. 
I  have  seen  preat  surprise  expressed  in  horticultural 
works  at  the  wonderful  skill  of  gardeners,  in  having 
produced  such  splendid  results  from  such  poor  materials; 
but  the  art,  I  cannot  douht,  lias  been  simple,  and,  aa 
far  as  the  final  result  is  concerned,  ha^  been  followed 
ahnost  unconsciously.  It  has  consisted  in  always 
cnltivatiutf  the  l)est  known  variety,  s(juin^  its  seeds, 
and,  when  a  sli;,rhtly  better  variety  has  chanced  to 
aj)pear,  selecting'  it,  and  so  onwards.  Hut  the 
irardeners  of  the  classical  period,  who  cultivated  the 
host  pear  they  could  procure,  never  thoujjht  what 
splendid  fruit  we  should  eat;  thouijh  we  owe  our 
excellent  fruit,  in  some  small  detrree,  to  tlieir  having 
naturally  chosen  and  preserved  the  best  varieties  they 
could  anywhere  find. 

A  lar^'^e  amount  of  chan/?e  iu  our  cultivated  plants, 
thus  slowly  and  unconsciously  accumulated,  exjdains, 
as  I  believe,  the  well-known  fact,  that  in  a  vast  numiier 
of  crises  we  cannot  recoirnise,  and  therefore  do  not 
knov\,  Uie  wild  parent-stocks  of  the  plants  wiiicii  have 
be«i?u   longest   cultivated   in   our    flower    and    kitcheo 


as 
,1 


VAKIATION  INDKR  DO.MKSTirATIOX     35 

^'aniens.      If   it   has    take,,  centuries  or  tlu.usands  of 
>.'ar>to   improver   modify  m.wt   of  our  plants  u,.  to 
tl..'.r  pr.MM,t   stan.iar.l  0/   u.Wulnes.  to   Lu,  „,  '  ...^ 
un.h.rsunul  now  .t  1.   that  neither  Australia,  the  Cape 
«'f  <-"»;l  J  Ope,  nor  any  other  ret,non  inhai.Ue.i  hv  ..uitc- 
un.Mv.hse.1  man,  has  artonied    us  a  sintrh-  plant  «rth 
'•ulture       It   ,s    not    that   these    oo.nK.es.L     i.  h 
^p.-uesdonot   hy  a   Mran^M,  ehan.-e  po^e^s  the  ahor 
.ma    stocks  ot  any  nsefwl   plants,  hut   that   the  native 
i-mts  have  not  hee:.   improve,!    hy  rontinue<l  sel  vtVon 
"i.   ^o  a   -lan.iard   o.    pertertion   comparahle  u  ith   th" 
.■iv.-.i  to  the  plants  u.  <-ountnes  anceutiv  civilised       ' 

In  reirard  to  the  do.nestic  anunalskepi  hv  uncivilised 
-;-■".,  .t    should    not    he  overlookci    that   they   al  m  . 
aluayshave    to  struirt:le   for  their  own    food.' at    "a, 
|:inn.^   cerum,    seasons.     And    in   two  count  ies     e'v 
'i-'Vn.ntly    circumstanced,    individuals    of    the    s^u.  e 

?;;;■'.;"     *''"'11    f'-^^'-'-^-    •'■'•-^"^     constitution^   .r 
>  ru.-ture  would  oflen  succee.i  hetter  in  the  one  countrv 
thru,  in  the  other;  and    thus  hy  a  process  of  '  Hat,    .^i 
M-le.-t,on,   as  will    her.vifter   he' more   fully   exp  ai  led 
t->suh-hreeds  mi.dit  he  forme.l.     This,  perhap  ,  p        '- 
evpla.n.    what    has   heen    remarket!   hy  Lnie'aL  lori 
iK^mely    that  the  varieties  ke,,t  hy  sava^a,s  have  m"  r^ 
ot  the  character  of  species  than   the  varieties   kei^     ,1 
civilised  countries.  '      '" 

« >'i   the  view  here   t^iven   of    the  all-important  part 
winch  .election  hy  man  has  played,  it  heco  ues  It  . mce 
ohvious  how  ,t  ,s  that  our  domestic  races  shuv^lda^ 
t.on  m  their  structure  or  in  their  hahits  to  mans     S 
.>r  fancies.      U  e  can    1    think,  further   understand      le 
.*re.|uently   ahnormal  character  of  our  domesti     ra<'e 
■^'"i  likewise  their  differences  hein-^  so  .^reat  i.i  exte  rai 
'  haracters  and  relatively  80  «]i,.ht  in  internal  ,'irts  or 
orjrans.     Man  can   hardly  select,  or  only    w    I   ";;,,' 
d.lhculty.  any  deviation  of  structure  ex.-eptin^  such  Is 
u^  externally   vu^ihle  ;  and   indeed   he  rarlly  l^r!^^ 
-^^a.  ;^  iiiternai.     He  can  never  act  hy  selection    ex 

^me  =,l,ght  degree  by  nature.     No  man  would  ever  tn- 


96 


ON   THE   ORIGIN    OF   Sl'fcXJES 


h 


to    make  a  lanfiil,    till   he  saw  a  pij,,.,,,,   with    i    tail 
developed  iii  >,„ne  sli-ht  df^rreo  in  an  -inusual  manner 
or  a  pout.'r  till  ho  saw  a  pi-eon  with  a  rrop  of  som.-uhit 
unusual  s]/.e  ;  and   the   more  ahnorinal  or  unuMial  any 
rharacter  was  when  it  first  appeared,  the  more  lik.-lv  i't 
would   ho  to  catch   hi.satt.-ntion.      Hut  to  une  su,h'a-> 
ivvpn'-siuri  a.^  tryiii;,'   to   make  a   fantail,  is  i   )iave  -lo 
d')u,.t,  u,  most  eases,  utterly  incorrect.      Ihe  man  ^^  ho 
first  Mi.Tt.Ml  a  pi-eon  with  a  si■^^htlv  lar-er  tail,  ne\->r 
drear  ed   what  the   descendants  of  that   pi-eon    woiild 
become   through    lontr-continued,   partly    unconscio,i.s 
and   part  y  n...tho,li,aI   .election.      I'erhap.  the  parent 
l.r.l  of  all  tanUils  had  only  Jo.jrteen  t^iil-feathers  some- 
what expanded,  like  the  present  Java  fant^iU,  or  like 
individuals  of  other  and  distinct  breeds,  in   which  as 
many  as  seventeen  tail-feathers    have    been   counted' 
I  eriiaps  the  first  pouter-pi <reon  did  not  inflate  its  croo 
much  more  than  the  turbit  now  does  the  upp.-r  part  of 
.te  *sophairus,-a  hahii  whicli    is  disre^rarded    by  all 
taiT.;crs   as  it  is  not  one  of  the  point*  of  the  breed' 

^or  let  It  be  thoufrht  that  some  preat  deviation  of 
structure  would  be  necessary  to  catch  the  fancier's  eve- 
he  perceives  extremely  small  differences,  and  it  is  in 
human  nature  to  value  any  novelty,  however  sli-ht  iu 
one  8  own  possession.  Nor  must  the  value  which  would 
formerly  be  set  on  any  sli-ht  difTerences  in  the  indi- 
viduals of  the  same  species,  be  judged  of  by  the  value 
whi.h  wouhl  now  be  set  on  them,  after  several  breeds 
have  once  fairly  been  established.  Many  slight  ditler- 
euces  miKnt,and  indeed  do  mow,  arise  amonirst  pi>eon« 
which  are  rejected  as  faults  or  deviations  from  the 
standard  of  perfection  of  each  breed,  'i'he  common 
^oose  has  not  KJven  rise  to  any  marked  varieties  ; 
hence  the  1  hoiilouse  and  the  common  breed,  which 
differ  onlv  m  colour,  that  most  HeetinK  of  characters, 
have  lately  been  exhibited  as  distinct  at  our  poultry- 
shows.  *^  •' 

I  think  these  views  further  exnlain  what  has  -"-^-. 
times  i,een  not.ced-namely,  that  we  know  notliiiu' 
about   the  orif-iu  or  history  of  any  of  our  domestic 


7^  ^.r^^^^^^^«I^^*??] 


VARIATION  UxVDER  DOMESTICATION      ,37 

breed..      lUa,   in    fact,  a    bree<l,   like   a    ,J,.dert   of  a 

lar..r„ape,  can    J.ar.ily  I..   „aid    to  have  ha.l  a  .iefin  te 

.-  nr.     A  man  ,   esorves  .nd  bre<  ,1s  from  an  ir.di'n     d 

«  :1.  .ome  si-,. hi  deviation  of  structure,  or  Uke     n     e 

.nretuan  usual  ,n   mat.lm,,.  Ms  Lost  anirnal'ami  thu" 

-proves    u.e:n,  and    the   irnprovod   individual,  so.h 

THMd     n   the  nnmed.ate  nei^^hhourhood.      J{ut  al   vet 

•-.;>  -.11  hardly  have  a  dist.n.t  nan.e,  and  from^,^^^^ 

on  y  >h,.ht Iv  valued,  their  history  will  he  dJe^Zl 

I>-..ewM,  they  ndi  spread  m„re  widcdv,  and  will  -et 
e<  ..nnsed  a.  ».>n,ethin..  distinct  and  valuable,  and  vT-l 
.en  i.rr.hahly  nrst  receive  a  provincial  ,.an.e.  In  sen. 
n-.il.'-.d  countnos,  with  hftle  free  connn.ni.-^tion  1 1. 
^pre..,l,n^  and  knowled,.- of  any  new  .ul,  hreedJil  . 
«  ..h>.  process  A.  soon  a.  the  poinUs  of  val'e  o  ^ 
:..-  suh-hre.d  are  once  fully  acknowled^^ed.  the  or  n 

■       i      *®"'  i  ~   '"'''-^PS    more    at    one   period    than    at 
a.-other,  as  the  Ireed  riMen  or  falls  in  fashion.       ;'   ar! 
n...re  in  one  district  than  in  another,  accord  ,..i  t^^ 
.  .teofc.v.l,s.Umn    of  the  inhahitan'ts- .lo.ly  to  add 
-  the  character.sfc   features  of  the  breed,  whate^'er 
-y  may  be      But  the  chance  will  he  inrin  lel    hh  nl 
..f  any  record    havmg  been    preserved   of  such  Xw 
>aryin^,  and  insensible  changes  ' 

I  n.ust  now  say  a  few  words  on  the  circu -..stances 
favourable  or  the  reve^.e.  to  man's  power  ot      locUon 
A  )u,h  de.^ree  of  variability  is  obviously  favourable^ 
fr.  ely  p,v,ng   the  materials  for  selection  to  work  on 
uot   that   mere  individual  differences   are    not   amn^' 
-mcient,  with  extreme  care,  to  allow  of  the°u  cur^uk 
^on  of  a  lai-Ke  amount  of  modification  in  a  n',^? an" 
•lesired  d,rectu,n.      Hut  as  variation,  manifestl  "If^^ 
u    p  easing  to  man  appear  only  occasionally,  the  chance 
-f  their  appearance  will  be  much  increa.sed  by  a    ar^e 
numher   of  individuals   bein^  kept  ;    and    lice  "hi! 
•■•:.-  ^  !^«  o^ti^ie  hisfhest  in.j,o-tance  to  succe«i^      On 
-  principle  Marshall  ha.s  remarked,  with  res.Lt    0 
^.-  =heep  of  part«  of  Yorkshire,  th.t     U  they  .^eirerau' 


ON   THK    OR[(;iN    OF   SPKC  IKS 


!'»'loiiir    to    jHior    [)»•(. pic,  ami   .iro  nio-Mv  in  uvuill  /o/*, 
thfv    ii.'ver    r-;iii    })«    im_irov»><|.'      On    tlio  otlicp    }|!iTid,' 
niir-iTvnuMi,    fnun    raivirnr    l.-irtrn    sfo.  k->   of  tli»>   vame 
pl.iiits.are  yenpraily  far  morp  siiccp^^ful  Hiari  aiiKit.Mirs 
in  trettiinf  now  and  valnal.U?  varieties.       I  lie  ke<>[»ini,'  of 
a    I.ir;:(>    iiurii'MT   of  itii|i\  idiials    of  a   -Ji-ecieH    lu    aiir 
coiiiitrv    re(|iiire<j    t}iat    tlie    specie^j   sliould    Ko    plared 
under  favonraMo  coiiditions  <»f  life,  ho  is  to  hrcM  freelv 
in  that  cotmtry.      ^\  lien   th*>  individua!-'  of  any  species 
are  scaiitv.  ;ill   tlie   individuaU.  wdatever  tlieir  quality 
niav  he,    will    .generally  ho  allnvred   to   hreed,  and   this 
will    etfecttrilly   prevetit    sel.ction.      Wnl   prol.al.ly   Mie 
most    ini|.<>rtant    pcint   of   ail    is,    that    tile  animal  or 
plant   should    Im.  so   lii;.r|,ly  ;,spf,jl   to  man,  or  so  miirh 
valued  hy  him,  that  the  closest  attention  should  he  paid 
to    even    the    sliirjitest    deviation    in    the    (jualities    or 
structure  of  each  individual,      rnless  such  attention  he 
paid    tu'thin^'   can    t.e    etlected.      I  liave  seen  it  uT-ivelf 
rerTiarked,    that    it  was   mo>t    fortunate   that  the">traw- 
herry    hej.'-.-in   to   varv    just   wlien    trardeners    h««:ran   to 
attend  closely  trj  this   plant.      No  douht  the  strawherrv 
had  ainays  varied  -ince  it  was  cultivated,  hut  the  shVht 
varieties    had    lieen    tiet^Ierted.      As  soon,  however,   as 
^rirdeners   pi-kcl   ..ut   individual    plants    with    sliurhtly 
I.'irjrer.   earlier,    or    Letter    fruit,  and    raised    seedliriir's 
from  ther>'    and  aj-ain  picked  out  tlio  hest  seedliiiirs  and 
t  red  t'rom    them,  then,  tl, ere  appeared  (aided   hy   so-ne 
crossiii^r  ;vit)i    distinct  species;    those  rjianv   admirahle 
varieties    of   tlie    strawherry  wh'ch    have   heen    nii^.'d 
duriiiir  die  !'i>t  thirty  or  forty  years. 

In  tiic  -^i-se  of  animals  vvith  separ.te  sexes,  facil'ty  in 
pre-iMai- ir  cnx-os  is  an  import;int  element  of  success 
Ml  the  f.M-inatio'i  nf  new  race-,— at  lea>t,  in  a  country 
which  ix  already  stocked  with  other  race,«.  In  this 
resftect  enclosure  of  the  land  [>iays  a  part  Wandering 
■Miva:res  or  the  inhahitant.s  of  open  plains  rarely  possesa 
more  tlian  one  breed  of  the  same  species,  ri-reoiis  can  be 
m.iteil  for  lite,  and  this  iit  a  irroat  ccnveriience.  t.o  th« 
fancier,  for  tiius  many  races  may  he  kept  true,  thouiih 
miKjfled  in    the  same  aviary  ;    and   this  circum.stance 


VAIUATION  I'NDKR  DOMKNTICATION      39 

must  h.ivo  larn-plv  favoured  tho  impnivernent  and 
foniMtiun  of  new  l.rep<ls.  l*ii:<'oiis,  I  may  a<i«l.  cin  l<« 
pr«.|.a(.Mt«'il  in  trn-at  miml.ors  riiKi  at  a  vrry  quit  k  rate, 
and  iiifcridr  hinisniayhe  freely  n>iprted,  as  when  killed 
thev  nerve  for  tiKMJ.  On  the  other  hand,  cats,  from 
their  nocturnal  ranildijit'  hahits,  cannot  he  matched, 
■itkI,  a]thou{:h  so  much  vahied  hv«(.men  and  children, 
we  hardly  ever  nee  a  diMtin<t' hreed  kept  up;  mich 
breeds  as  we  do  sonietirneM  see  are  almost  always  im- 
ported from  some  other  country,  otlen  from  is'laiulv 
Althoiii:h  I  do  not  douht  that  s<.me  domestic  animals 
vary  less  than  others,  yet  tho  rarity  or  ahsence  of 
distinct  breeds  of  tlie  cat  t>'e  donkey,  peacock,  iroose, 
etc. ,  may  he  attrihuted  in  iMain  part  to  selection  not 
haviii,^  heeii  hrouir'.t  into  play  :  in  cats,  from  the  dith- 
cilfy  in  pairing  tliem  ;  in  (h.nkevM,  from  only  a  few 
heiii!;  kept  hy  poor  people,  and  lit'tle  attention 'paid  lo 
their  hre«'diiijr;  in  t>eacockH,  from  not  heiiitr  very 
easily  reared  and  a  lar^e  stock  not  ke|.t  ;  in  fcree<e. 
from  hein^r  valualde  only  for  two  purpoM's,  food  and' 
feathers,  and  more  espeeiallv  from  no  pleasure  havin^r 
l-een  felt  in  the  display  of  distinct  hreeds. 

losiim  lip  on  tho  or!::in  of  our  l>..mestic  Haces  of 
animals  and  plants.  I  helieve  that  tiio  conditions  of 
life,  frr)m  their  action  on  the  repr()ducti\o  sv^tem,  are 
so  tar  of  tlie  hii^liest  importance  as  ca.isin::  variahilil y. 
!  'lo  not  helievp  that  variability  is  an  inherent  and 
ii^-^'cssary  contin;(en<"y,  uiuler  al'l  circumstances,  with 
il!  ortranio  heinLrs.as  ^jme  authors  have  thoii-ht.  I  he 
•••fects  of  variability  are  uuuiified  hy  various  de:rrees  .,f 
nihcritance  and  of  reversion.  Variability  is  450%. •rued 
by  many  unknown  laws,  more  especially  by  tliat  ot  cor- 
relilion  of  ;:rowth.  Something--  may  be  attributed  to 
'h>'  direct  action  of  tlie  conditions  of  life.  Sr.metliinw 
'ti  1st  1^  attrihuted  to  u.<!e  and  disuse.  The  final  re-ult 
in  thus  rendered  infinitely  complex.  In  some  r-.^M,  I 
do  n(.t  doubt  that  the  i..tercrossine  of  Hpecien,  ahori^ria. 
■ -ly -listiiict,  li.t.-,  piayeu  an  important  part  ui  the  onirm 
"f  our  domestic  productions.  U  lion  in  ariv  country 
several  doinetitic  breeds    hare    once  been  ertablished, 


40 


ON   THK   omCIN    OF   SPKC'Ih:S 


ll^ 


tlieir  occaninnal  iiiterrros«iruf,  witli  tlif»  aid  of  m-lertion, 
li.is,  no  (loijlit,  lartroly  ai'ini  in  tJie  fi»riii;iti()ii  of  new 
Kiih-lireeds  ;  but  tlio  iiiiinirtanco  of  ll<n  rrosxintf  of 
varieties  has,  I  believe,  been  jrre.itly  ex.-iirtrerated,  Itotli 
in  retrard  to  aiiinuils  and  to  tlio<ie  jil.ants  wliidi  are 
|iroi>i::iited  by  need.  In  plants  wbicli  are  temporarily 
prnpau'stted  by  cuttintrs,  buds,  etc. ,  tlie  imrmrtance  of 
tin'  iro-.sin(r  botli  of  di-itinct  sperien  and  or  varieties  !► 
immense;  for  tlie  rultivntor  liero  quitu  di-jreirardH  ibo 
extreme  variability  both  of  liyltrids  and  nion>i:rels,  and 
tbe  frerjiient  sterility  of  bvbnds  ;  but  tbe  <  ase»  of 
plants  not  projia^Mteil  by  seed  are  of  little  importanc. 
tf  us,  for  their  endurance  Ik  only  temporary.  Over  all 
the^e  causes  of  (  baiitre  I  nm  eonvinied  that  tbe 
a<  i-unnilative  action  of  Selection,  wbether  apjdieii 
m.  tlioflically  and  more  quickly,  or  uiiconscitmsly  and 
mure  slowly,  but  more  efficiently,  ia  by  far  tbt*  prt- 
doininant  I'owor. 


CHAl'lKR    II 


VAUfAriuV     INDKH     NATIKK 

'    '''''"i'y-.J'""*i'l""!'l'tr<r-iM-     I...ulitful,,HH-le.-  WMrrun^n. 
-'u:h  .li.I,..s.-.l    ai.a  ,„.imi.,„  „„.,.„.,   var>  ,Mo»t-    >i..  •  i.,  „f  ih; 

vwru-iicg   ir,   l,Wn«  very  d,.«Wy.  hut   uue-iualiy,  f.iuU.l    t..  „^h 
•UitT,  and  in  iiav.i,^'  rtslri..i,  ;  i.^.^j,-,*. 

Hkm)hk  aj^plyini;  li„,  pridciplos  arrive,!   at   iii   ine  Um 
.  naptor  to  or^.iiih   l.eiiiK>  ii)  a  stile  of  naUiv",  we  n,  ,.t 
i.ii.-M\  ,lisrii>~   vvlu-ther  tlu-so  lattt-r  ar.,  sul-.f.-t  to  ,iii\ 
Narial.oii.      "J  o  treat  tl.i^  sul.ject  at  all  pru|M'riy,  a  Urn. 
<  ..■'  n^r,H.  of  dry    farts   shoiil.l    bo  u^^vu  ;   Init   tlu-.e    I 
'•fi.iii   ri-M,rve   fur   my    future   work.      \(,r  shall  I  here 
(liM-uss  the  various  defmitioiis  whicli  have  he.ii  i,M\eu  of 
t,iL.  tonn  '  species.'    No  ojie  delinition  has  iis  yet  Kati.stied 
ah    ualiiranfs  ;    yot   every   natiiiaiist    kiioxvs    vaiznelv 
v^  hat  he  meai..,  when  he  sj.eaks  of  a  soccu-^.     ( Joiier  .11  v 
tuu  term  includes  the   unknown   elerV.ent  of  a  di.sUnct 
a,t  of  creation.     The  term  '  vanotv  '  is  almust  equally 
MthcuJt  to  define;  but  here  community  of  de^.ent  in 
almost  universally   implied,  thou-h    it  can   rarelv    he 
!  rovo.l.     \\  e  have  also  what  are  called  mon>trnsui.-s 
I'.t  t.iey  ffraduate  into   varieties.      By  a  monstrosity  1 
iH-Mime   IS     meant    some    considerable    deviation    of 
-uu.ture  in  one  part,  either  injurious  to  or  not  u.-4ofui 
.0   llie  species,  and   not  generally   prop.i^raie.l.      .Some 
a  ithors  use  the  term  'variation'  in  a  te.hiji.  a] 
n,;il\'ino-  a   n!odiH;-.-t!.--r-. 

ci-!.ditions  of  life;  and 

Hupposed  not  to  be  inherited:  but  wh 


sense,  as 

liuc    lo    tijc    piiv>.cai 

variations'   in   this  sense  are 

o  t'-au  r«a\  that  tlu 


4] 


t2 


ON   THK    ORICJIN    OF   SPK(  lES 


l! 


(iwarfrd  conflitio'i  of  slielN  in  the  }ira<'ki>h  waters  of 
tiie  I'.i'tic,  or  (iuvirfed  [li.iiils  on  Alpiri"  •iiirruniL«,  or 
the  thirkpr  fur  of  an  animal  t'roin  far  tiorthwanls,  would 
not  in  soMio  rases  he  inheritoil  for  at  least  some  few 
ireu'Tations  r  and  in  this  case  I  tiresunie  tliat  the  form 
would  he  called  a  variety. 

Airain,  we  have  many  slit'^ht  dilTerenoes  which  may 
he  called  mdivirlijal  differences,  sin-h  as  ara  known 
fre<]iiently  to  ajiiicir  in  the  olf-prinir  from  the 
s;inio  parents,  or  wliich  may  he  presumed  to  have  thus 
arisen,  from  hein^  freciiiently  ohserved  in  the  indivi- 
duals of  the  same  species  inhahitin»f  the  same  confined 
locality.  N'o  one  supposes  that  all  the  individuals 
of  tlie  same  species  are  cast  in  the  very  same  mould. 
These  individual  differences  are  hifrhly  important  for 
us,  as  they  afford  materials  for  natural  selection  to 
accumulate,  in  the  same  manner  as  man  can  accumi- 
lafe  in  any  yiven  direction  iiulividual  differences  in  his 
dc)mestic^ateti  productions.  'Hiese  individual  differences 
?onerally  affect  what  naturalists  consider  unimportant 
[wirta  ;  hut  I  could  sliow  hy  a  lonfj  cat.iloirue  of  facts, 
that  parts  which  must  Vie  called  importdit,  whether 
viewed  under  a  physiolojrical  or  dassific-atory  point  of 
view,  sometimes  vary  in  the  individuals  of  the  same 
specii's.  I  ain  convinced  that  the  most  experienced 
natu'-alist  would  Ini  surprise<l  at  the  numhcr  of  the  cases 
of  variahilit>  even  in  importmt  parts  of  structure,  which 
ho  coulil  collect  on  ^ood  authority,  as  I  iiave  collected!, 
diirin:;  a  course  of  ye^'irs.  It  should  he  rememheied 
Uia*-  systematisfs  are  far  from  pleased  at  finding'  varia- 
bility in  important  characters,  and  tliat  there  are  not 
many  men  who  will  la!H)rii  isly  examine  internal  and 
iniporlHiit  or^rans,  and  compare  them  in  many  speci- 
mens of  the  ivjime  specip«.  I  sliould  never  hav»i  exfH^cfeil 
that  th«  hranchintr  of  the  main  nerves  dose  to  the  a^reat 
central  irauirlion  of  an  iu^ect  would  have  hecn  variahle 
in  the  same  species  ;  I  should  have  expected  that 
chan^^es  of  tins  nature  couid  have  been  effected  only 
by  slow  dci^r'^es  :  yet  (juite  recently  Mr.  Luhhock  has 
shown  a  detfree  of   varialiility  in    these   main    nerve* 


VARIATION   UKDER   xNATIJRE  43 

hi  CocciiP,  winch  may  ainjost  be  compared  to  the 
irrPiruI.-ir  branrhino:  of  the  stem  of  a  tree.  Tliis 
phil.mopbical  naturalist,  !  may  add,  has  also  quite 
recetitly  rthnwri  that  tlie  muse  Ips  in  the  larvte  of  cert^iin 
in.se.f-i  are  very  far  from  uniform.  Authors  sometimes 
artrup  in  a  rir.le  when  they  stMe  that  imi>ort;int  ortjans 
never  vary  :  for  these  same  authors  practically  rank 
that  character  as  important  (a--  some  few  naturalists 
have  hone-tly  confessed)  which  does  not  vary  ;  and, 
iiiider  this  point  of  view,  no  instance  of  an  important 
part  varyintr  will  ever  be  found  :  but  under  any  other 
point  of  view  many  instances  assuredly  can  l»e  tr'iven. 

There  is  one  point  connected  with  individual  differ- 
ences which  seems  to  me  extremely  perplexinjf :  I  refer 
to   those  e^enera    which    have   sometimes    been    called 
'prolean'    or    'polymorphic,'    in    which    the    specie* 
present  an  inorditiate  amount  of  variation  ;  and  hardly 
two    naturalists    can    a^ree    which    forms    to    rank    as 
species   and    which    as    varieties.       W'e    may    instance 
Kubus,  Kosa,  and   Ilieracium  amonp^st  plants,  several 
penera  of  insects,   and   several  jrenera  of  llrachiopod 
shells.       In   most    polymorj>hic    (genera    some   of   the 
species  have  tiied    and    definite    characters.       (Jencra 
which  are  [»olymorphic  in  one  country  seem  to  be,  with 
some  few  exceptions,  noivmorphic  in  other  countries, 
and  likewise,  judjrintr  from  Hraciiiopod  shells,  at  former 
perio<ls  of  time.      These    fa.-ts    seem  to  be  very  per- 
plexinif,  for  they  seem  to  show  that  this  kind  of  vari*. 
Julity  ifl  kndej.endent  of  the  conditions  of  life.      I  ..m 
inclined  to  suspect  that  we  see  in  these  polvmorphic 
j:enera  variations  in  points  of  stru.ture  whi.h  are  of  no 
service  or  disservice   to  the   species,  an.l    which  con- 
W'l"«""tly     ha%e    not    been    seized    on    and  rendered 
dehmte    by    natural    ^election,   an    hercifter    will    he 
explaiued. 

Hiose  forms  which  possess  in  some  considerable 
desrreo  the  character  of  species,  hut  w.iicb  ar^  qq 
cirw-eiv  similar  to  some  other  forms,  or  are  so  closely 
hnked  to  them  by  Intermediate  tfradations,  that 
oaturaDsts  do  not  like  to  rank  them  as  distinct  specieii, 


44 


ON  THE  ORIGIN    OF  SPECIES 


'M 


arp  in  several  respects  the  most  important  tV)r  uii.  We 
have  every  rcison  to  believe  tliat  ma/iv  of  thesf 
ddiilaful  and  closely-allicii  forms  have  jierniaripntly 
retiiried  their  characters  iu  their  own  country  for  a 
luiiiT  tirrifc)  ;  for  as  InufX,  as  far  as  we  know,  as  liave 
f<-()0(i  and  true  species.  I'ractirally,  when  a  naturaiisi 
can  iiuito  two  forms  toffeLher  hy  others  havintr  inter- 
mediate characters,  he  treats  the  one  as  a  variety  of 
the  other,  ranking?  the  most  common,  but  sometim*  t 
the  one  fir-^t  dn-crihed,  as  liie  specie^,  and  llie  other  as 
♦}i*'  variety.  But  cases  of  creat  difficult;,,  which  1  will 
not  here  enumerate,  som -times  occur  iu  dt'cidiu^' 
wliether  or  not  to  rank  one  form  as  a  variety  of 
another,  even  when  they  are  closeh  conmclcd  by 
■  nteriiiediate  links;  nor  will  the  commonl} -.i^samed 
hybrid  nature  of  the  intermediate  links  alwavs  reuiovt 
the  difficult/.  In  very  niariy  ca-cs,  however,  one  form 
in  ranked  as  a  variety  of  mother,  not  because  the 
intermediate  link.s  have  actually  been  found,  hut 
i.ecause  analoiry  leada  the  observer  to  supjiose  either 
that  they  do  now  somewhere  exist,  or  may  formerly 
h:.ve  existed  ;  and  here  a  wide  door  for  the  entry  of 
doubt  and  conjecture  is  opened. 

Hence,  in  determining  whetlier  a  form  should  be 
ranked  as  a  species  or  a  variety,  the  opinion  of  natural- 
isLs  having  sound  judg-ment  and  wide  experience  seems 
thi'  only  guide  to  follow.  We  must,  however,  in  many 
ca-e«,  decide  by  a  majority  of  naturalists,  for  few  well- 
marked  and  well-known  varieliejj  can  be  named  which 
have  not  been  ranked  as  species  by  at  least  ome  com- 
p.  tt'Mt  judfres, 

■J'hat  varieties  of  this  doubtful  nature  arc  far  from 
uncommon  cannot  be  disputed.  Compare  tlie  several 
floras  of  Great  Britain,  of  France,  or  of  the  United 
i>t.ites,  drawn  up  by  different  botanists,  and  see  what 
a  surprising  number  of  forms  have  been  ranked  by  one 
botanist   as    good    species,    and    by    another    as    mere 

:_i: —       ^f  _    II    f>    ii-_*  .,  -.    i  -    _u-_-   r  i!  _      -    i         i 

ra;ic.:t--.       .rii.   a.  \  ,    TraL.-i;;;,  la    ~  livTli  i    lie  L.n.'iCr  UCCp 

obligation  for  assistince  of  all  kinds,  has  marked  for 
me  182  Briti^V  plnnls,  which  *re  generally  considered 


VARIATION  UNDER   NATURE 


45 


US   varieties,   but   which    have    all     hoeii     ranked     by 
botinisU  as  specit-.s  ;  and   iu   makiuu--  this  list   he   haa 
■Miiitted  many  tridiufr  varieties,  but  which  U'jverth.'I.-^s 
h^ive  been  ranked  by  some  botanists  as  species,  ami   he 
iias  entirely  omitted  several  hiifhly  polymorphic  p-c:i.Ta. 
'  n-Urr  g-enera,  includinor  the  most  polvmorphic  f..;  ins 
Mr.    lial.intrton   gives  251    species,    wlierea.s  Mr.    J5en' 
•ham   gives  only    112,-8  difference  of  l.'W   doubtful 
forms  I     Amongst  animals  which  unite  for  each  birth, 
and    which    are    highly    locomotive,    doubtful    forms,' 
ranked  by  one  zoologist  as  a  species  and  by  another  as 
a  variety,  can  rarely  be  found  within  the  same  country, 
but   are  common  in    separated  areas.      How  many  of 
those  birds  and  insects  in  North  America  and  Europe 
which  ditfer  very  slightly  from  each  other,  have  lieeu 
ranked  by  one  eminent  naturalist  as  undoubted  species, 
and  by  another  as  varieties,  or,  as  they  are  often  called' 
asgeograpliical  races  !  Manyyear8a{.'o,when  comparing* 
and  seemg  others  compare,  the  birds  from  the  separate 
Islands  of  the  Galapagos  Archipelago,  both  one  with 
another,  and  with  those  from  the  American  mainland, 
I  was  much  struck    how  entirely  vague  and  arbitrary 
18  the  di.stinction  between  species  and  varieties.     On 
the  islets  of  the  little  Madeira  group  there  are  many 
insects  which  are  characteriged  as  varieties  in  Mr.  ^V^)l- 
laston's  admirable  work,  but  which  it  cannot  be  doubted 
would  be  ranked  as  distinct  species  by  many  entomo- 
loirists.     Even  Ireland  has  a  few  animals,  now  generally 
regarded   as   varieties,    but   which   have   been   ranked 
IS  sj)ecie8  by  some  zoologists.    Several  most  e.vt)erienced 
ornithologists  consider  our  Hriiish  red  jfrouse  as  only  a 
^trontriy-marked  race  of  a  Norwegian  species,  where;i8 
the  greater   number  rank  it  as  an   undoubted  species 
I>ecuiiar  to  Cireat  BriUiin.     A  wide  distance  between 
the  homes  ©f  two  doubtful  forms  leads  many  naturalists 
to  rank  both  as  distinct  species  ;  but  what  distance,  it  has 
been  well  asked,  will  sutlice.^  if  that  between  America 
;;;'i    nurope  ih  Hinpi,.,  will  that  between  the  Continent 
uid  the  .A/ores,  or  Madeira,  or  the  (anaries.  or  Ireland 
«  sufficient  ?     It  must  be  admitted   that  many  forms' 


46 


ON   THE   ORIGIN    OK  SI'ECIF:S 


eonsidered  by  bifjhly-irompetent  jiidfrf^'  as  varieties,  have 
so  perfectly  tbe  character  uf  species  that  they  are  ranked 
by  otlier  hitrhly-coinpetent  jud^^es  as  good  and  true 
species.  But  to  discuss  whether  they  are  rightly  called 
species  or  varieties,  before  any  detiiiition  of  tiiese  terms 
h;is  been  peiierally  accepted,  is  vainly  to  beat  tiie  air. 

Many  of  the  cases  of  stronfrly-niarke<l  varieties  or 
doubtful  species  well  deserve  consideration  ;  for  several 
iutercstinj^  lines  of  arffunient,  from  treotrraphical  dis- 
tribution, aiialofjical  \ariation,  hybridism,  etc.,  have 
been  l)routrbt  to  Itear  on  the  attempt  todetermine  their 
rank.  1  will  here  jfive  only  a  single  instance,— the 
well-known  one  of  the  primrose  and  cowslip,  or 
I'rimula  viiliraris  and  veris.  These  j)lanls  differ  con- 
sideral)ly  in  appearance;  they  have  a  diJerent  flavour, 
and  emit  a  dirferent  odour  ;  they  llower  at  slightly 
dirteient  periods  ;  they  grow  in  somewhat  different 
stiitions  ;  tiiey  ascend  mountains  to  different  heights  ; 
they  liave  different  geographical  ranges  ;  atid  lastly, 
accorduig  to  very  numerous  experiments  made  durifig 
several  years  by  that  most  careful  observer  (iartner, 
they  can  bo  crossed  ofily  with  much  difhculty.  We 
could  hardly  wish  for  better  evidence  of  the  two  forms 
being  specifically  distinct.  On  the  other  hand,  they 
are  united  by  many  intermeciiate  links,  and  it  is 
very  doubtful  whetlier  these  links  are  hybrids  ;  and 
there  is,  as  it  seems  to  me,  an  overwhelming  afuount  of 
exp«'riinental  evidence,  showing  that  they  descend 
from  common  jtarents,  and  consetjuenily  must  be 
ranked  as  varieties. 

(lose  investigation,  in  most  cases,  will  bring  natural- 
ists to  an  agreement  liow  t  >  rank  douhtiul  forms.  Yet 
it  must  be  confessed  tha,  it  is  in  the  best- known 
countries  that  we  find  the  gre;itest  number  of  forms  of 
doubtful  value.  1  ha\e  been  struck  witli  tlie  fact,  tliat 
if  any  animal  or  plant  in  a  state  of  nature  be  highly 
useful  to  man.  or  from  any  cause  closely  attract  his 
attention,  varieties  of  it  will  alsiiOst  universally  1>6 
found  recorded.  These  varieties,  moreover,  will  be 
often  ranked  by  some  authors  as  spe<Mos.      IawU.  at  th« 


VARIATION   UNDER    NATURE 


47 


eommon  oak,  how  closely  it  has  been  studied  ;  yet  a 
(iernian  autlior  makes  more  tliaii  a  dozen  8j)e«-'ies  out  of 
forms,  whic-li  are  very  generally  considered  as  varieties  ; 
Hud  in  this  country  the  highest  hotanical  autliorities 
and  practical  men  can  be  (juoted  to  show  that  the 
he>sile  and  pedunculated  oaks  are  either  good  and 
di•^tiIlct  species  or  mere  varieties. 

W  hen  a  younu'  naturalist  commences  the  study  of 
a  trntup  of  orffanisms  quite  unknown  to  him,  he  is  at 
first  much   perplexed  to  determine  what  diriVrences  to 
consider   as    specific,    and    what    as    varieties  ;    for    he 
kn(»rts  notliintf  of  the  atnimnt  and  kind  of  variation   to 
which  the  yroup   is  subject;  and  this  shciws,  at  least, 
!iow  very  t^eneraHy  there  is  some  \ariation.      Hut  il  he 
(•online  his  attention  t<»  one   ■'  v.-.s  within  one  countrv, 
be  will  soon  make  up  his  mnid  how  to  rank  m<»«.t  of 
the  doulitful  forms.       His  jfeneral  tendency  will  le  to 
riKike  many  species,  for  he  will  become  improved,  just 
like  the  pijreon   or   poultry   fancier  before  alluded  to, 
^^ilh   tbe  amount  of  ditlerence  in  the  forms  which   he 
!s   continually    studyintr  ;    and    he    has    little    peneral 
knowlt'djrj  of  analo^'iral  variation  in  other  groups  and 
11.  other  countries,  by  which  to  correct  his  first  im(»res- 
>   >:i>.      As  he  extends  the  range  of  his  observations,  \w 
will   meet  with   moro  cases  of  difficulty;    for  lie  will 
tiuounter  a  greater   numl)er   of  closclv-allied    forms. 
Hilt  if  his  observations  be  widely  extcn<led,  he  will  in 
tiie   end    generally   l»e    enabled  "to    make  up   his  own 
mind  wiiich  to  call  varieties  and  which  sjte.ics  ;  but  he 
will  succeed   in  tliis  at  the  e.vpense  of  admitting  much 
variation, —and  the  truth  of  this  admission  will  often 
l>e  disputed  by  other  naturalists.     Wben.  moreover,  lie 
■omes  to  .study  allied  forms  brought  fnun  countries  not 
now  continuous,  in  wbiih  case  he  can   banllv  hope  to 
rlufi  tbe  intermediat«>  links  between  his  doubtful  forms, 
iie  will  have  to  trust  almost  entirely  to  analogy,  and' 
his  diificiilties  rise  to  a  climax. 

V  r.  uijiiij  iir,  i  icar  line  oi  deniaicatioii  haii  as  yet 
been  drawn  between  species  and  sub-species— that  is, 
the  forms  which   in   the  opinion  of  some   naturalist* 


48 


ON  THE   ORIGIN    OF   8PECIES 


ror'ie  very  noar  to,  tint  do  not  quite  arrive  at  the 
ruuk  of"  spt'cit's  ;  or,  a^.iiii.  betweori  sul>-spooies  ami 
vc«'ll-inarkf(i  varieties,  or  l>etwiHMi  !t,'-<sor  varieties  and 
iii<iivi(Jii;ti  <lirtereiK-es.  i'liese  ditfereiiees  blend  into 
•«irli  «itlier  in  an  insensible  series  ;  and  a  series  im- 
j)resses  tbe  mind  with  llie  idea  of  an  actual  passaije. 

Hence  !  look  at  individual  ditferences,  thouijh  of 
small  interest  to  the  systematist,  as  of  hiirh  importance 
for  IIS,  as  bein^  the  first  step  towanls  sucii  sli^'bt 
varieties  as  are  barely  thou;: lit  worth  recording;  m 
work*  on  natural  history.  And  I  look  at  varieties  which 
are  in  any  de:,nee  more  distinct  and  permanent,  as  steps 
leadi!!::^  to  more  stron^lv  marked  and  more  |)ermanent 
varieties  ;  and  at  these  latter,  as  leading?  to  sub-species, 
and  to  species.  'Hie  pa^ssafje  from  one  sta^e  of  ditl'erence 
to  another  and  higher  stage  may  be,  in  some  cases, 
due  merely  to  the  long-contiinied  action  of  different 
physical  conditions  in  two  different  regions ;  but  I 
riave  not  much  faith  in  this  view  ;  and  I  attribute  the 
passage  of  a  variety,  from  a  state  in  which  it  differs 
very  slightly  from  its  parent  to  one  in  which  it  differs 
more,  to  tlie  action  of  natural  selection  in  accumulating 
(as  will  herejifler  be  more  fully  explained)  differences 
of  structure  in  certain  definite  directions.  Hence  I 
believe  a  well-marked  variety  may  be  called  an  in- 
cipient species  ;  but  whether  this  belief  be  justifialde 
must  be  judged  of  by  the  general  weight  of  the  several 
facts  and  views  given  throughout  this  work. 

It  need  not  be  supposed  that  all  varieties  or  incijiient 
species  necessarily  atUiin  tlie  rank  of  species.  lliey 
may  whilst  in  this  incipient  state  l>ecome  extinct,  or 
they  may  endure  as  varieties  for  very  long  periods,  as 
has  been  shown  to  be  t!ie  case  by  Mr.  U'ollaston  with 
the  varieties  of  certiiin  fossil  land-shells  in  Madeira. 
If  a  variety  were  to  flourisli  so  as  to  exceed  in  numbers 
the  parent  species,  it  would  then  rank  as  the  species, 
and  the  species  as  tlie  variety  ;  or  it  might  come  to 
supplant  and  exterminate  the  parent  spe«'ies  ;  or  both 
niiirlit  co-exist,  and  both  rank  as  independent  species. 
Hut  ^e  shall  bcreiifter  have  to  return  to  this  subject. 


VARIATION   LNDKR    NATURK  49 

From  llie^P  remarks  it  will  h«.  ,..,,„  tliat  I  In.k  it 
•)io  term  .pecios,  as  one  arbitnuily  ^nven  for  the  sake 
■.f  c-otiv,.„,ei.ce  t.)  a  set  of  in.lividuals  oloselv  re<...nil.lii,.r 
".i'  M  other,  aiKi  that  it  docs  not  ossetitiallV  (lifrnr  fr..-M 
he  term  variety,  uliich  is  trive.i  to  less  ".iistiiict  a,.] 
^u„e  HurtuatMi^r  forms.  The  term  va  ietv,  Htzrin  in 
".t„,,;ins(m  with  mere  indivi.l.ial  ditTen-nVes,  is  a].,, 
Hn.iied  arl.itrarily,  and  f(»r  mere  convenience'  sake. 

'.luded  by  theoretical  considerations,  I  thoiit^lit  that 
>o'ne  intorestinif  resnlts  mi-ht  he  <.hfiined   in    re-a-d 
to  tlie  nature  and  relations  uf  the  species  whi.di  vnrv 
most,  hy  tahiihitiiiir  all  the  varieties  in   several   welf- 
worke.l  floras.      At  rirst  this  seemed  a  simple  task  ;  hwt 
•  V;     •  ;\*'*^'^«"'  to  «••">"!  I  am  much  indel.ted  for 
v.Mial.le  advice  and   assistance  on   this   snhject,   soo„ 
.'ouvinced  me  that  there  wore  many  difficulties,  as  did 
^iif'so.,.,ently  Dr.  Hooker,  even  in  stronjrer  terms.      I 
shall   reserve   tor   my   future   work    the    discussion   of 
these  difTi.Milties,  and  the  tahles  themselves  of  the  pro- 
pcrtional  numhers  of  the  varying  species.      Dr.  Hooker 
[permits  me  to  add,  that  after  having  carefully  read  n.v 
'ninuscnpt,  and  examined  the  tahles,  he  thinks  that 
the   to  low.ngr  sfitements  are  fairly  well   estal.lishe.1 
l.ie  whole  subject,  however,  treated  as  it  ne<-essarilv 
here  19  with   much  brevity,  !»  rather  perplexing,  and 
ahusions  cannot  he  avoided  to  the  'stniirile  for  exist- 
ence'duerpnco  of  character,'  and  other  questions, 
hereatU'r  to  he  discussed. 

Alph.  de  Candolle  and  others  have  shown  that  plants 
••^hu-h  have  very  wide  ranges  generally  present  varieties ; 
in<l  this  might  have  been  expected,  as  they  l,ecome 
'■X posed  to  diverse  physical  conditions,  and  a«  tli..y 
•oM.o  into  competition  (which,  as  we  shall  hereafter  see, 
N  a  tar  more  important  circumstance)  with  different 
-ets  of  organic  beings.  Hut  my  tables  further  show 
Uiat  m  any  hrnited  country,  the  species  which  are 
must  common,  that  is  abound  mo^t  ir,  i.wjjyM....) .  „j.,i 
aie  species  which  are  most  widely  diifused' within  thVir 
<nvM  country  (and  this  is  a  different  consideration  from 
•n.le  range,  and  to  a  certain  extent  from  common nasa) 


to 


ON   THK   OlUlilN    OF  SPK(  lES 


% 


n 


i)*!oii  eive  rise  to  varieties  KuiTiciontly  well  marked  to 
K.'se  heeii  rertudcd  in  lujtaiiical  works.  Hence  it  \*> 
tii»'  niK^t  fiiturihhin^,  or,  as  they  m.'ty  !«'  called,  the 
lotiiiuant  species, — those  which  raiitre  wid»>]y  over  the 
woilii,  are  the  most  tlitiu^ed  in  thiir  own  country,  and 
are  the  nio.il  numerous  in  individual^,  which  oftenerft 
produce  well-marked  varieties,  or,  ius  I  consider  them, 
iiici|iicnt  species.  And  this,  jM-rhaps.  iniuht  iiave  ht'en 
anticipated  ;  tor,  as  \arieties,  in  order  to  tecorne  iu  anr 
(le;jree  permanent,  necessarily  have  to  strutrtfle  with 
tlie  ollit-r  inhahitiints  ot  the  C'  intry,  the  species  which 
arti  alnatly  dominant  will  he  lit-  most  likely  to  yield 
otisprinL'.  which,  thoiit;li  in  some  slijfhl  decree  modi- 
;u(l,  still  inherit  tlii>se  a<lvanta::e.N  that  enabled  their 
[)arent.>-  to  hecome  dominant  over  their  com[(atriota. 

If  the  plants  inhahiting'  a  country  and  descrihed  in 
anv  lloia  he  divided  into  two  e(jual  masses,  all  those 
in  the  lar^rer  yenera  heintr  placed  on  one  hide,  and  all 
tho<e  in  the  smaller  genera  on  the  other  side,  a  some- 
i>  liat  lar;rer  numher  of  the  very  common  and  much 
|l!tlll^ed  or  dominant  species  will  he  found  on  the  side 
(.f  the  larjrer  genera.  'I'his,  ;i{;ain,  miiiht  have  been 
anticipated  ;  for  the  mere  fact  of  many  specie.«  of  the 
s.ime  ^enus  iiihahitiiiff  any  country,  shows  that  there 
i>  sotiiethinf;  in  the  or;ranic  or  inortjanic  conditious 
ui  thai  country  favourahle  to  the  trenu.- ;  and,  conse- 
quently, we  mif;ht  have  expected  to  have  found  is 
tiie  lart^er  ^'•eiiera,  or  those  includmjj  many  species,  a 
larire  proportional  numher  of  dominant  sjiecies.  Uut 
•■o  many  causes  tend  to  obscure  this  result,  that  1  am 
surprised  that  my  tables  show  eveii  a  ^mail  majority 
on  the  side  of  the  lartrer  jjenera.  I  will  here  allude 
to  only  two  causes  of  obscurity.  Fresh-water  and  salt- 
lovinir  plants  have  generally  very  wide  rariijes  and  are 
much  (htfuaed,  but  this  seems  to  he  connected  with  the 
nature  of  the  stations  nihabited  by  them,  and  has  little 
or  no  relation  to  the  size  of  the  <renera  to  which  the 
gpecioH  tieiong.  Ap^ain,  planum  low  in  the  scale  of 
or^anis^ition  are  generally  much  more  widely  dilTused 
than  plants  higher  in  the  scale  ;  and  here  agaiu  there 


VAIUATION    UNDKR    XATCRE  5i 

f  no  rlnso  relation  to  the  RJze  of  tlie  Kf^'iera.  Jhe 
r.TiiHeof  Iowly-or;r;ttiised  plaiita  raii^riiur  widely  will  be 
J.M  ussed  in  our  cliapter  on  ffeo^rraplii.-al  distn'hution. 

1  rom  lookintf  at  epccies  as  <,uly  Htronuly-niurkfd 
aiMl  wvll-dt'fuied  vnrietii's,  I  waa  led  to  anticipate  that 
lh»'  species  of  the  l.irtrer  ^'cnera  in  each  rountrv  would 
u/i.'ner  present  varieties,  than  the  8i)e<ies  of  the  Hmaller 
►T'-nera  ;  f<»r  wherever  many  closely-related  specie*  (i.^. 
-p-cies  of  the  s.irne  jfenusy  have'hocn  forn>e<l,  m.-uiv 
varieties  or  incipient  soecies  ouiclit,  a«  a  ^a-neral  rule, 
to  he  now  forming.  Where  many  larj^e  trees  trrow,' 
wfc  expect  to  fnid  eaplinjfg.  U'he're  many  specieM  of 
a  jeuus  have  been  formed  throut^h  variation,  circum- 
Htauces  have  heen  favourable  for  variation  ;  and  hence 
we  initrht  expect  that  the  circumstances  would  jfenerally 
be  still  favourable  to  variation.  On  the  other  hand, 
if  wc  look  at  each  species  as  a  sjKicial  act  of  creation,' 
there  is  uo  aj. parent  reason  why  more  varieties  should 
occur  in  a  jfroup  having  many  species,  than  in  one 
having  few. 

It)  test  the  truth  of  this  anticipation  I  have  arranged 
the  i.laati  of  twelve  countries,  and  the  coleopterous 
m-Hcts  of  two  districts,  into  two  nearly  equal  masses, 
the  species  of  the  larger  genera  on  one  side,  and  those 
of  the  smaller  genera  on  the  otlier  side,  and  it  baa 
nivanahly  proved  to  be  the  case  tlial  a  larger  pro- 
pnrtiv>n  of  tiie  species  on  the  side  of  the  larger  genera 
i-r.-seut  varieties,  than  on  the  side  of  the  smaller 
g.M,era.  Moreover,  the  species  of  the  largo  genera 
winch  present  any  varieties,  invariably  present  a  larger 
aver.-i^-e  number  of  varieties  than  do  the  species  of  the 
«inuil  genera.  Hoth  these  re.«ult-s  follow  when  another 
divis-on  18  made,  and  when  all  the  smallest  genera, 
«rith  tr,^m  only  one  to  four  species,  are  absolutely 
deluded  from  the  tables.  These  facts  are  of  plain 
Firnilicalion  on  the  view  that  species  are  only  strongly- 
mf»rked  and  permanent  varieties  ;  for  wherever  many 
Bf."  cjus  of  the  sanie  genus  have  been  !  )rmed,  or  where, 
1'  ^H  may  use  the  expression,  the  manufactory  of 
«,>".:ie8  has   been  actire,  we  ought  generally   to   find 


.Hji 


fii 


mh 


':.« 


.',2 


(>\     IHK    OIIKWN    OK    Sl»K(  II-^S 


H 


th«>  niamit.u'tory -lill  in  Jictioti,  mnro  osppciilh  V"  "f" 
iiave«n(>rv  rt';»Miri  to  iu-lii'vo  llir  [iri»''(ws  of  miiii'iractur 
intr  now  fpt'i'ios  to  be  a  slow  ono.  Ami  this  cert.urily 
is  'liccase.  if  \;»ri(>ti(>B  ho  looktMl  at  x*!  incipient  -.[lO.ieH; 
for  my  Uih'os  rhNirly  show  as  a  troru'ral  riih»  thaf, 
wlitTpviT  niariv  species  of  a  i^orius  have  heen  forineil. 
ih'i  sj)t'(ii>s  of  iliit  jjenns  pre-iont  a  ninnher  of  varieties, 
that  is  of  ineijiii'iit  species  heyoiid  thrt  averairo.  It  i'^ 
not  tliat  all  larire  >>^eniTa  are  now  varviii^'  niucli,  and 
are  thus  increa«iiiir  m  the  numher  of  their  species,  or 
that  no  sTnall  i,'eiiera  are  now  varyinsf  and  increa«iiuf  ; 
fo»-  if  this  }iad  liecii  so,  it  woiiM  Iiave  hec  fatal  to  my 
theory;  inisTiiiich  as  ijeohiyy  plainly  tolls  js  that  stnal 
irenora  have  in  tlu!  la[»so  of  time  often  increaseil  tfroatly 
in  size  ;  ami  that  lar:;o  yenora  have  often  come  to  tht>lr 
ni  i\ini;»,  (hvlined,  ami  dis.ijipearod.  All  tliat  we  want 
l<>  sliow  is,  that  where  many  specioM  of  a  cenus  have 
been  formed,  on  an  aver;if;o  many  are  still  formiiiy  ; 
and  this  holds  ^ood. 

There  are  other  relations  between  the  species  of 
lart!:o  tfcnora  and  their  recorded  varieties  which  deserve 
notice.  We  have  seen  tliat  there  is  no  infallible 
criterion  by  which  to  distintjuish  ispeciea  and  well- 
marked  varieties  ;  and  in  those  cases  in  which  inter- 
niodiate  links  h.ive  not  been  found  between  doubtful 
forms,  naturalists  are  compelled  to  come  to  a  deter- 
mination by  the  amount  of  difference  between  the-n. 
judjj:iiitr  by  analotry  whether  or  not  the  amount  suffices 
to  raise  one  or  both  to  the  rank  of  species.  Hence 
the  amount  of  difference  is  one  very  important  criterion 
in  settlinti:  whether  two  forms  should  be  ranked  as 
species  or  varieties.  Vow  Fries  has  remarked  in  retrard 
to  plants,  and  VV'&stwood  in  reirard  to  insects,  that  iu 
larije  jfenera  Uie  amount  of  ditference  between  the 
species  is  often  exceedinjrly  small.  I  have  endeavoured 
to  test  this  numerically  by  averages,  and,  as  far  as  my 
impertect  results  ffo,.  they  confirm  the  view.  1  have  also 
consulted  some  sag^acious  and  experienced  r)bserver8, 
*nd,  after  deliberation,  they  concur  in  thi^  view.  In 
tJiis  respei't,  therefore,  the  species  of  the  larger  genera 


i^^m^m^^mH'^^^mmMm 


VARIATION    ■■  NDER    NAI'I  UK 


."ia 


r»'»-»'itiitiL  varietich,  more  than  do  the  -jK-cit's  ot  the 
Ktn;.lU'r  jfoiii-ra.  Or  the  case  may  l.t-  imt  m  aiiotlit-r 
v;iy,  and  it  may  bo  said,  that  in'  tin-  larLMT  ^.-ciutu, 
.ti  "Inch  a  numlier  of  varifiii's  or  incipient  ■.pci-ies 
t'Toatcr  than  the  avera«fe  are  now  man n tact urinu,  many 
ot  the  K[i<'(i»*s  already  manufactured  .still  to  a  i-ertjiin 
e\trnt  re.-eml.le  varieties,  for  they  dirij-i  from  each 
other  by  a  less  than  usual  amount  of  ditference. 

.M(»reover,  the  s|«'cies  of  the  larjre  f^ei  .  ra  are  related 
to  caih  other,  in  the  same  maimer  as  the  varieties  ol 
any  one  species  are  related  to  each  other.  No  natur- 
alist pretends  that  all  the  species  of  a  t:enus  aree«|ually 
duitinct  from  each  other;  they  may  generally  he  divided 
nitt)  sub-cenera,  or  sections,  or  le.sser  croups.  A>  Fries 
irds  well  remarked,  little  groups  o*  s{>ecies  are  generally 
clustered  like  satellites  around  certain  other  sptcies'. 
And  what  ?.re  varieties  but  groups  of  forms,  uneijually 
related  to  each  other,  and  clustered  round  certain 
forms— that  ia,  round  their  parent->pe(  ies.'  I'lidoubt- 
":!y  there  is  one  most  important  point  ot  dirterenre 
iM'twoen  varieties  and  species  ;  namel\ .  that  the  amount 
•1."  diHereuee  between  varieties,  when  compared  with 
f  ch  other  or  with  their  parent-species,  i.>  much  le»>s 
li.an  that  between  the  species  of  the  same  trcins.  But 
mien  we  come  to  discuss  the  princijde,  as  1  call  it,  ot 
I)  x.-rirenco  of  (  haracter,  we  shall  see  how  tliis  may  be 
explained,  and  how  the  lesser  diHercnce>  between 
vaiieties  will  tend  to  increase  into  the  >:reater  ditier- 
ei.ces  between  species. 

lliere  is  one  other  jKiint  which  seems  to  kih  worth 
.lotice.  \'arietiesf{enerally  have  much  re-tricted  ranges: 
;':i  statement  is  indeed  scarcely  more  than  a  truism, 
'  ir  if  a  variety  were  found  to  have  a  wider  rany^e  than 
tiiat  of  it«  supposed  parent-species,  their  denominations 
i'.irhl  to  be  reversed.  Hut  there  is  also  reason  to  l..-lieve, 
tiiat  tluMje  species  which  are  very  closel\  ailie«l  to 
oiher  species,  and  in  so  far  re^enil.le  varieties,  often 
'"uch  restricted  nni'^es.      hor  instance    ." 


W 


.it.M)n  has  marked  for  me  in  the  well  si i ted  l^.ndou 


(.HU.U.rue  of  plants  (4th  edition)  tjy  j.lauti  which 


are 


M 


M  ON  TIIK  OHKilN    OF  SI'KCIKS 

thcn.i.i  ranke<l  as  s,.o.-ie«,  but  which  »'«;-""-'ff,'^  "^ ;! 

t),0M,  r,  ,  roputoa  ^l.-  i-  ra.uM'  on  an  averatfe  over  ■  j 
of  th«  ,.ro!-ince«  into  whuh  Mr.  U  atson  »'-  J'-;  •;* 
(Jre.it  HriUiii.  Now,  in  thw  name  cat.h.r-ie,...Uckuow- 
le.luMMl  varmDi;^  aro  ro.or.l.Ml,  an.l  th..>o  rantre  over  ^  7 
province.  ;  wh.rea..  the  npcMen  to  whuh  the-^e  varw.t.e- 
UloMu'  ranir.'  ove-  lAll  provinre..  N.  that  the  a.  know- 
.  .M-ri  vari.t.os  have  v.ry  nc.rly  t  h.  -'"^Z^;^.^';^"* 
AV..raco  ranirn,  as  have  those  very  ch.M'ly  alhe<l  tormn, 
markid  for  mo  hy  Mr.  NN'ati^on  aM  .louhUol  sn.-ru'S  but 
who  h  areal-uostutmersally  ranked  by  UriUnl.  l»otan.-t* 
a;*  tfo(Ml  aiitl  true  ni)Oc;eH. 

Finally,    then,     vunet.es    have    the    Ham"    general 
..hara.U.'rH  as  species,  for  they  cat.not  be  <i,stn.Ru,.lu.d 
fr.n>    .,....ies,--exco,.t,    fir.dy,    by    Uie   discovery    of 
„t^.rm',iiate    link.n^    forms,   and    the   occurrence    of 
s.,.h  liak"-  cannot  atfiH-t  ihf  actual  characters  of  the 
form-*  vvlmh  they  connect;  and  except,  ^ec<mdly.  by  a 
cJZm  amount  of  ditference,  for  two  torms.  tl  dn  ennK 
vt^little.  are  jfenerallv  ranke.1  as  vanel.e.,  no  w.lh- 
sSindin^'  that  intennod.ate  linki.iK  ^^^ms  have  not  been 
disc     e^^^   ;  but  the  amount  of  ditference  considered 
ueces^rv  t^  pve  to  two  forms  the  rank  of  ^pecen  « 
quite    maehnite.      In    genera   havn,»,    r°''th«'tnecieS 
iverace  number  of  si>ecie8  in  any  country,  the  b  >e»  les 
of  ti^se  genera  have  mor-.  than  the  average  numW  of 
varieties       In  h.rge  genera  the  «pecies  are  apt  t«  be 
closely,  hut   unoMually  allied   together,  forming  l.Ue 
c  u.u-r     roun<i   cir-.in  species.     Sneces  very  clos«ly 
a   u-d    to    otlior    specie,    apnarentiy    have    restncted 
ranges       In  all  thU  several  resi»ecta  the  spec.es  of 
Hr-e  L'euera  present  a  strong  analogy  w^Ui  varieties. 
And    we   c^n    clearly    under^Und    the.e  ^f  »«^««'.   |' 
species  have  once  existed  as  varieties,  and  ij-je  ^nus 
o^tginated:    v^h.-roas,    these  -alopes  are^utUrly   m- 
explicable    if  each     bpecien     aas    ucua    i.i-it  ;■  

"  We\ave,  also,  seen  that  it  ifl  the  most  tloun^hing 


rmj^'m^  ^itfrr:^;;^^- 


VAKIATION    UNDKK    NAU  KK 


M 


or  < 


;lomin;»nt  npv.  irn  of  tlie  l.iru'or  tfiMU-ni  wlii.li   ..n  an 


ist  ;  aiiM  varieti«'S,  .-w  wo 


lull  ) 


IMT.lt'lT 


iTor.uf"  varv  hp...  ,  i     ,    .       . 

^(H>  tend  to  *»'c».in»^  .niiv.Ttnl  mtn  now  hikI  di-tiri.t 
,tMM  uw.  Hie  lftrir«T  ir.'ti.'ra  thus  ttMi.l  to  Iktoiu^  l.iri:«'r; 
and  throutrhowt  ii.iturp  th«  forms  of  lif«  .*ln.h  .iro  imw 
(Inniiiiaiit  tiMid  to  li.M.mi.'  'ill  moro  «lumiii;iiit  !•>  l.-;»Mn< 
mativ  mo<lin.>.l  .iii'i  tlorninniit  ar-^riMi.l.ints.  But  l-y 
uteps  lieroartrr  to  ».«  pxplninf*!,  tho  lar-rr  jfftHT.i  JiNo 
Iru.l  tx.  hr.'.ik  -ip  into  -m:»ll«T  ir.Tieni.  AikI  thus,  the 
fonriH  of  lif*?  thro. it'hniit  the  universe  l>oconic  (lnJ<le.l 
into  trroupH  Huborditiato  t«  jfroups. 


I! 


CHAPTER    HI 


STKl'UGLK    KOH    EXiSTKNCE 


n 


n 


Bears  on  natural  sekcliun  —  Tlie  term  used  In  a  wide  seiine  — 
Ceoinetrual  fMnvcis  uf  increase  — llapid  irurease  of  naturalised 
iiiiiniiils  and  iilaiits— Nature  o(  the  checks  to  Increase— ('(im- 
lieliti m  univctHal  —  Klfecta  of  climate  —  I'rotoetlon  from  the 
numlier  <>f  iiidividuaU— (Jornplex  relatiuns  of  all  animals  and 
lilaiils  tliroUKliout  nature — Struggle  for  life  most  severe  between 
individuals  and  varii'ties  of  the  same  species ;  often  severe 
between  species  of  the  same  genua— The  relation  of  organism 
to  organism  the  most  important  of  all  relations. 

Hkkoue  enterine;'  on  the  subject  of  this  cliapter,  1  must 
make  a  few  preliminary  remarks,  to  sliow  how  the 
strufT^'le  for  existonre  bears  on  Natural  Selection.  It 
has  been  seen  in  the  last  chapter  that  among-st  orjrauic 
beiiiffs  in  a  state  of  nature  there  is  some  individual  vari- 
ability :  indeed  1  am  not  aware  that  this  has  ever  been 
disj)uted.  It  is  immaterial  for  us  whether  a  multitude 
of  doubtful  forms  be  called  species  or  sub-species  or 
varieties  ;  what  rank,  for  instance,  the  two  or  three 
hundred  doubtful  forms  of  British  plants  are  entitled 
to  hold,  if  the  existence  of  any  well-marked  varieties 
Imj  admitted.  Hut  the  mere  existence  of  individual 
varialiility  and  of  some  few  well-marked  varieties, 
thou^^h  necessary  as  the  foundation  for  the  work,  helps 
us  but  little  in  understandinjf  how  species  arise  iu 
nature.  How  have  all  those  exquisite  adaptations  of 
one  part  of  the  orj^'-anisation  to  another  part,  and  to  the 
conditions  of  life,  and  of  one  distinct  ortr,  .ic  beinj.""  tn 
another  bein^,  been  perfected  ?  We  see  tliese  beauti- 
ful co-adaptatious  most  plainly  la  tlie  woodpecker  and 

50 


STRUGGLE  FOR   EXiSTENCE 


67 


IUl^tletoe  ;  and  only  a  little  less  plainly  in  the  humblest 
parasite  which  ('lin«rs  to  the  hairs  of  a  (juadriiped  or 
i'tittliers  of  a  hinl  ;  in  the  structure  of  the  l>eetlo  which 
rl.ves  tliroutjh  the  water;  in  the  plumed  seed  which  is 
wafted  by  the  gentlest  I)reeze  ;  in  short,  we  see  beauti- 
ful adapUitions  everywliere  and  iu  every  part  of  the 
urtfanic  world. 

A^ain,  it  may  he  asked,  how  is  it  that  varieties,  which 
1  have  called  incipient  species,  become  ultimately  con- 
verted into  fTood  and  distinct  specie.s,  which  in  most 
<ii>es  obviously  differ  from  each  other  far  more  thau  do 
the  varieties  of  the  same  species  ?  How  do  those  jrroups 
of  species,  which  constitute  what  are  called  distinct 
genera,  and  which  differ  from  each  other  more  than  do 
ilie  species  of  the  same  genus,  arise  f  All  these  results, 
ii>  we  shall  more  fully  see  in  the  next  chapter,  follow 
Hum  the  strugjrle  for  life.  Owinjf  to  this  strug^^fle  for 
life,  any  variation,  however  slight,  and  fr"^m  whatever 
cause  pro(  'eding,  if  it  be  in  any  degree  pi  lable  to  an 
iiidividual  of  any  species,  iu  ita  intinitely  complex  rela- 
uons  to  other  organic  beings  and  to  external  naturt.^ 
will  tend  to  the  preservation  of  that  individual,  and 
will  generally  be  inherited  by  its  offspring.  'Hie  off- 
sj)riug,  also,  will  thus  have  a  better  chance  of  surviving, 
for,  of  the  many  individuals  of  any  species  which  are 
jd'riodically  born,  but  a  small  number  can  survive, 
i  have  called  this  principle,  by  which  each  slight  vari- 
ation, if  useful,  is  preserved,  by  the  term  of  Natural 
^election,  in  order  to  mark  its  relation  to  man's  power 
'>t  selection.  ^V'e  have  seen  that  man  by  selection  can 
lerlaiuly  produce  great  results,  and  can  adapt  organic 
beings  to  his  own  uses,  throutrh  the  accumulation  of 
blight  but  useful  variations,  given  to  him  by  tiie  hand  of 
Nature.  But  Natural  Selection,  as  we  sliall  hc;;pafter 
see,  is  a  power  incessantly  ready  for  action,  and  is  afi 
immeasurably  superior  to  man's  feeble  efforts,  a^  the 
works  of  Nature  are  to  those  of  Art. 

Wv  will  now  discuss  iu  a  litUe  more  detail  the  stru-rKif 
for  existence.  In  my  future  work  this  subject  shall  Ixj 
treated,  ".*?  it  well  deserve*,  at  much  greater  length. 


^11 


I' 


w 


h 


58  ON    THE   ORIGIN    <  >K   hPE(  IKS 

Vhp  plder  il<^  randollf*  and  I. veil  have  lartrely  and  j.hi!  >- 
Hoi>lji':ally   -liown  tl„it  al!  lirL'-anic  beiiiL^s  an?  p\p(>--d 
to  -^.'Vfro'.oiiii.etitioii.      In  rcirard  to  planb*,  no  one  l-as 
tn'.-ilo.l   this   suhjfct  with   more  wpirit  and   ahility  thnn 
W.  Horl>or%  Do.inof  \!aiirh<>-t.T.  evi.!.",-tlv  the  n'-ult 
of  his  ;.-Te.-it  horticultural  knowlodL'-e.      Nothintr  i;*  easier 
than    to   .\ilinit    in    words    tlic    trutli   of   the    universal 
.^tru^'l;lo  for  li fo,  or  more  dilficult— at  least  1  have  found 
it  HO— than  ron-tantly  to  hear  this  conclusion  iu   mind. 
Yet   unless   it  lie  thorou^Mily  entrrained   in  the  mind,  I 
am  corivuiced  that  the  whfdo  ec(uioniy  of  nature,  with 
every  fact  on  distrihution,  rarity,  ahundance,  extinction, 
and  variation,  will  he  dimly  seen  or  quit*  misundersUM'*. 
We  hehold  tlio  face  of  nature  bright  with  >;ladnesM,  we 
ot\en  see  superaliundance  of  food  ;  we  do  not  see,  or  we 
forsret  tliat   tlie  hirds  which  are  idly  sintrinj,'  round  U8 
mostly  live  on  insectj*  or  see<l«.  and  are  thus  constantly 
dehtroyintr  life  ;  nr  we  forget  how  largely  these  sont!>.ters, 
or  tlieir  een-i.  or  their  nestliniT?,  are  destroyeil  hy  hirds 
and   beasts  of  prev  ;   we  do  not  always  l>ear  iu  nnnd, 
tiuit  thougli  food  may  he  now  superabundant,  it  is  not 
so  at  all  seasons  of  each  recurring  ye^r. 

I  should  piimise  that  I  use  the  term  Strutrgle  for 
Existeiicft  in  a  large  and  metaphorical  sense,  iuciudhii; 
dependence  of  one  being  on  another,  and  includins; 
(which  is  more  important)  not  only  the  life  of  the  uiui- 
vidual,  but  success  in  leaving  progeny.  Two  canine 
animals  in  a  time  of  dwirth,  may  be  truly  said  to 
stru:rgle  with  each  other  which  shall  get  food  and  live. 
But  a  plant  on  the  edt^e  of  a  desert  ia  said  to  struggle 
for  life  against  the  drought,  though  more  properly  it 
should  be  said  to  be  dependent  on  the  moisture.  A 
pl.mt  wliieli  annually  produces  a  thousand  seeds,  of 
which  on  an  average  onlv  one  comes  to  maturity,  may 
be  more  truly  said  to  struggle  with  the  plant^s  of  the 
same  and  other  kinds  which  already  clothe  the  groun(L 
Ibe  mistletoe  is  dependent  on  the  apple  and  a  few  other 
trees,  hut  can  only  in  a  far-tetched  sense  be  said  *o 
Btru^ri^le  with  these  trees,  for  if  too  many  of  those  par*- 
Bites  tfrow  on  the  same  tree,  it  will  languish  and  di* 


STRICidLK    FOR   EXISTENCE 


59 


But  9«ver.il  sce-llini.'  mistletoe?,  trrowiri;:  close  toirether 
on  Mie  win\«  braiicli,  may  more  trtily  be  said  to  ntrue<r!« 
with  ricli  other.  As  th«  mistletoe  is  diss^emiiiateii  i>y 
bin!-',  iU  existenre  do[>en<l9  on  birds  ;  and  it  may  met*- 
pl'orically  be  said  to  titriiuijlp  with  other  fruit-bearintf 
planta,  in  order  to  tempt  binis  to  devour  and  thus 
disseminate  itg  seeds  rather  than  those  of  other  j)l.'\utM. 
In  these  several  sensfs,  which  pass  into  eacli  other,  I 
a»o  for  convenience'  sake  the  general  term  of  strujjgle 
for  existence. 

A  strutrtjle  for  existence  inevitably  follows  from  the 
hii^h  rate  at  which  all  ortranic  beinjjs  tend  to  increase. 
Every  beinj^,  which  during  its  natural  lifetime  produces 
several  eggs  or  seeds,  must  sutFer  destruction  during 
some  period  of  its  life,  and  during  scmie  season  or  occa- 
sional year,  otherwise,  ou  the  principle  of  geometrical 
increase,  its  numbers  would  quickly  become  bo  in- 
ordinately great  that  no  country  could  support  the 
product  Hence,  as  more  individuals  are  produced 
than  can  possibly  survive,  there  must  in  every  case 
be  a  strugjf le  for  existence,  either  one  individual  with 
another  cf  the  same  species,  or  with  the  individuals  of 
distinct  species,  or  with  the  pby^  cal  conditions  of  life. 
It  is  the  doctrine  of  Malthus'  applied  with  manifold 
force  to  the  whole  animal  and  vegetable  kingdoms;  for 
in  this  case  there  can  be  no  artiticial  increase  of  food, 
and  no  prudential  restraint  from  marriage.  Although 
some  species  may  be  now  increasing,  more  or  less 
rapidly,  in  numbers,  all  cannot  do  so,  for  the  world 
would  not  hold  them. 

There  is  no  exception  to  the  rule  that  every  organic 
being  naturally  increases  at  so  high  a  rate,  that  if  not 
destroyed,  the  earth  would  soon  be  covered  by  the 
progenv  of  a  single  pair.  Even  slow-breeding  man  has 
doui)led  in  twenty-five  years,  and  at  this  rate,  in  a  few 
thousand  years,  there  would  literally  not  be  standing 
room  for  his  progeny.  Linnieus  h<i«  calculated  that  if 
an  annual  plant  produced  only  Iwu  nee*!.'*^ — aiid  mere  ia 
no  plant  so  unproductive  as  this—and  their  seedlings 
next  year  produced  two,  and  so  on,    then  in  twenty 


80 


ON   THE   ORIGIN    OF  SPECIFY 


m 


jt^ira  there  would  1)6  a  million  plants,  Tlie  elephant  it 
re<  koiied  the  slowest  breeder  of  all  known  animals, 
and  1  have  taken  8<ime  ]iainH  to  e»>tiniate  itu  proliahle 
mitiitiiam  rate  of  natural  increase:  it  will  be  under  the 
mark  to  assume  that  it  breeds  when  thirty  years  old, 
and  poes  on  breeding  till  ninety  years  old,  brinffiixg 
forth  three  pair  of  youuf^  in  this  interval  ;  i;  this  be  8o, 
at  tiie  »Mid  of  the  fifth  century  there  would  be  alivf 
dfteen  million  elephants,  descended  from  the  first  pair, 
liut  we  have  better  evidence  on  this  subject  than 
mere  theoretical  calculations,  namely,  the  numerous 
recorded  cases  of  the  astonish inj^ly  ra}iid  increase  of 
various  animals  in  a  state  of  nature,  when  circumstances 
have  been  favourable  to  them  during  two  or  three 
following  seasons.  Still  more  striking  is  the  evidence 
from  our  domestic  animals  of  many  kinds  which  have 
run  wild  in  several  parts  of  the  world  :  if  the  Ktatemeutg 
of  the  rate  of  increase  of  slow-breeding  cattle  and 
horses  in  South  America,  and  latterly  in  Australia,  had 
not  been  well  authenticated,  they  would  have  been 
incredible.  So  it  is  with  j)lanta  :  ca.ses  could  be  given 
of  introduced  plants  which  have  become  common 
throughout  whole  islands  in  a  period  of  less  than  ten 
years,  'several  of  the  plants^  such  as  the  cardoon  and 
a  tall  thistle^  now  most  numerous  over  the  wide  plaiuf 
of  I.a  Plata,  clothing  square  leagues  of  surface  almost 
to  the  exclusion  of  all  other  pl-'>.ut8,  have  been  lutro- 
duced  from  Europe  ;  and  there  are  plant*  which  now 
range  in  India,  as  I  hear  from  Dr.  Falconer,  from  Cape 
(.'omorin  to  the  Himalaya,  which  have  been  imported 
frt  in  America  since  its  discovery.  In  such  cases,  and 
fudless  instances  could  be  given,  no  one  supposes  tL<\t 
the  fertility  of  these  animals  or  plants  has  been  suddenly 
and  temporarily  increased  in  any  sensible  degree.  'ITie 
obvious  explanation  is  that  the  conditiont<  of  life  have 
been  very  favourable,  and  that  there  has  consequently 
been  less  destruction  of  the  old  and  young,  and  that 
nearly  all  the  young  have  l>een  enabled  to  breed.  In 
such  cases  the  geometrical  ratio  of  increase,  the 
result  of  which  nevCi     faih>    t<.    he  surprising,  simply 


STRL'(KiLE    FOR    EXISTENrE 


>il 


CAplnins  tn4>  ftxtnonlinarily  rapid  iiu-rease  and  wide 
'H-fijtinnof  iiatur:ili-ed  nroductioiis  in  their  new  homes. 
In  a  «tate  of  nature  almost  every  plant  prodnces  seed, 
and  amoinrst  anitnals  there  are  very  few  which  do  not 
irinually  pair.  Ilfnce  we  may  oonfidently  xssert,  that 
nil  plants  and  animals  are  toridiiitr  to  increase  at  a 
ireometrica!  ratio,  that  all  would  most  rapidly  -ititck 
every  station  in  wliicli  they  conld  anyhow  exist,  and 
that  the  ;,'enmetrical  tendency  to  increa.se  must  he 
•he(!ked  by  destruction  at  some  period  of  life.  Our 
familiarity  with  the  larer»  domestic  animals  tends, 
I  think,  to  mislead  us  :  ^  see  no  great  destruction 
fallin^r  on  them,  and  we  forj^et  tliat  thousands  are 
annually  slautflitered  for  food,  and  that  in  a  state  of 
nature  an  equal  num')er  would  have  somehow  to  l»e 
disposed  of. 

'Hie  only  difference  between  "•;;anisms  which  annually 
produce  egj^s  or  seeds  by  the  thousand,  and  those  which 
produce  extremely  t'evr,  is,  that  the  slow-hree<lers  would 
require  a  few  more  years  to  people,  under  favourable 
conditions,  a  whole, district,  .et  it  be  ever  so  lartre. 
Die  condor  lays  a  couple  of  ej^gs  and  the  ostrich  a  score, 
and  yet  in  the  same  country  the  condor  may  be  the 
more  numerou.s  of  the  two :  the  Fulmar  petrel  lays 
but  one  e^g,  yet  it  is  believe<i  to  be  the  most  numerous 
bird  in  the  world.  ( )ne  fly  deposits  hundreds  of  e^^s, 
and  another,  like  the  hippohosca,  a  sin^'le  one  ;  but 
this  difference  does  not  determine  how  many  indi- 
viduals of  the  two  species  can  be  supported  in  a  district 
A  large  number  of  ecp*  ia  of  some  imjtortance  to  those 
species  which  depeofi  on  a  rapidly  fluctuating'  amount 
of  food,  for  it  aUowg  them  rapidly  to  increa.se  in 
number.  But  the  real  importance  of  a  large  number 
of  eggs  or  seeds  is  to  make  up  for  njuch  destruction 
ftt  some  period  of  life  ;  and  this  period  in  the  great 
majority  of  ca.so8  is  an  early  one.  If  an  animal  can  in 
any  way  protect  its  own  eggs  or  younL'.a  small  number 
may  be  produced,  and  yet  the  average  stock  be  fully 
kept  !!p;  but  if  many  eggs  or  young  are  dewtroyed,  manj 
must  ie  produced,  or  the  flpeciew  will  become  extinrt. 


t ' 


62 


ON   'I  HE   ORIGIN    OF  SPK(  lES 


i 


It  would  «ufTice  to  keoj»  up  the  full  numher  of  a  tree^ 
wliich  livt'il  oil  nil  avi-ruiso  for  a  tliOii>uiid  years,  if  a 
fciii^le  (jfetl  wore  proiiiiced  once  iii  a  thous-iud  years, 
»u]'j><)sintj;  that  tUi^  seed  were  never  destroyed,  rind 
could  he  ensured  to  {germinate  in  a  hltin^'  place. 
So  tliat  in  ail  tasi'>,  the  averat^e  numher  of  any  animal 
or  plant  depends  »)nly  indirectly  ou  the  nundier  of  it*: 
egp?  or  seeds. 

In  looking'  at  Nature,  it  is  most  necessary  to  keep 
the  foretioinfr  considerations  alwavH  in  mind  -  never  to 
foiiiet  that  every  single  orjranic  heinj;  around  ufl  may 
l»e  said  to  he  Htrivinj?  to  the  utmost  to  increase  in 
numbers  ;  that  each  lives  hy  a  8trugt(le  at  some  period 
of  its  life  :  that  heavy  dotruclion  inevitahly  falls 
either  on  the  young  or  old,  durin><:  each  ^feneration 
or  at  recurrent  intervals.  Liirhtcu  any  che<'k,  militate 
the  destruction  ever  so  little,  and  the  nun»her  of  the 
species  will  almost  instantaneously  increase  to  any 
amount. 

'Ilie  causes  which  check  the  natural  tendency  of  each 
epecies  to  increase  in  uund>er  are  most  ohscure.  Look 
at  the  most  vigorous  sjiecies  ;  hy  as  mucli  as  it  swarms 
in  uumhers,  hy  so  much  will  its  tendency  to  increase 
lie  still  further  incr«^ased.  We  know  not  exactly  what 
the  checks  are  in  even  one  sin^rle  instance.  Nor  will 
this  fturpri.se  any  one  who  reilecLs  how  if^-norant  we  are 
on  this  liead,  even  in  rejjard  to  mankind,  so  incompar- 
aMy  hetter  known  than  any  other  animal.  Iliis  .suhject 
has  been  ahly  treated  hy  several  authors,  and  I  shall, 
in  my  future  work,  discuss  some  of  the  checks  at  con- 
Siderahle  len^h,  more  especially  in  regard  to  tlie  feral 
animals  of  JSouth  America.  Here  I  will  make  only  a 
few  remarks,  just  to  recall  to  the  readers  mind  some 
of  the  chief  points.  Ktrj^  or  very  young  animals  seem 
g-enerally  to  suffer  most,  hut  this  is  not  invariahly  the 
case.  U'ith  plants  there  is  a  vast  debtructiou  of  seeds, 
hut,  from  some  observations  which  I  have  made,  I 
bt'iieTe  ilitti  il  is  tht;  seenirm^s  wlncli  Suiief  most  frotn 
^ermioatinK  in  ground  already  thickl;  slocked  with 
other  plants      ^^eAdiings,  also,  ar«  destroyed  in  vatit 


STRUGGLE    FOR    EXISTP:NC  E 


Ki 


nuinhers  by  various  enemies  ;  for  instance,  on  a  piece 
of  frround  three  feet  lon^  and  tno  wiiic,  dutf  and 
rleari'<i,and  where  there  could  he  no  cliokin::  fjom 
(•iher  plants,  1  marked  all  the  sccdlintrs  of  our  ri.ilive 
weeds  as  they  cmiie  uj>,  and  out  of  the  .N/iT  no  hv-s  llian 
2.t6  were  destroyed,  chiefly  by  filugs  and  insei  t.'..  If 
turf  which  lias  long^  heen  mown,  and  the  case  \foiild  he 
'he  same  with  turf  closely  hrowsed  by  ([iiidrujteds,  he 
h  t  lo  (Trow,  the  more  vigorous  plants  trradu.illy  kill  the 
les>  vitrorous,  thoujrh  fully  trrown.  plants:  thus  out  of 
twenty  species  ffrowint'  on  a  little  jilot  of  turt  (three 
teet  by  four;  nine  species  perislied  from  the  other  sjtecier 
heiiiii"  allow  e<l  to  ^row  up  free!  v. 

1  he  amount  of  food  for  each  species  of  course  trivee 
the  extreme  limit  to  whidi  each  can  increase  ;  l»ut  very 
frO(juent]y  it  is  not  the  obtaining  food,  but  the  scrvinj; 
as  j.rey  to  other  animals,  wiiirh  determines  the  averajjc 
nuniiiers  of  a  species.  Tlius,  there  seems  to  Ik  little 
doubt  that  the  stock  of  partridtres,  grouse,  and  hares  on 
ruiy  larj^^e  estate  depends  chiedy  on  the  destruction  of 
vermin.  If  not  one  head  of  gume  were  shot  during 
the  next  twenty  years  iu  Kngland,  and,  at  the  same 
time,  if  no  vernnn  were  destroyed,  there  would,  in  all 
firobability,  be  less  game  than  at  pre>ent,  altluuigh 
hundreds  of  thousands  of  ^ame  animals  a;c  now 
iiiiiiually  killed.  On  the  other  hand,  in  some  cases, 
:is  with  the  elephant  and  rhinoceros,  none  are  destroyed 
by  beasts  of  prey  :  even  the  tiger  in  India  most  rarely 
dares  to  attack  a  young  elephant  protected  by  its  dam. 

(Jlimate  plays  an  important  pan  m  determining  tiie 
average  numbers  of  a  species,  and  {teriodic^l  seasons 
1  r  extreme  cold  or  drought,  I  believe  to  l)e  the  most 
I  fi-ctive  of  all  checks.  I  estimated  that  the  winter  of 
1  ;.'>4-5.5  destroyed  four-fifths  of  the  birds  in  my  own 
jiouuds;  and  this  ie  a  tremendous  destruction,  when 
He  rememl>er  that  ten  per  cent  is  an  extraordinarily 
H-.ere  mortality  from  epidemics  with  man.  The  action 
'I  Climate  seems  at  first  sight  to  be  quite  independent 
'•:  the  struggle  for  existence  ;  but  in  so  far  as  climate 
c,'i:ody  act«    in  reducing  food,  it  briujfrs  on  the  most 


<?4 


ON   THK   ORIGIN    OF  SI'PX'IKS 


neverft  struff^rle    hotwwn  tho   individuals,  whother  ot 
the  same  or  of  di-;tiiirt  species,  v^  liioli   sui>sist  on  th»« 
same  kiml  of  food.      Kvi>ii  when  ilim.ite,  for  instance 
extreme  .-old,  art^  directly,  it  will  l-e  the  least  vijforom, 
OP  Ihdso  v-hiih  have  jrot  least  foo<l  throui^h  the  advanc- 
in:r  winter,  which  will  -uifer  most,    ^^■hen  we  travel  from 
south  to   riortii,  or   from  a  damp  rejrion   to  a  dry,  wm 
invariahlv  see  some  species  ^'radually  :i:ettin^  rarer  aid 
rnrer,   ard    tiiially   di<apj»earintr  *,    ii'id    tho   chanjro   <>i 
climate  hein::  conspicuous,  we  are  tempte<l  to  attritni'e 
the   whole  etlot   to  its  direct  action.      Hut   this  is  a 
false  view  :   wo  forjfet  that  each  species,  even  where  it 
most  ahoiiniK,    is    constantly  sutferin;;    enormous  de- 
struction at  some  period  of  its  life,  from  enemies  or 
from  cd'iipetitors  tor  the  same  place  and  food  ;  and  if 
tlie^e  enemies  or  competitors   ho   in  tho  least  de^ee 
favoured   hy  anv   alif^ht  change  of  climate,  they   will 
iiicreape  in  inim'hers,  and,  as  each  area  is  already  fully 
stocked  with  inhahitants,  the  other  species  will  decrea.se. 
When  we  travel  southward  and  see  a  species  decreas- 
iuj   in  numhers,  we  may  feel  sure  that  tlie  cause  lies 
quite  as  much  in  other'  species  heinjj  favoured,  as  iu 
this  one  beiuir  luirt    So  it  is  when  we  travel  northward, 
but  in  a   somewhat  lesser  de^jree.  for  the  number  of 
species   •►f  all    kinds,    and  therefore    of   competitors, 
(lecre.ises  northwards;    hence  in  ^^oinff  northwanl,  or 
in  a,scend:n^:  a  mountain,  we  far  oftener  meet   witli 
•stunted  forms,  duo   to  the  directly  injurious  action  of 
climate,  than   we  do  in  proceedinff  southwards  or  iu 
descending?  a  mountain.      When  we  reach  the  Arctic 
regions,  or  snow-capped  summits,  or  absolute  desert-", 
the  strufTijle    for    life  is   almost   exclusively  with  the 
elements. 

That  climate  acts  in  main  part  indirectly  by  favour- 
iutr  other  species,  we  may  <'learly  see  in  the  prodi^ou<» 
numljer  of  plants  iu  our  {gardens  which  can  perfectly 
well  endure  our  climate,  but  which  never  becon-e 
naturalised,  for  they  cannot  cf  •  pete  with  our  native 
plants  nor  resist  destruction  by  our  native  animals. 

When  a  species,  owiiitf  to  hitrhly  favourable  circum- 


STRrOGLE   FOR   EXISTENCE 


66 


•-tances,  increase!*  inordinately  in  nunihors  in  a  small 
•.ra«;t,  epidemics — at  least,  tins  seems  jrenerally  to  occur 
with  our  jraiiio  animals — often  ensue  :  and  liere  we 
have  a  liniitiiitf  clierk  independent  of  the  slrujfjfle 
!ur  life.  Hut  even  some  of  these  so-railed  epidemics 
a]>pear  to  he  due  to  parasitic  worms,  wfiich  liavo  from 
<otne  cause,  pos»ildy  in  part  throutrh  facility  of  diffusion 
amongst  the  crowded  animals,  l»een  disprojiortionahly 
favourec!  :  and  here  comes  in  a  sort  of  Htrujftrle  hetweeu 
the  parasite  arul  its  l>rey. 

On  the  (tther  hand,  in  many  cases,  a  lar^o  stock  of 
individuals  of  the  same  species,  relatively  to  the  num- 
bers of  its  enemies,  is  ahsolutely  necessary  for  its  pre- 
■<ervati<in.  Fhus  wo  can  easily  raise  plenty  of  corn  and 
rape-seed,  etc.,  in  our  fields,  i)ecause  the  seeds  are  in 
trreat  e.xcess  conipare<l  with  the  numher  of  birds  which 
teed  on  them  ;  nor  can  the  birds,  though  having  a 
superahuiwlance  of  food  at  this  one  season,  increase  in 
numher  proportionally  to  the  supply  of  seed,  as  their 
numbers  are  checked  during  winter:  hut  any  one  who 
has  tried,  knows  how  troublesome  it  is  to  jjet  seed 
from  a  few  wheat  or  other  such  plants  in  a  jjarden  :  I 
have  in  this  case  lost  every  single  seed.  Tliis  view  of 
the  necessity  of  a  lartre  stock  of  the  same  species  for 
its  preservation,  explains,  1  believe,  some  sinj^ular  facts 
in  nature,  such  as  that  of  very  rare  plants  heinjf  some- 
times extremely  abundant  iu  the  few  spots  where  they 
do  occur  ;  and  that  of  some  social  plants  beiiiff  social, 
that  is,  abounding  in  individuals,  even  on  the  extreme 
confines  of  their  range.  For  in  such  cases,  we  may 
believe,  that  a  plant  could  exist  only  where  the  con- 
ditions of  its  life  were  so  favourable  that  many  could 
exist  together,  and  thus  save  the  species  from  utter 
destruction.  1  sliould  add  that  the  go<Ml  eltects  of 
frequent  intercrossing,  and  the  ill  etfects  ot  close  inter- 
breeding, j»rob;ibly  come  into  play  in  some  of  these  cases; 
t)ut  on  this  intricate  sulijed  I  will  not  here  enlartre. 

."•iiiiiv  ca-cs  are  on  ieo«mi  ?iuiv»iii4{  in.w  Cdiripiex  ana 
unexpecteii  are  the  checks  a;id  relations  between  organic 
l>eiugs  which   have   to  struggle   together   in  the  same 


W) 


ON   THK   ORIGIN    OF   SPECIES 


country.      1    will  pive  only  a  sluffle  instance,   which, 
thou^rh  a  Himple  ^ue,  has  interesteil  me.      In  StatforC- 
rthirt',  on  the  eNtiile  of  a  relation,  where   I   had   ample 
itifans  of  iiive><titratioii,  there  w;is  a  lar^e  and  extremely 
l.arren  heatli,  which   had  never  l»cen   tom-hed  by  the 
hand   of  man  ;  hut   several   liundred   acres  of  exactly 
the  same  n.itiire  had   heen  enclosed  twenty-five  yearn 
previously  and  planted  with  Sc.tcli  fir.      Ihe  change  in 
the  native  ve>feUtion  of  tlie  planted  i>art  of  the  heath 
was  mo.st  remarkable,  more  than  is  Kcuerally  seen  in 
passing  from  one  quite  ditferent  soil  to  another  :  not 
only  the  proportional  numbers  of  the  h<  ith-plants  were 
wholly    chan^red,    but    twelve    species    of    plants    (not 
countintf  jfra.sses  and  carices)  tlourished  in  the  planta- 
tionH,  wliich  could  not  \>e  found  on  the  heath.     The 
etfect  on  the  insects  must  have  Uvn  still  jrreater,  for 
six  insectivon)us  birds  were  very  common  in  the  planta- 
tions, which  were  not  to  be  seen  on  the  heath  ;  and 
the  heath    was    fre<iuented    by  two   or   three   distinct 
insectivorous  birds.      Hero  we  see  how  potent  has  been 
the  etfect  of  the  intrttduction  of  a  sintrle  tree,  nothing 
whatever  else  having  been   dune,  with   the  exception 
that  the  land  had  been  enclosed,  .so  that  cattle  could 
not  enter.      Hut  how  important  an  element  enclo      e 
is,  I  plainly  sjiw  near  Karnliam,  in  Surrey.      Here  there 
are  extensive  lieatlis,  with  a  few  clumps  of  old  Scotch 
tirs  on  the  dist^mt  hill-tops  :  within  the  la.«t  ten  years 
lartre  spaces  have  been  enclosed,  and  self-sown  lirs  are 
now  sprin^jiuiT  up  in  multitudes,  .so  close  to^rether  tliat 
all  caiuiot  live.     When  1  ascertained  that  these  youujf 
trees  had   not   been   sown  or  planted,  I  was  so  much 
surprised  at  their  nuribers  that  I  went  to  several  points 
of  view,  whence  I  coubl  examine  hundreds  of  acres  of 
the  unencbised  heath,  and  literally  1  could  not  see  a 
sinjfle  Scotch  fir,  except  the  old  planted  clumps.      But 
on  lookiiiij  closely  between  the  stems  of  the  heath, 
I  found  a  multitude  of  seedlings  and  little  trees,  which 
had  been  perpetually  brtmsed  down  by  tnc  cattiC.      Ic 
one  square  yard,  at  a  point  some  hundred  yards  disUnt 
from  one  of  the  old  clumps,  I  counted  thirty-two  little 


i 


iTRITKiLE    FOR    EXI^TEM  K 


91 


Uer.i  ;  and  otip  of  them,  with  twe..tv-Hix  riiiir«  oJ 
trrowth,  had  duriijtf  many  years  tried  to  raise  its  head 
above  the  stems  of  th»'  ht-ath,  ami  ha«l  failtHl.  N'o 
wonder  that,  as  soon  a-  the  land  was  enclose*!,  it  l>«- 
'  ame  thickly  clothed  with  vijforously^rrowiiifi^  youii^r  fifH. 
Vet  the  heath  was  so  extremely  harreii  and  so  extensive 
that  no  one  would  ever  liave  iniatrined  that  cattle  would 
hive  so  closely  and  etfectnally  s«'arched  it  ror  food. 

Here  we  see  that  cattle  absolutely  determine  the 
existence  of  the  ^>cotch  fir;  hut  in  several  narbt  of 
the  world  insects  determine  the  existence  of  cattle, 
i'erhaps  Paraguay  otfers  the  most  curious  insta'  'e  of 
this  ;  for  here  neither  cattle  nor  horses  nctr  dt.^-s  have 
ever  run  wild,  thouj^h  they  swarm  southward  and 
northward  iu  a  feral  state ;  and  Azara  an<l  Hentrirer 
Kave  showu  that  this  is  caused  hy  the  t:  reitter  numher 
111  Paraguay  of  a  certain  Hy,  which  lays  its  »  /jfs  in  the 
navels  of  these  animal?,  when  first  Imru.  'Ihtj  increase 
of  these  dies,  numerous  as  they  are,  mus^  ue  naliitually 
ihecked  by  some  means,  probably  by  birds.  Hence, 
if  (  ertiiui  insectivorous  birds  (whose  numbers  are  f>rob- 
ably  regulated  by  hawks  or  beasts  of  prey)  were  to 
increase  in  Paraguay,  the  flies  would  decrease — then 
cattle  and  horses  would  become  feral,  and  this  would 
(ertainly  greatly  alter  (as  indeed  I  have  observed  in 
parts  of  bouth  America)  the  vegetation  :  this  again 
would  largely  affect  the  insects  ;  and  this,  as  we  just 
have  -ieen  iu  Staffordshire,  the  insectivorous  birds,  and 
>o  onwards  in  ever-increasiruf  circles  of  complexity. 
\\  e  l)egan  this  series  by  insectivorous  birds,  and  we 
have  ended  with  them.  '  Not  that  in  nature  the  rela- 
tions can  ever  be  as  simple  as  this,  liattle  within 
iialtle  must  ever  be  recurring  with  varying  success  ; 
and  yet  in  the  lontr-ruii  the  forces  are  so  nicely 
balanced,  that  the  face  of  nature  remains  uniform  for 
lung  periods  of  time,  though  assuredly  the  merest  trifle 
would  oflen  give  the  victory  to  one  organic  being  over 
aiiutiier.  Nevertheiess  so  profound  is  our  ignorance, 
and  so  high  our  presunijjtion,  that  we  marvel  when  we 
iioar  of  the  extinction  of  an  organic  being  ;  and  as  we  do 


68 


ON    lUt:   OKKJIN   OF   SI'K(  IK> 


i  t 


n<»t  -♦'«  llie  o.m-i-.  \v«'  invoke  caUclysnis  to  ciesdlate  the 
w«)rlil,  or  iiiMMit  l.iwn  on  tlu-  diinilioii  of  tlic  forms  of  life  I 
I  Hill  t»'nii>t»Ml  U)  ixxw  one  iiioro  iiistaiuw  kIiowiiut  how 
phiiits  ami  Hiiiiiiain,  nio.-^l  rfinoto  in  th<>  scalw  of  nature, 
are  hoiiiul  tou'i'ther  V)y  a  weh  of  coinj.lfx  relations.      1 
shall   li.T.MMfr  have  o<-<M-ion   to  show  that  the  «xotic 
l/.l.«'lia  nile-'-ii^,  in  th  -.  i.;ii  t  of  KM^'lall<^,  is  tuner  visited 
hy  insert-,  and  conseftueiitly,  from  its  pe.iiliar  strnrtiire, 
Mfv.r  can  set  a  seed.      .Many  of  our  orrhuhKeons  plants 
al.M.liitelv  r.'.|iiir.'  tlui  visits  of  mothn  to  remove  their 
i,olleii-ma»es  and  thus  to  fertilise  tliem.      1  have,  also, 
reason  to  I.elieve  that  hiimhle-hees  are  indi-|'ens.khle  to 
tlie  ferlili-.ition  of  the  he.irtsea>e  0  i<da  tricolor),  for 
other  hee-.  do  not  visit  tins  riower.      From  experimeiits 
whi.-h  1  have  lately  tried.  1   have  found  that  the  visits 
of  hees  are  necessary  for  the  ferlilisati(»n  of  some  kinds 
of  clover  ;  hut  hunihle-hees  alone  visit  the  red  clover 
(Triftdium   pratense),  as  other   hees  cainiot  reach  the 
nectar.      Hence  I    have  very   little  douht,  that  if  the 
whole  trenus  of  huml)le-l>ees   Itecame  extinct  or  very 
rare  in  Kntrland,  the  heartsease  ami  red  clover  would 
become  very  rare,  or  wholly  «li«ippear.      The  number 
of  humhle-'hees    in    any   district   dei»end9    in   a   jrreat 
de:rree  on   the   number   of  tield-mice,    which   destroy 
their  comhs  and  nests;  and  Mr.  H.  Newman,  who  ha» 
lonjf  atteiKled  to  the  habits  of  humble-bees,  Wlieves 
that  '  more  than  two-thirds  of  them  are  thus  destroyed 
all  over  Kn;:land.'     Now  the  numl»er  of  mice  is  larjfely 
d<'i>endent,  as  every  one  knows,  on  the  numl)er  of  cats  ; 
and  .Mr.  .Newman  iays,  '  Near  vilhitfes  and  small  towus 
1  have  found  the  nests  of  humble-bees  more  numerous 
than  elsewhere,   which   I  attribute  to  the   numl>er  of 
cats  that  destroy  the  mice.'     Hence  it  is  (juite  credible 
that  the  presem'-o  of  a  feline  animal  in  lartre  numbers 
in  a  district  mijrht  determine,  throuirh  the  intervention 
first  of  mice  and  then  of  bees,  the  fre.iiiency  of  certain 
flowers  in  that  district  !  ^  i  --i - 

In  the  case  of  every  species,  iii.tny  dirforent  ciiCcks, 
actinir  at  different  periods  of  life,  and  durinjr  different 
Hea»^aus  or  years,  probably  come  into  play  ;  Bt)me  one 


STIU  (K;LK    FOFt    K\l.sTKN(  K 


fi9 


iifi  k  or  Home  few  \>**:uu  uvuemlly  'lie  irio-t  p.itrnt, 
Imt  all  nmrur  iii  <lt't»'rmiMinif  the  avrraire  inirMlxT  or 
even  the  ••xi^'teiirc  of  tlie  sj,«Mij«<4  |ti  some  ra-e**  it 
..in  Im  sliowii  tli;»t  » idelv-dirT'Tctit  .•lie>'ks  art  on  llie 
-ame  Hpecie-*  in  i!itfi>reiit  distri"^*.  V\  liffi  we  look  at 
liif  plants  ami  lni!*lie>«  clMtlinii.'  an  entanirlfl  t>,-ink,  we 
are  tempted  to  attrilmte  their  proportional  miniU»r«*  and 
Kinds  to  what  we  call  chaiue.  Kiit  how  fal-e  a  view 
-  Mils  I  Kverv  one  ha-i  heard  that  when  an  American 
torent  \h  cut  down,  a  very  differeTit  veiretation  »'pnnf^ 
lip  ;  hut  it  has  hven  oiiierved  that  ain  ent  Iiuiian  ruin* 
;n  the  Southern  I  nited  Stages,  which  niiint  formerly 
have  heen  cleared  of  trees,  now  di^Jjdav  the  -.ame 
lieautiful  diversity  and  proportion  of  kirn'-  as  in  the 
>urroundintr  virL'ni  fore>;ts.  V\  liat  a  «truu„'le  U'tween 
tlie  several  kinds  of  tre«'s  must  here  have  jrono  on 
liiirintf  loritr  eenluries,  eadi  annually  scatteriinf  iti 
s»'cds  hv  tiie  thousand  ;  what  war  hetween  ni«-ect  and 
mseet  — hetween  insects,  snails,  and  other  animals  with 
l)ir>la  and  beasts  of  prey-all  strivintr  to  increase,  and 
all  feeding  on  each  other  or  on  the  tree-  or  their  seeds 
and  «eedlinirs,  or  on  the  other  plants  whi'K  first  clothed 
the  irround  and  thus  che<-ked  the  trrnwth  «>r  the  trees  ! 
riirow  up  a  handtul  of  feathers,  and  all  must  fall  to 
tli"  ground  accordinjf  to  detinite  laws  ;  hut  how  •simple 
i>  this  prohh'm  compared  to  the  a<'ti(»ri  and  redaction 
(if  the  iruuimerahie  plants  and  animals  which  have 
i<''erniiued,  in  the  cours**  of  centuries,  the  projtor- 
t.Dnal  niimhers  and  kinds  of  trees  now  uTOwinir  <>'i  the 
idd  Indian  ruins  I 

The  dependency  of  one  oriranic  heintr  on  another,  as 
of  a  parasite  on  its  prey,  lies  trenerally  heiwecn  Keinp? 
■emote  in  the  scale  of  nature.  This  is  ortcn  the  case 
•tit})  tlio'ie  wliich  may  strictiv  he  said  to  strutrtrl*'  with 
.ifh  other  for  existence,  at*  in  the  case  of  hMUSts  and 
jTx-s- feeding  quadrupeds.  But  the  >Jtrut:.'le  almost 
:i\  iriahlv  will  he  mo<t  .severe  hetween  the  individuaU 

■     1  '  .■       . )    -       i- ^  -  i  *  I —     -._-..,  .1 ;    *  _;  ^A^ 

/T   tiiti  Same  !i{iiH'i«'S.  i!".rirH.'y  irutjU!";;   ;i:f  :.a:i:;- :;;-•.;  :-._l», 

re   Hire  the  s.-irr,e  food,   and  are  expo^^ed   to  the  same 
iaiitjers.      in  the  case  of  varieties  of  the  same  specie*, 


70 


ON   THE   ORIGIN   OF  SPECIES 


« 


the  stnitf^le  will  p;enerany  he  almost  equally  severe, 
and  wo  snmetiTnes  see  the  contefit  soon  decided  :  tor 
instance,  if  severnl  varietit.-s  ofwlicat  he  sown  toffethpr, 
and  the  mixed  seed  1>»'  resown,  sme  of  the  varieties' 
whirl)  lif^t  suit  the  '■oil  or  climate,  or  are  nanirally  the 
tn'»-«t  fertile,  will  heat  tlie  others  and  so  yield  more 
seeil.  and  conseiiiuMitly  in  a  few  years  (juite  "tipplajit 
the  otlier  varieties.  To  keep  up  a  mixed  stock  of  even 
such  p.vtreniely  close  varieties  as  the  variously  coloured 
8wef't-j)eav,  tiiey  must  he  each  year  harvested  sej)arately, 
and  tlie  see'l  then  mix«-ii  in  rliie  proportion,  otherwise 
the  weaker  kinds  will  steadily  decrease  in  numbers 
and  disappear  So  airain  witli  the  varieties  of  sheep  : 
it  lias  }i('«Mi  as.serted  that  certain  mouutiin- varieties 
will  starve  out  oilier  mountain-varieties,  so  that  they 
cai.iiol  l>e  kept  "opether.  The  same  result  has 
fnl  lowed  from  licepinfT  totretl.er  ditFerent  varieties  of  the 
ni»'diriiial  loc.  li.  It  may  even  he  doubted  whether  the 
varieties  4)f  ativ  one  of  our  domestic  plants  or  animals 
have  so  exactly  the  same  strenarth,  habits,  and  con- 
stitution, that  the  oritrinal  proportions  of  a  mixed 
stock  idiiid  be  k(  pt  up  for  hali-a-<iozen  generations,  if 
they  were  allowed  to  strujr^rlo  to>rether,  like  l)ein^'-s  in  a 
stite  of  nature,  and  if  the  seed  or  younj^  were  not 
annually  sorted. 

.•\«  species  >f  the  same  ?renus  have  usually,  though 
by  no  me^iiS  invariably,  some  similarity  in  habits  and 
con^titutioT!,  and  always  in  structure,  the  strufffirle  will 
trenerally  be  more  severe  between  sj»e(ies  of  the 
^ame  eenus,  >*hen  thev  come  into  comjtetition  with 
lacli  other,  than  iietween  species  of  distinct  genera. 
We  see  this  in  the  recent  extension  over  parts  or  the 
L'niteii  St.'ite«  of  oi^e  species  of  swallow  having  caused 
the  decre.i.-e  of  Hfiot  her  --pecies.  llie  receiM  increase  of 
the  mihsel-tiirusli  in  parts  of  ><()lland  liap  caused  the 
decrease  of  the  sontr-thnish.  I  low  freji.ently  we  hear 
(»f  cue  species  of  rat  taking-  the  place  of  another  species 
uuuer  iie  mosl  uiiierj-iu  riimaieH  .'  in  Kussia  iiie 
•mall  .Asiatic  cockroach  has  evervwhere  diiven  t>efor»^  it 
ita  jfr'^i!  .  ontr^ner.      One  speeie'j  nt  j^i.ir!?*  1'    tuI 


•l  j>- 


STRUGGLE   FOR    EXISTEN' 


TT 


plant  another,  and  so  in  other  cases.  ^\  .  n  dimly 
M^e  whv  the  competition  should  be  inost  se.  t*rv  between 
allied  1  irms,  which  fill  nearly  the  same  place  in  tlie 
i-conomy  of  nature  ;  hut  probably  in  no  one  case  could 
*e  precisely  sav  why  one  sjiecies  has  been  victorious 
over  another  in  tbe  great  battle  of  life. 

A  corollary  of  the  hijrhest  importance  may  \>e  de- 
duced from  the  foreiroiiiir  remarks,  namely,  that  the 
structure  of  every  ortranic  beit;.c  is  related,  in  tbe  most 
e«5sential  yet  often  hidden  manner,  to  that  of  all  other 
.irtranic  beings,  with  which  it  comes  into  competition 
tor  food  or  residence,  or  from  which  it  ha.s  to  escape,  or 
on  which  it  preyn.  l'h\<  is  obvious  in  the  structure  of 
the  teeth  and  talons  of  the  tip:er  ;  and  in  that  of  the 
iejrs  ?.n(i  idjivvs  of  the  parasite  which  clinifs  to  the  hair 
on  the  timer's  body.  But  in  the  beautifully  plumed  seed 
of  the  dandelion,  and  in  the  flattened  and  frintred  U"j;s 
of  the  water-beetle,  the  relation  seems  at  first  confii.ed 
to  the  elements  of  air  and  water.  Yet  the  advantaije 
of  plumed  seeds  no  doubt  stands  in  the  closest  re- 
lation to  the  land  being'  already  thickly  clothed  by  other 
plants  ;  so  that  the  seeds  may  be  widely  distributed  and 
fall  on  unoccupied  pround.  In  the  water-beetle,  the 
structure  of  its  letrs,  «o  well  adapted  for  divinff,  allows 
it  to  compete  with  other  aijuatic  insects,  to  hunt  for  its 
own  prey,  and  to  escape  serving  as  prey  to  other  animals. 

Ihe  store  of  nutriment  laid  up  within  the  seeds  of 
many  plants  seems  at  lirst  sight  to  have  no  sort  of 
relation  to  other  plants.  But  from  the  strong  growth 
of  young  plants  produced  from  such  seeds  (as  peas 
uid  beans),  when  sown  in  the  midst  of  long  grass,  I 
■iu-pect  that  the  chief  use  of  the  nutriment  in  the  see«l  is 
t"  favour  tho  growth  of  the  young  seedlintr.  w  liilst  strug- 
ir'-.um  with  other  plants  growing  vigorously  all  around. 

l>)ok  at  n  plant  in  the  niiiist  of  its  range,  vvhy  does 
'*  not  douide  or  (luadrwple  itfi  numbers?  W'e  know 
'.;iat  it  can  jterfectlv  >oll  withstand  a  little  more  li.jat 

■I    V  Oiu,    UitiiiTiue.-v^    VII     uivi"ies:>,     lOT   Ci.sCWncrC    iv    iciii^CS 

!to  slifi'htlv  butter  or  cnlder,  damper  or  drier  districts. 
li   ihis  case  *'«  <'aii  clearly  see  *hat  if  we  wished  in 


72 


ON  THE   ORKilN   OF  SPECIES 


imaLniintion  to  irivo  tlio  iilaiilllio  power  of  iiicreasine:  in 
number,  we  slioiild  liave  to  ^nv»»  it  >nme  advant.itro  over 
its  cdniix'titors,  or  over  tlu'  aiiinial>  which  preyt-d  on  it. 
(  )m  the  cell  111  It's  of  its  t^vnu-rapliical  raiiire.  a  cliaiiire  of 
constitntKiii  witli  respfct  to  ciutiat»>  .Miuld  cloarly  he  an 
a(lvant:i:ic  to  our  phiiit  :  l)iit  we  have  reason  to  helie.e 
that  only  a  tew  platit-or  animals  ranire  so  far.  that  tlsey 
are  ilestroyed  hy  the  riL-'oiir  of  the  rliiuate  ah)ne.  Not 
until  wo  rea«'ii  tlie  extreme  confines  of  life,  in  th« 
Arctic  rcL'-ions  or  on  the  horders  of  an  utter  desert,  will 
competition  cease.  'Hie  land  may  he  extremely  cold  or 
dry,  y»'t  there  will  he  competition  between  >.oine  few 
species,  or  J>etween  the  individuals  of  the  same  species, 
for  the  warmest  or  dami)est  spots. 

Hence,  also,  we  can  see  that  when  a  jdant  or  animal 
is  placed  in  a  new  country  amon^r-t  new  competitors, 
tliouirh  the  climate  may  he  exactly  the  same  as  in 
its  former  home,  yet  the  comiitions  of  its  life  will 
g-eiierally  he  ch;ir.(red  in  an  essential  manne-.  If  wo 
wi--}ied  to  increa-  its  averatre  nu'nhers  in  its  new  home, 
we  should  have  to  modify  it  in  a  ditferent  way  to  what 
we  <lioii!d  have  done  in  its  native  country  ;  for  we 
should  have  to  trive  it  some  advauta^re  if.  er  a  dirferent 
sot  of  com|>etilors  or  enemies. 

It  is  srood  thus  to  try  m  our  imajjination  to  irive  any 
form  some  advantaire  over  another.  I'roiraidy  in  no 
siiitrle  iiiNtance  should  we  know  whai  t<.  do.  so  as  to 
succeed.  It  will  convince  us  of  our  ij^norunce  on  tt'e 
mutual  relations  of  all  oriranic  ifiiiirs  ;  a  .-oiiviction  as 
necessarv.  as  it  seems  to  he  diilicult  tr)  aiijiiire.  .Vll 
that  we  can  do,  is  to  keep  ste.tUily  in  mi;  d  that  each 
or;ranic  lieintr  is  striviiiL--  to  increase  at  a  tri'<nnetrical 
r.itio  ;  that  each  at  atune  period  of  its  life,  duriiiff  some 
e;>s(»n  of  the  vear.  durintr  each  L'i'neration  or  at 
intervals,  h.as  to  stru;:ule  for  life,  and  to  surier  ^reat 
destruction.  \\  hen  we  reflect  on  this  strutrLHe,  we  may 
conscde  ourselves  with  the  full  belief,  that  the  war  ot 
oatuie  i"«  (Mil.  iii,  »-*"*iiijl.  Tuitt  iiO  tCar  :■'  ::■;■.,  .;:.l;  iiJ'.;:-u 
ifj  treiierillv  jirompt.  and  tliatthe  vinnrous,  the  healthy, 
ar-d  the  happy  survive  and  muitijiiy. 


CHAPTKri    IV 


NATURAL    SELECTION 


N»tur»l  Selection  —  lU  power  conipartil  with  mans  nelectl 'n  -  Ita 
power  on  oharactfrs  "f  trifling  itnii'itmcc-  iu  p<iwer  »t  all  a<fw 
and  on  both  sexes  Sexual  S»-lecti"ii-  on  Die  Rfntralitj  i.(  lnt«r 
cr'isne*  l)etwfen  iiniivi'liiaU  of  the  same  six>i-ie»_i.lrcnnigtaiife« 
favourable  ami  unfavourable  t»  Natural  Self  tiori,  naniel>,  Inter- 
i;rossinK,  iBolatl'Ti.  number  of  in<livi(lual»-  Slow  a<lion  — F.itlnc- 
tlon  (ause<l  bv  Natural  Selection— Kiverir-'iice  of  C'barai-t*r, 
relat«.l  to  the  diversity  of  inhabltanU  of  any  ginall  area,  ao>l  t.-> 
uaturalisatioii  Action  of  Natural  Seleitiou,  thr^  ugh  liiverKence 
of  Character  and  V.xtiiii  ti'n,  on  the  descei,clai;ts  from  a  common 
paren^-Exp^ain8  the  Grouiiing  of  all  org-inic  beluga. 

How  will  the  strujrtrle  for  fxisteiK-e,  discussed  too 
brietly  ill  the  last  chaptor.  act  in  rei'-:ird  to  variation? 

aTi  the  [)riiuMj)le  of  soleilion,  which  we  have  seen  is  m> 
[totent  in  tin;  hands  of  man.  apjdy  in  nature  ?  I  think 
AP  shall  see  that  it  can  act  most  elTectually.  I>et  it  \>e 
*iorne  in  muid  in  whit  an  endloss  number  of  straii;,^e 
IM'cuitarities  our  dome.s'tic  producLions,  and,  in  a  lc-ss<;r 
(ii-^rree,  those  under  nature,  vary  ;  and  how  t.tron^''  the 
'icreditary  tendency  is.      I'nder  donu'stication,   it   may 

■0  truly  naid  tliat  the  whole  oriranisatiun  hec dme-.  m 
-ome  degree  j)la>tic.       liOt  it   he   horno  m   mind   how 

nfiiiitely  coniiilex  and  close-fitting  are  tlie  mutual 
relations  of  ail  ortranic  heiiiys  to  each  other  .intl  to 
'heir  physical  conditions    of    life.      Can    it,    then,   be 

linuirht  improhable,  seein^j  that  variations  useful  to 
man  have  undoutiiedly  occurre.i,  that  other  variationi 

'i^fiui  ill  non"ic  "<Vi»v  to  irac'ii  liaiiii  m  t-nv  &•■";.%«».  a.isi  !,;!Ui- 

;ilex  battle  of  lite,  sl>r»uld  sometimes  occur  in  the  course 
of  thousands  of  gener;ttions  }     If  such  do  <M:cur,  can  we 

7o 


^.ti 


74 


ON  THE   ORIGIN   OF  SPECIES 


r 


doubt  (remembeririff  that  many  more  individuals  are 
bom  than  can  possibly  survive)  tliat  individuals  havinvr 
any  advaritaffe,  however  slig'ht,  over  others,  would  liave 
the  best  «;liaiice  of  surviving  and  of  procreating  their 
kind?  On  tlie  otlier  hand,  we  may  feel  sure  that  any 
variation  mi  the  least  de^ee  injuriouy  would  l»e  rigidly 
destroye<l.  This  {(reservation  of  lavourable  variatioiiH 
and  the  rejection  of  injurious  variations,  I  call  Natural 
Selection.  Variations  neither  useful  nor  injurious 
would  not  be  fiffected  by  natural  seie<-tion,  and  would 
l>o  left  a  fhK'tuatinj;  elenu'iit,  as  pcriiaj)-  vve  -;t'e  iu  the 
B)>ei-ies  called  jiolyinorpbic, 

\\'e  shall  best  uiidt-rstand  the  probable  course  of 
natural  selection  iij  takiu;:  the  case  *it  a  <;ou!itry  undor- 
irointr  some  physical  chanjTc,  for  instance,  of  climate. 
Tlie  proportional  numliors  of  its  inhahitantf  vrould 
almost  immediately  umicrro  a  chantre,  aiid  some  i«j)ecies 
miffht  l(ec«»me  extinct.  ^\'c  may  conclude,  frotn  what 
we  h.ive  seen  of  the  intimate  and  complex  manner  in 
wliic;  the  inhab  Unts  of  each  country  are  bound  i(>- 
^ether,  that  any  chaiiife  in  the  numerical  proportions  <if 
some  of  the  inhabitants,  inrle[)endently  of  the  chan^-^e 
of  climate  itself,  would  seriously  affect  many  of  the 
others.  If  the  country  vere  oj)en  on  its  borders,  new 
forms  would  <'ertainly  immig-rate,  and  this  also  would 
seriously  disturb  the  relations  of  some  of  the  former 
inhabiiants.  Let  it  be  remembered  how  powerful  the 
iiiriuence  of  a  sino^le  introduced  tree  or  mammal  has 
been  sliown  to  Ik>.  But  in  the  case  of  an  islan.' ,  or  of  a 
country  partly  surrounded  by  b.irriers,  uito  which  new 
and  better  adapted  forms  could  not  freely  enter,  we 
should  then  h.-ive  places  in  the  economy  ttf  niture  which 
wfoild  ;issure<ily  be  br'tcr  tilled  up,  if  some  of  the 
oritrin;)!  iiihahitiints  '.v^re  iu  some  manner  modified  : 
fof-,  lia(j  tlie  area  ;)een  open  to  immiirraiio.'i,  these  .>,ame 
places  would  liave  been  seized  on  by  intruders.  In  such 
case,  every  sJiL'^ht  modirication,  which  in  the  course  of 
a4fes  >-ijaiuo«i  io  ir.sH.  and  whicii  iu  any  way  favoured 
the  individu.ils  oi  any  of  tiie  species,  by  lietter  adap-tin^ 
tht-tn  to  their  alteretl  ('••>nditiori«.  would  tend  to  be  pre- 


NATL'RAL   SELECTION 


75 


] 


served  ;  and  natural  selection  would  thus  ?jave  tree  si  ope 
for  the  work  of  improvement. 

U'e  have  re;i-on  to  believe,  as  stated  in  the  first 
chapter,  that  a  chanfre  in  the  condition.-  of  lite,  hy 
specially  acting  on  the  reproductive  system,  cause's  or 
increases  variability;  and  in  the  forec'np  ra^e  tlie 
contUtions  of  life  are  9Up{)osed  to  liave  uriderfrcii"-  n 
change,  and  tliis  would  manifestly  be  favourabi.  to 
natural  selection,  by  tfiviu^r  a  l>etter  chance  of  protit.il.ie 
vari,itious  occurriiifr ;  and  unless  profiUhle  variations  do 
occur,  natural  selection  can  do  nothinff.  \ot  'hat,  as  J 
believe,  any  extreme  amount  of  variability  -  necessarv  ; 
as  man  can  certainly  produce  ^eat  resuita  by  add;  ^ 
up  in  any  given  direction  mere  in''ividual  ditferemes, 
so  could  Nature,  but  far  more  easily,  rom  havi  iriiwom- 
i-rirauly  loiiiirer  time  at  her  di^^posal  Nor  io  1  believe 
lliat  any  trre.it  physical  rhanii-e,  as  of  climate,  or  ariv 
unusual  de-r.-ee  of  isolation  to  (heck  immiernttioii.  i« 
acraall>  riocessary  to  produce  new  and  unoccupied 
plaije*^  for  natural  selection  to  til]  up  by  modifying 
and  improTHig-  some  of  the  varying  inhabitants.  For 
as  ail  the  inhabitants  of  each  country  are  struir^rlins^ 
tOirether  with  nicely  balanced  forces,  extremely  ^li^ht 
moditications  in  the  structure  or  habits  of  one  in- 
habitant would  often  cive  it  an  advant-i^e  over  others  ; 
and  .^till  further  m(>diticati(»ns  of  the  same  kind  vvould 
orteu  still  further  increase  the  advantage.  No  count.'-v 
■  an  1)6  named  in  which  all  the  native  inhabitants  ue 
now  so  perfectly  adapted  to  each  other  and  to  th(> 
i>hysical  coniiitions  under  which  they  live,  that  none  ot 
thoin  could  anyhow  be  improve<i  ;  for  in  all  countrit>, 
tie  natives  have  been  so  far  con()uered  bv  naturalised 
proiiuctions,  that  the\  b.ave  nliowcd  forcij^ner?  to  lake 
irtn  posses,sioii  of  the  land.  And  a.-  forei^fnerH  ha%-e 
Lhus  everywhere  beaten  some  of  the  natives,  we  may 
saiily  conclude  that  tlie  !!i»tives  mi^nt  liave  been  inodi- 
tied  V.  ith  advantage,  so  hs  to  \!-:\'\  better  resisted  su*-)! 
viiLruders. 

.\s  man   can  produce  and  certainly  has  produced  a 
jfieat  result  by  his  methodirn'   snd   unconscious  meatis 


:r, 


ON    rHE    OKUilN    OK   SI'Kf'IES 


of  «elpcti()ii .  whrit  m.iy  not  Nnture  et?Vct  r     M:\n  rait  .tct 
only  on  px'rnial  ;in(l  visible  cliiracters  :   Nature  cares 
pot'hiiitr  for  ;i|'i'earances,  except  in  ■^o  far  -is  tlu'v  m.iy 
he  useful   to  any  beintr.      Slie  can  act  on  every  internal 
or:ran,  .m  every  shade  of  constitutional  ditference.  on  tlie 
whole  roa<hinHry  of  life.      Man  selects  onh  tt.r  his  own 
ffoofl;  Nature  only  for  that  of  the  beinir  which  -.he  tciMls. 
Kvery  selecte<i  character  is  fully  exercised  hy  her  ;  and 
the  heiriiT  '>  placed  under  well-suited  contlitions  of  life. 
.Man  keeps  the  natives  of  many  climates  in  the  same 
country  ;  he  >-old<>m  exercises  each  selected  character 
in  some  pecijiinr  and  fittintr  manner;  he  feeds  a  long 
and  a  short  beaked   pi{feon  on  tlie  same  food  ;  lie  does 
not  exercise  a  iotiir-hacked  or  lone-iegffed  quadruped  in 
any  peculiar  manner  :  he  exposes  sheep  with   lotie  and 
short  wool  to  the  same  climate.      F^e  does  not  allow  the 
most  viiforoua  males  to  strutrsrle  for  the  females.      He 
does  not  rigidly  destroy  all  inferior  animals,  hut  protects 
durinj;  eacli  varying  season,  as  tar  as  lies  in  his  power, 
all  his  productions.      He  often  heirins  his  selection  by 
some  half  Tr.'instrous  form  ;  or  at  le^st  hy  some  modifi- 
cation proi.niieutenoutrh  to  catch  his  eve,or  to  he  plainly 
useful  to  him.      I  iider  nature,  the  siiirhtest  ditference 
of  structure  or  constititioit   may  well   turn  the  nicely- 
halanced  scale  in  the  struirtrle  for  life,  and  so  he  pre- 
served.    Mow  tleetinjr  are  the  wishes  and  etTorts  of  man  I 
!iow  short  his  time  I  and   conseijuently   how  poor  will 
his  products  be,  compared  witli   t'loso  accumulated   hy 
.Nature  duriiiir  wl.oie  i/eolotrical  periods.    (  an  we  wonder, 
then,  that   Nat:ire's  productions  should   he  far  'truer' 
iii  character  tlKin  man's  pro<iuctions  ;  that  they  should 
i.e  intiii'f'lv  •  ctter  adapted  tf>  tht'  most  complex  condi- 
tions of  life,  and  shoubl  plainly  hear  tht-  slatnp  of  far 
bi-rher  workmansliip  .■" 


It  mav  TiietAph'Ticn 


riv1es:iid   that  natural  sele*  tion 


io  dailv  itid  hourly  scrutmisinir,  throutrhout  the  world, 
everv  variation,  even  the  sliffhtest ;  rejecting:  that  which 
is  had,  preservintj  and  adding  up  ail  that  is  good: 
gilentlyand  insensibly  workinjj,  whenever  and  wherever 
opportunity  offers,  at  the  improvement  of  each  organic 


I  i 


NATURAL    SELECTION 


77 


beiup  in  relation  to  its  ortranic  and  inorganic  condi- 
tions of  life.  We  see  notliiiitf  of  these  slow  rijanjres  in 
progress,  until  the  liand  of  time  has  niarkt'd  tlie  lotij; 
lapse  of  a^es,  arul  then  so  iinperftrt  is  our  view  into 
ioiii;  past  tfeoloifical  ajjes,  tliat  we  only  see  that  the 
forms  of  lite  are  now  tiitiercnt  from  v\  hat  they  formerly 
were. 

Although  natural  selection  can  act  only  tliromj-h  and 
for  the  ff^)^)H  of  euch  heiiij;,  yet  cliaracters  ami  >triictures, 
which  wo  are  apt  to  consider  as  of  very  trillin:.'-  im|»ort- 
c'ince,  may  thus  he  acted  on.  \\  lien  we  see  leaf-e^tinir 
in>ecta  green,  and  bark-feeders  mottled -yrey ;  the 
alpine  ptarmi<:an  white  in  winter,  the  red-t-Touse  the 
colour  of  heather,  and  the  hiack-irrouse  that  of  peaty 
earth,  we  must  believe  that  these  tints  are  of  service  to 
these  birds  and  insects  in  preserving  them  tVom  danjrer. 
Grouse,  if  not  destroyed  at  some  period  of  their  lives, 
would  increase  in  countless  numbers  ;  tlu'v  are  known 
to  suffer  lartrely  from  birds  uf  prey  ;  and  hawks  are 
guided  by  eyesight  to  their  prey — so  much  so,  that  on 
parts  of  the  (.  ontinent  persons  are  warned  not  to  keep 
white  pigeons,  as  being  the  most  liable  to  destruction. 
Hence  1  can  see  no  rcison  to  doubt  tliat  natural  selec- 
tit)n  might  be  most  effective  in  giving  the  proper  colouf 
to  each  kind  of  grouse,  and  in  keejdng  that  colour, 
when  once  acijuired,  true  and  constant.  Nor  outriit  we 
to  think  that  the  occasional  destruction  of  an  animal  of 
any  narticular  colour  would  produce  little  etfei't :  we 
should  remember  how  essential  it  is  in  a  flock  of  white 
slieep  to  destroy  every  laml)  with  the  faintest  trace  of 
black.  In  plants  the  down  on  the  fruit  and  the  colour 
of  the  flesh  are  considered  by  l)0tanistj?  as  characters  of 
the  most  trifling  im{X)rtance  :  yet  we  hear  from  an 
excellent  horticulturist,  Downiruf,  that  in  the  Iriited 
States  smooth-skinned  fruits  sutler  far  mure  from  v. 
beetle,  a  curculio,  than  iho.se  witli  down  ;  tiiat  puqile 
j)lums  sutler  far  more  from  a  certain  disease  tlian  yellow 
piuins  ;  will  reas  auuLiier  ili^e.ise  aUA«  k-*  yeiidw-iiesiied 
jieaches  far  more  than  those  with  other  coloured  flesh. 
if,  with  all  the  a-ds  of  art,  tbet<e  sliirht  differences  make 


78 


ON   THE   ORIGIN   OF  SPECIES 


I  jfrft.it  differouce  in  cultivating  the  several  varieties, 
i.-wuredly,  in  a  state  of  nature,  where  the  trees  would 
have  to  etruffjfle  with  other  trees  and  with  a  host  of 
oneiniew,  such  differences  would  etfectually  settle  wliirh 
variety,  whether  a  smooth  or  downy,  a  yellow  or  purple 
fleshed  fruit,  should  succeed. 

Ill  lookiiier  at  many  small  points  of  difference  be- 
tween  species,  which,  as  far  as  our  ig^noraiice  permits 
us  to  judfje,  seem  (juite  unimportant,  we  must  not  forget 
that  climate,  food,  etc.,  probably  produce  some  slight 
and  direct  effect.  It  is,  however,  far  more  necensjiry 
to  bear  in  mind  that  there  are  many  unknown  laws  ot 
correlation  of  jfrowth,  which,  when  one  part  of  the 
or^^anisation  is  modified  throufj^h  rariation,  and  the 
modifications  are  accumulated  by  natural  selection  for 
the  good  of  tlie  bein^',  will  cause  other  modifications, 
often  of  the  most  unexpected  nature. 

As  we  see  that  those  variations  which  under  domesti- 
cation appear  at  any  particular  period  of  life,  tend  to 
reappear  in  the  offspring  at  the  same  period  ;  -for  in- 
stance, in  the  seeds  of  the  many  varieties  of  our  culinary 
and  aiiiricultural  plants  ;  in  the  caterpillar  and  cocoon 
stages  of  the  varieties  of  the  silkworm  ;  in  the  eg-jfs  of 
p(»ultry,  and  in  the  colour  of  the  down  of  their  chickens ; 
in  the  iiorns  of  our  sheep  and  cattle  when  nearly  adult ; — 
so  in  a  state  of  nature,  natural  selection  will  be  enabled 
to  act  on  and  modify  organic  beinps  at  any  a^e,  by  the 
accumulation  of  variations  profitable  at  tliat  aije.  and  by 
their  inlieritiince  at  a  correspondini;  aije.  If  it  profit  a 
plant  to  have  its  seeds  more  and  more  widely  dissemi- 
nated by  the  wind,  1  can  see  no  ^eater  difhculty  in  this 
beinif  etfected  throutrh  natural  selection,  than  in  the 
cotton-planter  increwising:  and  improvinjf  by  selection 
the  down  in  the  pods  on  his  cotton -trees.  Natural 
selection  mar  modify  and  adapt  the  larva  of  an  insect 
U)  a  score  of  contingencies,  wholly  different  from  tliose 
which  concern  the  mature  insect.  These  modifications 
will  no  doubt  alfect,  throujfh  the  laws  of  correlation,  the 
structure  ot  the  adult;  and  prof)uhly  in  the  c^se  of  those 
insects  which  live  only  for  a  few  hours,  and  which  never 


NATURAL  SELECTION 


79 


iee<\,  a  large  part  of  their  structure  is  merely  the  >  or- 
related  result  of  successive  changes  in  the  structure  of 
their  larvjr.  So,  conversely,  moditicatioi's  in  the  adult 
will  probably  often  affect  the  structure  of  the  larva ;  but 
in  all  csLnes  nat'iral  H»'k'ctioii  will  ensure  that  moditica- 
tioin  con8e<]uont  on  other  inodirtcations  at  a  different 
period  of  life,  shall  not  l)e  in  the  le<ist  degree  injurious: 
for  if  they  V)6came  so,  they  would  cau>e  the  extinction 
of  the  species. 

Natural  selection  will  modify  the  structure  of  the 
young  in  relation  to  the  parent,  and  of  the  parent  in 
relation  to  the  young.  In  social  animals  it  will  adapt 
the  structure  of  each  individual  for  tlie  benefit  of  the 
community;  ifftich  in  conse<juence  pnttits  l)y  the  selected 
change.  What  natural  selection  cannot  do,  is  to  modify 
the  structure  of  one  species,  witliout  giving  it  any  advan- 
tage, for  the  good  of  another  sj>ecies ;  and  tliough  state- 
ments to  this  etiect  may  be  found  in  works  of  natural 
history,  I  cannot  rtnd  one  case  which  will  bear  investi- 
gation. A  structure  used  only  once  in  an  animal's  whole 
life,  if  of  high  importance  to  it,  might  be  modified  to 
any  extent  by  natural  selection  ;  for  instance,  the  great 
jaws  possessed  by  certain  insects,  used  exclusively  for 
o}>oning  the  cocoon — or  the  hard  tip  to  the  beak  of 
nestliiv  birds,  used  for  breaking  the  egg.  It  has  been 
assertea,  that  of  the  best  short-beaked  tumbler-pi;.^'*^^ 
more  perish  in  the  egg  than  are  able  to  get  out  of  it ; 
so  that  fanciers  assist  in  the  act  of  hatching.  Now,  if 
nature  had  to  make  the  beak  of  a  full-grown  pigeon 
very  short  for  the  bird's  own  advantage,  the  process  of 
tnodincatiou  would  be  very  t^low,  and  there  would  be 
'simultaneously  the  most  ri^rorous  selection  of  tlie  young 
birds  within  the  egg,  which  had  the  most  powerful  and 
hardest  beaks,  for  all  with  «eak  l>eaks  would  iiu'vitably 
[)erish  :  or,  more  delicate  and  more  e;i-ily  broken  sliells 
might  be  selected,  the  thickness  of  the  shell  being  known 
to  vary  like  every  other  structure 

Sexual  Selection.  —  Inasmuch  as  peculiarities  often 
appear  under  domestication   in    one  sex  and   become 


tn  ON   THE   oRKilN    OK   SPECIES 

bereditarily  attaclied  to  that  sex,  the  «aine  fa.-t  prob- 
iii.lv  occurs  undor  nature,  and  if  so,  natural  selection 
will  he  aide  to  nK.dity  one  >ex  in  its  fun.-tional  rela- 
tions to  the  other  sex,  or  in  relation  to  wholly  dirterent 
hahits  of  life  in  the  two  sexes,  as  is  sometinieH  the  case 
with  inserts.      And  this  leads  me  to  say  a  few  words  on 
what  1  call   Sexual   Selection.      'Hii-*  depends,  not  on  a 
stni.-'le  for  existetiee,  hut  on  a  stru-L'le  hetween   the 
n.ale>  for  iM.ssession  of  the   females  ;   the   result  is  not 
death  to  the    uusuc.es>l!,l    ccwnpetit-.r,   hut   tew   or  no 
otlM.rintr.      Sexual  selection  is,  therefore,  less  riK'orous 
tlian  natural   selection,     (ienerally,  the  most  vi»forou9 
males  tho^e  which   are  hest   fitted   for  their  places  lu 
nature,  will  le^ve  most  pn.^reny.      li'it  ui  many  cases, 
victory  d.-pends  not  on  ireneral  vigour,  hut  on  havintr 
special  weapons,  confined  to  the  male  sex.      A  hornless 
stijr  or  spurless  cock   would   have   a  poor  chance  of 
leaviiiif  otfMirinir.      Sexual   selection  hy  always  allow- 
iua  the  victor  to  hree<l  miffht  surely  true  indomitiihle 
courage,  lenirth  to  the  spur,  and  stren-th  to  the  wnig 
to  strike  in  the  spurred  let:,  as  well  as  the  hruUil  co.-k- 
ft.rhter,  who  kiK.ws  well  that  he  can  improve  his  h reed 
bv  careful  selection  of  the  l)est  cocks.       How   low  in 
the  scale  of  nature  the  law  of  battle  descends,  I   know 
not;  male  allitfiitors  have  been  described  as  tij^htniff, 
bellowiims  and  whirlintr  round,  like  Indians  in  a  war- 
dance,  for  the  possession  of  the  females  ;  male  salmoius 
have  been  seen  tiKhtiiitf  all  <iay  loug  ;  male  statf-beetles 
often  hear  wounds  from  the  huKe  mandihles  of  other 
males      llie  war  is,  perliaps,  severest  between  the  malea 
of   polvL-amous  animals,  and  these  seem  ottenest  pro- 
vided With  special  weapons.     'Hie  males  of  carnivorous 
animals  arealre;uly  well  armed;  though  to  them  and  to 
others,  special  means  of  defence  may  be  -iven  through 
means  of  sexual  selection,  as  the  mane  to  tlie  lion,  tlie 
shoul.ler-p.id   to  the  hoar,  and   the  hooked  jaw  to  the 
male  salm.-n  :  for  the  shield  may  be  a^  imporUnt  for 
victory,  ;ui  the  sword  or  spear. 

Amon^rst  birds,  the  contest  is  oflen  of  a  more  peaceful 
character.      All  those  who  have  attended  to  the  subject, 


NATCRAL  SELKCTION 


81 


ttlnM.'  that  th»!rp  is  tlie  spvpn'xt  rivalry  hotwpen  the 
iii.iU's  of  niiiiy  «jK'cip-»  t(»  attrnrt  \i\  MJiiirint;  tli'*  fcniales. 

I  lit-  nick-tfirusti  (•<  (Jiii.ina,  hir'lsof  J'ararli^o,  and  some 
(itlnTs,  ron^/rt'tnte  :  ami  siicfcsHive  males  display  llipir 
/  •'•j.'f'oiiM  jiliiiii.i;.'0  .111(1  jierform  straiiLT  antic-s  ln-foro  fl-.e 
>fi'i.tl»>s,  wliicli,  Ktiimiiiii.'-  Iiy  a.s  sjn-rtators,  at  last  <-hoo>c 
'II-  iiio^t  ati  :Miiiv»»  jtartiMT.  'J  lio^e  who  havo  closply 
.iitfiidefl  to  tiirlx  in  rontiin'inorit  well  know  that  tlipv 
iili'ii  take  iiu!i\  i()iinl  jircfercnc*'-  and  dislikes:  tliiiri 
^:r  l(    Hcroi:   li  i-  d»'s«riU»d   Ijow  one  [dcil   jteacoi  k  was 

'niiifiiil .  attr.ictivt'  to  hII  hi.-  hen  hirds.  It  may 
appf.ir  <i,iidi-l;  to  attriliute  any  oth'ct   to  such  apjiar- 

'illy  wwik  iiuviiis  :  I  (■.•uiiiot  hrre  enter  on  tin?  details 
i.i'i-cssary  to  siijiport  this  view  ;  hut  if  man  can  in  a  short 
•■'Ml'  ^ivc  ele^'ant  ('arri.'ij.''i'  and  hcautv  to  his  hantams, 
.!•  cMrdii:^''  t'»  hi-  >-tand;ird  ot  he.iut}',  I  can  see  no  foed 
rci-ni,  lo  duiild  that  tcniale  hir<ls.  liy  selecting,  durinsj 
ttio  ,-'i!]ds  of  irencratioiiK,  tlio  mo»t  mclodiou.'^  or  heaii- 
rr;;!  inalc-.  aciordintr  to  their  t-t;iii(l.ini  of  l>e;i'ity, 
Ti).i;li'.  jTixIuce  ;i  marked  otfecf.  I  strontrly  sii'-jioct 
that  soiiie  well-known  laws,  with  respect  to  the  pluuiat'-'^ 
u(    Ilia!.-    and    female    hirds,    in    cnmpitrison    with    the 

II  iirn:i:.'e  ol  the  yoiiiiir,  can  he  e.xpiaiiied  'in  the  vietv 
ol  pli,m;i^'^e  hiNJiiir  !>eeii  chiefly  modified  hv  se.\ua! 
sclectioii.  actiiiLf  when  the  hinls  have  come  to  the 
!''it'ilin_'^  aire  or  diinntj  the  l)reediM!r  sea-on  ;  the 
r'liditic.'it'ons  thus  prt'diiced  heiiitr  inherited  at  corre- 
-pondiiii:  .'It! I  -  or  seasuns,  either  hy  the  males  alone,  or 
liv  l.e  rii.ileK  ,iiid  females;  but  1  ha\e  nut  sjiace  here 
to  enter  on  this  siiKjeet. 

liiiis  it  is.  as  1  hcl'eve,  that  « hen  the  males  and 
r''in;.lfs  of  any  animal  have  the  .s.ime  ^'eiieral  hahits 
•  '}  li.o,  hilt  ditier  in  structure,  colour,  or  ornainont, 
-'  1  ii  dirterences  have  heen  mainly  caused  hy  sevual 
>electi(m  ;  that  is,  individual  males  have  liad,  in 
-uccessive  ueneratiouh,  some  slitrht  advaiitatfo  over 
otfiiT  males,  in  their  weapons,  means  of  defence,  or 
<:«'ius;  and  have  transmitted  tfiese  advantages  to 
!. '.••!■  male  otlsprintr.  Vet,  J  would  not  wish  to  attri- 
bute all  such  sexual  differences  to  this  agency  :  for  we 


^* 


MICROCOPY    RESOLUTION    TEST    CHART 

AN5I  and  ISO  TEST  CHART  No    2 


1.0 


I.I 


1.25 


i:^  I  2.8 

1-  I-" 

2.5 
2.2 

1:  1^ 

2.0 
1.8 

1.4 

1.6 

J  APPLIED  IfWIGE 

r^S  'ochestef.   Me»   Yo'k         U609       US* 

=  ^ '  6)  ♦aj  -  0300  -  Phone 

^S:  716)   288  -  5989  -  Fo. 


inc 


'  '  1  ;  ; 


R2  ON    TUK   cRUilN    OF    S1'K(  lES 

-t>P  noculinrities  arisiiitr  and  hpconim- .itta,-hp<l  tn  th.? 
„.U-  M.x  i:.  o.r  .Inmestic  a..irr..ls  '..  ti.o  watMoin  male 
rarritT-..  Imrn-lik.'  i.r..tuWr.in'>>H  iii  tn.M-u,k>..t  certain 
fowU  ctr.),  whirh  ■^«>  ."iiHiot  iM.liove  to  I..-  citlier  u.otul 
tt,  tl„.  rual*..  in  hattV,  or  rittnu'tr...  to  tl.»'  femaie.. 
We  ^.'0  ruialoirous  .•;.>(-  uihI^t  tiatun-.  tor  instanre,  U-^ 
tuft  of  li.ur  on  iho  hnM,t  ..f  tl.o  turkoy-.o.k  wlnrh  ran 
i,ar<llv  ).o  .MtluT  us.'hil  or  ornru.uMitil  to  this  t.irU  ,  - 
,:al...-'.l,  l.a.l  th.'  tun  appo.ire.l  an. iff  domestiratioii,  it 
would  have  l.ecn  rallo«l  a  iTioii-tro-.ty. 

Uluxtrntious    <M    tn>-   "rtinn    oj    SntHrnl  S.b'rtum.-     \n 
order  to  muki'  .t  clear  how.  as  !   believe,  natural  selec- 
tion  arts,   I   mu^t    U-   i.ertn.ssion  to  ij.ve  one  or  two 
i„,au-..Kirv  ,llu>tratK,..s.      !..-t  us  fike  the  ca.e  o    a  wo    . 
whieh  pri'vs  on  various  animals,  se.-unni:  some  t.y  tratt, 
so:ne   I'v  ^ireuu'th,  and  so.no  hy  lleetness  ;  and   lot  us 
Mn,i...<e  th.a   the  Tu'etest  prey,  a  deer  t.,r  instance,  had 
fr.liM  anv  .-lian-e  m,  t!u,  country  iucraised  ui  luimbers, 
„r  that  other  prey  ha.l   decre.i^.ni   it.   tiuinhers,  durir« 
1,  it  smson  ..f  the" Near  when  the  wolf  is  hardest  presse<i 
t„r    food.       i    can    under    sueh    eircumstanres    see    no 
reason  to  dou!.t  that  the  swiftest  and  rtliinmest  wolvea 
,,.,,,1,1    ha^e   .ho   Lest  chance   of  surviviiur,  :'>"1   -^^^ 
pn..erve.l    or    -elected,  -  provi.led    always    that    they 
retained   .tretiL^th  to  master  their   prey  at   tins  or  at 
soTMO  other  peno.l   of  the   year,  when  they  mitrht  i>e 
'  '         -  - '         I    can   sec   no 


Miipelh 


♦  ,,    j>rey   on   other   aininals. 


,:H.ro  reason  to  ,!oul.t  this,  than  th.it  man  can  im- 
prove Mie  tleetne-s  o.  hi>  greyhounds  hy  caretul  and 
,r..th.Miical  selection,  or  hy  that  unconscious  •e.ection 
which  results  from  each  man  trying'  t<.  keep  the  bent 
d,.-.  witli.Hit  anv  tli.ni-ht  of  modifyine  the  breed. 

Kwn  without  anv. han-e  m  fh.-  proportional  numlwjrs 
of  the  animals  on  which  our  woU  preye.i,  a  cub  mi^ht 
■■,e  horn  vnth  an  innate  tendency  to  pursue  cerUm 
W.nds  of  nrev.  Nor  can  thi^  In?  thou;:ht  very  im- 
•,rohahle;  no-  we  ot\en  .d.serve  ureal  .iiner.-nce^  in  tha 
natural  ten.lencies  of  our  d.mie-tic  animais  ;  one  c^., 
tuT  uistan.e,  takin-  lo  .atch   racs,  another   mice;  or-s 


NATIHAI.    SKI  K»   rit.N 


a.3 


I 


fAt.  ar-nrdintf  to  Mr.  >t.  Joiitj,  hriii^rme  hfinif  winifed 
traii'e.  a"n>h«r  liare-*  or  rai»i»;i.-<,  ritui  ani.'iior  fiuiitiru  on 
riiarsliy  erouinl  and  almost  niijlitlv  i.-alrliintr  woiMlcM-kH 
or  vTiijics.  nit?  temieut-y  to  latch  raU  rather  tiiaii 
mice  is  knnwii  to  1)6  inliertttl.  Now.  if  aiiv  ^liifht 
iriiiate  cfiaiiKf*  ot  liabit  or  of  structure  l>o!.«ihteii  an 
individual  wolf,  it  would  (lave  the  best  ciiaiice  of 
xiirv  i\i;ii,'  and  of  leJivnii,'  ort.-.[(rniir.  Surnt*  nf  lit*  vouiijr 
wouhl  probably  inherit  the  same  hanit.s  or  Htructure, 
an<i  l>y  the  rrpotitiun  of  t)i.s  jiroce-^s,  a  v.f.v  variety  rniifht 
i>f»  rorijie<i  which  would  either  supplant  or  coexist  with 
tfie  jiarent  form  of  w(df.  ( )r,  a^riiin,  the  widves  ia- 
habitii.t:  a  mountainous  di-rrict.  ami  those  frcijut-ntiii^ 
the  lowlaii'ls,  would  naturally  be  forceil  ;o  hunt  di.Terent 
j.rey  ;  and  from  the  continued  preservation  of  the 
individuHls  !>est  fitted  for  the  tv*-o  site>,  two  varieties 
miirlit  slowly  !»e  formed.  riie>e  varieties  would  cro«« 
and  blend  where  tiiev  met  :  but  to  this  .subject  of 
interTossinjr  v*«' shall  soon  iia-.  e  to  return.  I  may  add, 
that,  accordinir  to  Mr.  Pierce,  there  are  two  varieties 
of  the  wolf  inhabitinjf  the  (  aLskill  Mountiiins  m  the 
''nite'l  States,  one  with  a  litfht  irrevhound  like  form, 
whicli  pursue^  deer,  and  the  other  more  iuilk-,,  with 
^ilorter  letrs,  v*birb  more  frei|uently  attiicks  the 
shfpherd  -  flocks. 

i.*'t  us  now  take  a  more  complex  case.  *  ertain 
phiots  excrete  a  sweet  juice,  apparently  for  ii.e  sake  ot 
eliminatiniT  ^;omethini»  injurious  from  their  s,-ip  :  ttiis  in 
etfected  by  trl^iid,-.  at  the  b.ise  of  the  btii'ules  in  -ome 
l>'_Miminos«*,  and  at  the  back  of  the  leaf  oJ  the  oriniion 
biurel.  Tliirt  juice,  tlu)u;,'h  -mall  in  -juantitv.  ih 
i-'rcedily  soutrht  by  insects  j^t  us  now  suppo-e  m 
little  sweet  juii  »•  or  nectar  to  be  excreted  by  the  inner 
!..-.(■-  of  the  (letals  of  a  •b)v*-er.  in  this  ca-e  i^st  <  tn  i;i 
seekiiijr  the  iH'i-tar  v*o!il(I  .-^et  ciu-tcd  with  jwdlen,  ami 
'Vol. 1(1  certainly  often  trans|nrt  tin-  poilen  from  one 
t!o'.<-er  to  tile  ft.irma  of  another  liower.  rheli<;wers  of 
iwo  distinct  ithiividuals  of  tlie  same  .■•peces  would  ttiuu 
ev-  crossed  ;  and  the  act  ot  cro-?-iinf,  we  ha»e  trood 
rBa#on    to    beiievp   (aa    will    hereafter    •<»•    niore    fully 


84 


ON    rilK   ORKilN    OF   SPKCIES 


allud»'<l  to),  wf>:;l(]  prociurp  \ory  vit'onius  Hee<lliii/v, 
wliK  li  roii'i'ijiH'iillv  uiiiild  liasc  the  \n-Mt  «'l:,i!ic«'  of 
floun^liiiitr  ami  surviving-.  >imif  ot  t)ip<e  ni'e«iiinir^ 
woulti    pri.liHl)!)'    HiluTit    tlic   lUM-Lir  -  ♦■xcr»'t!ii{f    power. 

or  iifi'tario'',  :iij<l  wni'  h  t*xrret»'ii  mu-!  nei  uir,  wdtil.l  lio 
often. -si  visited  by  iiihects,aiid  wmilil  l>e  (ilteiie-it  crossed  ; 
ami  ^^l  ill  t!i»'  liin;:-riiii  >Noiilii  tj.iiu  the  ui'j'er  hand. 
riu)-.e  ll(>u.'r^.,  ,•ll.•^(<.  Miiii'h  iiad  tlieir  iJtaiiifiis  and  pi-^tils 
pl.ieed ,  lii  ridaLion  to  llio  ^ize  and  t.aitit-  of  tlu* 
pari)'  ular  in!^f»:tti  whicli  visitt'd  tlieni,  •>(»  as  to  fasoiir 
in  Hin  detTet'  the  tran^portal  td"  liieir  imllen  from 
llower  to  fiu.MT,  would  likei*i-t'  i)e  favoured  or  •«elefte<i 
Wv  initriit  liavetaiseii  tlie  c.t.'^e  of  in--eets  viHitiritr  liov\er> 
fur  the  n.ike  of  coile<'Mnir  polien  in'-teaii  of  nect.ir  ;  and 
as  poi.eii  1-  t'lrnu'd  for  tiie  side  oii't-et  of  terhiis.ition, 
its  destruction  nppears  a  siriijde  i<i-»  to  tiie  plant  ;  yt-l 
if  a  lilllo  pollen  were  e.irriei',  at  !i;-t  ocea-;"r,ally  and 
then  iiaiiitu.illy,  hy  the  p(dleii-<ievourini£  ni-.t.,'t-  from 
IhivM-i  te  flower,  and  a  cro^s  thus  etn-eteti.  aithouifh 
tiine-te'iths  of  the  pollen  \M-r*'  <ie-tro\fd,  it  iii!L''ht  still 
i)e  a  areat  L'^ain  U>  tlie  id.ml  ;  ami  those  individuals 
whi<  h  prodt'ifd  mo'-e  an'  more  pollen,  \:\i\  had  lar^jor 
and  larger  anlhers,  wduld  he  seie.  teil. 

W  1  ei-  our  plant,  iv  this  p.-,„-(.^^  ot  the  .ontinued 
pre-iT'.  atinn  or  natural  selei'tion  of  more  aiid  iimre 
attr  i.'t;  .e  r''\*  ers,  (lmI  heeii  rendered  hi:,'h!v  attraeti^e 
to  iii-ieet'.  t!,ev  would.  unin(eiitioii.i!l\  on  their  jiart, 
rej.'ulari\  lari  \  puUeii  irom  liower  to  tlower  ;  ami  that 
tlie\  ean  ni<i>l  enectualiy  do  this.  I  could  easily  sho-v 
bv  many  strikiii::  instame^.  i  will  trive  onl\  one  -not 
ah  a  \t'rv  striking''  c;ise,  hut  as  likewise  iliusM.itinij  one 
gtei>  in  tiie  separat'oii  ui  tio-  sexes  of  plan'.s,  pre-eutly 
to  lie  alluded  to,  >(i!iie  htdiy-trei-'  near  i<  ily  niaie 
flowers,  whieh  i)a\e  tour  st.;iTnens  protim-inj  r  rather 
small  <jUintitv  of  pidieri,  and  a  rudimentary  pistil  ; 
other  hidiy-iries  jie.-ir  oiiK  feinalp  tlowers  :  t*ie>e  have 
a  full-si/.ed  pi-til,  ami  four  stamens  with  shruelled 
anthers,  in  whiih  not  a  triain  of  pollen  ean  he  (ieterted. 
Ha\'in^  tiuHid    n   lerM.uc  tree  exactly  siity  yard*  from  ? 


I 


NATCilAL   SEI.KCTION 


85 


male  trpo,  I  put  the  (itiffnias  of  twenty  riower»«,  taken 
from  ditferpnt  hraiirliPH,  (imior  the  microijoope,  and  on 
all,  without  eireption,  thcrp  were  pollen-urairiH.  and 
on  some  a  profuMon  of  polU'ii.  An  tiio  wind  liad  set 
for  several  liayn  from  the  female  to  the  male  tree,  the 
pclien  roiilil  not  tluiH  have  Ueen  carrieil.  The  woather 
li.-i'l  tieeii  colli  am!  'mi-itoroi.-i,  ami  therefore  liol  lavour- 
aldo  to  !i>'t'-<.  nevcrthele^h  evcrv  feni.ile  tlowt-r  which 
I  exannin'.l  had  been  etf^'ctually  fertili-''d  hy  Uif  hee«, 
acc-ideiit-ill V  d.istcd  with  pollen,  havimf  tiown  tVom 
tree  to  tree  in  search  of  n»;»t;tr.  Hut  to  return  to 
our  irii:t^riiiarv  "'a^e  ;  as  soon  as  the  plant  liad  U'en 
leiidered  so  hurhlv  attractive  to  injects  that  pi>ll»'n 
w.M  re;:\i!arlv  carr;t^l  from  ilower  to  ilower,  another 
pro'-tv-«  lutriit  commence.  No  naturalist  ilouht-t  the 
advanta^'-e  of  what  lias  heeri  i-allnd  t!io  '  phy«ioloiriral 
div!-i(ui  of  l.i'iour';  tienre  '■w>  may  heiie\e  that  it 
would  h»'  .ifiv-intaLO-ous  to  a  idant  to  proiiure  stamens 
ilone  in  me  llowt-r  or  <ui  one  w}iole  [•iant,  iinl  p'.^tiU 
^ioTle  'n  another  (lower  or  on  anotlu'r  ]ilaiit.  In  pianti 
under  culture  aiid  place<l  under  new  conditions  of  life, 
ioriietimci  th»'  nia't)  ortraijs  and  sonu'tinu'S  the  tetnale 
oitransj  heconie  more  or  less  irnjiMtetit  ;  n<m-  if  ^e 
sup{M)sc  this  to  (x;cur  in  ever  <-a  »li':ht  a  deirreo  under 
.'ii'ure,  then  a8  pollen  ia  already  carried  retruiarly 
fii'in  Mower  to  tlower,  an<l  as  a  more  coTiiplete  separa- 
tion of  the  Pexes  ot  our  plmt  would  he  a>lvanLaireous 
on  tlie  pni'.ciplo  of  the  division  of  lahour,  individual! 
with  ttii<  rciuiency  more  and  tnore  incre;i.-ed,  would  (>« 
continuallv  favoured  or  seiccU'd,  untd  at  lasi  a  com- 
plete separation  of  the  sexes  w(»uld  })e  effected. 

l>'t  U9  now  turn  to  the  nectar-feed iiiif  insect.^  m  our 
iinairi'' irv  <a.«e  :    we  mav  su[)po-o  the  plant  of  whieh 


se  ha'-e  hcen  -•'  >wly  incre.'.-'iiii:  the  nectar  hy  roritTiued 
select  ion,  to  le  a  common  plant  ;  in<l  tliat  certain 
lii-ectH  d^]MMided  in  maui  part  un  ita  r^ocLar  tor  food. 
!  could  ifive  many  fact.*;,  >howi!!tr  1m. w  anx'.ou.s  Wees  are 
to  s;ive  time  ;  for  in.-'anie.  tlieir  haliit  of  cutt'fu;  hole,s 
and  Kuckiiijf  the  iiecL;tr  at  the  lwi."-cs  of  wrtiiin  liowers, 
•viixli  they  can,  witli  ?  very  little  more  trouble,  entei 


i9^mm^m:mjf^^mm^mmm& 


-,v-- 


86 


ON    THE   OUKilN   OF   SPK(  IKS 


fji: 


by  the  mfhith.      Hcarinc  S'lidi   farts  in   rniii<l,  I  nm  ^pe 
no  reason  to  (loii).l  fiiat  ;in  a("ci.icnt;il   deviation  in  the 
nize   ,.M(]    trtriri    nf  tli,.    (.,„ly     or   it     the   curvature  ■-.iid 
length    of   the    prohos.is.  'ete. ,    tar    t<iO    s!ii:iit    tn    i„. 
apjire.iated   l.y   hh,  iniirh*   profit  a  heo  or  other  in-e.  t. 
BO  tliataii  in(i:\i.l:iai  vo  rharacterised  ur.-jhl   he  aide  it] 
ohtam    it<   food    moie   <)iiii'kly,   and    -o   fiav©   a    better 
chance  ol"  livi'ip  and  lea\  inj;  (Jeseen<lar;ts.     Jtj*  desi  end- 
ant.s   would   j.rohaldy  inlierit   a   tendenc-  to  a   similar 
sli^Iit  deviation  of  stnirture.     'Ilic  tiil.e.-'of  the  coroH.-a 
of  the  eoinrnori    red   and   inran;ale  cl-.ver*,  ('I'rifoliiim 
pratense  and    incarnatutn  i  do   not   on    a   h;isly  glance 
appear  to  diiFer  in  lentrth  ;   yet  the  Inve-hee  can  easily 
suck    the  nectar  out  of  t}i<'  incarnate  clover,   hut  not 
out   of   the   .•onimon    re<;    clover,    which    in   visited    l>v 
hurrddeiiee-    alone;    >o    that    whole    fiehis   of   the    reii 
clover   oiFer   in    vairi    .ui    ahundant   sui>ply  of  precious 
nectar    to    the    Idve-hee.       Thus   it    rni^riit   l>e   a   ;rreat 
advantaire  to  th.    hi\e-hee  to  liave  a  s'.i-htly  lonfr,>r  or 
ditterently  constructed  pridioscis.      On  the  other  hand, 
I  have  Jouiid  hy  experiment  that  the  fertditv  of  clover 
depends,    on    l.ces    visitiiit,'    and    nioving-    parU*    of    the 
condia,  so  .us   to   push   tlie  pollen  on  to  the  8ti:rniatic 
surtace.      HtMue,  aiiain,  if  humhie-hees  were  to  hecme 
rare  in  any  country,  it  mitrht  he  a  {rroat  advant.Xi:.'  to 
the  red  <  lover  to  !ia\e  a  t-hortcr  or  more  deeply  divided 
tul>e   to   its  corolla,  so  that  the  hive-t»ee  could  Ms;t  it.s 
flowers.      Tlni>.   1   can   understand   how   a  flower  and   a 
bee  iniirht  slo^sly  liecome,  either  .simtilt.aneously  or  ..n, 
after    the   other,    modified    and    adanted    in    the    nio>t 
perfect  manner   to  eacli   other,  by  tiie  contituied   pr.- 
Hervation  of  individuals  presentintj  mutual  and  slitrhtly 
tavourable  deviations  of  htructure. 

I  am  \\ell  aware  that  this  doctrine  of  nati  rai  .^elecv 
tion,  e.\ernplificd  in  the  Ml)o\e  imaginary  in-tances,  is 
open  to  the  same  objectioiis  winch  were  at  first  ur^ei! 
a-ainBt  Sir  (  harie.s  Lyeli's  noble  views  on  'the  modem 
chant'-ot.  of  tlie  earth,  as  illustrative  of  (reolotrv '  ;  but 
•  e  now  seldom  hear  the  action,  for  instance,'  of  the 
eoast-»a\es,  calle;i   a  triflinjf   and    infitiTiifira.  I   caus.*, 


NATl  KAI.   SHI.K(  TION 


87 


when  ai'|.!i('ii  to  tln'  oxcav.ition  nf  triciintif  v.illpys  or 
u»  tlu'  tormatioii  of  (lif  li«ri>'osf  luics  nt  iiiliiinl  cliffs. 
jN?»ti!nil  ■JcitM-tinii  can  act  o.ily  \>\  tin"  pri'M-rvatiun  and 
BC'-iiniiilatioM  of  i!itiiiitf'?.iinally  -iin.-ill  inluTite<l  nunl' 
ticatioiis,  pach  j.rofifaMe  to  the  j'rt'-iorv«'<l  \,o'\nn  ;  anil 
a>4  mo'icrii  ir*->>lf>ixy  h.-w  aliii'j>t  ii  iiii->ht>il  nuch  vihms  as 
the  oTcavatiofi  of  a  yreat  \all<'y  liy  a  ^i(lul^•  diluviai 
wave,  -()  will  i.at'iral  Ki'hvtion,  if  it  i>o  a  triie  princinle, 
Lariinh  thr  tiolit-f  of  the  cotitinin  a  creation  of  iu".v 
(<r;i^ariio  tx'iiii:^,  or  of  any  ^rcat  and  «u<lclen  inotlification 
Hi  their  structure. 

On  the  hitfrcnjitijig  nf  IndinditnU. — I  must  here 
introduce  a  s)iort  •liure>si(iii.  In  the  cose  of  animals 
md  plants  with  ^.eparateil  ^^'xes,  it  is  of  course  obviou3 
that  two  individualw  must  al«ay:»(with  the  exception 
of  thti  curious  and  not  welI-uii(ier>tood  rases  of  par- 
thenoirenesis)  unite  for  each  hirth  ;  hut  in  the  ca.'w  of 
hermaphrodites  tliis  is  f.ir  froni  olivious.  Nevertheless 
I  am  strongly  inclined  to  helieve  that  with  all  hernia- 
plirodites  two  indivitliialn,  either  occasiiinalic  or  haliitu- 
ailv ,  concur  tor  the  reproduction  of  their  kind.  I'hiH 
view  WH.X  first  .^ujjire.-ted  by  Andrew  Kni^'-ht.  We 
liliall  presently  see  its  im{>orL'ince  ;  hut  1  must  hero 
treat  the  guhject  with  extreme  hrevity,  thoutjli  I  hav.' 
the  materials  )>repar(>d  for  an  amjtle  di>cu.«»i(in.  AH 
vertebrate  aniniai.-.,  all  .nsect^s,  and  some  otiier  lar^e 
grt)upH  of  animals,  j)air  for  ea<:h  birth.  Modern  re- 
search has  much  diniini>!uMi  the  nmnber  of  .supposed 
hermaphrodite>,  and  of  real  }iermaphr(»dites  a  lart,'e 
numl)cr  pair  ;  that  i.s,  two  individuals  rcirularly  unite 
for  reproduction,  wliich  is  all  that  concerns  us.  Hut 
still  there  are  inaiiy  hermajdirodile  animals  which 
certainly  do  not  haiiitually  pair,  and  a  vast  niajuritv 
of  plants  are  hennaphrodites.  What  re.uson.  it  may 
He  a«ked,  is  there  for  supposinc  in  these  rases  that 
twu  individuals  ever  concur  m  rejirod notion .'  A^  it  ie 
iinpossiiiie  here  to  enter  on  deuiis,  1  must  trust  to 
«)me  general  considerations  alone. 

In  the  first  place,  !  have  collected  so  lar^'e  a  body  of 


\^:^£^;^;;^;^^^ 


88 


ON   THE   ORKJIN   OF   Sl'EClES 


mtL^ 


it 


farU,  Hhowinc,  in  acoonlaiire  with  the  almoMt  univpp«| 
}>elit'f  onircfiiors,  tliat  wi»h  animals  and  plants  a  croM 
}»ot\vet'ii  difioriMit  varictifs,  <»r  l«'t\vfcn  individiialH  of 
tlu^  ^-imo  variety  Imt  of  another  str.iin.  irives  vitrMur 
and  fertility  to  tlie  otf-prinif  ;  and  on  th(?  other  )iand. 
that  r/oM'  interhreedin^-  iliiiiini>hos  Mj-oiirand  fertilitv; 
th.it  thf-i-  tai't- alone  incline  me  to  !ie!ir\e  that  it  i<i  a 
^--eneral  law  of  nature  (ntterlv  ii,'-norant  ♦iiouirh  we  he 
of  the  ine.ininL'  "f  tlie  la\i ')  that  no  or^Mnic  heintr  >«<-if- 
fertili-fs  it>flt  fnr  an  eternity  of  trenerations  ;  hut  that 
arro-i--  with  anotiier  individual  is  occasion. iilv  -perhaps 
at  very  lotur  interNal-      indi.-j..ns.ih!i\ 

<  )n  the  hclief  that  this  is  a  law  r)f  nat'ire,  wi>  lan,  I 
think.  ii;i(ier>tand  several  larire  ola--e-i  of  fu'ts,  >uch 
as  the  lollioviiiir,  whhh  on  anv  other  \ieu  nre  inex- 
plieahle.  Kvery  hvhridi/er  knows  duvv  u-iravioirahle 
expM^ure  ro  wet  is  Ut  the  fertilisation  of  a  li.rwer,  vet 
what  ,1  inul'itnde  of  (hiwers  )iave  their  anthers  and 
sti'.'inas  filly  e\j)o-i'd  to  the  \\eather  !  Init  if  an  oira- 
sional  .r.i-ii  ho  iixii-pensat.le.  the  inllest  freedom  r..r 
the  entranr.'  of  pnli.Ti  from  another  individual  \v;ll 
explain  this  -tatt!  ot  e\'pn>nre.  more  esperiallv  as  the 
plant's  own  antliers  and  |)i-t;l  i:<'tierall>-  stand  so  eh.^e 
toirether  tiiat  >«di-fertili>ati«>n  s.^ciiis  ahno>t  iiuniUilde. 
Many  ilowers,  on  the  other  hand,  have  tiieir  ortrans  of 
friictihcation  ,h.-ely  enclosed,  as  in  the  ;rreat  tiaj.i'.io- 
naceoiii  or  pea-t'amily  ;  hut  in  sfwral.  perhaps  m  ail, 
such  flower-.,  there  is  a  verv  curious  :id;i{it;ition  fietween 
the  structure  of  tlie  liower  and  the  manner  in  uhich 
hees  suck  the  nectar;  for,  in  dointr  this,  they  ether 
pu-h  the  )'(u\er's  own  pollen  on  the  sti.rma,  or  hnntf 
poilen  troui  annthcr  limver.  So  nece»ary  are  tlie 
visits  of  hc>'s  •(!  papilionaceous  flowers,  tliat  I  have 
fiund,  hy  expennionts  puhlished  elsewhere,  that  their 
U'riility  is  trreatly  dnninished  if  tliese  vi.-its  ho  pre- 
vented. Now.  it  1^  scarcely  possible  that  Ix-es  should 
fly  from   flower   to   ihaver,  and   not  carrv  [I'dlen   from 

•  '.    •"   ■■■■■i-  i;:v^--  iiT-;:,  .t.-    •      •fiif-.c,   o;    rf;o 

plant.      Ihes  ^ill  ;ict  like  a  camel-hair  pencil,  and  it  i-i 
quite  sulK.icnt  just  to  touch  Itie  anthers  of  one  f'jwer 


I 


■^V:>-.  '•;•:^J^^^i';y^,:tJJ|^ 


NATURAL   SELECTION 


89 


and  then  the  ctiirma  of  another  with  the  ««nie  brush 
U>  ermiire  tertilisatum  ;  but  it  mn-^t  not  he  sui«|M»»e<l 
that  l>e<'s  wouM  thus  prtxluce  a  multitude  of  h)i)rid« 
JM'twtM'ii  distinct  sjKHies  ;  for  if  ytui  briujf  on  tlie  same 
brush  a  jilaiit's  owti  jwilh'ii  and  pollen  from  another 
sjiecies,  the  former  will  lia.e  such  a  prfpotent  erfect, 
til  it  it  will  invan.ihly  and  i,om].let«'ly  iJ-'-trnv,  as  ha« 
hveu  shown  by  (i.trUier,  any  in!iuen< c  froiu  the  foreign 
Iiullen. 

^\  h»'u  the  .-it.inien.s  of  a  liowor  xuddenlv  !<prin<f 
towards  the  pistil,  or  nlowly  move  one  after  the  other 
towards  it.  tlip  mntrivante  seems  adipted  sololv  to 
ensure  self-fertilis-ition  ;  and  no  dout»t  it  is  usefif  for 
this  end  ;  but,  the  a^'ency  of  inserts  is  often  re<juired 
to  I  aiiv  the  stamens  to  .-priii:;  rorwar-i,  as  K  'IreiUer 
has  shown  N»  \iv  ilo;  case  with  the  barberry  ;  and  ia 
tlii<.  very  trt'iius,  wln.li  st-ems  to  have  a  sp«'cial  -  ontri- 
vaiice  for  srlf-fert:li-.-ition,  it  is  well  known  that  if 
clo-ely-allied  forms  or  varu-ties  are  plante<i  near  each 
other,  it  is  hardly  posMhle  to  raise  |>ure  see<iliiiirs,  go 
lar;;ely  do  they  natiirally  <-ross.  In  manv  other  cnsos, 
far  from  there  l)einjr  any  aids  for  M*lf- fertilisation, 
there  are  special  contrivances,  as  I  couid  show  from 
the  wntin^fs  of  (.  C.  Spre!ii,'el  and  from  mv  own 
oliservatiuns,  which  etfectually  prevent  the  st'ifma 
reoeivine  pollen  from  its  own  flower:  for  insUmce, 
in  l^iU'lia  fulireus,  there  is  a  re-ally  beautiful  and 
elaborate  contrivance  by  which  every  one  of  the  infin- 
itely numerous  poUen-ifranules  are  swept  out  of  the 
conjoined  antliers  of  eacli  riower,  befdre  the  stiirma  of 
that  iiulividual  liower  is  ready  to  receive  them  ;  and  as 
this  ilower  is  never  visited,  at  least  in  my  ^nrdt^u,  by 
insect,s,  it  never  sets  a  seed,  thoutrh  by  [ifacini;  [.uUeu 
from  one  fbiwer  li-i  the  stitrma  of  another,  1  rai:jed 
plenty  (tf  seedliiiL^s  ;  and  ^llilst  another  sjiecies  of 
I/olieiia  trrowintr  close  by,  which  is  visiied  by  bees, 
see<ls  frwly.  In  \ery  many  other  ca>.».s,  tbouifh  there 
be  no  special  mechanical  contrivance  to  prevent  the 
stit'tiia  of  a  flower  receivin::  ts  own  [xillen.  y(>l,  aa 
C.  C.  Sprencfel  has  shown,  nun  as  i  can  confirm,  cither 


r:«»'P 


•Vii 


sai 


9<> 


(»N    THK    (•UKJIV   OF   SPECIES 


iht  .iii'-tii'i'-'  hur^l  licrmi'  tn.-  .,•  -i  i  i  ii  ri'inly  for  tfitil- 
i»«.it;i»ii,  <ir  tin-  •-iuiri.'i  i-^  lo.'idy  ttj-fnri'  tli»*  [i()!l»>n  of 
that  )!iiwer  i-  rtudy,  no  th.it  llii'-c  jilatiU  liave  in  f.irt 
M'j»ar:it«'il  f«exeM,  amJ  rnu>t  li.-\liitual!y  Ik*  <  ro«i«.«'d.  How 
Ktr;i!._M'  are  tlifse  facts  !  Iliw  stran;:e  that  tlie  |>ollt«ri 
and  .^tii^riiatic  "irfacH  of  t!iu  -uiio  Jiowi»r,  ttiouirh  phict'd 
Ko  rlosi"  toifplli.'r,  .l^  if  (or  ihe  vitn  juirito-r  of  self- 
fcrtilifNation,  «.houl(J  in  so  many  fa-i'-  lie  mutually 
•i-oli---;  to  ci'  1;  otlif-r  '.  H"«  -imply  arc  ihe-p  farts 
eiplaiM'd  on  til"  vic'.^  of  an  <i<Ta>i'ii,,il  rro-n  witli  a 
diHlincl  i:idividiial  la'injf  ad\ant;ii(fOii!*  or  nuiisjjon- 
«ai<l«'  ! 

If  sfvt-ral  v.iru.'tif'*  of  llit.'  laliliairu,  radi-<h,  onion,  ami 
of  Mtrno  otlitT  plant".,  1>«  alinwod  to  K»»cd  near  each 
otlioi,  a  l.irtre  niri Ontv,  a"  I  have  found,  of  llit'  seedlinjo* 
ihuh  rai->;d  will  turn  out  iiiontrrel.i  ;  for  instance,  1 
raisod  2."i.'{  s«»odlinu  cahha;rt's  from  some  plants  of 
ditferent  variolie-.  f^rowiiiij  near  eai-h  other,  and  <>i 
those  only  75'  were  truB  to  their  kind,  and  some  even 
of  tl'e.ie  were  not  |)erfc<f  !y  true.  Vet  the  pistil  of  each 
cah  .ifo-flower  is  Burmunded  not  only  by  ita  own  "ix 
stamens,  hut  by  those  of  the  many  other  flowem  on  the 
same  plant.  How,  tiien,  comes  it  that  Huch  a  vast 
numher  of  the  seedlin;rs  are  mongreli/ed  ?  I  gus{»ect 
that  it  must  arise  from  tlio  pollen  of  a  distinct  tv/n>^y 
haviiiij  a  prepotent  etfect  over  a  flower  s  own  pollen  ; 
md  llial  ti^s  is  pari  of  the  general  law  of  >rood  heine 
derived  from  the  intercrossinif  of  di'^tinct  individuals 
of  the  same  species.  W  hen  distinct  *7>»<tc*  are  crossed 
the  c^-ks*  is  dirtv  tly  the  reverse,  tor  a  filant's  own  pollen 
18  alway*  pre[>otent  over  foreiirn  j)ollen  ;  but  to  tlti* 
subject  we  sh.ill  r«>turn  in  a  luturo  chapter. 

In  the  aise  of  a  trijrantic  tree  covered  with  innumer- 
able tlowers,  it  rna\  be  objected  that  pollen  could 
seldom  tH*  (Uirried  iVom  tree  to  tree,  and  at  most  only 
from  flower  to  flower  un  the  s-ime  tree,  and  that 
flowers  ou  the  same  tree  can  be  considere<l  as  distinct 

iJlUo  itiu<ti^     i*uiv     in     it     iitnit<-«i     Sriinc.        i     i'viie^c     liiis 

objection  to  be  valid,  hut  that  nature  h.vs  largely  pro 
Tided   atra:n^t  it  by  giving  to  trees  a  stron?  tendency 


^^^-.?m^t^€^ ^  ^r^'^^'*^y--'w:  ^f^im*^'^ 


«* '  *  f-Lj^it^.,  Jut  J 


Mm 


VATf  KAL   SEI,K(TI(>N 


0] 


M.  >.f.ar  flower-  -iiri  He|iarat<'d  m-xch.  Wli.'ii  th**  vexr^ 
irt-  M'par,iU-.i.  .wlhoi.^;!,  tli,-  tn;il»'  nun  tviuilv  f!(,vvi>rh 
nav  l.e  prtMiiir*'/!  ..ii  th»»  -ame  tn-e,  we  rin  ««.»>  th.it 
..i;liMi  inii»t  l>i'  rtv'.J.irly  farru-<i  from  tir.M,.r  t..  Hmver 
umI  thw  will  j^ivp  H  M'.r  .  fiaiirr  of  j,„ll.'u  U-mi,^ 
•'<.;i.-.i(,iially  rarrie.l  fr..in  tr<'«'  tn  tri«r  Tliat  trr«i« 
irt'I.'i!jfii,£T  tn  all  Or.lerh  liav.-  thoir  Kt-xcv  more  oHni 
««eparal-.!  tha:.  rtthor  f.laii!..,,  1  fin.l  t..  \»-  the  ra-t.  in 
ihi!-  country  ;  an.l  at  my  rp(|iie8t  I  >r  H.Mjkor  Ubijlat»-d 
ifii.  trtH;.s  „t  N,.v*  /(.aland,  and  Dr.  Asa  (iiav  lliosfl  .,/ 
Ih.  I  niti'd  SUit.'s,  and  tlip  r^Kult  v*;u  ;is  1  anticipated 
On  the  other  hand,  l>r  Hooker  ha>,  recentiv  informed 
'lie  that  he  finds  tliat  the  rule  dr>eH  not  hold  in 
Australia;  and  I  have  made  these  t«w  remarkn  on  the 
Hexes  of  trecH  sitnnly  to  call  attention  to  the  suhjeot. 

lurninir  for  ;»   very  hrie'  space  to  aiuniaN  :    on  the 
land  there  are  some  hermaphro<iites,  as   land-moUusca 
aud  eartli-worms  :    hut  these  all  })air.      As  yet   J   have 
iiot  found  a  sin^rlo  case  of  a  terrestrial  animal  which 
fertilises  itself.      We  can   understand   ihis  remarkable 
;act,  which  offers  «o  stroiiir  a  contra>t  with   terrestrial 
plants,    un    the    view    of   an    occasional     crong    being 
iiidisiMMisatde,    bv  considerinjf  the    me.liiun    in   which 
errestrial  animals  live,  and  the  nature  of  the  fertilising 
element  :    lor  we  know  of  no  me-ans,  analok'ous  to  tiie 
action  of  insects  and  of  the  wind  in  the  case  of  plants, 
'•>    which  an   occasional    cross   .ould    he   t-lFected   with 
terrestrial    animals    without   the    concurrence    of   two 
individuals.       Of    aquatic    animali*,    tliere    are    many 
self-feniiising   hermaphrodites;    but  here   currents   in 
tJie   water  offer  an  obvious  means  for   an    occasional 
cross.      And,  .as  in  the  case  of  flowers,   1  ha\e  as  yet 
tailed,    after    consultation    with     onf    of    the    }.-ir},'t.>t 
•luthorities,   nanjf-iy,    Professor   l!ui!,-y,   to   dLscover  "a 
smt'le  ca.ve  or  ;in  tu<rtn.t[''n..drite  animal  with  the  or^ns 
of  reproduction  so  perfectly  enclosed  within   the  Unh, 
that  access  from  without  and  the  otca-sional  infiuenci^ 
ui  a  distinct  iiidivuiual  can   be  «hown  to   be  physi.-aHy 
imjK)ssible.     (  irripede.-  lontr  apjx'areu  t..  me  to  present 
a  r  .SH  or  very  »rreat  difficulty  uiiJer  thi*  point  of  view 


02 


ON    IHK  ()UM;IN   i»F   JSI'KC  IK^ 


hut  \  liav(«  )non  «ina)ilod,  by  a  fortunate  charic*, 
el-owl^Tt*  to  jirovp  tliat  two  iiuliviiliiaU,  thoiiu'fi  f>otL 
»r»»  H«'lf-N>rtil>".iritr  iiprni.ipliriMlit*'-,  <to  •<iiiif>f iriuM  rr(»H«. 

It  rmist  liriw  •^tnirk  nt<)>*t  iiatur.tli-^f s  m*  R  ntraiitre 
anoni.il\  fli.it.  m  'Im*  cas*"  of  Imth  .inini.iU  aiul  pl:itit«, 
<<i»ori«'«*  of  till'  Kanio  fitnily  ir.d  I'vi-ri  ot  ttio  -.iine  irfinis, 
tfioiiifli  atrreeinj:  ••lo-'ely  witli  racli  otImt  in  alinoht  their 
■.vhi)l««  or  riJiivit  on,  vet  arn  not  ran>lv,  lomt"  of  th«>m 
ii«rrMa|)lir«>i|it«'s,  anil  "tornc  at  llcin  iini-i'\'ial.  lint  if, 
i!i  fai't,  all  i!«Tni-ij'hro(iit'»s  -lo  ocra-ional'v  iTiten-ros^ 
with  other  imiivuliiaN,  the  ditfori'iiro  h»'f*i<'n  luTiiia- 
jitirtnliti's  an'i  tuiKcvii.il  ^pt'cipx,  a>.  far  at*  fuiiftioii  i-« 
con«'oru»*(i,  l;««i-onu's  vorv  hiii  ill. 

From  thi'si'  KtMt'ral  c'on.'«i(ierat!otH  arul  troin  iho 
manv  i«i»»'r.al  fru-ts  whith  I  have  coil»».  te<l,  hut  winch  I 
ain  not  hrrt*  ahh-  to  iriw«,  I  am  «troriu'ly  incl'it'tl  to 
^u^p<*«•t  tiiat,  hoth  111  the  vot:»'tahle  and  aainial  Ki'i^f- 
'Ji,in».  an  o(  rational  intercross  with  a  diHtitirl  individual 
ii  a  law  of  nature.  I  am  »oll  aware  that  there  are,  on 
ilii.-i  view,  many  cases  rjf  tiifficulty,  some  of  which  1  arn 
trying;  to  invest :::ate.  Finally  then,  we  may  conclude 
lliat  in  manv  oriranic  heint^,  a  crosn  Iwtween  two 
mdivid'ials  is  an  ohvioun  ncessity  tor  each  hirth  ;  in 
rnany  others  it  occurs  perhaps  only  at  lontr  intervals  ; 
but  in  none,  as  I  8us{)ect,  can  Helf-fertilisatioii  »fO  ou 
for  porpe^iity. 

(Sriirii>t'nivft  ftn-o^irnhU  to  Satiirnl  f^flfctxon. —  I'hiH 
\»  an  extremely  intricate  Huhject.  A  lartre  amount  of 
LnheritJihle  and  diversified  variability  is  favourable,  but 
I  believe  mere  individual  dilierences  sutRie  for  the 
work.  A  liri'o  number  of  individuals,  by  g-ivinjf  a 
b«tter  rhainc  for  the  appearance  wthin  any  tiven 
period  of  prolitaMe  variations,  w:ll  compensate  tor  a 
!e>M»r  amount  of  variaiiility  in  each  individual,  and  i*, 
I  bflieve,  .in  e.xtrtmelv  important  element  of  success 
'Hiouj^rh    'laturo   yrantrf    viist   period.s   <tf   time    tor    tiie 

infiotiiiite  jicrioci  ;  for  :\.m  all  urfcraiiic  l>eine«  are  ntrivinif, 
it  may  be  *aid,  to  Kiuze  on  each  jiUure  in  the  t^  m^my 


NATI  KAL   .SKI.ECTION 


yn 


lit  nature,  if  »nv  'Uie  Nj>«»rio«  d<w*.i  not   UM-omo  m*Mlitic<l 
HM'I  ini[)r«)ve<i  iii  a  corrt'««p<it»«innf  il»>irri'c  with   i\n  coin 
|M'ii?<'r«i,  it  v*ill  tMiuri  l>r  pxterimnatrd. 

In  niaii'M  niotho<liral  wlettioti,  a  lirtM»<ler  •««'l«>»t«*  for 
»;»rin'  ii('tin'«>  «ilii«yt,  nii'l  fro«»  iiiterrroHsm^  will  n*1i<>11\ 
Mtiiji  hJN  wnrk.  Hut  wlii'ii  rii.itiv  riu'ii,  witl.oui  nitrni) 
mn  to  alter  lh«"  WrtMMl,  have  a  iiwirly  rommnn  ntainl-ir«i 
of  perfcrtinii .  ami  all  try  to  i;«'t  ami  l>r(MM|  (rum  l\\v 
lii'Mt  aiiiiiitU,  iiuicli  iniprovtMiiefit  ami  trnxitu-atioti 
mirt'ly  liul  nlowly  follow  from  Huh  uiiconsoioim  j)roc«>s- 
of  nelertion,  notw■ilil^taIlliiIlir  -x  l.irist*  nmrniiif  i.t 
iTossiu;;  With  interior  aiiimaU.  Mm-  ?  will  he  m 
nature;  for  within  a  ronfine'l  nrra.  with  norne  pl.tre  i. 
it<  polity  n'»t  "o  jierteitly  occupieii  a-*  niicht  he,  n.itiira: 
selerfion  will  alwavx  teml  to  [in'«erveali  tiie  imii.  iilu;il- 
\riryirij(  in  the  riL'ht  (iirectinri,  ihoiiL'h  in  different 
'h'irrees.  8o  a^*  U-tter  to  fill  up  the  uiuxTupieii  piare. 
I';it  if  the  area  he  Liree,  ii»  several  di'-trift.*'  will  almost 
(•;  rtninly  present  ditierent  coiiditionH  of  lite  ;  umi  thiMi 
if  natural  •«eleoiioii  Ik»  inutinyinjf  and  imprnvinjr  ^ 
!.jMMie«  in  the  neveral  di-trirfs,  tliere  will  he  inter 
.rofi-ing  with  tlie  o'her  individuals  ot  the  same  speeie- 
on  the  tontines  of  earh.  And  in  Um-  case  the  erie«l«. 
of  intercrossinjT  tan  hardly  he  eounterhalaui-ed  hy 
natural  r;ele<tioii  alwayrt  tendini:  to  mo<li:i,  «!!  ihe 
indivifiiial-  in  each  district  in  exactly  the  s;iriie  manner 
to  the  conditions  of  each  ;  for  m  a  oontinuou-.  area.  i!ii- 
physical  (■(Miditions  at  lea-t  will  jfenerallv  I'radn.iU- 
ii*ay  insen&ihly  from  one  iii>tri(t  to  :i:u)ther  Ihe 
mtererossmtr  will  most  affe<"t  those  animal-  wlneh  unite 
for  eiich  hirth,  whieh  wander  much,  and  which  do  not 
Ureed  at  a  very  quirk  rate.  Hence  in  atiirnals  of  lhi> 
nature,  for  instance  in  birds,  varieties  a  ill  jreneraliv 
l>e  confined  to  separated  countries;  and  tlds  I  t.elieve 
•o  \ni  the  oa.-*©.  In  hermaphrodite  or^:ani«n"s  wiiirli 
crosM  only  t)cca>ionall"-,  and  likewise  .u  aniujals  wnicii 
unite  for  each  hirth,  hut  which  wander  little  and  which 
riiii  MirrPA»©  ^i  <*  vt*rv  rspiu  icti^},  s  new  aiiu  »nipr»'iV6u 
vurit'ty  miifht  Ik»  (juickly  formed  on  any  ouo  ^paX,  and 
rnujht  there  maintain  it>ielf  in  a  body.  m>  ihal  ^hniever 


94 


ON    THE    ORItilN    OF    SPEC  fKS 


int«»rcrn«8incr  took  pl;ici'  wo-ilr;  ]>o  chiefly  brt.M<«en  the 
iiidividu:ils  <»f"  tho  same  ww  ■.ariptv.  A  local  variety 
wlien  once  ''iiis  formed  miirlit  ■siiKfiOijiierifly  ^lowlv 
Hj>r«'.i(l  to  other  flistrirU  On  the  al.ove  principle, 
Tiurscrynioi;  always  prefer  trottiiiif  seo^i  from  a  l.irtf.- 
boiiy  of  ;)iaiits  of  the  <amo  variet-y.  i'j>  the  <-harir-P  of 
intercrossing-  with  other  variftie-^  '-^  tliu-i  lessene<]. 

Kv.Mi  in  the  .-.-iso  of  -Inw-hreciint:  animalu,  which 
unite  fi>r  oruli  '.irtli,  w^  mij-;t  not  overrate  the  effects 
of  intprrrosses  in  retar<linj^  natural  i,;'loction  ;  fur  I 
can  \.nuu  a  rf»n^idprat-!e  rat^lotr,,,,  ^f  facts,  (sfmwuii: 
that  withui  tlie  -ame  area,  varieties  of  the  'samo  animal 
can_  lon;r  rtmaui  .iistinct,  from  haiintin;^  different 
stations,  from  hreedintr  at  sliirhtly  diifrrcnt  seasons,  or 
from  variotiea  of  the  same  k;ud  prcforrinif  to  />air 
totrether. 

Intercrossiriff  plavs  a  very  important  [)art  in  nature 
in  keepintr  the  individuals  of  the  sajne  species,  or  of 
the  same  variety,  true  and  uniform  in  character.  it 
will  ohviously  thus  act  far  more  ofTicimtly  ^ith  those 
»n;  mal<  which  unite  for  (vich  birth  ;  t.ut  I  'haM>  already 
attempted  to  show  that  we  have  reason  to  hdieve  that 
oc<asional  intercrosses  take  place  with  all  animab  and 
witli  all  plarjta.  Kren  if  these  take  place  unlv  at  Ion? 
mtcr\a!s,  I  am  convinced  that  the  yountr  thus  pro- 
duced will  piin  so  much  in  M:,'our  and  fortility  ovor 
the  offsprintr  from  lonjr-connnued  self-fertilivition, 
that  they  will  have  a  l>etter  chaiice  of  surviving  and 
prop;u.>:it;i::  the'r  kind  ;  and  thus,  in  the  lonsr  run,  'he 
influence  of  intercrosses,  even  at  rare  intervais,  will 
be  trreat.  If  tluTo  exist  orirani'-  beirij^d  which  never 
intercross,  uriitormity  of  character  can  ho  retained 
biuontrst  them,  as  lonir  as  their  conditioTie  of  life 
remain  the  Mime,  only  tlirouirh  liie  principlo  of  inherit- 
RTice,  and  throutrh  natural  selection  dc^  royin^  atiy 
which  depart  from  tho  proper  typo;  !  ut'  if  their 
conditions  of  life  cl  anue  and  thev  uiidertro  inoditic^tion 

—  :*■ :i..      r   .1  .  I        ^.  .      .  .. 

!.:;:.:.  ..;..^    ,;,    .;;.;.  .iClJ'"  Caii    uCui'ieii     to    iil»']r    IllOO'ineo' 

offspriMff,   solely    by   natural   selection    preserving    the 
•aia>'  fav,.iurabie  variations. 


NATLl'AL   SKI.KCnoN 


9. -5 


Isolation,  al«<),  isan  imjiortant  olemont  in  the  {»riM  es»i 
nt  natural  seloctioii.  In  a  ronfita-d  or  isolate<l  area,  if 
not  vory  larce.  the  organic  atnl  inorjiranic  con<!itio!i7(  ot 
life  will  /rt'iierally  l>e  in  a  yreat  ileifrt-f  uintorni  ;  so 
that  natural  •jpU'ctinn  will  tend  to  nnxlifv  all  tli** 
indivitluais  of  a  varyint:  ^pffies  throuthtmt  Mie  ir»*a  m 
th»»  HaiiH!  manner  '.n  rpla'ion  to  the  siiine  coiiiiiiions. 
Interrrn-,st>«,  also,  with  tht-  individuals  of  the  name 
sj  cries,  which  othenv;<,'  would  have  iiihahited  thi- 
surroundintr  and  dirfiTiMitly  rircutn-tanced  (ii?,tricti<, 
will  hf>  prevented.  liut  i.'i<datioii  prohahly  acts  tnnre 
effirientiy  in  clieckintr  tlie  immigration  of  hetter 
adapted  ctriranisms.  atter  any  nliysical  chantre,  suth  a>« 
of  climate  or  elevation  ot  the  land,  etc.  ;  and  tlius  new 
pla^-  in  the  natural  economy  of  the  country  are  lett 
open  for  the  rUl  inhahitantM  to  8tnif«-le  for,  atid 
become  a<lapted  to,  through  modiiicatiotH  in  their 
structure  and  constitution.  Lastly,  isolation,  hv 
cht  Ainjf  immi^^ration  and  -onsefiuently  ci>m{»etition, 
will  (five  time  tor  any  new  variety  to  1)0  «lowly  im- 
proved ;  and  this  may  sometimes  \ni  of  imi»orLanoe  in 
the  production  of  new  .si>ecie.s.  If,  however,  an 
iKoIated  area  he  very  Hmali.  either  from  loinjf  «ur 
rounded  l)y  farriers,  or  from  having-  very  peculiar 
physical  conditions,  the  total  i.umher  of  the  individual 
supported  on  it  will  noces.sarily  he  very  smaU  ;  and 
fewness  of  individuals  will  i;reatly  retard  tiie  (tro<luc- 
tion  of  new  spei-ie^  throutrh  natural  selection,  by 
decreasing  the  chance  of  tiie  appearan<-e  of  favoi;rr»'de 
variations. 

If  we  turn  to  nature  to  test  the  truth  of  these  re- 
marks, and  look  at  any  •^m:\\]  isolated  area,  such  ,i.s  lu 
oceanic  islanrl.althouL'h  thetotai  number  of  the  specie? 
iiihaliiting  it,  vill  be  tound  to  be  small,  a**  we  sliall  ^ee 
in  our  chapter  on  treographual  dntribution  ;  yet  of 
these  specuvs  a  very  large  proportion  are  endemic,— 
ttiat  is,  have  beei:  prod!i(.e<l  tiiere,  ind  nowiiere  elt>f 
lieiice  an  0C'6aiiic  isiaml  al  iiril  Muhl  -'••eii;»  u»  uavf 
been  highly  favourable  for  the  |)ro<luctic»n  of  new 
!-pecie«.     But  we  may  thus  greatly  de<eive  oursfllve^ 


I', Ml 


96 


()\    TUK   ORIGIN    OK   Sl'ECIES 


for  to  ascertain  wlicthcr  a  sni.ill  isdl.itcd  ari'a.  or  a 
liT'jo  n|i(Mi  arra  iil-..'  a  coiitiiiiMil.  li.i-  lii'cii  most  f.'ivour- 
aiii«'  for  tho  jiroi'iifiKiii  ot  immv  orj/anii'  torins,  u«'  ouLrlit 
to  inako  tlif  r()nniari>.<pii  \\  iiliin  tMju.il  lime-^  ,  and  thin 
w«'  arc  in.  .iii.ti-lt'  ot  (ioui^. 

V!t  li'i'i:ii!  I  111)  ii'it  (iowht  tliat  isni'itidri  in  ot  ronnider- 
»lile  iin|)ortanc**  in  tnt-  proiiiKtin:;  o!  new  Kjifi-ifs,  on 
tin'  \vli(»li'  I  run  iicliiifd  to  l«eiunp  that  htr;:t'tif's>  f»f 
arra  i«  oi  trMirt-  iiii[Mirtanc»',  riioro  especial  1\'  in  the 
prodiK'linn  ot  ^!.l•^i('s,  M);i(ti  will  ]ir.i\t'  rapahie  of 
eiKiurinir  tor  a  h'lij  jicriod,  and  of  ••|iri>a»int:.'  \vi<i«'iy. 
Tliroui/lioiit  a  ;:rtMt  aii«l  o]n>n  at«'a,  not  oniv  w.W  thrre 
be  a  In  Itc:  rhauif  ot  lavoiuahlo  \'ariaiions  a ri >•  i ; i ir  from 
til'"  larL'f  jiiiTiihcr  of  iinii\  iiiuais  of  the  ^aiiic  -iit'cios 
tlicii-  -iipjmr  c'l.  'vit  tlic  rondit jous  of  litf  are  ini'iiitely 
corii|'if.\  troin  tlp'  iarj.'*'  nuinher  of  alre.idv  exi^tinp 
BpecJc^  ;  and  it  some  of  these  many  spn  le-  liei  onie 
modi*iod  uid  iniprove<l,  others  will  have  to  tie  improved 
in  a  corrt'spondinir  deirree  or  tliey  will  he  e.vterminaied. 
Kacli  iif>v  inrni.  aho.  as  soon  a-*  it  ha.-  heen  mucli  im- 
pr«>vt'(i.  will  he  aMe  to  -;ireaii  o\i'r  the  open  and  ron- 
tiniHMi-  .".rt-a.  ami  \<ill  thiis  conic  into  romiic'ition  with 
main  others.  Ilcuce  more  new  plaec-  uill  iic  formed, 
■ijd  till*  rornt"..-,  ition  to  till  tiieni«ill  he  ni.  re  sc\ere.  on 
n  laruc  th.i'i  on  a  small  and  isolate]  area.  .\Iorco\  or, 
preat  ar»':i>.  tlioiiL'ti  no\\  continnou-i,  ow  injT  to  o-<il!a- 
tions  ot  !( cl.  vmII  ottcn  h;»\e  recent  iy  e.\istc<l  ni  a 
hrokcn  roi!  iitio'i,  so  th.it  the  sjood  eticct.s  of  isolation 
wiii  t.''encr..ii  >  .  to  a  ecrtain  extent,  h.ive  roncurred. 
Finally,  i  concl'iiie  that,  although  'nriil  i^oi/itcd  areas 
prol>a)ils  ii.i\e  h('<:i  in  some  rc-pect.-  hit'iii)  ia\ouraMe 
for  the  jirodtictioti  of  new  '-].e(ies.  yet  that  tlie  t  onrse 
of  inoiii'H  ation  will  trenerailv  ha\e  heen  more  rapid  on 
lartTc  areas;  and  \»hat  is  more  iniportant,  th.it  the 
new  funiis  {)rodiieed  on  lar;/p  aieas.  which  already  have 
heen  virtonoiis  over  inanv  competitn.'-'i,  will  1»^  thot* 
that  will  spre^id  most  widely,  will  g-ive  rise  to  mo«t  new 
>arieiic-  ,ti  i  >pcci(^,  anu  «iii  iiiii-  piav  an  Mii|Mjrt:int 
{►art  in  tlie  chan^'inc  history  of  the  organic  world. 

^V  e  ean.  perhajw,  on  these   views,    understand  gomt* 


NATURAL  SELECTION 


97 


t»rU  which  will  be  airaiu  ailuded  to  in  our  chapter  ou 
geo^aphical  distribution  ;  for  instance,  that  tin;  pro- 
ductions of  tlio  smaller  coutiueiji  of  Australia  have 
formerly  yielded,  and  apparently  are  imw  yieldintr, 
before  those  or"  tli«'  Jarfrer  Kuropjeo-Asiatic  area.  Ihtis, 
alno,  it  is  that  continental  productions  liave  everywhere 
hecdme  so  largely  naturalised  on  islands.  On  a  small 
island,  the  race  tor  life  will  liave  been  letw  severe,  and 
there  will  ha\o  been  less  modification  and  less  exter- 
mination. Hence,  perhaps,  it  comes  that  the  flora  of 
Madeira,  according,'  to  Oswald  Ueer,  re>enibles  the 
extinct  tertiary  flora  of  Europe.  All  fresh-water  basins, 
taken  to^'elher,  make  a  small  area  comiiareti  with  that 
of  the  seii  or  of  the  land  ;  and,  conse.iucntly,  the  com- 
netition  between  fresh-water  productions  will  have  been 
le«B  severe  than  elsewhere  ;  new  forms  will  have  been 
more  .slowly  formed,  and  old  forms  metre  slowly  ex- 
terminated. And  it  is  in  fresh  water  that  we  find  seven 
genera  of  (ian»»id  ti.shes,  renniants  of  a  once  pre- 
ponderant order  :  and  in  fresh  water  we  rind  some  of 
the  most  anomalous  forms  n»»w  known  in  the  world, 
as  the  Ornithorliynclujs  and  Lepidosiren,  which,  like 
fossils,  connect  to  a  certain  extent  orders  now  widely 
separated  in  the  natural  scale.  'Hiese  anomalous  forms 
may  almost  be  called  living  fossils  ;  they  have  endured 
to  the  present  day,  from  havintr  inhabited  a  conrined 
area,  and  from  having'  thus  been  expo^ed  to  less  severe 
coni  petition. 

To  sum  up  the  circumst-inces  favourable  and  uri 
favourable  to  natural  selection,  a8  far  as  the  extreme 
intricacy  >f  the  subject  permits.  I  (onclude,  lr>okintr 
to  the  future,  that  for  terrestrial  pnxluctions  a  lartje 
contineuUil  area,  which  will  probably  under^'o  manv 
oscillations  of  level,  and  which  consequently  will  exb<t 
for  lon^  periods  in  a  broken  condition,  Ls  the  most 
favounible  (or  the  production  of  many  new  forms  of 
life,  likely  to  endure  lon^  and  to  spread  widely.  For 
tJie  area  rirst  existed  as  a  continent,  and  the  nihabitants, 
at  this  period  numerous  in  individuals  and  kinds,  will 
have  been  subjected  to  very  severe  competition.     U  hen 

H 


f 


:'^^m^^^^'^ 


un 


<»N     I  HK    OHKIIN    OF    SPE(  IKS 


coiivprled  \t\  -lihsi'liMir*)  into  larir*'  separate  islands, 
tlnTf  will  still  I'.v-t  many  imiiv  iiiiial.-.  of  the  -lame 
Bj»«-cii«s  on  cicli  isi.in.l  :  intt'nros>in::  on  the  rontinos 
of  thtj  ran^o  of  each  s|H'cu's  will  tluis  he  cluM'ked  : 
atler  j»h\-i.  .1!  ciianiie-  dt  .1:1  v  kin  I,  immigration  w)ll 
lie  pniventeii.  so  tiiat  new  j. faces  in  tiic  |m)1iIv  of  each 
i-.la!nl  will  have  to  '  •  lilleil  tip  liv  moiiiliiatioiis  ot  the 
oi<l  nihai.i:ant>  ;  ana  time  will  tie  allowed  for  the 
varieties  in  each  to  hecomewoll  inodi'ieil  and  periecied. 
When,  hy  renewed  eie.ation.  the  i-i,ind»  >.li;ill  !,<.  re- 
converted into  a  continental  area,  tiiere  w:ll  a^ain  1h» 
severe  cornpetit  ;on  ;  the  most  fav<»ured  or  iinproved 
varieties  wili  he  enahied  to  tJj.read  :  tiu-re  will  i.e  much 
evtini'tion  of  the  ie>s  improved  forms,  and  the  relative 
proporiional  iiiiml>er«  of  the  various  inhahitants  of  the 
rei.>ewed  (ontineiii  will  a^raiii  he  chan;:ed  ;  ami  airain 
there  will  i.e  a  fair  heM  lor  natural  selection  to  im- 
prove still  further  the  inhahitants,  and  tlius  produce 
new  Hjtecies. 

That  natural  selection  will  always  act  with  extreme 
Blowness,  1  fully  admit.  Its  action  depeinls  on  there 
l>eintr  places  in  the  polity  of  nature,  which  can  ho 
better  occupied  hy  some  of  the  inhal)itants  of  the  country 
uiiderjfouit:  nioditication  of  some  kind.  The  existence 
of  such  places  will  often  depend  on  [diysical  chantrea, 
wliich  a  jrenerally  very  slow,  and  on  the  immieraliou 
of  lietter  adapted  forms  havintr  been  checked.  Hut  the 
action  of  natural  selection  will  prohaldv  still  oftener 
dei'Ond  on  some  of  the  inliahitants  hecomiiiij-  slowly 
modified  ;  the  mutual  relationi*  of  many  of  the  other 
inhahitants  heint:  thus  disturbed.  Nothing'  tan  he 
prTected.  unless  iavourahle  variations  occur,  and  varia 
tion  itself  is  ni)parently  always  a  very  slow  process, 
llie  process  will  often  he  L'reatlv  retarded  hv  free  inter- 
cro.ssniii.  .Many  will  exd  iim  that  these  several  causefl 
are  amply  sullicient  wlndly  to  stop  the  action  of 
natural  selection.  I  do  not  believe  so.  ( )ii  the  other 
Land.l  do  iieiie\e  thai  natural  seiectuui  aiw.ivs  acts 
very  slowly,  often  only  at  loriir  intervals  of  time,  and 
(fenemlly  ou  only  a  very  few  of  the  inhabitants  of  the 


-^ 


4 


NAM  KAL   SKI.KCllnN 


IKi 


lamo  rpfrinu  at  the  «ianio  timi*.  1  furf)it>r  h«'li(«\o.  tlml 
tliiN  very  .-i(tw  .  iutiTriutTent  ;ii-tioii  ot  natiinii  solcriioii 
acronls  pertettiy  w»'ii  witii  wliat  trfolotry  toils  u.s  of 
the  rat*!  and  niainuT  at  vvluri,  the  mlialutaiits  of  tJiin 
worifl  has*'  <  liain.'t'<l. 

SiowttuHit^h  till-  process  of  ■seiectinn  fii.,v  !«•<,  if  feohlo 
Tiiaii  can  do  niut  ii  bv  fiis  ()>m»>rfl  of  MrtiriiMi  M-leftiois, 
i  cat!  see  no  limit  to  the  aiiumiit  of  chaiii.M'.  to  the 
it'.itity  and  niiiinie  ron)[.li-xity  of  the  coadiiiitalions 
bftAcfii  all  ortfanic  heiMtTv,  one  with  anoili»T  and 
vviiti  their  |ihysic;il  oonililions  of  iife,  wh;rh  may  he 
er'eited  in  the  iont:  course  of  tim»>  tiv  nature  -  power 
ot  selection. 


h'.itinrtion. — 'i'his  Mihieet  will  he  more  fully  di-cusseii 
m  our  chapter  on  (ieoiotry;  l>ijt  it  mu.-t  he  here  alluded 
to  from  \mns  intimately  connected  with  natural  nelec- 
tion.  Natural  selection  acts  M>'ely  throuali  the  [ire- 
>iervation  of  variations  i:-  ssime  way  ad\ai.r.u:eous.  w  liich 
consequently  endure.  Hut  .la  from  tlie  hiyii  geometrical 
ratio  of  increai-ie  of  all  ortranic  l»ein{fs,  each  area  it 
already  fully  stocked  with  inhahitanLs,  it  follows  that 
an  t^ach  heleote«i  and  favoured  form  increa-ses  in  numher, 
so  will  the  le»iH  favoured  forms  decrease  and  hecome 
rare.  Rarity,  a^  jfeolo^y  tells  us,  is  the  precursor  to 
extinction.  We  can,  also,  see  that  any  form  repre- 
sented hy  few  individuals  will,  duriiiif  fluctuations  in 
liie  seasons  or  in  liie  number  of  its  enemies,  run  a  trood 
chance  of  utter  extinction.  Hut  we  may  ffO  further 
than  this  ;  for  as  new  forms  are  continuiUy  and  slowlv 
Winjr  producwl,  unless  we  believe  that  the  number 
of  specific  forms  jfoes  on  perpetually  and  almost  iu- 
derinitely  increuhiriiyr,  numl)er8  inevit:ii)ly  must  hwome 
extnict  lliat  the  numl>er  of  s[M*<itic  forms  ha**  not 
indefinitely  increa»ed,  jreolotrk  shows  us  plainly;  and 
indeed  we  can  Hee  reason  why  they  should  not  hav« 
tiius  iucreaHed,  for  the  numher  of  places  m  Use  nohtv 
of  nature  is  not  indefinitely  great,— not  that  we  have 
any  uieauBof  kuowintj  that  any  one  retfion  has  a^  yet  pot 
itN  maiimum  of  8i>eiien       Probably  no  region  is  a^  yet 


100 


ON    THE   ORKilN    OF   SI'E(  IKS 


fully  St ocke«l,  for  at  tiu^C  aiK3  of  (iorxi  U(({)o,  where  more 
H[>«cieK  ot'  plaiiu  are  crowded  totfetlier  tliaii  in  any  otlier 
(jiiartiT  of  the  world,  some  foreigTi  plants  have  become 
uaturaliMMl,  without  causiiiir,  as  far  ;is  we  know,  the 
♦'xtin<'tion  of  any  iiativ*'^-. 

Kurthernuirt',  the  -jn'cies  which  are  most  numerous 
in  individuals  will  iiave  the  Itest  chance  of  producintf 
wittiin  any  triven  period  favourable  variationn.  \\  e 
have  evidence  of  this,  in  the  facti*  jfiven  in  the  second 
cha,>ter,  showing  that  it  is  the  common  s{)ecies  which 
atTord  the  i:reate«t  numl>er  of  recorded  varieties,  or 
incipient  species.  Hence,  rare  species  will  be  less 
•  juickly  nioditied  or  improved  within  any  ^^iven  perio<i, 
and  they  will  conse<juently  \>e  beaten  in  the  rrwe  for 
life  by  the  modified  desceudant«  of  the  commoner 
sixnies. 

From  these  several  considerations  1  think  it  in- 
eviUthly  follows,  that  as  new  species  in  the  c«)urHe  of 
tinu'  are  formed  throu^fh  natural  selection,  others  will 
become  rarer  and  rarer,  and  finally  extinct.  The  form* 
which  s^and  in  closest  comiMJtition  with  those  under- 
j:oiut'  modification  and  improvement,  '^"ill  naturally 
suffer  most.  An<l  we  have  seen  in  the  chapter  on  the 
!Stru:;;rle  for  Kxi>toncc  that  it  is  the  most  closely-allied 
forms, — varieties  of  the  same  species,  and  species  of 
the  same  ;jenus  or  of  related  genera,  which,  froni 
haviut:  nearly  the  same  stru(  ture,  con-ititution,  and 
habits,  jreiu'rally  come  inu»  the  severest  competition 
with  each  other.  Consequently,  each  new  variety  or 
sp«'cies,  durini:  tlie  projf ress  of  its  formation,  will  g-ener- 
ally  pre>s  hardest  on  it.  nearest  kindred,  and  tend  to 
exterminate  tluni.  We  see  the  same  process  of  ex- 
tcrniiii  ition  amoiiifst  our  (]omestic;iU>d  productions, 
throuirh  the  sele(  tion  of  improved  forms  by  man.  Manv 
curious  instances  could  l>e  triven  showintf  how  quickly 
new  breeds  of  cattle,  slieep,  and  other  animals,  and 
varieties*  of  fbtwers,  take  the  place  of  older  and  iiifj-rior 
kinds.  In  Yorkshire,  it  x  hi-<torically  known  that  the 
ancifiit  black  cattle  were  displaced  by  the  lou^-homs, 
and   that  these  '  wore  swept  away  by  the  "hort^horus  ' 


NATURAL  SELECTION 


101 


(I  fjunte  the  words  of  an  .lerii-ultural  writer)  '  m  if  hy 
Home  murderou-  postilence.' 

Iht-rryencr  (\f  f'hnrniter. —  I'lie  jtriiiriple,  which  !  li.ive 
lesitfii.iltMi  hy  thi^  t^rm,  i>  of  liieh  iniport.iiu-t*  on  niv 
theory,  and  expl.-iiim,  a«  I  helievo.  wnpnil  important 
tarts.  In  the  first  phirp,  vari»>tiex,  ••vpti  strnMirly- 
iriarkrd  onofl,  thouirh  ha\iiii:  somewhat  of  the  chanicter 
.if  s|>e<ies-  as  is  «hnwn  hy  tlie  luipt'lcHs  douht*!  ii;  iiianv 
I  ;ise««  how  to  nmk  tiieni-  yet  rcrtiiiiily  differ  tro-ii  eacfi 
other  far  less  than  do  jr<"»<l  and  distinct  sjiecies.  Never- 
tlieless,  accordiriif  to  iii\  view,  varieties  are  species  in 
the  process  of  forrnatinn,  or  are,  as  I  have  called  tliem. 
incipient  specie,s.  How,  then,  does  the  leaser  dirferencc 
tH'twt'C!!  varioti*";-  become  auirniented  into  the  trre.iter 
difference  l>etween  sj>ei'ies  -  That  this  does  haliittially 
liipi>eM,  we  niiist  infer  from  most  of  the  innumerahle 
speces  throutrhout  nnturf  preseiitintrwell-m.-irked  differ- 
fMice>»  ;  wh«>reH.s  varieties,  tlu'  sipfMised  prototvjM-^  and 
parents  of  future  well-marked  «{)eries,  presefit  slight 
and  ill-<letine<l  differenee-i.  Mere  chance,  as  we  may 
lall  It,  iniirht  cause  one  variety  to  differ  in  some  char- 
acter trom  its  parents,  and  the  offspring  of  this  variety 
airain  to  differ  from  iL«  parent  in  the  very  same  character 
and  in  a  g-reater  decree  ;  hut  this  alone  would  never 
account  for  so  habitual  and  lartre  an  amount  of  ditfer- 
«'nco  an  that  hetween  varieties  of  the  same  sj)ecie8  and 
spe<'ie.s  of  the  same  eenus. 

A.S  has  always  been  my  practice,  let  us  seek  liirht  on 
thi.«  h'ad  from  our  domestic  productions.  We  shall 
here  lind  soniethini;  niialo^'ous.  A  fancier  is  struck 
Kr  a  pijreon  havinjr  a  i^lij^htly  shorter  })eak  ;  another 
ti.'iCier  iH  struck  hy  a  piijeon  havintr  a  rather  lonircr 
><vak;  and  on  the  acknowlc-di^ed  principle  that  '  fanciem 

00  not  ,ind  will  not  admire  a   fiifdium   standard.   i)ut 

1  ke  extremes,'  they  both  no  on  (as  bas  actually  occurred 
Aith  tumtder-iiiifeoiis)  choosirm  and  J>reedin.ir  from  l'!r<!s 
^vith  lonu'er  .and  loiiijer  be-aks,  or  with  .shorter  a:,d 
short*  r  ^>eaiiH.  Airain,  we  may  suppo.-e  that  at  ati 
'<arly  period  one  man  preferred  swifter  hor*Hs  ,  nnotuer 


]02 


ON    THK    <»IU(;iN    (»K    sPK(  IKS 


'^' 


"Lrniijrt^r  .irirl  rnnre  luilky  Jiorsps.  rii<M';iriy 'liffcretice* 
would  b»'  very  fcliirlit  ;  in  ♦he  rnurs*'  of  time,  from  th»i 
oontiiuie<J  ^<  '..''tioti  of  «vrif>«'r  tHir-cfS  hy  kmiiio  hrff-iors, 
aiiil  i)t  stro!itrt»r  onc-J  *>v  '>tii»>rx,  t!i»>  lii'ffrf'm'p^  would 
''OCOTno  t»T»»at»»r,  atid  \»viuiil  t't*  rinUvl  -i«4  t'ormin^  two 
ont>-i>r(>««(l-,  ;  fin.tlly.  jiAcr  the  l.ip-^c  of  c«'riturips,  the 
«nh-hr('o<l-i  would  iMvonip  rotivortrd  into  two  w«ll- 
extahli'^hptl  aiicl  ili^trict  hn>«vlrt.  As  the  diff»>rpiire9 
gjowlv  'H>c()rm>  irrjvitcr.  the  inferior  anim.ii.-  *ith  inter- 
mtHli.'ite  I'haract.TP,  tiomtr  iifithnr  very  swift  nor  very 
gtroiitf,  will  have  hoeu  iiOiri»'i"t<Ml,  and  will  h.ive  tendoil 
to  di'>a[>[ppar.  Here,  then,  we  wo  in  man's*  prodnrtioni 
Hie  a«ti«in  of  what  may  l>e  r.iiieil  the  principle  of  diver- 
ifenro,  caiiHintr  ditfi-retifOH,  at  hrwt  barely  appreciahle, 
steadily  t<">  increase,  and  the  t»re«Mis  to  diverire  in  -hir- 
icter  hoth  rrom  (vach  other  and  from  their  common 
parent, 

Hut  how,  it  may  ho  a^^ked,  can  anv  analntrouM  prm- 
C';ile  apiilv  in  nature.'  I  *>elipve  it  cai,  :ind  d.'H»x  ap|iiy 
most  elhiit'iitlv,  from  the  ^^imple  cifcum'-taru'e  that  the 
more  divermiuvi  the  descend. mb}  from  r.nv  one  P[)ecie8 
hecome  in  ptnictiire,  con-titntion,  and  hahiw.  hy  so 
niinh  will  thev  he  hotter  »'iri}>led  to  ^^ei/e  on  many  and 
widely  d-.versitied  places  in  the  polity  of  nature,  and  40 
be  eiiahled  to  ir.c.ease  in  numherp. 

W'p  <'an  clearly  <re  this  in  the  rase  ot  animals  with 
fiimplo  haSirs.  lake  the  case  of  a  carnivorouij  ..uadru- 
ped,  of  which  tl  e  numher  that,  can  i>e  supported  ui  any 
cniin*r\  h.'is  lontr  ''u,'"  arri%e  |  ?it  i^^  tuil  averr»t:e.  if  its 
natural  powers  ot  increase  he  allowed  to  act.  it  can 
Bucceed  in  iiicreaxinif  (the  country  not  underffoini;-  any 
chantre  in  it«  ••onditions;  only  hy  its  varvine"  descen- 
dants seuinif  on  places  at  present  occupied  hy  other 
at'.inials  r  some  of  tli.»^ni,  (  t  instance,  ^leine  enalde«i  to 
feed  on  new  kinds  of  prev.  either  dead  or  ih-.e  ;  som« 
inii.ahituiii'  new  stations,  chmhing'  trfe«.  tre'j'ientinif 
water,  and  some  perhaps  h«'comin<f  le~><  i-arnivorouji. 
1  he  more  dntTsitied  m  hati:ts  ari'l  stri;cture  thf 
dcM«cendants  of  our  carnivfirous  animal  t>ecame,  tha 
more  pLice'-  thev  adiiIiI    he  enafded  to  -vcupy.      ^Vh** 


1 


^ffe^^i/v-  lL^l^M.J^:^2^m£:!^^mk 


NATIKAI.   SKI.K(T1()\ 


103 


applies  to  <>•.»•  ;uiir»ril  will  npi  Iv  t!ir()ii/i!i"it  al!  l  in« 
to  .'ill  .iiiimnU  tli.if  iH,  it'  flicy  vary-  t(»r  (>t^t'rvri^e 
natur.'il  >««'Ie(  tiori  crin  flo  TinthinLT  So  it  wi'l  >«c  with 
plai'ts.  It  hnt  Ix'tMi  t'vjit'nniciitallv  j»r<ivt»<i,  t)>at  it"  a 
plc»t  of  groiiml  !>»«  «i<nvii  with  oiio  ^p^'rit"*  of  ifr^t^M,  and 
a  similar  pint  1>«>  <(i«  n  «itli  v««\  cr.i!  ijistiu<t  potior* 
of  irra^^os,  a  i/rt'ati'r  luiiiiluT  of  pl.intfl  ami  a  greater 
weiirht  of  dry  lierlia;;'**  can  tlm>4  lie  raisp'l.  I  'le  ■vima 
ban  tx'eii  found  to  Imld  trootj  wlipn  tiriit  f)no  vnrioty 
and  tlit'fi  s»'\<'ra!  rnixod  varu'ti«»8  of  wlieat  havi'  ht-f^n 
sown  o!i  equal  spaces  of  iiroiind.  Uciicc,  if  any  one 
operios  of  yfa**'*  wre  to  gn  oti  varvinc,  and  tliose 
varieties  were  oontinjially  ^elertcd  whicti  ditft'red  from 
each  other  in  at  all  the  rt;ime  manner  as  di^lirict  specien 
«nd  jfenera  of  trrasses  differ  from  each  other,  a  {greater 
numU>r  of  individual  plants  of  this  spe<'es  of  j^rasH, 
incliidintr  its  modified  d»'sceiidafit-',  "oiild  .succetxl  in 
livirnf  on  tl'O  satne  p'ece  of  irn)Ufid.  Atid  w(>  well 
know  lliHt  each  site<ies  atid  e.ich  variety  of  ^Tnss  is 
annually  so\vni;i-  almost  countless  seeds  ;  and  thu^,  u 
it  may  he  ^aid,  is  strivifijr  its  utmost  to  incrt-a-e  it<t 
numhcrs.  <  (tnseiiuetitly,  1  cai'tiot  douht  tli.it  in  the 
-nurse  of  mativ  tlu.uvuids  of  tret^eratinns,  tf'o  r.Hvst 
distinct  vanet;cs  of  any  otie  ppecies  of  trr-i-"*"  «■  ilj 
always  have  the  l)ost  cliatice  of  succecdirssr  ars'l  oi  m- 
cr«'.'s'tii;  in  niirnlKT".  atid  tlius  of  siipplanti/;:/  tl.*'  less 
distinct  \an»'tie-i;  ami  %arii'ti>'s,  wImmi  rendo'ed  very 
di-t'iict  from  each  oth»'r,  tak<>  the  rank  of  «j  *'c;es. 

'Rie  truth  of  the  pr:ti<  ip!e.  thtt  t!ie  t:re?t'.--t  amount 
of  life  can  he  supported  hv  ^ireit  di^ersiticitinn  of 
structure,  is  seen  uide"-  many  natural  circunistafuTS. 
In  an  extremt'ly  sm:ill  ar»'a,  especiallv  if  tre«»ly  ojicn  to 
immitTat.on.  and  wh.'re  t!ie  contest  h«'t«eer!  iMdi\iil')al 
and  individual  must  he  severe,  we  a!wav«  find  jreat 
diversity  in  it,s  inliahitant.s.  For  instafue,  I  found  that 
a  piece  of  turf,  thrt'c  f«*<^t  hy  fieir  in  «i/e,  whifh  had 
(<<^en  ei[>ose<l  for  m.anv  yearn  to  exaitlv  the  .same  cf)u 
'iitions,  supported  twenty  ■species  of  piints,  atid  thefie 
oelonired  to  eijrhteeii  irvnern  and  to  eii:lit  orders,  which 
shows  how  inuch  the-e  plants  differed  from  each  other. 


104 


o\   ruK  oiu(;i\  OF  spKciKs 


So  it  iH  Willi  tlip  pl;iiit«i  and  •ii-«>cU  on  ^mali  nnd 
uiiifonn  islet-;  ;  and  so  in  mn.ili  |MitiiiH  of  frosh  wafrr. 
Knrriiers  find  that  tliov  cati  miv-*'  mo>t  food  }>y  a  rotation 
of  iilaiits  hcloiiiririf  to  tlo-  most  different  ordon»  :  nature 

tolliiw-.  \\]ia'  in.i}  l.c  .anfi!  ;i  >iinu lt.ln4•.lu^  tntaticn 
Most  of  tlic  inini.iN  .ti;i1  p!  iMt.s  wliirh  li\«.  clo-p  round 
aii\'  small  jiu-.e  of  trround.  could  liw  on  it  (supfiiisirn: 
it  not  to  ),.'  in  any  ua\  jn'<-  iliar  in  iN  naturf),  .md  may 
In*  said  In  In-  -tnunL'  to  '.].,•  utniuvf  to  !i\«'  tinTi- ;  iiut, 
it  is  sfon,  tliat  wiicre  tlicy  cnino  into  tlif  do-.'.:  com- 
prtitiori  uifli  carfi  otli.-r.  tht*  ;i.hantair»"<  of  div»>rsinc.i- 
tion  of  HtriK'turr,  witli  tin-  ncconipanyiiitf  dir'^f  ■•fn  »■>.  of 
Kaliitand  cnnstitution .  drfcrrnin*'  that  tlie  Mili.ilntant"*, 
\vh!fh  thurt  jostle  ea. d  otlicr  most  .jo-.-lv.  f.liai!.ii-.  a 
irrnrral  nilp.  l>»•l.iM^''  to  what  « .•  .•.ill  .i::f.T(>t,t  (.'cucra 
and  orders. 

Die  -.line  priiiri[.!e  i>;  .een  in  the  natiir,'ili«.a-;on  of 
plants  lfir(Mi::ii  i):,iu>  ;i_eiicy  in  foroitrn  lands.  It 
mitrht  liave  l-een  .-vpected  that  the  jdauts  wlm  h  have 
su'-C'eded  in  lioio-nina'  naturalised  in  anv  land  would 
jTonerally  have  l.een  clo-ely  allied  to  the  indiffenes  ; 
for  tlu'.-e  an-  roinruoiily  looked  at  as  speciallv  created 
and  ailaptod  for  their  o.^n  rountry.  It  tnitrht,  also, 
p«'r':aps  ha\.'  heeri  expected  that '  naturaliM-d  pl.mts 
would  h.'ive  !  eloiiifed  to  a  few  jrroups  more  especially 
adafited  to  certai-i  stitions  in  tlu-ir  new  homes.  Hut 
tho  case  is  verv  o  ffercnt  ;  and  Alpli.  I)e  <  .uidolle  tian 
well  remarked  in  his  irreat  and  adniira(d<>  work,  that 
th.ras  {jairi  l.y  naturalisation,  proportionally  witl;  the 
numl'er  of  the  native  trcnera  and  >jKM:es.  far  more  iu 
new  trenora  than  in  new  species.  'I'ii  cive  a  -int'le 
in-tance:  in  the  la.st  edition  of  |)r.  .\s,i  drav's  Manual 
o/ffir  Horn  of  thr  Xorthrrn  f'nif'il  SfHtp.\,  2<"><t  natunlise*! 
nlanl-  are  enutneraled.  and  these  helont--  to  Id::  !,n-nera. 
\\'e  thus  see  tiiat  these  nat iirali-cd  plants  are  of  a 
hiirhly  diver.-iti.il  nature.  i'hey  diifer.  iiiorto\er.  to 
a  hiTire  extent  from   tlie  indiirenes,  lor  out  of  tae  102 

irAr  1  «ir>u        T.it     ]^.^.       il....,       !jiiV       .....  ^_..      „_,.      .       i      ^V~  1 

^T- .-^     ,,..     ,.    --     ..;::-.;;      ....    -tritf;.;    it;t-     :     r:      ;::t-r:-     it;;;; 

t^eriouti,  and  thu->  a  lar^re  propor'.ional  aoii.iiui-  i.-  uiade 
io  the  ct'uer.:  of  these  Staic 


NATL'llAL   SELECriON 


]iV> 


Br  (•(•nxHieriii:;  thf  natiir»«  of  tin'  itl.iiiU*  or  airmal* 
wliiih  hnvo  t<trin:irl«''1  Huftc-i^fully  with  tlip  itulici'iie* 
of  .iiiv  country,  a'ld  have  tln-ro  hrcorne  n.itiirili«r<l.  wre 
mav  jrain  Homo  (•rii<l»>  nlra  in  wliat  rnautipr  <Mtriu'  ot  tlie 
n.ituj'ji  would  }i.i'.o  to  i<«>  rii'i.l  :;cil,  iti  or>ltT  to  train  \i\ 
iilvantaifp  ovpp  tlip  otiipr  rlative^  ,  and  «»•  may  at  l»'<Kt 
satt'ly  iiifjT  that  divor-itiration  <>f  <trii.  tur«'.  aniotiiit- 
Mii/  to  iM'w  i:«'neric  ilirienMicox.  would   t-f  iirot'.t.iM«  to 

tloTll. 

Ilif  adv.intau"'  of  divfr-iificrion  in  tlio  inh.iluf.inifl 
of  th<'  same  rivi"ii  is,  in  fact,  the  -^arnr  as  that  of  ti,^ 
,divMo](i::n-.il  dni.-ion  of  iahour  in  tho  npirans  of  ftie 
-anu>  mil; .  idual  l«o<lv  a  suhjprt  so  well  clu.  l-i*#>'i  1., 
Milhp  |-..i.^ards.  No  (ih  vsiuintn^t  douht>  that  a  -imiiacti 
I  I  ipted  to  diircut  ve^»'taiil»'  mattt»r  alone,  or  lU'-h  alone, 
ir.iws  most  initriment  from  th^sp  suh^'aiuj's.  >o  in 
■h»-  ifcneral  »'cnnMtiiy  of  anv  iaml,  the  rn<>rt«  v*i<|f]v  \iu\ 
[•••rfpitly  tli«'  animals  ami  plants  arc  <livfcrsiii«»d  for 
(li^orriit  ha'iit-i  ot  jifi-,  >■<>  will  a  trn-.iter  ncnilu'r  of 
indi\i(iuals  h»'  cajiriKlp  of  flioro  supportiti:.'  tlu'riis»«K»-f<. 
A  Het  of  .ininiafs,  with  tlieir  ori;ani<»;ttioti  t)ut  l;lt!p 
dnorsifie*!,  i  ould  hardly  compote  witli  a  set  mor*' 
p*-:  ;'(•(  'Iv  divcr^ifiod  in  structur*'.  It  ni.iv  he  doui»t«'d, 
for  HisUmi-e,  wlictlier  the  Australian  marsiipiaU,  which 
arc  divided  into  j^-roups  ditferiisiT  hut  liitle  fmrn  eacii 
iithtT,  and  u'ehly  rcprt'^fliuinir,  as  Mr.  \\  itrrliouse  and 
nthcrs  have  remarked,  our  carni\orou«,  n.minant,  and 
rcHiOnt  mamnials,  could  succes.-fuliy  compete  with  these 
well-pronounced  order-.  In  the  Australia!]  mamrnals, 
we  -ee  the  pnn  ess  of  <iiversifn  ation  in  an  early  and 
ii)'  oniplete  st;itfe  of  development. 

.\fter  the  foreirointr  (iirtcussi'Ui,  which  oucht  to  have 
hei-n  much  amplilied,  v\e  may,  i  'hiiik,  assiime  tliat  tije 
inditied  de-cendantj*  of  any  one  cjK'cies  w  ill  succeed  hy 
-o  ruui'h  tlie  hetter  as  they  beci.Tne  more  ili\er->it.ed  in 
struciurc,  and  are  tlius  e!ial>le<]  to  en<To.n  h  mi  placeti 
>ccu|iied  hy  other  hein;.'s.  Now  let  us  !»ee  liow  ihii 
ruitipie  of  heilefit  btJiHji  deiivf-d  fruni  d;vpr(,riii«  •>» 
.  haracter,  coni!>ined  w'th  the  principle;-  of  natural  neleo- 
tior  and  of  extiruiiou,  wiU  teud  to  act. 


!  fir, 


•  'N     !  UK    OlUlilV    (>h    M'K*  IF> 


f 


HiH  nrcompaiivinu'  fiii'/ram  ■.*ill  ,-iid  ^m  in  uii.Iir. 
-tuilun:  fliijt  raflitT  |t»'r|>l«'itirip  Huliu't-t.  IjpI  .\  tn  I, 
r»>jir»'-fMl  th«  Mjir-ifM  (»t  n  j^rrm**  l;iri.'f>  in  <\n  uivri 
•uuMlry  ;  lliniHO  xpi'iii's  .iri»  "ijpiiu^iMi  t  >  rc-pfniiip  p.ich 
>lhfr  iti  iiru*'|M.tl  iIi'ltim*-.  n*  is  so  ;/»'r)i>rr»!lv  fho  i'.'Imc 
M  n.ifiiro.  nnd  m  h  r»'[i'-t-.«'!iT»',|  ni  tfip  (h.i;rram  i»v 
•ill*  IfttiTs  •itiiiKliiiL'  at  UM»'>|u;il  (li«UiiireH.  I  ha*f»  -aid 
.1  iJirtri)  irt'tiim,  iHTijiisfl  we  have  **t'«':i  in  the  -»'<i»n<l 
rhipter,  fhrit  on  an  ;ivt'rni.fo  nuiro  u'  t|io  njKM-ies  of 
i.i'-ife  ceripra  vnrv  th.in  ..f  -mall  jr»Micr:i  ;  ;iriii  tti»>  varv- 
.•■,j  specu'r.  iif  the  lar^rf  CMt-ra  pn-jcnt  n  trri- itiT  nuin*>«^r 
W  varu'tien.  U  e  have,  hUd,  ^..,.(1  that  tlie  «ipf(  io<!. 
'*iiich  art!  the  rnminorie-Jt  ami  tin*  niost  h  )ilelv-<lif1uHe<l, 
varv  n\<>ri'  than  rare  -pfcies  w;t[i  ri'st rictt-d  rin::oH. 
Let  (  A I  'le  a  fdtnmdn.  widflv -diffused,  and  var\ mif 
Hpe<-;e'<.  h.'i(cii.'Uiu'  to  a  treruis  lar^re  in  its  own  i-nutiirw 
The  little  fan  of  di^eririi'i;  dotteii  lirieN  of  iineijual 
letJt:»h-<  prnri»ediinf  from  i  A),  mav  represent  its  varvinjf 
.iJi-prinir.  I  he  variaMo:m  are  Mi[>po-ed  to  U»  e\t  rernelv 
liiiht,  hut  of  tlie  nioNt  'iiverHiticd  nature;  thcv  are 
not  Bupi>o<!e<l  all  to  appear  mmnltaneoimly,  hut  -dten 
after  Ion;;  intervals  oj  t!:iie  ;  nor  are  ^)\t>v  all  supposed 
•o  endure  ^or  e'lual  periods.  (»ril\  those  variations 
whi<'h  are  in  some  way  proiitalile  vriii  be  preservtMi 
or  nat:jrally  -•iliM'fed.  And  hfre  the  importance  or 
tiiB  i)rin<'iide  of  henetit  \>oiii!;  derived  fro!,i  di\  enro-icp 
if  fhararter  romeH  m;  for  this  wili  teneraliv  lead  to 
llie  most  different  or  diverfi-ent  variations  (rep-,.>;eiited 
hy  tfie  outer  dotted  line*;)  h(>i:iL:  preserved  and  aeeu'iiu- 
lated  hv  natural  seleition.  W  hen  a  dotted  line  reaciies 
one  of  the  hon/nntal  lines,  and  is  there  marked  \>v  a 
sinall  nu!ii'i«Tt"i  letter,  a  sufhciei'*  amount  of  variation 
IS  supposed  to  hav©  heen  aecumulated  to  ha\e  formed 
1  fairly  weU marked  variety,  xuidi  as  wcvild  he  thou;rht 
Torthy  of  reeord  in  a  .sv«teniati<"  work. 

Hie  intervals  hetwet'ii  tlie  iion/ontal  lines  in  thi- 
liaj^ram,  may  represent  earh  a  thous-and  jrenerations  , 
nut  <t  would  have  ^n-eri  hetter  -f  r:uh  hi.-'  rrpre.-<',;tp<i 
ten  thous.Tud  i:»^nerations.  .\tter  a  thou^aiid  t't'iiera- 
'.oa>.  speoies  i  \!  is  supposed  to  have  produre*!  t*o 
-  'iim^raTn  at  the  ■^•mmenoement  of  rolunu 


MB 


NAll  HAL   SKr.F.CnoV 


lf>7 


fairly  wel!.m.-irk««<l  vririHtie.-*,  ii»nn«ly.  u'  ami  m'      n1t•^e 

two  ^  :»ri»'t'«"»   will    tfctUT-ll!  ,•    rntitiliilf    to    '►«•   rx[i<»>»M|    fo 

'.ho  name  <'on<litioiii  which  m;i(i»>  t\'*"r  pirfnt*  vani  ne, 
*nil  tlie  tiMiil«Mn"y  lo  v:»ria''il!ty   i-*  in  itM«'U  h«»n><iit.irv, 

roiix*''!'.*'!.!  !•,     tlii'V    will     ti-ti'l    ♦(!    ViiTT,     HTI'J     •:♦*'»•'     »lU      tO 

vary  Iti  ticariv  iho  "i,tni«>  rnatinnr  as  th»':r  jwircn'H  v.iri«'(l. 
Moreovor,  tht'xetwn  variolios,  U>irirf^o:ily  ^iik'li'iv  timiii- 
fird  rnrm-*.  \^ill  t.iifl  to  irihtTit  Ihone  ailv.tiit-i;.'*'-*  whwh 
.nfi<le  tiii'ir  [>.iri'iit  '  A  i  rnorp  numermis  th.iii  iim^t  uf' 'he 
oth»«r  inii.iliitAiit'*  nt  th«  samp  r<iiiiitpy  ;  th»»y  will  likt>- 
wi-jj*  prirtikf  of  thii^«  nupr»«  j^orirral  aih  aiit.Vf'  wliich 
ma-lf  the  kfciiiM  tn  wiiii  h  tin*  [>.ir«>rit  -i'«''i»'-i  l>»M(>nL't''l,  » 
lartfi^  ueiins  in  its  (i«ii  roiMitrv.  A'ul  thi'^n  rirriini- 
jtaiifos  w»<  tv'iDW  t(»  \to  fav4i!ir  iiiirt  to  the  {)rf>«iuct:oM  <it 
now  variftifs. 

If,  thou,  llu^»)f»  two  varioHps  he  vrjriaWo,  th»»  mo<it 
oivcrjfoiit  ofthoir  v.iriHtioiis  will  ct'nerilly  ht>  pr»'»<'r»tMl 
ilurui;;  tlu'  rioxt  thoii<ci!iil  krciitT'itioiis.  Ami  aft»r  (hi^ 
intrrval,  variety  a'  is  supposed  in  the  fliairri'n  to  have 
produce'!  variety  '/*,  winch  "aiU,  owiijj  to  tlie  |>ruuMjde 
of diverirt'iice,  dif'»'r  nior«  from  (A)  tnan  did  variety  a'. 
Variety  m'  in  *iijij>oHe  1  to  have  prod..  I'd  t*o  vari»'ties, 
riarneiv  m'  and  k-,  ditferin^  troin  each  other,  and  more 
ionsidt'ra'dy  from  tlieir  common  parent  (A).  ^^  e  may 
ontmiie  t'le  proi-esH  hv  Himiiar  ste[>s  tor  any  li"iirth  of 
lime;  Home  lit  the  varietie«^,  alter  each  Lhousa'il  «;t'ner- 
atioiiH,  pro<j  iciny  only  a  siinrle  variftv,  hot  in  a  inore 
and  more  'TKxiihed  condition,  ■<ome  ;  ro<lticini.'  t**o  or 
t}ir»»e  ■  arit'iiex,  iruJ  ■jome  taihriif  to  produce  any.  I  hm 
the  varieties  or  m"<lit'ied  dexrendant.'*,  pro<'eeding  from 
the  "'ommofi  Marent  (  A>,  will  trenerallv  co  on  i;.cre.i<injf 
in  numh-r  and  diveriTiiitr  ni  character.  In  the  di.iL'ram 
the  proce.-«-  H  rcpre-fit.d  Mp  to  the  ten-thoijw.indth 
renerat'oTi.  and  iinuer  'i  fondensed  nrui  •iimniificd  term 
up  to  the  tourt  •♦•ii-tiiou-vitiii'h  treri^ration. 

Hut  I  rrui-st  liere  remark  that  1  do  not  sippo*^'  that 
the  proce-y  pv'T  troe<^  on  '•o  re^trularly  an  i«  repre-ient./'d 
ill  liin  di.'urnim,  Tti(iii:.'ii  m  ii>«>it  maii-?  »«iiti»*whai 
irreirular.  I  am  :ar  from  tfiinkitiif  that  the  mo«t 
divergent  varieties  wili  invanahiy  prt'v.iiland  multiply: 


^f^ 


108 


ON   THE   ORIGIN   OF  SPECIES 


a  medium  form  rna\  r)ft(Ti  Innjr  oiidiirn,  arul  may  or 
may  not  pnuliirp  mon»  tli.iii  one  modified  dt'soeiidant  ; 
for  natural  sele«;tion  wnll  always  act  accordintr  to 
the  nature  of  the  places  which  are  eitlier  unoccuiiii-d 
or  not  perfectly  ocruf.ied  hy  other  hoin^rv  ;  and  tlii-* 
Will  depend  on  intinitejy  complex  relations.  Hut  a- 
a  general  rule,  the  more  diversified  i-i  structure  the 
(lescpfidants  from  any  one  species  can  he  rendered,  tlie 
mor*-  f daces  they  wiii  l>e  enal)le<l  to  seize  on,  and  the 
more  tlioir  modified  yrnizt'ny  will  be  in.-reased.  In  our 
diaLTam  the  line  of  Hucc(>sKion  is  hmken  at  retrular 
intervals  hy  small  iiuml><T,.,i  letters  inarkin^.'  tlie  su<;- 
casive  forms  uhirh  liav.'  l>econie  -ufficientiv  distinct  to 
he  recordeil  as  -arielic-.  Hut  the'-e  hreaks  are  im,iiri- 
nary,  aii(i  mii,'i.t  have  i.ccn  in<ert<-d  aMy\\)ii.re,  atler 
intervals  loritr  enoutrh  tt)  liave  allowed  the  accumulation 
of  a  ( iinsideraide  amount  oi'  divertrent  variatidii. 

A-  all  the  modifiotl  descendant.s  from  a  common  and 
>vid»>ly-d  iff  used  spocies.  helotifing-  to  a  larffc  trenus.  .vill 
tend  to  (r;rt;ike  of  the  s.-inie  advantaires  which  made 
their  parent  successful  in  life,  they  will  ^eneralh  t^o 
on  muitipiyinjr  in  rnimhor  as  well  as  divertring  in  char- 
acter •  this  is  represented  in  tiie  <li;urram  hy  the  several 
divprirent  hrani-'ies  oroceedii.r  from  (A;.'  'Ilic  modi- 
fied off^prine  from  the  later  and  more  hii^hly  improved 
{'ranches  in  the  lines  of  descent,  will,  it  is  prohahle, 
olien  take  the  place  of,  ai,d  so  destroy,  the  earlier  and 
les*;  improved  branches  :  this  is  represented  in  the  dn- 
sram  hy  some  i)f  the  lower  branches  not  reaching  to  the 
upper  horizontal  line*,  in  some  cases  I  do  not  doubt 
that  the  process  of  modification  will  be  confined  to  a 
Hini^le  lint-  of  deM-ent,  and  the  number  of  the  .le- 
«cendanb;  will  not  be  in<-reased  ;  although  the  amount 
of  divergent  modification  may  have  l)een  increased  in 
?iie  riucccs--vt'  ijen.T.iMons,  Thig  csis<»  would  he  repre 
Konted  III  the  ilijitrraju,  if  all  the  lines  proccj-diiiu 
from  (,\)  w^re  remove<l,  exceptiriL'  tliat   from  a'  to  *;'". 

••1    .;i^   r.-.;;:r   ".ij.,    : : :  T    ;:;:.;;.<;".    i.r;i'    r.jTi^iInii    TaOt^  iior.-'tj 

Hid    Knt-'iisli    pointer   hav«    apparently    b<jth    g-oiie    ou 
■:*ii»nriv     .hver^'iiiir     in     oJiaracter     from     their    original 


NATURAL  SELECTION 


109 


stockH,    WTih(»ut  either    having    g-iveii    OJf    any    fresh 
branchcH  or  races. 

After  ton  tliou^aiid  tr^'nerations,  sinvTies  (A)  ix  -ui>- 
pMM'd  to  have  {)r()duoe<l  three  toriiK,  a"',/'^,  and  v<*", 
whirh,  from  haviiitj  diverged  in  character  durint:  the 
puccessive  )Xt?iit*nitiitns,  will  have  come  to  differ  larirely, 
hut  perhaps  urie(|iially,  from  each  otht-r  and  from  their 
common  parent.  If  we  suppose  the  amount  ofchantf:e 
between  each  horizontal  line  in  our  dia;rram  to  Iw 
exces-sively  <njall,  these  thriK?  forms  may  still  he  only 
well-marke*!  varieties  ;  or  they  may  have  arrived  at  the 
douhtful  catetrory  of  suh-spe<-ie«  ;  hut  we  have  only  to 
8uj»|«»se  thf  steps  in  the  proce*w  of  modifi'-ation  to  l>e 
more  numerous  or  irreater  in  amount,  to  convert  th»'se 
three  forms  into  well-<letined  s;»ecie,s  :  thus  the  di;Hrram 
illustrates  the  steps  by  whic'i  the  small  ditferences 
distinifuishinc  'arieties  are  increased  into  the  larj^er 
ditfereiifes  di>ti'.irui.-hin;r  sj>e<-ie<.  Hy  (ontinuintf  the 
same  proces.>'  for  a  gre^iter  numl)er  of  t'^enerations  (as 
shown  in  the  diiurram  in  a  conden.sed  and  simplitied 
manner),  wo  ^jet  eitrht  si)ecies,  marked  by  the  letters 
between  a'*  and  m'*,  all  descended  from  (A).  Thus, 
as  1  believe,  s[)e«'ies  are  n\ultiplied  and  t^enera  are 
formed. 

In  a  lartje  jfenus  it  is  probable  that  more  than  one 
sjKJcies  would  vary.  in  tlie  diagram  1  l^ave  assume<l 
tliat  a  second  species  (I)  hii-s  produce<l.  by  analotrous 
steps,  after  ten  thousand  jjeneratiens,  either  two  well- 
marked  varieties  (v^"  and  z  '^';  or  two  species,  accordinir 
to  the  amount  of  clinuire  supposed  to  l>e  represent*,*! 
l>etween  the  horizontal  lines.  After  fourteen  thousiin.! 
generations,  six  new  species,  marked  by  the  letters  ;<^* 
to  r'*,  are  suppostsl  to  have  Insen  produced.  Iti  e;i<-h 
^enus,  the  specie-;,  wliicli  are  already  extremely  dif- 
ferent in  character,  will  trenerally  tend  to  produce  the 
yre^itest  numbi-r  of  modihexl  descendants  ;  tor  these 
will  have  the  best  chance  of  tillintr  new  and  widely 
different  [daces  mi  the  polity  of  nature:  hence  in  the 
diag-ram  I  have  chosen  the  extreme  species  (A),  and  the 
nearly  extreme  species  (1),  as  those  which  have  lartrely 


IK- 


ON    IHh    olllGIN    OK    M'h(  IK.'- 


m  i 

4n 


I 


vancil,  aiiii  ii;ive  jrivfii  rise  to  new  vari»'ties  ai;d  >[K»ci<»h. 
Hie  other  nint'  -j.«-cu's  (liiarkeii  hy  ciijii'iti  ieittTy)  of 
our  oritiiiai  ^tMiii>,  may  for  a  loiitr  period  continue 
to  transmit  una'tt-red  desciMni  mt- ;  and  this  is  hljown 
in  thi'  (JKitrrain  li>  the  «lott»'<i  lineH  not  pralontrt'd  lar 
upwards  from  want  of  s|Kic'e. 

Hut  dunii::  tiie  pnK,'est  >,(  niodilication,  n>[)rehenu5<l 
in  th(>  dia::rani.  aiiotlier  of  our  pri:..',i.i»'.s,  namely  that 
of  extinction,  will  have  playtMi  an  nnjhprtant  part.  Ai 
in  e.u  h  fnlh  stocked  rountry  natiirai  seh-i-tion  necen- 
K,iriiy  acts  uy  ■  no  heiected  form  ha\ine-  some  advanLaice 
in  tlie  str(iir;:u'  for  life  over  other  lurms,  tinTe  *iil 
h«!  a  ruiistai.l  'endency  in  tht>  improved  d«-ie:i(lant.s  ol 
an\  one  specie  to  supfiLint  and  e  erriiinate  ui  ea<'L 
sL;i-f  of  descent  their  pri-decessors  and  their  oritfinal 
parent.  lor  it  should  he  remernherod  that  the  com- 
pel iuon  will  ir,.iierally  i)e  most  severe  lietv*e.-i] 
tliose  forms  which  are  most  nearly  related  to  eaii, 
other  in  iiahits,  oinsiitiition.  and  stnuture.  Hence 
ail  the  intermediate  forms  i.etneen  tiie  earlier  and 
later  sute,s,  that  i«  het\*een  tne  less  and  more  improve*! 
Ktate  of  a  species,  us  well  as  the  ori;final  i>;uent-specie8 
itself,  .vill  jjenerally  tend  to  he<ome  exlmcL  t>o  it 
prohahly  will  Ikj  with  many  whole  collaU'nil  linen  of 
descent,  winch  will  he  cornjuered  hy  later  and  improved 
lines  of  de.scenL  If,  iiowever,  the  modihed  otisprin^'  o/ 
a  sjH'cies  net  into  some  distinct  country,  or  In-come 
quickly  ada()ted  to  some  (juite  new  station,  iri  which 
child  and  parent  do  not  come  into  comjH»tition,  hoth 
may  continue  to  exi.st. 

It  then  our  dia^jram  be  ahsumed  to  reprc-cnt  a  con- 
siderahle  amount  of  modiJication.  species  (A)  and  aij 
the  earlier  varieLietj  will  have  tn'come  extinct,  havin*? 
heeii  replaced  hy  eiirht  nj»w  spt'cie-t*  (a'*t'j  yn^*)  \  and 
(1)  will  have  been  rephiced  by  8ix  (n '♦  U)  z")  new 
species. 

Hut  we  ma\  ^o  further  tliau  this.  'llie  ori)final 
8pe<  les  of  our  penus  were  supposed  to  renemUie  each 
other  m  uiiequ.il  detrree»!,  a**  is  so  penerall)  tlie  c^se  in 
nature  ;  specie.s  (A)  beiufi-  more  nearly  reLiurd  to  li,  C, 


NATIilAL   sKLKCnoN 


m 


and  I),  than  to  the  other  spe<'ie«  ;  and  s|K,'ties  (I)  more 
toli,  H,  K,  L,  than  to  the  others.  I  hese  two  fipei'iex 
(A)  and  (I),  were  also  supjioM-d  to  he  \ery  rouinuin  ano 
widely  difTu^ed  •[leeieH.  «o  that  they  niu-t  on^'in.illy 
have  had  Minie  adianUitfe  over  most  of  tiie  other  spee.eH 
of  the  Keiius.  I  heir  modihed  desrendanLs,  fourteen  in 
numiier  at  the  f"(Hirteen-tln>ii>andth  irenerntion,  will 
prohahly  have  inht-riled  some  nf  the  same  advanlayeh 
they  liavp  also  heen  niudihed  and  iiiij>ro\ed  in  h 
diversified  manner  at  each  sta^e  of  deseent,  so  a.**  t<i 
have  heconie  adapted  to  many  related  places  in  the 
natural  eeon<imy  of  their  enuntry.  It  seems,  then-lorej 
to  me  extremely  pru!'  I)le  that  tliey  will  have  taken 
tlie  plare:^  of,  and  tl.  .-.  exterminati  d,  not  only  their 
parents  (A)  and  (I;,  l>ut  likewise  some  of  the  oriirinal 
species  wliieh  were  most  nearly  related  to  their  parents. 
Hence  very  few  of  the  oritrinal  spf<ies  will  have  trans- 
mitted oifsprintr  to  the  fourteen-thous.*indth  jrenera- 
tioii.  We  may  Sllppo^e  that  only  one  (F),  of  the  two 
spe<ies  which  were  le:4.st  clo.-.ely  related  to  the  other 
nine  oritrinal  species,  has  transmitted  deiscendantH  to 
thi.s  late  sfa;re  of  descent. 

The  new  .species  in  our  diaa^ram  descended  from  the 
oritrmal  eleven  species,  will  now  1h*  titleen  ni  uijmli«r. 
()winji-  to  the  divergent  tendency  of  natural  selection, 
the  extreme  amount  of  difference  in  character  U*tween 
species  a'*  and  :'*  will  l)e  much  arreater  than  that 
between  the  most  different  of  the  orijrinal  eleven 
spei'ies.  The  new  species,  moreover,  will  l>e  allied 
to  each  other  in  a  widely  different  maimer.  Of  the 
eijfht  descendants  from  (A)  the  three  mart\ed  a'*,  7'*, 
p'*,  will  he  nearly  related  from  haviii;:  recenfJy 
branched  off  from  ij''";  '/'*  and/"'*,  from  havinir  (ijvf  ri:e«i 
at  an  e;irlier  |>erind  frum  a^,  will  !>e  in  .some  de^-^ree  di»- 
titn"t  from  tlie  three  first-named  species  ;  and  la.stly, 
0'*,  f '*,  and  m '♦,  will  \>e  nearly  related  one  to  tiie  other, 
but  from  havinj.'  diverged  at  the  hrst  c«»rnmefHemetit  of 
the  prtH-ess  of  modification,  will  he  wideiy  different  from 
the  other  five  species,  and  may  constitute  a  Buh  jfeuus 
ur  even  a  di.stiuct  i^euug. 


112 


ON     I  UK   ORIGIN   OK   HI»E(  lES 


The  six  deart'iidaiitp  from  (Ii  will  form  two  sulv 
jfeiicra  or  even  ^enor.i.  Hut  ;ijj  the  ori<rin:il  H|K»cie8  (I) 
ditltTi'fl  lariTf'lv  fnitn  (A),  -^taiKlini,'  ne^irly  at  the 
extreme  p  »iiitfi  of  the  oriiriiial  jfeiiuh,  the  six  (it^- 
s<!eiidants  frt)m  (I)  will,  owin^  to  iiiheritan.e  alone, 
dirter  considerahl"  from  the  eight  (iefcendanU  rroin 
(A)  ;  the  two  er<iuj»s,  moreover,  are  HUppo^ed  to  have 
j^one  on  diveririiiff  in  ditierent  direetious.  Hie  inter- 
mediate sprcies,  also  (and  this  is  a  very  important 
consideration),  whi<li  connected  the  (tntrinal  spocieti 
(A)  and  (1),  have  all  l>ecome,  exceptintr  (F),  extinct, 
an<l  iiave  left  n(t  (lt'sc»'iid;int.s.  Hence  the  six  nev 
species  descended  from  (1),  and  the  eitfht  den-ended 
from  (A),  will  have  to  be  ranked  as  very  distinct  >:enera, 
or  v\k'\i  a8  distinct  «ul>-faniilies. 

I'huH  it  is,  as  I  helieve,  that  two  or  more  irenera 
are  produced  by  descent  with  modification,  from  two 
or  more  species  of  the  same  jjenus.  And  the  two  or 
more  parent  species  are  supposed  to  have  descended 
from  some  one  species  of  an  ••arlier  treiius.  In  our 
diagram,  this  is  indicated  by  the  broken  lines,  l»eneath 
the  capital  letters,  converjrinK  in  sul>-branches  down- 
wards towards  a  sintrle  |M)int  ;  this  point  representiu^r  i 
rtinf^io  species,  the  supposed  sii^fle  parent  of  our  several 
new  sub-^-^enera  and  trenera. 

It  is  worth  while  to  reflect  for  a  moment  on  the 
character  of  the  new  species  y  '*,  which  is  supimsed  not 
to  have  diverj^e^l  much  in  character,  li:it  to  have 
retained  the  form  of  (F),  either  unaltered  or  altered 
oiilv  in  a  slitrht  deuree.  In  this  ca-e,  its  atHnitie^  to 
the  other  fourt»'en  now  specie-s  will  be  of  a  curiou-  and 
circuitous  nature.  Havintr  descended  from  a  form 
wiiicli  stood  between  the  two  parent -s[tecies  (A)  and 
(1).  now  supjM)sed  to  he  extinct  and  uni^nown,  it  will  ttf 
in  some  diirree  intermediate  in  character  between  the 
tHC  irroups  descended  from  these  specu-s.     Hut  as  these 

&'•••( ?, -■--—.     —  .'.  .11 

the  ty})e  of  tbeir  parents,  the  new  smvies  (k'*i  vvill 
not  lie  directlv  intermediate  between  them,  but  rather 
i)et«epu  types  of  tbe  two  irroups  ;  and  every  naturalist 


NATURAL   SELECnoN 


ll;3 


••viil  Ik?  al)!e  to  i)rint:  .'•orne  such  r;is«  Iwrore  iii- 
miini. 

Ill  'hf  iliatrr.iin,  «>.»(  h  lion/ontAl  line  harf  hilliPrto 
I  I'f'ii  ^uppo-fii  til  rt'prestMit  a  tiidii-am!  trt«norati'>;H,  luit 
♦•aril  m.iv  ;t'pri.>t'i.t  a  inilliuri  or  iii;i,.lrcil  iiiillion 
trt'iieratioii'^,  iiul  Iik»-\M-t»  a  sortion  oi  the  successive 
•strata  of  the  cir'.li's  crust  iiiclinliiiir  extinct  reniauiH. 
\\  »•  r*}iall,  v*  iicn  wt«  couio  to  our  diaptcr  on  (ieolo^^y, 
liave  to  rcr-T  a;.'-ain  to  tlii-;  sul'jet't,  and  I  think  wc  rhall 
then  sec  tliat  the  dia;;rani  throws  lij'-Jit  oii  the  nfHiiitics 
at  exlujct  hciniT-,  which,  tluunzh  jrciierally  l)ch)i:;:iiiir 
to  "'ic  same  ordt'i?.,  ur  families,  or  t^'cnera,  with  tiiose 
nou  iiviiii'',  yet  are  often,  in  -onie  (ie^Tee,  interntediate 
in  character  iietween  e.vi^tinj;  f^mups  ;  and  we  can 
undersUuid  this  fact,  hjr  the  extinct  species  iiveil  at 
very    au(  epochs    when    the    hrauchiug    lines    oi 

descent  1:  vcfirt'd  loss. 

I  see  nc  reason  to  limit  the  [irocesf  of  moditication, 
as  now  explained,  to  the  formation  of  genera  alone. 
If,  in  our  diairram,  we  siippo>e  the  amount  of  change 
represented  hy  each  suices>ive  trroup  of  divertjinj^ 
dotu'd  lines  to  he  very  trreat,  t!ie  forms  marked  a  '*  to 
/)  **,  those  marked  '< '*  and  /'■*,  and  tho.-.e  marked  o  "  to 
m  '*,  will  form  three  very  distin<t  t:enera.  We  sfiall 
also  liave  two  very  distinct  f^eiiera  descended  from  (I)  ; 
and  as  lliese  latter  two  t^enera,  both  from  continued 
diverL'cnco  of  tharacter  and  from  inheritance  from  a 
ditferent  parent,  vill  differ  widely  from  tlie  three 
tjenera  dtsceinled  from  (A),  the  two  little  trruups  of 
4fenera  will  form  two  distinct  families,  or  even  orders, 
aecordiiiiT  to  tlie  amount  of  divertrent  moditication 
snp!»o^ed  to  he  repre-eited  in  the  d;a_'ram.  And  the 
tvM)  new  faniilie<,  or  nnicrs,  will  liave  descended  from 
two  -pccies  of  t!ie  orit^inal  L'en-is  ;  and  thcvc  two  >pcciea 
are  suppo>ed  lo  h.i\e  <ie^cended  from  one  Hpecies  of  a 
still  more  ancient  and  uuknonn  ^'enus. 

We  liave  seen  that  in  each  country  it  is  the  '•iieriea 
of  the  laii^er  ;rencra  wliich  otlenest  present  wirietien  or 
incijiient  species.  This,  indeed,  nii^rht  have  been 
expected  ;    for  a*,  natural  selection  acts  through   one 


11 1 


ON    IIIK    OKKilN    OK   SI»E(  IKS 


form  linxiiiiT  fMiiie  aflv.iiiUito  over  otlior  form?  in  the 
stru;:::lf  lor  i'.\islt>iitu',  it  will  'liii'lly  act.  on  liio>-e  wliicli 
Jilmnly  li.ivc  ?.(iiiu'  aih  riiita;.'c ;  ;iii'l  tiie  I.irj^eiU'ss  ot  any 
(i^ruii)/  -.Ikiw^  tli.u  its  sjicfU's  1ih\»'  iDiicritcd  from  a 
coMUiioii  ;inr('vtiir  somo  .'I'lNaiit'ii,'!'  in  coinnion  llcncj', 
the  »'rii:rirl«'  tor  tli(»  ]>ro(iijction  of  nt'w  ami  nioditied 
iic-i<'iiiiiint>.  will  rnainly  he  hotwt'cn  tlii*  lar:ror  tfroiips, 
\\liii'li  Jirt'  all  tryi  '  to  incrt'aM;  in  nninlier.  One 
lar:i««  i^i-onp  will  slu  s  ly  cuniiiicr  another  iar^M^  trroup, 
ri'<ii.(f  it-  nurnlKT-^,  ami  tlius  If^-rn  it>  cliatirp  of 
lurtln'r  variation  ,in<i  im]irovenu'nt,  W'itliin  tlif  ■<irne 
lartrt'  irronp,  the  later  and  more  liitfhl\  pertf<"t4>d  sul>- 
jrroup^  from  liranchint:  out  and  sei/.ini:  on  inanv  new 
]piare>  in  tlie  polity  of  Nature,  \\ill  eon^tiintl^'  tt  tid  to 
Mi-'pinnt  anil  de-troy  the  earlier  and  less  improved 
sni>i:rnii!H.  Snia  ,  and  hroken  trroup^  and  suh-t^roups 
will  Ini.illy  di».i|..  ar.  Looking  to  the  tutiire,  we  can 
J  i<-dict  that  tl.r  :.Toiip>  ot'  orj.Miii  heintrx  wlmh  are 
n<iH  lart'e  and  '.iMiinphant,  and  wlucli  are  least  hrnkeri 
nji.  th;;t  is,  ^\h!,•h  as  yel  liave  -uliereii  lea-l  e.vtnntion, 
will  tor  a  liiii;.'  peri((<i  eimtiiii.e  to  increase.  I4ut  which 
^Tiiiips  w:il  uitiinately  jirevail.  no  man  can  j'ledict  ; 
t'nr  we  w.'li  know  tiiat  man\  ^Toups,  furitieriv  most 
e\teu>-i\  ei\'  de\elo[ied,  !,,i\e  no\^  Income  extinct. 
I^"*k;n'_'-  .still  more  remotely  to  th-  future,  we  may 
preili.  ;  thai,  owiiiir  to  the  contiiuied  and  steady  in- 
erea-e  of  the  lander  jrroiqis.  a  multitude  ot  smaller 
trruu[w  wii;  lieiome  utterly  extinit,  and  leave  no 
ino<i,!ied  dest-enilant^  ;  and  c'onseijuentU  that  ot  the 
s|iec!e>  livinir  at  any  one  |)eriod,  extremely  few  will 
♦  ran-iiiii  descendants  to  a  remote  futurity.  1  shall 
ha\e  to  re;  urn  to  this  Kuhject  in  the  c}iaj)ter  on 
(  i.is-iiKMtion,  hut  I  may  add  that  on  this  view  of 
I'xtremely  tew  of  the  more  ancient  spe»ies  havirijf 
transmitted  de-cend;int.s,  and  on  the  view  of  all  the 
ile^ceiidaiits  ot  the  siime  species  mahinti  a  rla>p;,  we  t-an 
understand  how  it  is  that  there  e\i>t  hut  \ery  few 
cia-^ses  HI  eacii  iiiiun  <inision  t»i  liie  aiiimai  and  \  ejf  »^ 
t^ilile  kin;.doms.  Allhouyh  extreiiud\  lew  of  the  mo-t 
aniicut    species    mav    imv*    haw    livinjr    and     modilie<l 


NATl'UAL  SKI-P:(TI()N 


116 


deHceiiHaiit>i,  yet  at  the  most  rt'tnoto  :r»>(»lot;ical  period, 
the  earth  may  have  Ixjen  ns  w '11  ]>«'«i|)leil  with  many 
"Ufcies  (if  many  trcnera,  farnilit's.  orders,  ami  rhui.ses, 
AS  at  the  present  'lay. 

ISumrtuiry  of  ^'Kiifitt'r.  ~~l{  dunns  the  lotitr  course  of 
lires  ami  under  varyiu(f  eornlitioriji  uf  lite,  organic 
h.-inys  \fiT\  at  all  in  the  several  {>artfl  ot  their  or^'aiiisa- 
tion,  anil  I  think  this  cjiunot  he  disputed  ;  ir"  there  he, 
Dwintr  t''  the  hitrh  t^eomctrieal  ratio  ot  imrea.He  of"  each 
specie-,  a  severe  striit^irle  for  lite  at  some  aire,  sea.-un, 
or  year,  and  this  certainly  cann«»l  Ik?  di-puled  ;  llien, 
consideriuif  the  intinite  complexity  of  tlio  relations  ol 
\U  organic  heinirs  to  each  other  and  to  their  conditions 
ol  existence,  causintr  an  infinite  diversit\-  uj  structure, 
constitution,  and  hahitjs,  to  he  advatitatreous  to  them, 
1  think  it  would  Ix*  a  tnost  exlraunliiiaiN  fa<-t  if  no 
variation  ever  had  m  curred  useful  to  each  heintr  .■*  own 
welfare,  in  the  satne  manner  as  so  manv  variations 
iuiN  e  occurred  useful  to  mati.  liut  if  \ariations  useful 
to  any  tirL'"atiic  beinir  do  occur,  assuredly  individualg 
thus  ctiaracterised  wiii  have  the  best  chance  of  Uunir 
preserve<l  in  the  struiTi^le  for  life  ;  and  fr(»m  the  stronjf 
iirin«uple  of  inheritiince  they  will  tetid  to  i>rr>duce 
titf-[irinff  similarly  clriracterised.  Tiiis  principle  of 
Iirf>ervati(ui,  1  have  •  ailed,  for  tlie  sake  of  Itrevitv, 
Natural  Sele<"tion;  and  it  Iwids  to  the  improvement  of 
each  creature  in  relation  to  its  orjranic  and  inorganic 
cotiditioiis  of  life. 

Natural  selection,  on  the  prificiple  of  i^ualitia"  heiiij? 
inhenlefl  at  correspond i lit:  aL'es,  can  nioility  tin'  eir^j, 
si-eil,  or  youn^,  as  easily  a--  the  adult.  Afiioiiirst  many 
anitnals,  sexual  selection  will  trive  its  aid  to  ordinary 
selection,  hy  assurini,'  to  the  most  vij^nirous  and  !>e.st 
adapted  maU'^  ihe  ^'reatest  numtn'r  of  ofisprinj.'.  Sexual 
sfiection  will  also  (jfive  characl*»rs  usctii  to  the  males 
alone,  in  their  sirueirles  with  other  males. 

W  lietiier  natural  -election  has  naily  thus  acted  in 
nature,  in  fiiodifyin^'  and  adaptintr  the  variouo  form« 
of  life  to  their  ^everal  conditions  and  st;itiou>,  must  bti 


!!•; 


ON    niK    OKKJIN'    OF    SI'Ki'II'S 


judcP'I  "t"  l>v  till'  tri'iieral  tenor  arnl  It.il.inrp  i.t  t-vidcme 
^riv»Mi  in  tin'  fMllowirij.'  ••hajitcrs.  IJut  we  .-ilroady  hp»« 
li<nv  it  f'TitailM  rxtiuction  ;  .iMii  Imw  l.irizt'lv  extinrtinu 
IwH  actriJ  in  tin'  norM'^  lii^turv.  .'roldtry  jii.iiniv  (]••- 
rlarc-i.  Natunil  >r'le.tioii,  ;tl-<i,  It-  i.ls  t<>  <iiveri:eiioe  of 
riiaracttT  ;  fur  inort*  livitiL'  l^'inir*  «"tii  f>o  swjijinrtrd  ou 
t*i»'  sainc  rirc.i  'lit  more  they  divorce  in  •itriii'*Lirf, 
haliit^,  ;ui<i  con-titution,  of  wh'ch  we  see  i-r<'<it'  *jv 
IfxikiM:;  td  tht'  iMhal)it.'int-s  of  any  small  spot  or  t'> 
na'  urali-eil  [irndurtioii-*.  i  lierefore  (iuriritr  the  nuMiirica- 
tion  ot  tlie  'Icsci'!!  Ian*.-*  ot  aii\  one  ^|)e<•le■<,  and  durin»: 
t.lie  incessrint  -t  riit{t^le  of  .all  8pe«-ies  to  increase  in 
!r:riiliers,  the  mi.re  diMTsified  the-ie  descendants 
iiecome.  the  Itetlcr  «ill  be  their  cluiiice  of  hih  ceedintr 
in  tlie  li.i'^'f  ♦or  life.  'I'liiis  the  small  ditforences 
distiiiL'^ui-'liini:  varieties  of  the  Karne  >i])ec!;'s.  ^teadiiv 
tend  to  incrca-e  till  they  come  to  eijiial  the  greater 
ditTereuces  Ketwceii  species  of  ihe  same  ^fentis,  or  ever' 
of  dir-tinct  trenera. 

N\'e  liave  seen  that  it  is  tlie  common ,  the  widely- 
ditfused,  and  widely-rantrintr  spe<'ies,  Ixdonifiiiir  to  the 
lartrer  {fen»'ra,  which  varv  most  :  and  these  tend  to 
'ransTiiit  to  their  modified  ofTsprintr  that  nupenority 
whu'h  now  makes  them  dominant  in  their  own  coim- 
trie'*.  Natural  selection,  as  has  just  heen  remarl<ed. 
kvids  to  divertrenco  of  character  and  to  much  extinction 
of  the  less  improvetl  and  iiitennediate  forms  of  life. 
<  hi  these  principles,  1  believe,  the  nature  of  the 
■ilRnitic  of  ail  or^'amc  bein;:s  may  be  explained.  It  i> 
a  truly  wonderful  fact — the  wonder  of  which  wo  are 
ant  to  overlook  from  familiarity — that  all  animal.s  ami 
all  plants  *broii::hiHit  all  time  and  space  siiould  1m' 
related  "o  e^ich  other  in  fZT""P  subordinate  to  jfroup,  in 
rhe  inai.ner  which  we  everywhere  behold  —  iiamelv 
>aiietie-i  of  the  sinie  species  most  closely  reiated 
O'.'etlier.  species  of  the  same  ^enun  less  closely  aufi 
'inei.Mialh  related  toirether.  forininir  sections  and  sub 
j-enera,  snccies  of  distinct  genera  miicli  leaw  closely 
related,  and  tretiera  relattvl  in  ditTerent  de^ree^. 
forming''  -ul>-fniiiilies,  faniilios.  orders.   sul>-clai«e«»,  and 


NAT!  RAL   SEl.K(Tr«n' 


117 


olas8A»s.  Die  spvtT.iI  <iil)nrditi<'ito  yrmiji-  in  any  cIomh 
'iinnot  he  rankt-d  in  ;i  sintflt'  til»«,  l)Ut  -♦H-tii  ratlifr  to  lie 
t  lii>tere(l  roiinil  jtoiiil^,  and  tl)t'>e  ruund  ottuT  jxtiiiLs, 
and  «o  nil  in  almost  eiidlesM  cycles.  (  »n  tlu»  vi(<w  that 
'-.tell  sjKjcie?  h:is  \n'vu  iiidejHMidcntly  iTfatni,  I  can  so»> 
;;o  explanatinn  of  this  jfreat  fact  in  tlie  chi-ssi;ication  of 
ill  organic  iK'intrB  ;  hut,  to  tlie  hest  of  my  .iud;rment,  it 
H  exjdained  throuirh  iiihoritarce  and  the  complex 
ictioii  of  natural  nolection,  eiiUtilinjf  extinction  an<i 
'livertjence  of  character,  as  we  have  seen  illustrated  in 
'lie  dia^'rani. 

I'he  atlinilies  of  all  tlie  l>einf:s  of  the  same  clans  have 
■sometimes  }>een  represented  hy  a  ^reat  tree.  I  helie\e 
thi:^  wimile  lar^'ely  speak-  tlie  truth.  I'he  ifreen  and 
'nnidin^  twijrs  may  renresent  existing  sjiecies  ;  and  those 
jircxluced  durinp  cich  former  year  may  represent  the 
iontr  succession  of  extinct  epe^'ies.  At  each  peri(Ml  of 
LroHtli  all  the  prowinif  twiffv  liave  tried  to  hraiicli  out 
on  all  sides,  ami  to  overtop  and  kill  the  surroumlirnr 
twijr^  and  [(ranches,  in  the  ^amp  manner  as  H[>fcies  and 
eroups  of  species  hare  tried  to  f)veriru4.sler  other  species 
in  the  jrnvit  hattle  for  life.  Hie  limbs  divided  into 
trreat  branches,  ami  these  into  lesser  and  lesser  brnnrhes, 
«ere  themselves  once,  when  tlie  tree  wa.s  small,  huddinir 
twitrs  ;  and  this  connection  of  the  former  and  pre.sent 
tiiids  hy  ramifyinjf  hranches  may  well  represent  the 
cla^isitication  of  all  extinct  and  livinj;  specie-  iu  trroups 
suliordinate  to  croups.  Of  the  many  twijrs  which  riou- 
ri^hed  when  tiie  tree  was  a  mere  nush,  ouly  tw(»  or 
three,  now  g'rown  into  irreat  hranches,  yet  iiurvi\e  and 
bear  all  the  other  hrancli«^-<  ;  so  with  the  species  whicli 
iive<i  during  long-past  ideological  periods,  \  ery  few  now 
bave  living  and  modified  descendants,  h  rom  the  firs; 
:^owth  of  the  tree,  many  a  limb  and  brancii  havedecavt>»! 
ind  dropped  otf ;  and  these  l(»st  hranciies  of  Narioun 
sizea  may  represent  those  whole  order>.  families,  ami 
genera  which  have  now  no  living  representatives,  ami 
which  are  known  to  us  only  from  having  been  found  iu 
a  fossil  state.  As  we  here  and  there  see  a  thin  stratr- 
t'ling  branch  sprintrin?  from  a  fork  low  down  in  a  tree, 


iin 


ON    TJIK    OHI(;iN    OF   SF»K(  IKS 


and  wliich  hy  «i<>nm  chance  ha-i  lieoii  favoured  and  is 
■till  alivo  on  itn  summit,  ho  wf^  occasionally  see  an 
animal  lil<t»  t!n'  <  >riiith(irliyiichas  or  I/«'|)idosir»'ri,  which 
in  hoiiM'  Kniail  (Ic^-^rco  cnnricctj^  by  its  affinitit"*  two  larcfl 
branches  of  life,  and  wliirh  has  ai>panMitly  f»c>cn  savtMl 
from  fatal  competition  hy  havint;  inhabited  a  protr<t»»d 
station.  As  t)UiiH  jjivo  rs^o  hv  trrowth  to  fresh  huds,  and 
these,  if  viL'^firoiis,  branch  out  and  (nertop  on  all  Hide** 
mariv  a  fct-Mer  hranch,  so  hy  feneration  I  helieve  it 
h;u4  hepii  with  the  t,'^roat  free  of  Life,  which  tills  with 
its  dead  and  hroken  branches  the  crust  of  the  earth, 
and  c(>\erK  the  surface  witli  ibt  ever  branchinjf  and 
^)eauti^ui  ramification'*. 


CH  APT  Ell    V 


UlWg    <>K    VAUIATIOW 


Bflf' t»  "f  extpnikl  ,ni,.litlf.nf  t'w  aU'i  luu**,  combliicl  wllh 
iri'iiril  ».l.-.  ti..n  ;  .  r^-ans  "f  ll.-ht  aii'I  f  vuL.ii  -  Ai(.ltiiMli»»^ 
tl.ii-  ('."rrflnti- n  at  Kr^wili  <  •■rTij^nimti'n  ami  fo..ri"niv  <>t 
ur-iwth-  Kalie  r.irTfUlt>>ii»--MuUii.l<-  ru'liiiitft.tary.  hikI  I  wly 
,.rK.iijUr-l  »tr;  tur-*  ^  irl.il'le-  I'ntU  .levt  I  .jmM  in  an  \ii  n>.al 
nia-i'UT  nr.-  lil«lily  varlaMf:  Hf-iifl.-  (  hitrsit.  r»  ni.ire  vnnuile 
than  Ketitrlc  :  Kvinliir)  boiuhI  characteni  vanaMf  ->i...ii»  of 
thf  '.iiif  tf'iiin  viiry  HI  an  iit,al"»;vu»  tiLiiiucr  ltovfr=i  ii»  to 
I'Mit;  I'.st  1  liaract«T«    Suiuin  iry. 

I  HA\  K  hitherto  sometitnps  spoken  08  if  tlio  vanatioiig 
— RO  ciimmMU  and  multiform  in  ortranic  U-iiiirs  under 
.Jomofitiration,  and  in  a  looser  dei.Tee  in  tliose  in  a  state 
(»f  nature  -  had  l^'cn  due  to  chainH.  Hus,  of  course,  is 
.1  wholly  incorrect  expression,  fuit  it  servet*  to  acknow- 
ledire  plainly  our  iifiiorance  of  the  cause  of  each  par- 
ticular variation.  Some  authors  l>elie\  o  it  to  he  as  much 
the  function  of  the  reproductive  syntem  to  pro<iu.e 
individual  ililterences,  or  very  slu,'ht  deviations  of 
dtructure,  as  to  make  the  child  like  ita  |)arent^.  I5ut 
the  much  greater  variahility,  as  well  as  the  >:reater 
fro<|ueucy  of  monstrosities,  under  domestication  nr 
cultivation,  than  under  nature,  leads  me  to  heliove 
that  deviations  of  structure  are  in  some  way  duo  to  llie 
nature  of  the  cnnditi(»ns  of  life,  to  whi-  li  the  parcntM 
and  their  more  remote  ancestors  have  been  exposed 
.iuritu:  several  ;:enerations.  1  have  remarked  ni  'he 
rirst  ciiapter — i»ut  a  inni;  <  .tliiii'iiUt-  or  rr.rts;  -.vrijcn  ;.■;;:::;;» 
he  here  yiven  would  !ie  necessary  to  show  the  truth  of 
tlie  remark  -  tliat  the  repnHiucuve  sv,,teiii  is  eminently 

ll:t 


120 


ON  T;n:  oiucjin  <>f    ri:(  iks 


Bu-M-i'iitilih'  to  cliaiices  in  tlio  comlitioriH  of  lift-  ;  and  to 
tlii-«  •'y-t»'rii  Itoititr  functinri.illy  (li^tlJrl•<•ll  in  t}ii»  jirirent*, 
I  rliivlly  .tltriLiiti'  fill"  \.iryiiii:  nr  pl.i-tif  <M»ri(lit.(iii  of 
t)i'-  oirspriii;:.  riic  iri:iU>  arnl  fiTii.iIr  wxii.il  ricment"! 
sfiMii  to  l.(«  affpctod  ln'f"nn'  that  lin.iin  taki'-  plac*-  wJiidi 
is  ♦'•  f><ru\  a  now  Immiic.  In  tlic  .a-c  «»f  '  s|Mirtiiii: ' 
{ilants,  tlio  l)nil,  wlii.-li  in  iti  t»arlio<t  rondition  (lui--  not 
ai«|)aroiitl\  .|it!iT  ••^^cntially  froin  .in  n\iilp,  i*^  alorif 
a!!fi-ti'ii  I'.ut  wliy,  Ix'.'aijsi'  flif  rf|iri>()intive  ny^tcni  i» 
(ii-tiir!if'(i,  till"  or  that  part  "IhiuM  \ary  more  or  If.v,  we 
art'  profoiUKily  iiriiorant.  N('\  prth»•l^'«i^,  wo  CHii  lior«' 
.iM(i  llifn>  (liirily  raN-h  a  faint  ray  ol  litrht,  ami  we 
may  feel  Kiirc  that  there  must  he  some  caiiw  for  each 
(icviatioii  of  Ktrnctiin',  lioweviT  slij/ht 

Flow  nnicfi  (lirfct  etTf.t  diMcrerne  of  climate,  food, 
etc  .  jiroducrJ  on  any  heinj^^  is  cxtremelv  dctnhthjl.  My 
■niprc— ion  is,  that  the  effect  is  extremely  small  in  tlie 
I  aM'  <if  animals,  hut  iierliaps  ratlior  more  in  that  of 
plants.  Wo  may,  at  lea-t,  safely  conclude  that  such 
indnenres  cannot  liave  [irodtued  the  manv  strkint: 
an»J  complex  co-adaptations  ot  structure  hptvrecn  one 
oriranic  hein:.''  nnd  another,  wliirli  we  >ce  e\cr\  ■•(  lu-re 
throinrliout  nature.  Some  little  indueinte  mav  i^o  attri- 
buted to  climate,  food,  etc.:  thus,  K.  ForUis  speaks 
■•oiitidently  that  shells  at  tlieir  southern  limit,  and  wlien 
livinu  in  sliallow  water,  are  more  hrii^litlv  coh»ured  than 
^  species  fu 
helie\es  th 
.ire  more  'iritrhliy  c<)loure<l  under  a  clear  atmo-^phi-re, 
ttian  when  livintr  on  islands  or  near  the  coa.st.  So  with 
insei'ts,  \\'(dlaston  is  convinced  that  residence  near  the 
sea  affects  tlieir  colours.  .Mixjuin- Tandon  trives  a  ligt 
ol  plants  whicJi  when  irrowititr  near  the  sea-shore  have 
(heir  leaves  in  some  deirree  fleshy,  though  not  eNewliere 
tleshy.     Several  other  such  cases  could  he  y^iven. 

riie  fact  of  varieties  of  one  species,  when  they  raiitifl 
into  the  zone  of  liahitation  of  other  siiecics,  often 
fii  tjiiir;-::;;  Sii  tt  Very  >;|;irht  ue^rrce  -iomo  in  tiif-  charariefs 
vt  auch  nperies,  accords  with  our  view  tha*  species  of 
al!  ktuds  ,»re  only  well-markci  and  pernia!!e:it  vane'ien. 


those  of  the  same  snecies  further  north  or  from  ifraner 
depths,      (Jojild   helie\es  that  hirds  of  tlie  same  s|K-tie8 


Iw^ 


lE'^cS^ 


LAWS   OF   VAIUATION 


121 


TTiuH  the  gporic-  of  nholln  wliii  h  are  ((iiitiued  to  troj>'..al 
aud  ulialln*  hvha  :irc  tft-iu-rnllv  br>Klitrr  roloure.l  in 
fhoHO  iftiifineil  to  ^•^>\^\  .iiid  liwper  hww.  The  l..ril« 
whii'i  are  ronfiiutl  to  coiititM'Tit-<  arc,  aconliriu'  to  Mr. 
irt)u!(l,  hriirlitor-<'oloured  llian  thi>«»»  of  i>laij<lx  I  lio 
•  nx«>rt-sj>ecK'>^  i-<»nfiiir<l  to  «t>a-(  oantu,  a-  i-very  »-olU'<  tor 
knows,  are  otteii  hransy  or  i.riil.  I'lantj4  whii-h  live 
♦•xilimivolv  on  the  sca-'«i<le  an-  v^ry  H|>t  '<•  liav(<  tli'-h? 
leaves.  lie  i<  tio  believes  in  the  i  reatinri  ot  earh 
^jMM  ie«,  will  ha\e  t<'  ^^ay  that  this  sliell,  for  iiislaine. 
wa-  create«l  with  l>rii.'ht  colours  for  a  warm  •«'  i  , 
hut  that  this  other  shell  heeanie  liri^'ht-coloured  hy 
variation  when  it  rauKe*'  >'>to  warnier  or  shallower 
waters. 

N\  heu  a  variation  is  of  the  sliirhtest  u*e  to  a  lieititf, 
we  eanrsot  tell  how  mueh  of  it  to  attribute  to  the  a«»;u- 
rmilativp  action  of  natural  Mjh'ctiDii,  and  how  much  to 
the  conditions  of  life.  'I'hu",  it  is  well  known  to  fur- 
riers that  animals  of  the  sijine  s|)e<  ie'^  have  thicker  and 
better  fur  the  more  severe  the  climate  is  under  wiiicii 
tlitu'  have  lived  ;  hut  who  can  tell  how  much  of  tin* 
ditferente  may  he  due  lo  the  warmest-clad  individual-t 
havingr  been  favoured  and  preserved  durintr  nany 
:;e:.erit'ons.  and  how  much  to  the  direct  action  of 
the  severe  climate.'  for  it  won!!  app'-ir  that  clirr.ate 
lirvs  Bome  direct  action  ou  the  hair  of  our  doiru;.-it:i" 
qua«iru|)e<l«. 

Instances  could  be  iriven  of  the  s-ame  variety  beiiu' 
pr«»<iuced  under  conditions  of  life  as  different  as  can 
well  1)6  conceive<l ;  and,  on  the  other  hand,  of  ditferent 
varieties  1km n^r  pro«Iuced  from  the  same  sj»e«'es  under 
ihe  same  conditions.  Such  fact>  show  how  iiidiro<-tl. 
the  conditions  of  life  act  Again,  innumerable  instances 
are  known  to  every  naturalist  of  sj>ecic8  keepintr  true, 
or  not  varying  at  all,  althouirh  livinjr  under  the  mopt 
opposite  climates.  Such  considerations  as  these  incline 
me  to  lay  very  little  weight  on  the  direct  action  of  the 
•ondilions  of  life.  iu<iireciiy,  as  aireadv  ieiiia?Ke«i, 
the"  seem  to  plav  an  imjuirtiinl  [lart  in  atfectnitr  the 
re;'ruductive  aysteni,  and  in  thus  induiing  variability  ; 


122 


')S   THK    ORKJIV   OF   SPKCIKS 


.4'!ii  ri.i'iirrt!  -flection  will  tlion  •irciirrmiatc  all  [)r<ifitAi>le 
vrinat  c>ii>.  ".v.vt'r  "-li^'ht.  until  they  IxH-omo  plaiiilv 
(ievcloj  f(l  iiM  I  apfiriM'iaMt;  \>y  'n*. 

tlif^'ts  fif  I'y  mid  lhx\iiif. —  i''rnni  'lie  fn.r\^  alliiiicd  tn 
ifj   the  tirst  ciiafifcr.  I    think   thfre  can   Ik'   litt  lo  lioiih! 
that  use  in   ntir  fionMwtic  aniinai-;  ^t  rpntrtli«iis  an-l   vw 
lartres  certaiii   ii.irt.>J,  ami  'lisu-^c  dinii'ii^lit's  thorn  ;  ani 
that    suctt    mo«lificati<in.-i    aro    iiiln'ri'i'ii.       I'mitT    trt'o 

■  'nre,   wo  can    have   no  htaiulard   vl   ''uiiiii,ir-"n.   hy 
I  .'  h  to  jmlirt*  i)f'  the  etTects  nl'  'onij-roiitiniu'ii  use  i-r 

di'...;  e,  tor  vve  ktiuw  not  the  pamnt  fe-rii-:  ;  hut  many 
.».  •m'!.!  have  structure-;  which  can  '•••  explainei!  }>y  the 

■  'ects  ot  i!:«.nse.  A-<  Prnfes'-or'  '.vcis  h;!>  re'iLirki-d,  t.liere 
in  no  ert^ater  anomaly  in  Tiature  than  a  hird  tliat  cannot 
fly  ;  yet  there  are  several  in  tins  sta'e.  I  he  loiTL'tT- 
hendeil  duck  of  South  America  can  only  flap  alontr  ;he 
BurfVtce  ot"  the  wati-r.  anil  iias  it-;  \viii^--<  in  nearly  the 
same  coniiilKii  a-  the  donu'situ:  Avle-hury  duck.  A^.  tlie 
lar^rer  irrounii-fetMiuiL'  hirds  hi-Mcui  t;ike  r'.i^ht  except  t<^i 
es<-af  e  d:Mi:,'er,  I  nehevo  that  the  ni'arly  winL'le>s  condi- 
tion 'It'  Ke\er-ii  hirds.  hIui  h  'ow  inliahit  or  lia%'e  late!;, 
inliai'ited  -e\eril  oce.anic  i-^land-i.  tenanted  hv  no  h  -a-. 
ot"  pri'\',  lias  (■een  caused  hy  di-^u.-e.  Tlie  o-tncli  indeeu 
iuhahits  continents  and  is  exposed  to  da'ii.'-er  from  which 
it  cannot  escape  hv  fliirbl,  hut  hv  kicking'  it  can  (leiend 
itself"  Horn  en«'mies,  ax  well  as  any  ot"  the  >tnailer  ijuad- 
rujH'tls  We  r'ia\-  iniaj-uu'  that  the  early  protrenitor 
of  ttie  ostrii'h  luid  liabits  like  tho--e  of  a  hustard,  and 
that  as  iiatural  selectioi;  iiicroased  in  jjuccessive  trenera- 
tions  the  si/»>  and  weiyht  of  its  hodv,  its  le^'s  were  u»ed 
more,  aiid  its  wiiej-s  less,  until  t!i«'y  liecame  incapahle 
of  liiirht. 

Kirhv  has  remarked  (and  I  ha'  e  ohserved  the  same 
^act)  that  t.'io  anter'or  tarsi,  ot  feet,  of'  many  male 
duTiiT- feeding  bt^etles  are  very  ot\eii  broken  utf;  he 
exarnined  sevetiteen  specimens  m  his  nwn  cidlertion, 
%;.<:     ;;iii    .r;f    ii  ir;    eve:;    r»    rv\.v    ;e:;..         ;:;     :   :;•    \  •-.iwir^ 

fcpelles  the  Uirsi  nre  so  hahitu-llv  lost,  that  Mie  insect 
h.iS    hi  en    desiuilied    e.s    fml    haviHiC    th-'ru.       In    swme 


AU'S    OF   VARIATION 


123 


othor  ?ei.era  tlu-y  .ire  present,  tint  ".\  a  rti<iimotitary 
LOMtlition.  Ill  tlip  Att'iu-iiiM  or  aacrtnl  ln'otle  of  the 
Ku'Vptian-j,  tln'V  aio  totally  <h-!'u-ient.  itiore  is  not 
suificuMil  *•'.  iiit'iiCt!  to  iniluce  nie  tn  Ix'lieve  that  miitila- 
tiOMH  art)  OMT  iiiiicrit»'(i  ;  and  I  -liu'ild  pnMrr  pxpiain 
uiji  'Jip  t'fitiry  ali-enco  of  iho  anter Or  l:ir-'i  in  Atcuchus, 
arid  their  nulinu-isUiry  cdiniition  in  some  other  irfiu'ra, 
bv  the  lonir-cont:iiiie«i  eiit-cts  of  ilisuxo  m  thoir  pro- 
t'pnitora  ;  tnr  as  the  tarsi  aro  almost  always  lost  in 
rnanv  iii;tii_'"-f*M"ii:itr  lK'»'tlps.  tliey  uri-t  li<>  1  )-it  early  in 
liff.  and  thereloro  fatinui  i»e  much  n<M  !>y  liiese 
ins«"t^. 

In  suiiie  rases  w-e   uu^'ht  cn'^Ily  put  dnwn   to  disuse 

riin.liiications  of  structure  which  are  '.vhnily,  or  mainly, 

due  tn  natural  M'lei  tiou.     Mr.  \\'olI.i-:ton  h.is  di-cosered 

the   remarkahle  fact   that   -J'hi   h.-.th's.  on.   of  the  .'>M 

■species    ;!ih;i*-itinir     Ma>li'ira.    are    so    far    dfficu'iit    in 

wii';L'S  that  they  cannot   fly  ;    and   that  of  the  twftity- 

nine  endemic  {,'erier.i,  no  less  than  twenty-lhr'H-  ir'-nera 

have  all  their  -iperjc-  in  tliis  conditio,!  '.     Se\eral   lacts, 

namelv,   thil   heothvs   in  many   f.arts  of  liie  world  are 

fre-juently   idonn  to  sea  and   perish  ;   thai  the  beetles 

iu   Maleini,  av  oi'-erved  hy   Mr.   W'olliston,  lie  much 

coie-ealed,    until    the  wnid    lulirt  and    tlie  sun  shines; 

that   tlie   proportion    ot    winj,^lesH   heet!e«i    :s    lar-'er  on 

the    exposed    l>eserta.s    than    in    Maiieira    iu^elf ;     and 

eH|KH'ialiv   the  extraordinary   fact,  to  strontriy  insisted 

on  tiy  Mr.   W  ollaston,  of  the  almost  entire  atisence  of 

certain    lari."  trroiips  of  U'-'tles,  elscwliere  excessively 

tiiimerous,  ;tnd  vstuch  groups  liave  hahiUs  of  lite  almoat 

neeessitatiiitr  fre«iuent  I'uu'ht;  -these  several  considera- 

'.ions  have  made  me  heln  ve  that  the  wuJtrless  coiidition 

of  so  many  .Madeira  beetles  is  manily  liue  ro  tli*'  action 

if  !iatural   st>iecnon,  but  combined    proba'iiy  with   dis- 

ise.      t  or  durinjr   tiiou-.mds  of  sucie.->si\e  generations 

-ach  ii:.ii\idual  iieetlo  which  i:ew  least,  either  from  ita 

ha\!n;r    iKfen    ever   so    littU-    le.sH    jM»rfectly   de- 


A-in^ 


>  t'il  'i'^'O      »  »l       i  J   Kill      I  !  Hl>   '     •-    HL     If*  .'*  ty       "^   I4»        ■  'tl •'*        ...*-        "^-     * 

■'hame  ot   survivin.:  frimi  not   bfiin;  bhwii  out  to  ^ea  ; 
an.i.    on    the    other    "ti.ind,    those    '.K-eUes    wh,ch    luoui 


■li 


124 


ON     IlfK    ORK.IN    (li     SPKCIK^ 


r».i<li!y  toitk  to  fli^iit  would  (ifUMic.-t  liavc  iifoii  hlo\rn 
to   -o.'i  and  thus  hnvc  liopii  <!^'str()ve<l. 

I  }i»*  itisoct-j  in  Madeira  whi<  h  .-ire  not  i.Tir..ii>i-ft'edor8, 
.trxi  vvliirli.  a"  Hjp  fiower-tVcliii:.'-  coh'oj.trra  a:id  Ippi- 
dotitcr.i,  rnust  Ji.iliit'ially  ii^f  !hp;r  wiiiif';  to  eraiti  'heir 
fluii-iftenc*',  have,  as  Sir.  Wjillasfon  •<uj-i>«H-t-.  'lifir 
wiriiT''  H'lt  at  all  rodurt'd,  liut  oven  onlartred.  Hii-  :n 
ijiiit-'  t'(ii!i].atil)lp  witli  tlif  action  of  natural  -.ploctinn. 
For  whiM)  a  now  in^.'ct  tirKt.  arrived  on  tl.c  :-..ini;.  the 
t.jmierii  V  ot  natural  "^(dectiou  to  Piilartrc  or  !o  r«'diii-e 
th»'  wu',:.*--:,  uould  dcjiciid  oil  w  lift hrr  a  trrpater  mimher 
of  indiid.iah  wo-c  s.ivt'ii  by  nuccessfulK  hnttlin;.'^  with 
tlio  winds,  or  by  invinir  up  tho  attempt  and  rartdv  or 
iievtT  living;.  A-*  witli  mar;npr«  shipwrockfr!  near  a 
coast,  it  would  liivp  l)eon  hcttfr  for  tin*  ^'■ood  f.v  ;Tiini<-rs 
if  th;'v  li.'id  hpon  ahin  to  ^".vinl  still  hirtlit'r,  wlitTca-  it 
wo, .Id  liavp  IxMMi  Ix'ttor  for  the  had  swirumo.--  :f  tlu'V 
had  not  been  ablo  to  swim  at  all  and  Lad  stuck  to  the 
wreck. 

I'he  cyef^  of  moles  and  of  somo  burrowinL'  rodents 
are  rudimontary  in  ni^e,  and  in  some  cases  -.re  cjuite 
covered  up  by  skin  and  fur.  This  state  of  the  eyps  in 
p.-oliahly  due  to  trradual  reduction  from  iisuse,  but 
aided  perh.ips  by  natural  selection.  In  South  America, 
a  luirrowiriiT  rodeiit,  tho  tuco-tuco,  or  (  U'nomvs.  is 
even  more  subterranean  in  iti-  haliits  than  the  mole  ; 
and  I  was  assured  by  a  Spaniard,  who  had  often  c.iuet.t 
them,  that  they  were  freijuently  blind  ;  one  wh:<  h  I 
Kept  ai;\r-  was  certainly  in  this  t-oiuiition,  the  cause, 
as  ap|ieared  on  dissection,  liaving:  been  intiammation  of 
the  inctitatintr  membrane.  As  fro.juent  intbmmatiou 
of  tlie  eye.s  mu.st  he  injurious  to  any  animal,  and  a*, 
eyes  are  certainly  not  indispensable  to  animal.H  with 
^l.htermneAn  habitjj,  a  reduction  in  tlieir  size  witli 
the  adhei»ion  of  the  eye-lids  and  trrowth  of  fur  over 
them,  miirht  in  such  ra-se  be  an  advantage  ;  and  if  so, 
natural  seJection  would  con.<itaiitly  aid  the  etfectn  of 
(iinuso. 

It  is  well  known  tiiat  several  animals,  belonerintf  to 
the  most  different  dasse",  which  inhabit  the  cave**  of 


L.WVS    OF    VAKlAlloN 


125 


Styria  .ind  of  Kfiitiirky,  an-  '  ,'1.  In  fomr  of  the 
c.TAhn  the  foot- stalk  for  the  »>yp  r.-nviiiKs,  thouijh  the 
♦•ye  i"  tT'Hie  ;  the  stiiid  for  the  te!e><*<)pe  is  there, 
tiioiiirh  thf  t»'le,<i'ope  with  i*-  j-iitsses  li;i.>«  Wen  h)>Jt. 
A-:  it  !■»  (liMiiult  to  ini.-itriTie  tint  eyes,  thoiiirli  u^ele^', 
rould  he  iii  .inv  \\;iy  iniurioii!*  to  .'iinmals  liv-ncr  in 
darkiies.-s,  I  .itiribiite  their  lo.«  wholly  to  livuse.  lu 
o!ie  of  the  Mind  anim.ils,  li.imeiy,  tin-  cave-rat.  the 
evos  are  of  immense  ^i/.e  :  and  Profes->or  >illin>an 
thoiia^lit  that  it  retrained,  after  livintr  ><onu'  d.iv-  in 
the  liirlit,  some  'sii:,'ht  jiowcr  of  vision.  hi  ;he  ■-aine 
iiiHiincr  .xs  in  Madeira  the  uuiirs  of  some  of  the  in*.e<t.«. 
have  h«x*n  enlart'ed,  and  tlie  wintrs  of  other-  !ia\e  iuen 
re<liiced  hv  natural  selection  aided  hy  use  and  di>  i^e. 
so  in  the  case  of  the  cave- rat  natiira!  st'h-.  tioii  seems  to 
have  3truci:lod  with  the  loss  of  iiirht  and  to  liave  in- 
creased the  size  of  the  eyes  ;  wherens  witli  all  the 
other  inhahitants  of  the  caven,  disune  by  itself  weeriis  to 
have  done  it.n  work. 

It  is  difficult  to  imairine  condition**  of  life  more 
similar  than  deep  linie-tfine  cavern-  under  a  nearly 
similar  climate;  so  that  on  the  common  view  of  ilu- 
blind  animals  havinir  l)een  separately  created  for  the 
American  and  Kurope^n  caverns,  close  similarity  in 
thc'r  orji'ani.satioii  and  aiRnities  mitrht  ha-.t-  tieen  ex- 
pected ;  liut,  as  Schiodte  and  others  have  remarked, 
this  is  not  the  case,  and  the  cave-insects  of  the  two 
continental  are  not  more  closely  allied  than  mijrht  have 
hecti  anticipated  from  the  i.'-eneral  re.si'mhlance  of  the 
other  inhabitants  of  North  .\merica  and  K.urope.  ( )n 
trv  view  we  nnist  suppose  that  Anicrican  animals, 
havinjr  ordinary  powers  ot  visi(»n,  slowly  mitfrate.j  by 
fiuc(<'ssive  ireneratioiit;  from  tlie  outer  world  into  the 
deeper  and  deeper  recesses  of  tlie  Kentucky  cave-,  a." 
did  Kuropean  animai.s  into  the  caves  of  Kuro[.e.  We 
liave  some  evidence  of  this  irradation  of  iiabit  ;  for, 
a.s  Schiodte  remarks,  'animals  not  far  remote  from 
ordinary  forms,  jirepare  the  transition  trorii  iitrlit  to 
darkness.  Next  follow  those  that  an'  con.structc(!  for 
twiliirht;  and,  l.-utt  of  all,  tliosc  destines!  for  total  dark- 


12f5 


ON     11!  K    ORKJIN    OK    S1'K(  IKS 


I 


iiess.'  |}\  llif  time  lii.it  an  aiiiiii.il  liad  rcicliod,  atler 
nuMilu-rlessi  ir''fH'r.it!nns,  tlic  dci'j>t'-t  ^('<•c^s«•s,  clHuse 
will  oil  tliis  view  h.ivti  nmro  nr  ic><*  p<»rft'ctly  oliiitei- 
at«'(i  it>  oves,  ami  rutural  «.»'lfcli(.ii  wiil  «»fU'n  have 
«'lK''ti'(l  otliiT  cli.mijt'-,  smli  a>  ai  iTicrc.-ise  in  the 
l»?u;jlli  of  tlio  aiit.MiriH'  or  ['.ilpi,  a-  a  <'oii!j»('iiK,-i!ioii 
for  itiitnii'-i-..  Notu  ilhst.-iii(iinir  surh  niomticatiori,-, 
w»'  tmclit  cxfK'ct  stiil  to  >-,■(»  in  -h,.  en  .'-animals  of 
AriuTica.  atrniiti(<>-  to  lin-  otiu-r  iiiii,ili.taiit>-  of  that 
ci'T,.  iiiMl.aiid  111  tiiosfc  u;  hiHii[ii',  lo  tht'  ii.hainiaiiL>» 
of  tie  Kurnj.faii  < oiititient.  Ana  tli.-i  i^  the  la^i-  with 
NotiM'  of  tlj«'  Aiii.  ■■I'Mii  cavt'-aiiiiiial  ■.  a-  I  I  .  ,i-  from 
I*rn;c-.^(ir  I  >ana  :  ri;;ii  Mime  oi  tlu'  I'iun.;,,  ,u  i  .-tNO 
in-i'i-;  .in*  v«'rv  (1.1-..'!^  allied  t<i  tlinsc  oi  tlic  -  .rrriuud 
lur  ('"'iiitry.  It  \M,  ilil  \>f  TitoNt  liiiiiiuli  t<i  i:\\v  anv 
rational  expliiatioii  ot  thf  altinitifs  of  ihe  i)li;i.l  ravt^ 
animal-  to  tlit-  other  luiialiitaiits  of  lin;  tuii  contiiicntf 
on  tiic  oniiii.iry  vi«'W  ot  tiioir  indijiciidiMit  crcafion 
Thai  -rvc  ill  (i!  tiiP  iuhaliiuiii'-  of  luv  r:>.\i^s  ot  tli«'  (  »id 
and  N'i'W  W  orhN  ^lioiild  Im  (•lo-><'iv  ndatt'd.  we  ii.  j!ii 
«^\]i'i:  irorn  tl,c  wtdl  -  ktiowii  rtdatioiisl.i  ji  of  mi,-,i  of 
ihi'ir  otinT  |irodurtiitiis.  lar  tiom  fjMdiii::  ara  >ur 
pri-»'  thai  >omi'  ot  the  <a\«>- animals  -houid  ho  very 
anoiiiaioiis,  i-  Atri-si/,  ha^  ri-markfii  ;n  r«'L'ard  to  the 
hlinii  ti-li.  tin-  Aiird  V  u|'-i-,  and  a-  is  the  ca-r  v\itii  ilu- 
hli'  d  l''ii:«'ii.-  U;!h  rcfcrt'.i.i'  to  the  n-ptih'*  of  l-.iiroiie, 
I  a'li  only  surpri.-ed  that  iiioir  wrerkv  of  ancifiit  life 
have  not  In'en  preserved,  owiuu:  i"  Mh-  Ic^*  -.  . i-rc  ir.in. 
pi'ti'ii.ii  to  wiiiidi  the  iiihaiiil;i!;t>  ot  tia'^t'  U  iri'.  al'odc> 
will  prolialdy  ha\ ,-  hi't-i!  vxpo-ed. 


A'l-ti'inriX'i'uii,.  iiahit  i>  hi'r»'oi;ary  \\  itli  [daiits.  a? 
in  'iic  peruul  o'  lioweriu;:,  in  liir  :imoi,nt  of  rain 
reijuiviti-  lor  r><-i-d-  to  t;t'riinnatt',  iii  ihf  time  of  -Ict'p. 
etc.,  and  ihi.s  nails  me  to  sa\  a  h'v\  word^  on  atciima- 
tisaM.in.  As  it  i^  fxtronudv  i-ommon  tor  ^p<•<  i«.s  ot  tlie 
HAiim  i^ontiB  til  inii.'ilist  \imv  i  iit  and  ii'r\  told  count rio.. 
and  a>  !  ludieNC  that  all  the  >pecu'«.  <ii  the  same  ccnus 
have  di'M'i-nded  irom  a  ^iiiiile  parent,  if  th  -  view  be 
corn-il,  acclimatis;ition  mtiKl  i»e  re.idiiv  eiieiU'd  dariujr 


F.AU  J>   (»F   VARIATION 


1-27 


l(>nfr-coiitiiiUf(l    (ic^coiit.        It    i^J    JHitnriuis    tlwit    r.icli 

fjHJcies    i-;    .'ni.iptt'il    Ut    tlie   i-lirtiate   ot    ;t<    i>wn    Ikmim' 

»pe«'ies  (Vi'iii  at,  .iniir  or  even  Iroiii  a  t<':nj'<'r;.t<'  reiriou 

I'.aiiiuit  euMiirt"  -i  trojiical    clitiiatt',  (tr  oou\t'r-f!\ .      Si> 

aca;!!,  niiiiy  siKcuU'iit   jii.'int?<  caiUKit   einiur*'  a  <i.iin|> 

rliiii.ili!.      llui   ilu'   (it  i.'ri't'  ol    aiiapLiliuii   i)t   ^jn-cn'-.   Im 

'.lit*  ('litiKil>'>i   iiinicr  « Inch   tin*}   liv«'  i«  <itti-i!  ovorrati"!. 

\\  r  t:ia\   i;ii«'r  Uiis  irom  our   ii  <'<jiifiit   iuai'ilitv  to  ]<:' 

•  iiri  'Aiii-ilifr  or  i.nt  aii  irii|.ort«'(i   j.iant  wili  einiurt-  our 

I'liiiiatf.  aii'l    irmr.    tii»-   iiuiiiiicr  «>t   |>i.\rit»  a!:ii    ;iiiirnal.i 

tiroiitht  Iri'iii  waiiiuT  couutru*?  wliuii    Iutc  f!iii>\   troo'i 

licailli.       \\  »>   l.a\f    r»M-oii    to    ItclitMi'  Inat   ^pi-.  u--    \u    > 

ffUiU'  of  nature  an-  iiitiilru  iij  tdrir  raMirt'>'  tiv  the  roni- 

p.'f.tioM  of  otliiT  umaiiic   lt«iiiirs   (juitc  a.-   iiuu-h   as,  n; 

iiion-  than,  hy  ail.ipJaliori  to   jiartii'ul.ir   I'li.'iiati's.      Iliil 

\'.  ht'tin  T  or  ii'H  tilt"  achiptalioii    In*  L'lMitTiilh    vi-iy  rlosi- 
.    : ;.i ...        .         .  ■  .     .,i'  .  . 


tln'ir   l)ec(iiii'.ii' 


.  Ill    tiu'  ca.-t    o;   -'iiu.'    lev*    phijit.-. 

-.      _.  to  a   ciTtain   exti'Jil.  riatuia.ly  hahiti; 

ate<i  to  ililit-n-iit  t'Tripfnitiirt'^,  or  hi'<  nrni!i_'  ai'i'liriia- 
ti-»'(i  :  thu.»  thf  [liiii-.-  ami  riiodociiiiuron;*,  rist-ii  iVi' 
-ml  «'r)lh'rli'ii  hy  I»r.  Hooker  Iroiii  trt'**.-'  irrnvv  ii^'  ai 
ijilicrtut  iifii' 'itH  on  thf  1  lunala\a,  «iTf>  toumi  in  tlii.s 
I  'jntij  to  j>ossf-.>-  tlitiiTt'nt  roiistitiiiionai  poHtT?"  of 
r«'*i>linir  cnhl.  Mr.  Mun  ail*.'-,  iiito.'-iii-  ine  'hat  he  fias 
oi»er\(-(l  >«iniiiai  tart-  in  (  cvhin.  aiut  ai.i.o.cpi^  nh^rr 
\alioi,v  h;>\e  fn't-n  riiailo  hv  .Mr.  11.  (  .  W  at-on  on 
Liirnjic.iii  sjitTu")  of  jiLaiil-x  liroutrht  from  thi*  A/orp- 
!o  Ln^laiul.  In  rt'i.Mrti  lo  anunai-.  .■.t">'frai  niithentii- 
i-a-'cs  ,;oui<i  lit'  fiiviM  of  .<]>t't"u'*  VMihiii  hl^to^ll•al  tune"' 
tiaviiiir  larufly  cxtendeii  itieii  rant.'f  from  wariiit-r  to 
i:t»<ih'r  latitu(ii'>,  an'l  con\('r*oly  ;  iuit  we  <!o  not  j.o-i- 
tiveiy  know  lliat  tlit'se  animal.-.  \vt'n>  -.trii  Uy  h<1.ij.u«1 
to  lhc;r  native  cliiiat*',  l)ij;  m  all  irnlmary  ca-.'^  \m' 
a.'^sunie  such  to  !ie  tiie  ca.se  ;  nor  lio  we  kno«  th.it  thev 
ha\e  suhseijiHMiliy  hetoiiie  a<."Ciimali-e<l  lo  thi-u  iit-w 
hume>. 

A.>i  1  iielio^e  that  our  tioinestic  animal-'  were  orijin- 
ail'.  cho>-«Mi  l>v  linen  iiiMit  man  In-tau-e  tiiev  we.i-e 
li-efijl  and  hreti  reaiiil)  under  confinement,  an<i  n.>l 
because  itiey  «ire  ^i.bse.jueutly  lourui  ca]>ihi.     .f 


;ar 


i2H 


ON    TFIK    OIUGIV    <  )K    bl'W'ILS 


extciKlctl  trari>;,i»rt.ilin:i,  !  think  th<'  rominou  arui 
extraoriliri.iry  <njiru"ity  iii  lur  iiMni«?^tir  aniinrils  oi 
ii.)t  OTily  witli-t.in;iiriLr  *'in'  mo^f  ditiert'iit  <;liin.it«'>;  lnit 
of  beiiiL'  }Mrk'ttly  tortile  (n  far  -everor  t«'st)  umlrr 
thorn,  iiiav  ^f  'iscil  as  riii  ari,'!iTnf'!if  t!i;it  a  l;i!;,''e  pri>- 
-)orti«)n  of  «;th»>r  anim  il>,  riuw  in  a  fctatr  of  ii.ii  iro, 
'  oiild  easily  l»«  tiroUizlit  to  U-ar  si'U'Iy  dit^'tTout 
rlimatos.  We  Tiin>t  not,  bo.vrwr,  jui-h  !}ip  Min>- 
^niii^r  ari^^uiut'iit  too  tar,  on  account  ot  the  [iroii;il);i' 
orii:in  (it  ■jdiik!  <if  ftiir  lionu'stic  aninMl<  from  Ke\eral 
••villi  storks  :  tin'  Mood,  t'or  in^t.info,  <  :  i  t:ojiical  and 
arctic  wolf  or  wild  d"ir  iii?.y  piThrtji-  !>e  wnnuflrd  in 
our  dotju'st'r  lirci'ds.  I  lie  rat  aiid  :iiou-<'  laininf  Ki> 
ro!isidert'i!  as  dniii-'- ■  ic  iTiitnal-.  (nil  thry  h.i\<>  i)t'i'n 
tri.n^jMirted  by  man  to  .n:t;iy  pait-  of  tin'  wurid,  ai'd 
n"W  li:\ve  a  far  v^idrr  -iii^-e  tlian  ai  y  mhrr  rodoiit, 
living  fr»'o  under  flic  <"o!d  cliniatc  of  Karoe  in  the 
ncr  'ii  ani.i  ot  tin*  Kalklaiuls  in  thf  -outh.  and  o.n  many 
isjanils  \u  tlio  torrid  zoni's.  llcnr''  I  an\  inrLni'ii  to 
look  at  adaptation  to  any  special  ijimato  as  a  ijuality 
readilv  u:r;iftt'd  on  an  innHtc  wide  ncvr.iiity  of  (•on^ti- 
tutioii,  whii  !'  is  common  to  n,o~t  inimaU.  ( )n  tin;! 
V  it'~",  thi-  .•;i])a('ity  of  fidurinji  the  most  ditfere!;t 
tlimatos  t>\  man  himself  and  hy  his  domestic  animals, 
aii<!  sucli  fai'ts  .is  that  former  Epecies  of  tho  elepliant 
and  rhinoceros  were  c;!paidc  of  endiiiny  a  tjlacial 
cliinafe.  's  iMTcas  tiie  liviii;f  si>eCit-^  are  i  ov  all  tr"p:ca' 
f,r  siih-trojiical  in  their  hatiits,  ()uy:ht  not  to  he  looked 
at  as  anonialiiv-,  Imt  meroiy  as  examples  of  a  very 
omnion  rlo.Mi»ilitv  of  constitution,  brouirht,  under 
peculiar  !irciimstanc«'S,  into  play. 

How  much  ot  the  acciimai  isatioii  of  Ppecits  to  any 
peculi.if  vlimate  is  due  to  mere  liahit,  and  iiow  much  t<» 
tho  isatural  selection  f>f  var'et;o-  havin.r  dj*'crent  iiin'-.'e 
.•(instituli'Mis.  and  liow  much  to  both  main.-  cimiltiiitil. 
i«  i  'prv  oltscurc  i|uestion.  I'liat  hai>/  or  custom  ha- 
some  inlluence  I  nuist  believe,  both  fr  un  analoiry,  ard 
ironi  the  inco>-vknt  advice  trivn  m  arricuitural  work.-. 
«>ven  in  tlie  ancient  Eni-yclop::'iii;is  of  (  hina,  to  be  very 
caulioiis  in   trau^posin^  aniuiais  f'-om   one   d>trict    t^"' 


L.\\V.S   OF   VARIATION 


129 


.mother;  tor  it  i.«  ;i<»t  Iik<'ly  that  iii.iii  slioijld  have  mir 
Cffiled  in  seltM-ting:  ho  many  hr»'e<N  find  sut^-hr»M>d^  with 
<M>:i->titutioiis  specially  titted  fo.-  tlicir  i»wn  districts  : 
tlie  result  rnuiit.  I  think,  be  due  to  iialiit,  <  »ii  tiie  otli«'r 
hand,  I  can  see  no  reason  tmloiiht  that  natural  selntioii 
w  ill  contuiualiy  tend  t<»  procrvr  tlnc^e  individuaU  vtliich 
are  horn  with  constitutions  he-t  adapted  to  their  natun 
countries.  In  treatises  on  many  kinds  of  ciiltivatfil 
plants,  certain  varieties  are  said  to  with-t.ni<i  certain 
ciiinates  hettcr  than  others  :  this  is  vcrv  -trikin::lv 
own  in  works  on  trnit  tree*  puhli^hfcj  in'  the  I'nited 
>t'ites,  in  wtiirh  (frtain  varieties  are  hat-iiiiallv  re.  om- 
mendt'd  h»r  tlie  northern,  and  others  tor  tiie  soutliern 
States;  and  as  most  of  these  varieties  are  of  recent 
oriiTin,  they  cannot  owe  their  coti-titiitionaj  iIilFcrences 
tohahit.  I  he  cp.-j' of  the  .Icrii-.aleni  artichoke,  which 
is  nev»!r  propa;:alfil  hy  scoi,  .inil  (»f  which  «  <iti-.»-,j;,,iitU 
new  varieties  have  not  heeii  produced,  has  even  heeii 
advanced  tor  it  is  now  as  tt-nder  as  ever  it  w.i^  .is 
proviiiif  tliat  acclimati-.ition  ciniiot  I  .•  ,.t••^.,•tcd  !  The 
case.als(».  of  tlie  kidney-hean  has  heen  otten  cited  for  a 
similar  purpose,  and  'Aitii  min-h  irreater  weiirht  ;  hut 
until  some  (»ne  will  sow.  durinir  a  score  of  L-'einration.-. 
his  kidiiey-heans  so  early  that   :t  ver\   lar_i«   i>roportion 

are  destroyed    t-y  frost,  and  then  colle.t  ,i    trom    tlie 

few  survivors,  with  care  to  prevent  a<-ci(!enf.i!  cro-ses, 
and  then  attain  t'et  seed  troin  the-e  seedlin^rs,  with  the 
s.'ime  pre<aiiti(uis,  the  exjieriment  cannot  lie  saiil  to 
have  heen  even  tried.  Nor  h-t  it  he  -uppo-ed  tliat  no 
liilfereiices  i".  the  con>.titiition  of  seedliiu:  ki>inev-he;in!^ 
ever  npjicar.  for  an  account  has  heen  puhji^lied  how 
much  more  tiardy  some  seedlinirs  appeared  to  ho  than 
others. 

On  the  whole,  I  tlaiik  we  mav  conclude  th.at  hahit. 
Use.  and  (ii^use,  iia\e.  in  some  ca>es,  played  a  consider- 
ahle  jiart  in  the  moditication  of  the  constitution,  atid 
ot  the  structure  of  variou>  or^'ans  ;  hut  th.it  the  effci-ti 
oi  use  and  tiisusc  have  often  t.een  lartjeiv  c«»nihine<i 
with,  and  sometime.s  overmastered  hy  tlie  nature] 
selection  of  innate  varialiona. 


\:v) 


ON    IHK   OIIKJIN    OF   SI'K(  lES 


Ciirrrlntiou  ot  dnnrth.  I  nu'.iTi  hy  tliin  »'xy»res«ij>n 
tli;it  the  wliul«'  <irt:;iiii->atii>M  ix  m>  tied* totrr'tlxT  (lurinjr 
itsLTowtli  ami  (l('V('li>|)ii,fiit.  that  « li«'ii  rili^rlit  v,-iri.itioii« 
ill  ;iiiv  on«'  j»irt  occur,  ami  arc  accunuilatcil  throujrh 
li.'itiiral  .sflt'ctidii.  oth'T  |iar'»  Ix'cotiio  rii'Ml'tii'ii.  I  hi- i<» 
;i  \('ry  iin|i<irtaiit  Mihj<*ct,  nio-t  ini|n«rtt'ctly  uinliT-tO'xl. 
The  riKi'^t  (iliviiiiis  ca>»'  i-.  that  moililicatious  accumiihitefl 
«4(ilcls' for  till'  trooil  of  the  yomiir  or  iarva,  will,  it  may 
Kati'ly  he  ••oiicliidcd.  a:i»'ct  the  structurt'  «)f  the  adult  ; 
in  tlie  same  niaiiiier  as  aiiv  Mialcoiilnriiiatioii  affectin^r 
tin'!  early  «'iiiltr\(),  f;erii»ii'«lv  atfi'cL>*  the  whole  or^/aiiisa- 
lioM  of  the  aiiiiit.  ihe  ve\«'ral  parts  of  t  tie  hody  which 
are  lioino!o;rous.  ami  whicii.  ;it  an  eariy  erntiryouie 
period,  are  alike,  seem  liahle  t(t  vary  in  an  allii'd  ni.umer: 
v.e  see  thi^  in  the  r:_ht  and  h't>  -i<ies  ot  the  hodv  ^aryini; 
in  the  same  tniiiiner  ;  in  the  front  .md  li;nd  lej>.  antl 
evt-n  in  tlie  \:k\\^  anil  liiiih-.  xarvinir  tii:_'e'her.  i^r  the 
lovver  jaw  is  helieved  "o  he  hnmolotrons  with  the  hmh-.. 
I'hf-e  tendencies.  I  do  not  douht,  niav  he  ma'«tered 
more  or  less  com|'!et(dy  hv  natural  s>de<tiiin  :  thus  a 
familv  of  NtaL'"s  once  exivtcil  with  an  antler  only  on  one 
^itle  ;  and  it  thi-  had  Im-cii  of  any  ::reat  use  tothe  hreed 
it  mi^ht  jtrohahlv  hav,'  hem  rendered  permanent  hy 
nat  iiral  ^election. 

1  lomohiirou-  parts,  ;i.s  has  heen  remarked  hy  sotii*^ 
author-",  tend  to  cohere;  this  is  ofteii  ^een  in  monstrous 
plant>;  and  nothin:r  i-  more  common  tiian  the  union  of 
)iom«>lo::ous  parts  in  normal  structures,  as  the  union  of 
the  |M'tals  of  the  corolla  into  a  tuhe.  Hard  parts  -eem 
to  atiect  the  form  of  idionnnir  soft  part-  ;  it  is  helieved 
hy  ooiiu'  authors  that  the  di\ersity  in  the  shape  of  the 
pel\i>  in  hirds  cau~e*  the  retnarkahle  diversity  in  the 
shape  of  their  kidne\-.  ()thers  iiehe\e  that  the  sliape 
of  the  pehis  iti  the  human  mother  it  tluem-es  hy  pres- 
sure the  •'liape  of  the  head  of  the  ciidd.  In  snakes, 
accord. nj-  to  >(hle::el.  the  shape  o:  tlu'  holy  and  the 
maimer  of  sw.iHowintr  dete;-mi:;e  t!.e  position  of  >e\eral 
ot  the  mo»t  imjtortant  vix-era. 

The  nature  of  the  lioiid  of  eorrelation  is  very  trft- 
quently  .]uite  ohscure.      M.  Is.  (ieottroy  >t.  Ililaire  hM> 


LAW.s   OF   VARIAIION 


i.-n 


fnrcihly  remarkcil,  tliat  cert.-im  inaI<oiifi>rir.itinri>*  wry 
frequently,  and  t)iat  others  rarely  rcx'xi-it,  without  our 
hoiiitr  ahU'  to  ^'^it.'n  aiiv  r«»a><i:.  \V  hat  i-aii  \>i'  niorp 
singular  than  t,i*'  rol.it;on  ht'tw»-«vi  iilijc  cyc'  imi  ilr.it- 
iieNj"  in  cats, and  the  tort(ii-;r-.h«^ll  .nhiiir  with  tlu-  Irtnalt, 
■;«'x  :  the  feathfrt'd  fret  an<i  >kin  h«'t.w,.t«ii  th«' out»'r  t«M«H 
in  piiT^'on-*,  and  thf  |ir»>~«'n(«'  ot"  more  or  ii's-;  down  on 
tlie  \ouiiir  hirds  whi'ii  fir>t  hatrht'd,  wit)i  tlu'  futurf 
r<doiir  ot'thnr  {duniii^-t' ;  or.  a::;iiii.  the  r«latioii  h«'tween 
the  hair  and  tertli  in  the  nake<l  I  urki-li  do::,  ttion^'h 
liere  prohatdy  hoiiu)h»iry  coni*'-"  into  jday  '  W  ilh 
re-pett  to  thi-  latter  ca^e  ot  (-(trrelation,  1  tinnk  it  <an 
hardly  he  arciilental,  tliat  if  we  pirk  out  the  two  orders 
of  niainnialia  which  are  n)'i>l  .ilinorniai  in  tlielr  dciTiial 
covfrinif.  viz.  (  t-tacea  (whah's)  and  l-dent.ita  arriia- 
dilloei,  scaly  ant-caters,  etc. ),  tliat  the-e  are  likewi>e 
the  nio«t  ahiiorinal  in  their  tectl:. 

1  know  ot"  no  case  hetter  ada{)ted  to  ^hov*  tiie  iin- 
port.mce  of  the  l.uvs  of  correlation  in  iiiodKyititr  nn- 
port^mt  structure-,  indepeiideiitlv  of"  utility  ami,  t^ier*- 
f'lre.  of  n.itural  seh-ctiuii,  'h.m  that  of  tlie  dirh-niiro 
hetween  the  <iiiter  anrl  intn-r  flowers  in  some  <  ninpo- 
sitous  and  I  inhellit'tTou*  plants.  Kvcryone  know'^  tiie 
difference  in  the  ray  and  central  florets  of,  for  instance, 
the  daisv,and  this  difference  is  often  accomp.in  ed  with 
llie  ahortion  of  part-  of  the  flower.  Kiit,  in  r.ome  (  om- 
povitous  plants,  the  se.-ds  also  differ  in  -h.ipe  .tiid 
sculpture  ;  ami  evii  the  o\,iry  it-elf,  wit!  ^■'  ac«'e— nry 
p.-irts,  differs,  as  lias  het-n  de-crilietl  hy  (  a- -mi.  i'iicse 
differences  have  heen  attnlnitcd  hy  some  authors  to 
pressure,  and  the  shape  of  the  -et'ds  in  the  ray-tloret.s 
in  -onie  (  omposita*  cou»itciian<es  this  idea  ;  hut,  in  the 
ca.se  of  the  corolla  of  the  '  ml.eilif"era',  it  i>  hy  no  mean-, 
as  l)r.  Hooker  informs  me,  in  species  with  the  den-est 
head;,  that  the  inner  and  outer  flowers  most  freijuenlly 
differ.  It  mi^rlit  have  heen  thou^rht  that  the  development 
of  tlie  rav-nefals  hv  draw  in;.'  nouri-hment  from  i-ertain 
other  parts  of  the  flower  had  cau-ed  their  ahortion  ; 
hut  in  >i(ime  (  omjM»sit;e  t  u«'i  o  is  a  difference  in  the  -eeds 
of  the  outer  and  inner  floret-  w  thoiit  any  difference  in 


\  '■ 


i.'{2 


ON     IHK    ()IlH;iN    OF   S|M.(  IKS 


i 


t)i»'  foroll.i.  l*os>iMy,  these  seviT.il  d  ff»'ri'ines  niiy  he 
cniiiit'ctc'l  witli  somo  difrpmirp  in  tho  tlmv  nf  nitri 
meiit  tovririln  tlu>  cciifiMl  .irnl  f>\t«>rii.kl  d'lwrr'-  ■  «») 
know,  at  ltM->t,  tii.iii  111  irri'L'ular  llnncrs,  tliu-**  iitMr«'-.t 
to  tlio  ;ixi-i  .irn  o(tfrH»<l  suliji'ct  'n  [n'lnri'i,  ami  ln'criiiio 
roL'iil'ir.  I  inav  miii.  ri'^  an  Mi-t.iin'<>  ot  t)iix,  atnl  nf  :i 
•itriUiiiir  iTise  (if  nirrrl.itioti,  tli.it  I  have  recently  ob- 
-I'fNiil  m  >i<irjii>  iT'irdeii  pi-lrir^'iiiiiiiiii-.  tliat  the  cj-iitral 
llower  of  the  tni-<-<  often  Nwcs  the  p.itchex  of  <lark«'r 
rulitiir  in  th'»  two  iipiier  fn-taU  ,  :i:iil  that  when  this 
(n  iiir-,  th»>  adherent  in'ctiiry  )■*  ijuite  a'nirtcd  ;  w}ieu 
tho  foh)iir  i'^  ah«ent  frnT)i  <»nly  one  of  tlie  two  upper 
pctaN.  the  ueefary  i-i  only  jtiu<1i  shortened. 

^^'ith  re-p»'ct  to  tlu-  ditleretice  in  the  rnrolla  of  the 
central  and  exterior  tlowers  of  a  head  or  uin''t'l,  I  ilo 
not  tVi'l  at  all  sure  tiiat  ( '.  ('.  Spreimtds  idoa  tliat  the 
riv  ;!orrt^  -ierve  to  attract  in.^cct^.  v\ho'«e  ai-^ency  is 
liiu'hlv  advanta:.'eoij><  in  the  tertili>at ion  of  plant-^  of 
tii>--i>  two  order'^.  is  so  far-fetched,  a-  it  may  at  tir^t 
ipncar  :  and  if  it  !•••  advantatreous,  natural  stdectioii 
rnav  liav«>  curne  into  pliv.  I>ut  in  retrard  to  the  ditfer- 
cnces  both  in  the  nilernal  and  t-Mi-rnal  structure  of  the 
-tM'ds,  which  art'  not  al'.Navs  cMrrtdated  with  atiy  dirfer- 
(Mices  ill  the  llnwcrs.  it  ^.ceni^  iinpo^^ihlc  that  they  can 
he  ill  anv  "av  ad\antaircou->  to  the  plant:  \ct  ill  the 
I 'nilifP'tfra'  Up'-c  di'h'rcnccs  are  of  sm-h  appartMit  iin- 
Ti'irf-ince  t!ie  seels  hcinu'  in  Honie  ca«.t>-,  acccrdin-r  to 
I'auch.  oi'tho-piTinou^  in  the  exterior  tlowers  and 
codo^pernious  in  t}ie  central  tlowers,— that  the  elder  1  )e 
(  andolle  founded  liis  main  division-  o!  the  order  on 
analoiroiis  ditierences.  I  lence  we  see  that  modit'ications 
iif  structure,  \ie-.'.ed  hv  svsteniati-ts  a-  of  h'i:li  value, 
mav  he  wholiv  due  to  unknown  laws  of  correlated 
irrowtli,  And  without  hcinir.  as  far  ns  •.  e  can  se-.',  of  the 
-liiziite-t  service  to  the  species. 

NV'e  may  often  fal-elv  attribute  to  correlation  of 
LTowth,  structures  whicli  are  coiiunon  to  wlmle  trroups 
ot  sjifi-ies.  and  vfhich  in  truth  are  simply  due  to  in- 
iierit.aiH'e  ;  for  an  ancient  proirenitor  mav  have  aei|uired 
throutrli    natur.ll    neleotion  some    one   niodit'ication    in 


LAWS   OK   VARIATION 


1(» 


>»trui'tiiri',  ami,  attt-r  thousaudH  (.{  4f«Mier.itt(iii>.,  stirne 
(illirr  aiitl  iiul»'li»'ii(leiit  niodiruaticin  ;  and  thes«>  two 
nit>tli(ii;iti()iis,  h.'isiu^  l»eeii  triiii'^niitti'd  l«i  a  wlidle  irrtnip 
of  ilfMi-miaiits  with  >iivt>rso  lial^.ts,  wdiild  iialiiriiliy  l'«- 
thoutfiit  to  (>«'  correlated  in  some  iiptessary  niainn-r. 
So,  »u;aHi,  I  <1<»  in't  doulit  that  «»<)me  ap|>areiit  tnrrela- 
tion«,  onurnin;  throupli.tiit  whole  orders,  are  ent.ir<l\ 
due  to  the  niaiiner  alone  in  wlinh  natural  -.•lertion  can 
Hi-t.  For  instame,  Alph.  1  >e  (  andolle  ha*  reniarke<; 
lliat  \vince<i  s«eds  are  never  found  in  fruit»  wliicli  d' 
not  open;  I  -hould  explain  tkie  rule  l>y  the  fact  that 
-eeds  could  not  trradually  hemnio  wiiit'ed  tliioUL'l 
natural  selection,  except  in  fruits  which  opened  ;  ►•<• 
sliat  tlie  individual  pliii's  produciriir  aeed"*  which  weii 
a  little  better  tilted  to  he  w.it'ted  further,  mijfht  e'"'  '■*'> 
advantaije  <)\er  those  producing  M't'd  less  titled  lor 
i!i«per>.'il  ;  aii<l  thin  process  coiild  not  po^^lhly  e*>  '•'■  i" 
Iruit  whuli  did  not  open. 

'Hie  elder  <ie<)tfroy  and  doelhe  propounded,  nt  ahoip 
th«'  >aine  |iennd,  their  law  o.'  compensation  or  halatic,"- 
menl  ot  t,Mi)wtli  ;  or,  as  lM)ethe  expre->ed  it,  '  in  or-ler 
to  Kpeiid  on  one  >ide,  nature  is  forced  to  eoonopiise  on 
the  other  Si'le."  1  think  this  holds  true  to  a  lertv.m 
extent  with  our  doii.e«tic  pro<luclion><  ;  if  nourishment 
t'ows  to  one  part  or  oriran  in  excess,  it  rarely  tlous,  at 
least  in  excels,  to  another  part  ;  thus  it  is  difficult  t" 
iret  a  cow  t<«  trive  much  milk  and  to  fatten  read!) 
rhe  same  varieties  of  thecahhaire  do  not  yield  ahun-iml 
and  nutritious  foliage  and  a  cojcous  siij)ply  of  oil-heannt; 
seeds.  When  tiie  seeds  in  our  fruits  hecome  atroptned. 
the  fruit  it-elf  grains  larjrely  in  si/e  and  quality,  iti 
our  poultry,  a  larj^'e  tuft  of  feathers  on  the  head  i^ 
i^-enerully  aciompanied  hy  a  diminished  comb,  and  .\ 
lartre  i;e:i.rd  *)y  diminished  wattles.  W  ith  species  in  i 
state  of  nature  it  can  hardly  U^  maintained  that  the  law 
is  of  universal  application  ;  hut  many  ^ood  observers, 
more  e-iieciallv  h<>t;inists,  l)elieve  in  it.s  tru'I,  1  will 
not,  however,  here  tivc  any  inst;tnces,  for  I  st)«  harili\ 
any  wav  of  distin^ruishinj;  between  the  effect-,  on  tlie 
one  hand,  of  a   par!    heiiu:  lartrely  developed   throut'h 


••*    V 


If 


I.v4 


(»N    niK    OHM. IV    OK   M'K(  IF> 


natural  m-Iim  'idii  ami  aiioflicr  atni  ailiniiiiiii:  |.arl  Im'  n^ 
ri'ilurcil  li\'  tins  satiM'  proi  •■-■*  m  \<\  (lisiis«>,  atid.  un  th« 
otluT  !  i.!!!,  fin'  a<  ti;.il  M it)iilra*\.il  nt  iii'fritmMit  (roiii 
oiu"  |>;.rt  i)vi;rii,'  to  tlif  excf-.-  of'  LTowfti  in  aiint'lKT  arni 
atlioiniii.'  part. 

I  ••u'«i'«'<t .  aUu,  111  at  -onio  <if  tl.t- 1  i-rs  of  cornMJMisiitinri 
wliirii  hi\«'  hetTi  a<h.iiii  f(l ,  arid  iiKcwise  'tomr  other 
tartn.  riiay  (>•■  nuTL'*"!  uikIit  a  rruut'  i;«'ii»'ral  [»ririripl«', 
i:aiin''y,  that  ii.iturai  -cIiTtiitii  i-.  i ni.tiiniail}  tryitii?  to 
»*<'(iniirhi><>  in  «".t'r\  part  ct  iln*  ora'aMi*,itnin.  If  under 
<"lri'"r«'d  (oniiif ii.n-,  of  jiff  a  >tr  ctiri'  hcforr  useful 
h«'tiifuf<i  li*»-  u-cful,  any  diniriution,  liom  \cr  sltirlit,  iii 
it-x  (l»n»'!i>[»nu>tit,  v\ii!  li»'  «('i/.fd  dn  hv  natural  ^cUmiioh, 
for  it  will  profitth*'  individual  hot  to  havp  it,"  nutniiient 
wa^tfii  in  iHiildimr  up  an  u-t-lc-M  structure.  I  inn  thu<» 
onl\  liiMlfr-tarid  a  lait  with  which  I  was  much  "truck 
v»  hen  ev.iininiti:.'  cirripedes,  atid  of  which  nianv  other 
in.-tar:ce>  eould  ite  iri"-'''!:  namely,  that  \.  hen  a  <irripede 
is  par-isitic  within  another  and  .»  thu-*  protected,  it  lo«e^ 
more  or  le--  coMip!etel\'  it^  own  -hell  or  carnpace.  Thi'* 
i-"  tiie  ca-e  with  the  oiaie  lld.i,  and  in  a  truly  extra- 
ordiii.iry  rnaniier  wit h  the  I'rotfolepas:  tor  the  carapace 
m  ail  other  cirrijiedr-;  eoii-ist-  of  the  three  hitjhlv- 
Mopt.rtant  anti-rior  Sf:."nents  of  the  heafl  enormously 
developed,  and  turni-hed  w  .r!i  trreat  nerve*  and  muscles; 
hut  Ml  tlie  para-iti<-  and  proterteil  I'rotetdcpa^i,  the 
whole  anterior  part  of  the  head  i.><  reduced  to  the  merest 
rudiiueiit  att;vcheil  to  the  lia-^i-of  the  prehensile  anteiuue. 
Ni'vi  i]\f  s:\\  \:iis  of  a  larre  atid  com|de\  structure,  wiien 
rrndere<l  superiluou-'  hv  the  parasitic  hahit-  of  the 
]':•  'colcpa.s,  tiiou:rh  e:(ecti'd  hy  slow  steps,  w.uild  1>«  a 
«lecided  ad^a:lta^'•e  to  e.uh  successive  individual  of  the 
species  :  fur  in  the  -trutTi:!''  t"r  life  to  wliich  every 
atiiTual  i"  e.xpo^e-!,  each  individual  I'roteolenas  would 
have  a  t'citer  ciiauce  of  siipportiiiir  itself,  hy  ie-<s  nutri- 
ment hem..'-  vfa.stod  in  develo[>in:r  a  structure  i.iw 
he«'iitne  ustdess. 

1  hus.  as  1  helieve,  natural  selection  will  always 
succeed  Iti  the  'oriir  run  in  retluciii:.'  and  -avintr  every 
|iart  of  the  ort:aiii.sation ,  as  <oon  as  it  is  renilerod  sup«r- 


l.AUS    (iK    VAKIATH»N 


IM 


U)  t.o  l-irc'ly  )1»'\c1o|km1  hi  n  « (irr»'«jHiii(liiii;f  .l.vri-f. 
Atni.  <<»ii\«'r^»'lv,  tilt!  iiiitiinl  m'1«'<  tmii  lu.iy  |.«Ttf.  tly 
v%rirMJi-<'»'t"l  m  lariTi'ly  <ii'\fl"I'ii'::  .-wiy  ..rcaii.  NMth..iii 
i»<iiiiriiiL'  ik-*  a  iitvi'-sary  .■..nip.Miv.iii.ni  tin*  ri-dmii-.n  nt 
H4)riu'  aiiin'tiitiif  [i.irt. 

It   Hc.-ni".  t(i   l>«'  a   rul«',   i\h   r.iri.trk.-d  l>v    I-.  <.»'.'i'r..y 
^t     lll.iin-.  tx.tli  ill  \arn'ti«"t  .iixl  m  «[m'<-i«-..  thai  whi-n 
.t>i\   |i.iit  or  '<T-j:\u  i-  r»  i>«'iif«l  Miaiiy  tiiin-s   iii  tin*  striu- 
luro  (.Jtli»«  «;«tnf  iiidivi.lii.il  (.-i.-    tl..-  vcrU'l.r:.-  iti  -tLi^e-, 
and  thf  sLiin«Mi«  in  (".lyriiKlroii!*  fio^iT-)  th«'   iimiil..T  i- 
s.iri.il-le  ;     « ln-rt-.x^    tlie   iiiitiil>«'r   nt   the   sanie    |i.irt   i.r 
ort;i!'.  «l'«'ii  'I  <"«tirs   in  h^-er   miriil>«T«.,   i.'   nui-tant. 
'Hn-    >-.ir(i"    rinthnr    and    ^onu-    hnf.ini-t.M    h.i\»'    turtht-r 
remamed    t)i:it   nniltiph-    |«ar;.-.    arc    :i\'<i>   \.Ty    IiaLu*    to 
variatii.f.   in   structur*'.      Iiia-fnuch   a-   thi-<   '  \ri.'»-t.itive 
repftition.'  t«»  i»-«'  I'roC.wsnr  «  )wfn's  .•i|.ri->.i<.n,  •■••vm-  to 
iii«aNi.'n<>t"l<'\v.irirani-ation.th»'  torc!."'iiit.'  i«f>  -irk  ^••^•In> 
cnn.-.l.'d  v»ith  the  very  ircnrr.ii  n|.nii<'ii  <.l  n.ktur.ili-ts 
that  l.t'in;rx  l<»w  in  tht-  .-VaU'  i.t  natireare  tiH.rt*  MiriahU- 
than  thoM-  whiili  art-  nijlu-r.       I  pie-ume  that    !..ui.f» 
m    th;H    ca-^e    moans    that    tlie    se\.T:il    part-    <.t    the 
or^rani-ati.in     have     hr.'ii     hut     littU'     -[..•- lah-.'d     for 
Darticiihir  tunrtions  ;    and  a>  h)iiir  a.-  th.-  -:uii«-  [-.rt  has 
•o  pert. inn  diversified  work,  we  fan  perhaj.*  -•••'  why  it 
-houhl    remain  variahh-.  tiiat    1.-,  why  natural   -eU-.i  ..n 
nliould   iiave  preserved  or  reif.  t.d  each  little  deviat;..n 
of  form  less  earefully  than  w  lien  tlu'  part  h:w  to  serve 
for  one  sperial  purpose  ah-ne.      In  the  same  way  tliat 
a   knife  which   has  to  t-tit  all  -Tts  of  thin-s  may  he  of 
almost  anv   shape;    whiUl  a   tool    tor  s.itne   par'Huiar 
ohieot  had'hetterl.eof  some  parti.ular  ^hape.      Natural 
^eleetion,  it  shoiil.l  never  he  for...tten.  .an  act  on  ea<-h 
part  of  ea.-h  heiiifr,  solely  throu-h  and  for  its  ad-.antatre. 
Ku.limeiit.irv    parts,  'it    has    heen    stated    !■>     -omo 
authors,  and  Thelieve  with  truth,  are  apt  to  he  h  u'iily 
variahle.       U'e    shall    have    to    recur    to    the    t<'"tTal 
Huhjeit  of  rudimentary  and  ai.orie(i  or:rins  ,  an.i  i  v^.ii 
i.ere  onlv  add  that  their  variuhility  seems  to  he  owintr 
to  the.r  ii^ele-siiess,  and  therefore  to  natural  sele.tiou 


m 


136 


ON   Til']    ORIGIN    OF   SPEC'ES 


h.ivinjf  no  j.ovror  t(»  clieck  deviations  in  their  Btructuri-. 
'i  litis  rudiriuMit.iry  jiarts  are  left  to  the  free  pl.iy  of  the 
various  laws  of  trrowth.  to  the  effects  oi  loiitf-tontiiiued 
disuse,  atnl  to  the  tendency  to  rever>ii(»n. 


% 


■r; 


t',ii& 


A  fKirt  (it'frld/H'ti  in  iihy  xpecift  in  an  extraoniiniiry 
di'iiret-  or  imumer,  in  iniiif>nri*i>n  u-ith  the  aninc  purt  itt 
(illit'il  KV"  ii'K,  tfiidK  to  hp  hiijhly  variiihlf.  —  Several  years 
a.ro  I  was  much  stnn-k  with  a  remark,  nearly  to  thn 
ahove  erfei  t,  piililislied  hy  Mr.  W  ater)i<ui<e.  I  infer 
also  from  an  oh-ervation  made  hy  I'roles-or  (*wen, 
with  respect  to  the  leriL'th  of  the  arms  of  the  ouran:;- 
outant.',  that  he  has  come  to  a  nearly  similar  conclusion. 
It  is  hopeless  to  attempt  to  convince  any  one  of  the 
truth  of  this  pro[>ositioii  without  pivin;^  the  lonir  array 
of  facts  which  1  have  oolle«:ted,  and  which  cannot 
[(ossihiy  lie  !iere  introduced.  I  can  <uily  state  mv 
coiniction  that  it  i»  a  rule  of  hijrh  jreiieraiity.  I  am 
aware  of  several  causes  of  error,  hut  I  hope  that  1  have 
niaile  duo  allow;nico  for  them.  It  (diould  he  under- 
stoo<l  that  the  rule  hy  no  means  applies  to  any  part, 
however  unusually  developed,  unless  it  he  unusually 
de\  eloj)ed  in  coinpari>on  with  the  same  part  in  cl(»selv 
allied  ^J)ecies.  I  hus,  the  hat's  wiiiff  is  a  most  almormal 
rttructure  in  the  class  mammalia  ;  but  the  rule  would 
not  here  apl>ly,  l)ec.iu>e  there  is  a  whole  trroup  of  !>.'its 
havintr  winirs  ;  it  would  ajiply  only  if  some  one  species 
of  hat  had  its  »iiii:s  developed  in  some  reniarkahle 
manner  in  comparison  with  the  other  spei-ies  of  the 
same  trenus.  The  rule  applies  very  stron^rly  in  the 
CAse  of  secondary  sexual  characters,  when  <lispl,tyed  iu 
any  unusual  manner.  Die  term,  secondary  sexual 
rliaracters,  used  hy  Hunter,  applies  to  characters  which 
ari'  attaclied  to  one  sex,  but  are  not  dire<"tlv  connected 
with  the  act  of  rfjtroduction.  'ilie  ruleajiplies  to  males 
and  females  ;  hut  as  females  more  rarely  offer  remark- 
able secondary  sexu.il  ch.Tracters,  it  applies  more 
rarely  to  liieiii.  i  he  rule  bein^  so  plainly  applicaide 
in  the  case  of  secondary  sexual  characters,  may  Ihj  due 
to  the  e:reat  variability  of  these  characters,  whether  or 


\^&^ 


LAWS   OF   VARIATION 


137 


not  displaypti  in  any  unusual  manner  of  which  fact 
I  think  there  can  he  little  douht.  Uut  that  our  rule  ih 
not  conftne*!  to  secondary  sexual  characters  i8  clearly 
shown  in  the  t-'i>e  of  herm.'phrodite  cirripedoa  ;  and 
!  may  here  add,  that  I  particularly  attended  to  Mr. 
W'aterhouso's  remark,  whilst  invcsti^oatintr  this  Order, 
and  I  am  fully  cimvinced  that  the  rule  almost  invari- 
ably hol(l<  yood  with  cirripedes.  1  nhall,  in  my  future 
work,  erive  a  list  of  the  more  remarkable  raseu  ;  !  will 
here  onlv  hrieily  irive  one,  as  it  illustrate^  the  rule  in 
it>4  lartrest  appliiation.  Ilio  opercular  valves  of  Hesflila 
cirripedes  (rock  Warnados)  are,  in  every  Ben>-e  of  the 
word,  verv  imjn)rtaiit  structures,  and  they  differ  ex- 
tremely littie  even  in  ditterent  genera  ;  hut  in  the 
several  speiies  of  one  ^enus,  i'yrs;oma,  these  valves 
present  a  piarvj-llous  amount  of  diversification  :  tho 
homolotrous  valves  in  tlie  diHerent  species  l)ein(r  some- 
times whidly  unlike  in  shape  ;  and  theaniount  ot  var.a- 
tion  in  tho  individuals  of  several  of  the  Kpecies  \h 
no  preat,  tliat  it  is  no  exatrireration  to  state  that  the 
varieties  differ  more  from  each  other  in  the  characters 
of  these  important  valves  than  do  other  species  (»f 
distinct  penera. 

As  birds  within  the  same  country  v.irv  in  a  remark- 
aMv  Pmall  decree,  1  have  particularly  attended  to 
them,  and  the  rule  st-cMns  to  me  certainly  to  hold  jrood 
If!  this  class.  1  cannot  make  out  that  it  ap{»lie<  to 
plants,  and  this  would  seriously  have  sliaken  my  Udief 
in  its  truth,  had  not  th»"  jfreat  variability  in  plants 
made  it  particularly  difficult  t<>  compare  their  relative 
decrees  of  variability. 

NV'hen  we  see  any  part  or  «)rean  devclo{)e<l  in  a 
remarkable  dep^ree  or  manner  in  any  opecies,  the  fair 
presumption  is  that  it  is  of  hi;.^h  imjuirtance  to  that 
spe«:ies  ;  nevertheless  the  part  in  this  case  is  eminently 
liable  to  variation.  \\'hy  should  this  Iteso.'  ( )n  the 
view  that  each  species  has  been  indei'enderitly  created. 
with  all  it«  parts  as  we  now  see  them,  I  can  see  no 
explanation.  Hut  on  the  view  that  jfrouns  of  specie* 
have  descended    from    other    sj>ecies,   and    have    l»een 


130 


ON    I  UK    OKKilN    OF   SFKdKS 


!'i 


riiM'iitipd  tlirmiirh  iiattir.il  -ifU-ftidii,  I  think  we  i-,in 
ol»tain  Mima  li^lil.  In  our  (Inrnc-tic  animals,  it"  any 
part,  or  tli«'  whole  ariini.il,  he  rietrlected  fliid  no  splec- 
tioji  Im^  a|tj»lieil,  ihar  jiart  (^tor  iii^tam-e,  the  romi)  in 
tlic  Dorkinu  fowl)  or  the  whoh-  hrenl  will  rea'^c  to  liavti 
a  ncirly  uniforin  character.  The  hreed  uill  then  he 
said  t(t  have  dcL'eiierated.  In  rudirnent.'iry  riruans, 
and  in  thn-e  which  have  heen  hut  little  specialised  for 
any  particular  pnrpo^^e.  and  perliaps  in  p'tivrnorpl.ic 
trroups,  we  see  a  nearly  parallel  n-vriLOii  case;  tor  in 
such  c.i.-es  natural  .•^eiectinn  eitlier  lias  not  or  cannot 
roiTie  into  toll  play,  and  tliiis  the  orj'ain-atinn  is  left 
III  a  tiiictuatine:  condition.  Hut  what  here  more 
especially  coii<eriis  us  is,  that  in  our  «loniestic  animals 
tiiosH  points,  which  at  the  present  time  are  urnltTiroin:;^ 
rapid  chaiiire  hy  continued  selection,  are  al-o  emi- 
nently liahle  to  variation.  I>ook  at  the  hreeds  ot  the 
piireon  ;  see  what  a  prodijfious  amount  of  difference 
there  is  in  the  heak  ot"  the  different  tunJders,  'u  tlie 
heak  and  wattle  of  tlie  «lirferent  carriers,  in  the 
carriatre  and  tail  ot"  our  fantail",  etc.,  these  }>einp  the 
points  now  mainly  attended  to  hv  Kntrli^h  fanciers. 
Kven  in  the  suh-hreeds,  a.s  in  tlie  short-ta«  ed  tumhler, 
it  is  notoriously  difficult  to  hreed  them  nearly  to 
|>erfei  tion,  atid  t"re<iuently  itidividuals  are  horn  which 
depart  widely  from  the  standard.  Iliere  may  l>e  truly 
paid  to  he  a  constant  striUTiile  fr<»in{j  oti  l)etwfen,  on 
tiie  one  hand,  the  tendency  to  reversion  to  a  less 
mollified  .e»ate,  as  well  a.s  an  innate  tendency  to  further 
varialiihty  of  .ill  kiinN,  and,  on  the  othe?  hand,  tlie 
pow«  r  of  steady  selection  to  keep  the  breed  true.  In 
the  lonfif  run  selection  trains  the  day,  and  we  do  not 
expect  to  fail  so  far  iis  to  hreeil  a  hird  as  coarse  aa  a 
eoinmon  tumlder  frotr  a  jrood  .«hort-faced  strain.  But 
a^  louir  as  selection  is  rapidly  ^omg  on,  there  may 
always  Ke  expected  to  he  much  variahility  in  the  ."truc- 
torc  !i!:der=r"irii;  Jn'>'li!icatioT!.  !t  f-irther  derervea 
notice  that  these  variable  chara<ters,  produced  by 
mauH  selection,  sometimes  l>e((>ioe  attached,  from 
causes  quite  unknown  to  us,  more  to  one  sex  than  to 


LAWS   OK   VARIATION 


139 


the  other,  freiienilly  to  tlie  male  wex,  as  with  tiie  wattle 
of  carriers  ai:<l  tlie  eiilartred  crop  of  pouters. 

Now  li't  us  turn  to  nature.  >\'h<'n  a  pstrt  has  l>opn 
ilfveh)ped  in  an  extraordinary  manner  m  any  one 
rtjioiios,  compared  wiili  the  other  species  of  tlie  -vune 
^enus,  we  inav  concl;;ile  that  this  part  has  undergone 
an  e.xtraordinarv  amount  ot  nioditication  since  the 
[leriod  when  the  species  hranchod  utf  from  the  cninmon 
pro{r«'iiitor  of  tJie  t:«'nus  'l"his  period  will  sehiom  he 
reiiKite  in  any  extreme  tletrree,  as  species  very  rarely 
endure  for  mure  than  one  ir«  <>lo^'ical  period.  Aa  extra- 
ordinary amount  of  modification  implies  an  unusually 
lart:e  and  loinj-continued  jimount  of  variah.lity,  which 
has  continually  heen  accumulated  hv  natural  selection 
for  the  henetit  of  the  specie>.  Hut  is  the  variahility  of 
the  extraordinarily-<levelnpe<l  part  or  ortjan  lias  heen 
so  g^reat  and  l<tri:;-continued  within  a  period  not  exces- 
sively remote,  we  mitrht,  as  a  (general  rule,  expect  .still 
to  find  more  variahility  in  sucii  parts  than  in  other 
partis  of  the  organisation  which  have  remained  for  a 
much  long-er  period  nearly  constant  And  this,  I  am 
convinced,  is  the  case.  That  the  stru^fcle  between 
natural  selection  on  the  one  hand,  and  the  tendency  to 
reversion  and  variahility  on  the  other  hand,  will  in  the 
course  of  time  cease  ;  and  that  the  most  ahnormally 
developed  or^rans  may  V-  made  constant,  I  can  M'e  no 
reason  to  douht.  IJence  when  an  ortran,  howe.er 
ahnormal  it  may  be,  has  been  transmitted  in  appnixi- 
mately  the  same  condition  to  many  modified  descend- 
ants, as  iu  the  case  of  the  wini^  of  the  hat,  it  mu.«t 
have  existed,  accord  in;;  to  my  theory,  for  an  immense 
tyeriod  in  nearly  the  same  state  ;  and  thus  it  comes  to 
1)6  no  more  varialde  than  any  other  structure.  It  is 
only  in  those  ca.ses  in  which  the  modification  has  lieen 
comjiaratively  recent  and  extraordinarily  groat  that  we 
outrht  to  find  the  (jmcrntn'e  i^iriahUity,  as  it  niay  be 
called,  still  Dr(»sent  hi  a  hiirh  deirree  For  in  this  case 
the  variahility  will  seldom  as  yet  have  been  fixed  by 
the  continued  selection  of  the  individuals  varying  in 
:he  required  manner  and  det'ree.  and  hv  tlie  continued 


140 


ON   THE    ORIGIN   OF  SPECIES 


r»'je«tion  of  tliosc  teudinp  to  revert  tc  a  tormor  and  lenjj 
Mioilitifd  condition. 

Thp  prinriple  included  in  tlu'M-  n'tiiarks  may  U- 
extended.  It  is  notorious  tliat  specitic  characters  ar« 
more  varialde  than  t^eneric.  To  explain  by  a  simple 
example  what  Im  meant.  If  some  npet^ies  in  a  larjje 
trpiiu^  ot  jdants  had  blue  liowers  and  ^.ome  liad  re<i,  the 
colour  would  he  onlv  a  Kpetific  c  liaracter,  and  no  one 
wtiuld  Ite  surpri>.cd  at  one  of  tlie  blue  ^[lecies  \aryniir 
nito  red,  or  conversely  ;  but  it  all  the  species  had  blue 
thtwer^,  the  cidour  would  iK'come  a  t'^'xric  diaracter, 
md  its  variation  would  be  a  more  unusual  cinurnstance. 
I  ha\e  chooen  this  example  t>ecause  an  explanation  is 
not  in  this  case  applicable,  which  most  naturalists 
would  ad\ance,  namely,  that  wpecitic  characler-  are 
more  sariaido  than  generic,  because  they  are  tiketi 
from  p.irt>  of  less  physiolotrical  imporUmce  than  those 
innimoiily  used  for  dassintr  i:enera.  I  believe  th  - 
explanation  is  partly,  yet  only  indirectly,  true;  J 
«lia!l,  however,  have  to  return  to  this  subjeit  in  our 
chapter  on  (  lassitication.  It  wouhl  be  almost  8U|)er- 
fhioiis  to  a4lduce  evidence  in  pujtport  of  the  alfove 
Ktatenu'iit,  that  specific  characters  are  more  variable 
lliaii  fr,.|i«'ric  ;  biit  I  have  repeatedly  noticed  in  works 
on  natural  hh^tory,  thai  when  an  author  has  remarked 
with  sur()rise  that  soine  xnijxtrunit  or;;an  or  J'art,  whicii 
is  treuerally  very  constant  throutrhout  lar^re  ifr<uips 
ol  sj»eiies,  has  liifffrfd  considerably  ni  closely-allied 
(jpccies,  tliat  it  has,  also,  been  vnriii^'/e  in  the  in<iividuals 
ol  some  lit  the  sjK3cies.  And  this  fart  shows  that  a 
character,  whieh  is  g^enerally  of  ^'•eneric  value,  when  it 
sinks  in  value  and  beccmies  only  of  specitic  value,  often 
tuMuiries  variable,  though  iis  ]diytiioloifiial  importance 
mav  remain  the  ^aine.  S«imeihinfj  of  the  same  kind 
applies  to  monstrosities  :  at  least  Is.  (ieotfroy  JSt. 
liilaire  seems  to  entertain  no  doultt,  that  the  more 
at!  '>rL''i!>  !!orn!-:'J!\'  ditfers  in  tlio  dirterent  sppiie-s  of 
the  same  jfroup,  the  more  subject  it  is  to  individual 
aiioina.ies. 

I  *n  the   ordinary  view   of  each   species  having   l»eeu 


'^^i 


LAWS   OF   VARIATION 


141 


inflepeudeiiUy  cn'.itfil,  why  ^}ll)ulli  tliat  part  of  the 
■tnictiire,  which  rliffers  from  the  same  part  iu  otlior 
iiideperuitMitly-rnvited  speries  of  the  same  tr»Mi'i'<,  he 
niort'  varialilo  than  tli(t-«  parts  whiih  are  ( loselv  .iIiK«? 
in  t)ie  >ev(«ral  speci»'«*.'  i  do  ii«>t  ^«*«>  that  any  explana- 
tion can  ho  tri\»'".  Hut  on  the  view  of  spcries  beiiij^ 
only  «troiitrly  marked  and  fixed  varieties,  we  mi^ht 
surely  e\{»e(t  ti»  find  them  still  otteri  conliniiinjf  to 
varv  in  tli()>e  jiarts  of  their  Ntruetiire  wjiirli  have  varied 
within  a  moderately  recent  period,  and  which  have 
thus  come  to  differ.  <  >r  to  state  the  case  in  ano'lier 
manner  : — the  poinb*  in  which  all  the  species  nf  a 
tfenws  resemhle  each  other,  and  in  which  tliev  d'tfer 
from  the  species  of  8«»me  oilier  serins,  are  called  ireneric 
cliaracters  ;  and  tlie>-e  cl  ;  acte^^  in  common  i  attri- 
hute  to  inheritance  trom  a  common  [•ro^'-enitor,  for  it 
catj  rarely  liave  hap[)e;ied  that  natural  selection  will 
have  modified  several  species,  fitted  to  more  or  less 
widely-different  liah.ts,  in  exactly  tiie  same  matincr  : 
and  as  tlie-e  socailed  ireneric  characters  have  lieen 
inlierited  from  a  remote  period,  since  that  periixl  w  fien 
tiie  species  first  hram-hed  oif  from  their  «'(minion  pr<.- 
trcnitor,  and  suhse<inently  have  iiot  varied  or  come  to 
differ  in  any  deyree,  or  only  in  a  sliijiit  detrree,  it  i> 
tiot  prolialile  that  they  should  vary  at  the  pre.-ent  day. 
( )n  the  other  liaiid,  the  points  in  which  -pciies  diif.-r 
from  otlier  species  of  tlie  same  ffeniis,  are  calleil  specific 
characters  ;  and  as  tlie-e  •.j)ecihc  <'iiaracters  have  varied 
and  I'ome  to  difier  within  the  period  <.f  the  hranchiinr 
off  of  tlie  species  from  a  common  proireintor,  it  is 
j>rnhal>le  that  they  should  <till  often  he  in  some  de;rree 
vanalile.  at  least  more  variahle  tiian  those  parf>  of 
the  oriranisation  whicli  have  tor  a  verv  loiir  period 
reriiaii'<'d  cotist.'int. 

In  connection  with  the  p.'-e-eiit  ^uhject,  I  will  make 
only  two  other  remarks.  I  think  it  will  he  admitted, 
without  my  enterintf  on  details,  that  secoTidary  »ie\iiai 
characters  are  very  vanatde  ;  l  think  it  aKo  will  Ikj 
adinitted  that  sj>ecies  of  the  same  group  differ  from 
each    other    more    widely    in    their    «econdarv    seiu.il 


142 


ON    THE   ORlCilN    OF   SPKCIKS 


»-h.ir.ic»prH,  than  in  oilier  j»;irts  of  llieir  ortr.ini-ation  ; 
(•(»inj>rirf,  for  instime,  tlM>  amount  of  ilitfcreiice  l»et\veeM 
tlie  iiialt's  of  (fallinacfouH  hinls,  in  whifh  sproiKlary 
sfxiial  charat  ters*  are  stroiiL'^ly  disjdayed,  with  tlif 
amount  of  <lirt"tTcn<-e  between  tlunr  females  ;  and  tlie 
truth  of  this  prnpo-ition  will  he  trrantt-il.  'Hie  rause 
of  the  ori;rinal  variability  of  secondary  sexual  characters 
is  not  nrinife!*t ;  hut  wo  can  see  wliy  these  characters 
-ilunild  iKit  have  bpfii  rendered  as  <-onsUint  ami  uniform 
as  (jtlicr  parts  of  the  or^ranisation  ;  for  secondary  sfxual 
characters  have  been  accumulated  by  sexual  selection, 
whii.-h  is  less  ri^jid  in  its  action  tlian  ordinary  selection, 
as  it  docs  not  entail  death,  but  only  {,'ive!<  fewer  otT- 
sprintr  to  the  less  favoured  males.  Whatever  thecau>e 
n»ay  i)e  of  the  variabilitv  of  secondary  sexual  characters, 
as  thev  are  hij:hly  variable,  -sexual  selection  will  have 
h:.d  a  wide  scope  for  .action,  Riid  may  thus  readily 
liave  sucii-eded  in  trivinir  to  the  8{H.'cies  of  the  same 
t:n(Up  a  _'^reater  amount  of  dilference  in  their  sexual 
<  liar.Ktei^.  tiian  in  other  parts  of  their  structure. 

!l  is  a  remarkable  fa<-t,  that  the  secondary  sexual 
differences  between  the  two  sexes  of  the  same  species 
are  t:eiierally  di<piaved  in  the  very  same  parts  «if  the 
or^^ani-;ation  in  wlii.h  the  ditferent  species  of  the  s;ime 
irenus  dith'r  from  each  other.  Of  this  fact  I  will  jrive 
in  illu-itration  two  instances,  the  first  which  liapjien  to 
sl;ind  on  my  list;  and  as  the  ditferences  in  thc-e  cases 
are  of  a  very  unusual  nature,  the  relation  can  hardly 
be  accidental.  The  same  numU'r  of  joints  in  the  tarsi 
;■;  a  character  jfenerally  common  to  very  lartre  irroups  of 
beetles,  iiut  in  the  Knt.nda«,as  Westwood  has  remarked, 
the  iiumi»er  varies  trrcatly  ;  and  the  number  likewise 
ditfers  in  the  two  sexes  of  the  same  species:  a;:ain  in 
fos^oriai  hymenoplcra,  the  manner  of  neuratioii  of  the 
winirs  is  a  character  (»f  the  hitrhest  imi>ortance,  Iwcau-e 
common  to  lari;e  ^:roups  ;  but  in  certain  genera  the 
ncii ration  ditiers  in  the  ditferent  S|)ecies,  and  likewise 
in  tlie  two  sexes  of  the  s;ime  sp«'cies.  ibis  relatKUi  lias 
a  cb'.ir  me.mins'  <»n  my  view  of  the  .subject :  1  look  at 
all  the  speciCvS  of  the  s;ime  jjenus  as  having  as  certiiinly 


LA\\>    OK   VARIATION 


143 


dforeiided  from  the  same  progenitor,  as  liave  tlip  tuo 
twxes  of  any  one  of  the  Pi»«'riex.  (  onsequently,  wliat- 
ever  jiart  of  the  stnicturf  of  tho  cijaimori  pr<>i:eiiitor , 
or  of  its  oarly  <ii'<(«'!i«laiits,  ti«'raTiie  \arial»h3  ;  variatioii«i 
of  this  part  woiihl,  it  i«  liijrhly  protwhlp,  he  taken 
a«lvaiit.i;r<'  of  hy  natural  atid  soxua!  «.-lecti<>ii.  in  onler 
to  tit  tlie  several  -peoe^i  to  t'leir  several  plarcs  in  the 
eroiu)my  of  nature,  ami  like«  :-e  to  tit  the  two  sexe><of  the 
Rame«.pe(:e-.  to  each  other,  or  to  tit  the  males  ami  females 
to  difft'rent  hahits  of  life,  or  the  male--  to  stniiTL'^le  with 
other  males  for  the  [>o>^e*»ion  of  the  females. 

Finally,  then,  I  eomlinie  tliat  tiie  irreater  variahility 
of  speiifie  eliararters,  or  tlio>e  whirh  <iistiiitrtiish  specie.s 
from  sjK'eies,  than  of  trt'iieric  eharai-ters.  or  tho>e  wliich 
the  species  i»o-vc--.  in  common  ;  -that  the  freijiient  ex- 
treme variahility  of  any  part  which  is  (ioveloped  in  a 
Bne<ies  in  an  extMonlinary  manner  in  C'>mpari<on  witli 
the  sjime  part  in  iis  eonireners  ;  and  the  >iiL'ht  deirre*' 
of  variahility  in  a  part,  however  extraordinarily  it  may 
be  developed,  if  it  l»e  oomnion  to  a  whole  trroiip  of 
«})eeies  ;  —that  the  ;rr»'at  variahility  of  ^econdarv  sexual 
characters,  and  the  trreat  amonnt  of  difference  in  these 
same  characters  hetween  closelv -allied  sjM'cies  ;  that 
secondary  sexual  and  ordinary  specific  differences  are 
jfeneraily  displayed  in  tiie  same  parts  of  tlie  ortranisa- 
tion,--are  all  principles  chxely  connected  to^rether. 
All  Iteintj  mainly  due  to  the  species  of  the  same  jrroiip 
having  deseemied  from  a  common  progenitor,  from 
whom  tliey  have  inherited  much  in  common,  to  parb* 
vrliich  have  recently  and  lirir*'Iy  varied  hfin;,'  n\ore 
likely  still  to  go  on  varyin;i:  than  parts  which  have 
lonL''  heeii  inticrited  and  iia\e  not  varied,  to  natural 
sele«'tion  liavin.--  more  or  less  comp!et»dv,  accordin^f 
to  the  lapse  ot  time,  overmastered  the  tendency  to 
reversion  and  to  further  variahility,-  to  sexual  selec- 
tion hein;r  1»'"^"*  ritnd  than  ordinary  s<dection,  — ami  to 
variations  in  the  same  parts  havinjr  heen  accumulated 
by  natural  and  sexual  seieciion,  ami  tia\  iiiir  t>een  ttiUH 
aiiajttcd  for  secondary  wxual,  and  lor  ordin.iry  specific 
purjM)ses. 


114 


ON   THK   ORIGIN    OF  SPECIF:s 


IHxIiurt  Mpirif.i  prrxtntt  atiii/nijon*  inrinfion*  ;  and  a 
inriet^  of  one  xfifiii-s  offfii  a^ttniTwn  noine  of'  thf  rhararterx 
,tf  an  nliied  npfcwx,  or  rrvprtt  to  noruf  of  thf  rlturactem  vj 
an  enrltf  jiroijeuitur.  I'liese  propositioiin  will  be  most 
nvidilv  liridtTstoiMl  hv  !<»(»kiiiir  tn  our  domestic  races. 
The  tiirt«t  distinct  breeds  of  pijfeiMH,  in  countries  most 
witlely  apart,  jiresentsul^-varieties  with  reversed  feathers 
oil  the  head  and  featliers  on  the  feet,  iliaracters  not 
j)os>ies>t'd  hy  the  ahorii:iniil  roek-|»itreon  ;  tliese  then 
are  anilo:;ous  variations  in  two  or  more  distinct  races. 
I  lie  fri'c|uent  presence  of  foiir»»'en  or  even  sixteen  tail- 
featlier-.  in  the  jH)uter,  may  he  oiisidered  as  a  variation 
representing  the  normal  structure  of  another  race,  the 
faiiUil.  I  presume  that  no  one  will  doubt  th.it  all 
su<h  anahtjrous  varinti()ns  are  due  to  the  several  races 
of  the  pijjeon  havintf  inherited  from  a  common  parent 
the  ^.UM(>  constitution  an<i  ten<lency  to  variation,  when 
acted  (in  I>y  siruilar  unknown  intUicnces.  In  the  vetje- 
tihie  kinirdom  we  liave  a  case  of  analo^fous  variation, 
in  the  eiilartred  stems,  or  roots  as  commonly  called,  of 
till'  Swedish  turnip  and  lluta  hatra,  {)lants  whidi  several 
hotani-ts  rank  Jis  varieties  produced  hy  cultivatiiui  from 
a  ctuiunon  parent :  it  this  he  not  so.  the  case  will  then 
he  one  of  anri'.'ijxnus  variation  in  two  so-caUed  distinct 
KjM'cies;  and  to  these  a  third  may  he  added,  namely, 
tiie  common  turnip.  ,-\ccordi:iir  to  the  ordinary  view 
of  each  species  ha\ins;  been  independently  created,  we 
Hhould  have  to  attribute  this  similarity  in  the  enlarged 
Btems  of  the<e  three  plants,  not  to  the  trrn  vnum  of 
community  nf  dex-cnt,  and  a  conse(juent  tendency  to 
varv  in  a  like  m.iuner,  but  to  three  separate  yet  closely 
rcl.itcii  acts  of  creation. 

With  ])itreoiis,]iowever,  we  haveanotlier  case,  namely, 
the  MC(a>.ioiial  appearance  in  all  the  breeii*.  of  slaty- 
blue  birds  with  two  black  bars  on  the  wiuL'-s.  a  white 
riimj..  a  bar  at  tlie  end  of  the  tail,  with  the  outer 
feathers  externally  ed:;ed  near  their  bases  with  white. 
A-  ail  liiese  marks  are  characteristic  ol  liie  parent  rock- 
piireun,  1  presume  that  no  one  will  doubt  that  this 
is  a  raM*  of  reversion,  ar.d  not  of  a  new  yet  analojrous 


LAWS   OK    VARIATION 


14A 


I 


v;iri,ifi(tii  apiMviring'  in  the  several  hret-ds.  We  rnav. 
I  flunk,  cniiti'loiitly  come  to  this  coiirhision,  l)eiMiii)«e, 
a^  we  li.ive  s«'i'ii,  these  coloured  marks  are  eiiiinriitiv 
ii.'ilile  to  apjiear  in  the  crosserl  otf>prinir  of  two  dihtinct 
:iMd  diiTereiitly  coloured  hreeds  ;  and  in  this  ca^Nf  there 
!■*  Mothintf  ill  the  external  ctJiidifions  of  lite  to  raijue 
the  reapjiraraiice  of  the  slaty-ldue.  with  the  several 
marks.  Iieyond  the  influence  «»f  the  mere  act  of  crotif'in^ 
on  the  law-  of  inheritance. 

.N'o  douht  it  i-  a  very  sur|>risinir  fart  tiiat  charattern 
should  reajipear  atler  haviinr  heen  lo<t  for  many,  per- 
ha[»«  tor  hiindr<'(ls  of  ireiicration.s.  Hut  when  a  hret'd 
has  lic»'n  crossed  only  once  hy  some  other  hreed,  the 
oti^prinif  occasionally  show  a  tendency  to  revert  in 
character  t<»  the  forei^'n  hreeti  for  manv  jfenerations — 
sorrif  say,  for  a  do/.erj  or  evei'  a  score  of  generations. 
After  twelve  treneraf ions,  the  proportion  of  hlood,  to 
use  a  comnuMi  ex[)ression,  of  any  one  ance-tor,  is  only 
1  in  U(i41t  ;  and  yet,  as  we  see,  it  is  treneraily  heiieved 
that  a  tendency  to  reversion  is  retained  hy  this  very 
^mall  proportion  of  foreitrn  hl(M>d.  In  a  hreed  whicii 
has  not  lieeii  crosseil,  hut  in  which  hoth  jvirentu  have 
lost  s<irrie  character  which  their  proy^enitor  possessed, 
the  tendency,  wlietlier  strontr  or  weak,  to  reproduce 
the  lost  character  niitrht  l»e,  as  wa.s  formerly  remarked, 
t-r  all  tliat  we  can  see  to  the  contrary,  tnmsmitted  for 
almost  any  numher  of  generations.  When  a  character 
which  ha.s  heen  lost  in  a  hreed.  reapjM'arf'  after  a  ^reat 
niimiier  of  trenerations,  the  most  prohahle  hv{)ot)ie«is 
i-^,  not  that  the  offspriiitr  suddenly  takes  after  an  ancestor 
some  liundred  penerati(»iis  distant,  hut  that  in  each 
*!icies-i\  e  tTPner.itioii  there  l.as  heen  a  tenden<-v  to  re 
produce  the  character  in  (juestion,  which  at  last,  under 
unknown  favouralde  conditiitns,  trains  an  ascendancy. 
For  iiist.tfK'e,  it  is  prohahle  that  in  ea<-h  generation  of 
ttie  Iwrli-piireon,  which  produces  mtwt  rarely  a  blue 
.'iiul  |il;ii'L -Ji^rraij  hlrd,  th«*re  haH  Ise^fi  a  tPTuii^fscv  ip 
fa<  li  generation  in  the  plumaffe  to  assume  this  colour. 
This  \iew  Ih  hypotlietieal,  hut  could  he  su;ijM»rt«d  b\ 
soTiie  fact>»  ;  and   1  can  see  no  more  ahstract  improba- 

i. 


:^ 


m 


11  ^   • 


146 


ON  THE   ORIGIN    OF   SPECIES 


!    V 


bilitj  in  •  tendency  to  prodiue  any  chara»"t«r  l)Oiiin 
inherited  for  an  endlesH  niimUer  of  generations,  tli.nii 
iu  quite  iJhj'IcHH  or  rudimentary  ortfans  beint;,  a«  we  all 
kn<iw  tliem  to  be,  tlius  inherited.  Indeed,  we  may 
MjiiiftiiM»5H  observe  a  mere  tendeiwy  to  produce  a  rudi- 
ment inherited  :  for  instance,  in  the  common  snap- 
drajfon  (Antirrtiinum)  a  rudiment  of  a  fitlh  stJimen  fw> 
often  a{)pears,  that  this  plant  must  have  an  inherited 
teiideiir)'  to  produte  it. 

As  all  the  species  ot  the  same  t'enus  are  suppo^fd,  on 
my  llieory,  to  have  descended  from  a  common  narent, 
it  tiiicht  i>e  expected  that  they  would  O'  isionally  vary 
in  an  analo^fous  maimer  ;  so  that  a  variety  of  one  -pecies 
would  resemble  iu  Home  of  its  characters  another 
species  ;  this  other  sjieciea  heintf  on  my  view  only  a 
well-marked  and  permanent  variety.  Hut  characters 
thus  jraiiied  wouhi  prol»a!)ly  1»«  of  an  unimportant 
ti.iture,  for  the  presence  of  all  important  characters 
will  he  >/-overiifd  by  natur.il  selection,  in  accordance 
with  tlie  diver«»  habits  of  the  species,  ami  will  not  be 
left  to  the  mutual  action  of  the  conditions  of  life  and  of 
a  -iuiilar  inherited  constitution.  It  mitrht  further  he 
expected  that  the  species  of  the  s;ime  pen  us  would 
occasionally  exhibit  reversions  to  lost  ancestral  char- 
ai'ters.  As,  however,  we  never  know  the  exact  char- 
acter of  the  common  ancestor  of  a  irrrxip.  we  could  not 
distiiurui^-h  these  two  cases  :  if,  for  insUuice,  we  did 
not  know  that  the  rock-pigeon  was  not  feather-footed 
or  turn-crowne«l,  we  could  not  have  told,  whether  these 
characters  in  our  domestic  breeds  were  reversions  or 
only  analogous  variations  ;  but  we  mig-ht  have  inferred 
that  the  blueness  was  a  case  of  reversion,  from  the 
number  of  the  markings,  which  are  correlated  with 
the  blue  tint,  and  which  it  does  not  appear  probable 
would  all  appear  totjether  from  simple  variation.  More 
asiM'ciallv  we  mitrht  have  inferred  this,  from  the  blue 
colon  rand  marks  so  often  anpearinL'' when  distinct  breeds 
of  diverse  colours  are  crossed.  Hence,  thoutrh  under 
nature  it  must  generally  l>e  lefl  doubtful,  what  case^ 
are  reversions  to  an  anciently  existinc  character,  and 


^^Ai^m^ti^mm^ 


LAW^   OF  VARIATION 


147 


what  are  new  but  anaIo(roui«  variations,  y^t  w*  ou^ht, 
on  my  tlipory,  nometinioii  to  find  the  varvin^  offsprin^f 
nf  a  sppciwi  aMumintf  charact«»rM  (either  from  reveraiun 
or  fr(»m  analoirniiH  variation)  wliirh  alTa<ly  occur  in 
Hom««  oth«>r  mpmiier«  of  the  saiiie  f^rnup.  And  thi«  un- 
doubtedly is  the  cane  in  natunv 

A  ciinxideralile  part  of  the  diffiouity  in  reroirnixitiif  a 
varii'il»»  p[»t»nps  in  our  »yKtomatic  w«irks,  is  due  to  it« 
varieties  mockitnf,  as  it  were,  some  jf  the  oth«'r  spe<-i»'», 
of  the  fcimo  t:iiiiis.  A  ronsiderable  catalo^^ue,  also, 
rould  he  civeii  of  fnrniH  intermediate  between  two  Mther 
forms,  whirli  themselves  must  he  doubtfully  ranked  an 
either  varieties  or  species  ;  an«l  this  shown,  unless  all 
these  forms  he  considered  as  independently  created 
"jierit's,  that  the  one  in  var;  injf  h.-w  assumed  pome  of 
the  chararters  of  the  other,  ko  as  to  produce  the  intcr- 
nii'diate  form.  Hut  the  best  evidence  is  afforded  by 
parts  or  nrrraiis  of  an  important  and  uniform  nature 
•  '(•capionally  v;iryin»f  so  as  to  acijuire,  in  some  de^free, 
the  charartor  of  the  same  j>art  or  or^ti  in  an   allied 


le  i>a 
a  loi 


species.  1  have  collected  a  lonjf  list  of  such  ca.nes  ;  but 
ho-e,  as  before,  I  lie  under  a  jfreat  disadvanta^re  in  not 
being  able  t<>  >five  them.  I  can  only  repeat  that  such 
cases  certainly  do  occur,  and  seem  to  me  -"ry  remark- 
able. 

I  will,  however,  give  one  curious  and  complex  ciise, 
not  indeed  as  atfectiu^  any  important  character,  but 
troin  m-curriiitr  in  several  species  of  the  same  *renus, 
partly  under  domestication  and  partly  under  nature. 
It  is  a  case  apparently  of  reversion.  The  a.ss  not  rarely 
has  very  di>tin(t  transverse  l»ar«  on  its  letrs,  like  those 
on  tlie  le::s  of  the  zebra  :  it  has  \teen  asserted  that 
these  are  plainest  in  the  foal,  and  from  inquiries  which 
I  have  made,  I  believe  tliis  to  be  true.  It  has  also 
been  asserted  tliat  the  .striin;  on  each  shoulder  is  some- 
times double.  'Ilie  *houlder-stri{)e  is  certainly  very 
variable  in  length  and  outline  A  white  ass.  but  no!  an 
albirio,  liiis  he^Mi  descril>ed  without  either  spinal  or 
shoulder  stripe  :  and  these  stripes  are  sometimea  very 
oUcurc.  or  artually  quite  lost,  in  dark-coloured  ajwes. 


Mi 


i4H 


ON    llIK   (UIKJIN    OK   M'KdKS 


Die  knijl.'iii  of  I'.-illnx  is  h.i d  to  have  fx'iTi  srcii  *  itli  a 
tl(iiili|i«  sliiiul(lfr-stri|>«v  i  lie  liernionus  hrm  no  .olinclder- 
fc  ri|„.  ;  \}tii  tracj'M  (if  it,  an  Mtatrd  hy  Mr.  Ulytli  and 
otlif'r><,  fx'fi-ionally  aii[>»'ir  :  and  1  liavo  Ween  itifnrmed 
>>v  (  'iloncl  INxile  lliat  tli»»  f(»a!>  of  tliiH  >!|KM'ies  <iri« 
/Pdi'rril! V  «<tri|i('d  «(ti  tlie  W'tfs,  ntid  tiiiMtly  «»n  the 
Hl.iMilitrr.  Ilif  i|U<i;.'j'a,  tliMiijrIi  SO  plainlik  li.irrrd  likt; 
»  z»diia  over  tlif  Itody,  i.s  without  hars  on  tli«  h'jfn  ;  tmt 
i  *r.  (Irav  has  (iLririd  oii»>  spiMMnen  witli  \»Ty  disiinct 
•■•  i'r.i-lik«  Sars  un  the  lio«-ks. 

U'ith  r«'sj»oct  to  fhi<  hor^e,  I  liave  rollofti'd  raves  in 
Kiii^la-id  of  the  spinal  >trijn'  in  hursfs  of  the  iim-t  di.« 
Uiirl  hre«'ds,  ami  i»f  <;//  colours  ;  transv;-rv«  |  j,^  ,,„  ^1^. 
!••!>   are  not   ran"   in  diinn,    nioiise-diins,  and    m    one 

ii>ian(e  in  a  c'h«*stniit:  a  faint  shoidder-sitripf  may 
«oini-uni«<o  ho  HfiMi  in  ituii'<,  and  I  haM>  "eeii  n  trai  e  in  a 
i>av    horse.      My  ?on  ni.ide  a  careful  exainin  ition  and 

keti  h  lor  nie  of  a  dun  li<'U;ian  «'art-liorse  w  illi  a  doutile 
f>tri|>«' oil  eacli  shoulder  and  with  le^'-strij-e.s  ;and  a  man. 
■>Th(iir,  1  f.-Hi  implicitly  tru>it,  has  ex.iiiiitied  for  me  a 
small  dun  Welch  pony  with  tltr^-e  short  parallel  ^tiipea 
on  eaih  >lioiilder. 

in  the  north-we^t  part  of  Imlia  the  isattywar  hieed 
of  h(tr»es  is  so  L'ciKT.tilv  striped,  that,  as  1  hear  fro:n 
'  oionel  I'oole,  who  examined  tlie  orewl  for  (he  iudiau 
liove^-ninent,  a  horse  witliont  '^tripes  i.s  not  con'^idereti 
as  piirel\-l)red.  1  He  ■'pine  is  .ihvays  stripeil ;  tli«"  lej-'^are 
treiierally  harred  ;  and  the  shouider-r-tnpe,  whicli  in 
sometimes  doiihle  and  soinotimes  trelde,  is  coinmoii  ; 
the   s(ie  of  tlie  face,  moreover,  is  sometimes  striped. 

1  he  stripes  are  piaine.^t  in  llie  foal;  and  sometinie" 
'|uite  d'-appear  in  »»ld  Imr-es.  Colonel  I'oole  li;w  seen 
hoth  I'r.iv  and  hay  Kattywar  hor^-es  stripeii  when  tirst 
foaled.  I  ha\e,  also,  reason  to  Mispeit,  from  in'ornia- 
tion  iriven  me  hv  -Mr.  W  .  \\  .  KdwanN.  that  with  the 
KiiL'li-h  race-hor-e  the  spinal  stripe  i«  much  commoner 
in  the  foal  than  m  the  tull-irrown  animal.  Without 
here  enteriiitT  on  further  details,  1  may  stvte  that  1  have 
collectetl  ci.ses  of  ley^  and  shoulder  stripes  in  horses  of 
very  diticuut  hreeds,  in  various  couutrie<<  Irou.  hritain 


LAWS   OF    VAKIAri(>N 


14 


to  ^^^st<•rIl  (  liitia;  and  frum  Norway  in  tlic  nurtlt  tnthf 
Malay  Ar«hijK'la;.'(»  in  tli«  wmtli.  In  all  jwirfM  of  tht* 
worlil  tho»<»*  HlriiH's  omir  far  oft.'iu'st  in  duiiH  ami  rn(»iis«?- 
<ititi>  ;  l»v  lli«»  terni  dun  a  lart'e  raiik'«  «»f  tolour  is  in 
'liulfd,  from  one  l'Pt\vi'fii  hniwu  and  Miuk  to  ,t  clo-r 
H|ii>ro;itli  tu  tTPam  >  oiour. 

1  am  a.Nart'  that  (  olonel  Hamilton  >nntli.  wlio  lia- 
V  ntten  on  tlii>  »ijlii«'<'t,  l<oli»*M'n  tlial  tin*  ••♦'vriai  i-reed- 
of  tlio  Imr-o  havf  df-i  <Mid«^l  frorii  srvprai  alMiru'  ".il 
u|K•n«•^  oiif  uf  whicli ,  tlip  dun,  »a«  htri|K*«l  ;  and  tliit 
tin*  il'.ivf  dr-tTiU'd  appfaraiii  )'?<  are  all  <iii«'  'n  an"  u-iit 
rro--r,  witli  the  dun  htork.  lUit  I  am  not  at  all  vit;- 
ft«'d  with  tlii-*  tlipory,  and  should  be  loth  to  apply  it  tc 
l)r*'««(is  so  di-'tinct  as  tlip  ln-avy  Upltian  rart -lior»<  . 
\\'«'Kh  ji"ni»'>,  cidis,  the  lanky  Kittywar  rare,  etc,  m 
haliitin/  the  most  di«tant  parts  of  the  world. 

Now  let  MX  turn  to  the  ei!'eetf!  of  cro^^intr  lh<»  sever.;! 
spet  :e8  i>(  the  hor>e-»reiMiH.  KoUin  as.*erts.  that  'lie 
coiiimon  niule  frotu  the  atua  and  hor!>e  in  particularlN 
njit  to  ha>e  hars  oji  its  lej;x  :  arrordintr  to  Mr.  <Jo-.-e,  iu 
«»Ttain  parts  of  the  lUited  Sta*e.'«  alxjut  nine  out  of  t.;i 
mule"  have  strijied  let,'"*.  I  '>n<e  saw  a  mule  with  iti»  ie  - 
Ko  much  strij't'd  that  any  one  would  at  first  have  thouji^ht 
th.it  it  niu>t  liave  heen  the  product  of  a  zebra  ;  an<J 
Mr.  W.  {  .  .Martin,  in  hi>e\«ellcnt  treati-e  on  the  hor^e. 
ha-  iriven  a  tiirure  of  ji  similar  nuile.  in  four  coloured 
<lrannt;«.,  which  I  have  seen,  of  hyhrids  l>etween  tin- 
ft-""  and  ^eiira,  the  leirs  were  much  more  plainl}'  hanei 
than  the  rest  of  the  Inxly  ;  and  in  one  of  tio'm  there 
w:'s  adouhle  shoulder-stripe  In  l^ord  .Morton  s  famou- 
hyhrid  from  a  chestnut  mare  and  male  ijuairiri,  t!ie 
liyiirid,  and  even  the  pure  off^pritiir  -uhseijuently  pro- 
duct'il  from  the  mare  hv  a  black  Arabian  sire,  were 
much  more  [dainly  barred  across  the  le:r«  than  is  v\cu 
the  juire  ijuai.'L'^a.  i^astlv,  and  this  is  another  mo>>; 
remarkable  case,  a  hybrid  lia.s  been  fijfured  by  I>r.  (iray 
'and  he  int'orms  me  that  lie  knows  of  a  -econd  case) 
ii"in  the  ass  and  liie  heniionus ;  and  this  hyttrid, 
tlioutfh  the  ass  seldom  has  stri{)es  on  hi.s  letf?  and  tlie 
hemiontis  has  none  ainl  hat*  not  even  a  ••houlder-strip*', 


160 


ON  THE   ORIGIN   OF  SPECIES 


I  n 


nevertheleiis  had  all  four  le^  barred,  and  had  three 
short  shoulder-stripes,  like  those  on  the  dun  Welch 
pony,  and  even  had  Mome  zebra-like  stripes  on  the  sides 
of  its  face.  \Vith  respect  to  this  last  fact,  I  was  so  con- 
vinced that  not  even  a  stripe  of  colour  appears  from 
what  would  commonly  be  called  an  accident,  that  I  was 
b  d  solely  from  the  occurrence  of  the  face-stripes  on 
tills  hybrid  from  the  ass  and  hemionus  to  ask  Colonel 
Toole  wliether  such  face-stripes  ever  occur  in  the 
eminently  striped  Kattywar  breed  of  horses,  and  was, 
as  we  have  seen,  answered  in  the  affirmative. 

NVhat  now  are  we  to  say  to  these  several  facts  ?  We 
see  several  very  distinct  species  of  the  horse -genus 
becoming,  by  simple  variation,  striped  on  the  le^  like 
a  zebra,  or  striped  on  the  shoulders  like  an  ass.  In  the 
horse  we  see  this  tendency  strong  whenever  a  dun  tint 
appears  —a  tint  which  approaches  to  that  of  the  i^eiieral 
colouring  of  the  other  species  of  the  genus.  The 
appearance  of  the  stripes  is  not  accompanied  by  any 
change  of  form  or  by  any  other  new  character.  We 
»ee  this  tendency  to  become  striped  most  strongly  dis- 
played in  hybrids  from  between  several  of  the  most 
distinct  species.  Now  observe  the  case  of  the  several 
breeds  of  pigeons :  they  are  descended  from  a  pigeon 
(including  two  or  three  8«b-species  or  geographical 
races)  of  a  bluish  colour,  with  certain  bars  and  other 
marks  ;  and  when  any  breed  assumes  by  simple  varia- 
tion a  bluish  tint,  these  bars  and  other  marks  in- 
variably reappear  ;  but  without  any  other  change  of 
form  or  character.  When  the  oldest  and  truest  breeds 
of  various  «'olours  are  crossed,  we  see  a  strong  tendency 
lor  the  blue  tint  and  bars  and  marks  to  reappear  in  the 
mongrels.  1  have  stated  that  the  most  probaltle  hypo- 
thesis to  account  for  the  reappearance  of  very  ancient 
rhanicters,  is — that  there  is  a  tendency  in  the  young  of 
each  succe."vsive  sreneration  to  protluce  the  long-lost  char- 
acter, and  that  this  tendency,  from  unknown  causes, 
sonietinieB  prevails.  And  we  nave  iu  .  seen  that  in 
several  species  of  the  horse-genus  the  stripes  are  either 
plainer  or  appear  more  commonly  in  the  young  than  in 


LAWS  OF   VARIATION 


151 


the  old.  (all  the  breeds  of  pigeons,  some  of  which  have 
bred  true  for  centuries,  speries ;  and  how  exactly  |»arallel 
is  the  case  with  that  of  the  species  of  the  hor»^ 
(fenns  !  For  myself,  I  venture  confidently  to  look  back 
thoumnds  on  thousands  of  g-enerhtions,  and  I  nee  an 
animal  striped  like  a  zebra,  but  perhaps  otherwise  very 
differei.tly  constructed,  the  common  parent  of  our 
domestic  horse,  whether  or  not  it  l>e  des«-eiide<l  from 
one  or  more  wild  stocks,  of  the  ass,  the  hemionui, 
quacrifa,  and  zebra. 

He  who  believes  that  each  eijuine  species  was  inde- 
pendently created,  will,  I  presuine,  assert  that  each 
species  has  l)een  created  with  a  tendency  to  vary,  both 
under  nature  and  under  domestication,  in  this  par- 
ticular manner,  so  as  often  to  b«nome  8tri{>ed  like 
other  species  of  the  ^enus  ;  and  that  each  has  been 
create*]  with  a  strong  tendency ,  when  crossed  with  s|)ecies 
inhabiting  distant  quarters  of  the  world,  to  produce 
hybrids  resembling  in  their  strip  not  their  own 
partuts,  but  other  s{)ecies  of  the  ^tiius.  'I'o  admit 
this  view  is,  as  it  seems  to  me,  to  reject  a  real  'or  an 
unreal,  or  at  least  for  an  unknown,  cause.  It  makes 
the  works  of  (iod  a  mere  mockery  and  deception;  1 
would  almt'mt  as  soon  believe  with  the  old  and  iirnurant 
cosmogonists,  that  fossil  shells  had  never  live*!,  but  had 
bton  created  in  stone  so  as  to  mock  the  shells  now  living 
on  the  sea-shore. 

:<ummary. — Our  i^aiorance  of  tlie  laws  of  variation  is 
profound.  Not  in  one  case  out  of  a  hundred  can  we 
[■retend  to  assig-n  any  reason  why  this  or  that  part 
tiitfers,  more  or  less,  from  the  same  part  in  the  parents. 
Hut  whenever  we  have  the  means  of  instituting  a  com- 
parison, the  same  laws  ap{>ear  to  have  acted  in  pro- 
ituiiiig  the  lesser  differences  between  varieties  of  the 
same  spe*'ies,aiid  the  greater  differences  (>etween  s|>ecie8 
of  the  same  uenus.     'ilie  external  conditions  of  life,  as 

;  ;::i:ate  arid   lOOu,  cti":. ,  ^^C•:K  tO  have  Uiu::i"-rti  SOHir  slijjht 

nio<lifiratioiis.  Habit  in  producing  constitutional  dif- 
tereucea,  and  use  in  strengthening  aud  disui^  in  weak- 


152 


ON   THE   ORIGIN    OF  SPECIP:^ 


'■     ti  1 
'9'- 

i; 

■''1" 

eniiijT  ami  diniiiiisliiiijf  ortrims,  seem  to  have  boon  more 
potent,  in  tlieir  ••flertft.      Homoi»»;roiiH  parts  tend  to  vary 
in  tlie  same  way,  an<l  homoloifous  {)artH  tend  to  cohere 
Moditieation-  in  hard  part**  and  in  external  parta  SMne- 
tinie^  affect  softer  and   internal  parts.      When  one  j».irt 
is  lar;rely  developed,  perhaps  it  tends  to  draw  n<'uri>;h- 
meiit  from  the  adjoininir  partH  ;  and  every  part  of  the 
Btnicture  which  can  he  siived  without  detriment  to  tlie 
individual,  will   Ik?  saved.      (  lian>:es  of  .structure  at  an 
early  a^e   will   jr^^'ierally  affect   parts  suhsecjufntly  de- 
veloped ;  and  lin^re  are  very  many  other  correlations  of 
jrrowth,  the  nature  of  which  ue  are  utterly  unahle  to 
understand.     .Multiple  jKirts  are  variahle  in  nutjiherand 
in  struct ur5',  perhaps  arisin^f  from  such  parts  not  h.ivinj; 
been  closely  spe<ialised  to  any   particular  fuu.  tion,  .so 
tliat  tlieir  moditic^itions  l.ave  not  been  closely  check«'d 
by   natur.il   selection.      It  is  prohahly   iVom   this   Njime 
cause  that  ortjanic  l»einirs  low  in  the  scale  of  nature  are 
ni<»re  variahle  than  tho>e  which  have  their  w hole  ortran- 
isaticMi  more  specialised,  and  are  higher  in  the  scale. 
Kudimentary  or/;ans,  from  l»ein>f  useless,  will  l>e  disre- 
gard.•<!   hy   natunil   selection,  and  hence  proliahly  are 
variahle.      Specific  characters  -  that  is,  the  characters 
which  have  vomo  to  differ  siiu  e  the  several  s[»ecit><j  of 
the  same  ffenus  hranche<l  off  from  a  common  parent  — 
are   more    variai>le   than  generic  chara<;ier«,  or  those 
which  have  lonjf  been  inherited,  and  have  not  differed 
within   this   same   period.      In   these   remarks  we   have 
referred  to  special   parts  or  orjfans  l»ein>f  still  variable, 
l»e<-ause  they  have   recently   varied   and   thus  come   to 
differ;  but   we  have  al>o  seen   in  the  second   Chapter 
that  the  same  principle  applies  to  the  wliole  individual  ; 
for  in  a  ilistrict  where  many  species  of  atiy  creinis  are 
found— that   is,    wlu-re   there    ban    been    much    former 
variation  and  differentiation,  or  where  the  manufactory 
of  new  specific  forms  hjis  been  actively  at  work — there, 
on  an  aversitf-e.  we  now  find  most  varieties  or  incipient 


able,  and   tiuch  characters  difler  much  in  the  sj>eciefl 
of  the  tame  group.      Variability  in  the  same  p.'irt«  of 


LAWS  OK   VARIATION 


lft3 


the  orjrniii nation  has  (reiiprally  heoii  takeu  ailvautiffc 
of  in  piviinf  se<f»u<lary  sexual  differente*  to  the  Kexes 
of  the  same  Kpe<ies,  and  s|>«<'iHc  diriert^iues  to  th«» 
Keveral  species  of  tlie  •^nie  »feiius.  Any  {>art  or  orjfaii 
'ievelopea  to  an  extraordinary  size  or  in  an  ♦■xtra- 
ordinary  maniior,  in  comparison  with  tlie  sriiiu»  part  or 
orjfan  in  the  allie<l  sp«»cies,  must  have  irorie  tlirntiirh  an 
extraordinary  amount  of  nuHlifuation  since  tlie  ir<'nus 
:irose  ;  and  tlius  we  can  undiMst-tnd  why  it  shouhi  often 
still  ()e  varial)le  in  a  mucli  lii;:lier  d»'i:r»'i»  than  other 
parts  ;  tor  variation  is  ^  lonir-<'ontinut'd  and  slow  pro- 
cess, and  natural  selection  will  ni  such  ca>es  not  im 
vet  liave  had  time  to  overcom*^  tiie  teiidem-y  to  further 
variahility  and  to  reversion  to  a  Icsh  modified  state,  ftut 
when  a  species  with  any  extraordinarily-<ieveloj»ed  oi^^an 
has  l»ecome  the  i>arent  of  many  moditicd  descendants 
-wliii'h  ou  my  view  must  l»e  a  very  slow  proci.?^^, 
ret|uirinff  a  lon^r  lapse  of  time — in  this  case,  natural 
selection  may  rea<lily  have  succee<led  in  ^ivin^f  a  fixed 
character  to  the  or^^au,  iu  however  extraonlinary  h 
maimer  it  may  l»e  devolope<l.  Speines  inheritinij^  ntviriy 
the  same  constitution  fr«)in  a  commou  parent  and  ex- 
posed to  similar  influences  *ill  naturally  tend  to  present 
aualog-ons  variations,  ana  iliese  same  species  may  occ-a- 
•■ionallv  revert  to  some  of  the  characters  of  their  ancient 
progenitors.  Althoutfh  new  and  important  nuMJifica- 
tions  may  not  arise  from  reversion  and  analofou-s 
variation,  such  modifications  will  add  to  the  beautiful 
and  harmonious  diversity  of  nature. 

Whatever  the  caube  may  he  of  each  slijrht  difference 
in  the  otfsprinfj  from  their  parents — and  a  cause  for 
each  must  exist — it  is  the  steady  accumulation,  thrnujfh 
natural  selectiun.of  such  differences,  when  l>eneficial  to 
the  individual,  that  g^ives  rise  to  all  the  more  important 
mo(lification.s  of  structure,  by  which  the  innumerable 
l>einir3  on  the  face  of  this  earth  are  enabled  to  htruj^^le 
with  each  other,  and  the  best  adapted  to  survive. 


CHAPTER    VI 


DIIKIOriTIES    OS    THBOK7 


Dlfflcultlei  on  the  theory  of  descent  with  mfxllflcatlon— Tr«n»ltlon»— 
AtiSfiice  or  rarity  of  tranaltional  varieties— Traniitlnrii  In  hahlt« 
of  life— IXvereifltd  hat)lt«  in  the  same  species— Species  with 
Ji«liit«  widely  different  from  Uiuse  of  their  allies-  oritans  of 
eitreme  perfection— Means  of  transition — Cases  of  dlfWculty — 
Matura  non  faeit  iolturn—nrfHnt  of  »matl  Importance— orfrans 
not  in  all  cases  al)Solutely  i>6rfect— Ihe  law  of  I  nity  of  Type 
and  of  the  Conditions  of  Existence  embraced  by  the  theory  of 
Natural  Selection. 

Ijono  l>ef()re  haviiifi:  arrived  at  thiw  part  of  my  work,  a 
crowd  of  difficulties  will  jiave  occurred  to  the  reader. 
Some  of  them  are  so  g'rave  that  to  this  day  I  can  never 
reflect  on  them  without  l)eins:  sta^jrered ;  but,  to  the  best 
of  myjudffment,  the  greater  nunil>er  are  only  apparent, 
and  tiiose  that  are  real  are  not,  1  think,  fatal  to  my 
theory. 

'l"hese  difficultipH  and  objections  may  be  classed  under 
the  followiiiar  heads .- Firstly,  why,  if  species  have 
descefjded  from  other  species  by  insensibly  fine  trrada- 
tons,  do  we  not  everywhere  see  innumerable  transitional 
forms?  \Vhy  is  not  all  nature  in  confusion  instead  of 
the  species  beintr,  as  we  see  them,  well  defined  r 

Secondly,  is  it  possible  that  an  animal  having,  for 
instance,  the  structure  and  habits  of  a  bat,  could  have 
been  formed  by  the  modifici»tion  of  some  afiinial  with 
whoUv  different  habits?     (an  we  believe  that  natural 


mAvi 


CO!!  Id 


pro-i'scc, 


»i. 


er\t%(h     *i>in/4        rkriTQTia     tki 


trifliii:;  importance,  such  as  the  tail  of  a  jjiratTe,  which 
stirves  as  a  fiv-flapper,  and,  on  the  other  hand,  ori;;»n«  of 

154 


DIFFICULTIES   ON  THEORY 


155 


iuch  wonderful  rtructtire,  as  the  eye,  of  which  we  hardly 
an  yet  fully  understand  the  iuimitahle  f)erfe<tion .' 

hiirdly,  can  instincts  be  acquired  and  modified 
through  natural  selection  ?  What  shall  we  say  to  »o 
manellous  an  instiiut  as  that  which  leads  the  bee  to 
make  cells,  which  has  practically  anticipated  the  dis- 
coveries of  profound  mathematicians .' 

Fourthly,  how  can  we  account  for  s|)ecies,  when 
crossed,  beiiijf  sterile  and  producintr  sterile  olTsprinjf. 
whereas,  when  varieties  are  crossed,  their  fertility  is 
unim{>aired  .' 

Hie  two  first  hear  diall  be  here  discusseil  — Instinct 
and  Hybridism  in  separate  chapters. 

(>ti  tfw  abunu-f.  or  rarity  of  transit ionnl  i^irit-tie*. — 
As  natural  selection  acts  solely  by  the  preservation  of 
profitable  modifii-ations.  each  new  form  will  tend  in  a 
f"ully-stocke<i  country  to  take  the  place  of,  and  finally  to 
exterminate,  its  own  less  improve<l  parent  or  other  lesi*- 
ravoured  forms  with  which  it  comes  into  competition. 
ITius  extinction  and  natural  selection  will,  as  we  have 
seen,  ffo  hand  iu  hand.  Hence,  if  we  look  at  each  specie* 
as  descended  from  some  other  unknown  form,  Iwth  the 
parent  and  all  the  transitional  varieties  will  jreneriUy 
nave  \>een  exterminated  by  the  very  process  of  forma- 
tion and  perfection  of  the  new  form. 

But,  as  by  this  theory  innumerable  transitional  forms 
must  have  existetl,  why  do  we  not  find  them  embedded 
in  countless  numbers  in  the  crust  of  the  earth  }  It  will 
be  much  more  convenient  to  discuss  this  *|uestion  in  the 
chapter  on  the  Imperfection  of  ths  ^eolo^^ical  record  ; 
and  1  will  here  only  state  that  I  believe  the  answer 
mainly  Les  in  the  recor<i  J>einf?  incomparably  less  perfect 
than  is  (fenerallv  supposed  ;  the  imperfection  of  the 
record  being  cliiedy  due  to  ortranic  beinjrs  not  iuhaliitinif 
profound  depths  of  the  sea,  and  to  their  remains  l»einif 
♦'mtiedded  and  preserved  to  a  future  a^e  only  in  masses 
u:  i!«niTncut  Humriuiiiiy  liiJCR  anu  citriir.ive  uj  rfiLBz-^-.-.-i 
an  enormous  amount  of  future  de^n^^tio"  '•>  *'><i  "^^^^ 
foasiIiferouB  msMes  can  be  accumulated  only  where  much 


iftn 


OS  THE   ORIGIN    OF  SPECIES 


I 


st'dinuMit  18  «le|n>^iie(i  oa  tlie  shallow  hed  of  tlif;  ht»5i, 
wlii!-'.  it  slowly  6ubsi(l«-s.  '^lle^e  coutinffi'ticicx  will 
••niuur  only  rarely,  aini  alter  »'n<»rin()usly  lotifj  iiitt-rvah. 
\\  liilst  tho  lied  of  the  sea  is  sUitioiiary  or  is  risiiiif,  or 
when  very  little  sediment  is  heiiiL'  dejin^jted,  there  will 
he  hiaiiks  Ml  our  f;e<dojjital  history.  1  he  crust  of  the 
earth  is  .i  vast  riiuseutn  ;  but  the  natural  eol lections 
have  Imcm  made  only  at  intervals  of  time  inimen-ely 
rem(i;iv 

Hut  it  may  he  urued  that  when  several  chwely-allied 
"{■•'lies  inliahit  the  >ame  territory  we  Hurelv  ouf^ht  to 
find  at  tho  jire-ent  time  many  transitional  forms.  I>'t 
us  take  a  simple  case  :  in  travelling  from  north  to 
Mjii'li  over  a  coiitinent,  wo  generally  meet  at  siicc('<- 
Hive  intervals  with  closely  allied  or  representative 
«|M'cie,-.,  e\ideiitly  fillinif  nearly  the  same  place  iu  the 
natural  econi»my  oi  the  land.  'I'hese  representative 
Hpecio  often  meet  and  interlock  ;  and  as  the  one 
becomes  r.irer  and  rarer,  the  other  hecome>  more  and 
more  treijuent,  till  the  one  replaces  the  other.  Hut  if 
we  compare  tliese  species  where  they  interminjjle,  thev 
are  generally  a.'-  absolutely  distinct  from  each  other  in 
ev«-ry  <letail  of  structure  as  are  specimens  taken  frrini 
the  iiietrop(dis  inhabited  by  each.  By  my  theory  the>o 
allud  species  have  descended  from  a  common  parent; 
aiMi  -iuriu:,'  the  process  of  modification,  each  na.s  \>e- 
cotne  adapted  to  the  conditions  of  life  of  its  own 
reirion,  and  has  supplanted  and  exterminated  its 
oritrmal  parent  and  all  the  transitional  varieties  be- 
tween its  p;ist  and  present  states.  Hence  we  ouKiit 
not  to  expect  at  the  present  time  to  meet  with 
numerouti  transitional  varieties  in  each  retrion,  thoufrli 
they  iiiuHt  have  existed  there,  and  may  be  embedded 
tliero  in  a  fossil  condition.  Hut  m  the  intermediate 
retrion,  having  intermediate  conditions  of  life,  why  do 
we  not  now  find  closely-linking  intermediate  varieties.' 
This  difficulty  for  a  loiitr  time  quite  confounded  me. 
liul  1  liiiiik  it  can  be  in  iarg'e  j)art  eJiplaiiieu. 

in  the  nrst  place  wo  should  l)e  ext.cmely  cautious 
iu   infernnjr,  because  an  area  is  now  cdntiuuous,  that 


'■Mr. 


DIKFICTLTIES   ON   TIIKORY 


16; 


It  ha-i  >><-tMi  cfintiiiuoim  durintr  a  \oue  i»erio«l.  (i«M>l<»tfj 
woiiM  h'.id  MS  to  believe  that  almost  every  r<»iitiiieiit 
li;i-  Keen  broken  up  into  islaiuls  even  duriiiif  the  laf«T 
tertiary  |>er,<i<l»  ;  and  in  surh  inlands  di-^tinct  sjK'ciei* 
miifht  have  h^on  pejiaratcly  formed  without  the  possj- 
h'lify  of  intermediate  varieties  existinsr  in  the  inter- 
mediate ziidps.  Ily  chatitr*.*!  ill  the  form  of  the  land 
.i!id  of  eliiiiate,  n<arine  areas  now  continuotj"!  must 
ulten  have  exi>ted  within  re<ent  times  in  a  far  les.- 
eohtinnoiis  and  tiniforni  toridition  than  at  present 
Hut  I  v*ill  iia>fl  over  lhi>  way  of  eseaj>ini;  from  the 
•litlieiilty  ;  tor  I  believe  that  many  perfectly  defined 
-pecies  have  been  formed  on  strictly  continuous  areas  ; 
lliuiitrh  1  .io  net  <loubt  that  the  formerly  broken  condi- 
tion of  areas  now  continuous  has  played  an  important 
jiart  in  the  formation  of  new  species,  more  espinialiy 
with  freely-crossinjr  and  wandering:  animals. 

In  lookin<;  at  species  as  they  are  now  distributed 
over  a  wide  area,  we  generally  find  them  tolerably 
nmiierniis  over  a  lar-re  territory,  then  becomiiitf  Mime- 
wliit  abruptly  rarer  and  rarer  on  the  contineN,  and 
tiiiaily  disajtpearini.'.  Hence  the  neutral  territory  \>e- 
tween  two  representxitive  species  is  jjenerally  narrow  in 
comparison  with  the  territory  proper  to  each.  N\'e  see 
the  same  fact  in  ascemlinp  mountains,  and  sometimes 
It  is  ijiiite  remarkable  how  abruptly,  as  Alph.  De 
(  aridi>lle  has  observed,  a  common  alpine  species  dis- 
appears. 1  he  same  tact  has  l)een  noticed  by  K.  Forbes 
in  soiindintf  the  dejtths  of  he  sea  with  tlie  dredge. 
To  those  who  look  at  climate  and  the  physical  condi- 
tions of  life  as  tlie  all-important  elements  of  distribu- 
tion, these  fact-  ouirht  to  cause  surprise,  as  climate  and 
lieiL'lit  or  dep'li  trraduate  away  insensibly.  liut  when 
we  bear  in  mind  that  almost  every  9pe<'ies,  even  in 
its  metropolis,  would  increase  immensely  m  numbers, 
were  it  not  for  other  competiii|f  s[)ecies  ;  that  nearly 
all  either  prev  on  or  serve  as  prey  for  other«;  in  short, 
thai  ea»-h  ortranic  beliiir  is  eitlier  directly  or  indirectly 
relate*!  in  tlie  most  im|Mirtant  niantier  to  other  ortranic 


•ein^rs.  we  rtius 


t  st>e  that  the  ranue  of  the  inhabiiaut» 


168 


ON  THE   ORIGIN    OF  SPECIES 


of  any  rountry  by  no  means  exclusively  depends  on 
iriseiHibly  ch.iti{rin>f  physical  conditions,  but  in  larjje 
I>art  on  the  presfnre  of  other  KiH»ci«»s,  on  which  it 
depends,  or  by  which  it  is  destroyed,  or  with  which 
it  comes  into  competition  ;  and  as  these  species  are 
already  define*!  objects  (however  they  may  have  b«'come 
so),  not  b!endin*f  one  into  another  by  insensiJtle  ^rada- 
tiojiH,  the  rarnre  of  any  one  specie^,  dependinif  as  it 
does  on  the  ranire  of  others,  will  tend  to  be  sharply 
defined.  Moreover,  each  sj)ecie«  on  the  confines  of  it« 
ranjfe,  where  it  exists  in  les>ened  numlK?rs,  will,  durinjf 
ductuations  in  the  numlier  of  its  enemies  or  of  itii  prev, 
or  in  the  seasons,  be  extremely  liable  to  utter  exter- 
mination ;  and  thus  its  jfooirra'phical  ran^e  will  come 
to  l»e  still  more  sharply  defined. 

If  I  am  ri^ht  in  belicviritf  tiiat  allie<l  or  represent- 
ative  species,  when  iuhabitiiiff  a  i(»ntinuou8  area,  are 
icenerally  so  distributed  that  each  has  a  wide  ran^jo, 
with  a  coinjiaratively  narrow  neutral  territory  between 
them,  in  which  they  become  rather  suddenly  rarer  and 
rarer;  then,  as  varieties  do  not  essentially  ditTer  from 
species,  the  same  rule  will  pn»bably  apply  to  both ;  and 
if  we  in  imagination  adapt  a  varyinjf  s{)ecie9  to  a  very 
lar^rj.  area,  we  shall  have  to  adapt  two  varieties  to  two 
larjfe  areas,  and  a  third  variety  to  a  narrow  intermediate 
7.one.  'Hie  intermediate  variety,  conse(|uently,  will 
rtxist  in  les.ser  numbers  from  inhabitinjf  a  narrow  and 
lesser  are,i  ;  and  practically,  as  far  as  1  can  make  out, 
this  rule  iiolds  p^ood  with  varieties  in  a  state  of  nature. 
I  have  met  with  strikinjf  instances  of  the  rule  in  the 
case  of  varieties  intermediate  l»etween  well-marked 
varieties  in  the  jfenus  lialanus.  And  it  would  appear 
from  information  pven  me  by  Mr.  Watson,  Dr.  ls,i 
(iray,  and  .Mr.  W'ollaston,  that  jfenerally  when  varietie* 
intermediato  l>etween  two  other  forms  occur,  they 
are  miidi  rarer  numerically  than  the  forms  which  they 
connect  Now,  if  we  may  trust  these  facts  and  infer- 
enres,  and  tlierefore  conclude  that  varieties  linking 
two  other  varieties  toj^ether  have  jfenerallv  existed  in 
lesser  numbers  tlian   the  forma  which   they  connect, 


DIFFICULTIES   ON  THEORY 


169 


then,  I  think,  we  can  understand  why  intermediate 
varietiea  nhould  not  endure  for  very  long  period*;— 
why  as  a  jjeneral  rule  they  hIiouIU  '»«  exterminated  and 
disappear,  Hooner  than  the  forms  which  they  oriKinally 
linked  together. 

For  any  form  existing  in  lp>i-<pr  numWrs  would,  tu* 
already  remarked,  run  a  greaU^r  rliance  of  InMiig  exter- 
minated than  one  existing  in  large  numliers  ;  and  in 
tliii  particular  case  the  intermediate  form  would  !»«• 
eminently  lialtle  to  the  inroads  of  closely-allied  forms 
existing  orj  b<ith  sides  of  it.  Hut  a  far  more  important 
connideration,  as  1  believe,  is  that,  during  the  process 
of  furtlier  modification,  hy  which  two  varieties  are 
8uppo>-»'<l  on  my  theory  to  i>e  converred  and  perfected! 
into  two  distinct  species,  the  two  which  exist  in  larger 
numhers  from  inhabiting  larger  areas,  will  have  a  great 
a<lvaiitat'^e  over  tho  intermediate  variety,  which  exists 
in  gmalU-r  numbers  in  a  narrow  and  intermediate  zotie. 
For  forms  existing  in  larirer  numbers  will  always  have 
a  l>ettor  chance,  within  any  given  period,  of  presenting 
further  favourable  variations  for  natural  sele«-tion  to 
seize  on,  than  will  the  rarer  forms  which  exist  iu  lesser 
numbers.  Hence,  the  more  common  forms,  iu  the 
race  fo"  life,  will  tend  to  U«at  and  supplant  the  less 
common  forms,  for  these  will  l>e  more  slowly  modified 
aii'l  improved.  It  is  the  same  principle  wljich,  as  I 
Ix'lieve,  accounts  for  the  common  species  in  ea«-b 
country,  as  shown  in  tlie  second  chapter,  presenting 
on  an  average  a  ifreater  number  of  well  -  marked 
varieties  than  do  the  rarer  species.  I  may  illustrate 
what  1  n>ean  by  supposing  three  varieties  of  slieep  to 
to  be  kept,  one  adapted  to  an  oxteii>ive  mountainous 
region  ;  a  s<'cond  to  a  cnmparatively  narrow,  hilly 
tract ;  and  a  third  to  ^vide  plains  at  tho  K-.use  ;  and  that 
the  inhabitants  are  all  trying  with  eqtial  steadiness  and 
skill  to  improve  their  stocks  by  selection  ;  the  chances 
in  this  c-a.se  will  \h\  strongly  in  favour  of  the  Kjeat 
holders  on  the  mountains  or  on  tiie  plains  improving 
their  breeds  more  <  uickly  than  the  small  holders  on 
the  intermediate  narrow,  hilly  tract;  and  con»o<jueutly 


\>,i) 


ON   THK   OKKIIN    OF   SI'KCIK.s 


tlif  ittipnnp«l  TTioiiritiiii  or  jil.iin  hr«f(l  will  soon  fakt; 
till*  place  of  tlio  It'ss  iiiiproM'd  Mil  Wrfpd  ;  and  thus* 
the  two  hroe<tH,  whnh  uriyiiially  existed  in  cr«»at<-r 
iiumfnTs,  will  roniH  into  close  cr)r)tact  with  each  other, 
without  t)o»  intwrpositioii  of  the  HiipplaiitiMl,  iriter- 
riiH(ii.ile  hill-varit'ty. 

To  sum  up.  I  lu'lieve  that  Hpecio^  come  to  l»e  toler- 
tiiiy  wcll-dt'liiifd  ohjects,  and  do  not  at  any  one  p^Tioi! 
present  an  inextric.il)le  cliaos  of  varsintf  and  \utf>,: 
mediate  links  :  firstly,  hecause  new  varietie>»  are  vet  . 
slowly  formed,  fVir  variation  is  a  very  slow  procestJ. 
and  natural  selection  can  do  nothiti  until  favourable 
variations  chatice  to  <»ccur,  and  mail  a  place  in  the 
natural  p<<lity  of  the  country  can  l»e  U>tter  filUxl  by 
some  mod  ideation  of  some  one  or  m(»re  of  its  itihahit- 
ants.  And  such  new  places  *ill  deftetid  on  slow 
chang^es  of  climate,  or  on  the  occasional  imtni.'ration 
of  fii'v*  inhahitatits,  and,  prohaMy,  in  a  still  more 
important  de^'ree,  on  some  of  the  old  inhahitanta 
he.oinintr  slowly  modified,  with  the  new  frtrms  thus 
prxiliired  and  the  old  ones  actinif  and  reactinjf  on 
each  other.  So  that,  iti  any  one  retrion  and  at  any 
otie  time,  we  oujjht  <»nly  to  see  a  few  species  pres«»-  m^r 
slitrht  modifications  of  structure  in  some  de^re  »er- 
maiient  ;  and  this  assuredly  we  do  see. 

>ecoudly,  areas  now  continuous  must  often  have 
existe<l  within  the  recent  period  in  isolated  portiotis, 
in  wlii(h  mai.y  forms,  more  esjiecially  atnontrst  the 
clasM',s  which  utiite  for  each  birth  ami  wander  much, 
may  have  se|i.irately  U-en  rerulered  suthcientiv  distinct 
to  rank  as  rrprcsentitive  species.  In  this  case,  inter- 
ni"diate  varieties  between  the  several  representative 
sjiecie.s  and  their  commoti  parent,  must  formerly  have 
e\isteil  in  each  broken  jMirtion  of  t!ie  land,  but  these 
links  will  }ia\e  bijcn  supjdanted  and  exterminated 
duritiK  the  process  of  natural  selection,  .so  that  they 
will  no  lontrcr  exi«t  in  a  livin;r  state. 

ilurdiy,  when  two  or  more  varieties  have  been 
formed  iti  dilTerent  p.u-tioiis  of  a  strictly  contmuoue 
area,  intermeil-ate  varieties  vrill.  it  is  probable,  at  fir*t 


DiFKK  I  LIIKS    (»S     fllK.oUV 


II 


bAv»>  li»'«M>  foriniil  ill  tin*  iiitfrrm  li;it»'  zoiu's,  '  ut  tlu'y 
will  (jrtMMT.'iUy  lia\»*  had  a  ►•hnrl  dunitioii.  lor  flu'se 
iiit»«rmt'(iiMt»>  virifi'fs  will,  frotii  rf;i>()ri-.  alrt'.nly  iis- 
hi;,'iieii  (luiiiH'ly  trotii  wh.it  wp  know  (if  tho  actii.il 
liintriliiititm  ot  fiK-fly  allu'ci  or  rcprrspntative  K|HH'it'<, 
aiiil  likf\*i.»»  uf  ;iiknMwU>«ltf»'il  vari*!ti«'>),  exint  in  the 
itit»'rrin'iii.it«'  ZDiitw  in  lossor  ininihiT-  tliin  the  vari<'ti«>fl 
wliirii  thi-y  irtid  to  fotiMKrt.  From  thi.-*  caune  a!  le 
thp  iiiit'rm«'fliate  vari»'ti»'s  will  1)©  liahle  to  accidt'i.  il 
•'xtfrrniiatioM  ;  and  (liirin;;  tlie  process  of  MirtiuT 
niixtitHation  thr<»iii;]i  natural  >cl«><-ti(i[i,  thev  will 
aiiiMist  fiTtaitily  J>e  hoaten  and  >-ij|i|ilant 'd  by  the 
(■•riiis  Hliiih  tlu-y  «'niiiiect  ;  for  llit -.«  from  existitii; 
in  trrfatt-r  luinilirrs  will,  in  tl  ••  airirn't.,itv ,  iir»'>4'nt 
ui(ir»*  variation,  and  thus  he  further  itn|in»v««d  Inrouch 
ualiiial  -»'h'»tion  and  jr-iin  further   kdvantat'«'«*. 

l-i>.ily.  lo'ikni;:  n(»t  to  any  one  lime,  'ut  to  all  time, 
it  my  fiifory  Ite  true,  niiniherle>s  interiiudiate  varieties, 
linki!!.:  niiist  rlo^ely  all  the  Kpecies  of  the  same  croup 
toiTi'tiicr,  miivt  a^-iiredly  have  existed  ;  hut  the  very 
>ro.f»s  of  natural  <elerli(>u  co!i>tantly  tends,  as  h;is 
>een  so  <»t"len  remarked,  to  exterminate  tlie  parent- 
tornis  and  tlio  intermediate  links.  (  <nise<iuently  e\  i- 
ilence  of  their  luriner  exi-iteine  could  be  found  onlv 
amHi:jr>t  fo>i>il  remains,  which  are  preserved,  as  we 
xhall  in  a  future  cliapter  attempt  to  ^iiow,  iu  an 
extrcMifly  imjK'rfe«  t  and  intermittent  reror<i. 


"ii  thf  (,riii\)i  and  trtnuitioitu  of  org  inic  hfingn  uith 
fiiilinr  hnhits  iind  atructure.  —  It  has  been  a.sked  by  the 
('iiponents  of  such  views  as  I  liold,  liow,  for  iusLanre,  a 
land  carnivorous  animal  c«)uld  ha\e  been  converted 
into  one  with  aijuatic  hahit-s  ;  for  how  coulil  the  animal 
HI  its  tran-itional  ^tate  have  subsisted?  It  would  be 
c\Lvy  to  sliow  thiit  within  the  same  gT<n][»  «-arnivorou!« 
animals  exist  havintr  every  intermediate  ;rrade  between 
truly  aijuatic  an<l  ^tril•tly  terrestrial  habits  ;  and  as 
each  exi~t.s  by  a  strujrifle  for  life,  it  is  dear  that  ea«h  is 
well  adajiied  in  it-  habit,s  to  its  place  in  natu'-e.  l/iok 
at   the   Mustela  visou    of  North    America,  whicJi    luw 


i»;2 


ON    INK   OKKWN    OK   SI'K(  IKS 


welilioil  r»>»*t  .iihI  wliich  r»•^«'rnf^lo^  nti  ott»»r  in  itit  fur, 
!<li()rt  \*'HH,  .triii  foriM  o^  t;til  ;  iluriii/  sutniru'r  thi^ 
.iiiini.'il  (live-^  for  and  proy*  on  fisfi,  l»iil  (liiriiiir  the  Umg 
w'litcr  it  leaves  th»*  fro/iMi  w.-iti'M,  .inil  nrt'vx  like  (»fhor 

IM(l(»-c;itM  on  tiiitH  and  l.ui-l  nnlrnti-.  If  a  (iitfi'rent  r.xs»« 
i.nl  iM't'ii  tiketi.  ami  it  ]\:ui  h»MMi  :i«k«Ml  how  an  imej'ti 
vontus  <|ii;niriij»«M|  could  po«ihlv  h.iv»»  hi'cri  convj'rted 
into  ;i  tiyiiii;  hat,  the  i|ii««stion  would  ha\(>  hpcn  far 
riiori'  ditfii  lilt,  and  I  could  have  ;:i\i'n  no  aii^wpr.  V»it 
I  think  such  difhculties  h.ivo  very  little  wfiaht. 

Hero,  ax  on  other  o<  <  a'^iotH,  I  lie  under  a  heavy  dis- 
ad\ant-ii:»>,  («»r  out  of  tho  many  strikiiijf  ia>es  which  1 
have  collected,  |  can  ifive  only  one  or  two  i'l^t.-ince^^ 
of  transitional  liaMt><  and  structures  in  chwelv  allie«l 
specie-*  of  the  -ame  yen  us  ;  and  of  diversified  habits, 
either  consfuif  ctr  occasional,  in  the  same  species.  And 
it  cems  to  trie  that  rn»thint'  h"*"*  than  a  loin;  list  of  such 
cases  is  suflicient  ti»  lessen  the  diMii  ulty  in  any  par- 
ticular «'ase  like  that  of  the  hat. 

L>ok  at  the  family  of  sijiiirrels  ;  here  we  have  the 
tine-t  eridation  from  animals  with  their  tails  only 
slightly  flattened,  and  from  others,  as  Sir  .'.  Kichanlson 
iias  remarkeil,  with  the  posterior  part  of  their  Utdies 
rather  wide  and  with  the  skin  on  their  tianks  ratlier 
full,  to  the  >;o-caIled  tlyinjr  sijuirreU  ;  p.nd  lUinjf 
squirnds  have  their  limhs  and  even  the  iia.-e  ef  the  tail 
united  hy  a  hroad  expanse  of  skin,  which  serves  a.s  a 
parachute  and  allows  them  to  jrlide  throujrh  the  air  to 
an  astonishiiiir  distance  from  tree  to  tree.  We  cannot 
douiit  that  each  structure  is  of  use  to  e.ich  kind  of 
sijiiirrel  in  its  own  country,  hy  enahliiiL'  it  to  esca})« 
iiirds  or  heats  of  prey,  or  tocoilei't  toinl  more  <|uicklv, 
or,  art  there  is  reisori  to  helieve,  hy  lesseninir  the 
dani^er  fr<«in  occasional  falls.  IJut  it  does  not  f<d!ow 
from  this  fact  that  the  structure  of  each  stjuirrel  is  the 
hest  that  it  is  possible  to  conceive  under  all  natural 
condition.s.  Let  the  climate  and  veiretation  chanjfe, 
iel  other  competitu;  rodenUs  or  new  tveasts  of  prey 
imrrugrate,  or  old  ones  become  modified,  and  all 
aualofry  ^ould  lead   us  to  ttelieve  that  some  at  lea:>t  ol 


I)IFKF(  f  I.TIKS   ON    IMKOKY 


i«;;» 


i 


thi'  -.iniirri'l"*  wniilii  (ii'irea***  in  minilnTii  or  iMToriii* 
»' vt»>rtiiiii.it«<<l,  uii!f-.>4  tln'v  al-»)  lu'raim*  nunlitu"il  .. kI 
m;|iri»\««i|  in  «trin  tiir»»  iii  .»  rorri'^tpoiuliri^  tnniiiicr. 
riiirefnre,  I  iviii  •>♦•<•  nn  iliflii  iilly,  more  e«|>«'ti;illv 
ninl«'r  i'lir»n;:iiiLr  '  umlitioiia  of  lifp,  in  flip  fiMitimn-'l 
|>'-i-<Tv;iti<in  of  inrliviii'ials  witli  IuIUt  and  fiiII«T  llank- 
'luTiilir.'iii*'-,  i-arh  modification  hoin^  iixpfiil,  rarh  lipint' 
jtrnpac'i''''.  until  l-y  th»»  arcnmiilativl  ♦•rffct^  of  thu 
|iriMt'«i-  of  natural  >rl»'rti()ii,  a  jM-rfett  i*(>-rallt'd  flyin;j 
Htj'iirrfl  ".■i>  prfxluiod. 

Now  look  at  the  (JaU'ojtithecim  or  thin:,'  lemur, 
*h'ili  fortrifrly  w.t«  faUoly  ranked  atnonirst  }iat>.  If 
li.iH  an  exfrt'ini'ly  wide  flank -rnfmhrane,  strotcliinj^ 
fr(ir?\  tlie  forner"*  ot  tlio  Jaw  to  tlie  ta:l,  and  including 
the  IifmIh  atid  tlie  eli-iiL'^ted  fintrers  :  the  flank-nieni- 
hriim  ;•*,  also,  f'urnisheii  witli  an  extensor  niiiscle 
AltlioiiL'h  ii't  ;,'radiiatod  links  of  .structure,  fitted  for 
u'lidinj:  fliroii;;li  the  air.  now  connect  the  («aleo[iitht'cu« 
«ith  th"  other  I.cinuriila*,  yet  i  see  no  dill'Multv  in 
sii;«|i(i>;nu'  tli.it  mull  links  formerly  exiftted,  and  that 
eaili  had  '■•■.■n  formed  hy  the  s.-inie  -tejH  as  in  the  case 
of  rlio  !'■-'  |ifrtV(  tly  trliijintr  s«ji;irrels  ;  aiul  th  ii  each 
trrade  of  strurture  uas  useful  to  its  jios>essor.  Nor 
can  1  see  an?  ifisujicrahle  ciifliculty  in  further  l)e!ievinL' 
if  possible  that  tiie  meinlirane-connected  fin^er.-i  and 
tore -arm  of  the  ( ialconilhecus  mitrht  he  jfreally 
leii.:tht'ned  hy  nafiiral  selection;  and  this,  as  far  a^ 
the  (iriTaiirt  of  flij.'^ht  are  concerned,  wouM  convert  it 
into  a  l>at.  In  hats  which  have  the  win^r.niernhrane 
extended  from  tlie  top  of  the  shoulder  to  the  till, 
incliidirifr  the  hind-le;rs,  we  perhaps  see  trai-es  of  an 
apjiaratus  oriLritially  cot.»tructed  for  plidiiur  throuch 
tie  air  rather  than  for  fii;:ht. 

If  ah«Mjt  a  do/eu  ^renera  of  hirds  had  hecome  extinct 
or  were  unknctwn,  who  wouM  have  ventured  to  have 
surmised  that  hirds  mitrht  have  existed  which  u>eil 
their  winir«  solely  :ih  'l.-ipiter^,  like  the  lr-=r-;?r-h?'ridei' 
du.k  (Micropterus  of  Kyton)  ;  as  tins  in  the  water  and 
front  le^  on  the  land,  like  the  j^eny-uin  ;  as  sails,  lik 


the  outrirh  ;  and  functionally  for 


no  purpo>-e,  like  the 


i«;4 


ON   IHK    OKKilN    OF   SPECIES 


m 


Aptpryx.  \iA  tlie  structure  of  cacli  of  these  Itirds  is 
trooil  f(»r  it,  uiidor  tlin  c(»iiilitioii!>  of  life  to  which  it 
is  exposrcl,  for  i;;i(h  li.is  t;>  live  by  a  •■truiririe  ;  hut  it  in 
lint  iifcr».;irily  the  i>e-l  jtio-ihle  u!n!"r  all  piw-ihle  con- 
diHoii^.  It  must  not  \,k  inferred  from  tlit'>»'  reni.irks 
thiit  any  of  tiie  tjr.i<l('s  of  win;::-structiire  hero  alhided 
t(».  wli;i  li  perhaps  riia\  ail  have  rt'-iiited  from  disuse, 
iiidnaii-  the  ii.iliiral  steps  iiv  w  hich  l)irds  have  aeijuired 
tiieir  perfect  jiower  nf  lii::lit  ;  hut  thev  serve,  ;it 
lea^t,  to  show  what  di\  er>iti('(i  riieaiis  of  traii>itiun  are 
I n.h-. 

>eeiii:r  that  a  leA-  nienihers  of  such  water-l'reainiii^ 
cl.i-se->  as  the  (  rusttcea  aini  Mollu-ca  are  adapted  to 
live  oil  the  laii  1  ;  and  seeing  that  we  lia\e  flyinir  hirdu 
and  iiiaiiiriiaU.  liyiii;^  injects  of  tlie  most  diversiiied 
t\|'ev.  .iiiii  foriiierlv  had  tlyiiiir  reptiles,  it  i^  con- 
ceiv.ihle  tliat  llyii:_  n>h,  which  now  trlido  far  tiirMii;:h 
the  air,  sii^ihtly  n-iiir  and  turnini:  l»y  tlie  aiil  of  tiieir 
flutteriui:  li'i-;,  ini:,''J  hav.-  Keen  iiHidi;ifd  into  perfectly 
'»in:red  animals.  It  this  lia<i  tweii  ejfected,  who  would 
iiave  e\iT  ima^^incd  that  in  an  early  iraiisifiniial  stiite 
'!ie\  liad  ln'cn  ii:liatiitaiits  of  the  oj)t'ii  ocean,  and 
h  id  u-ed  their  incipriit  or^'ans  of  ihirhl  e\^lu-i\eh-,  as 
:ar  as  we  know,  to  I'srape  l)einL''  devnured  hy  uther 
t,-]i- 

W  hen  we  «ec  any  structure  hitrhly  pejtected  for  anv 
particuhtr  hahit,  jis  the  winjrs  of  a  hud  tor  llitrht,  we 
shoulij  dear  in  mind  tliif  animals  disidayiiitf  early 
t  raiisitional  trrades  ot"  the  -tructure  will  st-ldnm  continue 
!•■  e\wt  to  the  prevtMit  day,  for  they  will  !ta\e  heen 
supplanted  hy  the  \er\  process  of  perfection  throutrh 
natur;il  -eloctiori.  |-"urthermore,  we  may  comlude  that 
transitional  L'r.ide-  'leiwcen  structures  titted  for  verv 
different  iialn's  of  lil'e  will  rarelv  lii\e  h«'en  deselopeii 
ai  an  e^irly  period  in  i^reat  nunil>er>  and  under  main 
suhordinatt'  !orm-.  Thus,  to  return  to  '•  ir  imairitiary 
illustratiiui  of  the  tlyintr-tish,  it  does  not  seem  pridalile 

t       li     li^'^e-.     ctji.iiii*'     oi      Iruo     ii:;^ilL     Hiiiiid      iiave     iu'eu 

d"\e.(ij..  i  uruicr  many  siilMirdinate  turiii*,  for  takiny 
prey  uf    niany  inids  m  many  ways.  r)ii   the  lam!    and    in 


DIFFK  ri/riKS  f)N  •mE( 


tr>5 


t\.(^  water,  until  tiif'ir  orc"aii«  of  flight  i  .  -ome  to  a 
li  .:li  staire  of  {K-rfeetioii.  so  as  to  have  ffi.  ii  tlioin  n 
(l«'t  iui.^!  :i<iv;intaL''t'  over  ntlior  animals  in  tin'  l>attle  of 
lilt".  ll«Mi(e  th«'  clianre  of  (li-toveriiitr  sjk'cIi's  with 
transitional  irradi's  of  Htrtn-turo  in  a  fossil  oomlition 
will  ,ilvva\<  Iw  less,  from  their  havinir  existed  in  lev>.pr 
uiimKtTs.  than  in  tho  ('ase  of  pjM'cies  with  fully  ileM'loj»c<i 
-tr'ictiirfs. 

1  «ill  now  ;.rivi'  t'.vo  or  ihrvP  in-tani-e**  of  (ii\»'rsifnMi 
and  of  ch.iiiv'^t'd  hallit^  in  the  individuals  of  the  same 
specie-  W  hen  either  case  occurs,  it  would  i>e  ea«y  for 
natural  selecti<Mi  to  fit  the  animal,  by  ~ome  tiioditication 
of  its  >tructure,  for  its  «hanired  hal'i;-,  or  exclusively 
tor  one  of  its  several  different  hahit-.  Mut  it  is  difficult 
to  tell,  and  immaterial  tor  u<,  whetiu-r  habit'*  frenerall, 
chaiiL'e  first  and  structure  afterwards  ;  or  wlH'thcr 
^liffiit  ifuxlitications  of  structure  lead  to  chantred  liahit^; 
both  [>rohaMy  otleii  chanije  almost  simultaneously. 
«  "r  cases  of  clian^ed  haltits  it  will  suffice  merely  to 
iliude  to  that  of  the  many  Hriti-h  insects  which  now 
tVed  (in  exotic  plants,  or  exclusively  on  artinci.il 
suhstTiiceH.  ()f  diversified  habits  imiumerahle  instances 
cnuhl  he  g-iven  :  I  have  often  watched  a  tyrant  fly- 
catcher i  Saurojihairus  sulphuratus)  in  South  America, 
hovering  over  one  spot  and  then  proceeding  to  another, 
like  a  kestrel,  and  at  other  times  slandinj;  stationary 
on  the  mar^^in  of  water,  and  then  dashinti'  like  a  kmjf- 
tisher  at  a  tish.  In  our  own  country  the  larirer 
tittuouse  (I'arus  major)  may  he  seen  climbing'  branches, 
almost  like  a  creeper  ;  it  often,  like  a  shrike,  kills  small 
lijrds  bv  hlf»ws  on  the  head  ,  and  I  h;t\e  tnan\  times 
-.t"*-!!  anil  heard  it  hammerinff  the  seeds  of  the  yew  on 
»  Itr.im  h,  and  thus  hreakiinr  them  like  a  nuthaUh. 
hi  North  America  the  black  bear  was  seen  bv  lieariie 
sw  nimifi^'  for  hours  ..ith  wiilely  «ipen  mouth,  thus 
i-a'chmtr,  almost  like  a  whale,  insects  in  tlie  water. 

.\.s  we  son'etimes  see  indiviilual.s  of  a  sj.ecies  follow  ini; 
ha'iits  wideiy  tiiiiereut  irom  those  oi  liieir  own  sperie- 
anil  of  the  other  spi-cies  of  the  same  penus.  we  mi^ht 
expect,   on    mv    Mieory,   that    "^uch    individual?    wciuid 


166 


ON   THK    ORKJIN   OF   SPECIKS 


W 


oc«asionally  liave  jfiven  rise  to  now  KjHjcie*,  haviiij{ 
anonialotJH  }i;i!tits,  and  witli  tbcir  structure  either 
slifflitly  or  considerably  in(Mlifie<I  from  that  of  tlu'ir 
proj»«>r  type.  And  such  instanien  do  occur  iu  nature. 
-an  a  niore  strikinjr  insLince  of  adaptation  l»e  trivon 
than  that  of  a  woodpecker  for  dinihinj^  trees  and  tor 
•^ciziiifj  inserts  in  the  chinks  of  the  Iwrk  r  \ei  ni  .North 
.America  tliere  are  wtwidpcckers  which  feed  laruely  on 
fruit,  and  others  with  eiorifated  win^-s  whidi  cfia«.e 
iiiM'cts  on  tlie.  wintr  ;  anil  on  the  plains  o!  1^  I'lafi, 
whi-ienot  a  tree  throws,  tliere  is  a  woudfiecker,  whi.h 
III  every  essential  part  of  ilH  orpanisiition,  even  in  it,; 
ruloiirin^r,  in  tiie  har.sh  tone  of  \U  voice,  and  unduiatorv 
lii^'hl,  t(dil  nie  plainly  of  its  close  blood-relatioiiship 
to  oiirnimriion  speci.'s  ;  yet  it  i-  a  woo«lpc(k»T  which 
ficvc  ciimix.  a  t.ree  ' 

J'rtreis  ar.-  '.he  ino>t  aerial  and  t)ceanic  ot  inni-,  vet 
in  tlie  .|uiel  Sounds  of 'I'ierra  del  I'r  >^o,  the  INidinuria 
l.er.irdi,  in  its  peneral  habit,s,  in  its  a.stonishi  ^  po«cr 
<.t  diviiifr,  its  ni.iii  .■>•  of  rtwimminr,  and  of  liyuifr  w  lien 
uiiwillinjfly  it  Ukt.^  <l:j;ht,  would  he  mistak'en  l.y  any 
one  fur  an  auk  or  irrehe  ;   nevertheless,  it  is  essen'tiaiiy 

•  jietrel,  hiil  with  many  parts  of  its  ortfanisatiou  pru- 
loundiy    modified.       » )n   the    other    hami.    the    acutest 

■  '•server  l.y  examining:  the  dead  liody  of  the  water-ou/el 

•  Mild  never  have  susi)ected  its  «uh-aquatic  iiahits  ;  yet 

ihis  anomalous  member  of  the  strictly  terrestrial  thni-h 

'aniily  wholly  subsists  by  divin^r^—pVaspine  llie  stones 

with  its  feet  and  usin;j  its  wintjs  under  na'i  r. 

fie  who  believes  that  each  beiuic  has  Wen  created  as 
we   now    see   it,    must   occasionally   ha\e   feit   surprise 

•  •hen  ho  ha.s  met  with  an  anunal  haviiii;  iial»itj»  and 
structure  not  at  all  in  .i^reement.  \\"ti:a  can  be 
p'  iinor  than  that,  the  webbed  feet  ot  duck-  and  eee^e 
ure  formed  for  sw  miminff  .-■  yet  tliere  are  upland  ^ei'-,e 
»'.  itii  welilted  feet  which  rarely  (sr  never  po  ne;ir  the 
^'■ater;    and    no    one    excejit    Audubon    has    seen    the 

us  lour   itM'S  nciMieii,  Miij^iii 


a.s  ait 


»■_;,...»,,  1  :„  1      ,,  I 

on  the  surface  of  the  sea.      On  the  other   hand   kJcIk'h 
and   cent  .  are  eminently  aipiatic.  altliMU^rl,    their   toe» 


r^SH^isai 


DIFFICULTIES   ON   THKOKV 


167 


are  only  Jwrderod  h\  nu-mlmme.  U'liat  Kt-enis  plainer 
than  that  the  li.nir  toes  ot  ^r«llatores  are  Jornied  for 
v»alk;nsf  over  swamps  and  lloatinir  plants,  yet  the 
water-hen  i<  nearly  bh  aijiiatie  a:-  the  ««»nt ;  and  tlie 
landrail  nearly  as  terrestrial  as  the  (jiiail  or  ji.ii tridtre. 
In  Biicb  cH-es.  anil  n>any  other-  .oiild  l>e  tfi\en,  hahilM 
have  cliaiif:e<l  without  a  correspond ititi  chancre  <'f 
strurture.  The  wehl-ed  feet  of  the  upiand  jfoose  may 
he  (iaid  to  have  l»ecome  rndiinenlary  in  function, 
ihouL'h  not  in  Htrurture.  In  the  friirate-hird,  the 
1»  deeply-stooped  nienihrane  hetween  the  toe«*  shows  that 
structure  h.is  l.ctrun  to  chanu'^e. 

lie  wlio  Itelieves  iu  separate  and  innunierahlc  acts  of 
cre.-itK.n  will  say,  that  in  the-e  cases  it  has  picked  the 
Creator  to  «ause  a  hein^  of  one  type  to  take  tlie  place 
o'"  one  of  another  type;  hut  this  seems  to  me  only 
re-statititr  the  t:ict  in  difrnified  lant;ii.i{re.  He  wlio 
helieves  m  the  -tru;rtrle  f.»r  existence  and  in  tlie 
principle  of  r.atijral  selection,  will  acknowledge  that 
everv  oriranic  heinj;  is  (onstaiitly  endea\ounn:r  to 
increase  in  numhers  ;  and  that  if  any  one  heinjr  vary 
e\er  so  little,  either  in  liahits  or  structure,  and  thus 
eain  an  advantage  over  some  other  inhahitant  of  llie 
c<»untry,  it  will  sei/.e  on  the  place  of  that  inhahitant. 
however  diiterent  it  may  l)e  from  its  own  place.  Hence 
it  will  cau>e  him  uo  surprise  that  there  should  he 
^ree^•o  and  frijfate-birds  with  wehU'd  feet,  liviji;;  o-i  the 
dry  land  or  most  ra:fiy  alitjhtintr  on  the  water  ;  that 
there  should  be  lontc-tood  corncrakes  li\  injf  in  mead(»ws 
inste-ad  of  in  swantps;  that  tiiero  should  h«-  wood- 
jK-ckers  where  not  a  tree  t'rows  ;  tliat  there  should  he 
divinp  thrushes,  and  petrels  with  the  hahits  of  auks. 

Orgtius  ot  extreme  pfrjWtwn  ana  contpliaition.  —  'lo 
suppose  that  the  eye,  with  all  its  illimitable  contriv- 
ances for  adjustintr  the  focus  to  ditTereiit  distan<es,  lor 
adTnittmu  different  amount;  of  light,  and  for  the 
coiieilioii  or  pptifruai  and  <-i:ru!::a.2:  a.:-e.ia-.iOU,  t •><.;«, 
have  i>een  formed  hy  natural  selection,  seems,  I  freely 
confesv.  absurd  in  the  h'.jfhest  possible  decree.       Vf. 


168 


ON   THK    OKKilN    OF   M'K(  IF> 


I 


r&'ison  tells  rne,  tli.it  if  iiurntTnii-i  LTad.-itiotis  Irorn  a 
porfoct  and  complex  eye  to  one  \v:y  iin|M'rt»'.  t  ami 
siniplo,  each  (irailo  ln'iiit'  ii'^i'tul  to  it-,  pi !*>»•->.(, r,  can 
!)♦•  slinwrj  to  c\i>t  ;  if  furtii.T.  tin-  ey«>  Huck  vary 
v\OT  SO  slitrlitly,  and  tli.-  variatmiis  I-m  inlieritcti', 
nhich  is  certainly  tlic  i  i>c  ;  and  if  anv  \ariation  or 
nmdifjcation  in  the  or;:an  'i>e  evt'r  ii'.etui  to  an  anim.'.l 
under  cliaiiL'-iiiir  <'oniliti(.ns  nf  lite,  tlicn  ti.e  diilicnltv 
of  helievintr  that  a  i»er!ect  and  corii|)lex  e\e  could  bo 
tornied  \>y  natural  selection,  thoiiL'ii  in-.u|ierahle  by 
our  iriiariii'ition,  can  hardlv  lie  con-u'ered  real.  How 
a  ner\e  cunies  to  he  -en»iti\e  to  li;:ht,  hanllv  cuncerns 
tjs  riior(!  than  how  life  itstdf  tirst  ori;,'-inated  ;  h>ut  I  may 
remark  that  s»'vcral  facts  mai<e  mc  suspect  that  any 
sensiti\e  nerve  may  he  rendered  sensitive  to  lij-ht,  and 
likewise  to  those  coar-er  vihratioim  of  the  air  u!:;ch 
proiluce  sound. 

In  hinkirii,'  for  tlie  ^rradatioris  hy  whi-li  an  oriran  in 
any  sjieciis  has  heen  perfected,  we  oiiji-ht  to  look 
e.\.lii>ively  to  its  lineal  ancestors;  l»ut  this  is  -carcely 
e\er  possible,  and  we  are  forceil  in  each  <ase  to  look  to 
species  of  the  K.aino  frniup,  that  is  to  the  collateral 
'iescendants  from  the  same  oriLMnal  narent-f(»rTn,  in 
order  to  see  what  t:radations  are  possilile,  and  for  the 
<  hance  of  some  trradations  lia\in<f  heen  transmitted 
tioiii  the  earlier  staires  of  descent,  in  an  unalfer«'d  or 
little  .litered  condition.  AmonL^>t  e-xistiriir  \'ert»'hrata, 
we  find  hut  a  small  amount  of  ;,'-radation  in  the 
stru(  tiire  of  the  eye.  and  tr(»m  fossil  species  we  can 
Ifarn  nothini.'-  on  tin-  iieail.  In  this  ^-^re.it  cla.s.s  w© 
should  pnd.ahly  have  to  descend  far  heneath  the 
li'west  known  fo-sihleroiis  stratum  to  discover  the 
•  .iflicr  staire-.  hv  which    he  eye  has  heen  perf.  cted 

!n  the  ArticuiatA  we  can  commence  a  series  with  an 
optic  nerve  merely  coated  with  pi^rment,  and  without 
any  other  mechani.cm  ;  and  Irom  this  lnw  staire, 
nnmerous  trradations  of  striiciure,  iiranciniitr  otf  in  two 

....        I .     »         I   1  ..  1       .1-  .        !•  _         .  I 

:-.i;. •:.:;:;;::;-;;  ;y    ;;;;;crc:;i    iinCS,    i.'iu     iiC    Siiurt  u    In    e.visL. 

unL.l  we  reach  a  in»>derately  hi^jh  stiijre  of  perfcctiua. 
In  .ertain  crustaceans,  fur  instance,  there  is  a  double 


m .' ' 


3^- 


DIKFiri'LTlKS   ON    rHEORY 


lfi!» 


roriK'n  the  inner  one  diviileil  into  fa»\ts,  within  earh 
of  which  there  is  a  leim-«haj»etl  f!w»-iliinf.  lit  otlier 
crustareans  t'lc  tran«i'.irent  «  oiiex  whi<  li  are  rf>,ae<l  l>y 
T)!:.Mii«'iit,  iiiii:  »hif)i  projierly  ;i(t  onlv  by  exilmiini; 
Literal  p«'ririU  of'hirht,  are  convex  at  their  ii[>|M'r  euii* 
and  must  act  tiv  ((invprt^crice  ;  ami  at  tlieir  hmer  •  :iiir4 
there  seems  to  he  an  irnperfecf  vit  .ous  suhstauce. 
^^  ilh  these  fails,  here  far  to«.  hrietly  aiui  inijn  feitlv 
triven,  wliich  -^liow  that  th^re  is  much  i:raiiuate<i  iii\er 
sity  in  tJie  eyes  of  liviiiir  irustareaiiH,  ami  hearing'  ni 
niind  h«>vf  small  the  niiinher  of  Irintf  a'lirnals  is  si; 
pro{>nrt:on  to  those  which  have  heconi*'  ex  .net,  I  ••an 
see  no  \»*r\  trrt-at  difTicultv  (not  more  '  an  in  the  case 
of  many  other  stnirture't  in  helievinar  that  n..  iira 
seieciion  lias  converted  th««  <  pie  app.fatus  of  an 
optic  nerve  merely  coated  with  j  lament  and  invested 
h\  transparent  menihrane,  into  an  op  'al  instrument 
a-  perfect  a-  in  pos!>es»ed  by  any  menil)er  of  the  jfreat 
Articulate  ilass. 

lie  who  will  tfo  thus  far,  if  he  '"nd  on  tinisliin-r  thi"* 
treatise  that  larire  bodies  of  fact.-,  otlierwise  inexplic- 
atile,  can  he  explained  by  the  theory  of  descent,  ought 
not  to  hesitate  to  go  further,  and  to  admit  that  a 
structure  even  as  perfect  as  the  eye  of  an  eaule  niitrht 
Ite  forme<l  hy  natural  selection,  although  in  this  caso 
lit?  does  not  know  any  of  tin-  transitional  tfrades.  His 
reason  ouirht  to  cornjiier  his  nia;rii»ation  ;  thou>;h  I 
have  felt  the  difficulty  far  too  keenly  to  i»e  su'-]irised 
at  any  detrree  of  hesitation  in  extendinir  the  pnu'-iplp 
of  natural  selection  to  such  st.irtlinu  leiiifthH. 

It  is  --carcelv  possible  U)  aM'id  comparing  th»»  eye  to 
a  telescope.  We  km-w  that  this  instrument  h.i>  l)een 
perfeited  by  the  lontr-eontirnied  etforta  of  ih<*  liijfhest 
M.iman  intelleets  ;  and  we  naturallv  infer  that  tlie  eye 
has  been  funned  by  a  somewhat  analogous  process. 
5'"Ut  may  n«it  this  inference  J>e  presumptuous.^  Have 
«  '  any  riirht  to  assume  tliat  tfie  (  reator  works  by 
1  uTr-iiect (i<ii    ponrei!*    iiKe    Uio^e    oi     man.'      il    nt*    iimst 

compare  the  eye  to  an  optical  instrument,  we  oLirtit  iu 
in\at;ihatii>n  to  tal^e  a  thick  layer  of  tran.sparent  tissue, 


5f^ 


^.ici^. 


170 


ON   THK   ORK.LN    OK  SPECIES 


11 


•AJth  a  nerve  ueiiKitivc  to  lijfht  Ix-utath,  and  then  8uj»- 
p<)sp  every  part  of  thi>  layer  to  bo  continually  chanjriiig 
nlovvly  in  density,  so  as  to  Keparate  into  layern  of  diricr- 
eiit  densitit--  and  thicknesses,  nl.iced  at  dilfcrent  «lis- 
tanccH  from  each  other,  and  with  tlie  surfaces  of  each 
lajer  slowly  chantrintr  in  luriii.  Further  we  must  sup- 
pose tliat  there  is  a  power  always  intently  watching 
each  sli;,'ht  accidental  alteration  in  the  iransj^rcnt 
layers;  and  carefully  -cU'ctinp:  ea»Oi  albTation  wiii.h. 
under  vancd  circumsLince^.  may  in  anv  ^ay,  or  in  anv 
df;rre«',  tend  to  produce  a  distincter  irii,';;e.  \\  v  mu.-t 
Huptio-.'  each  new  stite  of  the  instrument  to  h*' 
inultiphcd  hy  the  million;  and  each  to  lie  prc^-erved 
till  a  Ijt  tier  he  produced,  and  then  the  old  unes  to  he 
d»ixtr.(yed.  In  livinjf  hodies,  variation  u.'l  cause  the 
sligiit  alterations,  peueralion  will  inullijdy  tliem  almost 
intiintely,  and  natural  selection  will  pick  out  with 
unerrin-;  skill  each  improvement.  U-t  this  j)r()ces>  uo 
on  lor  millions  on  millions  of  years;  and  during'  each 
year  or;  millirjiis  of  individuals  of  many  kinds;  and 
may  we  not  helieve  that  a  livijiff  optical  instruineiit 
m  ^lit  thus  ho  formed  as  superior  to  one  of  ::lass,  as  tliC 
works  ot  the  (  reator  are  to  those  of  man  r 

It  it  could  he  diinonstrated  that  any  comjdex  or^^-^an 
existed,  which  could  not  possibly  have  lifcn  formed  hy 
numerouij,  successive,  sli;rl,t  modifications,  my  theory 
would  al)s()lutely  break  down.  Hut  J  can  find  out  nii 
such  case.  No  doubt  many  organs  oxi.st  of  which  we 
do  not  know  the  transitional  gradeti,  more  especially  ii 
\se  look  to  much-i>olated  species,  round  which,  acct)rd- 
intr  to  my  tlu'ory,  there  has  been  much  extinction.  Or 
liiam,  if  we  look  to  an  orirau  common  to  all  'he  mem- 
•t-rs  of  a  large  class,  for  in  this  latter  ea.se  the  organ 
must  have  been  tirst  formed  at  an  extremelv  remote 
period,  since  which  all  the  many  members  of  the  cla-s 
h.i\e    heen    developed;    and   in   order   to   discover  tlie 

e.irly  transitional  gra.les  through  which   the  organ  has 
.„        I..  1,  —  111  .     1     1. 

J  .1  .,  n;    ^.:uliiu   iitl>U  lU  iOOK   tO  '»erj  uiiiiCiiL  iiin  e^llui 

tornis,  loii^  since  become  extinct. 

^^  e  should  be  extremely  cautious  in  condudinif  that 


hi 


DIFFICULTIF-S   ( )N   THEOIIV 


171 


■la  orpaii  could  not  have  bet'ii  formed  liy  transitiotiai 
grad.itioua  of  Kome  kind.  Numerous  ca'<i^  could  l>e 
irivou  amoiiL'^'t  tlio  lower  animals  of  the  same  or(;.tii 
performintr  at  the  Kaine  time  wholly  distinrt  fun«"tions  ; 
thus  th<'  alimentary  canal  respircH,  digests,  and  excret**** 
in  the  larva  of  the  dragon-fly  and  in  the  lish  Cohite-.. 
In  till'  Hydra,  the  animal  may  he  turned  inside  out, 
and  the  exterior  purface  will  then  dni^est  and  tiio 
Htoriia*  h  rt'-jtire.  lu  such  cast-s  natural  eflection  niii»-ht 
e<4sil\  specialise,  if  any  advantage  were  thus  ^--aiind,  a 
part  or  oriran,  which  had  performeil  two  function-,  lor 
one  function  alone,  and  thus  wholly  chanjje  its  natu!»« 
hy  iii-ensihle  stt'ps.  Two  distinct  ortrans  gometim*'-* 
perform  simultaneously  the  same  function  iu  tlic  sari..! 
individual  ;  to  tive  one  instance,  there  are  fish  with 
jills  or  hranchi*  that  hreathe  the  air  dissolved  iu  tlie 
water,  at  the  sarue  time  that  they  hreatho  free  air  iu 
:heir  swimhUdders,  this  latter  or^^n  liavin^  a  durtus 
pMcuniaticus  for  its  Bupply,  and  hein^  divided  hy  highly 
vast  ular  partitions.  In  these  ca-es  one  of  the  two 
or(^aiis  mifi^ht  with  ease  he  modified  and  perfected  so  as 
to  perform  all  the  work  hy  itself,  heing  aided  durnur 
tlie  procft's  of  modification  by  tin*  other  or^au  ;  and 
then  this  other  or^ran  mijfht  l*ti  mo<lified  for  some  othtr 
and  (juite  <li-tinct  purpose,  or  1k3  unite  obliterated. 

Ilie  illustration  of  the  swimbladder  iu  fishes  is  ,» 
^ood  one,  In^cause  it  shows  us  clearly  the  hitrhiv 
important  fact  that  an  orfjan  orijfinaily  con.-trui-ted  for 
one  purpose,  namely  flotation,  may  Ihj  converted  into 
one  for  a  wholly  different  purjK)se,  namely  respiration 
'Hie  swimbladder  has,  also,  been  worked  in  a-s  &ii 
accis>;ory  to  the  auditory  org^ans  of  certain  f'sh,  or,  for 
1  do  not  know  which  view  m  now  ^enera'ly  held,  a 
part  of  the  auditory  apparatus  has  been  worke<l  in  as  a 
complement  to  the  swimidadder.  All  ph\  siolo^^ist- 
admit  that  the  sw  imhladder  is  hcinoloyous,  or  *  ideally 
eimihir'  in  position  and  structure  with  the  luric>* 
ot  the  higlier  vertebrate  annuals  :  heiue  tliero 
st'cms  to  me  to  be  no  frreat  ditTu  ulty  iu  beLe' - 
ing   that    natural   selection   has  actually    convertei!    a 


■ 


172 


ON   THK   OKKJIN    OF   SPK(  IE8 


BwiTTiMadder  iritu  a  luri^,  or  ortraii  n^»  .1  oxclusively  for 
r«•^jli^.'ltioll. 

1  ran,  iiidppd,  liirdly  doiifit  that  all  vortrf.rate 
animals  h.Hv;ii;r  trim  liiriir'^  liave  dr^^cciidcd  l>y  oniiii.iry 
fi'iifratitin  from  an  anrieiit  protntypo,  of  wlii<  li  we 
kimw  nntliiiiir,  fiiriiislu'd  nitli  a  tlo.itiiiir  af)|>ar-itiis  or 
■.wirnlilaildcr.  \\'»»  cin  \h\i<.  an  I  infer  ;r<>m  I'rdfevsor 
Ov»fu  H  ir.tfrostin:;  di'scription  (»f  tlie-o  parts,  iinder- 
Ktiind  the  >«trai!u'e  fart  tliat  every  particle  of  fofxi  and 
drink  which  we  '•waUow  has  to  p.i>,-s  o\er  the  i<ritice 
of  t!ie  trache.i,  with  .■>onie  ri-k  of  fallintr  into  the  I'li^'s, 
Motvntlivt  iiidni^'  the  hea;itifiil  roiitrivanre  \>\  which 
the  trl'iilis  is  clcised.  In  tlie  hitrher  \'ertel.rata  the 
'iraiK  hiii"    have   wholly    ilisa|)p»'ared      the    slif.a   on    the 

wi.-*  of  t)u«  neck  and  the  loop  like  course  of  the 
arteries  -till  markini:  in  the  enihryo  their  former  posi- 
tion. I'.ut  it  is  coiicei\aMe  that  the  now  utterly  lost 
hranch  .H  mijrht  have  lieen  trradually  worked  in  hy 
•satiirai  sdec  tiori  for  some  quite  distitict  purpose  :  \n 
•he  <itiie  manner  as,  on  the  view  entertained  hy  some 
i:aturalisLs  that  the  hranchiie  and  dorsal  scales  of  Anne- 
l.ds  are  homolotrous  with  the  winp*  and  win^-covers  of 
inse<ts,  it  is  prohahle  th.it  organs  which  at  a  ■. ery 
aM.ient  period  served  for  n-piration  have  heen  actually 
converted  into  ortrans  of  flitrht 

!n  consideriiifr  transition-s  of  orp-ans,  it  is  -o  imjiortimt 

'  iie^ir  in  mind  tlie  {irohahility  of  coiuersion  from  one 
tiinclion  to  another,  that  I  Mill  ^rive  one  more  instance, 
redui.cuhited  ciirijierles  have  two  minute  folds  of  skin, 
•  ailed  hy  me  the  ovJi^erous  frena,  which  serve,  through 
the  means  of  a  sti(  ky  secretion,  to  retain  the  etrtrs  until 
•he;,  are  h.itt  hi'd  within  tlie  sack,  'ihose  (impedes 
ii.ne  no  hraiit  ).iji»,  the  whole  surface  of  the  houy  and 
sack,  iiicludinif  the  small  frena,  serv in jr  for  respiration. 
Die  I'.aianida'  or  sessile  cirrijiedes,  on  the  other  hand. 
In  •'  no  o\iirt'rt»us  frena,  t};e  efrtr*  lyinsr  loose  at  the 
h,)ttoin  of  the  sack,  in  the  well  enclosed  shell:  hut 
wiii  y  .  .r.  ,■  i,,r  :€■  loMleii  oiainiii*t«.  iVow  i  Liiiiik  no  one 
will  di-jiute  that  the  ovi^-erous  frena  in  the  one  family 
^r«  struily  hoUHilo^rou;!  with  the  hrauchm"  of  the  other 


DIFFlCUi;;ih>   ON   THKoKY 


17a 


f.imilv  ;  imlfvil.  tlu'v  ♦rnulii.ite  ititofaili  nllifr.  Tlier**- 
lore  I  (!i)  nut  doultt  that  little  foliN  of  -kin,  «liicJi 
oritrinallv  '*»'r\e»l  as  ovict'rou-*  frt'n.i,  l»iit  which,  like- 
wii4«»,  verv  >li;:htly  ai(l«vl  tin*  ;ict  of  rt'spinition,  have 
\<t^'n  iir:id\i:i\ly  convfrttul  l»y  n.ilural  ^^'i»•«  lion  into 
hrH!ir>  lit*,  sHiiiily  tlirou^rh  an  increase  in  their  si/e  atut 
the  iiKKteratidii  of  tlu'ir  aiUiesive  fjiainU.  It  :ili  peii 
unculatt'd  cirri[)«Mifts  ha'i  t«ecome  extinct,  ami  tlie\ 
ha\e  already  suffered  lar  lunre  exlinction  than  lia\t» 
ses*i!e  cirrijiedes,  who  wduld  e\er  have  imairined  thai 
the  hraiHliiir  in  this  latter  family  liad  or!j;inally  existed 
as  ortrir;-;  (or  jireveiitiiijf  the  ova  from  lieiii;;  w.ixh<'<) 
out  (it  tlie  '•ark  r 

Althoiiirli  we  must  1)«  extremely  cautious  in  con- 
cliniiuL'  that  any  t»ri;an  could  liol  possihly  h.i.e  l^eii 
produced  by  successive  tran-ilioiial  irradations,  vet,  un- 
<ioul'tedly,  irrave  ca.>»es  of  difliculty  occur,  some  oi  which 
will  l>e  di<cu>sed  in  my  future  work. 

('lie  of  the  4rra\e^t  is  that  of  neuter  injects,  which 
are  ott»'n  \ery  differently  constnjcte<i  from  either  the 
mah's  or  fertile  females  ;  hut  this  case  will  \xf  treated 
of  in  the  next  chapter.  The  electric  or^'ans  of  fi-«hc» 
offer  another  case  of  <[)ecial  difficulty  ;  it  is  imp<»sililf 
to  conceive  hy  what  step-;  these  wondrous  or;rans  have 
hee:;  produiH'd  ;  hut,  a-  (  >v\fn  and  others  have  re- 
marked, their  intimate  .-tructure  closely  resemhies  that 
of  I'ommoii  nuKcle  ;  and  as  it  has  lately  In-en  shown 
that  Kays  have  an  or;ran  closely  analoic'uis  to  the 
electric  aj^paratu-,  and  yet  do  not,  as  Mattcucei  asserts, 
di  >cliHr«^e  any  eh  ctricity,  we  must  own  tiiat  we  are  far 
ti>ti  itrnoraiit  to  ar^ue  that  no  transition  of  any  kind  is 
piissihie. 

1  he  ele'tric  ort^ans  offer  another  and  cM-n  tiiore 
serious  diiliculty  ;  for  they  occur  in  only  about  a  do.-en 
(i^lifs,  of  which  ^e\eral  are  widely  remote  in  their 
affinities,  iienerally  when  tiie  s;ime  orjran  appear-  in 
several  memf)ers  of  the  -ame  class,  estH'cially  if  iu 
meiiihers  having  very  different  hahils  of  life,  we  may 
attriliute  its  iiresence  U>  iniieritance  from  a  tommon 
ancestor  ;  and  it^j  ah>ence  in  -oiiie  of  the  tnemhers  lo 


!     <s 


174 


ON    THK    OIIMJIV    OK   SI»^:(  IKS 


14 


its  l(Kn  tlimiiirli  ilisij"i»>  or  nrituml  ■itlccliori.  Mut  if  the 
olcctric  orff.uis  hud  Ihtii  intifritnl  from  ciiio  amit'nt 
prD^-i'riitor  thus  pnu  idfd,  we  niiirht  li.ive  cxii.-t  tt'd  that 
all  »'lt'i'tric  f"i-lM"s  Willi  III  lia\«<  heeii  spi'ri.iHv  r<'!at»'d  to 
iTicli  otlicr.  Nor  dnr-i  (.noloirv  at  .ill  liail  to  tli»'  lu'lief 
tiiat  toriMcrly  nio-t  li>lifs  h.id  fifi  trie  urt:iii>.  whirh 
nuwt  of  tlM-ir  irutdilu'd  df-n-iHlaiit-^  have  lo«f.  Hh' 
pri'S«'ii(i'  of  lumiiioiH  ortjaiM  in  a  fi-w  ir)«-('(t«<,  hflnnir. 
iiitf  to  ditfi'r»'nl  faniilifs  and  orders,  otTi-ri  a  [laralh-l 
ca-i-  of  ditlii  iilty.  <  UinT  rases  could  he  Lriveii;  for 
iiistaiico  in  iilaiit-^,  the  very  eurioiis  (•oiitri\  arne  of  a 
ma-*  of  ptdlcn-tTaitis,  honie  on  a  foot  stalk  with  a 
wtii  ky  irlaiid  at  tlie  end,  is  the  same  in  ( )i  ■  liis  and 
A'clfpias.  :^eiieiM almost  as  remote  as  possilde  atiioiit;>,t 
l^twerini:  plants.  In  all  these  cases  of  two  verv  distinet 
sperii's  furnislied  with  apparently  the  -ame  anomaioiis 
o;^ran.  it  shouM  he  oli-tTved  that,  althoutrh  tlie  ijeneral 
appearance  and  function  of  the  or^'an  mav  lie  the  same, 
yet  some  fundamental  ditference  can  trenerallv  he  de- 
tected. I  am  ificlined  to  lielieve  that  itJ  ncarlv  tlie 
-ame  way  .as  two  men  ha\e  -ometimes  indt  penilentlv 
hit  on  the  very  s,ime  invention,  so  natural  selection, 
working'  f'>r  tlie  irood  of  each  heint^  ami  taking:  advaii- 
ta^'e  (if  analoirous  variations,  has  som'-times  modified 
in  very  nearly  the  same  manner  two  parts  in  two 
oriranic  hein^'-,  wliicli  hfin^rs  owe  hut  I;itlt'  of  their 
^t^Ultu^e  in  common  to  inheritance  from  the  -ame 
ancestor. 

Althmitrli  in  many  cases  it  is  most  difficult  to  con- 
jei'lure  hy  what  traii-Itions  ortrans  could  have  arrived 
at  their  prc-ent  state  ;  yet,  coiwiderinir  that  the  pro- 
{M>rtioii  of  liviii'j-  and  known  forms  to  the  extinct  and 
unknown  is  very  small,  1  have  heet)  astoni-hcd  how 
rarely  ,an  orran  vnii  he  named,  towards  whii'li  no  tran- 
sitioiial  irrade  is  known  to  lead.  I'lie  truth  of  thi- 
remark  is  indeed  sliown  hy  that  ohi  hut  somewhat 
exa^rircrated  c^non  in  natural  liistory  of  *  Natura  non 
facit  sallum.'  We  meet  with  this  admis^iion  in  the 
writiiiiTM  of  almost  every  oxperienced  naturalist;  or, 
as    Milne    K/<1  wards   has   well   e.xpre«««(-d    it.    Nature    is 


I'l 


S^^=-.--i 


!)IFH(  I  i;riK.s    ON   TIIKOHV 


175 


pKMlijr.il  iti  variety,  Imt  iii::s.':inl  in  iiinovafidii.  \V\i\-, 
•  •n  th«  theory  of  Creation,  nhouid  thin  U*  so'  Why 
'hoihl  all  th«»  parts  atul  nr^'atis  of  tunny  iii<l.|H'inlfiit 
h'  /iiiT-',  eath  >;ii|i|)(>«*oil  to  have  ]>vvn  «»'{iarat»>lv  rn-alctl 
f'T  its  proper  plarc  in  nature,  he  so  eomrnonly  linked 
liiu'other  hy  jrradu.ited  steps?  Why  hhouhi  not  N.it'ire 
have  tak.-n  a  h'ap  from  «itrJi('tiire  to  struet  iiro .'  On 
'he  theory  of  natural  srlection,  we  «'an  eleariy  iimler- 
-»  itid  vthv  she  sh(»i]!(l  not  ;  for  n.-ttnral  s«-let  iion  ran 
3'  t  only  hy  takinij  a<lvantatre  of  >h^ht  stice*  -yive  varia- 
tions ;  ^h.'  ean  nev»T  take  a  leap,  hut  must  ailvance  !>> 
the  sliiirte^t  and  sh)v\c>it  stepi. 

'ir>j'in.<i  of  I'lttlf  iifijmrfiit  irufiortmire. — A»  natural 
M-h'ciiiin  a<-U  hy  life  and  death,  -hv  the  jnewcrvation 
of  individuals  v^ith  any  fa\«»urahle  variati-ii-,  and  hy  the 
de>tniction  of  those  with  any  unfavourahle  deviation  of 
strii.'ture,  -  1  have  sumelimes  felt  muih  diffuMilty  iu 
iinderstandiiiL'  the  ori;;in  of  nimple  parts,  of  which  the 
iiMporfance  d(f<-i  not  seem  sufllcient  to  rauso  tlie  pre- 
servation of  suciessively  varyinjf  individuals.  !  have 
sometimes  felt  as  mueh  diHieulty,  though  of  a  very 
fiitfiTfiit  kind,  on  this  head,  as  in'the  easf  of  an  orirari 
1-  pi  rtc.  t  and  comjilex  as  the  eve. 

In  ih.-  Iif't  place,  we  are  much  too  i^-imrant  in  re^rard 
lo  the  whole  economy  of  any  o>ie  orjjanic  heiii;;,  to  say 
what  slij^dit  nKKliticatiotis  would  Ite  of  importance  or 
not.  In  a  former  chapter  I  hav«;  jfivon  instances  of 
most  triiliiii.'  characters,  mi,h  as  the  down  on  fruit  and 
the  rohwir  of  its  ih-sh,  which,  from  determininj;  the 
attacks  of  in-ect-s  or  from  heinjf  correlated  with  con- 
stitution.il  di;icrences,  mitiit  assuredly  he  acted  r,n  by 
natural  selection.  'Hie  tail  of  the  jriraff,.  |o„ks  like  aii 
«rf;ficKil!y  constructed  !!y-f1apper  ;  and  it  sfj'uis  at  first 
iiicri-dihle  that  this  could  have  l»e(«n  a<iai»te<l  for  its 
prevent  purpose  hy  succes,>i'.  e  slitrht  motiiticalion-.  each 
better  and  better,  for  so  triliiiiL'-  an  ohiect  as  driviru' 
away  tiies  ;  yet  we  should  i>ause  before  bein:r  too  posi- 
tive even  in  this  case,  for  we  know  that  the  d.-tribu- 
tion  and  exieteuce  of  cattlo  aiid  other  aiiimaltt  in  South 


I 


•"<'] 


MICROCOPY    RESOLUTION    TEST    CHART 

ANSI  and  ISO  Tf  1'  CHART  No    2 


1.0 


I.I 


1.25 


^'l  Ml  2.8 

2.5 

iH  IP'        2.2 

t  1^ 

2.0 

u 

1 

t.    ^ 

1.8 

l.4_ 

1.6 

^     APPLIED  \t\A/\CE 


'er.   New    York         1*6 
-82  -  0300  ■   Pfnr,. 
.88  -  b984       •  :. 


17fi 


ON    I  UK   t)KI(;i\    OF   bI'K(lKS 


America  ali-uliiU'ly  d"|'':i(l<  on  tlu'ir  jhh.t  nf  r<'>i.'<tini; 
tli«;  Httarks  of  in-^fct.".  :  -.o  tl,;it  itiili\  uiti.iU  wliich  coiilil 
by  any  nif.-in-;  (IcUTKi  tliftn^t-h  (■>  froiri  tliese  mimU 
piicinit>,  w.iuid  l>e  alilf  t(i  raiiu'c  iiitn  iit.'w  pastiinw  and 
liiii><  iraiii  .'i  ^Trat  at!'. .intairt.".  Jt  i-  not  tijal  \\ni  lar^T'T 
qua-lnijiols  arc  artiii'.ly  iii'>trny('(i  (cm  cjit  in  »iiin«'  rare 
ca-rs)  !.v  fli»'s,  liut  t'lcy  arf  inct-^-aiitly  li.ira->st'(l  and 
lln'ir  h-tr(Mi;.'th  rrdu'cil.  ~n  tlial  thev  are  u\<>vt'  >ijl>;»'(  t 
It)  iii-»:.is<',  i)r  not  so  \M'li  rnaiilcd  in  a  iiuniiiij  <ii'ai-ili 
t.(»  ■^•'arcli  tor  fixid,  (ir  to  c^fajic  troin  l)fa-t-  of  Jiri'v. 

( )r^'an-;  niw  of"  triiiin^r  inijiortaMrt*  lia'.c  [iroliaMy  in 
KOinc  ra>o-  1»»^(MI  ot  li'irli  iiM|»<irLaiir('  to  an  »'ar!v  |>ro- 
j.'t'nitor,  aTid,  after  iiavin;;  (ummi  .slowly  jM-rto  tfd  at  a 
foriiMT  pcriud,  lia\«  lic»'n  tran-rnittcd  in  iicarlv  tiie 
k;hiio  Ntatc.  alllimijfli  now  iM'conm  id  vcrv  >lii.'lit  use; 
and  afiy  act  "ally  innirioii-i  deviations  in  their  ^<tnlcture 
will  always  have  been  chctlvcd  hy  natural  sele.-tiori. 
Si-,'in:j;  liow  iinjiortiint  an  oiiraii  of  locoino'ion  the  tail 
i^  in  nio>t  aquatic  animals,  if.-;  treneral  prc-cnce  and 
ii'^k'  tor  many  j»ur|K)>es  in  so  many  land  aiuniaK,  whirh 
in  tht'ir  iunii^  or  ri»odituHl  swnnlil.-.ddcrs  hetrav  their 
li'jnatir  oriirin,  may  perhaps  he  tiiiis  accoiiiited  tor. 
A  Acll-(le\ehiped  tail  ha\  in;r  heen  tunned  in  an  a'juatic 
animal,  it  nii::lit  suli^i'tjiu-ntlv  coiiu'  to  lie  worked  in  for 
all  ^o^ts  of  piirpcj^c.  a.s  a  li\ -llajper,  an  oru^■ln  ot  pre- 
hen-irui,  or  as  an  aid  in  tiirni;i:j-.  as  witli  the  do;:, 
thoiiiili  the  aid  mii-t.  he  sliirlit.  tor  the  hare,  witii 
har-.tlv  any  t.iil,  can  douhle  (jiiickly  enoii::h. 

Ill  the  «-<'i-ond  [dare,  we  may  sometni.c-:  attribute 
importance  to  characters  wlii(  h  are  reali\  of  very  liltle 
impi»rtance,  and  "liiih  ha\e  or'^rinated  from  <ju;te 
sei onilary  can^e-..  ind»  pen  ientiy  of  natural  si-lcction. 
W'e  should  rememiier  ttiat  climate,  food,  etc.,  prolia'dy 
li.i' e  >ome  little  direct  inlluence  on  the  or^ranisation  ; 
ttiat  characters  reappear  Irom  the  la\s'  o('  reversion  ; 
that  correlation  of  ^jfpowtli  will  have  had  a  mo>t  im- 
portant inthience  in  modii'yinir  various  structure-"  ;  and 
luially,  that  sexual  selection  will  otu-n  iiave  larirels 
moditicd  the  e\ternal  character^  (d'  animaU  havni;:  a 
will,  to  .'ive  one  mile  an  aihantaj^e   in   ti;.'titin{;  wiib 


I)i;      (LLTIKS   ON    TliEOFlY 


17 


another  or  in  ch.irmiiiir  tin;  females.  Mnrenvor  whoii 
;i  modification  of  structure  lia.H  |irimanly  ari-t-ri  from 
the  aixive  or  other  uiikiiown  causes,  it  mav  at  tir»t 
have  h«'<Mi  of  no  advatit-iire  to  tlie  Hjtetie!*,  but  may 
Muli>t'«|iifiitiy  liave  i^'esi  taken  advantaije  of  liv  tlie  lio- 
sceiidaiits  of  the  spi-cie-  under  ruw  conditions  of  life 
and  with  newly  acjiiired  haliits. 

I'o  ifive  a  few  in.-tance-  to  illustrate  tlM'>e  latter 
remark-.  If  txn'vn  wcmI jM-cker^  aiuiic  hai!  e.\iste<i, 
and  we  did  not  kiMiw  thai  tl/cre  M»>re  riiaiiv  hlai  k  and 
pied  kinds,  I  dare  say  that  v\»«  should  ha\o  thought 
tli.'it  the  jfrj-t-n  colour  nas  a  heautifu!  a(].ii)tation  to 
iiide  tiiis  trt'e-fre^jiietitiiitr  hini  from  ibj  enemies  ;  and 
conse.|UetilIy  that  it  vv;i.s  a  cliaracter  of  imporUm.e  and 
mitrht  have  heen  ar(juire(l  throiit:h  natural  -election  ; 
HH  it  is,  1  have  no  douht  tfiat  the  colour  i.s  du^  to  some 
ijuite  di-tinc-t  cause,  pndiaMy  to  -exual  selection.  A 
irailiiiff  h.imboo  in  tiie  .Malay  Arciiipelaj-o  climl.-  the 
h'ltifst  trees  I>y  the  aid  of  ex<jui-ife!y  constructed 
ho(.ks  clii-tered  around  the  ends  of  the  iiramhe-,  and 
this  contrivance,  no  douht,  is  of  the  hiirhe-t  service  to 
the  }»!ant  ;  hut  as  we  see  nearly  similar  liouks  on  many 
triM's  v»lrich  are  not  climbers,  the  hooks  on  the  Lainh.m 
ni.iy  have  arisen  from  unknown  laws  of  growth,  ami 
ha\e  l)een  subsequently  taken  advantat'e  ot  by  the 
piaiit  undertroin;,'  furtlier  modification  and  l»e<-oniinu  a 
ciimher.  Ihe  naked  skin  on  the  head  of  a  vulture  i- 
treri.  rally  looked  at  as  a  riirect  adapLjition  tor  waMowiri;: 
in  putridity  ;  aiul  so  it  may  be,  or  it  m.iv  jio-^ihlv  lie 
due  t(»  tlie  direct  action  of  putrid  matter  ;  but  we 
should  lie  \ery  cautious  in  drawimr  any  such  inference, 
when  we  see  that  the  skin  on  the  head  ot  the  clean- 
feediiii:  male  turkey  is  likewise  naked.  'Hie  suturt^s 
in  the  skulls  of  youn^r  mannnals  have  been  advanced 
as  a  beautiful  adaptati<in  for  aiilinj:  parturition,  and 
no  doul)t  they  facilitate,  or  may  be  indisjien-alde 
tor  this  act  ;  hut  as  sutures  oerur  in  the  «kul!s  of 
youuL'  bir(is  and  reptiles,  whieh  liave  only  l>  eseaj>e 
iVom  a  broken  vni:,  we  may  infer  that  this  structure 
has    arisen    from    the    laws    of  j^rowth,   and    h;i.s  U'eri 

N 


i 


mMkK- 


■HiMiiiil 


I7M 


ON    TilK    OKRilN    OK   M'ECIES 


f'  } 


tiken  advaiit.uro  of  in    tlio   parturition  of  the   hi:jher 

aiiiiiinN. 

\\  o  are  profoiirnlly  i:rtntraiit  of  tlio  raii-j's  pmdiicinjf 
s'liL'iit  anil  uiiiiniinrtant  vnriatiori^ ;  ami  «♦»  arc  immedi- 
ately made  rnn-cious  of  tliis  l»y  rtiicitiiiiJr  on  tlie  <litfer- 
enres  in  tlio  bree<ls  of  our  domesticated  animalh  in 
<liftei-eiit  (-onntries,  -  nmre  e>jiecialiv  in  tlio  ie.ss  1^%  i!- 
i-ed  rountries  wliere  tlii-re  iia^  Iieen  Itut  little  artificial 
Nfdecfion.  (  ar.'fiil  oh<er\ers  are  convinced  that  a 
d  iFTip  dimato  allcct-  the  L^ro«th  of  the  hair,  and  tliat 
^^ith  the  hair  tfie  JioriH  are  correlated.  Mountain 
l.rf('(N  always  differ  from  lowlaml  hreciH  ;  and  .i 
Touiintainous  country  would  pro>>alily  aliect  the  hind 
liiiiii^  from  exerci'iinu''  tliem  more,  and  orw-ihly  even 
the  form  of  tiie  peK  is  ;  and  tlion  hy  tlie  la*  of  homo- 
loiroiis  variation,  Iho  frnut  limhs  and  even  the  liead 
would  prol.ahly  he  atfected.  'I'he  shaj>e,  al-o,  of  the 
pelvis  mi;rht  affect  hy  pressure  the  sli.ipe  of  the  head 
of  the  yoimir  in  tlie  womh.  'Hie  lal)orioijs  l)reathintf 
iiece<-ary  in  liiirli  re^'^ions  would,  we  liavo  some  reason 
to  helieve,  increase  llie  si/e  of  the  chest  ;  and  a«-aiii 
correlation  would  conio  into  play.  Animals  kept  hy 
"-.ivaij-es  in  different  countries  of\en  have  to  strugj^le 
tor  tjicir  own  suhsistencp,  and  would  t>e  exposed  to  a 
cfrtaiu  extent  to  natural  selection,  and  individuals 
witli  sli^rlitly  diifcrent  constitutions  would  sticcee«i  hest 
under  di;!erent  climates;  and  there  is  reason  to  l>elieve 
that  idiislittition  aiul  colour  are  correlated.  A  trood 
observer,  al-o,  states  that  in  cattle  susceptihility  to  the 
attacks  of  flies  is  correlated  with  colour,  a^;  is  the 
liahility  to  he  pois<»iied  hy  certain  plants  ;  so  that 
ciloiir  would  l>e  thus  ^uhieeied  to  the  action  of  natural 
se'iM  tiou.  Hut  we  .-ire  fir  too  ii^norant  to  speculati" 
O!!  the  relative  importance  of  the  several  known  and 
unkiiowu  laws  of  wuiation  ;  and  I  have  here  alludt-d 
to  thern  only  to  siiow  tliat.  if  we  are  unahle  to  acc(»unt 
tor  the  characteristic  differences  of  our  domestic 
tireels,  whieh  nevertheless  wo  irenerally  admit  to 
ha\e  irisfn  t!irou_r),  ordinary  ireuf  ration,  we  oujjht 
not   to   lay    too   iiiiicL    stri<-is  on   our    limnran.  e  of  the 


DIFIKJ  i;HK>   ON    IflKoKY 


179 


F' 


rnu>iO  of  the  hli^lit  ai 


iai():r<ni>.    (lirit-re.'K 


•?. 


tHfcn   i^pecios.      I   miirht    have  addiu-od    for   tl 


•es   I 


p'ir|)(w«    the   differt>ii( 
.  hifli 


"k«Ml  ;    I 


the 


le- 
ns g<'inii- 
race*  of  mm. 
wfii.li  are  so  stroii:;ly  niarkf.l  ;  I  may  add  that  some 
li'tle  lii:lit  can  a|i[iaroiitly  ho  thrown  on  tlie  orii,'iii  of 
thf-ip  diffprerice-i,  chipi'ly  t'hrouifh  sfxual  >;fle.-tion  of  a 
|i.irtirular  kind,  hut  witii«»ut  here  t'literin:;  on  copious 
d»'Mils  my  reasoning  would  appear  frivolou'*. 

J  he  foreifoinj?  rpinarks   lead   me  to  «iv  a  few  word>i 
on  the  protest  lately  made  hy  Hom«  naturali-^t^,  airaiiist 
the   lit:  itarian  diMtrine  that"  everv  detail  of  structure 
has  heen  j>rodii(ed  for  tlie  pood  ol  its  possessor.      Ihev 
Kelieve   that  very  many  structures   have  heen  created 
fur   heauty  in   tlio  eyes   of  man,   or  for  mere   variety. 
liiH  doctrine,  if  true,  would   he  ahsoluteiv  fatal  to  riiv 
theory.      Vet  I  fully  admit  thai  many  structures  are  ot 
no  direct  use  to  their  possessors.      Physical  conditions 
|,n.hahly  have  had  some  little  effect  on  structure.  (,uite 
M.dept'ndently  of  any  irood  thus  pained.      (  orrelation 
or  i^Tuwih  has  fio  douht  played  a  most  importiint  part, 
and  a  useful   mo<lifi.ation  of  one  part  will   otten  have 
entailed  on  other  parts  diversified  chanfjes  of  no  direct 
iiM'.      ;?o  a<ain   character.-,  whicli  formerly  werfl  u.seiul, 
or    ^vhich     formerly    had     arisen     from    correi.ition    of 
irvi)\\\}\,  or  t  om  other  unknown   cause,  may   reappear 
from   the  law   of  reversion,   thoueh   now  of  no  direii 
u--.      I'he  etfects  of  sexual  selection,  when   displayed 
in   heauty  to  charm  the  females,  can  be  called   useful 
only   in   rather  a   forced   sense.      Itut   hy  far   the  most 
i'nportant  consi<ieration   is  that   the  chief  part  of  the 
oivanis.ition   of  e\ery   heintj  is  simply  due  to  inherit- 
•T.-e  ;  and  conseijuently,  thoutrh  each  heinjr  assuredly 
!«  ^vf'il   fitted   for  its  tda.--   in  nature,  many  structures 
ni.w  ii.ive  no  direct  rela:!..:i  to  the  hahits  of' life  of  each 
s|.ec;es.       Thus,  we  can  hardly  helieve  tliat  the  wef.hed 
'•'•"t  of  the  upland  tr„„se  or'of  the  frijrate-hinl  are  of 

' '    '"^  ■-"•'  ■-"^■"'  :;;rr;:i  ,    -.tc  rarinni:    rn-iie»e    llial    tfie 

sun.-  hones  i:i  the  arm  of  the  monkev,  in  the  for<>-le*f 
ot  the  horse,  in  the  wintr  of  the  hat,  and  in  the  flipper 
of   the  seal,  are   of  special    use  to   tlie-e  animal.s       We 


if^ 


I 


180 


ON     iHK   ORKilN    OK    M'K(  JKS 


may  pafcly  .ittriliule  tlKvo  >triji'tiirps  t^)  inlif riUnrfi. 
Hut  U>  llii-  pr(i;:fiiit()r  of  tlio  upland  ifoost)  ami  of  tlie 
friir.'itp-l>iril,  \vt'l»l»o«i  fp«'t  no  doiiht  wppf  a^  UHefiil  afl 
tfioy  now  ari>  to  tlie  iiiif^t  aipiatic  ot  pxiHliriu  l.inis. 
>o  we  may  U'lit've  that  the  [)ri»:.M'nltor  of  tlie  >'»-al  had 
not  a  flippor,  hut  a  font  nifh  five  toes  titt«'d  for  wnlkini? 
or  ^rra.«|>intr  ;  and  wo  may  furtlwr  ^entiiro  to  h«'l  fve 
that  tlie  -cveral  hone^  in  the  linrtw  nf  tln»  rnonkfv, 
horse,  and  hat,  which  liave  hi-cn  inhcnred  from  a 
'•omni(»n  iiroy'eiiitor,  were  formerly  of  iiinre  sjn'cial  line 
to  that  iiroi:«Miitor,  or  its  |iroirenitorH,  than  tliev  now 
are  to  tlie-o  aiiimals  liavinjr  '■uch  widelv  di\  (>r>.iri»'<i 
liahits.  riieretore  we  may  infer  that  tln'-t»  several 
liotie'  mi^rht  have  heen  aecjuircd  throii^'h  natural  «elee- 
.ion,  ^uhiccted  formerly,  a.-,  iKtw,  to  thf  sever:il  laws 
of  inheritance,  reversion,  correlation  of  trrowth.  etc. 
'■  ience  ever\  detail  of  structure  in  every  livinc  creature 
,  making- ^o:Ile  little  allowance  for  the  direct  action  of 
|ili\sical  cf)nditionv;  »»iay  lie  viewed,  either  as  havint; 
!  een  of  special  u>e  to  some  ancestral  form,  or  as  beintr 
now  of  siiccial  u«e  to  the  descendants  of  this  form  - 
either  directly,  or  indirectly  throuuh  the  comide.v  lawn 
'1  jfrowlh. 

Natural  selection  cannot  possihly  produce  any  modi- 
fication in  any  one  sjiecies  exclusively  for  the  irood  of 
another  sitpeios;  tliitii^h  tlirou^liout  nature  one  species 
incessantly  takes  advanbuxe  of,  and  jirotiLs  by,  the 
structure  of  another.  Hut  natural  selection  ran  and 
doe-s  often  produce  structures  for  the  direct  inpiry  of 
other  -.pecies.  as  we  see  in  tlie  fans:  of  the  adder,  and 
in  the  ovipositor  t\f  the  ichneumon,  by  wliich  its  eye^ 
are  deposited  in  the  li\inj.r  bodies  of  otlier  insects.  If 
it  ♦•ould  be  pntved  that  any  j»art  of  the  structure  of  any 
one  species  had  been  forned  for  the  exclusive  g-oid  of 
anotlier  sjKH-ies,  it  wouhl  annihilate  my  theory,  for 
Buch  ciiuld  not  have  been  produced  throutrh  natural 
xelection.  Althouirh  many  statements  may  be  found 
ui  works  on  natural  history  to  tins  effect,  I  canm»t  find 
even  one  which  seems  to  me  of  any  weitrrit.  It  is 
admitttnl  that  the  rattlesnake  ha"  a  ^M)ison-fanir  for  ite 


DIFFKULTIES   ON   THP:()KY 


IHl 


own  defeni-e  ami  fur  the  dpstructinn  of  its  prov  ;  hut 
iH»ni#>  .lutliorn  hiippose  that  At  the  same  time  thi^  Miake 
in  f urni-ht'il  with  a  rattle  for  it»  own  iiijiirv,  namely, 
to  warn  its  prey  to  e»»-ane.  1  would  almost  as  noon 
holieve  tliat  the  cat  curU  the  end  of  it.«  tail  wlien 
pr«'parin>f  to  spriiisf,  in  order  to  warn  the  doomed 
mouse.  IJut  1  have  uot  space  here  to  enter  on  thia 
and  other  Huch  c.ises. 

Natural  seltMtioii  will  ne\er  proiluco  in  a  tieiiii? 
anything  iiijurious  to  itself,  for  natural  ^election  actn 
Mdely  hy  and  for  the  trood  of  each.  No  oriran  will  Ite 
formed,  as  I'aley  has  remarke*!,  for  the  purjtose  of 
cau>iii'.'  jKiin  or  for  diiinjf  an  injury  to  its  po>>e,ss<ir. 
if  a  fair  halaiice  l>e  Ktruck  hetv\«'en  the  trood  and 
evil  caused  hy  each  part,  each  will  he  found  on  the 
whole  advantageous.  After  the  lap-e  of  time,  under 
chani:in>f  conditions  of  lif",  if  any  part  comes  to  ho 
injurious,  it  will  be  modified  ;  or  if  it  be  not  so,  the 
bein^'  will  hec-ome  extinct,  as  myriads  have  l)ecom« 
e-\tinct. 

Natural  selection  tentls  «)nly  to  make  each  ortranir 
heifitr  as  |>erfe<-t  a.«,  or  slightly  more  perfect  than,  the 
other  inhabitants  of  the  same  country  with  which  it 
ha*  to  strutrtfie  for  existence.  .\nd  we  see  that  this  ia 
the  dejfree  of  {)erffcction  attained  under  nature.  The 
«Midemic  produi;tioris  of  New  X  'anil,  for  mstam  e,  are 
(•crfect  one  compared  with  another  ;  hut  they  are  fiow 
r.ipiiily  yieldintr  before  the  advaficin<f  legions  of  planUi 
aiid  anifnal.s  i.'itroduce*!  from  Kurope.  .Natural  -flec- 
tion will  not  produce  absolute  perfection,  nor  do  we 
.ilways  uieet,  a.s  far  as  we  can  judtre,  with  this  fiitrh 
suiwlard  under  nature.  The  correction  for  the  ai>erra- 
li<in  of  lio^ht  is  said,  on  hi<^h  authority,  not  to  be 
{.erfect  even  in  that  most  [)erfect  ortran,  the  eye.  If 
our  reason  leads  us  to  admire  with  eiilhuviasm  a  multi- 
tude of  inimitable  contrivances  in  nature,  this  same 
rea**on  tells  us,  thoutrh  we  mav  easily  err  on  both 
sideu,  tiiat  some  otticr  contrivances  are  le^s  perfect, 
(an  we  consider  the  *tiiii:  of  the  wasp  or  of  the  bee 
a-   i>erfect,  which,  when   u-ed  atainst  manr  altackiiifi; 


182 


ON    THK   OHKJIN   OK   SPKCIKS 


iuiiiial.s,  carihot  be  witlnlrawn,  u^luis  to  the  backward 
Hcrratiires,  and  ho  itieviUihly  rauseu  the  death  of  thp 
iriKert  by  trariiij;  out  its  vis«'ora  r 

If  we  look  at  the  stint:  of  tjie  Ik-*-,  a**  haviiiff  origin- 
ally  existeil   in   a   remote   progenitor  as  a   horinjf  and 
serrated  iriMniinent,  like  that  in  so  many  nu'mJ»crs  of 
the  name  jfreat  order,  and  whirli  has  he.  :i  niodifuMj  hut 
not    perfert,.,!    f,,r  \\<  pr.'-ent    j.^rpoM'.  with    the   j.oison 
ori;rinalIy  adapted   to  cause  ffalls  Kiih>e(jiieutly  intensi- 
fied, we  ran  jierlians  understand  how  it  is  that  the  iik<« 
of  the   stintr   should   so   oltfi    cause    tiie    insect's   own 
death  :   f(.r  if  on   the  wliole  tiif  power  of  Htin^'in^'  U' 
useful  to  the  commiitiity,  it  will   fultil  all   the  re-juire- 
nients  of  natural   selection,   thouirli    it   may  <ause  the 
death   ot  m.rno  few  niemlwrs.      If  we  admire  ttie  truJy 
wonderful  power  of  scent  by  wlijch  the  males  of  many 
in>e.  Ls  find   their  females,  vau  we  admire  the  pr<»duc- 
tiori    for   this  sintrle   purpose  ot    thousands  of  drone>, 
'vhich   are   utterly   useless  to   the   community   for  any 
•  ■th.-r   end,  and    which   arc    ultimately  slau^riitere*!    In 
their  industrious  and   sterile  sisters?"    It  may  be  ditii- 
ult,   but   we  ou<rht   to  admire  the  savage   instinctive 
iiatred   of  the  quetn-bee,  which   urpes  her  instantly  to 
■lestroy  the  yountr  queens  her  dauuhtcrs  as  soon'   an 
l»orn,  or  to  perish  lierself  in  the  combat  ;  for  undoui.t- 
<<ily    this    is    for    the    pood    of   the   community  ;    and 
maternal    love  or  maternal   hatred,  tliou^h   the   latter 
turtunately  is  most  rare,  is  all  the  same  to  the  inexor- 
able  principle  of  natural  selection.      If  we  admir.'  the 
several  in/mious  ctuitrivances,  by  which  the  tiowers  of 
the   orchis    and    of   many   other '  jdanti*    are    fertilixnl 
ihrnutrh    insert    a^'ency.    can    we   consider   as    equally 
perfect   the  el.iboration  by  our  rir-trees  of  dense  cloud's 
nf  pollen,  in  order  tliat  a  few  trranuies  may  be  wafted 
■y  a  <  hance  breeze  on  to  tiie  ovules.- 


<u>i.,u.iryo/'%:i.f.>r.~\Vv  have  in  this  chapter  di*- 

>>e  Lr-ed  a-aiiist  my  theory.      Many  of  them  are  very 
-erious  ;  bat  I  tliink  that  in  the  di>cuUion  lijrlit  Las  Ihu  n 


UIKKICrLTIKb   ON   THKOUY 


183 


tlirn'.vn  oil  several  f;i(tw,  whirli  om  tlie  theory  <>f  indp- 
ii»MiiitMit  arU  <•!  «ri'atinri  are  uttorlv  oWsciire.  ^V  e  li.tve 
'•ecu  that  sjK'cipt*  af  any  otie  {xTicHi  are  ii<it  iinlctiiiitoly 
'  arial'h',  ami  are  not  liiike<l  totrt'ther  by  a  iniiliiluile 
of  iutornuwii  itf  irrai!ati(iii>.  j>arily  Id'iau^f  tlio  nn  ««'.«•>  of 
natural  >«'lri  ti(>ii  will  always  In*  \fry  >-low,  and  «ili  .Kt, 
at  any  (nu*  time,  only  on  a  vfry  tew  (nrni!*  ;  and  jiartlv 
>>o<  aurte  the  very  |»riMcs-  ot  natural  M-Uvtinn  alnio.st 
implies  the  continual  sujtplantini.'-  and  extimtioii  of  j>re- 
re<linir  and  internu'diate  gradations.  <  lo><'ly  allied 
«|K.M-ies,  now  living  on  a  continuous  area,  mu^t  otten 
have  heeii  formed  \*hen  tlie  ar»>a  v»a^  not  continiiou**,  and 
viien  the  itinditioii>  of  life  diil  not  in^enNihly  ^Taduate 
may  from  one  part  to  another.  \Vhtii  Iwo  varieties 
■.re  fornuMl  in  two  districts  of  a  enntinuous  area,  an  in- 
•»  rnieiliate  \ariety  will  often  he  forme«l,  fitted  for  an 
intermediate  zone;  hut  from  reasons  as^itrned,  the  inter- 
mediate variet}  will  usually  exist  in  les.st'r  numhers  tlian 
the  two  forms  which  it  coniieets  ;  «:onse<|nenlly  the  two 
latter,  during  the  course  of  further  modifcation,  frorii 
f*xistintf  in  greater  numhers,  will  have  a  trreat  advanfaice 
over  rhe  less  numerous  intermediate  variety, and  will  llius 
ireuerally  sueceed  in  supplanting  and  exterminatin:;  it. 

\\  e  have  seen  in  tliiv  chapter  how  cautious  we  shouhl 
t>e  in  <-oiu  ludiniT  that  the  most  ditlereiit  hal.it,s  of  life 
lould  not  graduate  into  each  otht-r  ;  that  a  hat,  for 
iu-tan<e,  could  not  have  heeii  Inimeii  \>\  natural  r-«-lt'<'- 
tion  from  an  animal  whicii  at  fir>t  could  only  taiie 
ihroueh  the  air. 

\\  e  liave  seen  that  a  >j>ecies  may  under  new  t«uidi- 
tiou.s  tit  lite  (  haiiire  Us  h;ihit>,  or  have  diver^itie^l  hahits, 
Aith  some  liahiLs  very  unlike  tho«.f  of  it-  nearest  con- 
treners.  Hence  we  can  understand,  hearing  in  mind 
that  each  orf^anic  Iteinc  is  tryin^,'^  to  live  wherever  it 
ran  live,  how  :t  has  ari-eii  that  ti ere  are  uplami  uee>e 
Mth  wfhhed  feet,  ground  vvooilpeckers,  diving  thrushes, 
ui.i  petreU  with  the  hahits  of  auks. 

.•\iuiougii  the  ix'iief  that  an  or^raii  so  perfect  as  the 
eve  could  liave  heen  tcjrmed  l)y  natural  ^electiou.  ia 
more  than  ent)ugh   to  stagger  any  one  ;  yet  in  the  case 


-JS'A 


§m*\m:^^^ms^'k 


...j*^^ 


IH4 


ON    THK    OKKilN    OF    s|'K(  IKS 


of  any  orcan.  if  we  kinnv  of  a  l„ti^  s.-ripM  cf  t'nulationi 
m  .-..rTii.leNitv,  ear),  ^'ood  for  ify  po^M'-or,  then  ijri.i.'r 
rli;iM:.'mt'  .•..ii.iif ioii.  of  lif,.  tl.rr..  is  „<,  lotr,,.;.!  j,„,,o^^i- 
I'ility  III  tlio  arriiiir.'r.u'iit  of  ,injr  n..„».ival,|t.  <i«.;.-Trf  of 
ptTNTtion  throuu'li  natural  srlc,  tion.  In  tJie  ras^«  in 
wliicli  H..  kn..vv«,f  no  int^rmp.liat.' or  traii<ifi<»;ia|  nXMet 
««  slioiild  No  very  <-a.ifioii«  in  con.  huiins:  that  nr.ne 
<  on  I.I  liavo  oxiste.!.  for  the  Jiomoloir:.s  of  rnanv  or,fan.H 
an. I  tli.'ir  nit.-rTni'.iJati.  states  -liow  tliat  WDndfrfiil  meU- 
MiorplioM-  in  tun.ti.»n  are  at  loast  |,o<>il,lp.  }  „r  iintanre, 
a  s>*Mn-!ila.i.i«'r  has  apparpfitiy  Wen  convrrt»'<i  into  an 
air-hr..af  luinr  \uuu.  I  In-  varne  oriran  havnii:  i.erf..rme»l 
Kimultan»..,ii.lvMery.litr«.n'ntfijn.ti..rH,an.i  th.-n  haviriff 
l).'««n  s,„.rialiM'.i  for  one  function  ;  and  tw..  very  dis»iru-t 
orjrans  havinji  perfornie.i  at  the  Mani«  time  the  s;inie 
funrtion,  flu-  one  having'  heen  i)erfe<ted  wliiUt  aide.! 
hy  the  other,  must  often  have  largely  fa.ilitited 
transitions. 

\\  e  are  far  too  i;rnorant,  in  almost  every  case,  to  be 
enabled  t.)  a^-ert  that  anv  part  or  or^'an  'is  so  unim- 
portar.t  (<■  the  welfare  of  a  spe.ies,  that  modifications 
in  Its  Htru.tnre  could  r..,t  have  heen  slowly  accumulated 
hy  means  ..f  natural  sele.tion.  IJut  we  may  cnti-jently 
heheve  that  many  nio.iifications,  wh..llv  due  to  the  laws 
ot  irr.)Mth,  and  at  llr^t  in  no  wav  a<ivantai:eous  to  a 
sj.e.ies  have  heen  sul.se-juentlv  taken  advantage  of  hv 
tlie  still  fiirth.T  modified  descendants  of  this  s{K.cies.  W'e 
may,  aUo,  believe  that  a  part  formerly  of  hiirh  import- 
ance has  often  been  retained  (as  the  tail  of  an  a.|ualic 
animal  hy  its  terre-trial  descen.iant.s},  thouirh  it  has 
be.-ome  of  nich  small  importance  that  it  .•oul.l  not,  in 
Its  present  state,  have  been  a.-<i.iire.|  by  natu-al  selec- 
tion,- a  i.ower  which  a.ts  s.dely  by  tlu' preservation  of 
prctitable  variation-  in  tlie  strutrp-le  r,.r  life. 

Natural  selection  will  produce  nothiiiir  in  one  s|>eciet< 
f.)r  the  e.xdusive  p..od  or  injury  of  another;  though  it 
may  well  produce  parts,  ..r^'an's,  and  excretions  hrtrhly 
iisi!;;i  or  i\fii  ii,ii|s,„.„sai)ie,  or  hi::iiiy  injurious  to 
another  species,  but  in  all  ca.ses  at  the  same  time  u.^ef>Jl 
to  tlie  r.v*,„.r       Natural  selection  in  each  w,  11-stucked 


[jESr*"^ 


DIFFK  ILTIKS  ON    IIIKOKY 


1B5 


roiiiitry,  tuuMt  act  chiotly  throiii^fi   tho  fomix'tjtiiti   of 
Oif  iiilialiirant^  one  h itii  aiidtlicr,  and  fniiscqiioiitly  will 


[irtMlijie  jKTffi'iioii,  or  strTijrth  tii  the  l»attle  lor  life.milT 
.i«  .  nnliiijf  to  tlif  Htamiard  uf  tli.it  rountry.  Heme  tl.»' 
irili.ii>itaritj*  of  one  roijiitry,  ^reneraily  the  »itiiaiUT  one. 
Will  titXvn  yielil,  h8  wp  M'e  tlit'V  do  yield,  to  the  iiiha- 
liitaiitx  of'aiintlipraiid  c«'iii'r.ill\  l.irifer  rountry.  For  in 
the  laruMT  couiitry  there  will  have  oxi>.ted  more  indi- 
viduals, ami  more  diversified  fornin,  and  the  fom|>etition 
will  have  Keen  severer,  and  thus  thestandanl  of  iM-rfec- 
tion  Hill  have  l)een  rendered  hitrher.  Natural  selettion 
\*ill  not  necessiirily  pro<lure  ahsolute  |>ert"e«tion  ;  nor,  an 
fir  as  wp  tan  judjje  hy  our  limitetl  fiu'ulties,  can  al)S<ilute 
perftH'tioti  ]i«  everywhere  found. 

On  the  theorv  of  natural  selection  we  ran  i  u-arly 
iindersUnd  the  fiill  meariini;  of  that  ol<l  <-anori  in  natural 
history,  'Natura  non  facit  salturn."  I'lii-i  i-anon,  it 
we  look  only  to  the  present  inhahitafits  of  the  wtirld,  in 
not  strirtly  correct,  hut  if  we  include  all  those  of  j«a.st 
tinieH,  it  must  hy  my  the«>rv  \te  strictly  true. 

It  is  generally  ackiiowledued  tliat  all  uriranir  heings 
•  ave  heen  formed  on  tw<>  treat  law.s- -I  inty  of  Type, 
Hiid  tlie  (  onditions  of  Kxistence.  By  unity  of  tyi)e  is 
rT.eant  that  fundamenUil  aurpemetit  ifi  structure,  which 
we  see  in  ortrainc  hemirs  of  tlie  siiine  da.-^,  and  which  is 
(^uite  ir)de|ietjdent  of  their  hahit«  of  life.  On  my  tlieory, 
unity  of  type  is  explained  hy  unify  of  descent.  The 
exjire^sion  of  conditions  of  existeru  e.  «o  often  insisted  on 
hy  the  illu»trii)us  (  uvier,  is  fully  eftil. raced  hy  tlie  prin- 
ciple of  natural  s«'!ection.  For  natural  selection  a(  Ls  by 
either  now  adaptinj;  the  varyini;  part.*  of  eiuh  iicin^f  to 
it*i  ctrtranic  an<l  inortfanic  conditions  of  lite  ;  or  hy  having 
adapted  them  durintf  l<)nt-{>a>t  jH-riods  of  time  .  the 
adaptations  heiiiji'  aided  in  >(>rne  ta-se.s  hy  use  and  dis- 
u>.e,  hein;;  sliirhtly  affected  hy  the  direct  action  of  the 
external  conditions  of  life,  and  heinij  ifi  all  cases  suli- 
lected  to  the  several  laws  of  trrowth.  Hence,  in  fa«t, 
tlie  law  of  the  Conditioas  of  Kxi>tence  is  the  hiifher 
law;  a>i  it  includes,  thrim^'h  the  inherr.ance  of  former 
a<i.iptation<,  that  of  f'nitv  of  Type. 


^n 


en  A  1' IKK    VII 


I  s  - 1 1  .s  n 

i;i»tlni-U  c<in,i.»rMl.le  »iUi  I  »lnu,  uut  lilll.rent  in  tlirir  ....jtin- 
jintii-tfl  j:r«.|ii.»ti-.J  A|.lii.l.-.<  >ii>l  MiU  Init.ii.  In  varul.lc— 
!>•  Mi.»ti.'  iiiitiii.  tt.  their  ..li^'iti  .N«tiir«l  iiigtlmti ..(  tl.r  .  u.k.". 
uttiil..  arhl  puia^idc  t»i-i, -M»ve  iii,ikii.>;nitB  Huv  Iff  lt» 
i^<l.  I'iakiiiK  liutiM  t-imii.  ultic*  on  tl,.  thi-.rv  ..f  tlir  Nuiui.il 
hchiii.iij  i.f  in, mil  u     .NfuU-r  or  it<  uk-  iij»ccu'  Saimoary. 

Tbk  Mjlfject  of  iii>tiut:t  nii;,'lit  hav«.-  \>f^^n  worked  into  the 
I  r.\  inns  cli.ij.lers  ;  hut  I  liave  thoiitrlit  Dial  jt  wduld  Iw 
mori.  c(mv»;iiitMit  to  treat  the  suhjctt  te|«irately,  «'sih«- 
cially  as  ro  Moiiil»>rfiil  an  iii.xtiiict  aa  that  of  thr  Iiivc- 
i»eo  makiiii:  its  rolls  will  proliahly  have  n.cjrn-d  to 
niaiiv  rc.Kirrs,  UH  a  <litii«ulty  siitricioiit  to  o\t«rlliroH-  my 

**''''"'^'  *' ry-      I  must  preniist.,  that  I  hav».  nothiiifr  to 

do  wiih  Ihp  oriiriii  of  the  priniarv  iiiontAl  pow.Ts.  any 
rnon-  lliaii  1  ha\.'  willi  that  ot  lifw  itself.  \\  v  arc  con'- 
cerned  txily  with  the  diversitii's  of  instinct  and  of  the 
other  mental  qualities  of  ariimals  \H;thin  th<>  sam»> 
t•la-r^. 

1  will  not  attempt  an\  ijefuiition  of  iuvtinrt.  It  w.-uld 
!mj  tM>y  to  show  that  several  distinct  mentiil  actions  are 
commonly  emhraced  l.y  this  term  ;  hut  every  one  utuler- 
st-nd.^  wliat  is  meant,  wlu-n  if  i^  <ai(l  that  instinct  imj.eU 
IheiucKooto  migrate  and  to  lay  lier  ejfcs.  in  other  hinds' 
nests.  An  action,  which  we  ourselves  >liouM  re.juiro 
experience  to  enahle  us  to  [lerform,  when  performed  hv 
r.i:  .-.;;.:::.;;.  ri.wrc  t.-j.o,  -.iii\  t»v  a  \  t;ry  vounjr  One,  witiiout 
any  expei-i,  n(e,  and  when  |^«rformed  hy  many  indivj- 
di;als  Ml  tl,c  s.-.:,ie  w..v.  wiiliout  their  kn<)\\:n4r  "t«.r  miat 

li;t; 


.^^kSii^&'^M^B^^^smm 


LVSTIN(T 


IR7 


P'irpOM-  It  i»  pprfornuHl,  is  UMially  muI  to  b'.«  iimtiiirUvp. 
Fiut  I  could  kImiv*  that  iinrip  of  tlicno  rhanirtrrs  .if 
iiiHtinrt  ar**  iiiii\«'rsal.  A  little  do-*,  »<*  Tiprre  Hiib^-r 
••inre.-isr-s  it,  of  iinitrmpnt  or  reii-mi,  often  mmes  JMto 
(.lay,  »'\oii  ill  ariiinalH  v.-ry  low  in  the  srale  of  nature. 

lie<lerirk  (  uvier  and   wneral   of  the  older  metaphy- 
sicians  have  «  onijMred   instinct  with   liaMt.      'I  his  cuiii- 
parison  pivea,  1  think,  a  reinarkilily  arcurate  notion  of 
ihr  frame  of  niifi  I  under  whuh  an  instinctive  action  is 
[►ert.irnied,  hut   not  of  it«  origin.      How  nnroiisrioiisly 
many  hahituai  actions  are  performed,  indeed  not  rarelv 
in  direct  o|>|>o«.ition  to  our  conscious  will  !  yet  thev  niav 
l>e  nioditied  hy  the  v*ill  or  reason.      Hahits  e'a.sily  iM'come 
a«f.ociate<l  with  other  hahits,  and  with  cortAin  |H«riod*  of 
'.mc  and  sUl«»<of  the  iM.dy.     When  once  ar()uired,  they 
often   remain  consUtnt  throutrhout  lif»-       Seven!   other 
points  of  rese'nhlance  between  in.stinct-s  and  hahits  could 
>e  pointed  iiut.      As  in  repeating  a  neli-known  none,  so 
in    nistinctfl,  one  action    follows  anoilier   by  a  sort  of 
rliythm  ;  if  n  |>erson   Iks  interrupted   in  a  Hon|r,  or  m 
rept-atinjf  auythin;,'  hy  rote,  he  is  jrenerally  forced   'o 
go  iiack  to  recover  the  hahituai   train  of  tlioujflit  :  st» 
1'.  Hubor  found  it  was  with  a  caterpillar,  which  makes  a 
•  ery  complicated  hammock  ;  tor  i(  he  took  a  caterpillar 
i^liich  had  «-oniplete<l  iU  hammi>ck  up  to,  Kay,  the  sixid 
-Liiife  of  construction,  and   put  it  into  a  hammock  com- 
plet«^  up  only  to  the  thinl  statfe,  tlie  caterpillar  simply 
re-performed   the  fourth,  fifth,  and   sixth  staires  of  con- 
-'ruction.      If,  however,  a  caterpillar  were  tiken  out  of 
■I  hammock   made  up,  for  ii.>tance.  to  the  third   sLnce. 
;.rid  were  put  into  one  finished  u[>  to  the  sixth  ^1:0:0,  ^n 
that  miK  li  of  its  work  was  already  done  for  it,  f'r  from 
fei'iiin:  tiie  iM-iietitof  this,  it  was  much  enil)arras.sed,  and. 
in  order  to  complete  its  uammock,  ^e«•med   fon  ed   to 
sUrl  from  the  third  sUjfe,  where  it  had  left  off  and  thiif 
tried  to  complete  the  already  nnishe<l  work. 

If  we  sujtpose  anv  habitual  act  win  to  become  in- 
hrrite.i  -and  I  tlnnk  it  can  Iw  •.I,ow,i  thai  this  dop* 
sometimes  hap|>eri  then  the  re-.rnblance  between  uhat 
oripi'ially  w.is  a  habit  and  an  instinct  U'.onu-s  so  close 


IHH 


ON    T!iK   ORIGIN    Ol     Si'KdKS 


;i>  liiit  to  \tei  diKtinjfuished.  if  Mozart,  iri>t(>ad  of  i)layint? 
tli(>  fiaiiofort*'  at  thrre  years  old  with  w<)n<ler»uily  littlr 
pracrii-p,  hail  played  a  tune  with  no  practice  at  all,  lu« 
niiL''!:!  truly  he  said  to  have  done  ^o  in-tinctuelv.  Hut 
it  «,iiiid  he  the  rno«t  'ieriuuM  error  to  sup[io-e  that  the 
gTiMtcr  iuinil»»'r  of  iijst;iict.-<  have  heen  acijuired  hv  habit 
ill  on<«  ueiieration,  and  then  transmitted  t»y  mnentance 
to  Huci  e<>dinc-  ?eneration>'.  It  can  he  clearly  >howii  that 
the  rimst  •.vniidertul  in.->titict>-  witli  which  we  are  ac- 
•ILiainted,  namely,  tho^e  of  the  lii\e-hee  and  of  many 
^uis,  could  not  [inssihly  liave  heen  tlius  aci)i;iied. 

It  will  he  univvsaily  admitted  that  in>:;iict,s  are  an 
important  as  cj)r[)oreal  structure  for  the  welfare  of  each 
•jpccies,  under  its  present  conditions  of  lih-.  Inder 
chan^-ed  condit:oni  of  life,  it  is  at  least  p<i>*jlde  that 
sii::ht  riioditications  of  instinct  miulit  he  proiitahle  to  a 
spciies  ;  and  if  it  can  he  shcmn  that  instincts*  do  var\ 
t\e-  so  little,  tfien  I  can  see  no  diJFn  ultv  in  natural 
selection  preserviinr  and  continually  accumulatiiiff 
variatiicis  of  instinct  to  any  extent  that  may  be 
profitable.  It  Ih  thus,  as  I  believe,  that  all  the  most 
complex  and  wonderful  instincts  have  ori:rinateii.  As 
moditications  of  corjKneal  structure  ari-e  from,  and  are 
increased  by,  use  or  habit,  and  are  iliminished  or  lost 
Uy  disuse,  so  I  do  not  doubt  it  has  been  with  instincbj. 
Hut  I  believe  that  the  effects  of  habit  are  of  ijuite 
suiiordinate  importance  to  the  effects  of  the  natural 
ielection  of  what  may  be  called  accidental  variations  of 
in-iiiicts  ;-~  tiiat  is  of  variations  produced  by  the  same 
unknown  causes  which  produce  .4if;ht  deviations  of 
i»i)dily  structure. 

No  complex  instinct  can  pos>ibly  he  iirodm cd  tbrough 
nitural  selection,  except  liy  tlie  sl^w  and  »rradual 
accumulation  of  numerous,  sliirbt.  vet  j>rofitable, 
variations.  Hence,  an  in  the  ca -e  of  corporeal 
Mtri.'itures.  we  ouiriit  to  find  \u  nature,  lutt  the  actual 
transitional  ^rraditimis  by  which  each  complex  iiiPtiuct 
b.in  iifcu  acquired  for  these  couiij  he  tdund  only  ui 
the  lineal  ancestors  of  ©;ich  specievS — but  we  oujrht  to 
find  111  tfi«  collateral  linen  nf  deaceiit  some  evidence  of 


*^&'- 


INSTINCT 


189 


mich  jrraiiztions  ;  or  we  oui^ht  at  least  to  be  alile  to 
«;how  that  graHatioiiH  of  some  kinil  are  possiblt*  ;  and 
tluH  we  rcrtaiiilv  laii  <lo.  1  have  })oon  surpri><«'<l  to 
tiiid,  makiiiir  allow.iure  for  the  iii<tiiiftH  of  animal- 
having'  Im'om  Imt  little  ohservwl  except  in  KiirojM>  atid 
Nortii  AriH'ri''a,  and  for  no  instinct  hi'inL'  kno«ii 
amo;  iTst  I'xtiiict  sy»eci(>«,  liow  very  trpni'ral!y  uTadatimw, 
Icadiri  ■'  to  the  most  comjilex  institMts,  can  \»'  discoveri'd. 
('liain^'s  of  instinct  may  sometimes  Im*  facilitated  l>v  th. 
same  species  haviiiir  ilitfereiit  instincts  at  dirierepji 
perind^  of  lire,  or  at  different  seasons  of  the  year,  >>' 
wlien  placed  under  different  circumstatices,  etc.  ;  in 
which  cise  either  one  or  the  other  iiiRtinct  mii.'ht  he 
pre>»'rve  '  hy  natural  Belectiori.  And  such  instances  of 
liiverMty  of  instinct  in  the  same  species  can  he  tihown 
to  occur  in  nature. 

Atrain  ris  in  the  case  of  corporeal  -tnicture,  and  ron- 
fortiiaS:  vith  my  theory,  tlie  instinct  of  each  'species  ;•. 
e<><vi  for  itnelf,  hut  has  never,  as  far  as  we  can  judir--, 
heen  jiroduced  for  the  exclusive  {rood  of  others.  ( >ne 
or  the  strontrest  nistances  of  an  animal  apparentlr 
performintr  an  action  for  the  sole  (food  of  another,  with 
whii  )i  I  ,im  acquainted,  is  that  of  apliides  voluiitariiv 
yield iti:r  their  sweet  excretion  to  ai-tH  :  that  tliey  do  so 
voluntarily,  the  followintr  facts  show.  1  removed  all 
the  ants  from  a  (jroup  of  ahout  a  d(»zen  aphides  on  a 
dock-ji!.int,  and  prevented  their  att<Midance  duririir 
several  liours.  After  this  interval,  I  felt  sure  that  the 
ajdrdes  would  want  to  excrete.  I  watched  them  for 
some  time  through  a  lens,  liut  not  one  excreted  ;  I  then 
tickled  and  stroked  them  with  a  hair  in  the  same 
maimer,  as  well  as  I  could,  as  the  ants  do  with  tlieir 
anteinia*  ;  hut  not  one  excreted.  Afterwards  I  allowtni 
an  ant  to  visit  them,  and  it  immediately  seemed.  i>v  its 
eajj'er  way  of  rumiin^f  ahout,  to  1m»  well  aware  what  a 
rich  flock  it  had  discovered  ;  it  then  iM-tran  to  play  with 
itj»  Antent!»>  riii  tlie  .iJidomeri  first  of  one  atihis  arid  then 
of  another  :  and  each  aphi*.  .as  booh  a.s  it  felt  the 
anteniue,  immediately  lifted  up  iUs  alnlomen  and 
excreted  a  limpid  diop  of  iweet  juice,  which  was  ea^rly 


I'JO 


ON    THE    OKKIIN    OF    S1'K(  IK> 


ilevoiired  hy  tin-  .i)if.  K.  in  the  (|uitt>  ymiii,'  .iphido* 
iK'li.ived  iu  this  m.iiiinT,  >hr»\virief  that  the  .utidn  wa.^ 
iiistiiH-tivp,  and  not  tlie  rosult  of  oxperitMii-t*.  H.jt  a- 
tho  <vx(-retiou  is  extremely  viscid,  it  is  proh.iMv  ;• 
t'oMveiiicnce  to  tlie  aiihi(lf>i  t«»  have  it  removt'd  ;  iinu 
therefore  jtrohal'lf  the  aj)iii<le«<  do  not  iiistitictively 
eA.rete  for  tlie  sole  eood  of  the  ants.  Althousjh  I  do 
not  believe  that  any  animal  in  the  world  perloriiH  an 
ai  tion  for  the  exrlnsive  tjood  of  another  of  a  rii.stinct 
Rpeeies,  yet  earli  si)eries  tries  to  Uike  advanta^^'e  of  the 
iii^tiiiets  of  oflier-:,  as  each  tikes  aiivant.wre  of  the 
waker  l»odily  structure  uf  others.  So  a^-ain.  in  some 
uw  cascM,  certain  inslincb<  cannot  ho  con-dered  aa 
aitsohitely  perfect,  hut  a.«  details  on  this  and  otner  such 
points  are  not  indi-per:-:'.hl.',  they  iriay  he  here  [ii.^sfd 
o,.-r. 

As  some  deirree  of  variation  in  instincts  nruier  a  state 
of  nature,  and  the  iniieritmco  of  such  variation-^,  are 
ii,.iis|)ensahle  for  tiie  action  of  natural  selection,  as 
iiiiny  inst.inees  as  possible  ouiflit  to  he  here  ^iven;  'out 
nant  of  space  prevents  me.  I  can  only  assert,  that 
instincts  certainly  d(»  vary  — f(tr  instmce,  the  miirratorv 
instinct,  Inith  in  extent  and  directiitn.  and  in  its  total 
loss.  i>o  it  is  with  tlio  nests  of  birds,  whicli  vary  partly 
in  depe.nlence  on  the  situations  cho-cn,  and  On  the 
nature  and  temperature  of  the  country  inhaliited,  hut 
uften  from  causes  wliolly  unknown  to  us  :  Audubon  has 
tfiven  s.-Noral  remarkalile  cases  of  ditfereuces  in  tiie 
ne-t.s  otthe  same  species  in  the  northern  atid  southern 
I'nited  States.  I'car  of  any  particular  enemy  is 
certainly  an  instinctive  (luality,  as  rnav  he  seen  in 
nestliiii,'  liinis,  thoiijfh  it  is  strent,'tlieiied  hy  experience, 
and  bv  tlie  sijr'it  of  fear  of  tiie  s.iine  enemy  in  «tther 
animals.  But  fear  of  man  is  slowlv  acijuired,  as  1 
l;ave  elsewhere  slutwn,  by  various  animals  inhaltitmg 
fesert  islands  ;  and  ^c  may  see  an  instance  of  this, 
eveti  in  Kuirland,  in  tlie  trreater  wildness  of  all  our 
larye  birds  tlian  of  our  small  birds  ;  for  the  larire  birds 
have  b.-.'u  nio-t  per.-ecuted  by  man.  We  may  safely 
ftttriluit-   the  ^rreater  wildness  of  our  larife  birds  to  this 


INSTINCT 


191 


.Mii-f  ;  for  in  uninh.iSiti'd  islarnls  larijp  hinl^  aro  not 
ii»(»r«>  ft-arful  than  muiII  ;  and  the  m.i-j)ie,  so  w.irv  ii, 
KiilM.ukI,  is  tame  in  Norway,  as  is  the  hooded  crow  in 
Kj-ypt. 

I  hattlie  ^T'THTal  (ii«|»(.s!tlun  of  individuals  of  tl-.-  ^,tm.' 
^;>f.it>s,ii.)rri  in  a  state  of  nature,  is  extromelT  div.rsiti.'d, 
(Mil  1)0  sh.iwn  hy  a  multitude  of  facts.  Sevor.ii  ci^cj 
aUo,  could  hefjiven,  of  ncra«ioiial  and  strarii^e  liaMts  in 
..Tt.iin  species,  which  niiifht,  if  advanUircous  to  the 
-p-.if"!,  ^ive  rise,  throuirh  natunil  selection,  to  quite 
ri'Nr  instincts.  l{ut  I  am  well  aware  that  tii.-^e  ir'Mieral 
-t.ifement-,  without  fact,s  j:i;cn  in  detail,  <-an  produce 
!.ut  a  t.M-i.Je  effect  on  the  reader's  min.l.  I  can  only 
rcp.at  my  assurance,  that  I  do  not  speak  without  ^ood 
t'\  idi'uce. 

Ihi'    possiliility.   or    even    pndtahihtv,    or    inherit«'d 
v.in.itiniis    of    instinct    in  a    state    of'iiature  will     ],v 
-trciiirtlu.tied  hy  hric/ly  consideririir  a  few  cases  under 
dt.mc-tication.      We  >t'iall  tlius  also  l>e  enahlcd   to  se*« 
the  respective  parts  which  hahit  and  the  selection  of  so- 
called  a.cidental   variations  have  played   in  modifyin-; 
•  fie  mental  (jualities  of  our  domestic  animals.    .\  numlK'r 
of  curious  and  authentic  instances  could  he  jriven  of  the 
in)  eritaiice  of  all  shades  of  disposition  and  tistes,  and 
i  Kewise  ot   the  oddest  tricks,  as.sociated   with  certain 
frames  of  mind  or  periods  of  time.      Hut  let  us  look  to 
thi    familiar  case  of   the    several    hreeds  of  do^'s  :     it 
cannot  he  douhted  that  yoiinir  pointers  (I  have  mvself 
seen  a  strikinif  instance)  will  -ometimes  point  ami  eveu 
hi(  k  other  d«»tfs  the  very  first  time  that  they  are  taken 
"tit  ;   retrieving  is  certainly  in  some  dejrree  iiilieritcf!  by 
-e'rievers  ;  and  a  tenden.'y  to  run  rou!id,  in-^tead  ot  at, 
a  ilo.  k  of  sheep,  hy  shepherd-do^s.      I   cannot  see  that 
th-M>    actions,   performed   without    e.\perien<e    hy  the 
vi>!jri:r,   uid    in   nearly  the   same  manner  hy  eacli' indi- 
vidual, performed  with  e;urer  deli<fht  hy  eacji  i.reed,  .-.nd 
»vitl.(eif  the  end  heinj?  known,  — for  the  vouni.'   ■•'..'•'.'■•er 
can   no  more   know  that  he  points  to  aid   his   master, 
'han  the  .vhite   huttertly  knows  why  she  lays  her  e^-if« 
on   the  leif  of  t)ie  cahhatre,— i   cannot   se«  that  these 


i 


i 


m 

m 


£ 


^:^A?^i 


192  ON   THE    ORKilN   OF    FPECIES 

.trtioii"  differ  ossentiallv  from  trti»>  iiistinct.«.  If  we 
were  to  «pe  oiie  kind  of  wolf,  wIumi  yum.ur  and  without 
iiiv  tniiiiiiitr,  a.«  -^'op  n>  it  sr«Mit»>d  its  prny,  st:iiid 
rr>(.ti(.rile-.v.  T  k.'  a  --tat'j.-,  and  then -lo-.*ly  crawl  forward 
H-itl,  ,1  |,.Tuli;ir  un.t  ;  and  aiiotluT  kind  of  wolt  ru^liimr 
ro.iM.i.  ni<tra.i  oi  at.  a  h.-rd  of  d.-.-r.  and  drivinc  tli.-m 
U>  a  distant  ].- ;it.  wt- >lioiiId  as-urcdly  .all  thoj'f  a.'lion^^ 
in-^tiii.tivH.  I>'.i.i.-.tic  in^tln;•t.s  as  t'hoy  may  b*>  .all.'d, 
arp  (•♦•rtainlv  1  vr  less  fixed  or  iiivari;iliK-  tlian  natural 
in,tin(t,s  ;  luit  tli'<v  have  l...'n  act-  ,1  uii  t.v  tar  Ifss 
rii.'ornii-  scl.Mtion.'and  !iav.'  h.-cn  trinMoitt-d  tor  an 
incnmi'aral>!v  shorter  i.tTiod,  uinler  Irss  fix.d  rondmonH 

of  lift'.  ...  1     ,  ■,  1 

Hmw   ■^•rMn_'-ly   th<'>i»'   di)mtwtic   in>tinftx,  tial)il-,  an»i 
di-M.-  t  o  1-    art'    iiili«'rit"d,    and     liow    rnrioiisly    tli«*y 
\>rrnuM'  iiiMi-l.-d.is  w.'i!  -'howii  u  lifn  diir.-rtMil  l.rtH-ds  of 
dn;rN  ar.'  .To-.Mi.      TliM-^  it  is  knovMi  lliat  a  rro^s  with 
a  tpill-(l'(L'  l!a---a*f.M-t.'d  for  rii.iiiy  trcnt'rations  th,"  roiira>r<-' 
and  ol,-t~ia<-v  of  -rrc.  iiOUTi  li  ;'  and  a  cnws  witli  a  crt-y- 
ho'ind  has  LMvi-n  to  a  wliule  family  of  >l,.>idiiTd-.ioir^  a 
t.Mid.-n.-y    to    liunt    liari's.        I'Iu-m'  dom.'.<tic    ui^tni.t^, 
«-ii.'n  Ihiistest.'d  l,v'Tii-.o,iiir,r('<.'mld.;  natural  mslinrls, 
\v!);.li    in    a    like  "ni  iiuuT    h.-ronu'    curiously    blended 
u>  ^'thor,  and    lor  a    Ioiil'   i..Tiod   exhihit  tracps  of  the 
iiiHtim-t-sofr    'lerpan-nt:  for  exami-U',  Ia-  Hoy  drMTil-os 
;i  .lo;,'.  wlio-o  irreat-irrandfalhor  was  a  wolt,  and  this  .lo^' 
sho^ri'd  a  tra.o  of  it.s  wild  j.;.rtMiti;rtM>nly  in  one  wav,  by 
iio^  .•omiiiiT  in  a  -trai-ht  line  to  bis  master  when  callwl 
I  'ome,f  ic  instini'ts  are  sometiine>  spoken  of  a>  action-- 
which  havo  become  inherited  sohdv  from  lontJ-continue<l 
and  c  .mnulsorv  habit,   but  this,  I   thiik,   is  not  true. 
N'o    (,„e    would    ever    have    thoutrht    ot     teaclnnir,    or 
nrohahly    could    have   tinit'ht,    the    tumbler-i.i>,'eon    to 
tumble  -an  a.tion  wln.ii.  as  I   have  witnessed,  is  per- 
formed by  vounur  birds,  that  havo  never  seen  a  ^)iireoii 
tumble.    '\Vo  may  believe  that  some  one  pitreou  siiowed 
a   -li::!it   tondencv  to  this  stramre  habit,  aii<i  that  the 
lotitccontinued   selection    of  tiie  be>L    indiv;du<ii:^    in 
pucces.ive  trenerations  made  tumblers  what   they  now 
are  •  and  near  (Jla-vow  there  aro  house-tumblers,  as  I 


INSTINCT 


199 


hoar  from  Mr.   Brent,  whirh  i-aniiot  (iy  eitrhtccri  incliea 
hiirli  without  t'oiiiu'  li.-.i.!  ovt-r  ht-rU.     I't  may  U-  (luiil)tt'd 
wht'thiT  any  om-  would  liave  thought  nftr-iiniiiir  a  ilojr  to 
point,  liail  not  M)mf  I'ne  doy  naturally  -hmvn  a  tcn.it'nfy 
in  this  lin»' ;  and  this  in  known  orca^iunally  to  lianin'ri 
.1^   I   once  S.-IM   in  a  j.uro  terrier:   tin- a.  t  oV  |Miiiitinir  js 
[irohahly,  a>  man)  h.i'c  thoutrht,  o?ily  th<-  e.\au:rerate«l 
[Mii^e  of  an  animal    preparintr   to  >jirin;r  on    its  iirev. 
U  iim  the  tir^-t  tiiuleiK  y  to  point  was  orite  displayed, 
metl,od:c.il  M-lectinn  and   the   inherited  effects  t,i  ('urn- 
puUory   training   in   each  successive  freneratmn  «.iuld 
-oun  complete  the  work  ;     and  uncon>cious  >election  is 
-till  at    wnrk,   as   eadi  man   tries    tu  pro<-ure,  without 
iiitcn.iin:;  u.  impnnc  the  hreed, doirs  which  will  stand 
.ind    hunt    l.cst.      On    the   other  liand,    hahit    alone   in 
some  cases  has  surtice<l ;   no  animal   i>  more  diUicult  to 
tame  tlian  tiie  yoinijr  of  the  wild  raid.it;  scarcely  an\ 
animal   is   tamer    tiian    the  yi^nui:  of  the  tame   r.Vl.bit'; 
!iut    I   do  not  suppose  that  domesi.;-  rahl.it-   have  ever 
i.e.n    selected    for    tameness  ;  ;,nd    1    |.r(-ume   that   w,- 
mu-f  attnhute  the  whole  of  the   inlierited  chaiiire  from 
extreme  wildnesti  t(t  e.\treme  tameness,  simply  to  hahit 
and  loiiL'-continued  close  confinement. 

•N'atural  instincts  are  lost  under  domestication:  a 
n-niarkahle  iu-taiice  of  this  is  se«-n  in  tho>e  hreeds  of 
t'.^U  which  very  rarely  or  never  hecome  '  hroody,' 
that  is,  never  wish  to  sit  on  their  eiTirs.  Familiari'tv 
alone  prevenU  our  seeinir  liow  u!ii\  ers.allv  and  lar-ielV 
the  minds  (»f  our  domestic  animals  iiave  l'.een  moduied 
I'y  d<.mesti<ation.  It  is  scarcely  possihle  to  douht  that 
th.-  Im\,.  of  man  has  hecoine  instinctive  in  tlie  dofj.  All 
wol\  es.  foxes,  jackals,  and  species  of  the  cat  -eiius.  when 
kept  tame,  are  mo^t  eatfer  to  attack  poultrv.  -heep,  and 
piu- ;  .ind  this  tendency  has  heen  found 'incurald.-  in 
d..j-s  which  have  heen  hrouL-'lit  home  ;t>  puppies  from 
'•••iintries,such  a-  'i'lerra  del  i-ur-o  an<J  Australia,  wliero 

the  savaiTi-s  do  not  ke=.p  t}-.^.-  ,^,,,^^^.^,\,,  a;:i:;;;.I-.  How 
rarely,  on  the  other  hand,  do  our  civilised  d(.irs,  even 
«iien  .|uite  yountr.  re.piire  to  he  tau-ht  not  to  att^Hck 
poultry,  sheep,  and  pi^'s  !      No  douht  thtv  ot-casionally 


.,r:^rz^''' 


194  ON   THK    ORKJIN    OF   SI»K(IKS 


<lo  makf  ail  attack,  and  ;in'  tin  n  Jicatfii  ;  ;iti(|  if  not 
curtMl.  tlx'v  aro  <lo<;t  royt'il  ;  «o  that  li.iSit,  witii  somo 
dfLTc*' of  sclfctiriii,  lias  prulrii.iv '■((!H 'irrcil  in  civilising; 
by  iiili«'ritaiicf'  oiir  (lo;/>.  <  *n  the  ntlicr  liaiid,  voutiij 
cliiclxcii-  Iriv  c  iost.  \\liii!l\'  hy  lialut .  fliat  f»'ar  of  tlio  do:; 
and  cat  \\h:ch  no  dnul>t  «as  (iriirij'-illv  in>-tinrli\(»  in 
liu'tn.  in  tin-  same  wa\'  as  it  is  »(»  |ilaini\'  iii-'i!!c*i\-f  in 
yoiiiiL''  jilica-.i!/-.  Mn'Mi.'^h  ri'and  iihdtT  a  'icn.  it  is  iirtt 
that  chi''l\<'n^  lia\c  ln»t  nil  toar,  hut  ft-ar  niilv  of  doL's 
and  cat^.  for  if  tlic  ht-n  i;i\<'»s  tlii>  daiii:''r  (  Ii'ickli",  Mu'V 
\\i!i  r-ni  (nnrc  f-pc'ir'.lly  vhiiii^  tur'i'\-i  from  undor 
lior,  and  cuncfal  tht-rn--'  1\  c^  in  tin?  -urii'ijtidin:,'  irrass  or 
t)iicl,rt>;  and  thi~  i~  «".  idt'nti\-  done  t'nr  tfic  ui-tuicti'-'o 
[iiir[iii»i'  ot;il,'o«  inj;.  a-i  vvc  ^cc  m  w  '!d  :.'f>>iind-t>i:ii-..  their 
nii'tluT  !<•  tly  awa\-.  I'ut  tlii-  !i-iin>  t  retained  h\-  our 
eliicKeus  h;is  In  cnnio  u-^ele---  under  di'ine-tica'  iiei.  tnr  tlu' 
Tnotli>'r-hen  lia>  alnmst  l(,~t  h\'  di-i-e  the  power  ot  (liirht 

Hence,  we  may  cMiicIude.  that  domestic  instintts 
lia\e  heen  acijnireil  and  siatnral  instincts  ha^e  heen  lo<t 
partly  hy  hahit,  and  ]'i'  ly  hy  Tiian  >(dectin;  and 
accuiini!a*in_'^  •iurintr  succes>-i\e  t'c'icration^,  peculiar 
nieiital  liahi'.-  and  actions,  whi(di  at  t'r-t  "M.pe'red  from 
what  v\-e  inu--t  in  our  iirnor.fice  (m!1  an  ai cidiMit.  In 
-orne  ca<es  roriipMlsory  hahit  aio-ie  has  -iif'iced  to 
produce  sutdi  inherited  men'  il  idiai;::es  ;  in  oilier  cases 
roiiipiiUory  hihit  ha<  done  nothii-.r.  ami  all  has  heen 
the  result  of  se]e<-tion.  piir-ned  hrih  methoijicilh-  aiid 
unconsciously  ;  hut  ir  miwt  cases,  pro)iahl\-.  hahit  and 
seleclion  ha\e  acted   |M_ellier. 

N\  e  shall.  periia]>s,  hest  nn  h-r-'nid  lio'v  iji-t  nets  in  a 
stale  of  nature  have  hecoiiie  ni..ditied  i>v  -elc  tiin .  hy 
coM-ideriniT  a  fen  c  ises  |  wili  selec*  ouU  three,  ret  of 
the  sc'cra!  v^l!■cll  I  sli.i'!  ha\  e  lo  d  -■  !,-s  in  my  luture 
\\'>i'k.  nanitd\  ,  tlie  instinct  \vlii(li  h' ul-  the  i  uckoo  to 
lay  her  eL'':s  ni  other  hirds"  nests  ;  the  slave-makiris; 
instinct  of  certain  ant<  ;  and  the  comli-makiiiir  power  ot 

tlie   hi\e-h'.'e  ;    thi'se  tw'i  hittev   iiistiei'ts  h;i\  e  i''ene!">!lv. 

and  most  justlv.  heen  ranked  tiv  naturalists  as  the  most 
wttndertul  of  all  known  instincts. 

It    is  now  coinnionlv  admitted    that    the    more   im- 


INSTINCT 


196 


Di'diate  and  Mnal  raimo  of  ttio  nirkoo'<«  irmtinr*  is,  that 
■<lif  lay«  her  '•>rirs,  not  daily,  hut  at  intorval-J  of"  two  or 
t}irt'«'  davH  .   so  that,  it"  she  were  to  inakf    h»'r  own  tioxt 
and   -iit  on   licr  own  otfi;s,   thoso   first   laid  would   have 
to  he  lef>  for  somt'  tir7U!  unmcuhatcd.  or  liu'n*  wmiM  h*" 
•■rtrs  and  yonnL'  hirds  ot' dificront  airt's  in  tli»<  -aTnenftst 
It  tills  w(T«'  tilt' .as*',  thfi  nroccs.-  of  layiriL'arul  hatriiitij; 
nn^'-ht  ho  incoiivtMiiciitjy   ion;:,  inoro  t-fit'i'MJlv  a-  sh«* 
has   to  niiirrate  at  a  ver\    parly   period  ;    and   Mm^  tir«t 
hitched  yonntr   .vould   j)rohai)lv  have  to   he  fed    hy  the 
male    alone.        Hut    the    Ainencaii    nickon    is    in'  'his 
nrediriment  ;   for  she  makes  her  own  ne<.t  and  has  etru'" 
md   yoiitiL'  s^^(■|■e^slvoly   hatclied,  all  at     he  -ame  tirno. 
It    has   heen   asserterl     that    the    Amen. an   ruckoo  oe- 
casioiially  lays    her   Oirtrs   in   otlier    hirc|<    ne^t^  ;    |„]t   1 
hear  on  the  hiirh  authority  of    1  >r.   I'.rewer.  that    'hisJH 
a  mistake.     Nevertheless,  I  eould  yive  ^.ev.'ral  instances 
i»t  various  idrds  uhnii  liave  heen  known  oecasiojialiv  to 
lay  their  ejji-irs  ;n  other  hirds'  ne^ts.     Nuw  jet  ns  supposo 
that    the   aneient    protreuitor  of  our    Kuroj.e;.n  (•'ickn<, 
liad    the   hahit<<    of    the    American    (  uckoo  ;     hut    that 
"cca-ionally   slie   laid    an   e^^t:   in   another    t.ird  -   ne^t. 
It    the  (dd    lurd    profited    hy   this   (na-asional    hahit.   or 
f  t!ie  you ntr  wore  made  more  vitroroijs    f.^■   ad^antaire 
'lavint:  heen  taketi  of  the  nii>taken  maternal  instinct  of 
■mother   hird,   than    hy  their    own    mother's  care,  en- 
.   inhered  as  ^he  can  hardlv  fail  to  he  hy  ha\  inu"-  e^-'irs 
iM'i  younir  of"  different  a^'es  at  the  winiotime  ;  then  the 
Old     hirds    or    the    ftwlered   youiiir    would   train  an   ad- 
■>anta:.'e.      And  analoiry  would   lead  me  to  hel:eve,  that 
'h.'    voijTif    thus    reannl    would    I'O    a[.t    to   toilt.w   hy 
nheritancp  the  occasional  and  alierrant  hahit  of  their 
'iKjtiirr,  and  in  tlieir  turn  would  1)0  apt  to  lav  t  !:c:r  ei'-rn 
in  other  iiirds'  nests,  and  thus  he  successful  in  n  ann>f 
t!K'ir  youiiix.       l>y  a  continued  proc»'>s  of  this  nature,  I 
I'elieve  tiiat  tlie  stran-e  instinct  of  our  cuekoo  could  he. 

and       ll.'K      liixitl        trti, ,,,,-■,*,, A  I       r>. I.I       ll    ..1        „    .  .1:.     _ 

to  i  >r.  (iray  and  to  some  otlier  oh-cr\er>.  the  l-.urope<an 
cuckoo  has  not  utterly  lost  ail  m.iternal  luve  and  i-are 
for  her  own  offspruig." 


1J>6 


ON   THE   ORIGIN  Ol     sl'iK  IKS 


'Hie  orcasional  hahit  of  hirds  layiiiff  their  eetfs  in 
otlicr  l»inls'  nests,  either  of  the  same  or  of  a  (iistiiut 
specu'-t.  is  not  very  iiiicoriiiiHui  with  the  iialliiiaceie  ; 
anil  this  perlianx  explains  the  onirin  of  a  sinjfular 
iiistiiK  1  in  the  allieil  trmup  of  o>trn  hes.  F<»r  neveral 
lien  o-itrii  lie-;,  at  h'a^t  in  tlie  ia<e  of  the  Arneriran 
sjiecies,  iirnlf'  au'l  lay  ti^^t  a  few  et,'i:-  in  one  ne>t  and 
tlieii  in  another  ;  ami  tlie-ie  are  hati  lied  hy  the  males. 
'Hiis  ui«':nr!  rii.i\'  |irof>.il>lv  Ixi  arcounteil  lor  hy  tho 
fact  of  tlie  hens  la\  wiiT  a  lar^'O  niunlier  of  ej-i^s  ;  hut, 
."is  in  the  <a-e  ol  the  nitkoo,  at  inter\al»  of  ^wi,  ur  three 
(lays.  Thi-  in«tirii't,  howescr,  of  the  Arneriran  o-trirh 
tia-  not  as  ytt  I.een  perfected  ;  for  a  surpri^iui:  fiumher 
of  e:.''j;'«  lii'  str«'v*«'il  over  tlie  plai.i>.  so  tiiat  in  one  day's 
hiintini,'  I  pu;ked  iiji  no  less  than  twenty  lost  and  waited 
etftfs. 

Manv  lK»es  are  para>itic.  atui  alwa'.'"  lay  their  e:ri:s  in 
tlio  n.'sfs  of  liee'4  <it  other  kinds.  1  his  case  is  more  re- 
niarkahle  than  thai  of  the  cuckoo;  for  these  hees  have 
uot  only  llicir  instincts  hut  their  structure  moiiifird  in 
accordance  xvith  their  jtara^ilic  lial>;ts  ;  for  they  d-t  iiitt 
possess  the  {lollen-ctdlectinir  apparatus  which  would  ho 
neressarv  if  they  had  to  store  food  for  their  <i\»n  vonn;;. 
Some  species,  lik»'wise,  (»f  Spheijidie  (wa-ji-like  in>ects) 
are  parasitic  on  other  spci-ies  ;  and  .M.  I  aine  h^is  lately 
sho"  n  iTood  reason  for  iK'liexini;  that  aithcniirh  tho 
lachytes  niLTa  jrenerally  makes  its  own  hurrow  ai<'l 
stores  it  with  paralysed  prey  for  its  own  lar\a»  to  feed 
on,  yet  that  wlicn  this  insect  tinds  a  harrow  already 
made  and  .stored  hy  anitther  splie.x,  it  takes  advant;ufe 
of  the  prize,  and  i.ecoines  for  the  occasion  jiarasitic.  lu 
this  c;ise,  as  uith  the  suppiised  case  of  the  cuckoo,  1  can 
see  no  difhculty  in  natural  seh'ctioti  making'  ati  occa- 
sional hahil  permanent,  if  of  advanta;_'-e  to  the  species, 
and  if  the  in>ect  who»e  nest  and  stored  food  are  thus 
fehtniously  approjtriated,  he  not  thus  exterminated. 

Sltive-rtinking  inxtinrt. —  This  remarkahle  instinct  was 
first  discovered  in  the  Formica  (I'olyertres)  rufesceus  hy 
Pierre  Hiiber,  a  In'tter  observer  even  than  his  celebrated 


m 


INMlNcl 


1»7 


1 


fatlior.  'ITiis  ant  ig  sVisolutcIy  dependent  on  its  slaves  ; 
without  their  aid,  tlie  species  would  certainly  f>e- 
come  extinct  in  a  hin^fle  year.  'Hh'  males  and  fertile 
females  do  no  work.  The  worker^  or  sterile  feniaU-*, 
tlmiiifl;  most  eiierjfetie  and  couraireous  in  capturitij.' 
^I.l\es,  do  no  otlier  work.  I'hey  are  incajiahle  of  mak'nt; 
their  own  iirst.s,  or  of  feediiiir  tlieir  own  larv*.  \V  hen 
the  old  iiest  in  found  inconvenient,  and  they  have  to 
III  if  rate,  it  i.-i  the  slaves  whicli  determine  the  mijfral:on, 
and  a(tually  carry  their  m;ist«'rs  in  their  jaws.  So 
utterly  lu'Ipless  are  the  ma«ter«,  that  when  Holier  shut 
'iji  thirty  of  them  witljout  a  slave,  hut  with  pletity  of 
tde  fond  which  they  like  l>est  and  with  their  larva?  and 
pii|»ie  'o  stimulate  them  to  work,  they  did  notliinir  ;  they 
rrdild  not  e\en  tied  themselve.><,  ami  many  perished  of 
•  lunirer.  Muln-r  then  introducer!  a  siiit'Ie  slave  {V. 
tii<caj,  and  she  instantly  set  to  work,  fed  and  hiived  the 
-i.r\  Ivors;  made  some  cells  and  teudtd  the  larvip,  and 
jilt  all  to  ri::^lit«.  What  can  he  more  evtraordinarv 
tiiiii  tlu'se  w»'ll-ascertaine<i  lacts.-  If  we  had  not 
k::  iwn  of  any  otlier  slav»>-makin{;  ant,  it  would  ha  e 
Ihi!i  hop«'le-.s  to  have  sjteculated  how  so  wonderful  an 
in-tinct  could  have  been  perfected, 

.VtiotluT  .-pei:es,  Kormii'a  sanyuinea,  was  likew'se 
tir-t  discovered  hy  I'.  Huher  to  he  a  (ilave-makiiiir  ant. 
Ihis  '-pecies  is  found  in  tlio  .southern  parts  of  Knirlartd. 
i'.n\  its  iiahits  liave  iieen  attended  to  hy  .\fr.  J  .  >!i;ith, 
"'  tlie  llritish  Museum,  to  whom  1  am  mucli  imiebted 
tor  inforination  on  this  and  other  suhiects.  Althout:h 
fullv  tru^tiiur  to  the  stateiiiefit.s  of  Hut)er  and  Mr. 
>initr;.  I  tri<'d  to  approach  the  suhject  in  a  ■weptical 
fraiiie  of  mind,  as  any  on'-  mav  well  he  excused  for 
'iouiitinjf  the  truth  of  so  extraordinary  and  odious  an 
:i-tiiul  as  tliat  of  makiinf  ^ia\es.  Hence  i  will  jfive 
•he  oh-ervalions  which  I  ha'.e  myself  mrole,  in  sonie 
':tth'  detail.  J  opened  fourteen  nest,s  of  F.  -arnfuiu'a, 
I'iil  toiin(i  a  fi,''w  slave*^  in  hII.  Males  and  fertile 
ri males  of  the  slave-specie.*  (F.  fusca)  are  found  on'y  in 
'h*  ir  own  proper  commu'iitie-,  and  have  ne\er  been 
ol-ervt-d  in  tlie  nestH  of  F.   -.uiiruinea.      Hie  slaves  are 


m 

til 


im 


ON   TUK   ORUilN   OF   SI»E(  Ih> 


s^^.i 


Mark  Jiiul  not  atiovH  lialf  the  si/«  nt  tlifir  ro<l  masters, 
HO  that  ilie  Kiiitra.'^t  in  tlu'ir  ajiprannct'  is  \«Ty  ^'reat. 
Wht^ii  tlu'  in'st  iM  hliirhtly  liii^lurtted ,  tlip  slavi'H  orru- 
Hioii.tllv  «iim(>  out,  niid  like  thuir  ma«it<'rH  ar««  nim-h 
aK''''»''l  and  di'tcnd  tim  in-st  :  uhcii  rli<«  iip^t  is  mucli 
ili«tiir!«;'d  and  tiji'  larv*  ami  puji^  arc  <'\|>iis(.(l,  fho 
«la\»'s  \T(irk  ♦'ufi-L.-fM  ally  with  their  tiia-tfrs  in  carryirnf 
tln'iM  aw, IV  tu  a  jda.c  ot  s.iloty.  llcnri-.  it  is  «lcar,  that 
the  slavf.  trvl  <|uite  at  lium*'.  Duriii,'  the  riiKutlH  of 
.iujM-aiid  ./illy,  t>a  tjiree  Hiicces'-'ive  year-.  I  have  watched 
fur  many  hours  neveral  ncst.x  lu  Surrey  aim  >u^«iex,  and 
uever  saw  a  slave  eiili.-r  leave  or  enter  a  ne-t.  A.x, 
'lurm^  these  montlis,  tlie  sla.es are  very  few  in  nufiiher, 
1  thoiiulit  that  ttiey  Miitrlit  helia.e  dilterenily  w  h»Mi 
(iiore  nimp'MiiH  ;  hut  Mr.  Smith  informs  ine  that  li«'  han 
i*atilie<l  i.iie  nt'>.ts  at  various  hours  diirinjr  .May,  J  .lO 
and  .\utrusl.  'Mitii  m  ""urrey  a;i<l  llaiii).-(iire,  an<l  ha.s 
never  seen  tiie  ^la^es,  thout;Ii  pre-ent  in  larue  nunih«Ts 
in  Auu^usl,  «-ither  l<'a\f  or  enter  thf  ne^t.  Henee  he 
considers  tjir-n  as  strictly  h«Mi«.«'hol(i  Hlaves.  I  he 
mast<Ts,  on  the  other  lianii.  may  ite  <onstantly  seen 
hriiiuiiii^-  in  n.aterials  for  the  ne^t,  and  fo(.<l  of  all 
kinil>.  i)iirint.'  the  present  year,  however,  m  the 
month  of  Jiily,  J  came  across  a  lornmunity  with  an 
unusually  ]ar;;e  sto.  k  ol  slaves,  ami  I  ol.-cr\ed  a  tew 
blav.  --  iriiny-le<l  with  tiit-r  nia.stur»  loavuiLT  tin'  uc-.t,  an<i 
mai.  in  m  niov)/  the  Name  r(K»tl  to  a  tall  Sc(.t.  ii  lir  iree, 
twenty-iue  yards  disuml,  which  they  ascended  to- 
ifother,  pr'i'>ahly  iu  se.'jrt  h  of  apimles  or  cocci.  .Ac- 
corduiK  to  lluher,  who  had  amide  opportunitie.s  lur 
obberyation,  in  Switzerland  the  slaves  h'ahitually  wnrk 
with  their  iiias',fr>  in  niatcinL'  tiie  nest,  and  thev  alone 
open  and  clo-..'  the  doors  in  the  njornini:  an!  e\enin^'' ; 
ami,  as  lluiK:!  r\pre---ly  Htate«,  their  j.nmi[»al  oifice  is 
to  --e.irch  for  .iphidcs.  'i'liis  ditference  in  the  usual 
hahits  of  the  masters  and  slave-s  in  the  two  tountrii-s, 
prohaidy  de|>ends  inerclv  on  the  .slaves  beinj.:  cantiired 
iu  jfreater  nuini»ers  in  Swity.erland  than  in  Kiiirland. 

t>noday   1    fortunately   witiuvssed   a   mipratiou  of  F. 
sanruine.i  from  one  uest  to  auotherj  and  it  wa«  a  most 


fe-1 


INSTINCT 


lOli 


iiiT»«rPstin<f  spert.iflo  to   U'hnld    tlic   mn^tprs   rarofully 

t  a:  ryiii;;  (iii«u  .1(1  uMM'iiik'' (".•irrifil  l>y.  as  in  \\\i-  <m-«»  <if 
'  riifesriMiH^  tlu'ir  •'In  fs  ill  tlieir  jaw^.  Aimrlii-r  (l:iy 
:.\  attf-iitioii  wa■.^lrul•k  liy  ahout  a  -coro  ot  tin* -l.ivi»- 
:  .  iki'iH  daiitititiL'  till'  s;iine  -[.ot.am!  csiiirntlv  iiol  it) 
searcli  (»t  f(H)(l  ;  tlioy  a[>jir«iarlM'il  a:iil  \vt>rt'  v  i:.'nriiu*ly 
r»'jiiilse«l  i'v  an  iiiii»'|>«Mi(lciit  ciiiiiniuuity  i>t'  tin-  »laM'- 
sjH'i'ies  (F.  lU'ca'  ;  miiik  ..mt-^  a>  inan\  a-.  l!iri»«'  of  tln-^e 
aitt,«»  cliii^''tnir  I"  ili<-  IcL's  of  ih.'  -1 IV  <»-m:il\i;ii.'  I'.  *sni- 
^•iiitioa.  Tii*'  lattiT  riitlili'silv  killcil  tln-ir  »;iiall  oj>- 
poiitMiN.  and  <arrit'<i  tlifir  dt'ati  ImmIjw  .is  (<mh1  to  th»*.: 
n.'st.  t  .*oiity-miie  yanl-  (ii«taiil  ;  luit  liny  acn*  |m»>- 
\fiiU'ii  iritm  LM'ttiiii^  aiis-  |>ii|i;flo  r»'ar  ai  slau--.  I  then 
tliii;  ii|i  a  -inal;  panel  of  Mn*  |iiip.c  ol  I.  fii-^'a  from  aii- 
o'luT  rii'-t,  .mil  |iut  tiiffti  (liivvii  on  a  Imiv  -i>«tt  iit'ar  ♦))»• 
iihii  I'  of  roiiiiiii  ;  tln-v  were  ra^'iTU'  ••fi/»>(l,  and  <'.irri('<i 
olF  I'V  tin*  tyrant  .  «li()  j't'rh.ijc  raiirit-il  tliat,  at\fr  ill. 
liu'v  had  hi'tMi  \  u'turioii-  in  thi'ir  lato  coinlial. 

At  tiic  <ini  •  tiiiK'  I  laid  on  the  same  jdai-*'  a  «imail 
[iar>  I'l  of  the  |)iiji;»'  of  an«tt!nT  mju'iIps,  K  tl.iva,  vsith  a 
f>'\\  of  these  JMtle  yt-llow  ants  ^tiIl  fliii.'iiic  to  the  fnitf- 
i  ;rn'«.  of  the  nest  I  iiis  speeies  is  .^onii-times.  thmnrh 
'•i'"i'i\-,  rnailo  into -!aM--,  as  ha*  heeii  de-<cri''e(l  t.y  Mr. 
."^i.i.'h.  Althoiitrii  so  siiKill  a  spcnes,  il  is  very  lour- 
au'MMiSj  and  1  iiav««  •-e<Mi  it  fer(»eiou-ly  attack  other  ants. 
ill  I'liO  iii-tanee  1  found  tu  my  surprise  an  indepeiident 
lommnni'v  of  K.  Ihaa  iKiiier  a  sto.-ie  heneath  :i  ncst  of 


J; 


deiiUUy  disturhod  hotli  Hitst^,  the  little  atits   af.i>  ke« 
♦i:-'ir  hi^  neiirli'Miiir.s  with  s>,-j,ri-ini?-  «*oura.'(«.       .Now  , 


tilt?  slave-'iakinu  F.  satitruinea  ;  and  when   I   h.id  aeei- 

•d 
I 
-  lurious  to  asiortaiM  whether  F.  santrmn»»a  <oiild 
liisiiiimiish  the  pupa'  of  F.  fii-ra.  wlii 'h  they  hi!''; 'lally 
make  in'o  slaves,  from  those  <»l  the  little  and  h.iiims  !■■. 
t' vva,  which  they  rarely  <a]it(ire,  and  if  v\a.s  evidejit 
•'  ''  t' f\  did  at  once  distniirui-h  thi'iii  :  for  we  lia\e 
r  en  that  tliey  eairerly  and  in-Liiiitly  seized  the  pup;**  of 
t.  lusra,  \vh»*rt>a.s  thev  were  much  terriiied  when  the\ 
came  across  tin  pi:p*,  or  e\'>n  the  earth  from  the  nest 
of  F.  flava,  and  quickly  rau  away  ;  hut  in  ahout  a 
•quarter  of  an  hour,  shortly  after  all  the  little  yellow 


Hit 


n 


200 


ON   THK   ()RF(;iN   OK  SPECIES 


I 


arifx  li.iil   <T.-i\vh'il  .iway,  they    took    heart  and  rarrie*! 

off  tllC   Jll||»>»*. 

( )rie  ineiiiii;/  I  v  i-iltd  another  <(»uiniiinity  of  K.  <«u- 
iT'iiiiea,  atiil  toiiiid  a  iiurnher  of  th('-.e  aiil><  returiii!!^ 
hoiiif  and  eiit<-riiiir  tln-ir  in-t«,  carryn;;  the  dead  Kodi""* 
of  K.  (ii^i-a  (•.hov\  ill;.'  that  it  wa.x  iiot  a  aiiif ration)  arui 
iiiimrruii.4  |iiii>;e.  I  trari'd  a  l<ni;f  hie  of  aiitx  hiirtheiieil 
willi  iioiify,  Iiir  ahoiit  tnrty  yards,  to  a  \ervth;rk  <liirn|i 
of  heath,  v*lii'tice  I  -av  the  hi-^t  indiu'lw.il  (if  K.  phu- 
iriiine;!  eiinTirt",  <arryiiiL'  a  pupa  :  Imt  I  ua^  not  ahle  m 
tiid  tlif  (le-ulatfd  iie>.t  in  Mie  thii  k  htatli.  Ilie  nc-t, 
howf^iT.  inii-t  ha'.e  h»'en  ehxe  at  h.ind,  fur  two  'ir 
thrt'"'  imliv  iduaU  of  I',  tii-ra  were  rii-ini.c  ahoiit  ni  t)ie 
crealeNi  .itritafiori,  and  one  wa«  jM-rched  iriotioiih'^-  .v;*ii 
it*  iiwn  pupa  iti  iLs  rmnjt  h  on  tlio  'op  of  a  '■prav  of  heath, 
an  iiii  ci'e  (it  de-pair,  over  its  ra\aLre(i  home. 

N'i(  h  are  thi-  t.icts,  thoii::li  thev  'iid  not  need  con- 
firrn.ition  hy  nie.  in  reiT'ird  to  the  udndcrful  instinct  of 
iiiakiritr  sla\t>-.  I>'t  it  he  oKser\-ed  \v)iat  a  cdntrit-t  tlie 
instinctive  liahits  of  \-'.  s,iiiiruiii,.;i  present  wit!i  those  of 
the  ci.ntnient.il  K.  riifescci  s.  The  hitler  does  not  huihi 
its  o'Aii  lies!,  dues  nut  determine  its  own  micralions. 
i|ii('-<  nut  coiicc;  i.iod  for  ;t>elf  or  its  yoini;.'',  .iiid  (.iiiuot 
e\tMi  feed  it-cif;  it  is  ahsolntely  dependent  on  its 
iiiiTiieidiis  -l.tx,.^.  I'oriniea  s.ini;iiinea,  on  th  •  other 
liaii'!,  pn>.v,>v.(.^  much  fc\N('r  •"laves,  and  in  the  early 
part  (it  the  summer  extrcmeh  few  :  tiie  ma>ters  deter- 
riiMie  \\]f]\  and  wliere  a  new  ne.st  -hall  he  formed,  and 
when  tliey  mi:.'-ratf.  Mio  m.i^ters  cirrvtlie  >lave-i.  HoMi 
in  Switzerland  and  IJiLrland  tlio  -la\es  -cimm  t(i  ha\o 
the  exclusive  care  of  tlie  lar\.e.  and  tlie  masters  alone 
•Xi^  on  •.j.ive-makinir  expeditions.  iti  >»;t/.crland  tiie 
slaves  and  ma-?cr>  work  tdtretlier,  ni.ikii./  and  hriiiijin;; 
materials  fnr  tlic  ne^t :  Iiotli,  hut  chieliv  the  >laves,  teiul, 
and  milk  as  it  m,iv  he  calleil,  their  aplmic- ;  and  ihu.s 
lifitli  colle('t  food  fur  the  community.  Iti  Knirland  the 
!oa>ters  ahme  u-u.illv  leave  the  nest  to  collect  huildini; 
fiiatcriais.iiHJ  ioo(i  for  I  ii  em -fives,  tiieir  slaves  ;inii  iarv  w. 
So  that  the  m.i-ters  in  this  country  receive  nuich  !e<»« 
service  from  their  -slave«  thati  tliey  d«»  in  Switzerland. 


IN>I  IN<  T 


201 


Bv  what  nicy*  th»'  iii-timt  ot  F.  •wiinfuiiiea  oritriii.ite<l 
I  will  not  preU'tifl  to  roiijertiire  lint  ax  ;uit-,  which 
irr  'lot  il^vcv-niakprx,  will,  a«  I  li:i\  c  mn-ii,  carry  orf 
liii|i»»  of  otli«»r  •i|>«'(i»"*,  if  xcatt^'HMl  ru'ar  tlu'ir  iirst-,  it 
M  |»o»j*iliU»  tliat  ■•Mcli  ]tu]>if  nriifiiia'.ly  sturiMl  iw  tiimi 
mikrht  IxM'onift  d«ni'I(i|M^il  ;  ami  the  fun-icn  ants  tlni«* 
uiiinteTition  tliy  reare<l  wouhl  then  .'nll.r.v  tlii-ir  proper 
.U".tiiict.H,  ami  <lo  what  work  tlu'V  rouhl.  If  tht'ir 
liri'seiire  proved  useful  to  the  'iji»>«it's  whu  li  h;nl  •••i/»'<l 
•lu'm-  if  it  wi'TO  iiioro  advantatfrou-i  to  this  s|»rii»'s  to 
rittturB  workers  than  to  jinnreate  tliern  the  hahii  ot 
'  'ilectinj;  pup*  oriirMially  for  food  iniuiit  hy  natura' 
-rlertioii  ht  ^Vrt'iiL'thfMO*!  atnl  rendereil  pernianeiit  Tor 
tiio  very  ditferent  purjio^e  of  ni-^iiijf  slaves.  W  hfu  the 
iii-itinct  wai*  once  acijuired,  if  larried  out  to  a  nuirh 
If- exrerit  even  than  in  our  itritinh  I'.  s.uuriiioea,  which, 
I-  we  have  -^eci,  ii  less  aided  liy  it>i  »la\  es  than  the  s-itne 
«pe'ics  in  Swit/erland,  1  can  -lee  no  ilit'ii  t;lty  in  na'urai 
>.dectiou  increasintf  and  modifyinj;  the  insti-ict — alwayt* 
"Upposirij;  pacli  nioditicatioii  to  he  of  use  to  the  specie^ 

•iiitil  an  ant  vas  formed  aw  at>jectly  dependent  on  iU 
-la>cs  a.^  is  the  Formica  rufesceus. 

I'fll-innking  in*t\iirt  oj  tK»-  ihtr-Hrr.  —  i  will  not  hero 
•liter  on  minute  details  on  thiM  suhject,  hut  will  merely 
j-ve  an  outiine  of  the  con.dusion.s  at  which  I  have 
Arrived.  He  must  he  a  dull  man  who  can  examine  the 
exquisite  ntructure  of  a  comh,  -o  KeaulifuUy  »<i  ij>ted  to 
Its  end,  without  enthusia>tic  adtniration.  W  e  hear 
rVini  mathematicians  tliat  l>ees  have  practically  <oi^  ed 
I  recondite  pri.hlem.  and  have  made  their  cdls  of  the 
inHpcr  >lia{»e  to  holil  tlie  trre^itest  po>-sihle  amount  of 
liotifv,  with  the  lea^l  p«»s>i!de  consumptinti  of  precioui 
wax  in  their  con^tructuni.  !t  ha-  Iteen  remarkf'd  that 
a -kiltul  workman,  with  tiltir;.'  tools  and  measures 
would  tinil  it  very  difficult  to  make  ceils  of  wax  of  the 
true  fnrm,  thonuh  this  is  juTfectly  etfected  hy  a  i-mwd 
ot  hees  working  in  a  dark  hive.  (irant  whatever 
instincts  vou  please,  atjd  it  seems  at  first  .piite  incon- 
ceivalde  {low  thev  can   make  all  the  neceHSiiry  aujfles 


2(12 


ON   THE   ORIGIN    OF   SPECIES 


aii'l  planes,  or  oven  jK-neive  whoii  tiiey  are  corrtctly 
m;i(lo.  JWil  tlii>  iliilicully  is  not  nearly  ^■o  tfreat  as  ii  at 
fir->t  apjK-ar^  ;  ali  tlii«  [)»Mutifiil  work  can  l»e  shown. 
I  think,  to  foll'^Aiioina  luw  very  eiiiiojc  instiiici.-,. 

1  •vas  lf(l    to  invesiii.Mtf  this  siilijcrt  l)v  Mr.   ^\'at»'r- 
h().iM',  i\lio  has  .sliov*n  tliat   the  fonn  of  tlit' ceil  staml^ 
111  ilo-c  rcl.it. oil  to  ;lie  jirt's»>iit  i*  <tf  :ul;oiriiii;,'  ccis;  aiwi 
tho  following;  vitMT  may,  [(.'rhaps,  he  i  (tii-ul.Tcii  only  am 
a  iiiodifiialxoi  of'  h;.  tiicory.       I^-r  us-  jo.ik    to  tlie  tc'ri-al 
l>rirn'i|)!t.   .,;    m  i.iiUon,   and   ^cr   uheUu-r   Natii.-c  does 
not  reuMi  to  ui  iier  ni»'tho(i  uf  work.       \-  o.ie  fod  o?'  h 
b.'iort  scrie-  we  )ia\o  liu?iiMe-tM'e>,  HJii.ti    u^i-  the:rohl 
rocoons  to  lodd  honey,  -urneliinev  adding'  t<»  tlu'in  s'nort 
tiihe-^  ot   Ma\,  and   lik".\:M-    miikio:.'   -.-ii. irate  a;iit  \ery 
irre^^ular  nouKii-d   c-Ils  .,:'  wa.v.      At  the  other  end  of 
the  stiries  «.-  hav.    Lhe  .ells  ol  the  hi\t-''e!',  |.!;ii  d  in  a 
douhio    laxor:     e.udi    cell,    as    is    ucU  -  known,    is    .an 
ln'.\.it:onal   [oi-m,  wit),   tti..-   hasal  e-ltres  oj'  its  si.\  r-ules 
h«'v»'lh'd  so  ;..-  to  lit  oij   to  a   [lyramid,  formefi   ot  three 
rhoMihs.      'J'lio,--  rhoinh.s   h;i\i>  lertairi  an-les.  and   the 
tiiree  which  toi,ii  ihe  i-yrainidal  h.ise  of'a  sintrlc  ccH  on 
o!u>  side  oJ  tlie  com*',  enter  into  the  coniposition  ot  the 
li.ises  «d  thiet;  auium'ii;;  cells  oii   J'  e  oioiosite  side.      in 
the  ser.ox  in  tween    the  e.vtreine   |»erA'ciion  of  tiiectdls 
o,*    ti:e    hi.e-heti    aud    tlu-    siruidicity    ot    thi->c    „f   the 
hiiinhli -l.ee,  «f  ha\e  tile  cells  ot  the"  .Mexican  MiMjioria 
domwjLic^,  carefully  tlescn!>ed    and    tiuMuctl    h\    I'lerre 
Huber.     'J'he  Midijiona  it.self  in  iiiterniediate  in  struc- 
ture hetvTm-n  the  hive  and  liunible  iiee,  hut  tntoe  n'-arly 
ris'ated  to  the  latter:   it  lunns  a  nearly  regular  waxen 
cooih   of  cylindrical    cells,    in    which    the    youni^   are 
hatched,  and,  in  addition,  .some   lar;.'^e  cells  id"  w.i.x  for 
holdinir  honey.      1  hese  iatler  cells  are  nearly  spheruai 
ao.l  ut  nearly  cijual  .--izes,  and  are  a^'^^jrc^atcd   into  an 
iriciTular  Mias-i.      Mut   th(>   nnjiortaut   iioint  to  noti;'e,  i^ 
that    till  so    celN   are  always    made   at    that   de^rree   of 
nt-Hirne-s  to  e.icli  ntluT,  tli.it  they  would  have  intersected 
or  t)rokeo  into  each  other,  it"  the  spheres  had  heen  com- 
pleted ;  hut  thi^  IS  never  permitted,  the  In^es  building 
perfectly  flat  walls  of  wax  between  the  spheres  which 


bsiii^yiiiiiBii& 


INSTINCT 


2on 


'Jnis  tend  to  intersect,  fleiico  each  roll  consists  of  an 
•  iiitfT  spherical  jM)rtiou  and  of  two,  three,  or  more 
[)t'rtertly  Hat  Mirtaces,  according  as  tlie  o«'ll  .Kii'-nirf 
two,  lhnt,\  or  more  oihrr  d-ll.-.  When  one  cell  coniC!) 
iriio  contact  wiih  three-  ollicr  cell^,  *\hich,  from  tlie 
Vi.herc^  l)»'iriir  nearly  of  the  sanif  size,  is  very  frequently 
;i  .ii  nt'cer-^arily  the  case,  the  three  liat  .sur  .i<es  ar.- 
uiiiiea  itit(»  a  |»vr;imid  ;  and  tliis  pyranmi,  as  lliiber  lia- 
r-iiiarked,  is  iii:inik'>Hv  a  trross  imitation  of  the  thifc- 
s.aed  pyrainiihii  haesot  the  cell  ol  ttio  hiv«»-l)ee.  A* 
1!  the  ceils  ol  tiie  hi\e-b«H},  -o  here,  the  tliree  plane 
SI. Places  in  any  one  <ell  nccessiirily  enter  into  the 
ci  nstruction  ui  ti:ree  aiijui/iinif  cells.  It  is  «/nvioun 
tiiai  the  Melipona  skives  wax  hy  this  manner  of  I/Uililiiiff ; 
tir  th»»  Hat  w.'iils  hetween  the  adjoining  cells  are  t.nt 
iliiilth',  hut  are  of  the  same  thickness  as  the  outer 
s;  uerical  port:()ns,  ai.  i  yet  each  ihit  poition  forni>  a 
[)art  of  two  cells. 

llcHectiiitj  on  this  rase,  it  occurred  to  ine  th.ii  ii  t:ic 
.Mdipona  had  m;ide  it.s  sytheres  at  fcome  tfiveu  il, stance 
from  each  other,  and  liad  made  them  of  equal  sizes  and 
had  arrantred  them  symmetrically  iti  a  douhle  layer,  the 
roultiiii:  >tructure  would  proha'nly  iiau'  heen  as  [lerfcct 
a,  the  comh  of  the  hive-hee.  Accor<iiii^iy  I  wrote  to 
l'(nf.--.or  MiUer,  or  (  amhridire,  and  this  ;:eoim'er  has 
V  mllv  rea:i  o.er  the  follouini^  sLaU-n'Cuf,  di.ifii  up 
:  om  hi^  informadun,  and  tells  me  that  it  ia  .-Lrutly 
.urriH  t  :  — 

li  a  n.iml>er  oi  equal  splieres  he  descri!r^l  wiih  their 
ci  nircs  phii  t.-'i  in  two  [)ai;iiifl  layers;  «ilh  thu  li  ntid 
■  i  t  :u!j  -j'hero  at  the  disLanco  of  radius  x  ^'  2,  or 
:\niis  A  l-ill-l  (or  at  some  h-sser  distance),  frurii  the 
•xnlren  ot  the  si.x  surroundiim  .^phereti  in  the  .same 
hiyer  ;  and  al  the  same  distance  from  t!ie  centres  ul 
I'he  ad'oinini;  spheres  iii  the  other  arul  pa.-allol  layer; 
iht  u,  if  planes  (if  Miiersection  hetwefto  the  -e\ei<i! 
spliere.s  in  hoth  lavers  he  formed,  there  will  r-'sult  a 
d<»ut)ie  layer  of  he.xiuional  prisms  united  to^etlier  by 
pyramidal  l>ases  formed  ol  three  rhomhs  ;  and  the 
rhouilw  and  the  Hides  ot  the  h<  xa!;onal  prisri.r<  -tui  iia/e 


204 


ON  THE   ORIGIN   OK  SPPX  IKS 


every  nriL'le  identically  the  same  witli  tliel)est  measiire- 
montH  which  have  been  mude  uf  the  cells  of  th»* 
hive-hff. 

Hence  wp  may  safely  coiiclMfle  that  if  we  'ouM 
slicli'Iv  rno'lify  the  instincts  aln-afiy  |k»s»ssp(1  l»y  th»- 
MelipDiia.  and  in  tlieniselves  not  vcrv  wonderfiilj  tlii^ 
licc  wiuilrl  make  -j  -tnicture  as  w<pii(ifrfiilly  |>ertVct  as 
t)i,it  of  the  hiv>-hee.  \\'e  must  suppose  the  Mdipona 
to  make  her  cells  truly  sphorical,  and  of  equal  »i^rs  ; 
and  this  would  not  he  very  surprisiiitr.  sp«^niL'  that  -.he 
already  doe-j  so  to  a  certain  extent,  and  >oei!iir  what 
pertectiv  cylindrical  hurrows  in  wood  ruanv  i[i*c.-Ls  can 
fn.ike,  apparently  \r,  •uminir  round  on  r  ''xed  point. 
\\  e  itiii.-t  supp(»se  the  Melipona  to  arranre  her  cells  in 
level  layers,  as  she  already  does  her  cylipdrical  ''idb  : 
and  we  must  further  supjiose,  and  this  is  the  t:reatest 
ditluulty,  tliat  slie  c^ti  somehow  iudtre  ai'curately  at 
what  distance  t(»  strand  from  her  tellow-lahourer-  wlieri 
several  are  makinjr  tlieir  srdieres  ;  hut  she  is  alreaily 
-o  far  eiiaided  t(,  judtre  of  distatice.  that  she  always 
descrihes  fier  spheres  so  as  to  intersect  largely  ,  and 
rhen  she  unites  t.hp  points  of  intersection  hy  perfectly 
?iat  surfa.  cs.  \\'<.  liave  further  to  supjwwo/hut.  this  is 
no  dithcjlty,  that  after  hexatronal  prisms  have  Iteen 
formed  l.y  the  intersection  of  adjoinirnf  sjdicres  in  the 
same  laye-,  sho  can  proloajr  the  hexaL'on  to  any  len^rth 
re'jui>ite  to  h(dd  the  stock  of  honey  ;  in  the  sanu-  way 
.T<  the  rude  humhle-hee  adda  cylinders  of  wax  to  the 
circular  mouths  of  her  old  cocoons.  !lv  such  I'louitica- 
t.ions  .(f  in-tincL-  in  themselves  not  very  rtunderful,-- 
liardh  more  wonderful  than  those  winch  truide  a 
t>ird  to  make  its  n^'st,  —  I  htdieve  that  the  hive-hee 
tia^.  acijiiired,  throuirh  natura.  seleition,  her  iriimitahle 
arc}i't('<'tural  powers 

Itiit  this  theory  --an  he  tested  hv  experiment, 
(■■.dl.'wiiijr  the  example  of  Mr.  leiretrneier,  1  separated 
two  coiiil.-.  and  put  hetween  thetn  a  loiiir,  thick,  siiuare 
trip  of  wav  :  the  l>ees  iiistiintlv  he^'^an  to  excavate 
niinhte  circular  pi*s  in  it  ;  and  as  they  de«'pened  the-^e 
little  pit'^,  they  uiade  them  wider  aiid  wider  initil  thev 


INSTINCT 


20S 


were  couvert»'d  into  shallow  basins,  app«*ariiitr  to  the 
eve  perfectly  true  or  jmrts  of  a  spher*',  and  of  about 
the  diameter  of  a  cell.  It  was  most  interestiiijr  to  me 
td  t>twerve  that  wherever  several  hees  had  detr'ni  to 
<'\<\i>ate  tliese  ha>ins  near  toiretht-r,  they  hau  be^run 
tiieir  work  at  such  a  distance  from  eacli  other,  that  by 
the  time  the  basiiH  had  acmiired  the  above  stated 
*idth  (!.»'.  about  the  width  of  au  ordinary  cell),  and 
Aere  in  depth  abnut  one  sixth  of  tbe  dianiefer  of  the 
-phtTc  of  which  they  forme<l  a  part,  the  rini>  of  the 
ba>uis  intersected  or  hrol<e  into  each  other.  As  soon 
i.-^  this  occurred,  the  bees  ''eased  to  excavate,  and 
lieu'".an  to  build  up  Hat  wu!'  of  wax  ori  the  line-;  of 
'Mfer-ection  between  the  l)ii.«uis,  so  that  f;iih  iie\,n.'i>nal 
;iri><in  w.v>  built  ii[ion  the  scalloped  eiij^e  of  a  sinnoth 
iia<in.  instead  of  on  tlie  str<ii::lit  edire^  o;  ;i  three--ided 
pvrainid  as  in  the  ca-^e  of  ordinary  celi-. 

1  then  jtut  into  the  liive,  instead  of  a  tliick,  scpiare 
piece  of  wax,  a  thin  and  narrow,  kinte-e<i_re(i  ridire, 
coloured  with  vermilion.  'Jhe  bees  instiintly  beiran  on 
both  -i.les  to  e.xcavate  !  'tie  basins  near  ;o  eacli  other, 
in  the  sjime  way  as  before  ;  but  the  ridtre  of  wax  was  so 
thin,  tliat  the  buttons  of  the  l»asins.  if  they  had  been 
excavate<l  to  the  same  depth  a.s  in  the  former  experi- 
ment, would  have  broken  into  ea<"h  other  from  the 
oj'po-ite  sides.  The  bees,  howe\er,  did  not  suffer  this 
to  liappen,  and  they  stopped  their  exca'.ations  in  due 
time;  ■-•o  that  the  liasin-^,  a.«i  soon  as  they  h;id  U«en  a 
little  deej)ened,  came  to  have  ilat  bottoms  ;  and  tliese 
llat  bottoms,  formed  by  thin  little  plates  of  the 
vermilion  wax  having  been  left  untrnawed,  were 
situ.ited,as  far  a.s  tlie  eye  could  Jud^'c,  exai-tly  aloriir 
the  planes  of  imaginary  intersection  between  the  basins 
on  tiie  opposite  sides  of  the  ridije  of  wax.  In  parts, 
oiily  little  bits,  in  other  parts,  larire  portions  of  a 
rhombic  pl.-ite  had  been  left  t»etween  the  oppo-ed  !ia-ins, 

l..,»  ll...  ,.  .»!'  i'>,.n,  *\^n  •<  t<,.»»..  rnl  .£•'>»<>  ■•*'  »l,;>i.r^'  l.irl 
■•■:-.     ..  J :  T.-     "  ..  -;  r-.  ,     :  !  **  ::i      •  ii*       .  t  t  ■  •  I't '.  -.a  Ftt  t      ^..,.»      ...      .,...._-       ...... 

Hot  been  neatly  performed.  'I'he  bees  ri\u«.t  have 
worked  at  very  nearly  the  same  rate  on  the  opposite 
side.-'  of  the  ridfje  of  vermiliou  wax,  a.s  tiiey  circularly 


2f»« 


ON   THE    ORIGIN    OF   Sl'ECIES 


iriiawed  awa\  and  decpene'l  llie  basins  on  lK)th  sidesj  iu 
order  \i<  lin.o  suci'oedcd  in  tlius  leaviiji:  fiat  plate* 
hctwpfii  flie  lasiii-,  iiy  slojipinp  work  a'oiitr  tlio  intt'r- 
tnt'diat*'  [ilaiies  or  pWuics  ot  iiitcrsoiti'in. 

(  on-idcrinK  ln'"  i!«>xi!i!»?  tliiii  wax  is,  i  d(»  not  -see 
tliat  there  is  any  diflirLlty  in  lli(^  Itcs.  v^liilst  at  w<irk 
im  tlie  tuo  sides  ot  a  t^trip  of  wax,  penciviiitr  wlicii 
tlicv  lia\'^  trii  I'.u'd  tlie  wax  away  to  the  jimjicr  tliinncss, 
•111(1  tlicn  s^ojijiuic  llH'ir  work.  In  <i:diriary  combs  it 
ha-  appi-arod  to  me  t'l.at  tli»'  bees  do  not  al'-«ay8  Piu'i«'od 
m  workiiiiT  at  exactly  the  s.im"  rate  trnni  the  opjios-»(> 
hides  ;  for  I  have  noticed  ha't-comph'tt'd  rhombs  at  the 
Itati-  (if  a  iu-t-comnieiiced  cell,  which  were  slii,'htly 
<  (incavc  on  one  sidf»,  \viiere  I  suppose  tiiat  the  ln'c^  had 
evcavate(l  too  juickly,  and  coinex  on  the  opjiosed  side, 
where  the  bees  had  "urktwl  less  (pnckiy.  In  one  w»-ll- 
Tnirlcd  iii'«t-'i!ice,  I  jnit  the  comb  hack  into  the  hi\e, 
and  alhiHi-d  the  bee-  t.  e<*  "'i  workitiL'  for  a  sliort 
time,  atui  UL'ain  examined  the  cell,  and  1  found  that 
the  rhi>nih:c  plate  bad  lieen  roni!'!eted,  and  bad  hci onic 
pfrirftiij  fict :  it  wius  alisoIutei\  iiujios^-ible,  fr<i!ii  ihi' 
extreme  tliinness  ot  the  little  rhombic  i>late,  that  they 
« Olid  liave  elfected  this  by  tr'i:i"'Mi;r  away  the  convex 
side  ;  and  I  su-pcct  that  the  bet"''  in  '•uch  cases  staixi 
in  th»(  opposed  cells  and  push  and  bend  tlie  ductile 
ftiid  wai  ii:  wax  (whicli  as  1  have  tried  is  easily  done) 
intit  its  proper  interniediate  plane,  and  thus  datten  it. 

I'rom  th(3  ei)>eriinent  of  tlie  ridi^c  of  \'ermilioii  wax, 
we  c.in  (  learly  >ee  that  if  the  bees  \*ere  to  liuild  for 
thenis(d\f-  a  thin  "all  of  wax,  tlu".  co'ild  make  their 
ceils  tif  tlie  jiroper  sha|'e,  by  staudiiii;  at  the  |irop«'P 
<listance  from  enli  other,  by  ext  avatiiiu''  at  the  .s^inie 
rat.',  and  by  endeavourinij  to  make  et|ii,il  spherical 
hid'owv,  but  ne\cr  allov.ini'-  the  spheres  to   'oreak   into 


each  o'her.  Now  bees,  as  may  be  eh--irly  seen  by 
«-xaininiii:r  the  ed^'^e  of  a  growintr  comb,  do  make  a 
ruiiLrh,  circumferential  wall  or  rim  all  round  the  ( omb  ; 
■iiid  they  ^iiaw  into  this  from  the  0]>p('-ite  sides,  always 
workimr  circularly  a.s  they  deepen  each  cell.  1  hey  do 
not  make  the  whole  three-sided  pyramidal  l>ase  of  any 


INSTINCT 


207 


oiiPCf'li  at  tho  s.-ipif  timt'.  hut  only  tliPone  rhomhic  plate 
which  stands  on  the  extrrmo  ^rctwin?  marifin,  or  the 
two  jil.'ites,  a-  t)it«  case  inay  i'o  ;  aiu!  thev  n»'\er  loin- 
jilfte  t'lM'  iipjier  e(li:'*<  ot"  the  rlioiii'iif  |,Iato<.  'intil  th»' 
Iie.\a:.'(inal  walls  arc  tntntnem-pd.  Norno  <»t  tln'x-  >tatr 
iiirnts  (iiifcr  from  truo-  inaiU'  by  tlio  iu>tlv  celcliratrd 
cMfr  Muher,  tint  [  am  lOininred  of  their  accurary  ; 
ai.ii  if  I  liad  >[ihcp,  I  couM  -Ikiw  that  thov  an*  rniifurm- 
alilt'  willi  my  tht-ory. 

Hiih«n's  statcnit'nt  that  the  mtv  f;r<t  (•«'ll  i^a 
I'vcavatt'd  f)iit  of  a  litll»»  jiarailol-'^iiiffl  \vall  of  wax,  \a 
ji'it,  as  tar  as  I  have  soeu.  strict] v  i-nrrert  :  the  first 
t  .'inirK-ncenuMit   liaviriir   alwav-    hecii    a    littlo   Jiooil    of 


wax  ;    hut    1  wili  not  liere  i'-.-.U'v  on  these  de'ail 


We 


scf  liow  irniuM*'"*  a  part  excavation  plays  in  the  cori- 
-tnictidii  of  til'  s;   hut  it  wn:ild  ho  a  (.Tcit  »Tror  to 

>!ipp<',(.  tliat  t'l  H  es  caiuiot  h'nld  up  a  rouL'h  wall  of 
v*a\  ii!  the  proper  position-  (hat  is,  aloii_'-  tli''  piano  of 
intersection  between  two  adjoininjf  Hpht-res.  I  liave 
-'"MTal  '^pet-imens  sliowinir  clearly  tli  it  tiiey  can  do 
tfiis.  K\en  in  the  rude  circumferential  rim  or  wall  of 
«ax  round  a  trrowin-r  iMmh,  tlexnres  may  sometimes  be 
(■'i-crved,  <orre^pondini.r  in  |)ov!tiii!i  to  the  phines  of  tlie 
riiomhic  iia-al  plates  of  futnn-  rell<.  Hut  the  rourh 
wall  of  wax  h  is  in  evory  ea«e  to  he  finished  oif,  hy 
liiin::  lar^'ely  ^'iiawed  aw.iy  fn  Imth  >!iies.  The  ni.iuneV 
ill  ^\iiich  tlie  bee-  build  ;•*  curious;  thev  alwavs  make 
ti:i'  first  rou^rh  wall  from  ten  to  twc-itv  tinn's  thicl.er 
tiian  tlie  exce»ivelv  thin  lini-lied  wall  of  the  cell, 
xvhich  will  nltim;itely  hi'  left.  \\  e  -Ii  ill  understand 
hnw  they  work,  h}  suppo-iiiir  masons  tn--t  to  pile  up  a 
hroail  riiiire  of  cement,  and  then  to  he:; in  cuttinir  it 
away  eijially  on  both  side-  noar  tin-  jro'ind.  till  a 
-loootli.  \cry  thin  wall  i~  \vl\  in  tl,,-  rniddle  ;  ihe 
Til  i-on-  always  pilinjr  up  the  cut-away  cement,  and 
aiiiliiiL''  fre-li  cement,  on  the  summit  of  the  riflire.  W'e 
-hall  thus  liave  ;i  thin  wall  steadilv  trrowinir  upward  : 
l>ut  always  «  -owned  by  a  ^'ij^antic  copin;r.  From  ail 
tlie  cells,  both  those  just  commenced  and  tho-^e  com- 
j>leted,  beinjr  thus  crowne«i  by  a  stroujf  copinj^  of  wax, 


Ii 


208 


ON  THE   OUIfilN   OF  SPECIES 


the  Jices  ••an  cluster  and  crawl  over  tlie  comb  without 
injuriritf  the  delicate  liexairoiia!  -.alis,  which  are  only 
about  oih;  rdiir-luindredth  of  an  Mich  in  thickness;  the 
(dales  of'  the  j)\  ramirlal  h.isis  \,c\ui:  ahoiit  twiie  as 
'.hick.  Ily  thi-  sinirular  manner  of  huildinjr,  strerifrth 
is  cditinually  u'ixen  to  the  conih,  with  the  utmost 
ultiTiiat«>  e«-oiiuiiiv  of  wax. 

it  -eenis  at  rir^t  to  a>\ii  to  the  dJIIiniltv  of  undcr- 
staiidiiiir  liow  tiie  vrUy.  are  made,  that  a  multitude  ot 
bee-  all  «ork  r(i::.'thcr  ;  one  hee  after  uorkinyr  a  <h(irt 
time  at  one  c(di  ircdnir  to  anotlicr,  mi  that,  as  fluher 
has  <tareil,  a  seore  of  individuals  work  even  at  the 
.  omineiicerio'iit  of  tlie  fir>t  cell.  I  was  ahle  jiracticallv 
to  >\ut\\  this  fact,  hy  coverin::  tlie  »'di:.->  of  rh'e 
hexajronal  walN  of  a  Kin<:le  lell,  or  the  extrcnu"  marL-in 
of  the  circumferential  rim  of  a  urovMnt:  <-(iinh,  witli  an 
evtiemtdy  tiiiii  layer  of  melted  vermiiion  wax  ;  and  I 
iinariahly  found  tlial  tlio  colour  was  mo>t  (Iclicately 
diffll^ed  l.y  ttie  hees  -as  deli.-ately  as  a  painter  could 
lia^e  d(»ne  with  his  hru>h  hy  atoms  of  the  coluured 
wax  havini:  hiM-ii  taken  from  tlie  ^jiot  on  which  it  had 
been  ]ilace<i,  and  worked  into  the  trrowinif  edtrt's  of  the 
cells  all  round,  'i'he  v<  ork  of  construction  seetiis  to  bo 
a  sort  of  balance  struck  between  r7iany  l-ees,  all  in- 
stinctixely  standing  at  the  same  relative  distance  from 
•>ach  other,  all  trying'  to  swccj)  e<iual  spheres,  and  then 
buildiiitr  up.  or  leavin^r  wn^rnawed,  the  planes  of  inter- 
section between  these  spheres.  It  was  re;tlly  curious 
to  note  in  ia>es  of  dithculty.  as  when  two  piece^  of 
comb  met  al  an  aiiL'lc.  how  often  the  bees  would  pull 
down  and  reliuild  in  ditferent  ways  the  same  cell, 
sometimes  recurrin^^  to  a  shape  which  they  had  at  first 
rejected. 

\V\wu  bees  have  a  place  on  which  they  can  stand  in 
tlioir  proper  positions  for  workintr.  for  in-tance.  on  a 
slip  of  wood,  placed  directly  under  the  middle  of  a 
comb  t'rowinir  tiowriwards  so  tliat  the  comb  has  to  K-e 
tiuilt  over  one  face  of  the  slip  in  this  case  the  l)ees 
can  lay  the  foundations  of  one  wall  of  a  new  hex.i^vni, 
iu  its  strictly  proper  place,  jirojectin^  bey(»nd  the  other 


INSTINCT 


209 


completpd  coll-^.       Jt  sufHics  tint    tho  hees  should   Im» 
eii.iLioii  ti)  stanil  ;it  their  piopfr  rrlativf  distAiici's  from 
t'Hi  h   oth«T  ami    twin   th(»   u;ills  <>t'  tii.'  l.i^t  romph-ted 
cfllv.,  ar:d   tlieu,    \n    .-trikititr    ima^'iiiiirv   sphtTtw.   they 
t.i'i  hiiil.i  up  a  wail   iiiteriiji-diatr   ht'twet'ii    tuo  adjoin- 
ing'   spheres  ;    l)iil.   a.s   far   as   J    have  seen,    tliey  never 
KiiaH  away  and  tini>h  oti  the  antrie-  of  a  cell  t.lla  laru'e 
J. art   hotli  oJ   that  cell  and  of  thi-  adnuniiii:  reil.s   hn- 
•  >••♦  ;i  hiiilt.      'I"iii<  capaeity  in  Kee-  of  hiyiniT  down  under 
.'.Ttaiii  circum.staiices  a  routrh  viall  iii  it-,  proper  plan- 
t.'tvM'eii  two  just-roiiunenced  ceils,  is  important,  as  it 
hears  on  a  fact,  whii  h  seems  at  first  (piite  Miti\er-i\e  of 
the   lorciroiiiir   tlieory  ;    namely,   that  tlie   eells  on   the 
e-vtretne  mar-in  of  wasi>-c-oinh>  are  sometimes  --trirtlv 
hex.-iiTunal  ;   hnt  I  ha\e  not  s[).-iee  here  to  enter  on   tlii's 
kuhieet.     Nor  does  there  M-em   to  me  any  treat  ditfi- 
•lilty  in  a  sin^h-  inw,.,t  (as  in  the  case  of  a'ljueen-wasp) 
ni.ikin^  liexatronai  cells,  if  >he  work  alternately  on   the 
iiisi<le  and  outside  of  two  or  three  cells  commenced  at 
the  name  time,  always  st-mdiiiir  at   the  jjroppr  relative 
distance  from  the  parts  of  the  cells  just   heiruu,  sweeji- 
!!i-'-  spheres  or  cylinders,  and  huildinir  up  intermediate 
[•iiiifs.      It   IS   even   conceivaMe  thai  an   insect   mi^rht, 
M   rixinjT  on  a  poim  at   whuli  to  «-ommence  a  cell,  and 
ti..  11    movin*?  outside,  hrst   to  one  point,  and   then  to 
n>e  otlier  pointj^,  at  tiie  j. roper  nlalne  distances  fr-.m 
tiic    cuutral    p.,int   and    from    each    other,    strike    the 
J.1..IMM    of    intersection,     and     <o     make     an     isolated 
.'ie.\;itfon  :    hut   I   am   not  aware  that  anv  siicli  ca^e  has 
i>een  ot.served  ;   nor  would  any  t:o.i.l  f»-\h.ri\ed  from  a 
■iiiit-ie  liexaifon  heiut.'  huilt,  as  ni  its  construction  more 
ninteriais  would  he  retjuired  than  for  a  cylinder. 

As  natural  selection  acts  onlv  hv  the  ac-umulatiou 
ot  >^li;-'-ht  modifications  of  structure  or  in«.iiuct,  each 
jToiitahle  to  the  imlividual  utider  it.s  conditions  .'.f  life, 
t  may  reasonahly  he  asked,  iiow  a  louu^  and  trnidualed 
-uce.-Mon  of  moditi.'d  architectural  instinct-,  all 
•eiiuintf  towards  the  present  jx-rfect  plan  of  coiis'truc- 
iion,  could  have  profited  the  proirenitorH  of  the  hive- 
'"•  '     1  think  the  answer  is  not  diflicult :    it  is  knowu 


M 


^ 


210 


ON   THK    OIlKilN    OF   hl'K(  IKS 


1 


that    UtM'>    arc    nfU'ii    li.inl     jin>s-tMl    to    m-t    surfirient 
nectar;  aii'l  I  ;ii..  jiifnrtiicil   liy  Mr.    I  circt  iiit'it'r   that  it 
lia'^  Im'cii  »'\iM'rimt'!i';illv  tniirnl  tint  ii"   L'--^  tli;iii   trum 
Iwclvf  til  lillfcii  |i(iiiki!n  o}   (li  y  siu.ir  arc  <  nn^uinf^l  'ly 
a  lii\<'  111    Imt-^  fi.r  liif  scrrcin-i  i.i   iMth  |i<iiiiiil  nt   wax  : 
til  tluit   a    |iriiili.'i()ii-;  (|ua!iiitvoi    tiiiid   m<'tar  mu-^t   W 
ntlii'itrd   ami  ntM-iniicd    l.y  ilio   I'ft's  in   a  hivo  tor  lli(- 
-fcicti.'ii  (•{  tin'  nav    iii'c('><ary  Tor  tlie  coiistriK  lion  of 
tln'ir  riiiiil'-.      Mii;i'M\,'r,  many  Im'Cs  liave  tn  rfm?iin  idli' 
tnr   iiKinv    ii.iv>    fiiiiiiiu'    'li'"    ,'r<trcs8  of  sn-rt Hon.       A 
larL'*'  store  <it   lionrv  is  !i;<ii>it'n-a'il(>  to  -iipjiort  a  lartT? 
-tock  ol'  ln'f-  (lunri'.''  tin-  \vi(il»T  :    ami    tlie  ^oruritv  ot 
Ihi"  !ii\t>  i<  l\']ov.  II  iiiaiiilv  to  dt'iM'f!.!  on  a  laru'e  luinihor 
lit  hccs  1,1'iii^  >ii|.j)oit(d.       Hciri'   'i;i'  -avmu'  "?"  wav  liy 
lar_'.'l\  •..!'.  in;i  lionr\  rimst  In-  a  nn-t  iinj'orlan;  »'li'in<>nt 
of' ^:n  ri'-.-  in  any  tanul\- ot  lit'cs.      (  '1  courso  tin'  sun-fs-i 
ut  any  >j>»rii's  ot  Wtf  may  hi'  dcjiondi"'  on  thi'  nunilx-r 
ot  its  jiara^iU's  or  other  rm'niU's,  or   oti   quite  di>tnu't 
rauM's,     ami     <o     I'O     altoL't-tlier     imhmi'mlcnt     ot"    the 
ijiiantil}'  of  lio'ii'V  w  lii'h   the   lu'es  could   coilect.      IJut 
let  us  sujipO'^e  that  tins  latter  circum-tanco  detenu incd. 
a^  it  jiroliahlv  ottcn  docs  dctcrrnnic,  tlie   numhers  ot  a 
liunihic-l'ce  which   could   exist   in  a  country  ;    and    let 
u^  I'urtiier  s'i|»[,o-e  tliat  the  coinnninity  li\(>ii   thri>u;rh- 
out   tlic   uiincr.  and  citn«e'|uently  reijuired  a  store  of 
hot;cv  :   there  can  in  this  ea-e  he  no  dmiitt  that  it  would 
he  an  adxantaire  tn  our  hunihlc-hee,  if  a  sli^'ht  n'oditica- 
tion  of  ]ii  r   ni^tinct   led   )u'r  to  make  her  \vai<'n   celU 
near  to^jetlier,  <o  as  to  intersect   a   li!ile;    foravsall   in 
coiiunon  even  to  two  adioininir  ceI!^,  would   sa\e  some 
little  wax.      liciu'c  it  wiuild   confiiniaily    he  more  and 
more  ail \ant.ijcous   to  our  humhle-1'ee,  if  she  were  to 
make  her  cell-  mo'-e;ind  n,  ire  regular,  ne.uer  totretliiT, 
and    a_-re-ated    into    a    tu.i-s,    like    the    cells    of   iho 
Meli]ioii.i  ;   h»r  in  this  ca-e  a  lar^-^e  pnrt  of  the  houndinjf 
surface  of  each  cell  would  -erve  to  iniund   other  cei'-, 
and  much  wax  \Miuld  he  s;i\  ed.      AiTam.  from  the  samo 
cau>;e.    it    would    ito  ad\antai:cous   to  the    Meiipoiia,    if 
slie  were  to  make  her  cells  closer  toLM'ther,  and   more 
reirular  in  e\ery  way  than  at  j>re-cnt  ;    for  then,  as  we 


INSTIN(T 


211 


}iavp  RtHn,  tho  splionral  siirfares  would  wholly  Hi»- 
;i|.j"'ar,  «iirl  would  ,ill  l>o  rpj)la««*d  hy  |dniip  •'urt'accs  ; 
r'l.d  tlip  MtdijMiiia  would  niak*^  .t  conili  ;ts  (uTtVrt  ns  tliat 
;,♦  tl.t"  liivc-!n'o.  i;»')iiiid  th;>  -t;i_'»'  '>(  jif>r!V(ti(>!i  in 
ar<"hit<'<  turt',  iiriMirril  srU'itidii  cinild  nut  U'.ni  ;  fur  the 
o'lili  of  tin*  liiv»>-l)('c,  fiH  f'nr  as  we  i  rtii  -ce,  is  aKsoluNdy 

(K-rfc-t   ill    OCdllnDii-lIiir   \v;iN. 

'Ilius,  as  i  h^lic. c,  till'  must  woiidorful  ut  all  known 
•-t'licts,  tliat  of  tlio  lii\  c-Imh'.  can  lio  •  rp'.ainrd  hy 
I  atiiral  sclt'ctinii  lia\inL''  tnkpu  ad\;i!it,'ii:(»  u*  nuniprou^, 
«ucct<si\j.,  fihi^lit  moflitira'ion>  of  -irnpU'r  inntiiirts  ; 
natural  sclprtioii  liav;ii:r  hy  >io«  dj-iTccs,  niore  and 
irioro  ji'Tifftly,  led  t)'p  l.t'c-  to  sweep  tMiual  spluTos 
il  a  rivon  distance  from  cacli  ollipr  in  a  douMe 
!i\f'r,  ami  to  Imild  u]f  and  t•\ca^at»'  the  wait  along 
th''  jiiancs  of  int(Tsr<-ti(.n.  I'ln'  I'ocs,  nt  coiir-p,  no 
ri'iirp  kriowiii.T  tliat  tlioy  swpjil  tl;»'ir  splicrcs  at  one 
i-a'-ticular  di-tam-c  from  oacli  otlter,  tlian  tlu'v  kriuw 
uliat  are  tlie  several  aiitrlcs  of  tlic  lioxajrona!  [iri-nis 
and  of  tlio  Ka>ial  r)ionilii(!  idatp-*.  i'lic  moti\<'  puwcr  of 
the  process  of  natural  solcctiuii  liavinir  hcen  economy 
u*  wax;  that  iii'liviilual  nwjirrT'  ulii'-li  sa-tcd  least 
honey  in  the  secreiiun  of  wax.  havinir  suci-eeded  he>t, 
H!i'i  liaxinii  tr.insiiiitted  hy  i'llK-ritiiiice  its  newly  ac- 
(jiii'-cd  econoniiral  iiisliiirt  to  new  swarm-;,  wliich  in 
til*'  r  turn  will  ha\e  had  the  host  cliance  ot  >ucce«<ling 
■n  the  struirt:!*'  for  exinteiu'e. 


No  douht  niaiiv  irjstiiicts  ot  vc-ry  difficult  explanation 
c<'i:'d  lie  (>p]>(ise<i  to  the  thcorv  ol  iiatur:''  ^election. — 
ca-c«,  i:i  w'h  ch  we  caiiiiot  sec  liow  an  iMBtiiict  could 
po-^hlv  hive  oriirir.ated  ;  cases,  in  which  no  interm"- 
diate  trradatiotis  are  known  to  exist  ;  cases  of  instinct 
ut  a]i]nre!itl\'  such  trin  ri;;  imj)ortanc<'.  that  they  conid 
h.trdlv  have  hetii  acted  on  hy  natural  seleclum  ;  case<< 
of   instiiict.y  almost  identicallv  the  same  in  animals  lo 

for  their  similarity  hy  inlieritance  trum  a  co  Timon 
parent,  and  must  therefore  helieve  tiiat  tlie\  have 
tn-eij  ac(juired  hy  independent  acts  of  natural  sel-ctiou. 


212 


ON   TfiK    ORIGIN    OF   SPKCIKS 


I  will  not  here  enter  on  tJu'se  >.»-\er.'\l  <.i«t-,  hiil  will 
confine  myself  to  on»»  s|X'ii,il  liiffirulty,  whi«  li  .-it  fust 
aj>j>car»'<i  to  mo  in'ii|n'r;ililf\  ami  .ittually  fatal  fn  my 
wiioic  tlii'ory.  I  alluilo  !o  the  lu'iitcrs  or  -^torilr  females 
in  in'«ei't  t;ommuinti«'>  :  for  (li»'««e  neuters  often  liitfer 
wiilely  in  inhtimt  nnd  in  htrurtnre  from  Ixitli  the  niaics 
ant]  t'crtile  females,  an<i  yet,  from  livini:  >«teriie,  ihey 
ciinnul  propatrate  their  kind. 

i  he  Hiilitoct  well  ilps««rves  to  he  di>>ru»-e(i  at  irreal 
leiii/lh,  but  1  will  liere  Uike  only  a  Mni:ii'  oavp.  that 
of  worknit:  or  slenio  aiiLs.  How  the  v*t>rkern  ha\e 
V)oen  reiiiiercMJ  sterilt?  in  a  difHculty  ;  imt  not  much 
ifreater  tlian  that  of  any  other  striking  monifiration  of 
HtriKtiire  ;  for  it  tan  !>»■  ^liown  that  some  in-»*<t^  and 
other  articulate  animals  in  a  -state  of  n.'iture  <»<'asion- 
ally  hfiorne  sterile  ;  and  if  such  insects  had  heen 
social,  and  it  liad  l>efn  profiUihle  to  tlie  coiiirnunitf 
that  a  niiiiilter  should  ha\t'  l»eon  annually  Imrn  cajialde 
of  work,  hut  incapahh^  of  procreation,  I  can  see  no 
ver\  jrreat  dilliciiltv  in  this  heintr  effected  hy  natural 
■.ele«-tiiin.  llut  I  must  jm^s  over  thi*  preliminary  diffi- 
<ult\.  The  trreat  difficulty  lieh  in  the  working  ants 
differini.''  widei\  fr'>in  iioth  the  males  and  the  fertile 
females  ifi  structure,  as  in  the  -iiape  or  the  thorax  and 
in  Irfiiur  destitute  of  winj^v  ami  sometimes  of  eyes,  and 
ir»  iiislim'.  As  far  a,s  in>-tinct  almie  is  concerned, 
tlie  prodnrious  dirfercnce  in  Ihi-  resjiect  hetween  the 
workers  and  the  jtertVct  ft-rnale-,  would  havf  hcen  far 
hetter  exemiditicd  l>y  the  hue-l>e«'.  1  f  a  Morkii!:f  ant 
or  otiier  neuter  insei't  had  been  an  animal  m  llie 
<ir<linary  state.  I  sliouiii  ha\e  unhesitatiutr'y  as'-^uined 
that  ail  its  characters  had  been  slovriv  acquired  (hroutrh 
natural  selection  ;  namely,  hy  an  individual  haviujf 
been  born  with  some  slight  profitable  modiiicatiou  of 
•  tnicture,  tlii-  bciii::  inlier;te<i  by  its  otf-pnng,  which 
a^ain  \aried  and  were  at'^ain  selected,  and  so  oimardn. 
liul  wiih  tht!  workintc  ;int  w**  have  an  in>-ect  differins; 
jfreativ  from  il.s  parents,  yet  altsolutely  sterile;  so  that 
it  couid  never  hase  transmitted  successively  acquired 
mtxiifications  of  structure  or  instinct   to   its   progeny. 


INSTIN(T 


213 


jt  may  "fll  ^e  a.ikwl  liow  i^  it  jimsmMo  to  reroticile 
tl  in  rase  witli  tlie  t)i«>ury  nf  iintnral  '<i»le«-tiori  ' 

Kirxt,  let  it  1>«  r«'riieinl>or(»d  t)i.it  wo  liave  iririumer.iltle 
ins'.iiicorf,  hufli  in  our  .lntnostir  jir<H|iicfi.<n-<  aixl  iti 
tlioso  in  a  nt.if»«  of  nature,  of  all  H<»rtx  of  riirf«»r»Mire« 
of"  Htrurture  wlii.ti  hii\a  hoconio  (Mirrol.ited  to  certain 
.iL"'?»,  ^iiil  to  either  «'x.  Wo  li,i\e  ditfrrfnt-e**  corre- 
iiifed  not  c»niy  to  one  sex,  loit  to  that  short  imtIikI 
al'Mse  wlien  the  rejiriniuitiNe  svsti^m  is  iutivo.  us  iti  th«' 
iPMitiai  pliiin:itrt»  of  manv  lirds,  arnl  in  tlio  ho<ike<l 
ta".*s  of  the  mile  salmon.  We  have  even  slu^ht  Hitfer- 
ei'.cos  ill  tlin  horns  of  different  l>reed«»  of  cattle  in 
roiatif)!!  to  Hii  .-irtificiallv  imperfect  state  of  tJie  tiifiln 
•^•\  ,  tiir  oxen  of  certain  Kreeils  lia\e  loiirer  !ior:m  than 
Hi  other  breed-,  in  conijiarison  with  the  lurns  nf  tjio 
hulls  or  co\v«  of  the>«  H.iriie  hreed-i.  Heiito  I  can 
•^ee  no  real  diDiciilty  in  any  character  liavinjr  liecnme 
correlated  witli  the  sterile  comlition  of  ce- uiin  tiiem- 
hen<  of  I'lsect- communiticH  :  the  oifficuitv  li"s  in 
iHiderstandinir  liow  «uch  rorrelatoil  rnodi'icatiniiH  of 
structure  could  have  >>een  slowly  acrumulafcd  hy 
natural  -election. 

This  difficulty,  though  apjiearin^f  insuperahle,  in 
lessened,  or,  as  I  believe,  (li>apj>«varM.  wlien  it  is  r»^ 
!nembered  that  selfM'tion  may  be  appl'"d  to  the  family, 
as  well  art  to  the  individiial.  and  may  thus  irain  the 
desired  end.  nius,  a  well  -  liavoured  vei:etaMe  is 
cooked,  and  the  individual  is  destroyed;  but  the 
horticulturist  oows  needs  of  the  same  stock,  and 
co'itidontlv  expects  to  eret  nearly  the  .same  variety: 
breeders  of  cattle  wish  the  I'.esh  and  fat  to  l)e  well 
marbU'd  to^retlier  ;  the  animal  lias  l>eon  slauL'hterefl, 
but  the  lireeder  foes  with  confidence  to  the  >ame 
familv.  I  have  such  faitfi  in  the  [lOwers  of  -elert^on, 
t>i.it  1  do  not  doubt  that  a  breed  of  cattle,  alwiys 
yieldiiitr  oxen  with  extraordinarily  lontr  horns,  could 
be  -ilowlv  formed  bv  carefulh'  watchitnr  which  indi- 
vidual liulls  and  rows,  when  matched,  prr>duct»<l  oxon 
•*:'';  the  loniri'-t  horn-  ;  and  yet  no  one  ox  couid  ever 
iia^e  propagated  its  kind.       Hius    1    believe  it  ba-*  been 


211 


ON    IHK    oKKWN    OF   SI'K(IK,S 


Willi  BOiiil  iii-rcL-H  .  .1  -ii^'l.t  (riOiIiIn-.-ition  of  stniclure, 
or  iiiHlinri,  riinelitol  with  th«?  >t<'ril«  niriditifm  of 
Cfrt.iih  ii.«.-ifil)t'rH  of"  tJi«  cnrniniiiiitv,  hi<i  hfcri  aiL.iii- 
tau«'"His  to  llii'  conunuiiily  ;  i  diim-ijih ntly  tfi««  M-rt  1»» 
ma!««-  ,V"I  iViiialos  of  tii«'  same  rtiiMriniuitj  ti<iiir:-li«»«l 
•ti<i  iiaii>roilt»-,|  to  tli»!ir  ferl;l«  oi^(»riiiL'  a  ti'ii(i««iii'v  t<. 
protiiice  >t<*ril«'  tinMiiliiTs  liavinj;  the  -Ninue  tiinduici.  .nn. 
AipI  I  t.rlif'.i'  th.iL  liii-  pr(ii'f«'4  li.n  '.fcu  r«'|.»-.itc.l , 
Uiilil  III. it  |>riil;t.'ioii>i  ;iiiiouul  <il  ililh-Kvi.  «  ln-lwreii  the 
fcrlilo  .iinl  iiTih'  t'eriiulo  of  the  -iiim'  -[lericM  han  heeii 
|»n>iiiii  I'll,  \*l,ii'h  w«  M'c  ill  rii.iny  "ncial  iiiscctx. 

Milt  we  h:'.. »'  imt  a^  yet  toijclipil  uii  lh<"  <  liniax  of  tlic 
(lillifii;\  ;  :.  Ill  .■|\.  tiu!  I'.n-l  iliat  thi?  nouters  of  se\er:il 
&iit'.  liniiT,  I  it  iiiiiv  trom  iIk-  k-rtilt*  f'fru.ilfi  .iinl 
rnalt'-,  Imt  iroin  carli  oilier,  sotiieUiiie-<  to  an  .ihm.st 
im:r»!(lilile  U»'4!;rfe,  .iii.l  ,ii»-  tluis  divuied  into  l.so  or 
even  flirei'  '■.i-lc-».  1  lio  ia»t(»-,  inrirfovi-r,  do  nut 
Ifeneraily  tfr.idiiate  into  »'aih  tittier,  l«;it  are  jierfVitly 
well  defined  ;  hei.ii:  ;i-*  distinct  ircun  e.ti-h  oflier.  .ts  are 
any  tvvo  spet.e-.  of  :lie  same  tieiui-,  (»r  ratlirr  as  any 
two  i:<-nera  oi  the  -^anio  family.  Thus  in  Keiton,  there 
are  wuikintr  ■irid  -oldier  neuters,  with  javvs  and  in>.linct« 
extraoruinaniv  ditferent  :  in  (  ry|i!ooeriis,  the  workers 
of  oi;e  taste  alone  earry  a  wonderful  sort  of  -hield  on 
th»:r  heads,  the  ii-,e  of  w  hirii  is  ijiiite  iinlvnown  :  m 
the  Mexican  Myrineeueystus,  the  workern  of  one  caste 
uever  leave  the  ii»'st  ;  they  are  fe<l  hy  tlie  workers  oi 
another  c.-isie,  and  tncy  have  an  enormoi:  Iv  de\tdoped 
alitluiiien  >vliich  accretes  a  sort  of  honew  siipjdv.njr  the 
place  of  that  e\»  reted  liv  tlie  aphidei.,  or  the  dcmiesli  ' 
cattli'  as  thi'v  mav  he  cHlled,  vftiich  our  Kuropeau  &ntM 
Ifuard  or  iinprisdu. 

li  v.ill  indeed  he  Ihousrht  that  i  have  an  overweernntf 
confiiience  in  the  principle  of  natural  selei-tion,  whfu  I 
do  not  admit  that  sucii  wonderful  and  well  estahli-hed 
(act^  at  once  annihilate  my  theory.  In  the  simpler 
case  of  neuter  in-ecLs  all  of  one  caste  or  of  the  .same 
kind,  whicii  ha\e  iaien  rendered  by  natural  selection, 
as  I  l)«'!ie\e  to  he  (juite  pos.sihle,  different  from  the 
fertile  males  and  females,—  in  this  case.  v*«  may  safely 


t   - 

f 


INSTINCT 


215 


.   >i.rlii(le  from  tlio  .iiialui:y  of  onliii.iry  v!iri.itit»ii>»,  thnt 
.•  .<li  nui:t«'->-n»',  ^licht,  pruht.iltit'   riKMlii'n  .itioti  iltii   not 
[.rdlijililv  III  tirst  apiiiMr  in  all  tin*  imin  itlnal  •  •  r.ti-rx  in 
;in«  saiUf  in'-t,   I'lit   III  a   It-w  alniic  ;    aiiu    tliat    tiy    the 
!i  iii;-ruiif;iiij''<l  M'leifioii  of   tlie  tcrl.lt*   [Mtcnt.-   »liicli 
Mro'lii-t'd  niixt  iifutiT"*  v.ilii  tlu!  |>m  t';;.i!.tf  iiioii.tii  a!:<'ti, 
il'    tilt'   hcutrri    liitiMiatfly    (Minf    to    lia^f    tin-   (le"*ire«l 
aractfr.      <  'ii  tin-,  virw  we  nii;:ht   o(  ra.-iniially  to  titid 
;.fiit»'r-ins»>ft.-  ot  tin'   -a'lif  Sjifiii's,   in   tin'  vaiiin  iir-t. 
I>i  ('-I'iitiiiir  crailatmn-.  nt  »triictiirt* :  ainl  tlii-*  «••  >lo  iin<l, 
.■••I  ollt-n,  roiisiiliTiiiLr   liu.v  low  in  iitfrii.-«'i  1  ^  nut   of 
i'.iirojie  hnvr   hcni  carffuiiy  »'3kaimiirti.      Mr.   I'.  >iiiitli 
h.i!*    Miov*n    Imw    surprisinL'ly    tin*    nrutfr-.    ot    -fxrral 
r.iiii>h  ant-i  itilftT  from  tarh  nthtr  m  -./.f  ami  »iiim'- 
tiuics    in    rolour  ;    and    di  .1    'he    »'xtriMti«'    form-    tan 
M'metirnes   li»'   |i«'rf»-i-lly  linked   toj^'cilirr  hy  imiis  idnaln 
t.i'  »Mi  out   of   thf  sam«   in>l  :    I  liavi-  riiy>t'lf  •■omj.tri'd 
;■.  rfoct  irradatioiis  of  this  kin<i.      It  ottt-n  happen-*  that 
till"   lander   or  tho  «-malli'r  -.i/a'd    workers  .are   tiie  most 
•inmerous;  «ir  that  holh  larsje  and  >mall  are  numerous, 
Mih  those  of  an  iiiternie<iia'e  si/.e  scanty  in  iiumhers. 
bormic-a   fla\a    iias    larjfer   and    •.mailer    worker-.,    vvith 
soiTie    of   inlt-riiiediate    f\/.f  ;    ami,    in   thi-i   «pecies,   as 
y,.      V.    >niii.i.   h;i.s  oi)sfr\e<l,    liio   lar;^er   workers  ha\e 
..)!nple  eyes  (ocelli),  which  tli<uii.'h  sm.iil  can  lie  pl.onlv 
1  -t;n^'!i>Iied,  wher«-as  the  -mailer  v\orker>   ha\e  their 
iicelli  rudinn-ntary.      ilavint;  carefully  di-.--ected  several 
-pecimeu-  of  the-e  workers,  I  can  aflirm   that    the  e\es 
a  e   far  more   ruiiimentary  in  the  smaller  wnrker-.  tiiaii 
I    II   he  accounted   tor   merely   I'V  tlieir    pn.poriionally 
le'-er   si/.e  ;    and    1    fully    (ielie\e.    though    1    dare    not 
a--ert  so   |Misitively,  that  the  workers  of  intermciliale 
-i/e  have  their  ocelli   in  an  exactly  intermediate  con- 
d  ' ion.      K  >    that   wf    here   hav^   two   hodie-  ot   sterile 
workers  in  the  ><ime  nest,  dilf'erin;:  not  only   in  si/e, 
hilt  in  their  organs  of  vision,  yet  comiei-ted   hy  somt 
tew    memhers   m   an    intermediate   condition.       I    may 
(l._'re.-s  l)y  addiiiir,  that  if  tiie  .-smaller  worker-  had  oeen 
the  most  useful  to  the  community,  and  thoM-  males  and 
fe'iiaies  hao  ite.-i  enrit  i'.;ialljr  selected,  which  produced 


210 


ON   TflK    OKKJIN   OF   Sl'EClKS 


i1 


more  mirl  rmiri'  ni  'lie  ^iiiillfr  ivorker^,  iintii  ail  the 
workers  lia.i  <()riH!  to  lie  in  tlii-^  cdiii  ;ion;  >v(' slioiild 
then  \i:i\i'  li;nl  a  -[mtm's  of  ant  witli  !:(Mif«>rs  \«tv  iioarlv 
ill  \\\f  -ainr  rni,(i:MMii  w.th  tlio-c  (tf  M '.rniii'a.  I  or  fln» 
worker--  ot  M}  iiiin'  t  haiC  lint  owu  ruil'Tr.ciU.'J  of  ocelli, 
tlion!.''ti  the  Tiiali'  and  teiiiali-  ants  or  tiu>  C't'ij-i  lia\e 
wt'll-rlevelniici]  0(  el  li. 

I  inav  iiiNc  one  other  ca-^e  .  >-o  coiitideiitl v  did  J 
evjM'et  to  fiiul  u--aiiati(Ui-.  ill  iiiijiortaiit  points  of  strtic- 
tu"  '!v\eeM  the  dirieieiit  ca^'e- of  m-'iters  in  thn  !*aine 
>»•'-.•  that  I  i:l.iiily  ii'w'iiled  nivselt  o:  \]v.  K.  >miih's 
•  • '•  -  of  TiMtiieroii-'  >tM>ei;ner.»;  froiti  f!ie  -arne  rie-f  of  the 
im;  i\"a.  '  AMuitinii  I  (It  V  est  Atriia.  I  lie  reador  will 
JM  I  li.-.p",  til  -I  ai'ji-eciHle  tiie  arnoi;!it  of  d'^ftTencp  in 
'  lic'C  woi'ker-i.  t,y  iiiv  iri\intr  ii>'t  the  aetual  iiiea^urp- 
!iieiit<,  hilt  a  st  rut  1\-  accurate  illustration:  t'le  .iit»,>r- 
fiee  was  t!ie  ^aiiie  .•»•»  if  we  w«'r(>  to  sec  u  m'  of  worKfiien 
loiildih;/  a  ho';-t«  (if  whom  nianv  >vrre  tivf  feel  tour 
imdies  luirh,  :<nd  nianx'  -iivtee;!  leet  hiL'^h  ;  hut  we  iinist 
supiiose  that  the  lar^'er  workmen  hid  h<-ads  tour  iii 
stead  111  three  line-  as  hi^j-  as  those  of  the  smaller  men, 
and  ia\*s  nearly  live  times  as  ii;!,'.  The  jaw-;,  mnrp 
<ner.  >i:  t lie  '.vork  iiiL'  ants  of  the  several  -i.es  fiitfere<i 
womlerMi ' !  V  m  >-h  ipe,  ai.i!  m  t(:e  furin  and  Tiuniher  of 
the  teetii.  IJut  the  important  tiict  tor  i;s  is,  tliat 
thouLdi  the  workers  ran  he  trrouped  into  rastes  of 
diih-reiit  si-es,  yet  ti'i\-  trradiiati-  insensihlv  ipto  each 
other,  ris  does  the  \Mdelv-<lirterent  structure  n*  'lieir 
JHWs.  !  speak  contideni'v  on  this  latter  jioint,  as 
Mr.  lj!''Ko(k  made  d'aviinirs  tor  ri.e  nith  the  camera 
luiida  oi'  the  iaus  ,\|.iih  I  had  dissected  troiu  the 
\\orker-  of  the  --eM'rai  -;/es. 

\\  ith  the-e  'aits  i cfore  nm,  j  he'lext*  that  natural 
selection,  i'l.  acting  oi;  the  fertile  par. "its.  could  form  a 
species  whiidi  should  reirulariy  produce  neiiters,  either 
all  of  l.irj'o  si/e  ■Aith  one  lorni  of'  -ia.  or  a!l  ot^  s;n all 
si/e  W'th  laAs  |;a. !!;;.:  i  w  i<!el\-  different  s||-ii<'ture;  or 
iasip,  ,  an*;  wirs  i^  (*"ir  x'i'iiiav  or  tiorn'uii\',  wiit*  sd  <»r 
worl  ers  of  one  si/e  and  »'ruoture,  and  sinniltaneouslv 
another  set  <d  workers  of  a  tiilfereiil  size  ami  structure; 


hf 


INSIIMT 


217 


a  ^r.iflua''><'  "prios  havintr  t>f»Mi  tir-t  tormt'ii.  a.-  in  tho 
case  of  t}ie  drivpr  atit,  and  tlieii  \)iv  extn"ii»»  forms, 
tmm  iM'iii^r  ♦i'*'  n>'>"^t  useful  to  tin'  roinnmiiity,  haviiij 
tjoe.'i  j.ro(l,ir»'<i  11  irrc-itcr  and  trreator  riiir!ii.t'r>  thrrMiirli 
tilt'  iiatiir-i!  -ii'ii't  iiiu!  of  the  j.Hrt'nt-;  wliuh  {.■■»-iif..itoii 
•'';cm  :   until  ijorie  with   an  intoniu'diate  stnictuiv  wcf 

'11. iH,   a-i    I    i'plif'vt^,    tli«>  vvorid.Ttul    f.'iot  o;    two  <i;'- 

tUH-tlv  (h'tint'ii   iastt'<  of  stt'rih'  wnrkcrs  existiiisr  in  t.-H' 

"aine 'ne-t.  Imtli  uiHciv  liiitprcnt    f'rotM   t'acli   I'lhcr  aiitl 

from   tlitMr   jiarcnt.-,  ha-*  ('riiriiiat*"!.      W  f   t;'.:i   't'O   •  "^^_ 

li-ffiil    lli^'ir    |»r(M!ii"-tioii    n.av    lia-.o    '<<ri-'.\    lo    a    -' c:.!. 

••«iirin,-ir,!!y   nf  i';vt>ct>,   on   •he  -an>t>   pr:  n'Mf>it'  tha'    t!"- 

.'ivi-ina  of  lal»":r  1-=  usetMl   ta  fiv.li-tMi   tiiau.      As  •i:.t> 

w.>'k  iiy  inhcnttMl  iiistinrts  an«l   !'y  mluTitcd  ori'-ans  or 

incU.   ami    iK't   !iv   aojuiroil    kiiowlcd;:*"  and    nianurac 

'.I, red   instruiiH'i.i-     :\    ;'i'rN>'-*   d'.vi-inn   of  la'.tiur  fouhi 

lu-    .'trecf.'d    with     tht-m    oulv    liv    tlii'     vorkors     lieiiit; 

-tfriie;    rrr    had   thev    ln'cn    fertile,  tliey   ■^<nl\<\    !ia\( 

.iiterrro>>i<-d,  ami   tlieir  iiis'Jiicts  and  ««trin'ture  womK' 

have  he.nine   tdended       And   uatnre  has.  .i-   I   I'elieve. 

etfet'ted  tln-i  admirable  division   of  lal^our   m   trie  (M.rn- 

ripin'tie-   of  ant-.,   hv   the  means   of  natur.il    ^election. 

Ku*   I  am    !M.und  to 'eoiifess,  Miat,  with  all    rnv  faith  n 

th;-    [«rHn-ii''e,    1    nhonld    never    ha\e   antirj'ated    thai 

natura'  -eleitioii  could    have   heen  etfinenl   \n  H"  h't-"}! 

a      eiiree,    had    not    the   ca<e   of   these   neuter    iiiseet^ 

oniir'.iued  ine  of  fie  faet.      I  h;i\e.  therefore.  di>.-u-;-e' 

tln-i  rase,  at  some  i.ttle  liut  wholly  in-utfiiient    .enifth 

I'l   oriitr  fo  ^how  the  power  of  natural  ^election,  ami 

likewise   heeause  this  is  hy  far  the  most  s»tumis  spei'in' 

d-i.icultv,    v\hi.li    mv    lhe<iry    has    enc<iuiitere(i.        I  he 

i'.'i»e,  also,   is   verv   interesting,   as  it   proves  that  wit't 

animal-i,   as   with   plants,   any   amount   or   ni.idifnatio'. 

in    structure    ran    he    eilf-'-teii    ItV   the  a.  euniuiation   of 

numeruMs,  -.I;_'ht,  and  a.-  we  mu^t  ea!l  them  aceidei.tal 

variations,  wliicli  are   ni  anv  manner  proii'.ahle,  uitti 

iM.i  e.\eni>e    or   ii.ioii    iiaViiitr   vOnie  iii.i;   }•:•'.<■       •  *•'■    •• 

aiiMiiiit  of  e.\erei-e.  or  halnt.  or  volition,  in  the  utterh 


rue  members  of  a   ooiiiMiunitv  i-ou 


Id 


pOs 


dv  ati 


eel 


215? 


ON    IML    OKKilN   OF   SI'KC  lES 


the  Ktru.'tiirc  (ir  iii-ti^ict.'*  of  tlio  fV-rtilc  menihors,  which 
aioiir  'i-;ivi'  (it'-^(  fill! ants.  I  am  Mirpri^pii  that  no  one 
has  aii .  iiu'ed  tliis  (icrncustrativo  (  i>f-  of  H.-utcr  iuseit.-, 
aj.:a]ii>-l  Iho  woli  kiii>,\!i  (iortriii'    ot  i.aiiiarrk. 

^■'////'/<•,■r7.  I  lia\(' t'h'i('a\  (iiireil  I'i;i't1v  m  tliis  c!iafitf>r 
to  -how  iliat  the  nu'iital  (jualitiiw  ot  our  tiniiu'»tif 
aiiiiiiils  vary,  aim  thai  the  variations  ar«'  inlierit»'fL 
Still  in<ir<'  hriclly  I  have  atti'nijitcfl  to  show  that 
in«-ti!nt-  v.'iry  sli^^litly  in  a  «tatc  of  nnt'ire.  No  one 
will  (ii-piite  that  iiisiincis  arc-  of  tin."  hi^iK">t  iin(,ort- 
aiii-e  to  caih  animal.  1  iien'forH  I  can  >»'e  rin  lilhiulty. 
iiruier  fhaiiLnnj.'  conditions  of  lifo,  in  natiiial  selection 
a<-(  ii'tii;lafinir  -litlit  niodirii-ations  of  instinct  to  aii\ 
extci.i  :n  any  usetul  direi  lion.  In  some  ca.-ie>-  i.alnt 
or  11  f  anil  (Ji-n-c  have  {)roh:i!'ly  con.e  into  jil:;v.  I 
dii  not  |;;-olend  that  the  "act.^  y-i\en  in  this  ch.tpter 
Ktrcn;.n!o.n  in  any  tcreat  ueL"<'e  my  thoorv  ;  hut  none 
oJ  t!io  case>  of  d'llii'ulty,  to  the  host  of  my  jiidL'ment, 
aninhiiasi-  it.  On  the  otner  liand,  the  fact  that  in- 
stincts .ire  ml  a]  way-  ahvdutely  perfect  and  an*  liahle 
to  ni:.-takc';  :-  that  no  iu>linct  h.i^  I'cen  pf  iced  for 
the  cvclu  ive  good  of  oilier  animals,  hut  liiat  each 
ai  inial  takes  achaiita^e  <if  the  in-lincts  of  others  ; 
-  tiiit  the  canon  in  natural  hi>''iry,  of  'Natnra  non 
facil  saltiiiii,  is  applical.le  to  instincts  as  weil  as  t<i 
eoriHireal  structure,  and  is  plainly  cxplicalde  on  the 
foreiroing  views,  hul  is  f>therwise  ii.evplic:ii»le,  :i!i 
tend  to  i-orrohorate  the  theory  of  iralural  -clectiua. 

I  ills  thcorv  Is,  also,  strcntrthened  hy  .-ome  few  other 
fact.-  :u  reijaM  tn  ;n-;tiii''ts  ;  as  hy  that  common  case  or 
clo>ely  aliieil,  hut  certainly  distinit,  spei'ies,  -.vhen  in- 
fiahitii.::  di-tant  ji.irU)  of  the  world  and  liviny  under 
ci'iisideraidy  dit'^Tent  conditions  of  life,  vet  often  re- 
l-unin'r  nearly  the  same  instincts.  For  in-tance,  we  can 
undcr-tand  on  the  principle  of  inheritance,  how  it  is  that 
the  till  ii-h  of  .'^oiith  America  lines  its  nest  with  mud,  in 
till*  .-.iiiif  [•••ruiiiir  manner  as  uo«'s  our  t>riti-ii  ihrusii  : 
how  It  I.-  that  the  i  ale  wrens  (I'mtrlodytes)  of  North 
America,  hiiild  '  coek-iiesU*,'  to  roost  in,  like  tlie  inalas 


Ir- 


INSTINCT 


2iy 


f  iiur  (lUtinct  Kitty-wrens. -a  hahit  whi.;ly  iiriHkf  tliat 
)f  :iiiv  otliL'r  known  !iir(i.  Finally,  it  may  not  lit' a  lni:it-al 
U  liuclion,  liut  to  my  imairmation  il  is*  tar  niort'  <ati,-;a<'- 
'..■ry  to  look  at  <i.cli  in>tini-t-i  a^  the  ynunir  curivoo  eject- 
!j--  it**  tn'.tiT-lirMi.hfr-. — ant-i  making  '•lav»'«,  -  lin'  lar\«> 
>t  iclnHMiinouitli*'  U'criuiir  within  the  iive  hodio  ofcater- 
iillars,--not  as  specially  endowed  or  crfaU'd   instinrts, 

■It  a-  -,],:ill  <-rin-M"ijiieni'es  of  one  ireneral  law,  loading 
•-o  tiip  advaiit  fiin'iit  ot  ail  orj^anic  hoinir«,  nai..r!y. 
->  ult:[)iy,  varv     lel  the  htrouffest  live  aiui    the  weakfst 


i 


<  ii A  1' J  !;i{   \ni 


It 


HYllitlDiBM 

(tJi!!"'-*'- I    '-!vr.,i,i    the  ft.rili'       f  llrst     r.-"<   v.^     .f  '.v-U- 

ve.I  l.y  il-..  ,      .,1-1  aw,  ,'  ,ity 

^i   '■■  r.rility  n  ,t  a  spfcial  >-ri'..\u,rtii,   i.ut  inii.ittnUil 

t^n ''  :i -IS' -rmises  if  th'-  st.rjtx  <■!  (Irit  onis-se*  kn<l 

of  hyr:;-  farull.-lism  \>i->.wfei;  th-  .■(T.-rtii  ..f  r-hanRp.!  con- 
dltl-ns  ..f  life  n,„i  .  p.isii,!..  K-rUlity  .  f  vari.tie*  wlu-n  rr..sse.J 
•ml  ..I  tliiir  ii:..ii-r<-l  rr-prl'iK  ti-t  iinivenwl  Uyt.riils  ami 
n.ougrel*  ••.niparc  !  ii:.iej»-i,  irntly  ..f  their  fertility-Suuiniary 

Ihk  vifw  u't'lit'rally  eiitcrrairu"!  ''v  iiatiir,il;>t^  n  fiiat 
"l^ccic-..  wln'M  nitcriTo-M';,  li:i\i»  licci  <jK'<-i;i:ly  cndo'M'd 
wuh  the  tju.ility  of  stmlity,  ti  urdtr  to  [ircvrnt.  tlipcitri- 
fiisioii  of"  111  ..ii:.i!iic  forms.  Tliis  view  ct'rL-iiiily  ^eeids 
.it  fir>;t  [•robaliic.  for  s|i(Mios  vviti;i;i  tlic  same  fouiitrv 
■tmlii  l;!rili\  have  kept  tii>r!iicl  ha<i  thev  heei,  .  apaMe 
of  crossinL'  tret-lv.  Tlie  iiiiportanre  of  the  fun  that 
h\i.ri(l«<   are  verv   iretierallv   sterile,  ha-,  I    iliink.  Keen 


ht'on^ 


miii'h    umler.'-ate'l    hy  some  late  writers.      On   itif  l! 
')'  iiu!nr(ii  ■>'-i,,tii>n   thr  C'/.v^  r.v  fsfn'nriiii  ivij>i>rtiiut .  uinv- 
rnnvh    <I1    fh*-    stfrjitf^j  iif'  hi/'.ri'lji    t-DUid    not    piisslKly  Kp    of 
nriu  (t(h^:>itiiijp    to    (hrm.   nwi    tlwrt-torp   muni    uot    fun^ 

^>frri     t!(-<jHlrr,l     f,ij     tfif     <;nttinni'/l    J)ris>Ti::;\,,i,     nt'   SIKTfX- 

xirt'  profit'if,.!'  '!iu^feg  of'  xtfriiutj  !  hope,  liowpver,  to 
be  ahie  to  .sh"^v  that  sterility  i-  not  n  -j.e.;.i:'v  ar.juire(l 
oreii(lo«e<i  .|Li,iIit\-.  toit  is  i'!<-idem;il  ou  other  a.'.|4irei) 
■  iii'frences. 

ill  -rea;  itii:  tiii-^  siiii,eit,  two  ri.i>.>cs  ,,>  tuts,  to  a  l.iri^e 
p\'rrit  iiunlaiiieiitaliy  (iiffereiit,  ha\e  L'-i'iien.llv  been  ori- 
foiMi.le.i   toir,.tl,er  ;   iiameiv.  \\ic  sterility  of  two  sju'eien 


HYHIUDISM 


.•21 


when  iir.st  cro8»e<i,  and  the  sterility  of  the  hytjrKi--*  pro 
■l.K  fil  trom  tiiem. 

I'lire  *j>eri»'s  have  of  course  their  orirnrii^  oi  r('[iri>(tui- 
LJoii  ill  .'i  jterft'it  rniniiliuii,  ypt  when  uiterc  r()>se'l  l'ie\ 
iirudijce  eitiier  \\;<^  or  no  otf^princ.  llyliriii-.  ti'i  the 
ittier  haiui,  have  their  re|ir<xlu(  tive  or^r-ins  funciiDnaliv 
liiipdlent,  as  ii.ay  lie  cU'arly  seen  in  the  state  ot  the 
male  element  in  l»uili  [>l.iut>t  and  animal.-.  ;  tiinutrl'  the 
ortraiio  theniM'lve.x  are  perfect  m  struilure,  as  lar  as  the 
!iurrosc<ij)€  r*'.''als.  In  the  firHt  case  the  two  ^exiial 
"lementh  wiiKii  (/o  to  torm  the  ernhryo  are  perfect  ;  in 
;lie  second  cjise  tiiev  are  either  not  at  .lil  'lf\ei<tiH'd.  ur 
are  imperfectly  deveh)peil.  1  ins  distinclinn  i.«  imporUmt, 
wtieii  thecaii^e  of  tlie  sterility,  which  is  coinmon  \n  tlie 
t«<i  cases,  hat*  to  !>«»  cii!i-<iderisl.  I  he  di^iiiiction  iia- 
lir()i>at)i\  heen  sliirr<-<i  ovrr,  owin^  to  the  sterility  in 
..ii'li  cases  heiiiic  loi)ki-<l  mi  av  a  npecial  eiidnnment, 
liesnnd  ilie  priivince  m  our  rea-'oniuir  pov^cr^. 

i  lie  fertility  of  varieties,  that  is  t»t  the  torm..  kno^vl, 
uT  believed  to  have  descended  trom  coriitnr)n  p.irenin. 
wi.en  niterero^sed,  and  like<*i»e  tiie  ferluity  of  their 
;nonL;rel  ()f'"sprin^,  is,  on  iiiv  theory,  of  e<)i-ial  iiiiport- 
a.ice  with  the  sterility  of  species  ;  for  it  -eem-  m  make 
a    iiroad    an<l    clear   distinction    l>etween    varieties   ano 

".pC.   iCS. 

lirst,  for  tlie  sterility  of  species  when  c^o^M■l!  aii<i  or 
lI.c  r  hyltrid  offsjirinir-  It  is  inipossitdt'  to  m'ii1\  the 
-eseral  iiicmoirs  and  works  of  tliose  two  con-^cientioiis 
and  adriiirahle  oi)servers,  Kulreuter  and  <f.irtner,  vvho 
aimosi  devoted  their  lives  to  thin  suhject,  wiihctut  tteiiiii 
(l»'»'piy  impressed  with  the  hijrh  trenertiity  of  some  .Ifirrfe 
oi  -lerility.  Ki  Ireuter  makes  the  rule  univcr'-al  :  i.ul 
the;,  he  cuts  tlie  knot,  for  in  ten  c^i-e^  in  which  ht 
found  two  forms,  considered  ity  most  authors  x-  distinct 
spe'ie**,  quite  fertile  together,  he  unhc^itiititii.'-ly  ranks 
them  as  varieties.  G.'rtner,  al»o,  makes  the  rule 
e.iu.iliv  universal  ;  and  he  dispute*  the  entire  tertilitv 
of  K  'ireuter  s  ten  cases.  But  in  these  and  in  many 
other  cases,  (iartner  ib  ohlieed  carefully  to  count  the 
•ie«ii,,  ill   order    to   show   tliat   there  is   any  detfree   of 


222 


ON    INK   ORKilN    OF   s|'K(  IKS 


wteril'tv.  Ht'  always  ronijirircs  thf  nirixiiinini  ii'irnh'-r 
of  >-P( 'i-*  yirndiicci]  Ity  'w..  ^jifvie-  wIumi  <T(is«cf|  mid  hy 
tliPir  ]ivl»ri(!  nfV-prin;.'-,  witli  tli«  averai^o  iiiiin!i»*r  pro- 
(liKTil  l»y  liotli  jitirc  jiaront-sporira  in  a  stiite  ot  iia'.ure. 
Iiiit  a  K»*ri(»ii;i  cauH*  (iT  <Tri>r  =f<'iiis  to  mo  U)  }<o  ]i»'re 
introfii!«»«(l  :  a  |»laiit  to  n*'  Iiy'»ri<iiM'(l  t;iii<1  In*  castra^p*!, 
aTiii,  wliat  is  oltrii  nmrt'  in.itortant.  niii^it  l>e  ^«'r!ii(l»»d 
ill  DriltT  to  |!rM\  cut  jidllfri  'ifMntr  liroiitrlit  to  it  !iv  n^»'rt« 
!r(jin  othor  |il:iiit.'i.  Nearly  all  tlic  plants  ox|»<»rimpiit- 
iscd  on  l>v  (iirtiior  wore  pottod,  aii'i  apparentjv  \<f>re 
kopt  iti  a  <'liaTnl'»>r  in  liis  hou'^o  'f"!:at  ili'^«<»  prf»<"f<sp« 
;ir<>  nfU'i;  in ■'] riuw  'o  tdo  O-rtilitv  of'  a  ii'ant  (•a!:not 
'■I'  <iuiriit<'ii;  for  'i'TtinT  l;:'.  ("J  in  li'-  s.uii'  .■i'>i'-ir  a 
-core  <;♦"  ca^  f>  of  plants  wlm-ii  lif  ca^lratoil.  and  rtr-tili- 
■•iaM\  fpr1ili-''d  «itli  tlipir  o^vm  poi!i"i.  ami  («'x<'liidintr 
-i'l  ("ISPS  r-uili  as  tli'»  l/pcruniinosa',  in  ulijch  tl.prp  is  au 
irkno\v]'"^::pd  ditri-'ull v  in  tin'  Tnanipula'ion)  li.alf  of 
' Vii  st>  tiN'Piitv  plarit-  lia»i  \\<<'\r  ffrti!;t\-  in  some  (Ipjtcp 
unpaired.  Morco.  cr.  as  ( J  ,r»nt'r  iJurir^iT  Bc^t'ral  vpars 
rpppatcdl\'  ij"os>t'd  tlip  priinrosf*  a;id  (ri\v>!i[),  whicli 
wp   ha\o   sindi    o-fKul    reason    to    i^clMnp   to   t'P  \aript'»'s. 


and 


oi:]'.'   'iin'c    ur    ♦"Aii'p    >Ji|.v"Pi'ii('i!    in    irPtlinLT    fprtilp 
sfi'd  ;     a.^    ho    found    tiic    roniTMon    red    •;;i(|    iijiip    piin- 


pf'iicl-;    (AiiaL'';iilis   arxcnsis    and 
l'»'-t    Uo{ani-t-<   rank 


coTnlt'.i 
,1. 


as  \arii'tips,  a'lsolutt'lv    -UTf:*-  to 

iTP'lipr  ;  aTid  a"-  in-  caiiu'  to  tlip  Kame  coii.'li  -loi  in 
sovcral  otliei'  .maloiro'is  t*ris.>s  ;  it  stH'm-  to  riir  tliat 
wp  u\uy  M  'II  hp  pcrinittfi!  to  doulit  wiictlior  many 
"tliPr  --jP.'icv  are  rrall'.  "o  stprilp.  wnen  inter. rnssed, 
■IH  ( i.irt  IMT  'ndio,'.  es. 

It.  1-  pertain,  oji  tlip  onp  hand,  tliat  *}ip  sterility  of 
\ anions  spp<'ii'«i  when  prossed  is  po  {!!''^rreet  in  (ie>.-r<'t* 
aiid  frradnatps  a'-v-»v  so  insensildv,  nnd .  nu  tlie  otjipr 
hand,  that  tlip  fer'ilit}'  of  piirp  sjiecips  \^  -ii  easily 
a'ipetpd  !)y  '. ari(»ns  pireunistancps,  that  tor  all  f>rartiral 
purposes  it  is  inn>t  ditlieult  to  say  w'lprp  [iprtect  fer- 
tility en.ds  and  stPrility  hetriiis.  I  ihnik  no  lietter 
•  '\  !,|pn<"»' oi  thix  c-an  he  rp<juirpd  than  tliat  tlio  two  most 
•'\p"r;>Mie('fl  ohsprvprx  who  havp  c\«'r  livpd,  namely. 
Kolreiiter   and    tiartnpr.    slionld    have   arri'.  p<i    at   <lia- 


nvmunisM 


'''n 


.  1 


•notrii'nllv  ojtj>f>«it»>  r<)7ii'lu-<i(>Ti>   iit    ri'mni   to  the  very 
-.".;.♦'  sjtfc'.p.       It  ;s  :il-«t  ino.>.t  iii^lnn'tive  »<•  •  >  i> — 

|i\t   I    li.ivp  in>t  sjiice   )icrp  to  piittT  oiMir'ii  "vj- 

dfic*'  adv.iiMM'd   l.y  our  l/cst  l)olai:isU  o'  "u 

wliftlicr  rcrtain  (iduhtful  f<irni««  kIioiiIcI  iiv  r.r.i>^>->'.  ,(s 
<j>t*<'i»"<  or  varif'lips,  wi:li  tlie  evidonre  tVimi  Jt-rtility 
■i(i«luc-e'l  }iv  di'l'Toiit  hyWridiscrs.  f>r  hy  tlif»  .iih»  anitior, 
T'l  fxin'rinxMi's  nia«i<'  d^rinir  <iifTer«Mit  ytar)».  It  can 
1^  l)0  ^!lll'AIl  that  !i»MtliPr  sterility  nor  fertility  atftml.H 
1  i\  ill  '  (li-liiMlioij  l»elHoe!i  spenos  aiul  ^  irieties  ;  but 
(  it  tht'  oviiiniic  from  tiii-;  ^ourcp  i.'Ta(lii:it«'>  away,  and 
i- (iou'ttnl  ill  fhtxHuu' <lf'u''rpp  as  \n  tlu»  evidoiire  derived 
■rii;ii  (it'cr  cnn-titiitinnal  and  stnuinral  riilifnTices. 

Ill  r.'uir'i  to  iIh'  stiTilitv  of  hyliritjs  in  >--iicif's-;ive 
■j.iH'ratioii^  ;  tlinu^rh  (J  irliicr  wa«  piialilod  to  rear  <ome 
)i\  iirids,  I'arct'iily  trtiardiiitr  tlicrii  from  a  rross  with 
.I'htT  jturc  {i.iront.  for  -'\  or  «(>vtMi,  and  in  one  casp  ror 
■f    t;o!if>r:i!iiii>,  yt't  be  :i-t'rts  jio-^itively  tliat  their  fcr- 

•  I'tv  never  iinTciseii,  hut  trtMi'-rally  trr-'ally  i:(>(rea-;Oii. 
I  (lo  not  lii.ui't  lliat  ihis  iy  usuaUy  the  ea-p.  and  that 
•hi'    terfilitv  oi'ten    ■.uiiiiflily  decr.a-e-.    in    tho   fir<t   fo'"^ 

[  ciifraMoiis.  Nevertlielos-;  I  Ix'iieve  th  it  in  nil  tlievo 
er[vf'rii!ients  tlic  fertility  has  lieen  iliniiiii-hed  !^y  an 
ii:(leTieniie;it  caii-ie,  namely,  fr<  'ii  e!n-e  :;if er'ireed'iiir. 
I  l:av(«  eolicited  so  lar::*'  a  hody  ot  tact-,  shownii.'- 
•1  it   olo-c   iiiterlireediiiL'    lps-en«   tortilitv,  and,  on   the 

■tiier  liaiid.  thai  aii  (u-<-asiot!al  cross  wivh  a  di-tiiict  in- 
cjivid'-al  or  variety  mrrca-^es  fortility,  t!;at  !  caMiol  douht 

h"  eorrprtiu'-^  oi  'liis  ahiei-t  iini\<T-al  heKel  amonu''Ht 
l.f.ders.      li.  toid-;    aro  ^(.'ldonl    r:'.i-»'d    hy   experiim-n- 

•  ili>f.s  111  en'at  ii'itiihpr»  ;  and   a>-  the  parpiit-sppeies,  or 
.♦tier  allied  livhrid^.  L'eierally  ;:row  ii.  the  sariH>  trarden, 

the  visil>  of  insert-  niu-t  he  careluliv  prexented  during 
tpo  floweriniT  sr-nson  :  henre  hyhriils  uill  ironeraliy  U> 
i!  -tilised  diiiinir  eaidi  treiieration  hy  their  own  indi- 
vi.liial  jiollt'H  ;  and  I  ani  eonviiu'ed  that  l)ii-  would  ho 
in  'irioui  to  their  fertility,  alrerniy  le«.-erii'd  *■;  tl  eir 
iivttriii  or'^rin.  i  am  s!retiu'Uii'"<''i  '"  ''■■'  «."inituou 
Iiv  a  riMiiar»watiIe  statement  re]>ea;e<i!y  niad»»  l»y 
(iartner,  namely,  tl.it  if  even   the  le^ss   tertile  hyhrids 


f/.' 


224 


nV   THK    ORI(,IN'   OF   SPKC  IKS 


li<«  .'irtiiiiMiIlv  fcrtili-o'l  with  !:\l)ri(I  |MMlfii  of  tlie  same 
kind,  their  trrl.i.ty,  imlvvil  ti- t.iiuuiii:  tin*  fn-ijuput  ill 
elte(  t>  ol  tn.iiiijiiiiatioii.  soTiiiM  !iii»'>  tU'cHUMliy  iiiorr.is«'S, 
arid  <;ot's  on  iii'T('.i«i[ii:  Nnw,  m  .iriM.i  i.il  IiTlihsjiiiuii 
((iiUfii  is  a-«  iiPt'ii   taken    hy  ciiance  la-  I  know  from  my 

■  i.vu  ex[tenenrf)  Irnrn  the  aijiher>  ol  aiii»rlitT  liower,  as* 
i.iim  ti,,>  antlier.-'  ot  tiie  linger  it-oif  wliiidi  is  to  he 
lertiii-i'd  ;  so  that  a  rro^^  iietwi-en  t^o  iloner-,  thoiii:h 
prtduid  .  oil  the  Name  phinf,  would  lie  thu-  Htieitt'd. 
Moreiiver,  whi'i.fViT  (<i.'n))licated  evperitufnts  are  m 
proure"!-*,  so  iMretiil  an  ul-server  an  ii  iitner  would  h  ive 
M>traled  iiis  h_\  i>rid-,  aii'l  thi^  would  iiave  uisuixmI  in 
earli  trfiif'ralioii  a«rossHiih  a  poih'ii  from  a  di.-t'iict 
fuwer,  eitticr  iroiii  liie  same  jdant  or  Irom  another  plant 
u  tiie  K.i!iie  ir,  hnii  nature.  And  ihu-^,  the  >'  raiii^e  Jailot 
the  Hicre^'i^e  of  fertil.ty  in  the  sin ce-sive  jreiieralions  ot 
iirtijuiiii/y  i>-rtuistii  hyhrid-  riiav,  I  heiieve,  he  accoiinted 
tor  h\-  clioe  interhreedm^  .ia\:nij  heeii  avoided. 

Nir.s  let  us  ti;r;i  to  the  r«'-iiils  arrived  at  hy  the  third 
nio-i  ev|itrienci'd  h\'liridi-«'r,  naiiieh',  the  Hon.  and 
Uov.  \\  .  lieriiiTt.  i  ic  1^  as  e!n|i!:atic  III  Ins  fonidusion 
liiat  some  livi)rids  are  perfect!)  Jcrtiie  a-s  fertile  as  the 
,in;-e    parent -^pO'■ie■-      a-    are     Ivdreuter    ami   (.i.irliier 

■  .lat  >uine  (iejree  ot  sterii.tx  lie;.\een  di-lii.it  sp»>cies  is 
4  iiii:\er>ai  ia"A  o!' nature,  lie  eiiicrinitaiived  on  >oiiio 
ot  tlie  \er\  same  ^pe.  ie^  a.--  did  d.irtner.  I'he  d.iter- 
enee  in  tiieir  re-iill'-  rt.ay.  1  tlnnk,  he  in  part  acrounu-d 
for  i»\  iierherts  trreat  fior' u  ul;  ural  -kiii.  aiid  hy  ins 
ha\  inir  hotii(iu>es  at  hi-  iMiiiiinand.  * 't  iii>  maiiv  iiii- 
]ii>Mant  staU-fuents  I  will  here  irno  only  a  sii:.:le  one  as 
a'i  exaniph',  namely,  tint  ••e\ery  o. nh-  iii  a  pud  of 
<.  rniurn  i-..'i(:i^e  fertili--ed  l'\'  (  .  reNoI'i!  irn  produ''eii  a 
plant,  \*iiicii  Uie  say-^;  I  never  vaw  to  uv.  ,.,  in  a  i  a^o  ui 
It-  natural  teiund.iiion.'  So  that  \vr  i.ere  tii\e  perfect, 
or  even  more  tiian  commonly  perteii,  icrtiiify  m  a  first 
cro>-  liet'.verii  i\\o  di-tiiicl  speCie>. 

I'll!-  ca-e  of  the  (  riiium  leads  nu-  t<>  refer  to  a  most 
smj'iii.ir  ;.!;!.,  nam»i\,  tnat  iiier<>  are  uiur.  .titiai  plants 
of  I  crt.iin  species  ot  l<<dielia  and  of  -oine  otiier  t.'tnera, 
wbu'ii  can  t>e  far  more  ea-iiy  fertiliseu   ii\   liie  ptdlen  of 


HYBRIDISM 


22d 


another  and  distinrt  >;ppcie.s,  tlian  bv  their  own  jiolltMi  ; 
and  all  the  iiidi\  l(ilI,^',^  of  ii»*arly  all  the  spofios  of  llip- 
piM-trijin  M'tMD  to  In  in  this  j»r«^dira.iuMu,  lor  tli»*?;o 
iiKints  liav»'  Ikm.'ii  foutnl  to  yi»'ld  mm'(I  to  flu*  |i'il!.'ii  of  a 
;ii'tiiict  >|K'i  ii'-,  tlioii;;li  <jiiito  stcrilt'  witii  tl'T  own 
liolh'ii,  iiotwitli-tHiHlini;'  th:it  flifir  owii  |M>llcri  \v;w 
rniiiid  to  lie  jM'rft'itiv  irood,  tor  it  fcrtili-^jMl  distinct 
-J.... ■!(•«.  So  tlial  rcrtaiii  iriili\  iiliial  plant-  ami  all  the 
VI  li\i(liial>  of  certain  specie-  can  ;irtiia!l\'  i'e  h\liri<li-ed 
micli  more  reaililv  tlian  the\'  can  l>e  x-lf-fertili-ed  I 
I  i>r  instance,  a  hulhof  llippca-t  mm  anlicurn  producetl 
f 'ir  tinners;  three  were  tertiii-cd  hy  llerhert  \Mth 
ih'ir  own  polleti,  and  the  toiirth  \vas  «.uh-e(jur:itly 
f.  rtili-ed  hv  the  judlen  of  a  coinpmiiid  h\l»rid  de-cruded 
:r(i!i»  tiiree  other  and  di-tiiict  -jiecies  :  the  re-ult  v^as 
that  *  tlie  ovaries  of  the  three  fir-t  fhiwer-  -oon  <'ea-ed 
'n  ''r(n\.  atid  it'tcr  a  u>\y  das-  [leri-lu'ij  eutireh',  whereas 
til''  pod  iinjinuii  iteil  by  the  pollen  of  the  hyliriil  made 
\  ii^i'Toiis  irrowth  and  rapid  proijress  to  inatiirily.  :iv<\ 
III. re  trood  seeil,  whi<h  veiretate<l  freely.'  In  a  h  'ter 
'i>  iiic,  in  li'.Mt,  Mr.  llerhert  tohl  me  that  he  had  tlieri 
nu'il  the  experiment  duriui;  five  years,  and  he  con- 
;;niied  to  try  it  d'uinL''  -everal  >;uli-e;;ieiit  \ears,  and 
ilwavi  with  the  satne  result.  I  hi-  r'e-iilt  has.  al-n, 
K'cn  (.intirnied  hy  other  ohscrvjTs  in  tlie  ca-c  of  Ilip- 
pi'ri-truii  A-itli  it-  -iit>-L''eriera.  and  in  t!ie  c;i-e  of  -orno 
lit!  IT  ^renera.  as  l/)he!ia,  l'a-.-iiiiira,  and  \er'>isciim. 
.\lthMMt;li    the    plants   in   the-e    experiments  iMicd 

per.'cctlv  healtliv  and  althmiirh  hoth  the  o\u:c-  and 
p'lUcii  ot  the  same  lloucr  were  j>erfectly  t:ood  uitli 
re-pei't  to  other  -pecies,  yet  as  they  were  tiinctiunally 
imperfect  in  tlicir  murnal  self-action,  we  must  intt  •• 
that  the  plants  wi-re  in  an  'innatural  -tate.  Ne\''rtht*- 
It's-  the-e  facts  -how  0:1  »hat  slii'lit  and  mysteritm- 
can-es  the  leaser  or  trreatei  *'ertility  of  -pei-ies  wlien 
cro--ed.  in  comparison  with  tru  same  specie- w  iien  stdf- 
fertilised,  >-ometimes  depeml.s 

i  he  practical  evperiinei'Ls  -f  tujr^iciiltunsts.  thoiiyh 
not  made  with  scientiiic  preci-i  ui,  «'•  s^-rve  -ome  notice. 
It  is  notorious  in  how  eoniplit  'tod  a  uif-.  iier  the  speeiea 


220 


ON   TIIK    OKI(;iN    OK    SI'K(  FES 


lil 


of  l't'I;ir_'.>iiiiiiii.  Tilt  li-ii.  (  ulrodl.iria,  IN'tuiiia,   lUifxlo 
d«Mi.in>!i.    ctr.,    liri\»'    i't-rii   crnsvcl,  yd   in.iiiy   «)f  tlicse 
hyliri'l^  M'l'.i  tii't'h-.      I  itr  itist;irn-«'.  llcrJ-crt  .T^^tTtx  tliat 
a  livliriii  tVnm  (  .ilrcolari;*  iiitt'irntuli.i  .iiHl  plaiitatriiica, 
vjMTU'-.   iiMi't    \n'if!\    i!i--irMilar   in   l'i-iht.iI    liitut,    '  re- 
prcxlu.  .'i|  it>fll  as  j.frfc.tly   a-   :t   it    hail  l'i'»>!i  a  natural 
sMfif's   tVotii   |)ic   iinMiiitaiiis  of    (  iiilt'.'        I    )ia\o   takiMi 
«ii't.<'  11  ilii-  In  a-fcrf.iiM    tin-   <l<';:i-(<'   uf  fcrlilitv     it"  sciriie 
1(1    till'  cotMi.lcx    rru-sf-  nt'  |{ Ii'mI. nirii'lroii-.   ami    I   am 
assiiro'i  that  tiri!i\   ot   thi'iii  arc  |(rrti-rll\    tcrt;lt'.        Mr. 
(  .  NiiMi'.  Iiir  I'l-taiicc    i'i;uri!i>-  nic  tha'  !if  rai»i'<  -storks 
for  tr  rail  in:.'-   troin   a   hvhriil    hft\\i'«'n    KImhI.    I'untiriKii 
anil  t  ata«hnMi-f.  arnl  tliat  thi-  li\  IiphI    "s..,'.!,  a-   trcrly 
a-  It  !■.  posvihlc  to  iniaLMni'.'      II  nl  li\  hrnl-.  whfi  fairly 
tn>.i!i''l,   f'lni'  nil   ilfinM~iML'  in    l'i"-tility   in    <'aih    mic- 
(•i-.,i\o   L'l'nr'a;  mn.   a-"  <iir1nfr   tH'licvr-  to  hi-  tlic  ra-o, 
till*    fart    uiMild    ha\t'    hi'fii    iioforioii-    to    nnr^.-rv  rniMi. 
f !.)!-tiiM;lturi«t-   rai-i>   1  irL'f   ImmU  ot   t'lf    >aint>    hyhriils, 
■ind  -iirli  aloMi-  arc   fairly  treatt-d,  tor  iiy  iu-t-rt  aL-'f'ncy 
the  M'\("-al  iniiividiiaU  of  thi'  «;arn«>  li\hiiil   variety  are 
alloucii    to    fri'i'lv    cro-i   "ilh    cai-li  othi-r,  ami    the  in- 
jurious   iiitlui-iK-i-   of   clos,.   intt'rhrci'ilin;:    i-«  tlius  pre- 
Ncntt'il.      Anv  one  inav  rcniily  ronvimc  tiinisi-lt  of  the 
ctlii-iiMicy   of  insert -aufni'v    hy  exaniiniiii:    the   flowers 
^,^'  the    iiiorc  stcrili-    kimh    of   hyliriil    riiiMiiMiemlrou-i, 
whiili    proiiiii'f    no   imljcn,    for  he    will    tiinl   on    tlieir 
•-!iunia>;  (ile'itv  of  }>oIleri  hrout'ht  from  other  liowers. 
In    reL'-inl   to  animals,  iiinrh  feuer  exjierinient-  have 

) II  caretiillv  trie-l  than  witli  iilants.      It  our  systematic 

arran:.'-eii;eiits  can  he  trusted,  that  i<  if  the  t-enera  of 
animals  are  as  lii-.tinct  froii!  earh  oiher.  as  are  inetrenera 
of  plants,  then  we  may  inter  tliat  animal-  more  m  iilely 
M-parat.il  in  the  s'-ale  of  nature  can  i>e  more  easily 
iTosst'd  than  in  tlie  case  of  plants  ;  hut  the  hyhrids 
themselves  are,  1  tliink.  more  sterile.  I  doulit  whether 
anv  case  of  a  perfectly  fertile  hybrid  animal  can  lie  coii- 
sid"'ed  a<  thorouirhlv  well  authenticated.  It  should, 
liovse\er,  lie  home  in  mind  that,  <»wniL'  to  tew  ainmals 
hrc'-.linir  fn'elv  under  contiiiement,  few  experiments 
have   iieeii    faiilv   tricl  :   for  iiisUmce,  the  canary-bird 


HYHUiniSM 


227 


li.i"  Immii  rro>«>-»Mi  with  nine  otli<>r  fiiiclio>,  l>iil  h«  ii(»t 
otif  <•!  llu'-f"  iiiiii'  ^jit'i'ij'x  iirf«'(i«  fri'«'ly  iti  ronMn'inriil, 
^i  have  iKi  riu'iit  t<>  rxjieit  that  iht-  tir«.t  «Tn«..-.»'>  i»«<t»«tH'ii 
ihfiti  and  ih»'  (.mars,  ur  that  ihoir  liyhrifi-*.  >liiinlii  '•»• 
j.rrtVrflv  f«Ttil.'.  .\;:.i!!i, '»ith  rc-p^Tt  tn  the  (Vrtilils 
ri  Mii(«'»i\<'  L't'iHMati(iii>  (it  the  iiinrt'  t»»rtilr  h\hriii 
iiiitiials,  1  hardiv  kiii>«  nf  an  iii-tainc  in  «}ii<ii  t\vi> 
aiM;lu*>  ol  the  sjinu-  liyhriii  havj-  I>»m'1i  rai>-<"<l  at  the 
-  riif  titiif  from  diirtTcnt  p  irt'ii'.'-.  »<)  as  tu  .inml  tlio 
'!i  »'tf(Mt>  ol  rl(ist>  iiit»'rhr«'fdiiit:.  ' 'n  th«'  (i(iitr.ir\ 
•  rnt h«Ts  ami  -i-tiTh  ha\t»  usually  beon  it<»*>»m1  hi  rarh 
-. net-oil. e  L'tMifiatiKU,  in  npjiositioi;  tu  th«'  cnti-tantiy 
rf|'i'at«'d  ailtiii>iiitli>n  «it'  v\rr\  )ir('»-d«'r.  Ami  in  tlii> 
. •.!-♦•.  it  1-  not  at  all  surnri-iiL'  that  lin-  itihcrt-nt 
-triility  in  th«'  hyhrid-  -houid  iia\e  ironf  on  incri>a>int;. 
.1  Ml-  \M';f  to  act  thii-.  and  pair  hn.iht'rs  and  si>t»'rs  in 
•iic  <a-i'  lit'  anv  pun-  anuiial,  wiiicli  Croni  any  cans** 
i, ni  tilt-  ha-i  UMidt-nt  v  to  stt'rility,  thf  hri'>-d  would 
a--i.r»'dly  I'O  lo-l  in  a  \t'ry  Irw   j/f ii('rat;o:i-.. 

Althouirh  I  do  not  liiiow  of  any  tiiomiijhly  \v«'l! 
ai.tinMiticated  ta-t-  oJ'  pfrtVctly  t'tTtiU'  iiyiiiiil  aniinal->, 
1  havft  sonu'  reason  to  h^Iiinc  tliat  ih«'  hylind"*  tmni 
(  irviilijs  \;i:rinali>*  and  Ht'e\f<ii,  and  from  I'h  i-.anus 
...lrhiin>  vMtii  I'.  lon|uatiis  and  with  l*.  M-r.-itolur  ar«r 
■-Tlfitlv  t'lTtiU',  'llu-re  is  no  doiiht  that  tin  ~»-  thrr«i 
1  ;i»'a>aii't>,  nanu'l) ,  tin'  ••omrnon,  the  true  rin^^-netkod, 
.iii':  !lie  Jajian,  inti-rcross,  and  an-  ht'iomimr  hlcniU-d  to- 
;:i-t!n'r  in  the  woods  of  several  parts  of  Knifland.  The 
l,\liri<is  fniiii  the  ronimoii  and  ChineM'  uee^e  (A. 
r',:;noide-),  s|ieries  which  are  so  ditferent  tliat  lliey  are 
_-e:Mrallv  rani<ed  in  di-;tinct  jjenera,  have  olten  hred  in 
liii-  I'ountry  with  either  pure  pareiil,  and  in  one  -intrle 
ui-fance  they  ha\e  hred  intir  .vc.  Thi-  wa>  eHerfed  I'V 
Mr.  Kvtoii.  who  raised  two  hyhriiU  from  the  -aine 
parents  h  ;t  from  different  hatehes  ;  and  from  the>e 
luo  ldrd>  he  rai>ed  no  les>.  than  eii:ht  hyhri(U  (trrami- 
I  iiildren  of  tlie  pure  iree  >)  from  one  iie-t.  In  lm,.a, 
iiowever,  the'-e  iross-iired  i:ee>e  niii»l  i>f  iai  Inore 
fertile;  for  I  am  assured  li\  two  eminently  rapahle 
juiltre>,  namely   Mr.  liiyth  and   (  aptain    Hutlon,  that 


22fl 


ON    IHK    OFtrcilN'   OF   8|'K(  IKS 


^' 


>#hoI«  flork»  f>(  tlie-**'  fros<«'<|  yrr^o  irt*  kofit  in  vKrimi- 
part"  ot  till' ((iiinlry  ;  :iti'l  .is  tht'V  arc  k»'iit  f'ltr  prdfit, 
wlioro  ii»'itln'r  [nir*'  |>.irt'iit--|)f>'i('s  ('xi^tf,  they  mii»t 
r.Tt.iiliI  V   1>«'  ll!iriil\     •'••rt:'ii'. 

A  (liM  tr;ri«-  wiricli  m  .ciimU'il  \*itli  l'.ill.i>,  li.u*  t>«'f»ri 
lartrt'ly  /irccyiti'  1  \<v  ntiMlern  ii;itiir.ili<t«»  ;  iiHtiwly,  tlint 
nu»Nt  III  (II ;  <l(imi».tic  ;iiiiTn;il-  \\;\\"  fi»«>i-i'iiii«'ii  fVotn  two 
or  tnori'  ^»iiil  -i»i'<ip»,  since  n»iinii;iiu'l»'<i  t»y  inu-r- 
rrossirit;.  ( 'ii  tins  kii--.v,  tin*  .•iliori;:iiiil  -nn'rirx  r  -i-t 
eilliiT  lit  iT-t  li;ivc  iiDiilurcl  ijiiiU'  fi^rtiln  hytirid^,  or 
till'  liyliri.l-^  iiiu«t  }i;ivf  l.fcMtiii'  in  >.iili-i'i|u»'tit  jfi'iuvi- 
tioiH  <|wili)  tVrtiU'  iiii'liT  liouH'stnvitiiM.  I  li;s  |.-»!»»'r 
altiTiiativi'  »iM'iii-«  to  iiii»  tlic  nmst  jiroiiiliii'.  iini  1  .irn 
:iitliii('  I  to  lii'Iii'ii"  ill  Its  truth,  ;tllh<Miirli  it  r»'-ts  on  nn 
(lircrl  i'\  iiii'iirc.  I  hcl'.",»'.  tor  iiHtanrp,  tliat  our  <h>irs 
have  ih'-v.iMiili'd  from  -f.crai  vvjhl  <tcM'ks  ;  vt .  with 
[MTliaji-  till"  t'xi'rptiuii  ot  rcit.ini  inilhTnnus  (iomc^tir 
lioirs  of  >oiith  AniiTiia,  all  :iri'  (|uitc  i»>rtil«*  toiri-thcr  : 
ami  ai;il'i;\'  ni.ikt's  mi'  jrca'l}'  ihtuiit,  wlicthi-r  the 
•.(•vi»r;il  ahi.ri:,'iii  il  -|ii'rii'v  nu  lid  at  hr>t  liav«»  trci'ly 
lirt'il  toLTi'tliiT  ami  li.avc  |iri«ilu.'C(l  .juiti*  fi-rtili'  tiyhriils. 
So  ;i.'-aiii  thiTc  i>.  ii'a>.on  to  h<'!i('\i'  that  our  lOiropcin 
ami  thf  liiitntii'il  Imliaii  ••attic  art' ijuitc  tiTtih' ti'ii-i-thi"- ; 
liut  trmii  tacN  iiiiiniiiiiiiratfil  to  iiii'  hy  Mr.  Blytli,  1 
tliiiik  thi-'.  iiiiist  hi' con-MliTt'ii  as  di-timt  >pi'ci«vs.  On 
Miis  \  icw  ol  !  ii(>  ori^'in  of  iikuiv  of  imr  <ionii'--tii' animals, 
we  iiiii»t  I'ifhcr  tri^i-  up  tli('  i"'lii't  oj  the  aliiinst  ii:i!- 
vi'r-..il  -!■■  iiity  of  (li^tim't  s|ii'cii'-  of  animals  when 
(TO— ('(i  ;  or  we  nui-t  look  at  sterilitv.  not  as  an  in- 
ih'lilih'  ■  h  iiii-teri-tic,  hut  n-  one  eapahle  of  heinp 
reiiiiiM'd  hy  (lumr^tication. 

I'iii;iil\-.  lookinir  to  all  tlie  a^rertaineii  :att-  t<\i  tin' 
inti'rcro*-'!!:^  ot  plan's  and  aipmals,  it  iiia\'  I'e  i oncliided 
tliat  -.oine  ilejTci-  of  ^terilit\.  h"th  in  first  crosses  and  in 
livhriil-,  i>  -in  evtremely  ireneral  result  ;  Imt  that  it 
cHTUio! .  nnder  our  present  >tate  ot  kno«  ied^'e,  he  con- 
sidered as  atiMilutelv  tiniversjil. 


Ijiirx   govfrniiiii    (hf   Xrri/ity   of  first   t'rosxt^s   and   of 
lli/hrids.-  We  will  now  consider  a  little  more  in  detail 


i  : 


HYHHIDISM 


22l« 


th«-  nrcumfUiticfv  .-ukI  rule-  iin\et:]iuii  tii.'  ^.tonlify  ol 
tirnl  cnisscH  ami  ut  h\  Itrids.  <  hir  thiet"«>lM«'<-t  will  \>v  to 
see  whi'tluT  or  not  the  ruU-  iii<lir;itp  tliftt  -jtf .  if  h.ne 
*}.«•«■. alU  li»'»'n  omluwr.l  witli  tlii-  iju.ility.  iti  onlfr  to 
{•recent  thnr  iTo-o-inr  ami  lilemlintr  locetlier  in  uttor 
I  "ii^ll^il>Il.  I  lit'  ttiiidv*  iin;  rulr-*  ami  tooi  bi-ioiix  .irf 
I  I  t  tiv  <ira\*M  ii|»  t'toin  (iirtner-  a«liriiral>lf  wirk  nii  \ho 
lij  |jrilii<^atio!i  ol  |)i.uit>.  I  have  lakt-ri  njiuli  |.aiiiH  to 
i"'«'rtaui  how  far  the  nil<'?<  ajii'ly  to  animals,  ami  con- 
-.  .»T.j.ij  Ik'W  M-aiity  our  kriowieil;;*'  is  in  rrirartl  lo 
h\ti!.ii  anmipJ'*,  1  liav«'  Immmi  siirjin-fd  to  tiiid  lio4» 
iTfiiiTallv  tin*  !*amf  rules  ajiplv  to  Ifotli  ixiiii;tli'm-. 

It   lia-j   l.«MMi  already   remarked,   ttini    the   (le::ree    of 
t.Ttihtv,  h.tlh   of  hr^t  t  rirfsfH  and  ot' h\,  hrnl  •>,  tradua-.e-f 
liHin  zero  t<>  ;>f;If»t  fertility.       It  i>  «i!rjir)-ii.L'  in  how 
i!i.i:iy    curioii'*    w;ivj4    this   tjrailation    ran    l>e    'hitn!i    l<i 
f\''t  ;   hut  oi'lv  the  tinre^t  outline  ot  the  fart-  tnti  'uere 
Si«  ifiven.       \\  iit'M  [lollen  from  a  plain  or  due  tamily  .h 
].]  i«ed  on  the  <lii.'nia  of  a  idant  ot"  a  diMiiict   tannly,  it 
('\erts  no  more  iiiMiieine  than  "o  much  inoriranic  dii-t. 
Iroin  this  ai'soliite  zero  of"  fertility,  the  jiolien  of  differ 
.  lit  "iKcies  of  the  same  L'enus  aiipiied  to  the  >ti:.Mna  of 
-ome  «»ne  sperie",   yields   a    perfect    crailation    in    th» 
in:.'. her  of  seeds  jtrodured,    up  to  nearly   complete   or 
even  <juite  complete  fertility  ;  and,  as  we  ha\('  seen,  iu 
trtain  ahiiorm  il  tia-es,  even  to  an  excels  oi   fertility, 
he\oiid  that  v^hil■!i  the  ].!aiit  n  own  pcdien  will  produce. 
r  •>   in  liylirids  them-ehes,  there  are  soine  wliiili  np\er 
l,.ive    pn,,!,  red,   and    pruhaSiy    ne\»'r  would    proiluce, 
even  with    the  pollen  of  either  pure   parent,  a  ^'inl.'le 
teriile  seed  :   hut  in  some  uf  tiic-e  la-es  a  tlr.-t  trace  of 
lertiiily  may   he  tieteited,  hy   tlie   pollen  of(uieofthe 
jiure  parent-species  cau»insr  the  fiov.er  o?  the  hyiirid  to 
-^iher  earlier  llian  it  other'.vi--e  would  li.i.c  duiic  ;  and 
'he  earlv  vuthering  of  t he  flower  is  «ell  known  to  lie  a 
-  irn   of '  iii'ipic'it     fertili-ation.       From    this    extreme 
:ci.Toe  of  sterility  we   have  self-ferr:ii-eil  hvliriii-  pro- 
duciajr  a   ^rreaier  and   K^oater  numher  of  seeds   up  to 
lT:e<-t  fertility 

Hybrids  from  two  Bpecies  which  *rc  .ery  difticuit  to 


2,30 


ON   TUE   ORKJIN    OF   SPE(  IKS 


cro<w,  and  whi<-li  rnrolv  proHiico  ariv  off^jiriiifir,  are 
K-enerally  very  ^iU>rile  ;  Imt  tlie  parallfli-in  li«'twccTi  tlip 
'iirtii  iiltv  of  niakiiiiT  a  tirst  cross,  ami  llio  storility  »t  flie 
hvuriil^'  thus  product-fr  •  two  cla.-st's  of'  fait'^  *hi(h  ire 
i,'»*in'rallv  contuunilt'fl  Uiir"'lior  :■<  by  no  m<vins  stri-t.. 
I  lnT»!  ar»»  niaiiv  cast-s,  in  v  incli  two  p'lrj'  Hpt-ni-y  •  iii  he 
Hinted  witi'  inui.iiial  fa<-!lity,  ;»nd  iwm.J'ko  uunifrourt 
hv(irid-'i!T-.,>rinir.  Vft  tln'-e  )iyt>rid-i  ire  'fniarKa'dy 
«terilt'.  < ''I  tlie  nt!;er  liaiid.  there  are  «pei-ies  '-vliKdi 
ra!j  We  (•r<>--.eil  verv  rarely,  or  witii  ertreine  diificulty, 
lujt  tlio  tiv'Tids,  wlien  at  last  prodin-fd,  are  very 
fertile.  Kven  within  tlio  lirnita  ot'tlie  same  irenu^,  ror 
instamo  in  Di.itilhti.s,  these  two  opt(o--ite  ciL-es  oii-'ir. 

I'lie  tertility.  Ixith  nt' tir><t  rrosM's  ari'l  ot  hybrids,  in 
more  easilv  atfectefi  by  iinfavoiirabie  coMilitio!;-.  tlian 
is  the  I'ertiiitv  of  pure  sjMMies,  Kiit  ttie  deu'ree  ot 
fertility  is  likewise  irniately  variable  ;  tor  it  is  not 
aN.i\->  tiio  -aine  when  the  s;iTnc  two  sjHM-ies  are  eros-ed 
'ludiT  the  ^arne  eirciunstanees,  but  dei>ends  in  [iirt 
upon  tlie  fonstitiition  of  the  individwals  whieh  hayij'fn 
to  have  been  chosen  for  the  expernnent.  ^«o  it  is  wi«h 
bybridw,  for  their  detrreo  of  fertility  is  often  found  in 
differ  (jreatlv  in  the  -everal  individuals  raised  from  seed 
out  of  the  -ame  eapsulo  and  exp'ved  to  ex:\ctly  tlie 
same  cotiilitions. 

Hv  Uu"  term  svstematie  affinity  i»  meant,  the  re>ein- 
blarice  between  spet-ies  in  utrueture  and  in  lonstitution, 
more  e-pe<  i.illv  in  the  structure  of  parts  wbicli  are  (jf 
hiirh  pliv-iolo^'iral  imjmrtance  ai'.d  *hicli  diib'r  li'tlo  in 
the  allied  species.  Now  the  fertility  of  ririit  crosses 
Vh'tweeii  spe4'ies,  and  of  the  hybrids  produ<ed  from 
them,  is  lareolv  iroverned  by  heir  systemauc  atfinity. 
Ihis  is  clearly  -liown  l)y  hybrids  never  having  been 
raised  between  species  ranked  by  systeiuatisLs  m 
dUtinct  famlien  ;  and  on  the  other  band,  by  very 
closely  allied  speeies  generally  uniting-  .tith  fariiity. 
Hut  the  oorre«iK)ndenco  between  systematic  affinity 
anil  the  f:i4-ilitv  (d'crossiin;  is  ()y  no  means  strict.  A 
multitude  of  cases  could  be  eiven  of  very  closely  allied 
B]>ecies    which    will   not   unite,   or  only   with    extreme 


HYBRIDISM 


2.31 


dilfiiMiltv  ;  and  on  the  other  hand  of  vpry  distinct 
)in'ci«>s  whirli  iiiiit»>  u  itli  the  ulni(>>t  facility.  In  the 
s;tnie  fHriiily  thfie  may  W  a  tr*Mius,  a.s  Dianthus,  in 
which  vtTv many  >j.c.  ies  tan  Tni)>t  r»»a(iily  l>e  iTossvd  ; 
fuid  aiKitli.T  -t'l.iis,  as  ^lit-iic,  in  whirh  the  most 
i.prst'vcriii!.'-  ethirts  }ia\H  taiU'd  to  [.rodiico  h»'t\MTn 
r\lr«'nicU  ciuM'  >|.ofi««.>.  a  single  hyt>nd.  Kv»mi  vsitliiu 
tl.o  limit's  of  tho  <iino  e»-inis,  we  nu'ft  with  tlii^  -ame 
.lirteri'tii-e  ;  Inr  iii>Uincf,  the  many  s|)e«ii's  of  Nicotiana 
have  i'l-en  more  lar;r»'ly  .-n.-i-od'  than  th.'  species  nt 
ihnost  aiiv  iitiicr  irenus  ;  '■ut  (iarfntT  tumid  tiiat  N. 
aciiininara,  v^il;cil  is  not  a  particularly  distinct  si.ecien, 
ohstmately  faUed  to  fertiii-e,  or  tr»  he  fertilised  hy,  no 
ie«s  tliaii  eitrlit  otlit-r  sjie,  les  nl  Nict)liana.  'very  many 
ai'alotfous  facts  could  he  iriven. 

No  ftiie  has  lieeii  ahle  to  point  out  what  kind,  or 
what  amount,  of  diiiereiice  in  any  recnjrni>ahle  cliar- 
acter  is  suriicient  to  prevent  two  species  erossiiuf.  It 
can  he  hliowu  that  plants  most  widely  ditfereiit  in  hahit 
and  ireneral  appearance,  and  haviiitf  strongly  marked 
ititlereuces  m  e\ery  i)art  of  the  Hower,  even  in  the 
i.olleti,  in  the  truit.  and  in  the  cotyledofis,  can  h« 
crossed.  Annual  and  perennial  plants,  deciduous  ami 
evertrreen  trees,  plants  inhahitini^- ditferent  stations  and 
!itte<l  for  extremely  diiierent  cHmates,  can  olten  l»e 
crossed  with  ea^e. 

Uy  a  reciprocal  cross  l»et"fen  two  species.  1  mean  the 
ca-e,  lo'  in-tance,  of  a  stallion-horse  heinir  first  cros^eii 
wth  a  female-ass,  and  then  a  male-ass  with  a  mare: 
tlipse  two  ^pec1es  may  then  1»«  said  to  have  heen  recii>- 
rucaily  cro»e«i.  There  is  often  the  wide-t  possible 
dii'erence  in  tlie  facility  of  makiiijr  reciprocal  crosses. 
J^uch  ca^es  are  hi^rhly  important,  for  they  {•r(»ve  that 
the  caj>acitv  in  any  two  species  to  cross  js  ot\en  com- 
pletely independent  of  tlisir  systematic  affinity,  or  ot 
any  reconni-alde  ditfcrence  in  tlieir  whole  onranihation. 
(  >ii  the  other  hand,  these  ca.ses  clearly  show  that  ihe 
c.ipacily  for  cror;>in>f  is  cOuucetcti  With  eiJiie-tit'-itM'-f-'i, 
diiferences  impercepiihle  hy  us,  and  confined  to  the 
repro<luctive  system,      lliis  diifereuce  iu  the  result  of 


1 


2n2 


0\   THK    ORIGIN   OF   SI'F/'IES 


I  1  ■ 

hi 


r»'i  i[)r(ic.-i!  (TO^i-i's  l>«'tMe«Mi  tiit^  >.irii(«  t«o  >{)Pf.es  wa^ 
loiJL'' MiT'i  (i(i-('i'vi'(l  hy  Knirciitor.  In  t''i^<' an  :ii>itaiiop  : 
.Miniliili<  jalajia  ran  cavils  he  N'rtili.-<'(i  liy  the  pnllcn  nf 
M.  Iniiifillora,  and  tiir  )ivliri(l>  thus  pr(i(l!|i'c  i  .ire 
sii!ii.ii'iitl\  f'rrtili- ;  liut  1\  Iii-iitrr  tried  more  t!i:.  .  t'.vtt 
liiMnlrcd  time-,  (lnri;;i' ci^lil  i<il!o\\  iiiir  voars,  t»>  ftTliiise 
rt'i'i|irncally  M.  iDiiL'.lli'ra  .\itli  l\\v  |h)1jpu  <ifM.  lalajia, 
and  Mttcrly  tailed.  ><'\»Tal  other  fi|'ialiy  -trikiiit:  *'a^e!- 
ndihi  1h'  iJi^t'n.  Thiint  ha.'-  i)h-i']\ cil  the  aaiiie  ta<"t 
with  I'ertaiii  -<'a-;N I'i'ds  ui-  I'lici.  (i  rtacr.  iiir)re'j\er, 
Iniind  tha!.  this  difierenet'  .4"  facil:t\  in  luakinur  re- 
(•i|>riMal  rr<i>>es  is  exlreriiely  •  nminnn  in  a  h'--<er  decree. 
He  lias  (iliservrd  it  e\eii  helueen  f'urrns  >n  « h(s»dy 
rolated  (a^  MatUiirda  annua  and  trhihraj  tliai  many 
lM»taiii-ts  rank  ihein  only  as  varieties.  I',  i>.  al.-o  a 
n'lnarkahle  fact,  tliat  hybrids  raided  from  reoiprocal 
cT(»->es,  th(Hi::h  ni  tour>e  i-dinpoiinded  ol  the  very  same 
two  species,  th«  one  sj)pcies  lia\  iiiij  first  heeri  used  aa 
tiie  father  and  then  as  tlie  mother,  t'eneraUx  ditler  in 
fertility  in  a  small,  and  oicasioiially  in  a  hitrh  deirree. 

Several  other  singular  rules  could  lie  tfiven  from 
(iartinr  :  lor  instaiH  i*,  some  species  ha\e  a  reniarkal.lt; 
power  of  c-ro-sin:r  with  other  s|  ec  ie.>  ;  other  >p"cies  of 
the  same  jn'iius  have  a  remarkalde  power  of  impres.sinir 
their  iikci.ess  on  their  hybrid  otrsprinir  ;  hut  the>-o  two 
powers  do  not  ar  ;ill  m^cessarily  ^o  t<i:rethpr.  There 
are  certaiii  hybrids  which  instead  of  havinir,  a.-'  i.s  usual, 
an  intermediate  character  between  their  t^To  parents, 
always  cli)~v''\-  re^eiiille  one  of  them  ;  and  .such 
hyhritls,  thnui^h  externally  so  like  one  of  tln-ir  pure 
parent-~:>ecies,  are  with  rare  exceptions  extremely 
steiile.  So  aiT-iiii  amontrst  hybrids  whi(  h  are  ■isiially 
iiitci  II  ••di.ile  in  structure  between  their  parents,  ex- 
ceptional and  abnortiial  ii'riividuals  sometimes  are  bnrii, 
whii  h  clo-ely  resemble  one  of  their  pure  narents  ;  and 
ilie^e  hvliritis  are  almost  always  utterly  ^teriie,e\  en  when 
the  iitlier  hybrids  raised  from  seed  trcm  the  siinie  capsule 
have  a  coiisideraide  det^ree  of  fertility,  i  iiese  fads  show 
how  ((mjpletely  fertility  in  the  hybrid  is  indepeiideut  of 
its  external  resemhbnce  to  either  pure  parent 


P- 


h 


^^3» 


,V  i': 


^\:>v^ 


HYDRIDISM 


233 


("oiisiilrT  intr  tiu'  -Ji'viTal  r\i\(^  now  sri\pn.  whitli 
(.'•vprii  tho  lertilit;,  of  ur>i  cn^-sos  and  (it'  hy'hriiis,  ue 
-;c('  tlia*  wlu-n  forms,  whiili  inust  iie  •  i-iisuiorfd  :i^  tr<'0<i 
\u<\  iii-t;nct -[io<-it<,  art-  luiited.  tlieii  UTtility  t:r:>il nates 
t.iiir  zero  tn  ;'>'r!('i-t  f»Ttility,  or  even  *o  'Vrtilit)  iimU^r 
'•■:,;. in  (Moiditiniis  in  ex>"t'ss.  'Hiil  their  fertility, 
I..'-  (ic*  lifiiit/  t'Diuit'iitly  -.u-iccptil'le  to  Livourr-i'le  and 
i.i.i:i\(iur,iiik'  ton.iuiiiri-i.  is  iniuitcly  \:in:ild»\  i  iiat  it  i« 
\i\,  nil  means  aUvavs  ilu-  siinie  in  d»-i.Tee  in  tlie  fir-t  rros.s 
ciiid  in  the  liyiirids  jirraliu-ed  from  tiiis  tnivs.  '1  liat  the 
t.rtility  ot  hyl>rids  is  not  rehited  to  the  ilr;:ree  m 
*liich  thev  reseiii.ie  in  cMtrrial  appearance  either 
parent.  And  lastly,  that  liie  facility  ol  making  a  hr^i 
ini>s  between  any  two  specie-'  i--*  not  always  t'o^erned 
I:.-  their  systematic  aff.nitj  or  de?ree  of  re>enihlancr  to 
i  icli  (ither.  Thi"  latter  ^titcment  is  elearly  proved  hy 
toiipt'ical  cros'-e.s  hetween  llie  same  two  species,  |i»r 
,111  ordiiijr  as  the  one  sj»e(  ies  or  the  other  is  used  as  the 
I  ither  or  the  motlier,  there  is  generally  some  diiTer- 
tiie,  and  occasionally  the  widest  po^^illIe  diiier  nee,  in 
!.c  facility  of  effedintf  a  union.  i  he  hyhrids,  inor» 
<:\i':-,  pro<iuced  from  reciprocal  crosses  often  differ  in 
i'ertility. 

Now'  do  tliese  complex  and  sinjrular  rules  indicate 
t'i.it  species  have  lieeu  endowed  vv,th  sterility  -imj.Iy  to 
I  .event  their  hecomintf  confouiHicd  .n  nature.'  I  thuilt 
I  it  For  why  nhuuld  the  sterility  he  «o  extremely 
(1  liferent  in  detTee,  when  various  species  are  cro.s,se<i, 
,  M  of  whicli  we  niuj-t  suppose  it  wnuld  he  ♦Mjually  im- 
p'litaut  U)  kt»  p  from  blenduitf  to^^eiher.'  W  ity  should 
tiii'  de^rree  of  sterility  he  innately  variable  in  the  in- 
dividuals of  the  same  specie.-.'  \\  hy  >hould  some 
species  cross  with  fa.  ihty,  and  yet  produce  v.tv  sterile 
h\  tirids:  and  other  sperit^scro^s  with  extreme  dithculty, 
and  yet  produce  j'aii  iy  fertile  hybrids.'  Whyshould  there 
f'tien  be  so  trreai  aditierence  m  the  rejiult  of  a  reciprocal 
cu>ss  between  the  same  Iwo  species .'  ^V'hy,  it  may 
tM  II  tie  asked,  has  the  produeliuii  of  hyonds  Dcen  per- 
n.ilted  :  to  ffrant  to  species  the  Bperial  power  of  produc- 
ing? hybrids,  and  then  to  stop  their  furtlier  pro(>»^tiou 


n^ 


';<"i~; 


^-  ^*::-'r;; 


•'i.a^;^:/.^:i-£Si.  'J'.%    i     &--M 


••k'^ 


1^2 


m 


w 


234 


ON   THE   OIlI(;iN   OF   SPECIES 


ill 


\>y  (litfoHMil  (ietrroes  of  >t»!rility,  not  -iriitly  r(>l.•^^<•d  to 
the  facilitv  nf  the  first  union  lielweni  their  jiareriti*, 
ec('ni><  to  l>e  a  str.iiiire  arr.'iiiirenu'iit 

I  tie  t'oreiroiiitf  ruN^s  and  fVii  t-,  dm  'hi-  othtT  h;iii<i, 
-ipiie.'ir  to  rue  I'U-.iriy  to  iiiiii'-;i;t'  th.i'  tlie  -iteriiitv  tioth 
of  iir^t  i-ro>v('>  aiiil  ot  ii,liri<i<i  in  sinijilv  iiicnitMital  or 
liept'tuieiit  on  inknown  ilirf:>rence<.  i-liu'lly  in  the  r»'nri>- 
rliictive  xy-^N'tii-;,  ol  the  '^jiecie-i  wliirl,  -ire  crosvod.  I  he 
•litTereni  es  'nitiif  ot  >io  peruliar  hihI  liitiitt-d  ,i  nature, 
'iiat,  in  re"i[iroi;il  ir<>-M-s  'letwfrn  t«o  -pi'ii*'^  flie  ni.ile 
«<;xu;il  f'li'iiien!  of  tlic  one  \*ill  nffjMi  tVi-elv  act  on  the 
tetnale  scxu-il  i-i.'nifnt  of  Hie  mMut,  hit  riot  in  a  re- 
versed direction.  It  «ill  lie  advi«.aide  toexplini  a  little 
more  ttiliv  l>v:in  example  wliat  I  mean  hy  sterility  ')ein(r 
incidental  on  other  ditVer*»in'Hs,  and  iii't  a  •"piM-ially 
endowed  qualitv.  As  the  cajiacity  of  one  plant  to  be 
ifrufled  or  hudded  on  anotlier  i^  >^o  erjtirely  unimportant 
for  it^  weli.ire  in  a  staU*  of  nature,  I  pre-ume  that  no 
one  will  >-iipp,we  that  tiiis  capacit)'  is  a  "jifi-iuHy  en- 
dowed i|u.ilitv,  !>Mt  will  a<lmit  that  it  is  imidental  on 
differences  in  the  haws  of  trrowlh  of  the  two  plants. 
\\  u  can  ■.ornetimeH  so«  the  rea-*on  vvhy  "ne  tree  will  not 
t.ike  on  ah  1. 1  her,  from  diirerences  in  their  rale  (d'trro-*  th, 
in  the  hardness  of  their  wood,  uj  the  period  <d  the  flow 
or  nature  of  their  sap,  etc.;  hut  m  a  multitude  of  cases 
we  can  i--i^'n  no  rea-on  wh;ite\er.  Oreat  liiversity  '\\\ 
the  -iize  of  t^o  plants,  <»ne  heintj  woo<iy  and  the  tdher 
herhaceous,  one  lieiii;^  e^cnrreen  and  flu-  other  de- 
ciduous, and  .idaptation  to  widely  different  cliniates, 
does  not  alwav"  prevent  tht^  two  f^raftinu'-  toilet  her.  As 
ni  hvi'ridisiif :on,  >o  vvith  trraf'tinj.',  tlie  caitacity  in 
limited  hy  sv^tetnatic  atrniit\ ,  for  no  one  ha-  heen  ahle 
t»)  trratt  trees  'ouelher  h«  ionirinir  to  (piire  <li->tinct 
familiesi  ;  and,  on  the  other  hand,  tlosely  allied  species, 
and  varieties  of  th"  same  species,  can  usually,  hut  not 
invariahlw  he  irrafted  with  ease,  liut  this  capacity,  as 
\n  hyhriilis.ition,  is  hv  no  means  ahsolutelv  K'overned  hv 
Hystematic  affinity.  .Mtluuiffh  many  distinct  ^'eiiera 
within  the  same  family  have  been  trratted  to;rether,  in 
other  ci>es  species  of  the  same  ^,enu»  will  not  take  oa 


HYBRIDISM 


235 


each  other  'Hie  j»par  can  l>e  irnifteti  far  more  r^ailily 
on  the  '^'iitire,  wIip  h  is  ranked  a.-*  a  dixtinct  ir»«miH,  than 
on  the  ipple,  which  is  a  niemher  ot"  tlie  same  jrenii.H. 
Kveri  <iitirr»Mit  v^riotie-s  ot  tlie  pear  t-ike  with  different 
dejrrees  of  facility  on  thequinre  ;  so  do  different  varie- 
ties of  the  apricot  and  peach  on  certain  varietiej^  of  »}i« 

•ilum. 

As  (JirtTier  found  that  tliere  was  soinetiiiie-*  an  innald 
difference    in    different     in  'ii'^duch    nt    the    saino    two 


apecies  m   (  ro-^sui^  ; 


•«o  SaL'aret   believes  this  to  he  the 


case  with  d'r?erent  individuals  nt  the  same  two  specie* 
in  Vieinif  jf  rat  ted  tcirethor.  A-s  in  reciprocal  erns-es,  the 
tacilitv  of  efi'ectiuij  an  union  is  nftfti  very  far  from 
e'lual,  so  it  sometimes  is  in  trraftinu'  ;  <lie  common 
jrooseherry,  for  iiiitanre,  can-  t  he  g-rafte<l  on  the 
currant,  whereas  the  currant  \*ill  take,  thouifh  with 
difficultv,  on  the  pooseherry. 

We  liavo  seeti  that  tlio  stflnlity  of  hvhrids,  which 
have  their  reproductive  ortranu  in  an  imperfect  con- 
dition, in  a  very  different  case  from  the  difficulty  of 
uniting-  two  pure  species,  which  have  their  reproductive 
or:-ans  j»erfect ;  yet  these  two  distinct  cases  run  to  a 
certain  extent  parallel.  SomethinjT  analoirous  occun* 
in  irratlinjf  ;  for  lliouin  founil  that  three  species  of 
Kohinia,  which  seeded  freidy  on  their  own  nM)ts,  and 
which  cnuhl  ^>e  srratted  with  no  irre-.at  d  fticuity  on 
another  spe.  ies.  wlien  thus  frrafte<l  were  rendered 
harren.  I  >n  the  other  hand,  certain  specieji  of  >^orhus, 
wht>n  erafted  on  other  si)ecie«,  yielded  twice  as  much 
fruit  xs  when  on  tlieir  own  roots.  We  are  reminded 
!)y  this  latter  fact  of  the  extraordinary  case  of  Hippe- 
rv'^trum,  i,*)!telia,  etc. ,  which  <«eede<l  mucli  more  freely 
when  fertil>'«<l  with  the  pollen  of  distinct  species,  than 
when  s«'lf-fertilised  with  tlieir  owti  pollen. 

NVe  thu*  sw,  that  althouirh  there  in  a  clear  and 
fundamental  difference  between  tlie  mere  adhesion  of 
^r;i!te<l  stocks,  and  the  union  of  the  male  and  *"emale 
elements  in  the  a«*t  of  reproduction,  vet  that  there  is  a 
rude  deirree  of  i>arallelism  in  the  results  of  jrraftintf  and 
of  crouHUi^  distiiHt  specie!*.       And  as  we  must  look  at 


I  i 

i  I 


Hi 


23(! 


ON    I  HE   ORIGIN   OF   SPEC  lES 


th»*  ciiriuiiB  aii(i  coniplcx  laws  jroverriinjc  tlie  facility 
with  which  irtM's  can  he  i.'r;ilLe<i  on  eJich  otiier  ;is  in- 
cident.il  on  unknown  (iirlcrencoH  in  their  vfirt-tafive 
fy.-lt'iiis,  ^()  I  ht'iieve  tliai  thi-  still  more  connjln  lawn 
^ovcrniMir  tlic  tin  liity  ut  lir>t  cross***  are  incijeiital  on 
.inkiiowii  (iiilVrencfS,  chicfl)  in  their  repri»uuiti\e 
•iy>.'.'Mis,  I  ht-f  (iiiicr»'nco>',  in  hoth  ras^s,  follow  to  a 
teruii  Hxtont,  its  iniiiht  have  ln-fn  e\|ii'i  ifij,  systen.atic 
ahiinty.  nv  wliith  «'\pry  kiu<i  of  re>enihi.-i!,re  and  dis- 
Biniil.irur  t)ctwcen  urtranic  hoin^s  in  altcrnftteti  to  he 
ex[ir('sHe«l  I  he  hi' ts  tiy  no  niean:i  KCt-r  .  to  me  to 
1  idirat»»  tlint  ih(  j^reater  or  h-sser  difiu  Uily  ot  «v.ih»'r 
^raitii.j;  or  croK^inff  lojrcthor  \arious  spct  iph  Iiju'  heen  a 
siteciai  f»n<iowineut  ;  altiioiipli  in  the  can©  of  cni-tsinjf, 
tli»*  (i.tfu  ulty  i>*  an  imp<iri.;nt  for  the  endurance  and 
Hi.ihiiity  of  sjtecihc  form.-,  as  in  the  rase  of  ^^aftiuJ{  it  ia 
uunni»oriant  for  their  welfare. 

('anxfii  of  the  Strriiity  of fimt  i'romes  and  of  Hyhridn. — 
We  may  now  hiok  a  little  closer  at  the  prohahle  causea 
of  the  sterility  of  first  crosses  and  of  LyhridH.  'Hicse 
two  ca>es  are  fundameutally  dirfereut,  for,  as  iust 
remarked,  in  the  union  of  t«o  pure  specien  the  male 
and  feinaie  sexual  elements  are  perfect,  whereas  iu 
hyhiiiU  ihcy  afe  impertect.  Even  in  fimt  crosses,  the 
ercalcr  or  h-^er  diiliculty  in  effecting  a  union  aj>- 
pareaily  defteuds  k.iu  ^everal  dist>mt  lauses.  i'liere 
i.uif.t  sometimes  l»e  a  phy -ical  impossihility  iu  the  male 
clt'iiiciit  reaching  the  ovule,  as  would  he  the  ca>e  with  a 
I'i.tnt  havini,'  a  [d^til  too  ioiiK  for  the  poileu-tul)c-.  to 
reach  the  ovarium.  It  has  also  been  observed  tliat 
wiien  poilen  of  one  s|>ccies  is  placed  on  the  stiirnia  of  a 
di'.uiictly  ailied  sjtecio,  thoui:h  the  pollen  tube«  pro- 
trude, they  do  not  i>e:ietrato  the  sti^matic  surface. 
AtThin,  tlie  male  eleiiuut  may  reach  the  temale  element, 
but  he  incapaiile  of  causinsj;  an  embryo  to  bo  dt  veloped, 
ttji  aiipniM  to  ha\  e  been  the  ciise  with  some  of  i  buret  s 
experiment*  on  Kuci.  No  explanation  can  be  ^-iveu 
of  these  fact«,  any  more  than  why  certain  trees  cannot 
Xtv  ^aft«d   on    others.      I,A8tly,  an   embryo   may    be 


M|r^£^J 


HYBRIDISM 


237 


developed,  and  then  perish  at  an  enrly  period.      llih 
latter    ;ill/»r:iativo   has   not    l>oen    "ufTiciently   ;itt^n(1pd 
to  ;  but  I   t"*lievp,  from  o!i>»»>rvations  roniniumiat*<1  to 
mo  by  Mr    H«'witt.  who  haH   had    trrfat   oxporieTire  in 
liybridi-iinjj  rallinaceoux  hirilH,  that  the  parly  death  of 
•}i'>  f-mhrvo  i'i  a  vory  fri'<iiie!:t  raii«p  of  ^ter.lity  in  first 
•Tos-ies.    '  I    was  at'  fir<t   very   unwillintj   to  U-lievc   in 
•'lis  viow  ;  a.-!   hybrids,  when  once  borti,  are  irenorally 
hcalthv  and   lonjr-lived.   a-  ^c    -o<»  in   the  case  of  the 
..iminon  miib>.      Hybrids,  howe^or,  are  ditfcrtvitly   cir- 
.  umstaiiced    before  and    after    birth  ;   when    Uirn    and 
hviinf  in  a  country  where  their  two  parents  can    live, 
■iiPV  are  jrenerallv  placp«i  under  suitable  conditiotis  of 
,1'e.      But  a  hybrid  partaken  of  only  half  of  the  nature 
i:iil    constitution   of  ita   mother,  ami   therefore   i)efore 
'..rtli,   *.•<   lontr   as   it   is   nourished   within  its  mother's 
nomb  or    within    the   eea   or  seed    produced    t.y    the 
•Mother,  it  mav  he  exposed  to  conditions  in  some  (leirree 
i!:-uita!.le,  and  conseiiuentlv  be  liable  to  peri-h  at  an 
lily  period  ;   more  especially  as  all  very  younir  iK'iiiir>' 
(■'■•n  eminently  sensitive  to  injurious  or  unnatural  con- 
iitioTjs  (if  lifo. 

I;i  reirard  to  the  sterility  of  hybrids,  in  whicii  the 
-e\ual  elements  are  impenectiy  de\elopHd,  the  case  is 
.  erv  ditferrnt.  I  have  more  than  once  aflrdcd  to  a  larpe 
.  .d'y  of  facts,  which  1  ha' e  collected,  sli,)\vir!L'  that 
•A hen  animals  and  plants  are  removed  from  their 
'  .I'liral  conditions,  they  are  extremely  liable  tr)  have 
iicir  reproductive  systems  seriously  ntb'cted.  This,  in 
'i-t  is  tlie  trreat  bar  to  the  domestication  i>fa!!imals. 
H. 'tween  the  sterility  thu-  -uperinduced  and  that  of 
':\brids,  there  are  majiy  points  of  similarity.  In  buth 
ca^es  the  sterilitv  is  imiepeiident  of  ireneral  lieiilth,  and 
1'  often  accompanied  by  excess  of  size  or  trreat  luxuri- 
;iiicp.  In  both  ca-sps,  tlie  sterility  occurs  in  v.-irious 
'icL^rees  ;  in  both,  the  male  element  i-  the  most  liable 
to  Ke  .-iffcoted  ;  but  sf)metimes  the  female  more  than  tlie 
male.  In  both,  the  tendency  poes  to  a  certJiin  extent 
with  systematic  affinity,  for  whole  croups  of  animals 
and   plant.s    are   rendered   iminttent    bv  the  same   un- 


2.38 


ON   THK    ORir.IN    OK   SPE(  IKS 


I 


natural  conditions  ;  and  whole  groups  of  s[»erie«  tend 
to  produi-e  sterilo  hyJiridn.  On  llio  othtT  h.ind,  one 
Hpefios  in  a  ffroup  will  Koniptinic>>  r»'-i-t  t:rwil  chanj^es 
of  conditions  willi  uninn>airt'd  fi-rtility  ;  and  certain 
species  in  a  trroiip  will  produce  uniiMjally  fertile 
hybrids.  No  one  can  tell,  till  In-  tries,  whether  any 
[(articular  animal  will  hre»'d  under  conlin«'tneiit  or  any 
exotic  plant  seed  freely  uniler  culture  ;  nor  can  he  tell, 
till  he  tries,  whether  any  two  species  of  a  jreiius  will 
produce  more  or  less  Kterile  hyhrids.  {.a^tly,  when 
orjfanic  Iteintrs  are  jdaced  duriii  seNcrnl  L'cncrationH 
under  conditions  not  natural  lo  tiicm,  they  are 
extremely  lialile  to  vary,  wliich  is  due,  a-  1  Udiove, 
to  their  rej»roductive  systems  havintr  lieen  sp«'i  ially 
atTected,  though  in  a  lesser  de;jree  than  «hen  sterility 
en^^ues.  So  it  is  with  hvhrids,  for  hyhnds  in  successive 
generations  are  eminently  liahle  to  vary,  ase\ery  experi- 
mentalist has  ohserved. 

i'hus  we  Hce  that  «hen  org-anic  hein;r>  are  placed 
under  new  and  unnatural  conditions,  and  when  hyhridft 
are  produc»'d  hy  the  unnatural  crossiiitr  of  two  species, 
the  rejiroductive  system,  independently  of  the  ^'^eneral 
state  of  health,  is  ariected  hy  sterility  in  a  verv  similar 
manner.  In  the  one  case,  the  conditions  of  life  have 
heen  disturhed,  though  often  in  so  sli;:ht  a  detfree  as  to 
he  inapprecialde  hy  us  ;  in  the  other  ca-e,  «»r  that  of 
hylirids,  the  external  conditions  have  remained  the 
Kiime,  hut  the  ortranisation  has  hcen  di-'turhcd  hy  two 
ditferent  structures  and  constituti(»ns  havini'  heen 
hlended  into  one.  For  il  i.s  scarcely  possihle  that  two 
organisiitions  should  he  coni|>ounded  into  one,  without 
rtome  disturhanco  occurring  in  the  development,  or 
periodical  action,  or  mutual  relation  of  the  dilferent 
jiart,*  and  nrtrans  (»ne  to  another,  or  to  the  conditions  of 
life.  N\  hen  hyhrids  are  aide  to  hreed  i;i/cr  ac,  they 
transmit  to  their  otfsprinir  from  generation  to  fjene- 
ratidii  the  same  compouniietl  or^^anisatiou,  and  hence 
we  Tieed  not  he  surprised  llial  iheir  steriiily,  tiiouf;ii  iu 
some  de^free  variahle,  rarely  diminishes. 

It  must,  however,  he  confessed  that  we  i:atuiot  under- 


HYBRIDISM 


239 


ptand,  exceptiuK  on  vatjue  hypotlieses,  Hever&l  facU.  *ith 

resj.<H-t  to  the  sterility  nt  hy!»rids  ;  tor  iii<taiu-e,  tlio  uii- 

P<juiil    fcrlilitv    of   liyhrids'  produi-ed    from    rprij.rocal 

rro-s('s;or    t'lif    iiirreased   stirility    in    tliose    h>hnd9 

v^liuh   orcasionallv  and  exi-«'ptioiiall\    re>«'inl>l«'  •  lo-ely 

.-itlier  j.urP  pan-ii't.      Nor  do   I   prct.-nd   that  ihe  fore- 

j-oirit:   remarks  yo  to  the  root   of  thi-   niattt-r  ;    no  ex- 

[.laiiation    is    otirred    why   an  ortrani'in,   wlirii    jdaced 

iiiiU'r  unnatural  (•..n.lit!oi:«,  is   reiuh'rtMl  sterile.       All 

•hat  1  have  attempted  to  show,  is  that  in  two  oases,  in 

-oine  respeit.s  allie.l,  sterility  is  theeommon  result,      in 

I  he  one  case  from  the  conilitions  of  lile  haviiiL:  heen  dis 

turhed,  in  the  other  ca^e  from  the  organisation  havinj< 

heeti  disturU'd  Kv  two  oreani-at ions   haMni.'  l>e«>n  rotn- 

l»..uiide(i  into  one. 

It    may  seem  faneiful,  hut    1   Huspect   that   a   Mtiular 
parallelism  extends  to  an  allied  yet  very  diiierent  rlags 
.,1    tails.       It    is  ati  old   and   almost   univer>.il    helief, 
t.iunded,  1    think,  on  a  con.-iderahle  hody  of  evidence, 
that  siitrlit  chanL'Cs  in   the  condilinii.s  of  lite  are  hene- 
l.rial    to  all    livintr   thintfs.      U'e   see  tins  a.led   on  hy 
tirmers  and  trardeners  in  their  fre-iuent  ex.  iiaiiires  of 
seed,  tul.ers,  etc.,  from  «»ne  soil  or  climate  to  another, 
Liid  iiack  a;:  lin.      Durinir  the  convalescence  of  animals, 
wf  plainly  .see  that  L-^real  henetit  is  derived  from  almost 
any  chan'ue   in   the  hahits  of   life.      A^Min.   t...th   with 
plants  and  animals,  there  is  ahundant  evidence,  that  a 
cross   hetweeii    very   liistinct    individuals   of   the   same 
vpt«ies.  that  is  het«een  memhers  of  diiferent  strains  or 
suh-hreeds,  trives  vi;r,uir  and  fertility  to  the  ort-.printf. 
I    hciicve.    indeed,    from    the    facts    alluded    to   in    our 
fourtli  chapter,  tiiat  a  certain  amount  of  cro-inu  in  in- 
ili>pensahle  even  with  hermaphrodites;  and  that  cl..->e 
■  nterhreedintr    continued    durui^    several    p-neralions 
i..t\M'en   the   nearest   relations,   especially    if  the-e   he 
Kcjit  under  the  s.ime  conditions  of  life,  aUays  induces 
wt'.ikness  and  sterility  in  the  progeny. 

Hence  iL  seeing  tnat,  on  i:-v  uiic  li.^n'i,  r::^!.v 
cliatiires  in  the  conditions  of  life  henetit  all  or^'anic 
Iteiiiffs,  and  on  the  oliicr  hand,  that  blight  cross**,,  that 


,'i.:rffe.. 


."sSi^S^K^.ttt'^ilA 


240 


ON   TflK   OIlKilN   OF   SPECIES 


la  crfH«pv  l)(»tw«'eii  tlie  m.iU's  aiiM  ft'niaipi  of  tlio  ^ame 
•iptM'icJ  wl:ii'i  hnvo  varit'd  ami  it'cotTU^  »Iirhtly  'lif- 
ffrciit,  L'i^*'  viroiir  ami  tVrtiliM  'u  flic  nifvpriiiif.  I{iit 
wo  |ia\»'  sifri  that  ifrt'ater  iliaiiL'i''*.  or  .  Iiaii:re»  "f  a 
particular  nature,  ottfii  rRiider  (iriraiiif  hciiiirs  in  somn 
'ioi^rct*  >t«'ri't"  ;  arni  tliat  trrt-ater  tr<>-"«'^,  tli.it  i<  .t"-^''-* 
Sc'wiMMi  inalcM  and  tVm  ilo  whi-h  lii\e  Konnie  wi<l<'!y 
or  specifnally  (litlort'iit.  jir«»<i'i''o  >iyliriiU  whifh  are 
L'f'it'r.i!! V  «t('ril»*  in  sonu*  il<':rrec.  I  catimit  I»or^ua'io 
my-t'lf  t'lat  this  parallt'li'-iii  !s  in  aniiiiMit  oran  illusinii. 
h(il||  ?t  1  ii's  of  facts-  s«'»'in  to  1m>  cititU'ctiMl  t  I'tlu'r  hy 
somp  cofinnori  l>ut  ntikiKm-n  lioii'l,  ^iiich  i~  -sentially 
rolaUvi  to  the  principK'  of  life. 

Frrtiiify  of  I'urifth  s  irli^n  rrnsMff^  ,nifl  ot'thi-ir  Mtni'irfi 
ojfxpriii^j.  —  It  may  !»♦»  uru'^fil,  is  a  iT'.ost  fori  iiilc  art^ii 
mcnf,  that  there  must  he  -tmi"  e  sential  flistinetioii 
hetweeii  -jicrio>  ami  varieties,  au'l  thai  there  must  he 
woiiie  error  in  all  the  foretroitiir  remarks,  inasmuch  as 
\arieties,  however  much  they  ni.iv  differ  from  each 
other  in  exfcrna!  a|»j)earance.  cro-s  with  perfect  facility, 
and  yield  perfectly  fertile  otf-priii:;.  1  fwlly  .admit  tli.it 
this  is  almost  in\aririlplv  the  e.'ise.  But  if  we  look  to 
varieties  jirttdiiced  umier  nature,  we  are  im"M'iliately 
involved  in  htipi-less  ditliculties  :  for  if  two  hiilierto  r»^ 
jiuled  \arietifs  he  found  in  any  deurree  sterile  tni^i'ther, 
the\-  are  at  once  r.inl.t'd  t'V  most  naturalists  as  >pecies. 
For  instance,  the  Mne  and  red  ]ii'!ipcrnel,  the  primrose 
and  ciiw-lip,  which  are  coii»idered  'i.-  invny  of  our  he^t 
Ixitani-ts  as  \arietie-,  are  s.iid  hy  (iartner  not  to  l»e 
quite  fertile  when  erosse<l,  and  he  conseiiuently  ranks 
them  .'!>  undouhted  sju'i-ies.  if  we  thus  ar^'ue  in  a 
circle,  the  fer'ilitv  o.  .all  varieties  produced  umler 
nature  -.vill  assuredly  lia'/e  to  be  trranted. 

if  we  turn  to  varieties,  produced,  or  supposed  to  have 
Ween  produced,  under  dome-tication,  we  are  still  in- 
volved in  douht.  For  when  it  is  stated,  for  instance, 
tliat  tho  (ierman  Spit/  dojf  unites  more  e;isily  than 
other  <iot;s  with  foxes,  or  that  certain  South  American 
indigenous   domestic    dotrs    do  not  readily  cross  with 


hi 


'^M^^ 


i 


nVMIt     'iSM 


241 


i-iiroj)ear)   di>tr>*,  tlic   o\jtl.iii.i'ii)ii   wiiiih    will    nri  ur   ti) 


priili.illv 


1  \  t'r\'  <>:it',  ;ii,(i  nrnlial'lv  tlic  iruc  n;'",  i~  tliat  tli»'»<> 
(lnj->  liavt' <ic-><  einlt'fl  triiiii  »i'\rr.'il  al'i'ri::iii.ill\  lil-titict 
-jn'fij's.  N(".  »Mtlit'if»<  tlic  jit-rli'.f  I'l'itiiity  <'l "  iiiaiiv 
iii)iiu'-«tic  \aiioti('s,  (iitloriTij;  widciy  t'rom  v.nh  <ilinT 
;ii  Hpiifaratir.',  fur  iii^t.-iiirtr  oi  t!;"  ]ii:r»'oii  nr  of  tin- 
'aliha,'!',  i.-  a  ri-iiiarkaMo  tact;  nmn'  ••-.jit»rially  wln'ii 
Mort'lifi't  how  ui.iiiy  -j.fij.-i  tiifii'  art',  wlm-li,  tlnniL'li 
rcsmililisitf  <'a<  li  ftihcr  inn-;  rlosdy,  art»  iitl»'rly  >.trr:It« 
v^lu'ii  iiit('r«Ti>»-t'(l.  >r\<Tal  « (iii--iilir.'.tii>ii«;,  li(iwi'\fr, 
rtiiilcr  tlio  tcrtility  <»^  dumc-tic  \ari<'ti<'<  1<— >  ri'inaik- 
a:>U'  lliaii  at  tir>t  ajiiM-arx.      It  can,  in  tii(>  lir-t  j.Ia.  i',  Im» 

■  h-arlv  -I'uvii  that  nicrt'  rvtcrnal  i!i--i!nilarity  hctufcu 
\  M.>  «|ii'ci(^>  iluiw  iiiif  ili-tfrmini'  t  heir  urcatrr  or  lf>—i'r 
iif._rri'c  ot  vtcriiity  .Oirii  cro^-rd  ;  aii''  vvc  may  apply  llio 
■imc  ruK'  Id  lioiiic-tif.  Miiiitif^.  In  tlic  x'lnud  placf, 
-irtnc  oniiin'ul  iiai  iirali->t.H  hclitvt^  that  a  Imiir  <<>iir<i'  ot 

■  |lllll(<•^ti(•ati'  II    tfnd>   to  t'liiiiiiiat»'  sterility   in    tiio    suc- 
<'-»ive  p(Mi«*ratii)ns  of  li\  hridn  whirli  wtrt'  at   fii>t  (inly 

-I  .  htly  st»Tilo  ;  and  it  this  he  h»,  wc  Miridy  niiL'ht  not 
t(t    rxpei't    In    find    -tt-rility    hnth    appfarin^^    and    di^- 
apj. raring   under  nearly   the   same   ronditicms   of   lile. 
I.i-tlv,  and  tlii>  .•.ceni^  to  nie  hy  tar  the  n)o-t  irnportam 
i.::-ideration,  new  race-i  of  animals  and  plants  ar  •  pru- 
i'ued  under  duiiiestnation    hy    man's   tnelliodieal    and 
incons('iou:4   power  of  .■»election,  tor  his   own   use  and 
;ileasure:  he  iieitiier  wislies  to  select,  nor  roiiid  .-(dfit . 
'liirlil  ditferenees  in   the  reproductive  sy-tein,  or  otln-r 
'  I'ustitutional    ditVerences    conelated    wiih    tlie    repro- 
ductive system.     He  su|)plies  hi-  several  \arietif- uitli 
the  same  t'oud  ;  treat."  them  in  i^early  tlie  >ame  numncr. 
ami  does  not  wi.-h  t<>  alter  theii   ^''eneral   iiahits  ot"  lite. 
Nature     act-      uniformly     ami      -lowly     durinir     ^"'"-t 
n  riod-i   of  tiino    on    tlie    wlude    or^'anisation.    \n    any 
•:iy    winch    may    he    tor    each    creature's    own    irood  ; 
md    thus  she  may,  either  directly,  or   more   prolialily 
lidirectly,     throufrh    correlation,     modify    the     repro- 
•iuclive    system     ni    tiie     se\eral      descendants      ironi 
juy   one  species.      Seeinir  this  difference   in  the  pro- 
ce.ss  of  selection,  as  airried  on   hy  man   «nd  nature, 

H 


ON    IIIK    OIIKJIN    OK    SPF:(  IKS 


Vkf    in«-cl    iHit    !•<    •iurpri-cfl    al   MUiif   «liffercn<o   in  the 
rf-tilt. 

i  li  ivc  .iM  y«'t  ^imkrn  ;i«  it   t)i»-  \ .iriftii's  of  tlu»  name 

H|.cfii'-  Wire  iiivarviMy  fcrtili'  wlicii  nitrr<TH-.-»'(l.       Mut 

it  ^itiii"  to  nu-  iiniMoi-^ilil*'  to  r»'»i'<t   tin*  rMil»Mue  »i  Ui« 

i>\i-ti'm  o   ot   a   <•<•:•. till   ritiiutitit   of   >tiTility  in   tht*   fVv* 

fnllciu  111;;    f.-i^o*.    \.!ii'li     I     «il!    liri«'t!y    :ili--tr.i<'t.      'I'lie 

t'\  idcriif    i-   at    l«'a-t    a«   ir'""!    '!•<    that    troin    wliirh    we 

licliinc  III  till-  -tcr.lity  of  a  miiltit mio  ot  sju'fii's.      Hie 

»'\  ulrii.f   i<,  aUo,  <itTi\iMi   from   li(i»tili>   •<  itiifsseH,  wlio 

in  all  otlMT  (^-ffs  roiiMiifr  t'rrlilily  ;iii<l  ^t^'rlllty  ax  safe 

tTitirinti*  ot'  sjrt'fitic  ili-tinrtion.      (i.irTnt'r  kr\>\.  <liirintt 

i-r\ir.il    \('ar>-  a  li^arl  kiml  of  iiiai.'»«  witli   y  ■.■>«  set'd", 

au.i   a   tall    sarii'ty    with    n'W   •<«'«'«i>,  utovmu:.'    lu'ar  ••ach 

otlitT   in   Ins  i:,ir<i«'n  ;   iin<l   ailiiontrli   \\iv-i'  |.lant>  have 

f«'t»:i'-.ii.M|    s(.\cs,    tlif'v    in>\  »'r    naturally    cro^si-il.      He 

tl  (Ml    ttTtili-fd    tliirtccn    tiovviTS    of    tlit'    on«»    with    the 

Ih.UiMi  ot   til.'  otht-r;  lint  only  a  sin;.'lc  h«>a(l  jiroiliicetl 

:iiiv  -ffil.  ami  this  ont-  hi-aii  |>ro<liict'i|  only  ti\t>  irrains. 

M.'iiiil.ulatMni  in  tin-  r.i-c  couhi  not  liavt-  Immms  iniiirious, 

a-  t!ii'  j>lint-i  lia\t>  M-jiiratrd  >t\«'s.      Nonn»',  I  holit've, 

Ills  >.u»i><'«!ti|   that    tlii'-e  varij'tif*  of  rnai/«'  arc  lii^tnu't 

-|M'(icN  ;   ami   it    i-*  ini|iortant  to  notu-p  that  tlie  hyhrid 

|'i:int«i  thn^  rai-<''l  wer.'   thfin^'hi's   j'rt'vtly  fertile;   «0 

'li:it  CM'!!   liirtner  <liil   not  vpntiire  to  con-uliM  the  two 

var:i'!if<  a>  sprciticallv   ili-^lun't. 

tiiroii  lie  Un/areiniTut's  rro-.e(l  tliree  varieties  ot 
^'Mird.  whirh  like  'lie  ?!iai/e  ha-  -ejiarated  >e\e><,  aiui 
he  :i— erts  li.it  tli»'ir  imitnal  fertilivitioii  i-  hy  so  nnn'h 
the  l.---;  ea-v  a  their  tlitriTeiu-es  are  irreater.  How  far 
•lie-e  e--i>eniii<'nt-  may  he  trnste.l.  I  know  not  ;  hut  the 
Inrni-  exj^eriineiiti-eil  on,  are  rinkeil  hy  Saj'.iret.  who 
f.iinlv  founds  his  elassitieatic.n  hy  thete-t  ot  infertility, 
it-  \ Mri»»t  les. 

riit>  hd'ouini,'"  <"a-e  is  far  more  reinarkahie,  and 
^eeiMs  at  tir-t  ijiite  inrre'lilije  ;  hut  it  i-  the  result  of 
an  astniii-hiinr  nuintier  of  exjie'-Hiient-  made  durifnf 
n::tn\  \  ears  .m  nine  -|>eeies  of  \  erhasi-utn.  hy  so  t'ood  an 
oil. Tver  and  so  ho-tile  a  witness  as  iiartner  :  namely, 
tiiat   yellow  and  while  varieties  of  the  same  sj)ecie«  of 


'^ 


-Mk 


1   w 

-*5»  ■  «•< 


;-jiiV-,'>-t:; 


.■,.*. .;.'■-»•.., ^r---'>f-; 


:/>■«- r- 


HYltlUDISM 


'Z4i\ 


\>rh»«rum  whon  i!,tprrr(>-*'*<»<l  pnnluco  li-—  ^••«•ll,  tli;iii 
do  «Mtlitr  nili'iired  \ari«'ti»*H  »li«*u  fi-rtiiiM'il  uiih  j-oilfn 
frorii  t)ipir  owii  ((iluiiri'tl  iIohiT'*.  M(ir<'t>vt'r,  In*  a-MTt.-i 
tii.il  »}u'ii  yf'ilow  Hiiii  wliite  v:iri»*li«H  or  <»ii»>  >i|i.Tif4  ;ire 
iri>-«m«<l  will:  Vfll'i*  aiiii  >»!:if»i  vunttn'.i  ^tt  ;»  tiJi'u,r, 
-i>«yit>«,  more  nee'l  i-  prinlur«'<i  \>\  lli»«  «Tov>.e«  l>otwt'«>n 
!li«-  sinul.irly  ((dnurwi  llowers,  Ukui  Ix'twivii  tlio-e 
«Licli  arf  dirfiTtTitlv  « oloircii.  V»'t  til**"*-  v;iri«Mi»'".  of 
\'t'rh;iRciirii  jirfHi'iit  iio  otiit'r  dirieri'iire  l>«'>i.U"<  tl.<»  hut*' 
oUiur  of  tiie  iliivrer  ;  ami  one  variety  i-aii  Mtnietimex  be 
rii-t^i  trorii  t)ie  Ht»eii  ol  the  nther. 

t  ro!ii  (ili-ervatioiis  wLnli  I  hixr  niafi'-  on  certain 
..irietie«  ot  Imllvliofk,  I  am  iiirlmed  to  >.,iv[,(.ct  that 
■ffv  nrceiit  aiiali)i:oii'<  ta',  l^*. 

K    Ireuter,    who've   iitviiraiv    lias    U««'ri    iniifirined   l»y 

.•»ery  Mihse<jtieiil  nhserver,  iiic-i  proved  the  reniarkahie 

fAit.  that  one  variety  ot   the  ((iiiinioii  tohacro   i>i   more 

••r;ile,   when   crossed    wilii   a    widely    di~tinrt   spe^  leM, 

M.;:.    are   the   otlier   varieties.      He  experimetiti>.ed   <m 

>e  inrm-i,  whii  li  are  eommouly  repiile<l  to  he  vanelij-x, 

.    d   wliifli   lie  te-ted   by  the  severe-l  tn.il.  n.imely.  b\ 

.f.iprdrai  crosses,  and  he  found  their  montrrtd  ori-prina 

.-rtei'liy  fertile.      Hut  one  of"  the^e  five  varieties,  when 

-ed   either  ax  father  or  mother,  and  iTo«?>ed  with  th^ 

N  'otiana    trhitinosa,    always    yielded    hybrids    not    ■»') 

t'.sie  a-s   tho»e  whieh    H<'re   produeetl    tmiri    the   four 

I  tr  varieties  when  cross*^!  with  N.  iriutuio^i.      Hence 

!•  roproduetiNO  svtem  of  ihis  one  variety  rnu-it  have 

'  (■(  11  in  some  manner  and  m  nome  deirree  modilied. 

Irom  these  fai'ts  ;  from  the  ifreat  diiHeuity  of  aerer 

i.'iiiiu'  the  infertility  ot  varieties  in  a  state  of  natun'. 

.  'f  a  sujiposed  variety  if  infertile  in  any  decree  would 

.  ■•'.erally    bo   ranked   as   8j)oeies  ;    from    man   seUn'tinj; 

■.!v  external  eharacters  in  the  produitioti  oi  tne  mo>t 

iHtinct   domestir   varieties,   and    from    not   wi^hinj;   or 

•1   '.i'j:  able  to  produce  recondite  and   functiftnal  dirfer- 

piif-es  in   the  reprttdiictive  system  ;  from   the-.e  several 

coiiMiierations  and  facts,  I   do  not  think   tiiat  the  very 

ijeneral  fertility  of  varieties  <an  l>e  proved  to  be  of  uni- 

vf  r-ia!  orcurrenci^,  or  to  form  a  fundamental  distinction 


~;i  -  .    ^m.  a 


■  ivr-.-vV' 


/^.     .,:'.  ','-->  - 


244 


ON   THK   OHKilN    OF   srK(  IKS 


i 


bctwpoii  v.irif'fic-:  ;iti(i  -{)0<-i»'<.  Vhc  ircn^ral  fertility  of 
varieties  dni'<  not  -criii  to  me  <iiniiit'nt  to  overthrow 
tlic  \ic\v  uliirli  1  liii.e  taki'ri  uitii  n'-|toct  to  t)ie  very 
pr'ni'r.-il.  h':\  no'  in\■.•u•i:l^'<•,  wtcrilify  of  iirst  cro-^op  aud 
ot  iiyltri(i>.  n.iiMi'!'.-.  tli.it  it  i>  not  i  -j>"cial  emiowment. 
Imt  K  iiir'il."i'.il  on  -low  Iv  nc-jiiircl  iiioilil'.c:itioi:<.  nutre 
i'-j)Of';il!v  i'l  '.•it'  rt'jirotliictive  sy-teins  of  the  fornriB 
which  art"  eio-- cl. 

Ihi'irids  fill'!  M<!)i'irr's  rninpured.  rn'/ri.fji'lrtif/i/  of  Ihnr 
/i-WiVi/f/.-- I  idi'i'.MulfMitly  of  'he  ■|';p.t;nn  of  ftMi'lity, 
the  otf-pri'L'  of  ^irt'cie-  when  crc-J-fi  rnni  of  varieties 
wlieri  cro'-^'l  !ii:i\  ite  fotiinire'l  in  <overal  n'Ji.'r  r<'-jM>cts. 
(i  irtntT.  «ho>-e  -troiitf  wi-ii  wa-i  to  draw  a  niarkc  I  line 
of  (ii-^tinctinn  Kotween  »jiecle- and  \ar:etie-,  conhi  find 
verv  ftnv  atid,  ;)•<  i*  seems  to  me.  .iuite  iiniriiportaiit 
diJierences  hetwt'en  the  -o-calh-i  hytirid  nlf^prin!;  of 
8](ecies.  and  tlic  -o-calh-d  nu'iiuTcl  orfsprm^- of  variftieu 
And,  on  ti.i'  other  liand.  th(>y  airree  most  closely  in 
\ery  many  itniioi-t.mt  resjiocts. 

Ishall  here  diM-iiss  this  suhiect  'vith  extreme  hrevity. 
Hie  mo>t  nn]>ortant  distinction  is,  that  in  the  rtfHt 
^'cneratioii  moti^i-nds  are  more  variahle  than  hyhrids  ; 
hut  (JiTlner  admits  that  fiyhrids  from  -ipecies  '.vhioh 
have  |i-n._r  heeii  i-iiltivated  are  often  variahle  in  the  first 
generation  :  and  1  have  myself  seen  strikidL'  in^-tancofe 
of  t]ii«  tact  (lartner  fiirtlier  admits  that  hyiirids  be- 
tween \er\  (losfly  allied  species  are  more  variahle 
thin  tho-i'  from  v'erv  di-^ti net  species;  and  thi-  -liow? 
that  the  ditfereni-e  m  the  di-irree  of  variahiiity  irrailnate^ 
avav.  \\  hen  nionu:rcls  and  the  more  fertile  liyt>rid>< 
are  j>ron.i:raled  for  several  trener:;'i<.ns  a!i  extrenie 
anioiii.t 'of  variahiiity  in  their  o'-prMiir  is  notorious; 
hut  some  f»-w  ca-^s  hoth  of  hyitr.d;-*  uid  moiiLTcls  hinjr 
retainiiitr  nniformitv  of  chara  .ter  could  be  j-iven.  I  he 
variahiiity,  houe\er.  in  the  successive  jrcnt^ratiouH  of 
mniiirrids  i>,  iierhaps.  L'reater  than  in  h;''ridn. 

This  L''reat('r  variatulitv  of  monirreis  ttian  of  hybrids 
doi's  not  socm  to  me  at  all  snrprisiiiir.  For  the  parent* 
of  inontfrels  are  varieties,  and  mostly  domestic  varieties 


jWr 


m^^im^^m^^i^^Bsmm^^sm^mwmi^mE'mi'-mtt.Tm 


HYimiDISM 


245 


fvory  few  exi)erimeiits   haviiitr   h»MMi   trio<l    on   imtural 
vari<;ies),  aii<l  tliis  iini>lies  in  nuxx  ca>es  that  tliore  has 
■jvt'u  rcieul  vf.rial.ility  :  aii<l  thrrefore  we  ini-ht  t«xi)ect 
•li.it  >uch  varKil.ililv  wouUl  (tftcii  .oiitiiiue  and  l'«'Mij.er- 
ad'lt'd  to  that  arisiiiir   from   tlie  nier.-  art  ot   rn.^in:,'. 
Iho   ^litrlit   (Icirrt'f   of  variahilily   in    liyliriils  from   the 
hr^t  croos  or  in  the   lir>t  ^rt'in'ration.  m  contract  with 
heir  extreme  varialjilit\  in  the  .-.ufcee<lintr  ueiieration>, 
IS  a  ttirioiis  fact  and  deserves  attention.      I  or  it  hearv 
,>n  antl  corrohorate.-*   tlie  view   vkhirh   I   liave  taken  on 
'in-  rauKP  of  ordinary  variability  ;  namely,  th.it  it  is  due 
to   the  reproductive' sy>tein    heintr  eminently  -ensitive 
u)   a;i\    chanire   in    the   .onditions   of  life,    t^eintr   thuH 
itteii   rendered  either   impotent  or  at    least   inrajtahle 
of  ax  proper  famtion  of  produrinir  otf-prinir  identical 
With  tlie  parent-form.      Now  hybrids  in  the  tin-t  treneni- 
lioii  are  deseendtd   from  >pei  ies  (excludinjj  tho-e  lont' 
,ult;\ate<l)    which    haxe    not    had    their    reproductive 
-v-teins  i     an\  wav  atfectcd,  and  they  ar.       .t  variable  ; 
i.ut  hybrids  tbem>elve-  iiave  their  reproductive  syst»-ms 
-.riou-Iy  affected,  and    tiieir    descendants    are    hiijl 
\;irialile. 

I'.ut  to  return  to  our  comparison  of  moiiL'-rels  and 
•lybrids:  (i.irtncr  states  that  motiirrels  are  more  liable 
♦  I'l.in  hvlirids  to  revert  to  either  parent-form  ;  but  this, 
I  it  be  true,  is  certainly  only  a  ditiVrence  in  detrree. 
•tn.T  further  in>i-.t.> '  that' when  any  tu.'  species. 
;  iK.Ui;  i  most  closely  allied  to  each  otiier.  arc  cros-^ed 
vvi  1.  .1  third  spcies,' the  hybrids  are  wi.iely  different 
•i..t.i  each  »»thcr;  whereas  if  two  very  distinct  varieties 
■  ,i  one  s|KK'ies  are  crossed  with  anotlier  species,  the 
(,ybrids  do  not  dirfer  nnich.  liut  this  conclusion,  a*« 
r-ir  liA  I  can  make  out,  is  founded  on  a  sin^rle  e\i)en- 
II. cut  ;  ind  >eem8  directly  opjtosed  to  the  results  of 
rr^enil  experiments  maiie  by  K.'lreuter. 

11, .-e  alone  are  the  unimportant  ditference*,  which 
tJ.irtiicr    is    able   to    point    mit,    i'etwt'en    hybrid    and 

rJn»iiurt5i    piriiilS,        XfH     i»*C    Ui::tr:     iirttt-t^ - 

in  iiioiijirels  and  in  hybrids  to  their  respective  parenU, 
more  eH.,ec-ially  ui  hybrids  produced  from  nearly  related 


^^^^^^5.. 


^^^m^ 


246 


ON  Uli;    (U{I(;iN   OF   SI'E(  IKS 


'V  u 


ili 


i 


snccio-;,  f<ll()w  rKijor'lmy  to  (iartupr  tl'«*  ^rlme  laTP. 
\\'lion  two  -iixMii's  nrf  cro^sod.  oiu'  li.is  ^ornotimet 
a  prt')i()tiMit  ji(iw«»r  of  imjirf'ssinir  its  l'kciu'>>-'  on  'hi^ 
hviniil  ;  .iii'i  'io  f  lu'l^nc  it  to  he  wiili  \ariefie^  "i 
plaiit-i.  V\'itli  anirn.'iU  oiio  \:ir  c' y  ctTtaiDlv  ofVn  ha- 
tlii-  |ire5K»ttMit  j>owtr  mer  HiMi'lier  \.iri<'tv.  Uvhr^'l 
{ilaiT'^  |>r<'ilijff>il  troni  a  rociprocal  .•r(i<;s,  e'lHTally  re- 
soinliU'  JTirh  other  clu-clv  ;  arjii  so  ;t  i-^  with  moiitrrols 
from  a  ri'i-ijirM/al  crixs.  Motli  Jiv'iriiiw  ami  nuHiLTt'ls 
r^'iii  he  rodiHCfi  to  jmiIht  {mitp  |>arf;it  fnrrn,  hv  rcjicatfd 
cro->»'-!  in  s\l'•^r>s^ive  trt'urratioiis  witli  rithrr  pnrtTit. 

I  li»"i»'  sc  IT  il  remarks  are  ajipareullv  api'liiahle  to 
aiiiiii  il»  ;  t)i;t  ttie  sul>jpet  is  liere  excessiveiv  ronnili- 
cato'l.  partl\- owMii^  to  tlie  exixtence  f)f  ficcotidarv  "seiiia] 
oliarai'ttTs  ;  Imt  iimre  especiallv  owiiijr  to  prepot^noT 
ill  traii-niittiiiL'"  likeness  ruiinirijr  more  ftroiigly  in  onf» 
sex  tiiaii  III  tiie  oMier,  liotli  wlieii  one  species  is  rroHsod 
with  mother,  and  when  one  variety  is  missed  with 
another  variety  For  instiiieo,  I  th'nk  those  author? 
are  ritrlit.  '*h<i  r.iaintain  that  the  ass  )ias  a  prepotent 
power  over  the  horse,  so  that  tioth  tlie  mule  and  tiie 
iiiiiny  more  reseniMe  the  ts'j  than  the  }ior>^e  ;  hut  that 
the  prepoteiu  •  run->  more  stroni:lv  in  the  ma!e-a.ss  than 
in  the  female,  so  t}iat  the  mule,  which  is  the  oifspriujf 
of  the  male-ass  and  mare,  is  more  like  an  ass,  than  is 
the  hiiinv,  which  is  the  otl^prinir  of  the  feniale-as«  and 
Ktallion. 

Much  stress  has  l>een  laid  hv  some  authors  on  the 
Bup!)os«-d  fact,  that  monirrel  an:nials  almie  are  !>orn 
cl(i-''ly  like  one  of  thoir  parents  ;  hut  it  <a:i  he  sliown 
that  tliis  does  sometimes  occur  vvith  livhrids  ;  yet  I 
(rrant  niucli  les.s  freqiiently  with  hylirids  tlian  with 
motiirrels.  l/ooking:  to  the  cases  which  I  have  colle<'ted 
of  cross-lired  animals  clo-eiv  resemhliiiir  one  |>arent, 
the  re-^ernhlanctv  seetn  cliiefiy  confined  to  cliaractera 
almost  monstrous  in  their  nature,  and  which  Lav© 
fiudti'Mily  appeared  -such  as  aliiinisim,  melanism.  d#- 
noie.u  V  or  u<ii  oi  iiorns,  ot  iildiuoUai  ruit;ers  .tuu  Iajc*  , 
ami  do  not  relate  to  cliaracters  which  have  heen  sjowlr 
acquired  by  selection.   (  on^djueutly,  sudden  reversioui 


HYBRIDISM 


247 


il 


U»  the  i»erfort  chanu-ler  of  pitiuT  parent  would  Ik,  more 
hkelvtoofcurwithmoi.irreU.winrh  ar.«  .l.'M-etHle.l  f:..m 
varieties  ..tleu  .-u.i.l.-nlv  |.rn,i.ir»«.i   an.l  ..-MU-inoi  ^inms 
m   ,-hararter,  tha>.  wtl.   LyLrwis    whi.h   arr  .i-Myn.UMl 
Torn   M.i'.-i.'s    .U.wlvainl    nalunilh   i-rodio  nl.      On     ne 
.hole   I    t-nf.r.-iv   aur.'o   wuh    Dr    I'm^p.-r    Lii.a.>,  «!m. 
,:t.^r  arranuinir  an  oiiorm..u-  l.."ly  ot  i.i.-Ln  with  r.-^i-ort 
U»  animaU,  ronH-s  t..  'i.e  n.n.lu^n.n.  ll.at  tl.o   law,  of 
...,wnhlano.  of  tl..,  rlul.l   to   .U   par.-nts  are  t  ,.•  s.n..-. 
wlu-Uier    thf   two    ,..ir.-nt>  .li.f.T    nuul.    or  little    tron. 
,vi.-li   oth.^r.  nauH'lv  in  ll:.^  •mion   of  .u.livi.lua.s  nt   ti.e 
,.ime  varu'ty,   or  of  .liih-n-ni    uirieUes,  or   oi   .l,>lin.t 

■ipei-ies.  .  .       ,.  ,  •'■,,.;,, 

UvinL-  a>i.le  ll.e  .,ne^tioM  of  fertility  a-ul  .  .TMitv  in 
.11  other  re.-neob,  there  >ee.n-  to  he  a  u.-.o-ral  a...!  .•■.-.• 
Htmilaritv  in  ll>«  otrsprin.-  of  .to,..-.!  -i-r.-.e,.  .uul  -t 
cro^Mxi  varieties.  If  we  look  at  sj-eeies  as  h.ivin-  ..-en 
.penally  rreate.l.  an.l  al  var.et.es  a.  hav.njr  he.-, 
urodured  hv  ^>con.larv  iaws,thi>  -iinilaniy  «oiihl  he  an 
a^toni^hin-'faet.  liut  il  hanooni.-es  perle.lly  wun  the 
view  that  t  h.-re  is  uo  esseuliai  .iisUncUon  between  speeies 

ami  varieties. 

>./mm./rv  of  ('hapt^r.-Vu..  .rosses  lK.twe.-n  forms 
.uth-ienllv  diVtin.-t  to  he  ranked  !i.s  .pecies;uid  their 
hvhnds,  are  very  ^'enerally,  hut  not  univers.iilv,  ^tenle 
Ihe  sterility  is  of  all  dej-rees,  and  is  otten  s<.  s.i-lit  thai 
'ie  two  most  .arelul  experi.nent;ili>ts  who  have  ev.T 
!i\ed.  have  .••»Tne  to  diameiri.:ally  opposite  oonrlusions 
m  rankiutf  forms  hv  this  test.  Tlie  .tenl.ty  is  nwiatelv 
vari.ihle  m  individ'uals  of  the  same  specu^*,  and  h 
.■miiientlv  «u>.M-ptilde  of  favourahle  and    untavoiirao  e 

oM.iitions.      llie  de-ree  of  sterility  doe>   not  str.-tly 
i.uh.w  systematic  athnity,   hut  is  governed   hv  sev.-ral 

•.nnu.  and  con.ph-x   laws.      It  U  generally  ditferent, 
«u<l  ^ometime9  widelv  different,   in    reeij.ro.a!   rnw>es 

■ervveen   the  -.ime  two  specie.^.      It  is  nut  ulways  eyial 

.      1    :..    ..  i^y^t   rro^-  and   in   the  hvhrid  itrtxlu.  I'fl 

trotn  tlii>  iTo«-.. 

In  the  ~ame  manner  a«  in  ijraitnitf  trees,  the  capacity 


^\^ 


248 


OS    rilK   OUKJIN   OF  SPE(  IKS 


;l 


Is'  i 


iv- 


ii 


-^ 


111. 

13  f 


--  g- 


; :  ^J-. 

p- 

iS 

i 

oMiiie  sjX'cu's  f»r  variety  to  take  on  .inothor,  is  iru  idpiital 
on  jrtMicrally  iiiikii'iwii  (litftTciices  in  their  vt'L-^etative 
HV^tfrii-,  M)  iti  (•r()--iii::,  the  {.'reaternr  h'ss  tai'ility  of  one 
s|>ecii>>.  to  unite  «  itii  aiiiitli.-r,  i^  iriciileiital  on  iinkiit)wu 
di(f('rein-e>i  in  tlieir  reprudm-tive  .-Nvteins.  I'here  is  no 
tiHire  re.isdii  to  tliiiik  tliiit  ~[iecie-.  h.ivo  heen  siiecialh' 
endoue'l  with  \arii>'i>  ile_Mi'c,  of  .-tcrility  to  jireveut 
thern  cnt--iii:r  ami  lih-mliiiLr  in  nature,  than  to  think 
tli.it  trees  h.ne  heen  specially  emlowefl  uitii  various  and 
H<iiiie«hat  atialoL'-ous  de^rrees  of  ditriiiilty  in  beintj 
^rraitfd  lo-ether  iii  order  Ut  prevent  them  beeoniini.' 
inarched  in  our  foie-is. 

'I  he  -tcrility  of  iir-t  ero>>-es  hetvveen  [«ure  species, 
which  lia\i'  their  re|ii(»diicti\e  sv>tein-  pfffect,  seems 
to  dfj.ciid  ou  scver.il  circum-tance- ;  in  some  cases 
lai-L'-ely  on  the  early  deatli  of  tlie  enihryo.  'I'hc  -terility 
of  l;vl)riils.  which  ha\e  their  reproductive  system's 
impt  ifect,  and  whi.h  ha\e  h.ni  tliis  system  and  their 
uliulc  or;;-a!ii>atit.n  disturbed  hy  hein^;  eompoundeti  of 
twi>di>tiiict  >pecie«.,  seems  cio>eIy  allied  to  th.t  sterility 
which  so  freijuently  affects  pure  sjK'cie-:,  when  their 
natural  eoniiitious  of  li;i'  ha\e  heen  di-turhcd.  This 
vic.v  i-;  '^uj. ported  hy  a  paralleli-m  of  another  kinrl  ; — 
nauiely,  'hat  the  cro-isirijj  of  foriiK  only  sli^/litly  ditlerent 
i-  ta\  oiirahle  tf)  the  viiTour  r.nd  fertility  of  their  offsj>ring  ; 
and  that  sliirht  eliaiiires  in  tin;  cotiditioiis  of  life  are 
apparently  favonra'de  to  tiie  vit'onr  and  fertility  o."  all 
orL^uiic  heiiiirs.  It  is  not  siir{>ri>injr  that  th?  decree  of 
ditliculty  in  unilinar  two  specie-^,  and  the  <lejfree  of 
sterility  of  their  hyhrid  -  otrs])rinff  should  jjeiierall 
CO  re-i|MHid,  thn  i;r|i  (l,j,>  to  di-tnu^t  causes;  for  b 
dcpciid  (HI  the  amount  of  dilferenco  of  some  kiud 
i>-lweeii  the  -pecles  which  are  cro-.-ed.  Nor  is  it 
surprisinT  that  the  facility  of  effectinir  a  first  cross, 
the  fertility  of  the  hJ.rids  produced  from  it,  and  the 
•  apacity  of  hein<»-  trratted  tojrether— thouirh  this  Utter 
CHjiacity  evidently  depends  on  widely  different  circiim- 
si.uices  -^should  all  run,  to  a  certain  extent,  parallel 
with  the  systematic  atKnity  of  the  forms  which  are 
subjected     to     experiment  ;     for    systematic     affinit? 


oth 


IIVBIUDISM 


249 


„ttempti*  to  expn-vs  all  kiiid^  of  resemMance  »«tween 

.-xll  species.  . 

Kir^t  .•ro-J^*'?  heUi-on  tormn  Known  to  he  varieties,  or 

••utRnentlv  filik(>  to  i.e  coii>'iK're<l  as  xarie^  lo-.  and  their 

m.iitrrel  otNprinc,  are  verv   eonerallv.   l.ut   not  quite 

;nvi-r-;.;lv.  tertile.      Nor    i8    this   .i,>;.r!>     trnioral    and 

i.rrfect  frtilitv  surprisini;,   '^hi-n    we    remfinher    huw 

1.  il.le  we  ar«  to'ar-ue  in  a  oinle  with  rospe.t  to  varieties 

-,  -i  etate  of  nature  ;  ami  when  we  renicnil.er  tliat  the 

reater  numher  of  vari.'ties  haxe  hci-n  produ.e.i  under 
'on.estication  hv  the  selec  n  of  mere  external  ditfer- 
,  Mies  and  ii.  t  oVdirterenc  in  the  reproductive  system. 
m  ail"  other  respe»-ts,  excludinjr  fertility,  therein  a  doH« 
■  M-neral  reseml)lanr.'  hetueeu  hyhrids  lind  moni^rels. 
K  iiallv  then,  the  fa.ls  hriedv  tfiven  in  this  chapter  do 
rn.  ^ei-tn  lo  me  opposed  to,  hut  evu  rather  to  ^upport 
t!.^  Mew,  that  there  i»  no  <-undamenUl  d^stii.a  on 
•,v  -weeu  species  and  var'.fties. 


I'M 


fM  i 


m>mk 


(   HAl'l  KR    IX 


OV    r»!K   IWritKFK"  TION   UK    THK.  GIIOI,a<iI     *l     RKt'ORD 


'  n  thf>  »i««''i(  (•  ■.(  !iit/'rni'>(ii»t«'  vnriptiis  itt  th*"  [>rf'<Tit  ilay— On  th6 
in»Hii<-  ■'•  eitiin  I  uiuriiKiiKit*  varirtioi  ;  in  their  tiuii.l'tr  tni 
Ihi'  viiAt  la;**"  of  tiiiic.  a»  i!ift'rri<l  fr  iii  tin-  rit«  f  .ir;..";ti  n 
•ii<l  of  'icuiihitlon  -'In  t!ir  ["'"'■'i''*'  ''  '  "r  jial  i'<.nt<  1  /i  <0 
C!!le<Uoii8  (»ii  thn  liitoriMlteii' e  ■{  Kivpl.^ifal  (■•r'natlnn - 
On  tlif  iti'ti',.  o  f  lilt'-:  mt'Iki'.''  \ariitiei  in  any  >n- f  rv.n:;  n  - 
On  tfio  »ii  i  kii  kpi-fariii  ••  of  cr  ■'.;■*  1  »\  •■■i>^  -  • 't}  ihdi  tnlleo 
ni»(»-i4ran>i-  in  I'.e  lowest  known  fo-,sili(erout  ^tr»U. 


Ivthi'  s'\t  ii  rliaptor  I  eiiumf  rated  thi' cliiff  ohiectionf" 
*»)iirli  III!,  ht  1)0  jti'^tlv  ure»'<i  .liriiusi  il>e  views  niaitJ- 
taiix'd  ill  lliw  vdhi'iie.  Most  of"  tlit-m  have  now  Uccn 
iliscii>--0(i.  <  >np,  iianielv  t!:t«  distiin'tiu'Sfi  of  s|»«Mit"ic 
tornis.  and  tliiMr  not  ln'iiu?  Iilpiid«>d  t<»Lr<'ther  '>y  in- 
niiniHr.ildi'  transitional  links,  is  a  v»»ry  olivious  diriinillv. 
!  a^-'.'!ifd  ri'asuiis  why  -.iicli  links  do  not  ronjiiionlv 
oi  1  ur  it  tln>  present  day,  under  tiie  circurnsUtncfts 
.1' jiarently  most  tavoiirahio  for  tiieir  [ireserit-e,  namely 
on  an  •'xteM>-ivi>  and  oontinuous  are^i  with  irraiiiiaied 
nhysi.a!  conditions.  I  endeavoured  to  nhow,  that  the 
life  ot"  caeli  species  depends  in  a  more  important  manner 
ftn  the  pre^eisre  of  other  alre:uiv  derine<i  ortrnnic  torn's, 
than  on  I'limate  ;  and,  tlierefore,  tli.it  the  reallv 
iro\erniMr  condit'ons  of  life  do  not  trraduate  away  <iiiit4< 
in-ensihlv  like  heat  or  moisture.  1  endeavoured,  .ilso, 
to  siioi*  that  inti^rniediate  \ar;etieB,  frt>!n  exislinir  m 
!es>er  nnn;!iers  than  tlie  forms  wh'cli  the)  I'onnei'l,  vmU 
frenerally  he  Ixjaten  out  and  evterminated  during  the 


IM1»ERFE(TI()N()K  GEOU)iiK  AL  RECORD  251 

course  of  turtlier  modification  and  iinprovemont.      I'be 
main  cau^c,  ho*.>.er,  of  innumerahle  uitiTim-diaUs  links 
n,.t     now     .M-carnniT    evervwlu're    tlirontil,niit    n-itura 
d.*poiid^nti  til.'  vervpnM-osHof.jitural  sclei-.!oi.,throui'h 
whirh  new  %anetie,«.  iMuitiiiually  uk*^  the  places  ot  and 
Pxtermmate  their  parent  turms.     Hut  lu^t  m  proportion 
a.,    thif»    process   ot"    extermination     has    a.ted   on    an 
f^nornious  <r  ile.  so  must  the  nuinher  of    intermediate 
varieties    Hh.cl.  have  formerly  existed    on  the  earth, 
Ke    trulv    enormous.      Whv   then    is    not    every    ffeo- 
lo.'u-.il  tnrmation  and  every  stratum  hill  of  ^ueh  int^'r- 
mrdiate  l.nks  ?     (ieolojry  assuredlv  does  not  rovea    any 
^url.  hnelvtrraduated  orcanic  rhain  ;  an.i  tins   jrt?rhaps, 
w  the  mo-it  obvious  and  ^rave-sl  ohjecti<.n  which  .an  V* 
.;r..ed  a;:ain<t  mv   theory.       Hie  explanation   he-,  as 
»„.lievo,  in  the  extreme  imi)erfection  ot  the  Keolojfical 

'^Vn"  iie  first  pl.-^ce  it  should   always  be  tK>nie    n  mind 
wh;»t  sort  of  intermeiiiate  forms  must,  on  my  thecir), 
base  formerly  existed.      I  have  found  it  d:fT:cult.  when 
lo..kine  at  any  two  species,  to  avoid  picturintr  to  myself 
forms  ,/,r^-fVintermediate  l>etween  them.      But  this  is 
a  wboUv  false  view  ;  we  should  always  look  for  form- 
intermediate  between  each   species  and  a  common  but 
ui. known  prourenitor  ;  and  the  proirniutor  wilU-eneraUy 
have  differed   in  some  rosi)ect.s   from  all   it.s  m..d!tieri 
'le^rendmt.',.     To  trive  a  simple  illustration  :  the  tanUiil 
iiMi  pouter  pi>?eonshave  both  de««:ended  from  the  roi-k- 
pieeon  ;    if  we  iH)sKessed   all  the  u  termediate  Tarietie. 
wlM.b  Irivo  ever  existed,  we  should  have  an  extremely 
close  heries  between  botli  and  the  ro<-k-piiroon  ;  but  w». 
^houlH  have  no  varieti.M  directly  intermediate  Wtween 
the  fautail   and   pouter  ;  none,  for  instance,  cornbinmir 
*   tail  somewhat   expande<i  with   a  crop   somewhat  en- 
l;ir-.'d.  the  characteristic  features  of  these  two  t.reesi*^ 
Ih.'«;e  two    breeds,    moreover,    have    become  so   murh 
moditied,    that   if  we   had     no    historical     or    indirect 


.1  J »    I.-. 


VO    ri^^^n 


e\  i<it'nce  rc..';iriiiini  Uieir  ruig^n,  "•>. 

possible  to  have  de^'rinined  from  a  mere  comp 

their  .tructure  with  that  of  the  ruuk-pirfeou,  wheUier 


nri«><i 


II  of 


262 


ON   THK   OKKilN   OF   SI'K(  IKS 


m\ 


s? 


they    had  ilescended    Irom    t)iis   aperies  or  frtini  rtome 
other  ;illii'(l  sjiccio-i,  such  as  (  .  oeiias. 

.So  with  natural  s|ip(  ics,  if  we  htok  tu  turtris  very 
diHtiiiit,  for  iiistatice  to  tliW  h<ir-«»  and  t.ijiir.  we  have 
no  reaxin  to  «-up|in-f  that  links  I'vcr  ('xi>t('(l  directly 
iiiti-rnu'diate  ln't««.'tMi  thfin,  hut  hi-tv*(>»'ii  each  ami  an 
Liikiiuvvn  romnicn  |>arcnt.  Tho  coninion  parent  \»ill 
have  lia<l  in  its  wliole  oriranisation  hmk  h  ceneral  rosem- 
hiiincf   to   the   tajiir  and    to   th»'   hoi-c  ;    hut    in   >>orne 

IMnnt>  (>i  struitiire  may  ha\»"  diihrtMl  con-^idfrahly  from 
lolh,  even  perhajis  more  than  they  differ  from  eaeh 
other.  iieiice  in  all  Mjih  rases,  we  should  he  uiialile 
to  recognise  the  parent -Ibrm  of  any  two  or  more 
t'pecie-i,  e\en  if  we  closely  compare*!  the  ^tru^•tli^e  of 
the  parent  with  that  of  its  nioditie<l  descendants,  unle,ss 
at  the  same  time  we  had  a  nearly  perfect  chain  of  the 
intermediate  links. 

If  is  just  po<sihlo  hy  my  theory,  that  one  of  two 
llviiiff  forms  m::,'ht  have  <lescended  from  the  other;  for 
instance,  a  horse  from  a  tapir;  and  in  this  ca>e(/*r'C< 
interme<liate  links  will  ha\e  existed  hetvs oen  them, 
hut  pucli  a  case  would  imply  that  one  form  hail  re- 
tuained  for  a  very  Ion:;  period  unaltered,  whilst  its 
descend. int>  had  undergone  a  vast  amount  of  change  ; 
and  the  principle  of  competition  hetween  oiiranism  and 
orL'anisni.lu't  ween  child  and  parent,  will  render  this  a  very 
rare  e\ent ;  for  in  all  cases  ihe  new  and  improved  forms 
of  life  tend  to  supplant  the  old  and  unimprove«l  forum. 

IJy  the  theorv  of  natural  selection  all  iivinif  species 
have  heen  connected  with  the  parent-specu-s  of  each 
l^enus,  hy  ditferences  not  trreater  than  wo  see  hetween 
the  varieties  of  the  same  species  at  tho  present  day  ; 
and  the.se  parent-species,  now  jrenerally  extinct,  ha^  i 
in  their  turn  In'en  similarly  connected  with  more 
ancient  species  ;  and  t,o  on  hackwards,  always  con- 
verj{in^  to  the  common  ancestor  of  each  preat  class. 
So  that  the  numher  of  intermediate  and  transitional 
links,  i>etween  all  iiviutf  and  e.xt  '  t  species,  must  have 
been  iuconceivahly  g'reat  But  assuredly,  if  tins  theory 
be  true,  such  have  lived  upon  thiH  earth. 


IMPKRFECmON  OF  (iEOlXXilCAL  RECORU  263 

on    tht  i>ir"<''  "'"   Timr.  -  lutlepoiKl'Mitly   of   our    not 
finrliiiir  fossil  remains  of  ku.  I.  iiUiiritrly  luimornus  con- 
n.Ttii.ff  lif)L-,  it  inav   he  ol.iorto.l.  th.it  timr   will   nut 
h,-,vn  snffi.T.l  furs..  ^'^fAt  rin  amount  nt  ..r-:ii!K  .h.-uitre, 
■^\]   .•h:u,u^o<    l:;ivin-   U-en  ..ifrrtcl  vorv  «ln<x  ly  tlir..M,rh 
■  •ituril  <el<N'tiun.      It  is  l.vnily  i-o.-.'-lo  lor  me  »-y-n  to 
ro.all   ro  the   r.'iL'r.  who  may  not  l.e  a  prartn  al   iroo- 
io-ist   tl.p  ta.t.  lea.iinir  the  mmd  feel.ly  to  .-..mprMuMid 
,!,;    lai.-o    ot    time.       Ht>    vrho    ran    r.-a-l    >ir    l  I,  irlej, 
I  v.-ir^  --raJid  work  <»ii  th.'  I'nvrifUrs  oj   i^>-ot...ni,  wlii-li 
tl  M  future  ].i-t..rian  will  rocoirni^.-  as  havmir  pro.luc'd 
a  rrvnlutioii  in  natural  M-ienre.  vet  «loos  not  a-lmit  how 
-,...mnrelMMi-iv,.|v  vast  h.v.H'  h.-en   the   ,.a.t j.-r.-vls  of 
Mine,   niav    at   nn.p   cIom-   this    volume.       Not    tuat   it 
,•,, Hires  to  .=tu.h'  t1...    I'rinnjdrs  of  ^VoA.vv.  '«r  to    re;%i 
M.<"ial    treatisrs    hv    different    ohservers    ..n    M>i.araTe 
formations,  atul  to  mark  how  each  author  atfrnp's  to 
L- X.-  an  iua.lequate  idea  of  the  .luration   of  earh  Jorma- 
.  ..,,   or  oven   each   stratum.      A    man    mu>t  for   yean 
..tamMie  for  himself  trreat  piles  of  .ui...nmi.osed  strata, 
and  watrh   the  s.-a  at  work   trrin'imjr  'h>«n  old   rocks 
and    makintr    fre-h    pediment,  hefore    hr  .-an    hope  to 
rn-nprehond  anythint?  of  the  lapse  of  time,  the  monu- 
iii»'n»<  of  vihivh  we  see  around  us. 

It  IS  lmxmI  to  wander  aloiitr  lines  of  ^ea-coast,  when 
tnrmed  of  moderatelv  hard  n.rks,  and  mark  the  pro.-ess 
..f  degradation.  1  he  tides  in  most  case's  rea.h  the 
,  liT.  onlv  for  a  short  time  twiee  a  day,  nnd  the  wavea 
.•at  int..  tlH-m  onlv  when  they  are  .-harired  with  «ai..i  -r 
nei.hle^;  for  there  is  c().)d  evidence  that  pure  water 
.  ui  effpct  little  or  nothinsj  in  wearinff  awav  r.ick.  At 
la^»  the  ha-^i>  .>f  the  rlitf  is  undermined,  lui-.-  tr.Oirments 
Jail  down,  iv.d  the.e  remainii'L-  H.xed,  ha^e  lo  he  worn 
auHv,  atom  hv  atom,  until  redu.'ed  m  si/.e  tuey  i:an  l« 
r.  It.Mi  ahout  i.v  tlie  waves,  an<l  then  are  more  <;..Mkly 
irruund  into  pehble.^  sand,  or  mud.  lint  Ih.w  ot>.«>«i  ^o 
we  .P<.  al..nir  the   hases    of    retrcatintr  clttfs   rounded 

,  ,   .  11      .1    ■     t    1..      .1     t  I,  ^.1      i.ir     r>\'krir)o     Tin  )(t  t  iri  tt  II 11 . 

tnni   ti 


u.«'ho-.v  little  the\     re  abraded  and  how  seldom 

they  are  rolled  about !     .Moreover,  if  we  follow  for  i 


sh..>TUUi: 


264 


ON   THK   OIlKilN   OF   8PE(  lES 


\i 


U'w  m\]o»  any  lino  of  rot  ky  clitF,  wliicli  is  undoreoinn 
«lfirr.i.l;iti()ii.  wt-  fi,    I  tli;it  ii  iHonly  li«'re;iti.l  tlitTo,  alorijf 
a  hhnrt    h-imtJi   ..r  roijii.l  a  firnrnoritorv.  th.it  tlif»  rlirfH 
are  at   tJu*  pn-^jMit  tum'  •.utfcniiif.      'Ili«' aj>ii«'ar;uicp  ol 
th((   ,surf.i(t»   iiiiil    the   \r{r»'t.4tiiiii   h1io\«'    tliul   eUowliere 
ve.ir«,  ii.ivd  «'l.i|isO(l  siiiro  tJi«  "iitrr^  v».im1um|  tlicir  base. 
Hf  i«lio  tii(»t  •  l<>-.«»ly  studies*  thf  action  of  the  nea  on 
Our  sliores.  will,    I    i.clicv««,   !.««  tuont  (icepis    impresHftd 
with   the  Rlt^wni's.-   v»iili   which    nx'ky  co.i^tM   ;irp   worn 
away.       I  he  oh^iTvatioiiH  «)n  thin  head  h\   llnch  Miller, 
nutl   hy   that  excellent  ohserver   Mr.    >r'  itli   of  .foniaii 
Mill,   are   nm-t   ini|.re'.>*ive.      With    th*  iniiui   tlius   im- 
pressed,   let   any   one   evitnine   l)eils   of  conirloiiierate 
man\   thoiisaiid  /eet   in   thic  kne>s,  which,  thouirh  prol>- 
ahly    funned     at     a    <|iiicher    rate    than     nianv    other 
deposits,  yet,  Iroin  hciiiir  formed   of  worn  and  rounded 
pehhles,  each  td   wiiich   lK»^rs   the  titaiiip  oi    time,  are 
ffood   to  kIiow   how   Miowly  the  ina.s>  lia.s  l.een  accumu- 
lated.     In   t)ie  (  ordillora   1   estimated   otu-  pile  of  con- 
jrlomerate  at  ten   thousand  feel  in  thickne>Js.      I^et  the 
ohi>erver  reiiiemher   l.yelJH  profound    remark   lliat  the 
thickness  and  extent  of  Kedimeiitary  formations  are  the 
re.sult  and  me.-mure  of  tlie  dejjradation  which  the  ear! ' 
crusl  ha?,  elsewhere   suffered.       .\ud   wliat  an  amouuc 
of  de^'railation  i«  implied   hy  the  HedimenLarv  deposits 
of  many   countries  [     iVo:es.sor  Kams;iy  ha."  jri^en   me 
tiie   maximum    thickness,   in    most   cases   from    actual 
r.ieasurement,   in   a   few  oa-se?   from    estimate,  of  each 
loruiaiion  in  difierent  parLn  of  (iroat  Britain  ;  and  this 
is  the  result  : — 


I',il.T.'7..u'  etrafa  (not  liKimiliiK  iSTi(^)Ui  l)«l»i 
Tertiary  slriifH  ... 


57, IM 


—  makintr  altoirether  72,.'>B4  feet ;  that  is.  very  nearly 
thirteen  and  tiiree-cjuarters  Hritisli  miles.  Some  of 
the  formations,  which  are  repre.sent©d  in  Knji-Iaud  hy 
tinn  he«ls,  are  thousands  of  feet  in  Ihicknes.s  on  the 
Continent.  .Moreover,  between  ea<h  succes.-.ive  forma- 
tion,   we    have,    in    the   opinion    of    most    ideologist*, 


IMl'KKFKCnON  OF  CEOlAHiii  Al,  HF.( OKI)  255 

eiii.rriii»ti>U  l<"iU  W.aiik  jioriotU.  ."^o  t'.ai  thf  Icttj  pile 
lit  s.'.lnnfiitarv  ^>(•k^  :ti  linlain.  (fives  l.iitaii  ni.i<i«>ijii;i«e 
Hiea  «if  th<>  titiu-  wlixh  /i.-w  ela[.'«-il  ilunni.'  tia-ir 
a.  riimul.it  ;«>ri  ;  \  f»t  wiial  liiin-  liiH  iiiu-^L  h.l\»' fixis.jint'il  ! 
(•otxl  oli'.«'rv«T>i  lla^  P  e«itiniale<l  t)iat  MMliiiu'iit  i*-  il»*- 
|.o-.te<i  h\  th»«  ^rrt-at  Mississippi  rivt-r  at  tlit«  ratr  nf 
oiilv  »;iK"  tfft  ill  H  liiiiulrt'ii  tln>us;ui<l  jimfh.  I  hi'* 
I'.stitnale  lia"  no  prt'teiisioii  to  strul  fxa<-t(.i's«  :  yet. 
ttiii'i.itriiit:  nviTwJiit  widr  spart's  very  niu«  sfilimeiit 
in  triiiisporlnl  by  the  «iirreiiU  of  tlu>  sea.  the  prm-oss 
ot  affumulaMiiii'  lU  a!i>  <iiif  area  mist  l-e  .Mrt-niely 
ilow. 

lint  tVf  nnioiitit  ot  (iemi(iati()ii  wh  r)i  tht*  stru.i  have 
III   mail)   |.l;t«fs  surfori-il.  unlepfiKlei.vi v  (if  the    r.  :«•  of 
u-cuinulatioii   ot  tiii-  deirratled    matlrr,  proialdv  ottVr.. 
tilt'  l>est  evidmre  ot   tlio  lapse  ot  tiiii"       1   reh.cmher 
•  i\inj/  lieeti  iniali  htruck  witli  the  es  iiietict    ot  lieiit.ia 
.,<.ii,  wii»n  \  .fwiatr   volcanic   islamis,  which   have   hefii 
worn    hy    the    waves    and    part'd    ail    r....iui    into   per- 
]  .•ndicular  clitis  nf  one  or  iwt.  thousand  left  in  heiu'ht  : 
■"T  the  treiitle  h1oj»©  of  the  iavastreanis,  d  .e  lo   tln-ir 
:  Tinerly   liquid  sute,  showed  at  a  »rlanre  how  i..r  the 
hirii,  rocky  l>pd.«  had  once  e.xtomipd  into  the  (M>eti  ocean. 
The  name  story  is  still  more   {diinilv  told   h\   faults. - 
•iio-.e  trreat   cn'icks  alonjr    v^hich    the  strata    have  In-en 
,.l,iiea\ed  on  one  siile.  or  llirown  tiown  on  the  '.th^r,  to 
!i.   tieitjht  or  depth  of  thousands  of  feet  :  for  r-mce  tlie 
ri-t   cracked,   the    Burface   of   the   land   ha-    heen    so 
,.ui  plcttdy  planed  down  \>\  the  aiaion  ot  tlie  sea.  that 
no  trace  of  these  v.ist  dislocations  i"  externally  visihle. 
I  lie  (raven   tault.  for  in>tariie.  extends  for  upward;- 
of  :•■>)  miles,  and  alontr  this  line  the  vertical  di»pl.ace- 
rneiit  of  the  stratji   han  varied    from  <;»><•  to  .'Khm*  feel. 
I'rnt.  Ramsay  ha-  puhlished  an  account  of  a  downthrow 
.11  Aiit'leseaof  2;>iM)  feet;  and    he  inform^   me  that  he 
.liv  indieves  there  is  one  in    Merionettishire  of  12. '^K) 
r^i'X  :  yet  ni  tiiese  cases  there  is  nothintr  on  the  suruce 
lo  sliow  sucii  prodiifiouH  nuivrmeiiLs,   ihe  piie  of  ro.  «.« 
■i  the  one  or  other  side  havnisr  heen  sm<K)thlv  f^wept 
4w«v.      1  he  cousideraliou  of  these  fat-ta  impre-^e*-  my 


260 


ON    I  UK   ()KI(;iN   OF   srK(  lES 


Ifl 


mijid    alinoHt  in    thr»   sanip    ni.iiinor  ii>*   •loJ's    tli**   vain 
(MMlfvivmir  til  i_T.i]>|ilt>  with  the  hlfi  iif  ctrniity. 

1  am  t.i  .['tfi!  to  irivc  ohm  'lilirr  i  a-c,  tin-  w<ll  known 
one  (il  ili<«  (l";i>ii!at;i(ii  ot  lim  W CiM.  I  linii.:li  il  must 
'>o  ;iMm;!t«'>l  that  tin- rlriiiKl.ilioii  <.;  th<>  \\  i-al<l  lia-<  Loon 
!i  iinTc  tri  Ic,  ill  ciimiiari-im  v*iti!  that  wliirli  han 
r«'!ii(i\('(l  iii:i>-.r-  ot  inir  j.aia'rt/iiii  -tiita.  in  |>art>*  t»'n 
thoii>.\ti(l  tocl  in  thiikiif-^.  a*  >-hcnvii  iii  I'rof.  I>am-av> 
nla^t<•^l\  in»'moir  0:1  tin-  -ut.M'ct  :  ye'  it  is  an  admir- 
ahlo  I.  ■  i.n  til  «taii'i  un  tlii>  iiitcrmfilia'c  liiliy  j'ountry 
an<l  InciK  iiti  tlic  <Mic  hand  at  tho  Nortli  howns,  and 
on  th«'  fit  her  hmd  at.  1  h(>  ><iii(h  Dowrix;  tor,  rciiiom- 
h«'ri!i:r  thai  at  110  irn'at  di«.t  inco  to  tlif  ^vi'»t  the 
northern  and  soullicrn  esrar|imi'nlj<  moi't  and  « lo>i«*,  one 
can  >at.'lv  jiictiire  to  oaesolt  the  irrcat  dome  of  rocke 
wliich  iiiij'l  hi\o  covered  up  Mie  W  i-ahl  within  bo 
limited  a  |»erind  as  sinre  tli«  latter  part  of  the  (  lialk 
lnrmati<'i\.  Tho  di'.tancp  from  the  northern  to  tlie 
>oiitlicrn  I  >nnns  i~  ahont  2:2  ::::les,  and  the  tliickness 
of  the  s»'veial  formations  is  on  an  average  ahout  lli>» 
feet,  as  I  am  informed  hy  Prot.  llamsay.  Mut  if,  as 
potno  ireohit^ists  siippo-e,  a  ran^'e  ot  c)hier  rocks  lunler- 
lies  the  Weald,  on  the  flanks  of  which  the  overlyini: 
sedimentary  deposits  miifht  have  accumulate'!  in  thin-  vr 
n\asses  than  elsewhere,  the  ahove  c>timate  would  he 
erroneous  ;  hut  this  source  of  doultt  probahly  y:,<nld 
Tiot  irreatlv  atTect  thfl  estimate  as  applied  to  tlie  western 
oxtrcmity'of  the  district.  If,  then,  we  knew  tho  rate 
at  vWiich  liu-  --ea  commonly  wears  away  a  line  of  clitf  of 
any  gWi^u  hoi^'Jit,  we  coiihi  mcisiire  the  time  requisrite 
to  have  denuded  the  \\'eald.  This,  of  courso,  cannot 
he  done  ;  hut  we  may,  in  order  to  form  some  cru<ie 
notion  on  tlie  snl'ject,  assume  that  the  sea  would  e.it 
into  cliiFs  :»(,«)  feel  in  heiirlit  at  the  rat<>  of  one  inch 
in  a  renturv.  1  liis  will  at  first  appear  much  t4.io  small 
an  allowance:  but  it  is  the  s;ime  a^  if  we  were  to 
assume  a  clitf  one  varii  in  nemlit  to  he  eaten  hack 
alouL'  a  w  hole  line  of  c(»ast  at  the  rate  of  one  yard  in 
nearly  e\ery  twenty-two  years.  1  doubt  whether  any 
rock,  even  as  sotl'aa  chalk,  would  yield  at  this  rate 


IMPKRFE(TI()N  OF  GEOIXKJICAL  UK(()KD  247 

eKipliiijf  i»ii  the  m«)«t  *>\(M>i4(>ii  rnantu  ;  thi>ii;r)i  im  (louht 
tliH  detfTadatioii  ot  h  lofty  rlirt  would  lie  mor*-  ia|.id 
from  the  hrt*ak;uf«»  *>f  th«»  fallen  fVajfineiitj*.  < 'n  the 
other  hand,  I  do  not  h«'li»n««  that  any  line  of  coa-xt.  ten 
or  twenty  miles  in  lontrth,  ever  sutferH  detrradatioii  .it 
tiie  Haiiie  time  alone  it^  whole  itidetited  lentrth  ;  and  we 
muKt  reinenUicr  that  almost  all  "itrata  eonfiin  harder 
laven*  or  noduh-*,  whirh  froni  lonu'  resi.stinj;  attrition 
t'orm  a  hrtak water  at  the  ha«e.  We  may  at  leawt 
foiilidently  helieve  that  no  roeky  roast  ."i^x*  feet  in 
heijfhl  commonly  yields  at  the  rate  of  a  fiK>t  per 
ceiiturv  ;  f<»r  ihit  would  l>e  tlie  »arM«'  in  am<»iint  ax  a 
rlitf  one  yard  in  height  retreatiiiir  tw»'lve  yards  in 
twenty-two  yearn  ;  and  no  one,  1  think,  who  h.i>i  care- 
fully oljser>ed  the  shape  of  old  faih-n  fraiimenfx  at  the 
liA>e  of  cliffs,  will  admit  any  n>Mr  a|ipriia(h  to  such 
rapid  wearing  away.  Hence,  under  ordinary  circum- 
stances, I  stiould  infer  tliat  for  a  cliff  ."»(«»  feet  in  heitrht, 
a  denudation  of  one  inch  |>«'r  century  for  the  whidc 
lenjfth  would  he  a  sufficient  allowaiu'e.  At  this  rate, 
Of!  tlie  ahnve  data,  the  denudation  of  the  \\'eald  mu-t 
have  re<jiiired  .'><>•;, »»t)i',4<Hi  y»'ars  ;  or  sjiy  thr«'e  hundred 
million  ye-irs.  liut  jierhafis  it  would  !'»•  >afer  to  allow 
two  or  three  inches  jwr  <'entijry,  and  this  wmild  reduce 
the  number  «>f  years  to  one  hundred  and  fifty  or  one 
hundred  million  ve.irs. 

Ihe  action  of  tresh  water  on  the  trently  im  line<l 
^^  ealden  district,  when  upraised,  could  hardly  have 
i'cen  trreat.  but  it  would  somewhat  ri^luce  the  alntve 
estimate.  On  the  otlier  hand,  durinu  oscillatiotis  of 
level,  which  we  know  this  area  h.is  underjrone.  the  sur- 
face may  have  existed  for  millions  of  years  as  land,  and 
thus  have  escaped  the  action  of  the  st:i  :  w  lien  deeply 
siiltmer;j'e<i  for  perhap-  ciiiially  lonir  perifxls,  it  would, 
likewise,  have  escaped  the  action  of  the  <oast-waven. 
>o  that  it  is  not  improliahle  that  a  lMn:."'(«r  period  than 
•'i<x)  million  years  has  elapsed  nince  the  latter  part  of 
the  Secondary  period. 

I  have  made  these  few  remarks   l»ecau«»©  it  is  hiffhly 
miportaut  for  us  to  g^aiu  Home  notion,  however  ifn[>erfect. 


258 


ON   THE   ORIGIN   OF   SI»E(  IKS 


liM 


of  the  lapse  of  years.  Duriii!,'  each  of  tb^se  years,  over 
U<e  whole  world,  the  laud  and  the  water  has  been 
peopled  by  hosts  of  living  forniK.  N\'hat  an  infinite 
number  of  jfeneralions,  which  the  mind  cannot  gra-ep, 
must  have  succeeded  each  other  in  the  lontr  roll  of 
years  I  Now  turn  to  our  richest  treolo'.'-ical  museums, 
and  wliat  a  paltry  «lisplay  we  behold  I 

'in  I  fit'  jinunieuM  "f  cur  I'uUvdiitnliKjicid  colif  tioriM. — 
ib.it  our  |i.ilifontulot:ical  collections  are  vory  im- 
jxTfect,  is  admitted  by  every  one.  The  remark  of 
that  admiralile  pala'oiitoloirist,  the  late  Kdw.inl  Forbes, 
shoiibl  n(»t  he  lortrotten,  namtdy,  that  numberx  of  our 
f  (ssil  H|i«'i  ics  are  known  and  named  from  sintrle  and 
often  broken  spec'inens,  or  from  a  t'cw  specimens 
collected  on  some  one  spot.  ( )nly  a  Hmall  portion  of 
the  surface  of  the  e.irfh  has  been  p'eolo^ically  explored, 
and  no  part  with  sutHcient  care,  as  the  important  di»- 
coxeries  made  every  ye;ir  in  Europe  prove.  No 
ortranism  wholly  soft,  can  be  preserved.  Sliells  and 
bones  will  decay  and  disappi-ar  when  left  on  the 
bottom  of  the  sea,  where  sediment  is  not  a«-cumiilat- 
inir.  I  believe  we  are  continually  taking  a  nio^it 
ernmeous  view,  when  we  tacitly  admit  to  ourselves 
that  sediment  is  bein«  deposited  over  nea;ly  the  wlioie 
beil  of  the  sea,  at  a  rate  sutticij-ntly  ijiiick  to  embed 
and  preserve  fossil  remains.  TliroiiL'lio'it  an  enor- 
iimiiMy  larf:e  proportion  of  the  ocwiii,  the  britrht  blue 
tint  of  the  water  l>espeaks  its  purity.  The  many  cas<»s 
on  record  of  a  formation  conformably  covered,  after  an 
enormous  iiiler\al  of  time.  l)y  another  and  later  forma- 
ti«)n,  without  the  uuderlyiiiir  bed  tiaviny:  sutl'ereci  in 
tlie  interval  mv  wear  and  te.ir,  seem  exjilicable  only 
on  the  >  lew  oT  the  bottom  of  the  >^ea  not  "irely  lyinjf 
for  aL'e>  in  an  unaltered  condition.  Ttie  reinaiiis 
which  do  liecome  embedded,  if  in  sand  or  gravel,  will 
when  the  beds  are  uprais'.d  generally  l>e  dis-sohed  by 
the  jieri  olation  o.'  .-ain-water.  i  siispe<'t  that  tiut  few 
of  the  verv  many  animals  wlsicli  live  on  the  beach 
betwwn   Li^rl'    *'»!  low  watermark  are  pre.served.      For 


IMPERFECTION  OF  GEOIXXJICAL  I        -RI>  259 

in.uuue,  the  several  Hi.e.Mes  of  the  Tl.t  ...aliim'  (a 
-ub-far  ilv  of  M.shilo  cirrip.xles)  coat  the  ro.-!.  -  all  over 
the  world  in  intinite  uumlK^rs :  they  are  all  vtnctiy 
htt<.ral,  with  the  exception  of  a  Rinde  MediUTraneai. 
-neiies,  which  inhahib*  dee^.  water  and  has  been  tound 
t.w.il  in  Sicilv,  whereas  not  one  other  specie,  ha. 
hitherto  heen  'found  in  any  tertiary  formal..,i.  :  yet  it 
isiiowkiK.wM  Ihattbe  L'cmisC  hthamaluseMsU'ud.irn.- 
the  chalk  i-criod.  The  incdlu.can  Kt'MUS  C  hiton  oHers 
a  nartiallv  anal<>i,M)U!»  ca-c. 

With   respect  to   the   terrestrial    oroducticn.   which 
lived  during  the  Secondary  and   i'alieozoic  periods,  it 
1.  Kui.crduous  to  state  that  our  evidence   trom   fosMl 
rcman.s   is   frajrmenUry   in    an    extreme   detrree.         .-r 
in^tan.  c    not  a  land  shell  is  known  bcloiiKi'i^'  to  either 
of  Mie^e  %ast  periods,  with  the  exception  ot  ono  sj^-cies 
discovered    hv   Sir    ( •.    l-vell    and    Dr.    Dawson    n.    t.u- 
carlK)niferou8  strata  of  North   America,  of  which  slu-1 
heseral  smM-iineii^  have  now  heen  collected.      In  rotfanl 
to    mamnuterous     remains,    a    sinirle    frhuu-ii    at    the 
In-t.-n.  al  taMe  published  in  the  Supplemei.t  to  l.vell  s 
Manual,  will  brintr  home  the  truth,  how  accidental  and 
rare   is    their    preservation,    far   better   than   piures   ot 
detail       N<>r   is  their   raritv   »urj.risintr,   when  we   re- 
meml>er  liow  lar^^e  a  proportion  of  the  hi.nes  ot  tertiary 
mammals  have  been  discovered  either  in  caves   or  m 
l.uiistrine    dep.K.t- ;     and    that    not    a    cave    or    true 
lacustrine   bed  is   known  »)elonKinjf  to  the  atro  ot  our 
M-condarv  or  paheoioic  formations.  ,         •    . 

But  ti.'e  imiMTfection  in  the  ^eoh.^c.al  record  mainly 
re<ults  iVnm  another  and  more  impurtant  cause  than 
anv  (.f  the  mreiroimr  :  namelv,  from  the  several  torma- 
timis  beint;  separated  from  Ciich  other  by  wide  intervaU 
of  time.  \\  hen  we  s«>p  the  formations  Uibulated  m 
written  works,  or  whei;  ve  follow  them  in  nature,  it  i« 
dithcult  to  avoid  liflievintf  that  they  are  closely  con- 
liut  we   know,    for  instance,    from   >i.    li 


>.t'i  utive. 

rviurciiisuii  s   »i'«*ai    w 
tiicre  are   in 
formations  ;   so  i 


.u 


that   rountrv   between  the   superimposed 
i  iH  in  North   America,  and  in  many 


2tM) 


ON    THK    OIUr.IN    OK   SPKCIES 


If! 


I>  ? 


<  1 


1 1 
l< ' 


otlinr  parts  of  the  world.  'Hip  nio^t  skilr'ul  treolotfist,  if 
his  att»?titioii  hail  l»e«Mi  extliisivcly  cnnfiiioH  to  these 
lartre  territories,  would  never  have  siisj>e(ted  that 
•lunriir  the  periods  whiih  were  hl.iiik  and  harreri  in  his 
own  country,  trra-it  piles  of  sediment,  charfred  with 
new  and  peculiar  fonns  of  life,  had  elspwlicre  heen 
areutniilated.  And  if  in  e;teh  separite  territory,  hardly 
any  idea  can  l)e  f<irrned  of  the  lon^'tli  ot  time  wliieh  has 
el.i|ised  between  the  coiiMMMitive  tunuation-;.  we  may 
infer  th.»t  this  could  imwhere  he  a-certained.  The 
fre(|uent  and  irreat  chanji^es  in  the  tniii(»ra!f>L'icai  coni- 
|i  i-ition  of  c»nisecuti\e  tormations.  (."-encralh'  iinpl\'in$r 
^;reat  chancres  in  tlie  ireotrraphy  of  the  surroundintr 
lands,  whence  the  sediment  has  l»een  derived,  accnrd^ 
^v:th  the  l>e!i»>f  of  vast  intervals  of  time  lia\  iriif  e!ap>»'d 
lietwiM'ii  each  formatinn. 

IJut  we  can,  I  think,  see  why  the  ireolojrical  forma- 
tion* of  each  rcLriiui  ;ire  almost  invariahly  intermittent  : 
tliat  i-.  have  not  ;i  'lowed  fach  other  in  close  seijiieiK'e. 
Scarcely  any  fact  struck  me  more  when  examining' 
main-  hundred  mile-  of  the  South  American  coasts, 
Ah  ("h  liavf  heeti  upraised  se\era!  hundred  feet  within 
•he  recent  period,  than  the  al»se!ice  of  any  recent 
deposits  sufficiently  exten«-i\e  to  last  for  even  a  short 
^eoloiric.il  period.  Alon::-  the  v*}iole  west  coa-t,  which 
is  inhabited  hy  a  peculiar  marine  fauna,  tertiary  beds 
are  so  poorly  developed,  that  no  record  of  se\cral  suc- 
cessive and  peculiar  marine  faunas  will  prohably  \k> 
preser;ei!  to  a  distant  aire.  .\  little  re(iecti"M  will  ex- 
|dain  why  iluni:  the  ri-mu  coa-t  of  the  we>t"rn  side  of 
^•outh  .America,  no  extensive  formatituis  witii  recent  or 
tertiary  reniaiii-  can  a:i\\vhere  lie  found,  thoni.'!!  the 
-uoply  of  sediment  must  for  .i;res  liave  been  i:reat, 
from  the  enormous  dcirradation  of  the  coa-t-rocks  and 
from  muddy  streams  enterinj;  the  se.i.  The  explana- 
tion, ii(>  douitt.  is,  that  the  littoral  and  sub-littonil 
deposits  are  continu.i!!v  worn  away,  as  sr^nri  as  they  are 
brouclit  up  li\  the  slow  ami  irradual  risitiir  of  the  laud 
"ithin  the  ^'rindinir  action  of  the  coast.-w;i\  es. 

^^'c    may,    I    think,   -afelv   conclude   that   se<limci;i. 


I 


IMi'KKKECnON  OF  GEOLCHHCAL  RECORD  201 

must   l>e    accumulated    in    extremely    thick,   solid,  or 
extensive  ma>*es,  in  order  to  withstand  the  in.e>sant 
acliou  of  the  waves,   when   first   ui)rai>ed  and   during 
MiU^equent  oscillatHins  of  level.     Mich  thick  and  ex- 
tensive accumulations  of  sediment  may  »'e  forn.ed   in 
t^^o  wav>;    either,   in  protound  depths  ot  the  <ea     m 
wlu.h  ciise,  iudKHM-  from  the  researches  ot   E.  lor  .e>. 
we  mav  conclude  that  the  hott<.m  will   he  mhihited  hy 
i.xtr.-..iclv   few   riti;inal>,  and   the   ma>s  when    upraised 
wiiltfivea  most  iinperlert  recrd  of  (he   lontis  ot   liN 
n-hii  h  then  existeil  ;  or,  sc.iiment  may  l-e  a.curnulate.1 
to  aiiv  thickness  and  extent  over  a  shallow   Uittom,   iJ 
it  c.uitinue  sh.wlv   to  suhside.      in  this  latter  ca-e.  as 
loiiK  as  the  rate  «.V  suhsiaenc-  and   sii].ply  ot  hedimeut 
n.Mrlv  hahmceeach  other,  the  M-a  wul    remain  shallow 
aii.i  favourable  for  life,  and  thus  a  fos^iliterous  torma 
tioii  thick  enoujrh,  when  upraised,  to  rej<ist  any  amount 
of  (letfradat.on,  may  he  torined. 

1    am    convinced    that    all    our   ancient    tormatiomt 
which  are  ridi  in  fossiU  have  thus  heen  formed  durtini 
sut.>i<len<e.     >iuce  puhlishiii»r  my  views  on  tliis  suhject 
in   ia4.').   I  have  wat.hed   the  pro^'ress  of  (ieoloffv,  an-: 
ha\e  t-een  surj.rise.i   to  note  how  autlior  after  author, 
in  trealinu^  of  this  or  th.it  ureat  formation,  has  come  to 
tlie  conclu>ioii  that  it  wa-  accumulat.-d  dnrintr  suhsid- 
eiice.      I  niav  add,  that  tiio  only  ancient  tertiary  torma 
tion   on    i!ie  we>t   c oa-^t   of  South  Ame-ica,  wiiich    has 
heen  Imlkv  enouuli  t.-  r.-ist  such  deirradation  as  it  h.i.-, 
aa  yet  suffered,  hut  whi.li  will  hardly  last  to  a  disUnt 
tri.ol(.m<al  ai'e,  wa-  certainly  dejKiMted   durin^;  a  down- 
w;,r.i  o^ciilaUon  of  level,  an. I  t!iu«  grained  consulerahle 
tliitkno"-. 

All   tr.'oloirical    facts  tell    us   plainly  that   each   area 
has  uncli-r-one  numerous  slow  osriHatioiis  of  level,  and 
apparently  the>e  oscillations  have  ath-.  ted  wide  spate* 
t  on>e'iueiulv  formations  ri<h  in  fo-siU  and  sutliciently 
thick  and  exlmsive  to  resist   Puhse<juent  desfradation. 


.1... 


..1 


1« 


Ilia\    iiave  tirt-n    iOrmC-ti   err   v.;;!i-  •  ;;.;t  r?  tj-^j::::;;    ]• 

of  suh<i.ieiice,  hut  onlv  where  the  ^ui.ply  of  se.limen'. 
wabsulV.ci.-iit  t.)  keep  ''.e  M-a  ■.!:allow  and  to  e-nled  nv-. 


2n'j 


ON     rilK   OincWN    OK   SPKCIK" 


jiit'scrve  tln>!  roni.iiiis  Kcforn  tlicv  liail  tune  to  deca'-. 
<  H\  the  otlitT  haiirl,  as  lomr  as  tlit»  bed  of  the  ^^ea  re- 
mained stationary,  tfiirk  deposits  could  not  have  Ikmmi 
acciiirinlated  in  the  sIimIIow  j>art>,  whii  )i  are  the  most 
!av<iiiraMe  to  life.  Mill  lf>s  could  this  have  haj)[>encd 
diirinjr  the  alternate  iienoiis  of  elevation  ;  or,  to  speak 
more  accurately,  the  Weils  which  were  then  accumulated 
will  have  heen  <ie-.troyed  l>y  heintr  upraised  and  hroujfht 
within  tlie  limits  of  the  coast-action. 

I  hu"  the  treoloirii-ai  record  will  alniDst  ncte^^ir  !v  Jie 
rendereil  intermittent.  I  teel  mucli  coiitidence  in  the 
truth  of  these  views,  for  tliey  are  in  strict  accord. u.ce 
with  the  tferieral  principles  inculcated  hy  Sir  (  .  Lvell  ; 
•iiid  K.  Forbes  sul»se<iuently  hut  indejicndently  arrived 
it  a  similar  conclusion. 

(•up  remark  is  liere  worth  a  passing""  notice.  During 
perioils  of  elevation  the  area  of  tin-  land  and  of  the 
adiuiiiin^'  shoal  j»arts  of  the  sea  will  be  increased,  and 
new  -tations  will  otlen  be  formed  ; — all  circum^tani  os 
most  favourable,  as  previously  e.xplained,  for  the  forma- 
tion of  new  v.-irieties  and  species;  but  durin:,'  such 
periods  there  will  trenerally  lie  a  blank  in  the  >,'-eoloM;i(al 
record.  On  the  other  hand,  duriny  subsidence,  tiie 
inhabited  area  and  number  of  inhabitants  will  decrease 
(except  in«-  the  productions  on  the  shores  of  a  I'ontinent 
when  first  broken  up  into  an  arcliipela^o),  and  conse- 
quently diirin^r  subsidence,  thoutrh  there  will  l>e  much 
extinction,  fewer  new  varieties  or  species  will  be  formed  ; 
and  it  i.-t  durini;  tliese  very  periods  of  subsidence,  that 
ourtrroat  deposits  rich  in  fossils  have  been  ao  umulated. 
Nature  may  almost  be  s.iid  to  have  guarded  a:r:iinst 
the  Jre(|uent  discovery  of  her  tran-itional  or  linking 
'•'rir.s. 

I  roin  t)ie  forejoin:,'  consideration^  it  cannot  be 
doubted  tiiat  the  ireolojfical  record,  viewed  as  a  whole, 
is  extieriudy  imperfect  ;  but  if  we  contine  our  attention 
to  a!i\'  one  formation,  it  becnioes  more  diffiriilt  to 
understand,  why  we  do  not  therein  find  closely 
t^saduaie'l  '.arieties  between  the  allied  species  which 
'  \  «d    at    its  CMin:iieV''<'Mic!it    and    ;it   its    ci(»r%e.      ^o^■;^) 


iMl'KRhE(Tl(»N  OF  (lEOUKlK  AL  RECOKD  2fi3 

ca..'<  :vr»-  on  re.-or.i  of  the  same  ^p^-n.'.  present n.ir 
d.-tiu.t  varieties  in  the  upper  and  lower  parts  otliie 
-ame  tormatic.ii,  but,  as  they  are  rare,  they  may  be  h.;re 
„asse.l  over.  Altiiouch  earh  formation  has  m- 
il..i.util.lv  re.iuired  a  va-t  numher  of  years  tor  it^ 
.iep<»Mti..n,  I  .an  see  se\eral  reasons  whv  each  shouhi 
„t  include  a  graduated  series  of  links  between  the 
.neries  which  tJ.eii  lived  ;  but  I  can  by  no  moans  -tv 
•!.nd  to  a.s-i:rn  due  prop<.rtional  wei-ht  to  the  t..llo«  mir 
considerations.  , 

MllK.utrh  earli  formation  may  mark  a  very  1  uij;  l.ip>e 
:,i  vears,  each  perhaps  is  short  compared  v  th  ti.e  period 
rc.i'uisite  to  chanire  one  snecie^*   nito  .ui..iher.       i  •'•ni 
*w!ire    that   two   i>ala^untoloirists,    whose    opiniona   are 
worthv  of   much   deference,  naniel,    Bronn  at  d   U  ood- 
*ara    have  concluded  that  the  aveni^re  duration  oi  each 
form'itiou  is  twice  or  thrice    as    Ion-    a^   the  aveni^e 
duration  of  specific  forms.     But  insuperal)U>  dithculties, 
an   it   seems    to   me,  prevent   us   cominjf     to    any  just 
.onclusion  on  this  hea.h      When  w.    see  a  species  hr^t 
aupeannjf  in  the  middle  of  any  formation,  il  wo<ild  \>e 
ra.sh  in  the  eitreme  to  infer  that  it  had  not  elsewhere 
previously  existed.      So  a^rain   when  we   find   a  xp.-.ies 
disappearing?  before  the  uppermost  layers   have    been 
deposited,  it  would  l.e  equally  ra-h  to  suppose  that  it 
tiien    }«H-ame  wholly  extinct.      N\e    fortret  how  small 
the  area  of  Europe  is  compared  with  the  rest  of  the 
^orld  ;  nor  have  the  several  stajres  of  the  same  f<ima- 
tion  throughout   Europe  been  correlated   with  pcriect 
incuracv. 

With'  marine  animals  of  all  kii.d-,  we  may  safely 
inter  a  larpe  amount  of  miu'-t^tion  during  chmatal 
xxid  othrr  cluujres  ;  and  when  we  see  a  -pecie^  first 
;ipiK'a-iii-  in  any  formation,  the  pn.bability  is  that  it 
..nlv  then  first  immi^rrated  into  tliat  area.  It  is  ^vel 
Known,  for  instance,  that  several  species  appcired 
m,mewiiat  earlier  in  the  jKiIwozoic  beds  of  North  America 
than  III  those  of  Europe  ,  Lime  ii-i^.r.t;  5j.}>.»rr::t:y  ^n 
required  for  their  miurntion  from  the  American  to  the 
KuroiKjan  se^w.       In  examining  ttie  latest   deposita  of 


2*>4 


ON   THK   OIlKilN   OF   SPEC  lES 


lH 


viiridijs  fjiiarters  of  the  worlil,  it  has  pvfirvwhere  U^n 
iiotcri,  that -nnie  f'«'w  still  exivtin^r  Hptv-iuN  are  rommnri 
in  the  <i»'[M)-it,  but  have  l»«(<)me  extinct  in  the  immedi- 
ately -^urniuiwliiitr  sea;  or,  roiivt'r-.'ly,  that  «ome  are 
now  al)umiaiit  in  the  iiei^jhlKturiiiif  -t':i,  hut  are  ran-  or 
ahseiit  in  this  p.irtinil.ir  (leposit.  It  is  an  exrellent 
lesson  to  rt'tlfct  <>:i  the  ascertained  amount  of  niitrrati'if. 
«»t  the  inli.iliitant".  ui'  Kiiroj>e  diiriiiir  the  (ilacial  period, 
whicli  tortus  only  a  i»art  of  oin'  w  nole  L'eolotrical  period  ; 
and  likewise  to  r.tlcct  «»n  the  (rreat  changes  of  levnl, 
on  the  inordinately  (rreat  ctiantre  of  climate,  on  the 
prodi-ious  lapse  of  time,  all  ini  Itided  within  this  same 
fflaci.ii  perio.l.  ^  et  it  may  he  douhted  wlu'ther  in  any 
<]uarter  of  tlie  world,  sedinientary  deposits,  inrludtrin 
fotnil  remahis,  have  pone  on  accumulatimr  within  the 
saoio  areaduriiii:  the  whole  of  ttiif.  |H!ri(»(i.  It  is  not.  tor 
inKtancp,  proltabie  that  sediment  was  deposite«I  durine^ 
the  whole  of  the  jrlacial  period  near  the  month  of 
the  MiRsissipjn,  withni  that  limit  of  depth  at  whii  h 
marine  nnimals  can  flourish  ;  for  we  know  what  vast 
jreoeraphifril  rhaneeso<curre(i  in  other  parts  of  America 
during  lliis  space  of  time.  \V  hen  such  }<<><ls  as  were 
deposited  in  shallow  water  tuvir  the  mouth  of  the 
Mississippi  during  some  part  of  the  glacial  |>eriod  shall 
have  hcen  upraised,  ortranic  remains  will  [iro'twihly  first 
appe.'ir  and  di8apj)ear  at  different  levels,  owinjf  to  the 
migration  of  species  and  to  ireotfraphical  chantres.  .\tid 
in  the  distant  future,  a  ireol<»L'-ist  examining  these  l)eds, 
mieht  1)6  tempted  to  conclude  tliat  the  avcraire  duration 
of  life  of  theemlH»dded  fossils  had  U^en  less  than  that 
of  tlie  fflacial  period,  ins-tead  of  haviriir  hcen  rr  ally  far 
irrcator.  that  is  extendiuir  from  before  the  f^lacial  epoch 
to  the  present  day. 

In  order  to  i^ct  a  perfect  trradation  betwcri-  t.vo  forms 
in  the  upper  ami  lower  jKirtsof  the  same  formation,  the 
de|>osit  must  have  g'one  on  accumulatinjj  for  a  very  lonif 
period,  in  order  to  have  jriven  suthcii-nt  time  for  the 
slow  process  of  variation  ;  lience  the  deposit  will  jretier- 
ally  have  to  be  a  very  thick  one  ;  ami  the  spociix* 
undcrffoirijT  modifi<-at:on  will  have   h.i.i   to  l.^e  on  the 


^m^ 


\ 


iMI'KRFECnON  OK  (;K(>I/K^iICAL  REt'ORP  264 

^»me  ar*"*  throughout  this  whole  time.  liut  we  have 
M-i'U  tliat  a  thick  fo^^Mlitrrous  formation  can  onl\  l« 
a.-.Mimwlatril  diiriiifr  a  p'TJod  of  suhsi.h'iice  ;  and  to  ket-p 
the  .i.-l.th  ai.proximat.-iv  the  Hanie.  whi.h  is  nf'«-.«ss;iry 
i,.  nrrU'r  to  ♦■nal-le  tlie  same  Hi>e<-ies  to  hve  on  tio-  -ame 
,t,;..-..  the  ^iipi.lv  of  s.dimeiit  must  n.-arly  have  cnunter- 
■sii.ui'.e.i  the  Mmount  of  siil.Maence.  But  thi-.  same 
niovment  ..f  -Ml.M(leu.e  «ill    often    tend   to  sink  the 

ir.M  w},.-n.e  tl dimei.t  is  drrivi-.i,  and  thus  dimansi. 

•1„.  Mi|.|.lv  whilst  the  downward  movement  eoiitinues. 
In  fa.t.  tiiis  n.arlv  exact  halan-in-  l.etv»een  the  suj.|.  y 
d  ..Miiment  and  the  amount  of  sul.Mdence  is  i>rolai)ly 
irir.Tuntinu'emv  ;  f..r  it  h;i>  he.-n  oh-erved  hy  more 
than  on..  i.aheont..lntr;st.  that  very  thick  deiKi-its  are 
o^iiallv  kirren  of  orirani.  remains,  exc.-pt  near  th.ir 
lij.per  <ir  lower  limit-. 

it  would  M-em   that  .-ach  M'parate  formation,  like  tlie 
A  hole  pile  of  format  :nns  in  any  ...untry,  fa-  ueneralh 
.*en  intermitteni  in   its  aetniP-.ulation.      \V  hen  ^•;  -«e, 
a.^   1-  ^o  often  th.-   cJi-^e,  a   f..rmalion  .-omp—ed  ot  UmIs 
of  .litT.rent   miii.rr.lotfical  ,om|..»sit:nT,.  we  may  reason- 
«  ilv  -uM.ect    that    the  pro.-e.ss  of  depu-ition   lia.s    hven 
mil',  li  -nterrupt.-.i.  as  a  .liani.'.-  in  the  currents  of  the 
-.M  and  a  supply  of  -..dimenl  of  a  diiT.Tent  natur.'  will 
zeneraliv     have'  been    <lue    t<»    fr,.,.trraphi.vil     changes 
re.jnirinir  much  time.     N..r  will  the  .lo-.-^t  inspection  of 
a  formation  give  anv  idea  of  the  time  which  its  deposi- 
tion has   .-on-umed.     Manv  instances  could  he  ^nven  of 
lH>dsonlv  a  few    Let   in  thickne>s,  rcpre.-.entii:>r  forma- 
tions, el'sewli.Te  thousands    of  feet   in  thickness,  and 
which  must  liave  reijuir.'.!  an  enormous  period  for  their 
;ucumulation;  yet  no  on.-   i;fnorunt  of  tins  fact  would 
have  su>p.M  ted  the  va.st  hip-e  of  time  represented   hy 
ti.e  thinner  formation.      .Man)  cases  <ould  l»e  jfiven  of 
tlie  lower  heds  of  a  formation  liavinij  heen   uprai<e«i, 
d.'nialcd.sut.ine.-^-ed,and  then  r«^covered  hvthe  tip|„r 
Ks'ds  of  the  vame  formation,      fari.-,  >.ho»inu  what  w;d.-. 

accunuiiation.      lu   other    ca>es    we  have  the    plainest 
evidence  in  irreat  fo-ilised  tre*'s,  stHl  standiiiT  uprmhl 


20<; 


ON    IHK   OKKJIN    OF   S1'K(  IKs 


a- tlicy  ^'rf\r.  f.f  many  loiiu'-  intervals  of  time  and  ch.injfes 
of  h'vrl  .liiriiiir  tlip  process  of  deposition,  whirh  would 
n<ver  t'vi-n  hav«  l,.M-n  sii<i.»'(t«-d,  had  not  tlie  tr.-es 
rliancj'd  to  hav«'  I..'.ti  t.r.-scrvcd  :  tlin>  Messrs.  Lyt'Il 
an"i  I),iw<on  toiiiid  tarlionifcroiis  beds  M(m»  feet  thick 
m  Nova  Scotia,  with  ancient  root-F)earin;r  strata,  one 
al>o\(«  the  other,  at  no  less  than  M,ty-«i^ht  different 
levels.  Hence,  when  the  same  species  (M-riir  at  the 
l>ottoin,  middle,  and  topo'a  formation,  the  prohahility 
IK  that  they  have  not  lived  on  the  >ame  s[)ot  during  the 
whole  period  or  drjM.sition,  hut  have  disappeared  and 
reapi-cared.  perhaps  many  times,  duruiir  the  -ame  jfefH 
loiTical  periu.i.  So  that  if  such  sj.cfies  were  to  under-ro 
i  coiisideralue  amount  of  modification  durintr  any  one 
u^'olo^firal  period,  a  section  would  not  prohahly  in'clii<le 
all  the  tine  intermediato  (gradations  which  must  on  my 
theory  have  existed  het«een  th.-n,.  hut  ahruj.t,  thoui^h 
perhaj)s  very  sli^rJit,  ch.infres  of  form. 

It  ii  all-iiiiport/iiit  to  rememher  that  naturalists  have 
no  iiolden  rule  hy  which  to  distinguish  species  and 
varieties  ;  they  {rrant  Home  little  variahilitv  to  each 
species,  hut  when  they  meet  with  a  somewhat  jrreater 
amount  of  difference  hetween  any  two  forms,  they  rank 
hoth  as  species,  unless  they  are  enabled  to  connect  them 
U)}rether  hy  close  intt'rmediate  pradalioiis.  And  this 
from  the  reasons  just  assiCTied  we  can  seldom  hope  to 
effect  in  any  one  jreolojncal  section.  Supposing;  H  and 
("  to  Ihj  two  sj.ecies,  and  a  third,  A,  to  he  found  in  an 
underlyinff  hed  ;  even  if  A  were  stri(  tly  intermediate 
'.etwoen  H  and  (  ,  it  would  simply  he  ranked  as  a  third 
and  distin<-t  species,  unless  at  the'same  time  it  could  be 
iiio-t  closely  connected  with  either  one  or  both  forms  bv 
iiii.rmediate  varieties.  Nor  should  it  be  for^rotten,  as 
I'cfore  explained,  that  A  miirht  be  the  actual  progenitor 
•  r  M  and  (  ,  and  yet  mit:!it  not  at  all  necess.irily  be 
strictly  intermediate  hetween  them  in  all  pc.ints  of 
structure.  So  that  we  mijrht  obUiin  the  parent-sT>ecips 
anii  it.s  several  modified  descendants  from'the  lower  and 
iipl)er  beds  of  a  formatioji,  and  unless  we  obtained 
riu.'Mer.. 's  ttansition.J  ^:,.f  aUw^,  we  should  not  irco^f- 


1 


IMl'KRKKCTION  OK  r.y.Ol/MMC  AL  IIK( OKI)  207 

..  ,..   thoir   n'Ution-hip,   .'"..1    should    con.o.juently    l-e 
;  .,:n,M.ll...l  to  rank  th.-rn  all  as  distm.-t  '"r;T^.^ 

It'is  notorious  on  v.hat  excessively  sl.uht  d.fferen.-.- 
„,;.„vi.al:.'ontolosri^t- have  founded  tlieir  spenes  ;  and 
,h..v'd..  this  tl...  mnn.  readily   if   the  specimen-  n.me 
.ru,n  .li.rer....t  sub-Ma.M-s  of  the  same  formatu.n.     Some 
..M.eiien.-ed  .on.  hnin-ists  are  now  sinking  inan>  ot  the 
V  vie  spe.-it.s  of  in  )rhi.^ny  and  oth-rs  mto  the  rank 
ot7ar:eli.-.  ;  and   on   this  view  we  do  hud   the  k.nd  ..: 
,.,„,,„,.  „t  rhan.^e  ^vhi.h  on  my  theory  wo  outfht    o 
^nd      M<,re..v.r,  ir-N^elook    to  rather  w,der  intervaU, 
„.,nelv.  to  distinct  hut  couHe<-utiv^  Htnire.  of  the  san-o 
M-eat  t..r,n.ti..n.   ^e    fuu\  that    the    emhe.l.ied    toss  U 
th..u,h    almost  ,.n.ver<ally  ranked    as  .peclically  dJ- 
fercnt    vot   are   far   more   ch.sely  alued    to  each   o'hrr 
than  are  the  species  foun<l   in  im.re  widely  se,«rated 
forn>ations  ;  hut  to  this  ...hject   I  shall  have  to  return 
in  the  tollowiiii;  chapter.  •  i        •       i 

( ,„..  other  ronsiderav.on  is  worth  notice :  with  animals 
ind    i.lants    that    can    propii^ate    rapidly   and  are  not 
hi-hlv  locomotive,   there  is  rea.son  to  sus{«M-t,  a>    we 
ha*"ve  iorn.erlvseen,  that  cheir  varieties  are  ironerally  a 
iTst  local  ;  and  that  su.h  lo.al  varieties  do  not  spread 
widelv  an<l   supplant  tlieir  parent-forms  until  they  Have 
h,.,M,    n.u.lifie,!    and    perfected    in    some    considerable 
.•,.^r..e      Accordinu'  to  this  view,  the  chance  of  dtscover- 
inR  in  a  for.natmu  in  anv  one  country  all  the  early  stages 
,.f  transition  between  anv  two  forms,  is  small,  tor  the 
su.-.essivpchanires  are  suppose<l  to  have  been  local  or 
,-,   nned  to  some  one  spot.      Most  marine  animals  have 
•i   vide  nm^e  :  and  we  have  seen  that  with  planta  it   is 
thwe  which  have  the  widest  ranjre,  that  oflene.st  present 
,  .rieties  •   «o  that  with  snells  and  other  marine  animal-, 
I  is  probably  tViose  which   have  had  the  widest  rniiire, 
•  ;r'exc.T,i  III,'  the  limit>  of  the  known  ffeolosical  }..rm:i- 
tiuns  of   Knrope,  which  have  oftenest  jriveu  rise,  hr>t 
to  local   varieties  and  ultimatelv  tone^-  specie  ;  and 
thi-i  a^ain  would  jrreativ  iesseii  liie  chrti..  o  or  i>:;r  ;:riiiu 
ii)lo  to    trace  the    stages     of   transition    in    ciiy    one 
'eo'o:  i-;t!  forinat'ofi 


2(» 


ON   THK   OKKilN   OF   M'ECIKS 


;? 


It  Hlioiild  not  he  forgotten,  that  at  the  prenent  dav 
with  i..Tf.vt  spenmoiiH  for  exaniiiiati..ii,  two  t(,rm«  carl 
«eJ.Jom  be  .omioctr.l  l.v  interm.'diate  varieties  and  thti« 
prov.Mj  t..  l>e  the  sam«  ^porie-s,  until  manv  snerimen- 
bave  U.,.n  rollerted  from  manv  p!a. v.s  ;  and  in  the 
<a«e  of  fossil  Hpeoies  this  could  ran-lv  he  effected  bv 
pai;v„ntol(,i:i,t..  We  shall,  perhap>.  Ik^I  perceive  the 
iriiprohahility  of  our  i.einjr  enahh-d  to  connect  npe.iet. 
by  iMimeroiis,  tine,  intermediate,  fossil  ]i„ks,  bv  asking 
ourselves  wln-iher,  for  uist.ince.  ceoloyi.f.s  at  some 
future  jM'riod  will  l>e  able  to  prove,  tliat  our  different 
bre.-d.  ot  cattle,  sheep,  horses,  and  d..-s  have  descende.l 
from  a  si  rifle  Kto«-k  or  from  several  ahoricm.-ii  stocks- 
or.  airam,  uliether  certain  sea-hhells  iniial.itin^r  the 
shores  of  North  America,  which  are  ranked  l.v  some 
concholoiTi^ts  as  distinct  spe.  ies  from  their  Kur..i,ean 
repreMM.tatives,  and  by  other  con.-holo^nsts  a.s  onlv 
var..-ties  are  really  varieties  (.r  are,  as  it  is  called' 
Kptcirically  distinct.      1  his  .-ould    he  effected   onlv   hv 

tie  future  ^reMlot:istdiscoverin»r  in  a  fossil  st;itenumJrous 
;nterme<liate  >:radati.»n.s;  and  such  huccckh  seems  to  me 
imfiruhahle  in  the  hitrhest  detfree. 

iM-olotfical  research,  thou-h  it  has  added   numerous 
species  to  existirij,'  and  extinct  genera,  and   has  made 
the  intervals  between  some  few  g^roups  less  wide  than 
thev  otherwise  w(.uhl  have  heen,  vet  has  done  scarcelv 
uiytl.in^f  m   hre;ikin:,'   down    the  distinction    iKJtweeh 
-^I'c.ies,    by  connectinff    them   together   l.v    numerous 
tin.-,  intermediate  varieties;  and  this  not 'havin^r  heen' 
erfected,  is  prohahly  the  >rrave>t  and  most  oI.mous  of 
all  the  many  objections  which  may  he  ur^red  aijainst 
'ny  Mews.      Hence  it  will    ho  worth   while   to  sum   up 
the  t<.re:r(.intr  remarks,  under  an  imadnarv  illustration 
Jhe  .Malay  .Vrchipela-(.  is  of  about  the  size  of  Kurope 
from  the  N..rth  (  ape  to  the  Mediterranean,  and  frot. 
Hritain   to   Russia;   and   therefore  equals  all   the  ^eo 
I'.trical    formriti«.ns    which    have    l.een    examined    with 
a:, y  accuracy,  excej.tin^'  those  ot  the   I  nited  Mates  of 
America.       I    fully    a?rea   with    .Mr.    (iodwin •  Au>ten, 
that   the  j.resent  condition  of  the   Malav  ArchijK'laiTo' 


MI'hKFECTION  OK  (iKOlAXiU  AL  Kfc(  OKI)  269 

v^ilh  its  numen..is  1  .n:P  islandn  separated  by  wide  and 
-J.allow  8«is  prul..it.lv  reprrMM.ts  tho  tormer  statn  of 
Kun.pe,  whilst  m..>t  of  our  formations  Hor«  ac.umu- 
ati.ii  Tho  Malav  An-lupchMfo  i.s  one  of  the  richest 
r,..ri,„;s  of  the  whofe  >*orhi  in  orjfauic;  hew.jfs;  yet  it  al 
■C  .mM-if.  were  to  b«,  onUe.-ted  v,hi.-h  hase  ever  Ined 
tlu-re.how  imperfectly  would  they  represent  the  n.itural 

•  ii^torv  of  the  world  '  ,    .  .1      . 

Mat' wo  haveeverv  rea.s<.n  to  V»elieve  that  the  terren- 
tna!  nrod.H-tioiis  of  the  arrhipela-o  would  In-  pr.-.erved 
it,  an  ex.  .-HMvelv  imperfect  manner  m   tho  formations 
svhM-l.  v^e  suppu.'e  to  U  there  acrumulatun:.         su^pe^t 
that  not    manv  ..f  the  stri.tly   littoral   animals,   or  o 
,l,n.e  whi.h   lived   on   naked    Mihmanne   nu-ks,   nuul.t 
t,..  ..mt.edded  ;  and   those  einhedded  in  t-ravel  or  sjuid, 
would  n..t  endure  to  a  .listant  ep<Hh.      U  herever  sedi- 
ment did  not  a.Tumtilate  on  the  l.ed  of  tho  sea.  or  where  ,t 
.li.l  ,i.,t  accumulate  at  asutRcient  rate  to  protect  orir:i,nc 
K„.li,.^  from  de.av,  iw  remains  could  he  pre-erved. 

I  hel'.-ve  that  t".'.ssilifen.u>  formations  could  he  t..rm.vj 
HI  the  arrl.ipei:iir<..  «t'  thickness  sufficient  to  hist  to  an 
■i.re   i^  di-tant  in   futurity  as  the  second;-ry  tormatioiir 
lie   in    the    past,   onlv   duriujf    p-riods   ol    suh-idence 
•I-h,..e  t.eri.Hls  of  suhsidence  wc.uld   ho  separated   from 
.-uh  other   l.v  enormous   intervals,  durin-   which   the 
area  would  he  either  st:iti(mary  or  risinir ;  «h  Ut  risins:, 
each  fo->iliforou-.  formation  would  he  destroyed,  almoNt 
ts  soon  as  accumulated,  hv  the  incess;int  co;uit-action. 
.IS  we  now  see  on  the  shores  of  South  America.     I>unnt.' 
the    peri'xis   of   suhsidence    there   would    prohahlv   be 
much  extinction  of  life;  durinjr  the  periods  (d  eleva- 
tion, there  would  he  mu.h  variation,  but  the  treoloirical 
record  would  then  he  lea-t  perfect. 

It  miy  he  douhted  vvhether  the  duration  of  any  one 
Teat  period  of  sulKid.'iice  over  the  whole  or  part  of 
the  archipelairo,  to-ether  wih  a  contemporaneous  accu- 
^,,.  !.<;..!!  of  w.flim.'i.t.  would  ejrret-ii  the  avenure  dura- 
lion  of  the  siime  >pec  tic  forms;  and  these  contintrencie.s 
are  indispensahle  for  the  preservation  of  all  the  transj- 
tional  uTadaiions  between  any  two  or  more  species       If 


MICROCOPY    RESOLUTION    TEST    CHART 

AN'^i    .ind  ISO  TEST  CHART  No    2 


1.0 


I.I 


1.25 


1^      2.8 

2.5 

u.  m        2.2 

!:  m 

t  a- 

2.0 

i_ 

i_ 

1.8 

1.4 

1.6 

^     x^PPLIED  IM^GE 


•er.   Ne«   "o'k        1*6 
*82  -  0300  -  Phone 
^'88  -  5989  -  Fa. 


270 


ON   THE   ORIGLN   OK   SPECIfcS 


hiirh  trradatioiis  were  not  fully  prestTved,  tr.nisitional 
varieties  would  merely  apiM-ar  as  so  many  distinot 
Kpccies.  It  irt,  al^o,  prohalde  that  each  threat  period 
of  Kuhsiiloiice  would  lie  interrupted  by  oM-illations  of 
level,  and  that  sli>rht  cliiiiatal  chan;;e>  would  intervene 
durin;;  such  lengthy  periods  ;  and  in  thcM?  cases  tlie 
inliahitants  o.*"  the  arrhi|>el;uro  would  have  to  niiirrale, 
and  no  closely  consecutive  record  of  their  modiricatioiw 
could  he  preserved  in  any  one  fornmtion. 

\ery  many  of  the  marine  inhaliitants  ol  the  archi- 
|»elaj;o  now  rariire  thouKiimls  -f  miles  beyond  iU  con- 
tines;  and  anal(.f,n-  leails  me  t(»  believe  that  it  would  be 
diiefly  theM>  far-raniriii;r  >po.i,.s  which  would  oflenest 
produce  new  varieties  ;  and  the  varieties  would  at  tirst 
L'tMierally  be  local  or  confined  to  one  place,  but  if 
posse^ised  of  any  decided  advant;ure,  or  when  further 
niodihed  and  improved,  they  would  slowly  spread  and 
supplant  their  jKirent- forms.  When  such  varieties 
returned  to  their  ancient  homes,  as  they  would  dirter 
from  their  former  state,  in  a  nearly  uniform,  though 
perha])s  extremely  sliirht  dejfree,  they  would,  accord- 
intr  to  tJie  principlt^is  ffdlowed  by  many  pala-ontolo^ists, 
be  ranked  as  new  and  distinct  species] 

If  then,  there  be  some  dcirree  of  truth  in  these 
remarks,  we  have  no  rijrht  to  expect  to  find  in  our 
j^eological  formations,  an  infinite  numWer  of  those  fine 
transitional  forms,  which  on  my  tlieory  assuredly  have 
connected  all  the  past  and  present  species  of  the  same 
jfroup  into  one  lonj;  and  branchintr  chain  of  life.  We 
outrht  only  to  look  for  a  few  links,  some  more  closely, 
some  more  distantly  relatt'd  to  each  other  ;  and  the.^e 
links,  let  tliem  be  ever  so  close,  if  found  in  different 
st;i^'-es  of  the  same  formation,  would,  by  most  palieonto- 
loa-ists,  l>e  ranked  as  distinct  species.'  Hut  1  do  not 
pretend  that  I  should  ever  have  suspected  how  po-.r 
a  record  of  the  mutations  of  life,  the  best  preser\e(i 
teoloLMcal  section  prasenttxL  bail  not  the  'litlicultv  of  nur 
not  discovering  innumerable  transitional  links  between 
the  spei'ie*.  which  apinvired  at  the  commencement  and 
clo.se  of  ivicli  forniation.  prcjvsed  so  hardly  on  my  theory. 


■■■*»•!» 


IMPERFECTION  OF  GEOUMiK  AL  KECOKD  271 

(m   the  Hidden   af>}>^iir'ince  uf  whole   ijronpi  of  Allied 
Sperien  — Tlip  ahrupt  maimer  in  wlii.-h  whole  ffroups  of 
S.ecie«  suddenlv  Hi.i..-.-ir  \n  certain  furmations,  has  het'u 
urce«l    by    s.-veml    paliPontolo^isL-^   -  for    iiistatire,    by 
Xtrassiz/l'ictet.   and   hv   none   more    forcibly    than   bv 
I'rofessor  Sedtrwick-as  a  fatal  objcrtioti  lo  the  h.-li-t 
in  the  transmuUtion  of  sptMies.      If  numerous  spe.ies, 
l)eloiurinir  lo  thi-  same  K«nera  or  tamilies,  have  really 
started  into  life  all  at  ouce,  the  fact  -ould  be  tatal  to 
the  theory  of  descent  with   slow  nio<iifHation   throujrh 
natural  seWtion.      For  ti-.-  development  of  a  trroup  o! 
forms,   all   of  which    have   des.ende.l    Irom    some   one 
j.rosfenitor,  must  have  been  an  extremely  slow  process; 
'md  the  protfeuitors  mw>l  hav,-  live-l   ionK  ••«!:•'>   "*'^'""e 
their  mo.litied  descendanti?.      Hut  we  continually  <)ver- 
rate  the  i>erfection  of  the  treolojjical  record,  antl  falsM'ly 
infer,    because    certain     ireiiera    or    families  have    iiot 
been    found    beneath    a    certain    -t.ure,    that    they    did 
not   exist   l.ef(.re   that   sta*re.       U  e  continually    tortrel 
how  lartre  the  world  is,  comjKired  with  the  area  over 
which  our  ^eolotrical   formations   have  been  caretuUy 
examined  ;  we  for^^et  that  irroups  of  si)ecie.-  may  else- 
where have  Ion?  existed  and   have  slowly  multiplied 
l)efore    they    invaded     the    ancient    archipeluAroes    of 
Kuro|>e  an.'i  ot  the  I'nitwl  States.      W'e  do  not  make 
due  allowanco    for   the   enormous    intervals    of   time, 
which  have  prol>ably  elapsed  l»ctwe'>n  our  consecutive 
formations, -lonirer  i)eriiaps  in  most  cases  than    the 
time  required  for  the  accumulation  of  each   formation. 
ITiese  intervals  will  have  jriven  time  for  the  multipli- 
.ation  of  s|)eoies  from  some  one  or  some  few  jKirent- 
forms  ;  and  in  the  succeedinif  formation  such  sjK'cies 
will  apjHVir  as  if  suddenly  create«i. 

1  may  here  recall  a  remark  formerly  made,  namely 
that  it  iuiKl't  require  a  Ion?  succession  of  a;res  to  adap- 
an  organism  to  some  new  and  jH'culiar  line  of  life,  ti»r 
inKl-anee  to  »lv  thniiiirh  the  air;  but  that  wiien  this  ha<l 
\ieen  effected,  and  a  few  species  had  Ihu-.  acquire<l  a 
uTeat  advaiit-;ure  over  other  ortrani^m-,  a  comparatively 
short  time  would  be  necessary  U»  province  nianydivrrireu* 


mm. 


wm 


272 


ON   THE   ORKJIN   OF  SPECIES 


H 

•I 

ji 

4 


form8,  which  wouhl  l»eahie  to  spread  rapidly  and  widely 
throutrhout  the  world. 

I    will   ijow  ^ive  a   few  exanipjes  to  illuntrrite  these 
remarks,  and   to  sliow  iiow  li.ible  we  are  to  error  in 
siipposiiiiT  ih.it  whole  trnMjps  or  sjK'i-ips   |i:t\e  suddeiilv 
been  pro.luoed.      1  may  recall  the  well-ku(»wii  tart  that 
in   {feol();riral  treatises.  puMislied  not  many  vears  at,^o, 
the  trr<>;it  class  of  mariiin.-i!s  wa.s  ahvays  hpoken  of  a^ 
ha\  int'  abruptly  come  in  at  the  commencement  of  the 
tertiary  series.      And   now  one  of  the  richest  kn«)wu 
accumulations    of  fossil    mammals,    for  its    thickncns, 
l»elon!.'s  to  the  middle   of  tlie   secondary  sei   .'s  ;    and 
one  true  mammal  him  been  discovered  in  the  new  re«l 
handstone  at  nearly  the  commencement  of  this  throat 
series.      Cuvier  used   to  urye  tliat  no  monkey  occurred 
in  any  tertiary  Htrattim  ;   but  now  extinct  siHjcieM  have 
been    discovered    in     India,    South    America,    and    in 
Kurojie  even  as  far  l»ack  a.s  'tie  eocene  stitre.       Had 
it  not  been   for  the  rare  accident  of  the  preservation 
of  footsteps  in  the  new  red  sandstone  of  the   I'nited 
States,    wlio    would    have    ventured    to   suppose    that, 
besides  reptiles,   n,,  less  than  at  least  thirty   kinds  of 
birds,  some  of  tfiarantic  size,  existed  durinj,'  that  period . - 
Not  a  frag-ment  of  bone  has  been  discu\ered  iu  tliese 
ImmIs.       Notwithstandiiiir    tliat    the    number    of    joints 
siiown   in   the   fossil   impressions  c«)rrespond   with      he 
nuniU'r  in  the  several  toes  of  living  birds'  feet,  some 
authors    doubt    wliether    the   animals    which    left    the 
impre-sions   were   really   birds.       I  ntil   .juite   recently 
these  authors  mit^lit  have  maintained,  and  some  have 
maintr-iined,  that  the  whole  class  of  birds  came  sud- 
denly into  existence  diiritiir  an  early  tertiary  period  ; 
but  now  we  know,  on  the  authority  of  "rofessor  Owen 
(as    may    !«•    seen     in     Lyell's     Mnuwil),    that    a    bird 
certainly    lived    during    the    deposition    of   the    upper 
ifri'i'iisiuid. 


I    ni:iv   trive   aiiotiisr    In-^.tHnfe     ifb!:'}-. 


from 


•i?i- 


passed  under  my  own  eyes  has  mudi  struck  me.  In 
a  rtiemoir  on  Fo>sil  .Vssile  (  irrif)edes,  I  have  stated 
tliat,  iroin  the  numl)er  of  esiHtinif  and  extinct  ti>rtiary 


IMl'ERKECnuN  OK  iiE*)U)GlC:AL  KE( OKI)  273 

frtim  tli»>  I'xtraortlinary  rit»undatu-e  of  thp  mdi 


»p<'».ie«  ; 


ill 


the 


the 


worltl,  trom 
Arctic  regions  to  the  e<iuaU)r,  inhabitinjr  various  z«men 
i.r  depths  from  the  upjxT  tidal  limit-*  to  .'>»<  tathoniH  ; 
torn  the  perfect  manner  iii  which  xj^M-imen-*  are  pr»*- 
-iTved  in  the  oldewl  tertiary  heda  ;  from  the  ea>e  with 
which  even  a  fragment  of  a  v:ilve  can  l>e  re.  ..irnis<'<l  ; 
from  all  these  circum«t.iiu-es,  1  interred  that  had  sesnile 
oirripedoH  existed  (luriii>f  the  >econdary  i)erio<lH,  they 
vrotil'l  certainly  have  been  prefer ve«l  and  diwovere*!  ; 
and  a:*  not  one  species   had   then    been   discovered  m 
l.edB  cf  this  a^e,  1  concluded  that  this  j^reat  jfnmp  liad 
tK?en  suddenly  developed  at  the  commencement  of  the 
tertiary  serie**.      'nii-*  «»-•*  a  ^ore  troulde  to  me.  addiiii.' 
as  I   thought  one  more  instance  of  the  al.rupt  ;inpear- 
ance  of  a  srre^t  trroup  of  siiecios.      But  my  wnrk  had 
L.vrdly  »>een   puhli-lied,  when  a  skilful   paUontnloifist, 
M.  Hosquet,  sent  me  a  dniwiii^'  of  a  perie.-t  sp*M-imen 
of  an   unmistakable   sessile   cirripede.    which    he    had 
himself  extracted  from  the  chalk  of  llelpum.      And,  h^ 
if  to  make  the  case  aa  strikinjc  as  possible,  this  ses..ile 
cirriiK'de  was  a  (  hthainalus,  a   very  common,   iarjfe, 
and   uhniuitous  ifenus,  of  which  nut  one  specimen  has 
;i.s  yet  been  found  even  in  any  tertiary  stratum.      Hence 
we  n(»w  jKjsitivel     know  that  sessile  cirnpedcs  existed 
during   the    secondary    period  ;    and    the-e    cirrijHnles 
might  have  been  the'progenitors  of  our  many  tertiary 
,ind  existing  species. 

The  cjise  most  frequently  insisted  on  by  j>alieont<il(>- 
iiists  of  the  apparently  sudden  appearance  oi  a  wh(de 
hrroup  of  species,  is  that  of  the  teleostean  fishes,  low 
.iown  in  the  (  halk  period.  'Hiis  group  includes  the 
l.irge  majority  of  existing  species.  Lately,  I'roh'SM.r 
I'urtct  h:is  carrieii  their  existence  one  Hub-^*a^P  further 
back  ;  Htid  some  paheontologist-  believe  that  certain 
much  ul.i.r  h^he.^,  of  which  the  affinities  are  as  yet 
imperfiHtlv  known,  are  rt^illv  t«leostean.  Assuming, 
however,  that  the  whole  of  them  did  apin-ar,  as  Agassiz 
l»elieves,  at  the  commencement  of  the  ch*lk  formation, 
the  fact  would  certainly   be   highly   rem-*rkable  :    but 

T 


If^Jm. 


274 


ON   THE   ORIGIN   OF   SPECIES 


nn 


n 


Mh 


I  cannot  nee  that  it  would  be  an  insuf>eral)l<'  difficulty 
on  my  theory,  uiile.-is  it  could  likewise  l»e  nhown  that 
the  H{>eciet(  of  this  ^roup  a(i{KMn>d  suddenly  and  Himul- 
taueously  throu^hcuit  tne  world  at  this  (tame  period. 
It  in  almoiKt  superHuouH  to  remark  that  hardly  any 
fossil-fish  are  known  from  south  of  the  e<|uator;  and 
l)y  runninjj  throu^rh  IMctet's  I'alif ontology  it  will  be 
Keen  that  very  few  H|)ecieH  are  known  from  several 
formati(»ns  in  Kurope.  Some  few  families  of  fish  now 
have  a  confined  rani^e  ;  the  teleostean  fish  mijrht  for- 
merly have  had  a  similarly  confined  ranpe.  and  after 
bavins'  been  largely  developed  in  some  one  sea,  might 
have  sjtroad  widt-ly.  Nor  have  we  any  ri};ht  to  suppose 
that  the  seas  of  the  world  have  always  l»een  so  freely 
ojHJU  from  Koutli  to  north  as  they  are  at  present.  Even 
at  this  day,  if  the  .Malay  Archipelago  were  converted 
into  land,  the  tropical  [>arts  of  the  Indian  ()c«au  would 
form  a  large  and  perfectly  enclosed  l>asin,  in  which 
any  great  group  of  marine  animals  might  be  multi- 
plied ;  and  here  they  would  remain  confined,  until 
some  of  the  species  became  adapted  to  a  cooler  climate, 
and  were  enabled  to  double  the  southern  capes  ot 
Africa  or  Australia,  and  thus  reach  other  and  distant 
Rea>;. 

From  the.se  and  similar  considerations,  but  chiefiy 
from  our  ignorance  of  the  geology  of  other  countries 
beyoiid  the  confines  of  Euroj>e  and  the  J'nited  States  : 
and  from  the  revolution  in  our  palieontoloyical  idea- 
on  many  points,  which  the  discoveries  of  even  the  last 
dozen  years  have  effected,  it  seems  to  me  to  be  al>out 
as  rash  in  us  to  dogmatise  on  the  succession  of  ort^ini'- 
l>eiiiirs  throu:rhout  the  world,  as  it  would  be  for  a 
naturalist  to  land  for  five  minutes  on  some  one  liarren 
point  in  Australia,  and  then  to  discuss  the  uumiier  and 
range  of  its  productions. 


N!' 


i(i::: 


On  tkf  stuldm  (ip^^-UTdfy^  of  "tow^  of  ALlif'.l  Sticcii'.s 
in  thf  toirejit  known  fossiliferou*  strata. — lliere  is  another 
and  allied  difficulty,  which  is  much  graver.  I  allude 
to  the  manner  in  which  auml>ers  of  species  of  the  same 


4iM 


::**^*?li^^ 


"_i_'Z*ihj 


IMPERFECTION  OF  GKOLOGICAL  RE(  ORD  275 

^roup,  Hud(]pulv  Ri-fPAr  in  the  lowest  known  fossili- 
♦.roiii*  ro<:ks.  Most  of  the  arjrumenti^  which  have  coii- 
finced  me  that  all  the  existinp  Hperies  of  the  wniP 
■rroun  have  desrended  from  one  proirenitor,  apply  with 
nearly  e<jual  force  to  Uie  rarlie^t  known  spc<ie«.  For 
instanre.  I  cannot  doubt  that  all  the  Silurian  triiohite- 
have  dp^i  ended  from  §ome  one  irusUcean,  which  mur-t 
have  lived  htn|r  before  the  Sihirian  aire,  and  which  prob- 
ably differed  greatly  from  any  known  animal.  Nime 
of  the  most  ancient  Silurian  animali,  ah  the  Nautilus, 
l.inc-ula,  etc.,  do  not  differ  much  from  living  •qpecies  ; 
and  it  cannot  on  my  theory  J»e  Hupnosed,  that  these  old 
species  were  the  prosreniU)rs  of  all  the  species  of  tlie 
orders  to  which  they  l^lonjj,  for  tliey  do  not  preaent 
characters  in  any  de'tfree  intermediate  l>etween  them. 
If,  moreover,  thev  had  l)een  the  progenitors  of  tbe>e 
orders,  thev  would  almost  certainly  have  been  lou^r  a*ro 
supplanted'  and  exterminated  by  their  numerous  and 
imp'"i>ve«l  descendant-^. 

Consequently,  if  my  theory  be  true,  it  ia  indisputable 
that  before  the  lowest  Silurian  irtratum  wa*)  deposited, 
lonjf  periods  elap-^ed,  as*  lon<?  as,  or  prolably  far  lonirer 
than,  the  whole  intenal  from  the  Silurian  a^re  to  the 
present  day  ;  and  that  durititr  these  va«t,  yet  quite  un- 
known, periods  of  time,  the  world  swannod  with  liviiiir 
creaturej*. 

)  the  question  why  we  do  not  find  records  of  these 
va.-^t  primordial  f)eriods,  I  can  (rive  no  satisfactorv 
answer.  Several  of  the  most  eminent  geolotri^ts,  with 
Sir  R.  Murchison  at  their  head,  are  convinced  tha» 
we  Bee  in  the  or^ranic  remains  of  the  lowest  Silurian 
stratum  the  dawn  of  life  on  thi.s  planet.  Other  highly 
competent  judges,  as  Lyell  and  the  late  E.  ForlKW, 
dispute  this  conclusion.  ^Ve  should  not  forget  that 
only  a  small  portion  of  the  «.»r]d  is  known  with 
acciiracv.  M.  Barrande  has  lat^-ly  added  another  and 
lower  slaire  to  the  Silurian  system,  al>ouniline  with 
new  and  j>eculiar  species.  Traces  of  life  have  l)een 
dete'te«l  in  the  liongmyud  beds,  Wneath  Harrande  s 
BO-called  prim«.rdial  zone.     ITie  presence  of  phosphatic 


27(1 


ON     I  UK    OKKilN    OK    S1*K(  1F> 


no'liilps  and   liitiimino'is  in.ittor  in  nome  of  the  lowest 

■i/oif  rock-i,  prnli.ilily  iiuliiatfs  the  former  existeiicp  of 

life  at  these  periodH.      lint  the  (lirti<'iilty  «»f  uiulerstaiul- 

nn    tlio   nhseiire   of  v.i-t    pilen   of   fo-.-'iliferoiiH   strata, 

vliich  on  my  theory  no  ilouht  were  somewhere  rirTumii- 

Tte<l    JK'fore    the    SilurKiii    e{>oc}r,    i^    very    t.'r»',it.      If 

;}i('-<-   i!ii»-t   ancient   IhmIs   liad    hrcn   v\  holly  worn   away 

liv  dciiiKlation,  or  ohliterated   hv  m<'Tainorj»hic  art  ion, 

»«!  oiiu'tit   to   tind   only  small    remnants  n{  the   forma- 

Lions  ne\;t  siKveedintf  tlnrii  in  aire,  aj.d  the>.e  oiiirht  to 

Ite  very  irenerally  in  a  metam<>rj)hf)>ed  condition.      Htit 

•ju-   df-criptions  which  wo  now  possess  of  the  Silurian 

ie|>.i-~:t-   o\«!r    immf!i'~e    territories    in    Russia    and    in 

Norlli    America,    do    not    support    the    view,    that    the 

dder  a  formation   is,  tlie  more  it   has  r.lways  surieren 

he  extri'mity  of  deniniation  and  nHtjim(»rpliism. 

I  ho  c^i>o  at  present  must  remain  inexplicahlf  :  aii<l 
nay  l>e  truly  iirtred  as  a  valid  aririifnent  a^f-ainst  the 
viow>i  here  ent»'r!ai!ied.  Co  -how  that  it  may  hereafter 
receive  some  exjilanation,  i  «ill  L'ive  the  followinif 
hypothesis.  I'rom  tlie  nature  of  the  ortranic  remains 
which  do  not  aj)pear  to  have  inhaliited  profound  depths, 
ni  the  several  formations  of  Kiirope  and  of  tiie  I'nited 
>Uites  ;  and  from  the  amount  of  sediment,  miles  iu 
thickness,  of  wliich  the  formations  are  composed,  we 
iMiv  infer  t}i;it  fmni  tirst  to  last  lart^e  i<lanil-  or  tracts 
ot  iand.  whence  the  sediment  wa-  deriNcd,  occurrwl  iti 
the  neirhl>oiirhood  of  the  existirur  continent-  of  Kuro|M> 
and  North  America.  Hut  we  do  m)t  know  what  wa.s 
the  state  of  thin^rs  in  the  inter\als  hetween  the  isiio- 
cessive  formations;  whether  Kiirone  and  tiie  I  iiifed 
."^tates  duriiijf  these  intervals  existed  as  dry  land,  or  a.s 
a  suomarine  surface  near  land,  on  « liich  stMJiment  was 
not  dcjio-ited,  oi-  ii-s  ti.e  hed  of  an  open  .ind  unlathom- 
atd"  -ca 

Lookinir  to  tlie  exi.-tin;.''  cneans.  which  are  thrice  -'i-s 
-'vlensive  as  the  laud,  we  see  them  stuudc<l  with  many 
islands  ;  hut  not  one  oceanic  island  is  a.s  yet  known  to 
aiford  even  a  remnant  of  any  pala»o/oic  or  secondary 
foruiatiou.      Hence  w .•  foav  perhaps  infer,  that  durituf 


ill 


IMI»KKlhCTR)N  OF  (;K(>Uh;ICAL  UK((>IU)  277 


i 


the  paltfo/oio  and  sr.  ond.iry  j.«T;o«ix.  neither  roiitiiu'iit- 
tu.r  cnutiiiental  i«l:ia(l-  exUu-a  when-  our  (x-eauti  n.»» 
pxteiid  ;  for  had  they  existed  there,  palipozoir  and 
H.'eoniUrv  forTiuitii.iis' uould  in  all  |.ruiMih;lity  havf 
l-een  aeruruulati-.!  fmni  -e<l'Mieiit  deriv.'d  fr..-,'  ■\\eiT 
wear  and  tear  ;  and  ^oiiM  have  l»een  at  least  part  ailv 
.;].lMMve(i  l.y  tiie  om  inatioii>  of  level,  whi.h  we  may 
tairU  funcl'ii'ie  rnii>t  have  )iitiT\«'neii  duriinr  these 
enormoiislv  Invj;  periods.  It  I'tu-n  we  may  infer  any- 
th'TiiT  froiii  th.-sti  lattv,  we  nia\  infer  that  wh.-re  our 
ocean-,  now  extend,  ncf.ms  iuve  extended  tn.m  the 
remotest  period  of  whi(  h  we  liav.-  imy  re.ord  :  ami  or. 
the  other  hand,  that  where  .oatinent^  now  e\i-t.  lar-e 
tract.-  oflai-.d  lii-.e  evi^t^-d,  ^iihjerted  m>>  dn'iht  to  irreat 

o^tilialions  ot  level,  since  the  eari.e.st  silunan  \ -od. 

Hi.'  coloured   map  appended   to  my   volume  on   (  or  li 
llees,   l"<i   nie  to  e.iiiclude  that    tlie  trre.it   oceans   are 
rttill  mainlv  areas  o'  suh^ideiice,  the  t:reat  archtpela-oe- 
Ktill  areas  o I   oscillations  ot   level,  unil   the  continent- 
areiu.  of  elevation.      IWit  have  we  any  ri:;lit  to  aK.sumt 
that   thing's   have   thus   remained    from   the   l^'ifiniunc 
of    this   world.'     Our    coniinents    '•eein    to    have    l.een 
formed   i>y  a   prepond«Tan.e,  durintf  many  o«^cillations 
of  level,  of  the  tone  of  elevation:   hut   may   not  the 
areas  of  preponderant  movt-ment  have  ciiaiiL'ed  in  ti..- 
lap-e  oi^  au'e;*.'     At  a  period   immeiisurahly  antecedent 
U>   tiie    Silurian    epoch,    continetits    may    have   e.xi;sted 
where  oceans  are  now  spre^id  out  :  a-id  dear  and  open 
oceans   may   have  existed    where    our    continentn   now 
HtATui.      Nor  shoultl  we  he  justified  in  a-ssumin^  that  if, 
for   inst^mce,  the   hed    of  the    I'aiilic   Ocean    were   now 
converted  into  a  continent,  we  should  there  tind  forma- 
tions older  than  the  silurian  slrala.  supnos.ni;  nuch  to 
have  l>.'en  formerly  deposited  ;  for  it  iin;:ht  well  liappei, 
that  istrata  which"  had   huhsided   some  mjle.s  nearer  tr 
the  tentro  of  the  earth,  and  which   had  heen  pressed 
(»n  hv  an  euormouH  we!;:hi  of  feupenncumhent  water, 
rniirht    have   undert'one  far  more   metamorphic  action 
than  straf.i  which  have  always  remained  nearer  to  'he 
rturlace.      I'he    immense    area-    in    .^ome    jwirt.s    of   ^he 


27  H 


ON   THK    OHKilN   OF   SPECIES 


wnrlil,  for  iiiMtariiu  in  >oiith  Arnerira,  of  liare  metA- 
morpliic  rcK;kn,  '*hich  must  have  \)emu  h«»ate<l  under 
threat  preM<4ure,  have  always*  Hoemwd  in  mo  to  re<{uire 
Honw  spetnal  ex[ilaiiation  ;  ami  vve  may  |>er}iaps  believe 
that  we  see  in  the>e  lari;e  art-A"*,  the  many  lurmatioiiM 
lonjf  anterior  to  the  wilurian  eporh  in  a  completely 
mpfamorphosed  condition. 

'ITie  several  difliculties  here  di««<Misspd,  namely  our 
ii«»t  findiiijf  in  the  Hucresjiive  formations  infinite! v 
numerous  transitional  links  between  the  many  specie^ 
which  now  exist  or  havo  existed  ;  the  sudden  manner 
in  which  whole  j^roups  of  spcc.ies  appear  in  our  Kuro{>ean 
formations  ;  the  almost  entire  absence,  as  at  present 
kncmn,  of  fos>ilifer«uH  formations  beneath  the  Silurian 
'•trata,  are  all  nndoubtedly  of  the  ^Tavest  nature.  We 
see  this  in  llie  plainest  manner  by  the  fact  that  all  the 
mo.«t  eminent  palaHuilolo^isLs,  namely  Cuvier,  .\;:asgiz, 
Itarrande,  Falconer,  K.  Forbes,  etc.,  and  all  our  trre.itetit 
<e<tloifist.s,  as  Lyell,  Murchi.son,  Sedjrwick,  etc.,  have 
unanimously,  often  vehemently,  maintained  the  im- 
mutability of  8{)ecies.  Hut  1  have  rea.Hou  to  believe 
that  one  trreat  authority.  Sir  Charles  Lyell,  from  further 
reflection  entertains  irrave  doubts  on  this  subject.  I 
feel  how  rasti  it  is  to  ditfer  from  these  authorities,  tu 
whom,  with  others,  we  owe  all  our  knowledge.  Thosjs 
who  think  the  natural  treolojrical  record  in  any  decree 
pprti'c',,  and  wlio  do  not  attach  much  weight  to  the 
facts  and  artruments  of  other  kinds  jfiven  in  this 
volume,  will  undoubtedly  at  once  reject  my  theory, 
i'or  my  part,  following  out  Lyeii's  metaphor,  1  look  at 
the  natural  treoloarical  record,  as  a  history  of  the  world 
imperfectly  kept,  and  written  in  a  chaniriii;,'  dialect  ; 
of  this  history  we  posse-sd  the  last  volunte  alone,  relat- 
ing: only  to  two  or  three  countries.  Of  this  volume, 
,)nly  here  and  there  a  short  chapter  has  been  pre8er\ed  ; 
ind  of  each  itaire,  only  here  and  there  a  few  liues. 
I'^ch  word  of  the  slowly-chaufj^iii^  languag'e,  in  which 
tlie  history  is  supposed  to  be  written,  l)ei!Hf  more  or 
le--  different  in  tue  in'e.-rupted  suicH^Nsion  of  cliapters, 


IMFKRFE(TI()N  OF  (JKOUHWC  AL  KK(ORr)  279 

maN  r.'pri-sent  the  ai.j.arontly  abruptly  changeti  funrm 
of  litV,  entoni»K«(l  in  o.ir  roti^ntive.  but  widely 
•fiMirated,  formatioiH.  <  ►n  this  view,  tlu'  diffiriiltiM 
alinve  dinriiwd  .iro  trreatly  dinnninhod,  or  even 
diB<t|;{>ear. 


^:^'^ 


l^^M^. 


(  [JAI'J  KK    X 


I  I  f  K 


i,f"'l  (m.i.aI      km  (  »>.«lu.N     Ol.     ii,(  .A.MC    li, .!>«(» 


<l-tf.'nt  r,it«-»  ..f  ,1, 1-,.-    .>iM-.i,-.  ,.n.  «■  l.„t  .)..  II. .1  Tf»n'-iir 
«.r<ii|«  .f  «[»■.  !.•«  fnll.w  the  name  ^.  m-ral  rul.-i  in  tJidr  :.|i{H^ar 
ati.  ,■  aii.l  .I11..1;  i..-.ir.iii(e  an  >|.i  mi  wif  »!«■.!.«    un    Kitin.ii  ,ii- 
On    i.itiiiilt.ine..ii»   .liiiiuft-*   (11    lh«-   f.,niii   c,f   hfr    Uir   'lu'liMiit  U  r 
w.  fM     (i|,   the  «tt!!i(tleii  ..f  rxtliut  i-jx-olet  t  i  r%ih  •.1!,»t  ind   [.. 
luii  «  SI).-.  ir»     iiii  Uic  Hint.-  ..f  ,1.  wl..i,rtiH!,t  ..f  aii.'lriil  f.,niui 
Oi,   •»,,.  iii,-,r^.M  .11   c.f  tho  K.'iiie   tNjMB  witJilu   Ui«-   Vf  .■   Brea.- 
Siiii;iiiary  of  i)ri.«-«.|iii(;  aihl  iii.t.,iit  .  hapt.  r». 

I-Ki  us  iinw  >.n  uhftluT  tii»>  several  Jact-  .lu-l  niies 
rfl.itiiitf  t(i  tin-  tri'oli.j^;ciil  Micct'^hioH  of  oiLMiiio  lmiri<8, 
l».'tt.T  ac.oi-fl  with  the  roninmn  view  of  the  irimiuta- 
l>ilil>c)f  specie*,  or  with  I  hat  of  their  slow  ami  ^rradua! 
riio.lifu-alitiii,  throutrh  (iexeut  aii.l  natural  seleetion. 

Ne\\  >|,e.  jes  have  am>eare<i  very  slowly.  (>!ie  atu-r 
another,  i.-.th  on  the  l.ind  and  m  tlie  w.-iters.  I.yell 
hu-.  >ho\\ii  tii.it  il  i»  li.irdiy  jM.^sihle  to  re>ist  theevidetjco 
on  tins  head  in  the  ease  or  the  several  tertiary  statres  ; 
and  every  year  U-nds  to  till  up  the  hi  ink>' between' 
thetii.  and  to  make  the  pereent.iire  system  of  lost  and 
new  forms  more  ^rnulual.  In  siune  of  the  most  recent 
UmIs,  llMdiirh  niulouhtedly  of  hi^rh  antiijuity  if  measured 
by  \e.irs,  only  one  or  two  spi,  ies  are  lost  forms,  an-! 
only  one  or  two  are  new  form-,,  having  here  aj>|K'ared 
for  the  first  time,  either  locally,  or,  aH  far  as  we  kno», 
on  tilt-  ra.f  ui  tiie  earth.  if  we  may  trust  tiio  oliserva- 
tion«  of  Thilinjd  in  .'^icily,  the  suices.sive  changes  m 
the  marine  inhihitants  of  that  island  have  h* 

'2iM 


'een  many 


>A^.  J^glfaMT /£f  'VH^Sa^' 


«.K»»!.(h;I(  AL  Sl(  ( I-SMON 


JHI 


Hill  riii»t  trriKtii.il.  nn"  -•■.omljiry  format inii«  .iri«  mor*- 
hrokfii  ;  Itiit,  a«  Urnrin  lias  roniarkrd,  ru- thrr  thr 
ai>|.".ira!irp  n«»r  (lis;nij.«'araiu'f  of  tlipir  many  im"  ••x- 
♦  iii.t  s|„Mitw  lias  l^-t-u  Biniiiltntu'oii-*  iii  »>a«"h  wj'iirati- 
frtrinaiKiii. 

>}>««(i»'s    of   (iiHi'r«'nt    ir»'ii«*ni    and    rla.-o««'s     liavc    ni.t 
iii.iiiir»M|  at  the  siiriu-  rat*-,  or  in   llio  Hiinif  «l»'»rr«'r        In 
the  nlilf^t  tiTtiary  IhmU  a  f«'v*    livini:  nhcllH  may  -till   U' 
n»tin.l    HI    till'    mi'dst    of  a   mi]ltitu<le  ot  extinrt    I.Trn* 
K.i!i-..n».r  hi-*  irwou  a  '■trikiiij:  in-tanir  ut  a  simil.ir  ;t«t. 
Ill  .III  fxistinif  iriMo.liU'  a-si..iatr.l  with   many  »traiiu'»' 
and   lost   niammaU  ;<iid  n'l.'iU's  in  the   su»v-Ilim.tlayati 
d.-;..wil.H.        Hie  ^llurian    l.iin'ula  dirT«'rs  but  littU-  iron' 
U.«'  livinir  HiHH-ipx  of  thic  lf•Mlu^  ;   v*h»Tp»H   inont  of  tl  e 
ntl)»'r  Silurian   Mollii-«»»  and  all  the  (  nisfir«'an«»  havt- 
»  hMijft'd  ^'r«Mtly.     Tne  priHliution-  of  th««  land  mtiu  to 
tliainrc  ..t  a  <iuii-ker  rat«  than  thos«  ofthe.-ra,  ntwhic  it 
a  strikiiii:  iiKtan.c  ha.n  lately  U««»m  ohservt'd  in  Swit/vr- 
luiid       'I'liero  i-i  -'inu>  Ta-oii  to  helievp  that  orKain-m-*. 
con!.idered   hiu'h   in  th»^  »«-a1p  of  nature,  rhaiiKe   morr 
.|iiii-kly  than  tho«#  that  are  low  :   thoiijrh  there  are  ei- 
ceptmns  to  thi-*  rule.        I'lie  amount  of  oriranic  chaiiife, 
&A    I'ittet   has  remarke^l.  doe«  not  Htrictly   corre-jH.ud 
with   the   surre-ixjon   of  our   ir'^olotrical  formations  ;  ho 
that    Wtweeii    »-a.  h    tv»o    .(.n-eiutive     formation-*,     the 
forms  of  lite  have  seldom  chanired  in  exactly  the  same 
detfree.      Vet   if  we  compare  ariy  I'ut  the  most,  clos.dv 
relate.!  formatioiiii,  all  llie -..enes  will  be  found  to  ha\e 
undertrone  some  chantre.     When  a  sj>ecie8  has  once  d'H- 
apwared  from  the  face  of  the  earth,  we  have  reason  to 
l)elie\e  that  the  same  identical  form  never  reappear*. 
I  he  stronirest  apparent  exception  to  this  latter  rule,  is 
that  of  the  sJvcaHed  "colonies"  of  M.  Barrande,  which 
intrude  for  a  period  in  the  midst  of  an  older  formation 
and  then  allow  the  pre-existiii<f  fauna  to  reapjM'ar  :  but 
I. veil's  explanntion,  nami-ly,  that  it  \h  a  case  of  tciiif)0 
niry  mijfration  from   a  distinct  treotrraphical  province. 
t»et'it>»  to  nie  satistictory. 

Ti  cse  several  factH  accord   well  with  my  theory.       1 
believe  in  no  tixed  law  .if  rlevelopment,  cau-iins:  all  the 


282 


ON  THE   OKiGIN   OK    SI'Ef  IKS 


W! 


Ill' 
it' 


inlialiit.ints  of  i  country  to  chaniro  abruptly,  or  simul- 
taripftusly,  or  to  an  equal  tlevrrcf.  'J'lie  process  otino'li- 
hcation  must  he  extremely  ^low.  ITie  variahilitv  of 
t-ach  species  is  quite  iiuiepeiKkMif  of  that  of  all  others. 
H\  hether  wtirh  variability  he  taken  advantage  of  by 
natural  selection,  and  whether  tlie  variations  he  accu- 
mulated to  a  ;;reater  or  les>er  amount,  thus  causin^f  d 
.Tciter  or  It^sser  amount  of  modification  in  the  varyiut' 
species,  depends  on  many  complex  coiitinjrencies, — on 
tiie  variability  lieinjf  of  a  beneficial  nature,  ou  the 
power  of  inUircrossinj;,  on  the  rate  of  breeding?,  on  the 
slowly  chan^injf  physical  conditions  of  the  country, 
and  more  especially  on  the  nature  of  the  other 
inhai)itant3  with  which  the  varyinj;  species  comes  into 
competition.  Hence  it  is  by  no  means  surprising-  that 
one  >{iecies  should  retain  the  same  identical  form  much 
loiurer  tlan  others  ;  or,  if  chansriiiir.  that  it  should 
cliaii:re  less.  ^V'e  see  the  same  fact  in  ireoirraphical 
distribution;  for  instance,  in  the  land-.^ie''  and 
coleopterous  insects  of  Madeira  having:  come  to  ditTer 
considerably  from  their  nearest  allies  on  the  continent 
of  Kuro(>e,  whereas  the  marine  shells  and  birds  have 
remained  unaltered.  We  can  perhaps  understand  the 
apparently  (juicker  rate  of  chancre  in  terrestrial  and 
II  more  hijjfily  or^ranised  productions  compared  with 
marine  and  lower  productions,  by  the  more  complex 
relations  of  the  hiirhcr  beintjs  to  their  orjfanio  and  in- 
ortranic  conditions  of  lite,  as  explained  in  a  former 
chajiter.  When  many  of  the  inhabitants  of  a  country 
iiave  become  modified  and  improved,  we  can  under- 
ftiind,  on  the  principle  of  competition,  and  on  that  of  the 
many  all-imj-irtant  relations  of  orjranism  to  organism, 
♦  hat  aiiv  form  which  does  not  become  in  some  dejfree 
TtMiditiod  and  improved.  \r\\\  be  lialde  to  be  exter- 
minated. Hence  we  can  see  why  all  the  sjKscies  in 
the  same  reiriou  do  at  last,  if  we  look  to  wide  enouirh 
inter  vals  of  tune,  l>ecoine  nuiditit  d  ;  f(»r  those  which  do 
not  chanfje  wiU  become  evtiiut. 

In  nieml  »'r-.  of  the  s;ime  L-Luni  the  nveraere  amount  of 
chjuire,  di  rui;^'    lon^  and  equal   tn'riods   of  linn?,  may, 


GE()U>r.irAL  SfTCKSMON 


2X\S 


(^rha,.s  hp  rif-arlv  ti.e  -aine  ;  but  as  the  r>rr-nnuilation 
ui  l..n^-eiidurinL''  (..-Mliterous*  ionnatioii>  (1.'J>«*ii.1h  oil 
^reat  masses  of  sediment  haviiitr  Wen  deposited  on 
^reas  wlii!.-t  sulisidiriif,  our  formations  huve  been  almost 
.,f*es>arilv  afcunuilated  at  wide  and  irret:"larly  uiter- 
mittcnt  iiitrrvaN  ;  conse<|i]ently  the  amount  ot  orjfanir 
.•hai.tre  exhibited  bv  the  tos.MU  emlu'ddrd  in  n)n>ecutive 
tormations  is  not  equal.  Kach  formaUon,  on  thw  vi«w, 
does  not  mark  a  new  and  complete  act  of  creation,  but 
.iiilv  an  oci-a.-ioiial  srene,  taken  r.ltnost  at  h.ward,  in  a 
hio^flv  chaniriniT  drama. 

W  V  can  clearlv  understand  why   i  species  when  one- 
lost  should  never  reappear,  even   if  Lne  verv  s.ime  con 
litious  ©f  life,  or-raMc   and    iimrtranic,  should  recur 
For    tiiouych    the   otf-prin^    of"   one   speties    mitrht    1«- 
ndapted    (and   no  doubt  this  has  occurred  in  inuumer- 
it.ie  lustanres)  to  fill  t!ie  e::act  pla.o  of  another  specie-s 
11  the  economy  of  nature,  and   thus   supplant  it;   ye', 
the  two   forms— the  ohl   and  the  new— would   not  be 
identically  the  s.iine  ;  for  l)Oth  would  almost  certainlv 
inherit  ditTereut   characters    from    their    distinct    pro 
t'enitor.s.       For   insUnce,   it    is    just    possible,    if  our 
!ant:iil-pii:eons  were  all  destroyed,  that  fanciers,   by 
^triviti^  duriotf  lotiir  aijes  for  the  same  object,  niiifbt 
make  a  new  breed  hardly  di.-tinguishable  from  our  pre- 
sent fantiil  ;  but  if  the  \areut  /ock-piffeon  were  also 
destroy.'"!,    and    in    nature   we    have  every    reasoa    to 
I.elieve  that  the  parent- form  will    generally   be  suj>- 
planted  and  exterminated  by  its  improved  otfsprinjj,  it 
is  quite   incredible   tliat  a  fan  tail,  identical  with   the 
exi^tinp  breed,  could  be  raised  from  any  other  speciea 
of  pigeon,  or  even  from  the  other  well-e.>.tablished  races 
of  the  domestic  pijfeon,  for  the  newly-forrned  fantail 
would  !«  almost  sure  to  inherit  from  its  new  progenitor 
some  slijjht  characteristic  ditfereiucs. 

(iroups  of  sj)ecie^<,  that  is,  (reneraaud  families,  follow 

the  same  ireneral    rules  in  their  api>earance  and   di*- 

apiK-arance  as  do  >iiii:le  si)e<!ies,  ohaniCi"K  more  or  ie>« 

luickly.  a-id  in  a  ureater  or  les.cer  dejrree.       A  ^rroup 

due»<  r.>t  rf-»ppea-  after  it  hau  once  dixii-peared  ;  or  it« 


^»  1 


ON  THK   OKICIN    OK   8rh(  IKS 


1*1 


|i 

III 

i 

I' 

is 

S-^r 

f?  •!«      i 

.T 

1: 

exiH'.fticp,  aH  utii^'  as  it  lasts,  is  rontiiiuous.  I  .-.i.-. 
iware  tliat  thort'  are  Mjine  a[>[iarfcnt  exceptions  to  thi? 
rule,  l)iU  the  exceptittiis  are  siirprisintrlv  few,  so  lew 
tliat  K.  Ftirl»es,  I'lctj^t.  and  W DodwarW  ^houtrh  all 
sfroiitrly  opitosed  to  surli  views  as  1  niaiuuiin)  admit  itn 
tr'itli  ;  .'ud  the  rule  strictly  ac«'ord>  with  my  theorv. 
lor  as  all  (lie  species  of  the  same  frr<iiip  have  desct'udeii 
from  sidiH-  I. lie  sjM'cies,  it  is  cicar  thu  as  lonu  as  any 
-;>»'<H's  ut  iiie  >froiip  have  appeared  in  the  lon^  suc- 
I  e--  1)11  of  atre>,  so  Ion:;  must  its  inemtMTs  have  con- 
tiiitioiisly  existed,  in  order  to  liave  {reuerated  eitlier  new 
lud  inodituMi  or  the  same  (dd  antl  unmodilied  furmH. 
^p«'<  les  of  the  trenus  l.inyula,  tor  iiisLiince,  must  have 
<-ontiiiii(nisly  existed  hy  an  unhroken  succession  ot 
uerierations,  trmri  the  lowe.st  Silurian  stratum  tx)  the 
present  d;i\ . 

\\'«'  havt*  seen  m  lli.'  last  chapter  tliat  tiie  species  of 
a  irroup  Hometime,s  falsely  apjH'^r  to  have  come  in 
aiiriipti'y  ;  an.i  1  liave  attempted  to  jfive  an  explanation 
of  this  tact,  whicii  if  true  would  have  heen  t.iial  to  mv 
views.  Hut  sui-h  cases  are  certainly  excej>tional  ;  the 
g-eneral  rule  heinfr  ajrradual  increase  ni  inimU'r,  till  the 
ifroup  readies  it«  maximum,  and  then,  s<M)ner  or  later, 
it  fzradually  decrea.ses.  If  the  iiumher  of  the  species  of 
a  tienus,  or  tli»  uumher  of  the  frenera  of  a  family,  he 
represented  by  a  vertical  line  of  varying  thicknes:*, 
cros^iiiiT  the  successive  ffeolotrical  formations  in  which 
the  species  are  found,  the  line  will  sometimes  falsi>lvap 
I>ear  to  lie^rin  at  its  lower  end,  not  in  a  sharp  point,  but 
aliruptly  ;  it  then  ^rrulualh  thickens  ups*ards,  some- 
times keepiiiff  for  a  space  of  et^ual  thickness,  and 
■iltimately  thins  out  in  the  upjMir  In'd-,  marking  the 
decrease  and  final  extinction  of  the  species.  This 
jfradual  increase  in  numl-er  of  the  tpecies  of  a  group  is 
striitly  conformable  with  mv  theory  ",  as  the  species  nt 
the  same  tj-enus,  and  the  genera  of  the  siime  family,  can 
increase  onlv  slowlv  and  nni.^^ressivelv  \  for  tlie  i)rii<e»is 
of  moditication  and  the  production  of  a  numl)er  of 
allied  tomis  must  be  clow  and  trradual,  -  one  species 
irivin^'    rise  first  to  two  «tr  three  varieties,  these   bpirig 


m 


GEOUXJK  AL   Sl'C  (  KSSION 


2«A 


kIowIv  ronvert»'(l  iritu  sp«M-ies,  which  in  their  tiirTi  nn>- 
(iure  Vy  equally  slow  st»>i>s  nther  «*pe<"ie«t,  and  soon,  like 
tlie  hninrhiii'JT  of  a  (rrt-it  tree  from  .1  single  «teni,  till 
tf.f  tjrdiip  hecoiiia**  l.irjfe. 

nn    Krnuitxir, i.-W  *i   li;i\e  a^  yet  <i>oker.   o;i!y    itifi- 
'ieiitally  of'  tiie  (li>aj>p«Mraiire  of"  sjxvio  and  "t"  trroujH 
of  siiccif-i.      <  >n  the  theory  of  iiaturnl  '^election  the  ex- 
tiiKtion  of  oltl  forms  and  the  [»r<Mliiction  of  new  atiil  im- 
proved forms  are  iiitiin.iN-ly  loniu'fted  toirether        Ihe 
ohl   notion  of  all   the   inhahitants  of  the  earth  haviiur 
l>een  swept  awav  at  successive  i>eriod>*  hy  catastrophes, 
is  very  general  I  v  iriven  up,  even  hy  tiiosc  jfeoiosfij*tM,  as 
Klie  de    lU'aumi)nt.  Miirclii-son,  IJnmnde,  etr.,  whose 
t'C'iieral  views  would    naturally  lead   them    to  this  con- 
clusion.     <  )m   the  contrary,    we   have  every    rcisoii    to 
'•tlitnc,  froHi  th»^  study  of  flie  tertiary  forniatons,  that 
species  ,iiid  irroups  of  spf.  ics  aradually  dis;ip].t>ar,  on*' 
I'ter  another,  first   from  one  sp-ot,  then  from  .mother. 
aid  finallv  from  the  world.        lioth  single  sjwt  us  and 
whole  irroujM  of  «pecies  last  for  very  unequal  periods  ; 
some  trmujH.  as  we  have  seen,  havinjr  endured  from  the 
earlie-t  known  dawn  of  life  to  the  present  d.iy  ;  tMime 
haviii:;  dis;»pp«'ared    lK?fore  the  dose  of  the  pal.eozoic 
peri<»<l.      No  fixed  lav*'  seems  to  determine  the  lernftl)  oi 
rune  durinir  wlii"h   any    suiL^le  species   or   any   sinirle 
:rtnus    endures.        I  here    is     rea-son     to    l>clieve    that 
the  cotuplete  extinction  of  the   species  of  a   trroup   is 
treiu'rallv  a  slower  pro<ess    han  their  producti<»n  :  it  the 
appearance  and  disappt^arance  of  h  jrroup  of  speiies  U- 
rejiresented,  as   hefV>re.   hv   a   '-ertical   line   of  varvinir 
thici<uess,  the  line  is  found  to  taper  more  trrad. ally  at 
its  upper  end,  wiiich  marks  the  pr<>irress  of  extermina- 
tion,   than    at    its    hiwer    end,   which    marks    the    first 
appearance  and  increase  in  iiumhers  of  the  species.     In 
suine  case-,  however,  the  extermination  of  whole  j;'rO(i{>s 
of  heiutrs,  as   of  ammonites   towards   the   close  of  tf;e 
secondarv  period,  iias  t^'en  wondertuiiy  suiiden. 

riie    whole  suhiect    of  the  extinction   of  species   ha.t 
'<ee?i  involved  in  the  mo<*t   irratuitous  oiv«terv.       >ome 


ZWi 


O.N    UIK   OKKJIN    OF    ."^I'KCIfcS 


author"  li.ivp  pvi-n  -uppo'^pii  tlmt  ;»^  'lio  imlividual  lian  + 
(iofiiiite  Ifii^rtli  ol  life,  hh  liave  Kji»vi#>s  a  dt'rtiiite  dura 
tioii.  No  ono  1  think  can  li;ive  marvelled  more  at  tl;p 
extinction  of  sporie",  tlian  I  liavedone.  W  hen  I  found 
in  I>a  Plata  the  toolh  of  a  liorst*  embedded  witli  the 
remains  of  Mastodon,  Me^atnerium,  Toxodon,  and 
other  extini:t  mon^ters,  which  all  coexisted  with  stil' 
livinj;  shells  at  a  very  late  treoloffical  p^'riod.  !  wa*  filled 
witli  astonishment  ;  for  seeini:  that  the  horso,  since  its 
intro<lu(tion  by  the  Spaniards  into  South  America,  has 
run  wild  over  the  whole  country  and  has  increased  in 
nMmi>er«  at  an  unparalleled  rate,  I  nsked  myself  what 
coiilil  M)  recently  have  exterminated  tin*  former  horse 
under  conditions  of  life  apparently  so  favourable.  But 
ho'v  utterly  groundless  was  my  astonishment  I  Pro- 
f",.^..(,r  ( >weii  soon  perceived  that  the  tooth,  though  >*n 
like  that  of  the  existing  horse,  belonged  to  an  extinct 
species.  Had  this  horse  been  still  livintr,  but  in  some 
lieirree  ran-,  no  naturalist  would  have  felt  the  least  sur- 
prise at  its  rarity  ;  for  rarity  is  the  attribute  of  a  vast 
number  of  species  of  all  classes,  in  all  countries.  If 
we  ask  ourselves  why  tliis  or  that  sT)ecie.s  is  rare,  we 
answer  tliat  somethinjf  is  unfavouraide  in  its  conditions 
of  life  ;  but  what  that  some'liine;'  is,  we  can  hardly  ever 
tell.  On  the  supposition  of  the  fossil  horse  still  exi.st- 
in:r  as  a  rare  species,  we  miirht  have  felt  certain  from 
the  analoiry  of  all  other  mninnials,  even  of  the  slow- 
iireedini;  elephant,  and  from  the  history  of  the  natural- 
isation of  the  domestic  horse  in  South  America,  that 
under  more  favourable  conditions  it  would  in  a  very  few 
years  have  stocked  the  whole  continent.  Hut  we  could 
not  liave  told  what  the  unfavourable  conditions  wi-re 
whitli  checked  its  increase,  whether  s(»me  one  or  several 
coiitinjrencies,  and  at  what  period  of  the  hor.se's  life, 
and  in  what  deyree,  they  severally  acted.  If  the 
<i»nditioiis  had  gone  on,  however  slowly,  becominir 
less  and  less  favourable,  we  a.ssuredlv  should  not  ha\(' 
perceived  the  fact,  yettlie  fossil  horse  would  certainly 
iiave  Itecome  rarer  and  rarer,  and  tinally  extinct  : — it^" 
place  i)eins  sci/ed  ou  by  some  more  successfai  competitor. 


m^y. 


GEOLfHilCAL  SL'CCEisMON 


Ml 


It  i-  most  -liffictilt  always  to  rem»'nil»er  tliat  th« 
increase  of  every  liviriir  Uoitif?  i«  constantly  heituf 
checked  by  unperceived  injurious  a^'eiu-iej*  ;  and  that 
these  same  unperieived  a^rencies  are  amply  sufficient  to 
i-Auwe  rarity,  and  liually  extinction.  U  e  see  in  many 
rases  in  the  more  recent  tertiary  formations,  that  rarity 
precedes  extinction  ;  and  we  know  tli;it  this  has  heen 
the  projrress  of  events  with  those  animals  wh^ch  have 
heen  exterminat.'d.  either  locally  or  wholly,  through 
man's  agency.  I  may  repeat  what  1  published  in  184.', 
namely,  that  to  admit  that  specits  »renerally  l»ecome 
rare  before  they  become  extinct— to  feel  no  surprise  at 
the  rarity  of  a  s|)ecies,  and  yet  to  marvel  greatly  when 
it  ceases*  to  exiit,  iti  much  tlie  same  as  to  admit  that 
siokuass  in  the  individual  is  the  forerunner  of  death  — 
to  feel  no  surprise  at  sickness,  but  when  the  fiick  man 
dies,  U)  wonder  and  to  suspect  that  he  died  by  some 
unknown  deed  of  violence. 

Hie  theory  of  natural  selection  is  jrnninde<l  on  the 
l»elief  that  each  new  variety,  and  ultimately  each  new 
species,  is  produced  and  maintained  by  havinp  ^ome 
advantage  over  those  with  which  it  comes  into  com- 
petition ;  and  the  consecjuent  extinction  of  les,s-favoured 
forms  almost  iiu'vit;ii>ly  follows.  It  is  the  s,ime  wi'h 
our  domf>lic  productions  :  wlien  a  new  and  slijfhtiy 
imj)roved  variety  has  l>een  raised,  it  at  first  supplants 
the  le>s  imi)roved  varieties  in  the  same  neiirlibourhood  ; 
when  mucii  improved  it  is  tran^^ported  far  an<l  newr, 
like  our  sliort-iiorn  cattle,  and  takes  the  place  of  other 
breeds  in  other  i^untries.  Thus  the  appearance  of  new 
forms  and  the  disappearatu:e  of  old  forms,  both  natiir;il 
and  artificial,  are  bound  together.  In  cerUiiii  Jiourishiinr 
jfnmps,  the  numlier  of  new  specific  forms  which  i:ave 
l>een  produced  within  a  :riveu  time  is  probably  trreater 
tliau  that  of  the  old  specific  forms  which  have  l>een  ex- 
terminated ;  but  we  know  that  the  number  of  species  has 
not  jrone  on  indefinitely  increasing,  at  least  durinar  th" 
later  )feo!ofjii-ai  periods,  so  that  looking;  to  later  times  we 
may  l>elieve  that  the  production  of  new  forms  has  caused 
the  extinction  ofa^'out  tiiC  same  numl>er  of  old  forms. 


"«%*<A'aG»«C 


:8« 


ON    THK    ORIGIN    OK    S|'K(  IKS 


riie  competition  will  trctierally  !'♦•  ninst  sever-'.  ;i. 
foriii»*rly  exiilained  and  illii-lr;it»'(|  l>y  oxaTn|il«»>i,  lietwoen 
t.lu'  forms  which  are  i.io<t  like  «'a<h  other  ui  ail  re-jpectn. 
Ifenc«^  the  improved  and  niodiricd  des(-tii(iaiib>  of  a 
sj)»M  jpi  will  treiitTally  <'ause  th»-  evtermiiiition  of  the 
j'.irerit-specit'-'  :  ami  it  many  new  forms  have  U»eii 
Jevt  Inped  from  any  one  species,  the  nearest  alliex  of 
ti>at  ^|•ecie'^,  i.f.  the  sp«M'ies  of  the  'aino  sreniis,  will  U- 
the  n-.ost  lial>le  to  extt-rmination.  Ihus.  a>  !  l>eli»>ve.  a 
Munilitr  of  new  species  dt^^iended  from  one  sp«'<ii's,  tint 
is  a  new  ireniis,  c<mieH  to  supplant  an  old  peruis,  helont;- 
Hitf  to  the  same  family.  Until  nvi-t  often  have  hapji'-iied 
tliat  a  new  species  l)eloniriiijf  to  some  one  cr'>iij>  "''''  have 
^.■i/ed  on  the  place  occuiiied  hy  a  spfcie**  l»eIontrHijr  to 
I  distinct  irroiiT>.  ami  thus  caused  its  extermiiia'ion  ; 
and  if  iiianv  allied  forms  he  develoj)ed  from  the  sin-ces^ 
fill  intruder,  many  will  have  to  yield  tlieir  places  ;  and 
it  will  treneraljv  he  alliid  forms,  wliich  will  suffer 
troT'i  some  niln'rited  inferiority  in  connnon.  liiit 
whether  it  he  species  heloniring:  to  tiie  same  or  to  a 
di-tiiict  class,  which  yield  tlieir  places  to  other  spe«'ies 
wtiicli  have  heen  mnditied  and  impro\ed,  a  few  of  the 
-nfferers  may  often  long^  he  nreserved,  from  heint 
fitted  to  vonie  peculiar  line  of  life,  or  from  inliaintin^ 
some  distant  ami  isolated  station,  wliere  they  have 
escaped  severe  competition.  For  instance,  a  sinijle 
species  of  rriii-onia,  a  ^reat  ireiMJ<<  of  shells  in  the 
secon'larv  formations,  survives  in  the  Australian  se;is  ; 
■ind  a  few  memhers  of  the  groat  anrl  almo-t  extinct 
LTOiip  of  (ianoid  ti.-hes  still  inhahit  our  fre-h  wafers. 
I"!  TPiore  the  utter  e.xtinction  of  a  irnuiji  is  trene-ally, 
as  >v-,   )ia\e  seen,  a  slower  process  than  its  produitioti. 

\'»  ith  respect  to  the  apparently  sudden  extermina'ion 
•  f  whole  families  or  ord«'rs,  as  of 'I'riiohites  at  the  close 
.>f  the  paheo/uic  period  and  of  .\mmonites  at  the  close 
of  the  secondary  period,  we  nuist  rememher  what  has 
Seen  alrea'iv  ^aid  ')u  the  nr<ih-'\hle  widt»  ii'ti"vais  of  time 
hetween  our  ccnsecutivc  formations  ;  anu  ui  these  inter 
vals  there  may  have  Keen  mucli  slow  extermination. 
Mor''ii,er,  vhen  hy  Hudden  immigration  or  hy  unusually 


(;e()Ukjical  succession 


Z3i) 


r.tj'  H  (l«'Vf'lopmcnt,  many  ':T>«*<"ip«  of  a  in-w  trrou})  have 
Ui  'U  p<»-.}*c>sion  of  a  new  urea,  they  will  have  pxter- 
niiiuti'ii  in  a  corresivoTNliiitrly  rapifl  iiiaiiiier  tn.iiiv  of  the 
old  inlial>iL;nits  ;  ami  the  forms  which  thii<  yiel<l  their 
j>lace^>!  '.vill  romnuiiily  he  aUied,  for  they  will  partake  i>f 
Bome  iiiteriority  in  common. 

Ihus,  as  it  M'enis  to  me,  the  manner  in  which  hinjfle 
i«|M'cie><  and  whole  jfroiips  of  s[»e4"ies  l>ecome  extinct, 
acconlx  well  with  the  theory  of  natural  Hclection.  \\  e 
net'il  not  marvel  at  extinction  ;  if  we  must  marvel,  let 
it  he  at  our  presumption  in  imairinin^  for  a  moment 
that  we  iiiulerstaiid  the  many  c«m>j»lex  contin^'-encies, 
on  whii-li  the  existeme  of  each  sjiecies  de|>end«.  If  we 
for>:et  for  an  instant,  that  each  sjiecies  tends  to  incrcHHe 
inordinately.  an<i  that  «ome  check  is  always  in  action, 
yet  s«  Idiiin  perceived  hy  us,  the  whole  economy  of 
nature  will  Ikj  utterly  ohscured.  Whenever  we  can 
precisely  siiy  why  thi«  «i)ecies  is  more  ahuudant  in  in- 
dividuals than  that ;  w)iy  this  species  and  not  another 
can  he  naturalised  in  a  ^ven  country  ;  then,  and  tut 
till  then,  wv  may  justly  t'eel  surpri>ed  why  we  cannot 
account  for  the  extinction  of  this  particular  species  or 
tfroup  of  speci«'s. 


''n  the  f'oniui  of  Lih  rfuivijini/  ti/riuu<t  tnrnu/taurou«/t/ 
througfmiit  the  WiirM. — Scarcely  any  pal*eontolo>;ic,i| 
discovery  is  more  strikinj;  tlian  the  fact,  that  the  forms 
ot  lite  chanire  almost  simultanei)usly  throujrhout  tli" 
uorld.  Thus  our  European  (  halk  formation  can  he 
recognised  in  many  distant  parts  tti  the  world,  und«'r 
the  nu»sl  different  climutes,  where  not  a  frairment  of  tlie 
mineral  chalk  it.-elf  can  he  found  ;  namely,  in  North 
America,  in  ecjuatorial  S«)Uth  America,  in  Tierra  del 
Fueifo,at  tlie  (  aj)eof  (Jood  Hope,  and  in  the  peninsula 
of  India.  Tor  at  these  distant  pointji,  the  or^rani*!  re- 
mains in  certain  he<ls  present  an  unmistakahle  detrree 
of  resemhlance  to  those  of  the  Chalk.  It  in  not  that 
the  sanu«  species  are  met  with  ;  for  in  8ome  cAhe«  not 
one  species  is  identically  the  same,  hut  they  lM-U»ne"  t<» 
the  same  families,  (genera,  and  sections  of  penera,  and 

I' 


2U0 


ON   TIIK   ORKilN    OF   t>l»E(  IF> 


?     U 


M 

i  ■£.■- 

II 


.1 

If 


■ometimcs  are  Himilarly  i-harat-toriM'tl  in  nurh  trifling 
points  as  nu're  sii[»«'rtifial  sculjitiir**.  Moroover  other 
forms,  which  are  not  foumi  in  tlu*  (  iialk  of  Kiir<i|)e,  but 
wliirh  i)»<ur  in  thi*  tomiationH  i-ithtT  alxive  or  h«'h»w,  ar« 
Himilarly  absent  at  these  <li-tant  points  of  the  w(»rlfi.  In 
the  several  su(('e>si\e  palieo/.oic  formations  of  llussia, 
Western  Kiiro|»e  and  Nnrth  Arr.erira,  a  similar  parallel- 
ism in  the  fnrm>  of  life  ha^  been  observed  by  several 
authors:  so  it  is,  aicordiii:.'  to  Lyell,  with  the  several 
Kiiropean  and  North  Anieriran  tertiary  depovit.s.  Kven 
if  the  tew  to>-sil  species  whicli  are  conuiKiu  ti>  the  ( lid 
and  New  \\  orlils  be  i\ept  wholly  out  of  view,  the  fcT^'Jieral 
j»arallfli-in  in  the  siiccessiv4«  forms  of  life,  mi  the  sta^ei 
of  the  wiilely  separated  pala-ozoio  and  tertiary  p''rio<ls, 
would  still  bf  mainlest,  and  the  scverrd  formations 
rould  be  easily  correlated. 

These  observations,  however,  relate  to  the  marine 
inhabitants  of  disUmt  parts  of  the  world  :  we  ha\e  not 
suthcient  data  to  judL'e  wht-ther  the  productions  of  the 
land  and  of  fre^h  water  cbati/e  at  distant  pouts  in  the 
s.ime  parallel  manner.  Wc  may  doubt  wluther  thev 
)ia\e  thus  c)i.ini.'i'd  :  if  the  Me;ratherium,  .Mylodon, 
.\lacr;iiicheni.i,aiid  Toxftdon  had  been  broii^^ht  to  Kuropti 
trom  Li  I'laLa,  without  any  informalioii  in  reirard  to 
their  treolotrical  position,  n«»  one  would  have  su-pe  tod 
tliat  thev  had  co-existed  witli  still  li\ini;  sea-> bells  ; 
but  .In  tlie>e  inomabtus  mon«.ters  co-existed  with  the 
Ma-.todon  and  Horse,  i>  mi::iit  at  least  have  t)een  in- 
ferred that  they  bad  lived  durni:;  one  i»f  the  later 
tertiary  stajres. 

\\  hen  the  marine  forms  of  life  are  -pokcn  ot  as 
havinj;  chan^red  sinniltaneously  throutrhout  the  world, 
it  must  not  be  supposetl  that  this  expression  relates  to 
the  s;iTiie  thousmdth  or  hundred-tliou-andth  year,  or 
even  that  it  has  a  very  strict  ^'Cido-rieal  sense  ;  for  if 
all  the  marine  aiiinials  which  live  at  the  present  day  in 
Kurope,  and  all  those  that  live<l  in  Kurojte  durintj  the 
pieitftocene  period  (an  enormously  remote  |>eriod  as 
mejwured  by  years,  inidutlintr  the  whole  trlacial  epoch), 
were  to   be  compared  with   those   now  livin'f   in   South 


(;K()I,<k;|(  AL   vSlCTI-XsiON 


291 


AnuT!r,-i  or   in   Atistnili.i,    th 


w^onld  hard  I V  \>e  .iMe  t 
liialiit 


e   most  skilful    iiatumliMt 


i>  siv  H-hethpr  til 


f  «»xi«itiji^  or  tlip 


|.lei<to,-»'n»'  iiilial.itant.suf  Kuron..  reM-rnhli-d  mostclosol 
'ho-e  of  tl'O  >oMtLt'rn    ln-niitiDln'rp.      ^n,  air.-«:ri.  Hevernl 


liiirlily  «'r»rii|'i't«'iit  oh«ervorH   helu've  that    tl 
[Todur-tinii-t  of  thf  f'lnlj'd  >tat«»-i  ar»> 
thocp   which   livrd    in    Kurojx*  d 


to 


nior«'clo«f'y  related 
iirinjf  rertaiii   later 


ertiary   >t;iire^.   than    to   tlio^p   which    now   live   her. 
it    i^  evident   that  fcwsjliferoim   \^i\. 


and    if  this    he 


so. 


lores  nf  North 


depoNifed   at   the  i-re-ent  day  on   the  hI ., 

America  would  herentter  he  liahle  to  l»e  cli.^<ed  with 
M.meuhat  older  Kiimpean  I.e.U.  N.vertheless.  |,„,kin^ 
to  a  rernotely  future  epoch,  there  cin,  I  think,  he  little 


doiiht    that    all    the 


more   modern   vmrinf    i 


namely,  the  ujiper  pliiKeiie,  the  jdei-t 

niodcrn  hed.a.of  Knrope,  North  and  ^otith  A 


Australia,  trot 
nd    t 


"  cotit.iiiiii^r  fo-<i|  reniain«  in  s 


orniatiotH, 

oeene  and  strictly 

merica.  and 


>'u,  and    Jrom   not   inclwdintr   tho^e  f< 


ome  (!(• 


only  to md   in  the  old 


)rn)' 


H 


hid 


:ce 
I    are 


er  t 


rorrerfiy  ranked  as  siriiiiltani 


mderlyin:,'  deposits,  would   h, 


II 


:n    flie  al 
h 


If  ta(  t  of  the  fornis  of  liff  char 


oils  in  a  ueidoL'ieal  sen>e. 

itrin^r  simiiltaneou-lv 


•ove  larire  sen-e,  at  di>tanf  p  n  ts  of  tl 


IS    irreativ    struck    tho«e    ad 


le  worl 


de     \ 


erneiiil    and    d'Arch 


adniiralile   ohservers,    MM 


|>,inille!i«m   of  the  (•airt'o/oio    fi 


Aft 


er    referring'    to   th 


"ornis   of   life    j,,    v 


iirio'i* 


parts  of  Kun.pe.  they  add,  'If  struck  hy  this  stri, 
^.e-iMTic,..  «e  t..rn  our  attentu.n  to  North' An.erica.  and 
tlicre  .liMONer  a  nerie^  ..f  anah-i/ous  phenomena,  it  uill 
at  ;.ear  certain   that   all    the.so   nH.diticationM  of 


leir   extinction,   and     the   introduct 


Sp»'(  i(W, 


••ariiKit  Ih«  ouiiiir   t(» 


ion   of  new   ones 


mere  changes   in   niarii 


le  ciirrentx 


or  other  cauM-^  more  or  l,.s^  loci  and  fen  j  orarv  l,ut 
df'ix'nd  on  treneral  la«>  which  -overn  the  «  hole  anin.al 
K!:.-u.,m.  M,  I{,,rrande  has  ma.ie  for.  ihle  remarks  to 
precisely  the  same  effect.  It  is.  indeed,  ,,uite  futile  to 
i'...k  to  chan:,cs  of  currents,  climate,  or  other  physical 
'■oiKiitions.  a-  tiie  caii>e  of  the>-e  srea*  m>''"*=o'  '•  -•• 
forms  of  life  throuirhout  the  world,'under 'the 'molt'  ,ii'f" 
fereiit  climates.  \V^  ,„u.st.a.s  I'.arrande  has  remarked 
look  to  s.»me  vp^vial  law      We  .hall  >ee  thi.  more  clearl  v 


f 


29; 


ON    IIIK    OKIiJIN    OF   M'h(  \t> 


v*hpti  wo  tri'il  (»i  Lilt*  |irt-i'iil  (li-.lrilnitioii  of  ori,'iMic 
liflin^H,  aiui  hixl  liow  slijflit  U  the  relation  Ix'tweeii  the 
phy-ii'.'il  <t»n(liti(iiis  of  various  coutitrie,"*,  aud  the  nature 
of  thfir  iiihaltitaii!-i. 

Ihis  yrt-at  fact  of  thf  {»,irallel  niiroession  of  tho  fortim 
of  life  tiiroii;:lioiit  the  world,  is  fx|di(ald«*  on  tlie  tlu'ory 
of  natural  M'lfction.  Ni-w  s|K'fies  are  forinfi  iiv  new 
varieties  ari»iiiL',  wliicli  liave  some  advanLaj^o  over 
older  forms  ;  and  tho-e  forms,  wliieh  aro  alrea'i\-  domi- 
nant, or  have  some  advaiil.iire  (»ver  tiie  oilier  /or?ns  in 
their  own  (•(tiintry,  would  naturally  oftenesl  ^;ve  rise  to 
new  varieties  or  mrinient  ^pe(•;eH  ;  for  the-e  latter  must 
Ik;  viitoriou-  in  a  still  hi^'lier  de^rree  in  order  to  i>e  |ir»'- 
served  and  to  survive.  We  liave  di-tinet  evidence  t»ii 
;his  JKVid,  in  the  jilants  whii-li  are  dominant,  that  is, 
wliii  ii  are  eommonest  in  tlieirown  homes,  and  are  most 
widely  diiiusfd,  havini;  jtrodueed  tlie  trreatest  niimlH.'r 
ol  n»!W  Narieties.  It  is  al>.o  natural  tliat  the  domi- 
nant, varyiniT,  and  far-spread injr  sptM'ies,  whieh  already 
liave  invadi'il  to  a  certain  extent  the  territories  of  oilier 
sj>e<ies,  should  he  those  whicli  nould  have  the  hest 
•liaiire  of  spread  injf  still  further,  and  of  tfivinjf  rise  in 
tu'w  eountries  to  new  varieties  and  species.  lheproce>«» 
of  ditfij-ioii  iii.iy  often  he  very  slow,  heint;  depemienl 
on  clitiiaLal  and  ireoifrajthical  ciianijes,  or  on  strari;re 
acci<ieiits,  hut  in  the  loni;  run  the  dominant  form>  «ill 
L'eiieially  succeed  in  spre.uliiijf.  The  ditfusion  would,  it 
is  prohahle,  he  slower  with  the  terrestrial  inhahitants  of 
distinct  continents  tlian  with  tlie  marine  inhaldtant-  of 
the  continuous  sea.  ^\  e  luL'lit  therefore  expect  to  find, 
as  we  aj'parently  do  find,  a  less  strict  liejiree  of  parailci 
succes-ion  in  the  productions  of  the  lan<l  than  t)f  the«.e.i. 

Dominant  siH-'cies  sjireadinjr  from  any  reirion  mi^irhl 
encounter  still  more  dominant  species,  and  then  their 
triumphant  course,  or  even  tlioir  exi>tpnoe,  would  cea.se. 
We  know  not  at  all  precisely  what  are  all  the  conditions 
most  tavourahle  tor  the  multiplication  of  new  and  domi- 

.......    ..,..,..;....    i...   ...^    !     41.:.. I.      ,l.__i..      _.    .1     t 

:;rt;;-.    r-Jrc-.  :cr,  ,     iruL    n  c    t.in,    i     ••:!;;:.-,    tirilFiV    Sff     ■  iial    a 

numher  of  individuals,  from  ^iviiiir  a  hetter  chance  of 
the  appearance  of  fa>oiirali!e  variations, and  that  severe 


<.Kn|,<»(,l(  AL   sr((  F>M(».s 


<>« 


»n 


fnnii»4>tition  witli  many  alrrmly  «>xixtinir  tori!\j,  wtmld  U» 
iii:.'liiy  t'avoiiraiile.  as  wnuiil  Ik*  the  [Miwor  of' spn-aiiiiiir 
:i.f(i  ii'>\v  tprrif<irio<».  A  certain  amount  (tf  iwilntioti. 
r»'nirrinc  at  lomf  intorval-t  of  titnc,  wimlil  [irofiaMy  he 
.tl-n  f'aviMiraiiU',  a-*  l»«*toro  rtplairuMl.  (  >im'  ijuarfcr  ol 
til*'  worlil  may  \n\f*  l>«'fri  iinwt  f'avouraMe  for  tlu»  pro- 
'lin-tinii  of  iii'w  an<l  flominanl  hpfcies  on  tli»«  lan«l.  ami 
arinfl.or  for  tlin-r  in  tlu*  wattT' of' t}i»>  >•«'«.  If  lwoi:nal 
n-j. ,>!.•*  liail  Immmi  for  a  lori:;  [xtioI  favouraMv  circum- 
-t  in.-ptl  in  an  P(|ual  dotrrtv,  whonever  their  iiihahifnnt-; 
met,  t[u'  liattle  wotiM  |.c  jirf>lon:,'f<l  ami  m'\»t«';  mil 
-'.m«  from  oiip  l>irthpl,it  c  ami  some  from  tin-  othi-r 
fiiijlt  hf  victorious.  Hut  ifi  the  course  nf  tim*-,  the 
tonus  dominant  in  th«  hit:li»'st  (Joirroe,  wliprpvcr  itro- 
diiccd.  ivouhi  triid  <M(>rywhcro  to  prevail.  As  tlii'v  Mre- 
va^led,  they  would  «auso  tlie  extinction  of  other  and 
inferior  forms;  and  a,'-  tfieso  inferior  forms  would  K.> 
allied  in  croups  hy  i-iheritance,  wliojo  >:roups  wouM 
teiid  slowly  to  di-an'M-ar  ;  thoiiirh  here  and  tliere  ,- 
-  Mtrle  mem^^er  micht  loti;.'  I'O  enaMed  to  nurvno. 

I'lius,  na  it  seems  to  m«>,  fh.-  parallel,  and,  taken  ir 
iarire  »ense,  simultaneous,  success. on  of  the  same  form^ 
ot  life  throuyhoiit  the  world,  accords  well  with  the  prin- 
ciple of  now  species  haviuir  heen  formed  hy  dominant 
speci,-.<  spreadinjr  widely  and  varyint:  ;  the  iiew  species 
tiius  i.Tfuiui'^vj  heir  .^  themselves  dominant  owifitr  to  in- 
heritam  e,  and  to  havinjj  already  had  Bome  advantat'c 
over  t!.»'ir  parents  or  over  other  species;  these  a:rain 
»preadi;i_'.  varyitii:,  and  firodiicin::  new  species.  l],t^ 
forms  which  aro  l)eaten  and  which  yield  their  pla.-es  to 
the  new  and  victorious  forms,  will  i^euerally  l>e  allied  iti 
rroiip^,  from  ii.hentint'  >omo  inferiority  in  common  ; 
and  therefore  as  new  and  improved  irmups  snread 
tiiroujjhout  the  world,  oM  eroups  will  disappe.ir  from 
the  world  ;  and  the  Kuccession  of  forms  in  Knt'i  wavs 
wii;  e\ervv*here  tend  to  correspftnd. 

1  fiere  is  one  other  remark  connected  with  this  subject 
w: :r;h    mak;n^.      i    i..»vf  jfiven    my  reasons   for   i>e'iev 
inir  that  all   our  lt.  ater   fo-s'Iiienuis   formations  were 
de;  wited    tlur'r.:^     peiiod.s    ..f    sul.siden.-e  ;    an<!     that 


2;»i 


ON  rin:  omkwn  ok  si'K(IF> 


itiaiik  iiii**rvai<4  oi  vaiit  tiiiratioti  ocrurrfMi  diiriiii;  tlie 
p«'rMi(ls  mIi«m  tlio  l»»'<i  'if  t.li«»  »«'.i  w.m  oithor  HUitiori- 
ary  or  riHiiii;,  and  liki't«i««>  wlini  «(vliriU'iit  w.-im  iint 
thrown  down  (jiji»kly  etiou^fli  to  ptntxMl  and  prenorve 
ofL'^inir  r«'tnains.  During  i1i«"mi  lorijf  and  tilank  inter- 
val.- I  -'ip|M»>.t«  lliat  tli«  inlialiilaMl"*  oi  each  rtvion 
undnv\)'i.ta  i Kii^idcralile  amount  o(  nioditicatioii  and 
pxtiiK  tmii.  and  tliat  tliere  wa-*  much  mitrration  from 
otiuT  |>irt-i  of'  tli«»  wori'l  Aw  wo  )ia\»'  rca-uti  tn 
i>rii»'Vt'  that  lartT'"  aroan  are  a(r<'<t«»d  I'V  thf  -..iinH  nmvt*- 
nitMif.  It  iH  proii.iiil«  that  Hlricll)  coiiTjMnpnranJMtu^  t'or- 
ni.iliMi,,  have  ofton  l»«M»n  a<rii'niila!>'ii  ov<>r  v»<ry  -^ido 
•ip.H'tw  Ml  thf  !.afnf  I'lartiT  ot  the  world  ;  hut  we  ar« 
far  fnoii  havini;  any  ri;:ht  to  roucluile  thai  this  hi-  in- 
variaMy  Immmi  tht»  «ax«*.  at»d  that  hir^r  areas  hav«  iii\ari- 
al>i\  'irtMi  at?<  rtod  hy  t}if«  same  mttv^-mt'ntjH.  W  li«»n  two 
tor  !iiatii>ii>t  ha\e  h«*«'n  drpo-iti'd  ni  •.**.»  rfxioii.*  dwini; 
n«*arly.  loit  not  exactly  tho  K.imo  p«'riod,  we  hlionld  find 
in  liiiifi.  from  tlie  rni>.«'s  cxplaiiiwl  lu  tlu"  foreyoin^  ["ara- 
trraph-.th»>  •vinie  L'»*ner.il  suciession  in  the  fiirin«i  oi  hi-; 
loit  tijf  «.p<'cit>«  would  ijot  exactly  corresjMind  ;  for  liiere 
V*  lij  lia\ »?  Uhmi  a  little  more  time  in  t  lie  one  region  than  in 
the  other  tor  miniiti.  ation,  extinction.  an>l  i  mm  iteration. 
I  >.ii»pect  tli.'vt  c.i-es  of  this  natiiro  (Mciir  in  Kuro|»^». 
Mr.  rrf>t\M>  h.  in  hi^  a<imirahle  .MemoirH  on  the  eoi'ene 
.icpovlt..,  of  l!ii;.'laiid  ami  Irance,  is  aide  to  draw  a  close 
i.'iMiei  il  iiara!li'li-m  Ix'twecn  the  Huccossive  st^iijeii  in  the 
two  .Kiintrio;  hut  when  ho  compare-  certain  Ktaire** 
in  Kiiirlaiid  with  tlm-e  in  f-'rance.  althcuirh  he  finds 
in  hoth  a  curious  accordance  ia  the  uuiiii)ers  of  the 
-pecies  iH'loiitrin;;  to  the  same  tfonera.  yet  the  sj>«»r'es 
tne;iisel\ f-  differ  in  a  manner  very  dithouk  to  account 
for,  con-iderint:  the  j«.-oximity  of  the  two  area-,  —  unh'ss, 
indeed,  it  !►«  a.— umod  that  an  isthmu-  s»'[>araterl  two 
-eas  iiilialiiled  h\  ili.-tiiict,  iiut  cotitempuraiieous,  (auiias. 
L\ell  ha-,  made  similar  oli-ervation-  lui  some  of  the 
later  tertiary  t'orMi.iliitns.  liarrainie.  .ilso,  hhowti  tint 
thix-e  i»  a  -tnk'iiir  irMricrjij  rvirjilleli.Ki  in  fh.e  succc«»«ive 
>iliir:.in  deposit-  of  llohcona  and  ."scandinav  ia  ;  never- 
tlielev-    lie   find-  a  -ur[)ri-iii::  amount  of  diiierentte   ia 


(;K(>L(m;i(  Ai,  Mcc  ».si<)\ 


;>ft 


trie 
on- 

liot 

rvf 


hikI 
from 

I     to 

lOVtV- 

V*  iiie 
I   arH 

•*  in- 

vari- 

tvvo 

rind 
'.'i  ra- 


le re 
II  iii 


•fiie 
the 

tlie 
iiiit 


the 


•  1  •»  -|'«'ii»>».      If  the  xevcrul  formittioiH  iii  theM^  reifioiii 
li  ivf  not  Ikm'ii  ili'|»<»«jit»'<l  iliiriiitf  tlie  Kiine  exact  |K>rnMl« 


•a  f( 


orm-.tinti   III   dill'   rr;.';(iti  ottrii  rorre^poiiihinr  »i 


ith 


.»  Iil.iiik  iiifiTvil  in  the  otiier,— ami  il  in  Initli  rririoim 
flie  "-[KMuw  h.n"  L'"ne  on  '■lov«  I>  r!u->nifinjf  iluriin;  the 
•<  ••iiiinii.i'ioii  ot  \\n'  xrMT.ii  tortii.itiori-*  aii'i  iliirintf  tin* 


iontr 


;  iiiNTV.iN  lit' time  lie'.weon   tln'in 


in   tl 


lis  r;i>«- 


th 


^♦»»'r:il  tonii.itif'iH  in  th»"  two  rrj^ious  roiilil  U' arr.'ni.'ivl 


111  till'  ■..line  or  liT.  in   ;i.  tiir<l.i/ii«'  wi 


11.  tl 


le  jfiMier.il  -in- 


rf>>- 


m  o(   tin-  liirni  of  hfe,  and  tlie  orih-r  wnnhl  faUelv 


apiit'iir 


to  1 
not 


x'-triitly  |i.irall«M  ;   tn'\«'rti.tMe«*8   the  himth'*. 


ill 


>♦'    tilt'   ■siiiie    III    till'   apparciitlv  rorre- 


HjMirnlint.'  ^taire-  m  the  t.»o  nvons 


< '/I  ih,   Ajfiiiitirx  lit  I  lUiiil  >'/ 


«•(>»'.«  tit  fill 


h  iiifi 


tfr,  mil 


t 


lu'inii  i,.rf'i.s.  —  \A'\  IIS  now  look  to  tlu-  nuitnal  afFinities 


>f  ext 


Uirt    .nil 


1    1 


1  \  I  n ;: 


I  liev  all    full    into  one 


Ifratid  ii.iiiiral  •.y«itiTn  ;  ami  l!ii>.  fact  is  at  nnoc  rxiilaim'tl 
on  (he  |irim  ijile  of  (i»'»oont.  ilio  more  amimt  aiy 
form 


the  inori*,   as  a  cciiiTal    rule,   it  <lit!«T-.    from 
living  loriii-.     Mat,  as  jlin  klanii  loiij;  atj*)  reiiiarknl,  all 


to^ 


»; N  ran   in-  cm- 


eithr 


>>till  exi>tinjf  i:ron|».,  or 
het«(«on  thrill.  I  hat  the  extinct  forms  of  liU'  In  ![>  to 
till  lip  the  wile  intervals  l»etv»een  existing:  K'enera.  taiiii- 
lies,  ami  onlcr*.  cannot  he  (li»|tut»'il.  lor  ifw»>  conline 
our  at'r:it  ion  either  to  the  living  or  to  the  extinct  alom>, 
tlie  M'r.c«  ;s  far  lens  perfect  than  if  wt- comhiiu*  hoth 
into  nne  L'cncral  hy'-tem.  \V  ith  re^pt'ct  to  the  \'erU'- 
hrata,  «hoIe  [Kiires  could  ho  tilled  \\,th  >trikin;:  illustra- 
tion- from  oiirirreat  palieontolot'i-t,  (  iwen,  showini;  how 
extitu-t  aiiinial>  fill  in  hctueen  exi-tiiij;  >.'roup>.  (  u\  ier 
rankt'd  tin-  Kuniinants  and  I'ai  liyderiii-.,  as  the  two  most 
di.sliuct  orders  of  niaminals  ;  hut  Owen  han  discovered 
so  nianv  fo-.-il  links,  that  he  has  had  to  alter  the  whole 


-ill, 


alion  of  the>e  two  order-  ;  and  has  placet!  certain 
pachyilcrms  in  the  sjime  auK-oriirr  with  ruininantH  :  for 
f\aiiiplr,  he  lii.— olves  hy  tine  ;;radalions  the  apj>arentl\ 


dc    llitf 


)...ti 


I'een  the  iwi^  hiu!  thp  ivtiiif^!  !*■ 
rejard  to  the  liivt-rteiirata,  llarramle,  and  a  hi^'her 
authority  could   not  W  named,  a— crt.-  tliat  he  is  every 


•jim; 


ON   THK   OKUJIN  OF    SI»K(IKS 


ilay  t'lii^'ht  that  Palnxv/oic  animal^,  though  heloriirinif  to 
thf'  same  orders,  families,  or  ;:i'nera  witli  those  livmiT  .it 
liie  i>reseiit  day,  were  not  at  this  parly  epoch  limited  iii 
Kiicli  distinct  tr'rniips  as  they  now  are. 

Some  writer^,  liave  ohjected  to  r..'y  extinct  sjK»ries 
or  trroup  of  species  heint,'  con>^iilered  as  intermediate 
hetween  livinir  species  or  trr<tup<.  if  liy  this  term  it  is 
meant  tliat  an  extinct  form  is  rlirectly  intermciliate  in 
all  its  characters  between  two  livinjr  forms,  the  objec- 
tion is  prohahlv  \alid.  liut  I  apprehend  that  in  a 
perfectly  natural  dassifiration  many  fossil  species  would 
have  to  stand  hetween  livinj;  specie^,  and  some  extinct 
trenera  hetween  livintr  e.-nera,  even  iietween  jfenera  be- 
hm;ri,,ir  to  distinct  families.  Ih.-  most  common  case, 
especiallv  witli  respect  to  very  <!istinct  irroups,  such  a> 
fish  and  reptiles,  seems  to  he,  Uiat  supp<t>inir  them  to  be 
distin^fiiished  at  tiie  present  day  from  each  otlier  hy  a 
dozen  characters,  the  ancient  memhers  of  the  same  twc. 
•rroujw  would  l>e  distintfuished  hy  a  somewhat  lesser 
numi.er  of  characters,  so  that  the  two  eronps,  though 
formerly  ([uito  distinct,  at  that  period  made  some  stnnil 
approach  to  each  other. 

It  is  a  common  helief  that  the  more  ancient  a  form 
is,  hy  so  much  the  more  it  tends  to  connect  hy  some  of 
its  characters  trroui)s  now  widelv  separated  from  ea<  h 
other.  'Ihis  remark  no  doiiht  must  he  restricted  to 
those  ffroups  which  have  undergone  much  chantre  in  the 
course  of  treoloirital  atfes  ;  and  it  would  he  difficult  to 
prove  the  truth  of  tiie  })roposition,  for  every  now  and 
then  even  a  liviii-r  animal,  as  the  Lepidosiren,  is  dis- 
i-(tvered  havint:  affinities  directed  towards  very  distiuct 
^rroups.  Yet  if  we  comyiare  the  ohler  Ileptiles  and 
r.atrachians,  the  older  Fish,  the  older  t  ephalopod?,  and 
the  eocene  .Mammals,  with  the  more  recent  members 
of  the  same  classes,  we  niu.st  adnnt  thut  tliere  is  some 
truth  iu  the  remark. 

litt  us  ^ee  how  far  these  several  facts  and  inferences 
...     .1       .1  !•    1 ,  —  1   — '*^    «,.,.i;t;.>nf;^.r^ 

ill'l'oni     **iin     tuo     i.hi'<'i~y      '•'      HCM-C.  ■•     rr..ii     :..• -i .  .:--n-.  .•   -.^ 

As  the  subject  is  sDmewhat  complex,   i   must  refjuest 

the  reader  to  turn  to  li  e  dia^^ram  ia  tlie  prelim'tiary. 


tm^'Mmt^M 


(^.EOIXHilCAL   SUCCESSION 


297 


\V  f  may  sujuKwe  tliat  tlie  iiiitnhor«sl  Iftters  n>present 
ifeiiera,  and  the  ilotted  Vmo-*  <liver:;;n:;  from  th»'m 
the  fijM'iipsi  in  oadi  fftniiis.  The  diatrram  is  much  t(n> 
-impii',  ton  few  ^renera  .iml  ton  few  specie'*  l>«'inu: 
tiveii,  l>ut  ihi-s  is  uninipDrtarit  for  us.  'I'he  luiri/ontal 
line-;  nutv  re[>rpsent  gucces-sive  ffcolotric'il  forinatioiis, 
and  all  the  forms  hotioath  the  iijtpermost  lino  may 
he  considered  a>  extirut.  llie  tliree  cxistintr  :r<'iiera, 
''S  ?'*?  /''*•  ^^''^  ^"'""'  ''  small  tamily  ;  ^'*  and  / '*  a 
closely  allied  family  or  suh -family  ;  and  o",  f'\  m'*,  a 
tliini  Vamilv.  'i'iie'^e  three  families,  totrether  with  the 
many  extinct  iTenera  on  tlie  several  lines  of  desceiit 
li  'crtrinir  from  the  parent- form  (A),  will  r.irm  an 
iinier;  for  all  will  have  inherite«l  .--omctliinir  in 
common  from  their  ancient  ami  common  proircnitnr. 
On  the  principle  of  the  continued  tendency  to  diver- 
gence of  character,  wliich  vva><  formerly  illu-tr:it(Ml  hy 
fhis  diatrrann,  the  more  recent  any  form  is.  the  more 
r  will  trenerally  ditTer  from  its  ancient  prn.jcnitor. 
Hence  we  can  iind<>r-'tand  the  rule  that  ii;e  mo^l 
.mcient  fossils  diri^er  most  from  existing;  form-.  NV  e 
mu«!t  not,  however,  assume  that  divergence  of  char- 
urtr  is  a  necessary  contingency  ;  it  depends  solely  on 
Uio  despiindants  from  a  speci'^s  beini?  thus  enahled  to 
seize  on  many  and  different  places  in  the  economy  of 
nature  'I'heretore  it  is  quite  posiiihle,  a.s  we  have  seen 
in  the  ca.se  of  some  Silurian  forms,  that  a  specie-  mijrht 
tro  on  hein^  slifrhtiy  moditie^l  in  relation  to  its  sli-htly 
altere<l  conditions  of  life,  and  yet  retain  throughout  a 
vast  periwl  the  same  general  characti^ristics.  lliis  in 
repre-enled  in  the  diairram  hy  the  letter  k'*. 

.\li  the  many  forms,  extinct  and  recent,  (iocended 
from  <A),  make,  as  hefore  remarke«l,  one  order;  and 
this  order,  from  the  continue*!  ertVi-t«  of  extinction 
and  diverg'ente  of  character,  ha-«  Wcome  ilivided  int*; 
•cveral  sub-families  and  families,  some  of  which  are 
supposed  to  have  perished  at  different  periods,  and 
cnr'if  to  have  endtjred  to  the  iiresent  d;\v. 

Uv  loc-kiiiiT  at  the  diairram  we  can  see  tliat  if  many 
of  tho  extinct   forms,  sujijxised   to   lx»  emhcd  ied  in  'he 


3-- 


ur'^i 


u 


\i  I 


TM  ON   TllK   ORir.IN   OF   Sl'KCIKS 

(,uc.-,es«ive  tortnatif.ns  werp  (liM-ovcrea  at  spvoral  poiiiU 
low  .lown  in  the  series,  thf  three  existiiifr  lamilies  on 
the  uppermost  line  would  he  rendered  less  distinct 
from  e;u-h  other.  If.  «or  in^tan.-e,  the  irenera  a\n\ 
.(I'J  n  m^  m«,  m->,  were  disinterred,  these  throe 
tiiuiiies  would  ho  m  clo^elv  linked  totrether  that  they 
prohahly  would  have  to  he  united  into  one  trreat  family, 
in  ne.-irlv  the  same  manner  as  ha'^  (Kourred  with 
rum.niuts  and  parhv<ierms.  Vet  he  who  ohjeeted  to 
rail  the  evtin.t  LM'iiera.  «liioh  thus  Iniknl  the  livmif 
peiiera  of  three  families  toirether,  interinehate  in 
chara.ter,  would  he  justified,  a.s  they  are  :nterme 
diate.  not  dirertlv,  hut  only  hy  a  lon^'  and   circuitou-, 

, ,.  throuffli  m'anv  w;:"lv  dilTerent  forms.      If  mam 

..xtim-t  forms  were  to  he  discovered  ahove  one  ot  th.- 
■  „i.ldlo  horizontal  lines  or  eo.dotrieal    forniati.ms- for 
,nsU!i<e.  ahove   No.  VI.  -hut  none  Irom  he:u-..th   thii 
Ime     tlien    onlv    the    two    families   on    the    lett    .lai.'l 
fnarnelv,   «'*,   etc,   and    />'«,    etc.)   would    have   to   U- 
united' into  one   f.imilv  :    and    the   two  other   tamiliei- 
(iiamelv,^;'*  to  /'«  now  inrludlnj;  hve  trenera.  and  o 
to  mi<)'w..uld  vet  remain  distinct     'Hiese  two  iamilies, 
however,  vso.il'd   he  les«  distinct  from  each  other  tha.i 
Ihev  were  hefore  the  discovery  of  the  tos.siis.      M,  tor 
instance,  we  suppose  the  existing  frenera  of  the   two 
families  to  differ  from  e.ach  other  hy  a  dozen  characters, 
in  this  case  the  K«nera,  at  the  early  period  marked  \  1., 
wrMild   differ   hva  les<er  numher  of  character.-;  foi  at 
this  oarlv  stii-e  of  descent  they  have  not  diverged   in 
character  from  the  .vommon  progenitor  of  the  order, 
nearly  ^o  much  as  thev  suhse.|uently  diverged.      I  hu.« 
It  conies  thai,  ancient  and  extinct  genera  are  often  m 
Pome  slijhi  detrree  intermediate  in  character  hetween 
♦heir  mod'ued  de-con<lant^,  or  hetween  their  coUat.-rai 

'  *"  hinature  the  ra-e  will  \^e  far  T.iore  complicated  than 
u,   represented    in   the    di;itfram  ;    h;r   the  jrroups^wiU 

liave  i n  more  numerous,  they  w.ii  navo  c:iu;;rr<;    u^r 

extremely  une.iual  len-ths  of  time,  and  will  have  heen 
rno.litied   in   various  de-rees.      /\s  we  ikj.-^nss  only  the 


GEOUHJILAL   sm  ESSION 


20ii 


la>r  volume  of  the  peoloirical  record,  and  that  iu  a  very 
broken  condition,  we  have  no  ri^ht  to  expect,  except 
in  very  rare  cii.M<s,  to  till  up  wide  interval»  in  the 
natural  syHteni,  and  thus  unite  distinct  families  or 
orders.  All  that  we  have  a  ri^ht  to  exjKH-t,  is  that 
those  irr<)iiji>,  wliiili  have  within  known  tfeolotrical 
periods  UMd»'r>^()iie  much  modification,  should  in  the 
older  formations  make  some  flight  approach  to  ea«h 
other;  so  that  the  oldor  menilnTS  should  differ  le^'* 
from  each  other  in  some  of  their  characters  than  do 
the  existing  members  of  the  same  ffroups  ;  and  this  hy 
the  concurrent  evidence  of  our  i>est  pal»ontolo«-i-- 
seems  fre<;uently  to  l*  ilie  Ciise. 

Thus,  'til  the  theory  of  descent  with  modification,  tii^ 
main  f"  ts  with  respect  to  the  mutual  affinities  of  the 
extinct  uirms  of  lif«  lo  each  other  and  to  livirijf  forrn-^, 
seem  to  me  explaine<l  in  a  satisfactory  manner.  And 
lliey  are  wholly  inexj)lic^ihle  oi;  any  other  view. 

On  this  same  theory,  it  is  evident  that  the  fauna  i)t 
any  ijreat  j)eri<»d  iu  the  earth's  history  will  he  inter 
mediate  iu  jr«i»eral  character  between  that  which  pre- 
ceded anil  that  which  succeeded  it      ITius,  the  8|>eci»'.- 
\    'ich  lived  at  the  sixtii  >;reat  sta^e  of  descent  in  tlie 
diairram  are  the  modified  ulf>prinf(  of  those  which  lived 
at  thf  fifth   sla«e,  and  are  the  parents  of  those  whicii 
l)©camt'  ^tiIl  more  modified  at  the  seventh  sta^e ;  hence 
they  could   hardly   fail   to  be   nearly   intermediate   in 
character  between  the  forms  of  life  above  and  Ik'Iow. 
\^'e  must,  however,  allow  for  the  entire  extinction  ot 
some  j.recediujf  forms,  and  in  any  one  region  for  tli*- 
immitrration  of  new  forms  from  other  re^ous,  and   n.r 
a  lariTf  amount  of  modification,  during  the  long:  a'..i 
blank     intervals    between    the    »uciessive    fitrmalinni. 
Subject   to    these  allowancen,  the   fauna   of  eA<-h   ue<v 
lotri'al    [leriod    undoubtedly    is   iiilerinediate    in    cliar- 
acter.   Iwitween  the  preceding:  and  sucreedinjf   fauiia.'^. 
I  nt'cd  cfive  only  one  instance,  namely,  the  manner  iu 
which  tb.e  fn«sils  of  the  Devonian  system,   when    thia 
system  was  firiit  discovered,  were  at  once  recog-ni^ed  by 
paln'ontologists  as  intermediate   in  character   liotwe^  n 


.3(X) 


ON    IHE   ORIIJIN-    OF   SI»K(  IKS 


^l; 


\\ 


those  of  tlie  overlying  oirlirtiiiicrous,  and  uriflerlviiig 
Silurian  system.  Hut  c.ich  faiiiia  is*  not  necessarily 
ex.utly  intermediate,  as  uneijual  intervals  of  time  liave 
elapsed  hetween  (-((nsecutive  formations. 

It  in  no  real  objection  to  the  truth  of  the  statement, 
that  the  fauna  of  each  period  as  a  whole  is  nearly 
intermediate  in  character  hetweea  the  precedina^  and 
ucceedinij  faunas,  that  certain  irenera  otfer  exceptions 
to  the  rule.  For  instance,  mastodons  and  elephants, 
when  arraii^fed  hy  Dr.  Falconer  in  two  series,  first 
accordiny:  to  their  mutual  affinities  and  then  acconlinj? 
to  their  periods  of  existence,  do  not  accord  in  arrantri'- 
ment.  Hie  species  extreme  in  chamcter  are  not  the 
oldest,  or  the  most  recent  ;  nor  are  those  which  are 
intermediate  in  character,  intermediate  in  ajfe.  Hut 
sup[ioMnjf  for  an  instant,  in  this  and  other  such  ca.se9, 
♦hat  tlie  record  of  llie  first  appearance  and  disappear- 
iiice  of  the  species  was  perfect,  we  have  no  reason  to 
helieve  that  forms  successively  produced  necessarily 
endure  lor  correspon<linif  l(«n:rths  of  time  :  a  very 
ancient  form  niiL'ht  occasionally  last  much  lonjjer  tliai'i 
a  form  elsewhere  subsequently  produced,  especially  in 
the  ca>e  of  terrestrial  productions  inhahitine:  separated 
districts.  To  compare  small  thinps  with  ^^reat  :  if  the 
principal  living  and  extinct  races  of  the  domestic 
piijeoii  were  arranired  as  well  as  they  could  be  in 
•<erial  affinity,  tliis  arraiiiioment  would  not  closely 
accord  with  the  order  in  tinio  of  their  production, 
and  still  less  with  the  order  of  their  disappearance  ; 
for  the  parent  rock-piijeon  now  lives;  and  many 
v:iriet;os  between  tlje  rock-pia^eon  and  the  carrier  have 
I),  come  extinct  ;  and  carriers  which  are  extrtme  in 
the  important  character  of  length  of  beak  orig^inatcd 
earlier  than  short-beaked  tumblers,  which  are  at  the 
oppo>ltp  end  of  the  series  in  tliis  same  respect. 

Closely  connected  witli  the  statement,  that  the 
ori^nic  remains  from  an  intermediate  formation  are 
III  some  decree  intermediate  in  character,  id  tiie  t:ict, 
iusiste<l  on  by  all  p.-ua-ontolo^qstiii,  that  fossils  from  two 
consecutive   format  ion-  are  far  more  clo*<e!v  related  to 


GEOUHiK  AL  SUCCESSION 


.'W>| 


each  other,  than  are  the  fo*sih  from  two  remote  forinri- 
tions.  Piftet  ifivea  an  a  well- known  insUmce,  tl't- 
fjeneral  resemblance  of  the  organic  remains  from  tlie 
Kevoral  stamen  of  the  Chalk  formation,  thoujfh  thr 
s;>e<'ics  are  distinct  in  each  sUi^e,  Iliis  fact  aloin-. 
from  its  generality,  seems  to  have  sliaken  Professor 
I'ictet  in  his  tirin  lielief  in  the  immutability  of  specuw. 
ile  who  is  acquainted  with  tlie  distribution  of  existiiitr 
sj>ecies  over  the  *clo'»<^,  ^^'^  not  attempt  to  account  to; 
tiie  close  resemblance  of  tlie  distinct  species  in  closely 
consecutive  f>vrmat'ons,  by  tlie  physical  conditions  of 
the  ancient  areas  having  remained  nearly  the  same 
Let  it  be  remembered  that  the  forms  of  life,  at  lea.si 
those  inhabiting  the  sea.  have  chan)re<l  alnjost  simul- 
Umeously  throughout  the  world,  and  therefore  under 
ihe  most  different  cliniates  and  conditions.  Consider 
the  prodigious  vicissitudes  of  climate  during  the  pleisto 
leue  period,  wliich  includes  the  wlude  glacial  period. 
;ind  note  how  little  the  s|)ecific  forms  of  the  iuhabiunt- 
of  the  sea  have  been  ath'cte<l. 

Ou  tlie  theory  of  descent,  the  full  meaning  of  the 
lact  of  fossil  remains  from  closely  consecutive  forma- 
tions, though  :auked  as  distinct  species,  being  closeK 
related,  is  obvious.  As  the  arcumulation  of  eacJi 
formation  has  often  l)eeu  interrupted,  and  as  lent' 
blank  intervals  have  intervened  between  successive 
formations,  we  ought  not  to  ex|>ect  to  find,  as  I 
att'mpti'd  to  show  in  the  last  cliapter,  in  .iny  one  or 
two  formations  all  the  intermodiate  varieties  In-twoen 
the  species  which  apj)eared  at  the  commencement  and 
close  of  these  periods ;  but  we  ought  to  tind  after 
intervals,  very  long  as  mea.su red  by  years,  but  onlv 
moderately  long  as  measured  geologically,  closelv 
allied  forms,  or,  as  they  have  been  called  by  s.im'e 
author-.,  renre-sentative  spe,  iei<;  and  these  we  ;ts.suredly 
do  tiii.l.  U'e  find,  iu  short,  such  evidence  of  tlie  slow 
and  scarcely  se:Lsible  mutation  of  speciiic  forms,  aa  we 
have  a  just  n,;?ht  to  expect  to  find. 


On  the  state  of  Uetielopnunt  of  Anci<»i  /■'omwr.-  -There 


302  HN   TIIK   ORUJIN    OF   SPEC  1F>» 

ha-  been  much  discusfiion  wh»'ther  recent   forms  are 
more  hitfhlv  devrlopfd  than  ancient.      I  will  not  here 
enter  on  this  sul.ject,  for  naturalists  have  not  as  yet 
drfui.'rt   to  each  othcr'n  satisfaction  what   is  meant  by 
hi-'h  an.l   low  forms.     'Hie  best  definition  prot-aMy  \?, 
that  the  hi^'her  forms  have  their  orjrans  more  dislinct.y 
cpecialised  for  ditfereut  functions;  and  hs  such  division 
of  idu-    .loiri»al   lalM.ur  scrns   to  b-  an   advant.-ure  to 
each  beintr.  natural  selection  will  cnstantly  tend  in  »o 
far  to  make  tlie  later  and  more  moditi.d   forms  hitfber 
Ihan     their    early    prot:enitr)rs,    or    than     the    sli;rbtly 
modified  descendantw  of  such  proijenitors.      In  a  more 
general    sense    the    more    recent    forms    tnust,   on    mv 
theory,  be   hi^rher   than  the   more  ancient  ;    for  each 
new  «iM'<-i'''*  'S  f<'""<''l   by  haviiit:  had  some  advanta^fe 
in  thestrutr^le  f<.r  life  over  other  and  preceduiir  forms. 
If  under  a  nearly  similar  climate,  the  eocene  inhabit- 
ant.s  of  one  .piarter  of  the  world  were  put  into  com- 
petition  with   the  existing'  inhabitants  of   the  same  or 
8ome  other  (juarter,  the  eocene  fauna  or  flora  would 
certainly    be    beaten    and    exterminated  ;    as   would    a 
M-condarv  f.uiiia  by  an  eocene,  and  a  pabeozoic   fauna 
bv    a   secondary    fauna.       I    do    not    doubt    that    this 
n'rocess  of  impruvenuMit  has  affected  m  a  marked  and 
sensible  manner   the  ortranisation  of  the  more   recent 
and   victorious  forms  of  life,  in  comj-anscm  with   th.- 
mcient  and    beaten    forms;    but  1  can  see  no  way  c-t 
testintf    tliis    sort    of   pm^rress.       Crustaceans,   ft.r    in- 
stance, not  the  hiL'best  in  their  own  class,  may  have 
beaten  the  hiL'best  molluscs.      From   the  extra-^rdinary 
manner  in  winch  Kumpean  productions  have  recently 
-priad  over  New  Zealand,  and  have  seized  on  places 
«hich  must   have   been   previously  occupied,   we  may 
believe,  if  all  the  animals  an<l   plant,  of  Creal   liritairi 
were  set  free  in  New  Zealand,  that  in  the  course  of 
Time    a    multitude     of    British     forms    would     become 
thoroughly  naturalised  there,  and  would  exterminate 
many  of  (hv  natives.      On  the  other  |::-!id,  im^-^--  w.'^- 
we    <ee    now    occurrinsf    in    New    /ealainl,    and     fn.i.i 
hardly  a  sin^-le  inhabitant  of  the  southern  hemisphere 


GEOUK'.IC'AL   SIC  (  h:ssiON 


:viii 


}.t\iii><  become  wild  in  any  part  of  Kiirope,  we  may 
<l(juKt.  if  all  the  priwliictioiis  of  Zew  Zealand  were 
«et  tree  in  (Jreat  Britain,  whether  any  considerahle 
mimher  noiild  he  ennhled  to  seize  m\  placen  now 
o<<-upied  hy  our  native  plants  and  animals.  I'ndcr  thin 
point  of  view,  tlie  productions  of  (treat  IJritain  may  he 
«^iid  to  helii^her  thanthoseof  N«'^  ZeAlatMJ.  ^  ft  the  most 
>'kilful  naturalist  from  an  examination  of  the  species  <tf 
the  two  countries  could  not  have  foreseen  thi-  result. 

A^rassiz  insists  that  ancient  animal-  resemhle  to  a 
I  ertain  extent  the  eml»ryos  of  recent  animals  of  the 
»ame  classes  ;  or  tliat  the  jfeoloi.ncal  8'.icces>ioti  of 
extinct  forms  is  in  some  detrrce  parallel  to  the  eiii!»ryt>- 
hiLHcal  d«'\eloprnent  of  rercnt  forms.  I  must  tolfow 
I'Htet,  and  Miivley  in  thinkin;):  that  the  trutli  of  thi^ 
doctrine  is  very  far  from  proved.  Vet  I  fully  exiMM-t  to 
see  it  hereafter  confirmed,  ;it  least  in  reirard  to  snl.ordi- 
nat»>  t^^rniips,  which  have  hranched  otT  from  eacli  other 
witiiin  comparatively  recent  times.  For  this  doctrine 
or  .Afrassi/  accords  well  with  the  theory  of  naturaUelec- 
tioii.  In  a  future  chapter  I  sliall  attempt  to  slmw  that 
tlie  adult  differs  from  it«  embryo,  owiiiij  to  variations 
supcrveiiinn' at  a  not  early  ag-e,  and  bein^  inherited  at 
a  corresjM)ndinir  a^e.  This  process,  whilst  it  leaves 
the  emhi-yo  almost  unaltcn-d,  contiiuially  adds,  itj  the 
course  '.f  successive  ^fenerations,  more  and  more  diifer- 
ence  to  the  adult 

I'll  us  the  embryo  comes  to  Ui  left  aa  a  sort  of  [licture, 
preserved  hy  nature,  of  the  ancient  and  less  nioditled 
condition  of  eiich  animal.  This  view  may  he  true,  and 
yet  it  may  never  he  capaMe  of  full  proof  i>eeini,',  for 
in-tan.  c,  that  the  olde>t  known  mamrnals,  reptiles,  and 
li-h  strictly  beloiiir  to  their  own  pro{)cr  clas.->es,  thoutrli 
<ome  of  these  old  forms  are  in  a  -li^ht  detrree  less  di>- 
timt  from  each  other  than  are  tiie  typic.l  members  or 
tlie  same  t.^roups  at  the  pre<etit  day,  it  «..uld  he  vain  to 
look  tor  animals  havinj,''  the  connnon  enihryoloi.'-ical 
character  of  the  WrtcbratH,  until  beds  far  K'ciH'.itb  t};*' 
lowest  Silurian  strata  are  discovered— a  «li.scovery  ot 
which  the  cliance  is  very  ^mall. 


ao4 


ON   rnK  oiur.iN  or  .spe(  iKS 


I 


h^'-\ 


(^i  tlw  ^uccf-stoon  ft/  tilt'  aumr  Tyju-x  viffitu  t/ie  siimti 
arian,  during  the  lati-r  trrtiary  perimls.  —  Mr.  (  lift  many 
yo^irs  .iL''"'  hhowed  that  the  fossil  maimnals  Iroin  tlio 
Aiistraliaii  caves  were  closely  allied  to  tlie  liviii>f  mar- 
siiDials  i)t  that  coutiiu'ut.  In  South  America,  a  similar 
relationship  is  manifest,  even  to  an  uneducated  eye,  in 
the  trit'^antic  pieces  of  armour  like  fho>e  of  tiie  artn;i- 
diilo,  f(»un(i  in  several  parL>  of  i-i  I'l.ita  ;  and  rrorej;>or 
<  )weM  \\;\s  shown  in  the  most  strilvin;;  .nanner  that  nio.-^t 
of  the  fossil  mammals,  huried  there  in  such  nuiiiher?., 
are  relate<i  to  South  A'lu-riian  tyiM'>  'W'l^  r<>Iatii)ii- 
nhip  is  even  more  clearly  s»H'n  in  tiie  wonderful  collec- 
tion of  fossil  huTies  made  hy  .MM.  Lund  ami  (  lausen  in 
the  caves  of  Jirazil.  1  was  so  much  impressed  witli 
♦;iese  facK  that  I  stron^^ly  in>i^ted,  in  ll{.'>i>  and  lo-l."i, 
nil  this  "law  of  the  succes-ion  of  types." — on  "thiM 
wonderful  relation^liip  in  tlie  srime  ('ontinent  i)etween 
the  dead  ami  the  livinir.'  Professor  ( )\ven  has  Kuhse- 
(juently  extended  the  s;ime  trenerali<ation  to  the 
niamm.il'  of  tiie  Old  NV'orld.  \\e  see  the  same  law  in 
this  aiitlior's  restor.it ions  «»f  the  extinct  and  pi^n^ntic 
hirds  of  New  Ztaland.  W'ti  see  it  al-o  in  the  hirds  of 
tiie  caves  of  !'>r;i/.il.  .Mr.  W Oodward  has  shown  that  the 
Kime  law  holds  ^'ood  with  sea-shells,  hut  from  the  wid,- 
distril)ution  of  mo>t  irenera  of  mollusc^,  it  is  not  well 
displayed  hy  them.  Other  c^ses  could  1h*  added,  as  the 
relation  hetween  tho  extinct  and  living  laiid -shells  of 
Madeira  ;  and  hetween  the  extinct  and  living  hrackish- 
water  shells  of  the  Aralo-Casjtian  Sea. 

Now  what  does  this  remarkalde  law  of  the  succession 
of  the  s;»ine  types  witjiin  the  same  areas  mean"'  He 
v\ould  l>e  a  hold  man,  who  after  comparint;  tiie  present 
climate  of  Australia  and  of  {)arts  of  South  America 
under  the  s;ime  latitude,  wouhi  attempt  to  account,  on 
the  one  hand,  hy  di  .simihir  jihysiciil  condititwis  for  the 
dissimilarity  of  the  inhahitants  of  these  two  continents, 
and,  on  the  otlier  haiitl,  hy  similarity  of  condition;-,  for 
the  uniformitv  of  the  s;ime  tvpes  in  eacli  durin/r  tim 
later  tertiary  periods.  Nor  can  it  he  iiretendeti  that  it 
U  au  immutiilue  law  tliat  marsujtials  should  have  heen 


C^EOLOGICAL  SUCCESSION 


nOA 


rliiRfly  or  ^lolcly  produced  in  AuHtnilia  ;  or  that  K«len- 
Ut.i  and  other  Amerir.iri  typcM  should  have  Wen  solely 
produnMl  in  South  Anjorica.  Tor  we  know  that  Kurop.. 
;ri  aiK-ieut  timcM  wan  ppoplod  hv  numerous  marsupi.iU  ; 
and  I  have  shown  in  the  puhliratioris  ahove  alluded  to,' 
that  in  America  the  law  of  di«trihutiun  of  terretitrial 
niaininals  \v;w  formerly  ditferent  from  what  it  now  is. 
Nortli  Ameri.-a  formerly  partook  stroritrly  of  the  present 
character  of  the  southern  half  of  the  continent  ;  and 
tlie  southern  half  was  formerly  more  closely  allied,  than 
It  IS  at  present,  to  the  nortliern  lialf.  'in  a  similar 
manner  we  know  from  lalconer  and  Cautley's  di>- 
coveries,  that  northern  India  was  formerly  more  closely 
related  in  its  mammals  to  Africa  tlian  it  is  at  the  pre- 
sent time.  Anaiop)us  facts  could  he  jfiveii  in  relation 
to  the  (Jistrihulion  of  marine  animals. 

<  >ii  the  theory  of  descent  with  modification,  the  jrreat 
law  of  the  lonjrendurinjT,  hut  not  immut^ahle,  succession 
of  the  name  types  within  the  same  areas,  is  at  once 
explained  ;  for  the  inhahitants  of  each  <|uarter  of  the 
world  will  ohviously  tend  to  leave  in  that  quarter 
durin-  the  next  succeedinjf  period  of  time,  closely 
allied  thouifh  in  some  decree  modified  descetidants.  If 
the  inhahitants  of  one  continent  formerly  differed 
jrreatly  from  those  of  anotlier  continent,  so'will  their 
modified  lescendants  still  differ  in  nearly  the  same 
manner  and  deijree.  But  af^er  very  loiiff  intervals 
ot  time  and  after  trreat  tfeo-raphiwil  changes,  permit- 
tintr  much  inter-miirration,  the  feehler  will  yiehi 
to  the  more  dominant  forms,  and  there  will  l,e'  no- 
tiurii:  inmiutahle  in  the  laws  of  pas-t  and  present  di^- 
trihulion. 

It  may  l»e  aske<l  in  ridicule,  whether  I  suppose  that 
tlie  mejratherium  and  other  allied  huije  monsters  live 
left  hehind  them  in  South  America,  the  sloth, armadino, 
and  ariteater,  an  their  deirencrate  «lescendants.  This 
cannot  for  an  instant  he  admitted.     'Ihese  hu^-e  animah. 


have  heoome  whiiUv  ^ vH'-'f 
Hut   in  the   caves  'of   Itra/i'l.  t' 


1,.,,._  !..j\ 


o  {>n)g-f-ny, 


lere  are   many  extinct 


species  which  are  closely  allied   in  size  and'in  otl 


ler 


aoo 


ON    TFIK   ()IU<;iN    OF   SPK(  IKS 


:^ 


rliaracterw  to  tlie  sj»ooios  still  li\  ins;  in  Souiii  Anierica  ; 
and  «i«»mc  of  tlu'^o  tos«;ils  may  Im>  tlin  artiial  |ir(ii:t'iiitorH 
nt  liviiiiT  ^{>^^it>s.  It  nui-t  not  l>«*  forL'ottrri  that,  nti  my 
'.  Iienrv,  all  th«»  •.|n»ri('>*  f»l  the  sam<'irtMiu>*  have  <i('st<'riile<l 
from  som«'  uiu-  <{irii<->  ;  ««i»  that  if  Hix  irt'iiera,  t-arii 
liaviiiL'  t'iu'ht  <]>ecifs,  h«'  found  iii  otic  ifooloL'nal  forma 
tion,  aiul  in  thf  next  rtUiTCfilinff  '"ormalinn  there  he  six 
othfr  allieil  or  ropn'M'ntative  jrenera  with  th<-  -^amH 
tiutiilHT  of  >-[ii'fic»,  tlirti  wo  may  <  (iii<liiile  that  on!'.- 
iirii'  >.[»»Mii'-i  of  e  II  h  of  tlie  six  ohitT  L'^eiiera  lia-*  left 
iii(Mii:ic<l  (le-icentlanfs,  conxtitiitiiiLr  thf  sjv  new  >jcnera. 
Ttii'  other  ^eM-n  «|>etie>i  ot  the  niil  i^t'iiera  hive  all 
liied  (lilt  ami  liave  left  no  [uoL'eny.  Or.  whit  h  would 
nnihiMv  hf  a  far  cnmimuier  ca-e,  two  or  three  '.jieei*  > 
of  two  or  tliH'e  aloiu>  «if  the  six  older  ireiiera  will  hav.* 
hfcii  th»'  I'irents  of  the  six  new  ::enera  ;  the  other  old 
siteties  ami  the  otlicr  whole  old  treiiera  liavinir  U'come 
iitterlv  extinct.  In  failiiiL''  orders,  viitli  the  ^ein'ra  and 
s|M'(ies  deerea-^in:;  in  numliers,  as  apparently  is  the  »as«' 
of  the  Kdentata  of  South  .\meric;i,  still  fewer  trencn* 
aful  spei  ies  will  h; iVe   left  modii'ed  hlood  descendants. 

Siuiiiiiiinf  lit'  thr  jirrrtulnii)  iiitd  prfxfut  i 'tutjiti-rx. —  I 
have  attemjited  to  show  that  the  jreoloirieal  record  in 
extremely  impt'rfe<t  ;  that  «)nly  a  small  portion  (d  the 
<;lol>t'  lias  heen  jreoloL'ically  exploreil  with  eaie;  that 
only  certain  classes  of  oriranic  heiriirs  have  heen  lartrely 
preserved  in  a  fossil  state;  that  the  numher  hoth  of 
specimeMs  and  of  specie-i,  preserved  in  our  museums,  is 
ahsolutely  as  nothing  compared  with  the  incalculahle 
nund)er  of  treneratioiis  which  must  have  pa<sfti  away 
I'veti  duriii;:  a  sinirle  formation;  that,  ouniir  to  sul>- 
sideiicp  U'in:,'  neeessiiry  for  t^he  ac<'umulation  of 
fossilifcrous  deposits  thick  enou^'h  to  re.>-i>-t  future 
degradation,  enormous  intervals  i.f  time  have  elap-ed 
hetween  the  surressive  formations  ;  that  there  has  prcd)- 
ahlv    Uhti    more    extinction    durint;    the    periods    of 

elevation,  and   durintr  the  latter  the  record  will   have 
l>een  lexist  perfectly  kept  ;  that  each  siiiirle  formation 


tiK(>L(K;i(  AL   Sl(  (  KSMON 


tVYT 


»c.^  net  luM'u  roiitinijiiii^ly  (lepoHitiMl  ;  tli.it  tho  diir.itidri 
i.t  »>,i.h  fnrinatinii  m,  perhaps,  sln-rt  inrii[Miro<l  with  th« 
av<T:u:i'  ilumtHMi  of  »<pffifif  tonns  ;  that  miirratioti  h-i* 
I'laytMl  ail  irnport-iiit  prirt  iti  the  first  ,ipp.>ar;iii.-.>  of  nrw 
•ornis  in  any  ouo  arci  and  loritiatKiii  ;  tli.it  widely 
'iiriirintf  Mpi'cu'H  are  thfwe  which  h:ivi>  v.irii'<l  rnrwt,  ari>l 
la-p  ottt'iH'st  ifiveti  ris.  to  iii>w  sjn'iir.s  ;  .iid  tli.vt  v.irif- 
?:!••*  hav»^  at  first  «»(tt'ii  h«'ori  UmmI.  All  these  catisc" 
faketi  conjointly,  must  li;i\.'  ten»itMl  to  make  the  tree 
I  i_n.al  record  extremely  imperfect,  and  will  to  a  !ar:;e 
extent  explain  why  wp  do  not.  find  interminahle  varie 
t:rs.  connectinjf  totreth.-r  all  the  extiiid  and  exi-tin  • 
fill!-;  of  life  hy  the  fin«'st  eradiiated  stt!'-. 

He    who    reieits    tii»'.e   viewi   on    the    nature  of  the 
/. .  hcMcal  record,  will  ri::htly  ren-ct  my  whide  theory. 
I  or  he  may  ask  in  vain  «hereare  liie  nwmherle^s  tra.i 
-  iiiiiial  link-*  winch  must  formerly  have  connected  t   e 

•  li-'elr  allied  or  represpnUitive  species,  found  in  ti  -• 
se>  eral  stiire«  of  the  same  ijreat  formation.  I  le  may  di-«- 
i-eiieve  in  the  enormouM  intervals  of  time  wh  .-h  have 
el.ijisod  hetween  our  ronsecutive  form.itions  ;  he  may 
overlook  how  important  a  part  mi:,^ration  must  have 
i'!i\ed,  when  the  torrn.itions  of  any  one  ereat  rc«-ion 
aione,  as  tliat  of  Kiirope,  are  considered  ;  he  nia> 
liTire  the  apparent,  but  often  falsely  a|>parent,  sudden 

•  omin-r  in  of  whole  jrroups  of  s|»ecies.  He  may  ask 
^  iiere  are  the  remains  of  those  infinitely  numerous 
orH'anisms  which  must  have  existed  huuf  hetore  the 
■Tst  hc<l  of  the  Silurian  syst»rm  was  dejxisited  ;  I  can 
iMswer  this  latter  que.stion  only  hypotlu  ticaliy,  hy  say- 
iii:r  that  as  far  as  we  vau  see,  where  our  oceans  uow 
extend  they  have  for  an  enormous  period  extended,  and 
v*tiereour  osi-illatiinr  continents  now  stand  thev  haM- 
stood  ever  since  the  Silurian  etmrh  ;  hut  that  lon^' 
t'cfore  that  period,  the  world  may  h.i\e  presented  » 
«n  illv  liitferent  aspect  ;  and  that  the  older  continents, 
forrneii  of  formations  older  than  any  krutwn  to  us,  mr.y 
nit<^  ail   "lie   iu  a  melamorpiio.sed  coiiditiiu!,  or    may  iic 


t>nried  under  the  oce^n. 

J'avsinc   from  thes«?  diffiriilties.   all   the   other 


Tej 


:«»« 


«'N    I  UK       .>i(;iN   OF   yi'KMF.s 


I 


1^5 


le.'iiliii;r  t;»rN  in  p.i!i4>oiit(»I'»iry  pet-m  to  ino  dimply  i" 
fnlliiw  oil  llir"  tlnM>rv  of  do-riMit  with  moditicat  on 
throMi^h  natural  hrh'ction.  We  «'ari  thuH  undiTitAiid 
how  it  if»  tlial  lu'w  >«jii«rip«  rom»»  in  «low|y  nnd  mirres- 
Hivply  ;  how  ».|)oci«w  of  fiitffrrrit  rl;ixsos  do  not  iiprps- 
K.irilv  ch.itiL'**  to^rt'thiT,  or  .it  the  samp  rate,  or  in  the 
-  line  (iet'r«'i'  ;  yet  in  the  lonff  run  that  all  underiro 
fiio(lifi(Mt  i"ii  to  "Mine  pxfiMit.  Thp  t'xtin<'lif>n  of  old 
foriiix  is  th»'  almost  inevitahlo  coii'^eijuenre  of  tlip  |»ro 
dui-tion  of  new  forms.  W't^  r.iu  iinder«tand  why  wlon 
a  s[ifvie«  hast  tnuo  disappeared  it  never  reappears. 
<Jroiips  (if  Hpecie-  inrrease  in  numU>rH  slowly,  and 
endure  for  une<nial  periods  of  time  ;  for  the  proccw*  of 
modi;!'  ation  in  neceHnarily  slow,  and  dejiendt  on  manv 
I'OMipU'x  rontinjfencies.  ITie  dominant  (5j>ecie8  of  ti<e 
larjrer  dominant  groups  tend  to  leave  many  modified 
desreudantH,  and  thus  new  suh-^roups  and  (froups  are 
t'ornHMl.  Ah  these  are  formed,  the  s|>eiies  of  the  les- 
vjjforoiiH  frroup-i,  from  their  inferiority  inherited  froni  a 
••oinmon  pro.rfnitor,  tend  to  become  extinct  together, 
and  to  lea\  r  no  modified  offspring  on  the  face  of  tlie 
earth.  Hut  the  utter  eitinrtion  of  a  whole  irroup  of 
».j>eries  mav  often  i»e  a  very  slow  process,  from  tiie  sur- 
vival of  a  ii'^  descendants,  linperiinr  in  protected  and 
isolatefl  siluatioiii.  W'lien  a  jrroup  has  once  who.' ,  dis- 
ap]>eared,  it  does  not  reappear;  f(»r  the  link  of  genera- 
tion has  heen  hroken. 

We  can  understand  how  the  spreadinjf  of  the  domi- 
nant forms  of  life,  which  are  tho<e  that  oftenest  vary, 
will  in  the  lontj  run  tend  to  people  the  world  with 
allied,  hut  modified,  descendants  ;  and  tliese  will  eener- 
allv  succeed  in  takinir  the  places  of  tlu^e  groups  of 
Rf)ecies  which  are  their  inferiori  in  the  strug'jfle  for 
existence.  HcJice,  atU'r  lois!;  intervals  of  time,  tlie 
productions  of  the  world  will  ajipear  to  have  chanffed 
<imult;ineously. 

\\e  can   understand  how  it  is  that  all  the  forms  uf 

iiro,     .iriCCiii.     .iliU     rcilT*;cj     i::..r*i*     i**j^cL.,t  .     v;:;c     ^.a..u 

Bystcin  ;  for  all  are  connected  hy  ireneration.      We  can 
underKtii.d,  from  the  continued  ti'iidency  to  diverireui  e 


(iKOUxiK  AL  8L(:(  FUSION 


MW 


•li 


anuh'r,  v.  1 


th 


e  more  aririeut  a  form  i-,  the 


nuire. 
atirieut 


il  i."'!i»Tally  ditf^TH  from  thove  now  li  •  ug.  W  h 
aii.i  fxtirut  formt  ut\vJi  tend  to  fih  up  t.ijm  Ih'Iwwm 
t'ii»',ruf  lornix,  HometiiiijH  lileiidinjr  two  ^roiij<>4  prt^ 
N  ioii  il  y  ilasri«-«l  AS  distinct  into  one ;  but  more  rodirnonly 
niih  hriiitfiTitr  them  a  little  closer  together.  The  more 
nil  I'tit  a  form  in,  th««  more  oflt^n,  afiparentiy,  it  dirt- 
pi, i..-.  charii  terH  in  some  decree  intermediate  l^etweon 
■rriHipK  now  di^ti/ict  ;  for  Die  more  .-uiiient  a  fjrin  in, 
•!.c  more  nearly  it  will  lie  related  to,  and  con-«e<iue'itly 
re-  iiil>lp,  tJM^  comrimii  [)ro<:f>n:tor  of  trroupi*,  since   U'- 

■  uiiie  wideh  diver^renl.  Kxtinct  forms  are  sel.lnin 
"lireetly  interme<liatt«  between  existijitr  form-*  ;   but  are 

iiterniediate  only  by  a  lonjf  and  circuitous  cour-c 
■iiroujfh  many  extinct  and  \ery  different  fomiH.  We 
can  clearly  see  why  the  or^pinic  remains  of  close!, 
itiii-^ei'utive  formationn  are  more  cbwely  allii-d 
lo  e^irh  other,  tlian  are  those  of  remote  formation -4  , 
:>>r     LJ.e    forms    are     moro    closely      linked     lo;:ether 

y  ;,'eneratiou  :  we  can  clearly  «e«»  why  the  remaino 
»t  an  intermediate  formation  are  intermediate  in 
'■h.iracier, 

1  be    inhabitant."    of   each    succes  ivp    j»«riod    in    tue 

■  ■  rid's  history  have  beaten  their  i)rede<e.s«orii  in  thr 
r.ue  for  iife,  and  are,  in  so  far,  lii4;iM-r  in  the  scale  of 
ii.iture;  and  this  may  account  for  tliat  vaifue  vet  iil- 

Icniied   sentiment,  felt   by  many   palieontolo-'ists,  that 

oru'anisiition  on  the  whole  has  pro^re8se<l.  If  it  should 
ficre.ifter  be  proved  that  ancient  animals  resemble 
*-■>  .1  certain  extent  the  embr\o«  of  more  recent 
njiimals  of  the  same  class,  the  f-\ci  will  be  intelli_'ible. 

liio  t<uccesHion  of  the  siiiiie  tviH'^  of  structure  within 
tbi!  same  areas  durinjf  the  Lter  frpolot'iciil  jw-riodi 
.  e.ises  to  lie   mysterious,   and   is   simply   expUmied    by 

'  tieritaiice. 

If  then  the  ^eolo^ieal  record  lje  as  imj>erfect  as  1 
believe  it  to  be,  an.l  it  may  at  least  be  asserted  that 
liie  It-curd  cannot  bo  pro\e<i  t(»  Ik?  much  nuire  perfect, 
the  main  objections  to  the  theory  of  natural  s«-lectiou 
'•■      Toatly  ditiiini«h('<l    or   (ii-i;ip|.ear       <  Mi    th*-     aher 


l^K 


310 


ON    rHK    OIIKJIN    OF    S|>K(  IKh 


baml.  .'ill  tlio  cliiof  laws  of  j)aIrt'ou'.<)lo^v  jilamly  ^ro- 
claim,  as  it  neeins  to  me.  that  ;i»ffi»'s  have  l^***!!  pro- 
durftd  liy  oniiiiary  iri'iu'rition  :  old  fornix  liavinjr  iM-en 
8Uji|>'aiit»'d  by  new  and  improved  forms  of  l.fe,  pro- 
duieci  !iy  the  laws  of  variation  still  a*  tirnf  ar<i,.nd  ua, 
and  pre-fived  by  Natural  N'loctitm. 


•i 

» 

i    - 

::4 

lO- 

ro- 

•en 
ro- 


CIIAl'ILR    X! 


';K(HiIlAJ»UICAL    |i:>TKIHri  lu.S 


P7'-ieiitci'.»tri!<uti'>niamic.t  bo  an-nui.t.-d  ("Thy  ditTen  H'  e»  In  ii1i)m  si 
C')nli!i'>n»— liiip' rUiice  r,t  tiarritra     Attiiiity  uf  it,'  iiri"luti'  ii 
■tt  iiit  s.ime  loiitiiuMit   -Cetitrtavf  >nutioii-    Mtai;.i  >if  ili.«|"  t  ^ai 
hj  UidU'/f*  ■  t  rliiuate  and  ■  'f  the  lev. !  ■  f  lUv  Und.  nu>i  by  ■  ■<  ■  ;i-i'  .iial 
!>  eaiis  -Inspcrsalcluniip'  tho  Glacial  iKTiod  co-cxU'nsive  wiUi  thu 

Ln  coiisiiierinjf  llio  <listr  hution  of  ortraiiic  heiiitrs  over 
'ho  tiu-e  i:f  the  trldbe,  the  first  trreat  fact  which  htriki-jj 
■IS  i^,  that  iH'itlier  the  similarity  nor  the  dissinularit\ 
of  tlio  inhahitaiits  oi  various  retfions  ran  he  iu  rountcd 
for  hy  tlieir  cliniatal  and  otiier  physical  con(litit)'is.  <  )r 
late,  almost  every  author  who  has  studied  the  su});t'«'t 
lias  comt*  to  this  conclusion.  The  case  of  Ariiciica 
»h)nc  would  almost  suthce  to  prove  its  truth  :  lur  if  we 
exclude  the  nortlieru  parts  where  the  circumsolar  land 
'.*  ahiio-t  continuous,  all  authors  airree  tliat  one  <i!  the 
rno>t  fundamental  divisions  in  ireo;:rai>iiical  distribu- 
tion is  tliat  Wtween  the  New  and  Old  \V'<irUis  ;  yet 
if  we  travel  over  the  vast  American  co'ilinent,  from 
the  central  parts  of  tlie  1  iiite«i  States  lO  its  extreme 
soutlieru  point,  we  meet  with  the  most  diversified  con- 
ditions ;  the  most  humid  distru-ts,  arid  deserts,  lofty 
mountiins,  crassv  ])lains,  forests,  mar^!;es,  lakes,  ami 
^reat  rivers,  under  almost  every  temperature.      TLcro 


/  »i  J    \ I  • 


CAillltktC      ut 


wliich   cannot  he  paralleled   in   the   New— at  least  rt-" 


pi-e 


V  AH  the  same  s 


pecie.s  jreiierallv  re«j 

;ii 


lire  :  for  it  if 


312 


ON    IflE   ORIGIN   or    SI'E(IKS 


a  tiH.>t  rare  ca-t-  u.  fiii.l  a  ;.ti.u{,  of  or-aniMiis  confined 
tf.;iMy  Miiall  spot,  liavm-  .(.ndition.s  [UTuliar  in  only  a 
; '5'',^  .leirret?;  for  instance,  small  area^  in  tli«  (')ld 
Uoria  couM  !.,.  p.Kiite.l  out  hotter  than  anv  in  the 
New  Wcrl.l,  yet  thoe  are  not  inhabited  \,y  a' peculiar 
fauna  or  llora.  Notvrith.tandintr  this  [.aralleli^m  in  tlie 
cotulitions  of  the  Old  and  New  Worlds,  }„.w  widely 
difieront  arc  their  livirit,'  productions  ! 

in  the  southern  hemisphere,  if  we  compare  lari^H 
tra<ts  of  land  in  Australia.  South  Afru'a,  and  «e>tern 
N>ulh  America,  holwc.-n  latitude.'^  2.V  and  .'IV,  we  Hhall 
fni.i  parti*  extremely  similar  in  all  tlieir  conditions,  yet 
It  w<.uld  not  he  pos>ihle  to  point  out  three  ♦annas  and 
iumiM  more  utterly  dissimilar.  Or  :iirain  we  may  com- 
pare the  productions  of  South  America  south  of  lat 
.';.V  with  tlios,>  nortli  of  ^.r,  which  conse,,„»»ntlv  inhabit 
a  con>.derahly  ditfer-nt  .limate,  and  they  will  he  found 
Hicoinparahly  more  closely  related  to  eaVh  other,  than 
they  are  to  tlie  productions  of  Australia  or  Africa  under 
nearly  tlie  same  climate.  .\naloi_n>us  facts  could  he 
/-nven  witli  re>pect  U,  the  inhatutants  of  the  sea. 

A  second  ^jreat  fact  which  -trike„s  us  in  our  ■■eneral 
review  is,  that  harriers  of  y  kind,  or  ohstacl,.s"to  free 
nn^rration,  are  related  in  a  close  and  imporUmt  manner 
to  the  diiferences  hetween  the  productions  of  yariouh 
remons.  We  see  this  in  the  trreat  difference  of  nearly 
all  tlie  terrestrial  productions  of  the  New  and  Old 
^V  orlds,  excepting  in  the  northern  parts,  where  the 
land  almost  joins,  and  where,  under  a  slightly  diiferent 
climate,  there  miirht  lia\e  heen  tree  miirrati'on  for  the 
northern  temperate  forms,  as  there  now  is  for  the 
strictly  arctic  productio!i^.  We  see  the  same  fact  in 
the  trreat  ditference  hetv*een  the  inhahitants  (.f  Au.^- 
tral;:i,  Africa,  and  South  America  under  the  same  lati- 
tude for  theso  countries  are  almo.st  as  much  isolated 
from  each  other  as  is  pussil  le.  On  ea»h  continent, 
aho,  we  see  the  same  fact  ;  tor  on  the  opposite  sides  of 

......         .,„..         •    •■;:^;:;-.;t,..;-         .  1 1  i  :  ;  J  i  i  Ui  ■'  i  I  -  T  .'i  i  i  if  f  S  ,       Uini         Ul        ^'rOHt 

desertji,  and  sometimee  even  of  lart;o  rivers,  we  tind 
dilierr.it     production.  ;     thou-th    as    mo untaia- chains. 


GEOClRAI'fllCAL    DISTKIBLTION 


;)13 


Ji'mtLs.  etc. ,  are  iu>      i.n  imjiassahle,  or   liktlv  to  have 
einiured  so  lone  as   u\e  oceans  separating,'  tontiiu-nta, 

tie  (iitferenres  are   very   inferior    in   (ietrree   to   tho^e 
rtiaractfristic  of  distinct  continent.*. 

I'lirnin^  to  the  >e:\,  we  find  t}ie  same  law.  .\o  two 
;i;arine  fauna'  are  more  distinct,  with  hardiv  a  tish, 
-!)<11,  or  crah  in  common,  than  tho^e  of  the  eastern 
(lui  western  shores  of  South  and  (eritral  Ameri.a  ;  yet 

iie.-e  ereat  faunas  are  separated  only  hy  the  narrow, 
li'it  impas.s.ihle,  isthmu.s  of  I'anama.  \\'e>t\vard  of  the 
'(,i»res  of  America,  a  wide  space  of  open  ocean  extend.s, 
.vith  not  an  i«-l,irid  as  a  halting-place  for  emi^rrants  ; 
here  we  have  a  harrier  of  anotlier  kind,  and  as  soon  i.i 
'his  is  pa.ssed  we  meet  in  the  ea.stern  i-Land.s  of  the 
I'acitic,  vfith  anotlier  and  totally  dist:ni-t  fauna.  So 
•liat  iiere  three  marine  faunas  raiiye  far  northward  and 
!-(>ulhward,  in  parallel  lines  not  tar  from  each  other, 
under  correspondinir  climates;  hut  from  heiriif  bepa- 
rated  from  cich  other  hy  impassahle  f>arriers,  eithrr 
of  land  or  open  sea,  they  are  wholly  distinct.  '  »n  the 
w-iier  liand,  proceeiiinif  still  further  wt-tw  ird  fron;  the 
•M-iern  islands  of  the  tropical  [tarla  of  tiie  I'acitic.  we 
njcounter  no  impa.ssahle  barriers,  and  we  have  ii  nu- 
ii..ra!)le  ifilands  as  haltinir-places,  or  continuous  coxstii, 
until  after  travellinfj  over  a  hemisphere  we  come  to  thj 
sli.ifo  of  Africa  ;  and  over  this  va.st  space  we  meet  with 
no  well-defined  and  di.stinct  marine  fauna.->.  .\lthouffh 
hardly  one  shell,  crah  or  tisli  is  common  to  tlie  .ihov»- 
riariied  three  approximate  fairia.s  of  Kastern  and  \\'e>tern 
-Xriierica  and  the  eastern  Pacific  islands,  vet  manv  nsii 
ra!,.'-e  from  the  Pacific  into  the  Indian  Ocean,  and  many 
siiclls  are  common  to  the  eastern  islands  of  the  Pacitic 
and  the  eastern  shores  of  Africa,  nn  almo>t  exactly 
iiiipi.site  meridians  of  lonfritude. 

.\  third  jfreat  fact,  partly  included  in  the  foreirt>in<r 
•-latement-s,  is  the  affinity  of  the  [troductions  of  the 
same  continent  or  sea,  thoutrh  the  specien  themselvea 
are  distinct  at  different  points  and  stations.  It  n  a 
Li«  of  the  widest  ^'enerality,  and  every  continent  olfen 
ii;:ianien4i>le    instarices.       Nev«rthele»«    tlie    nat;,ralipt 


Ill 


314 


ON    IHK   OKKJIN    l)J-    Sl'hClES 


ill  I  iM'i'  niT,  tor  iiiHL-iiicc.  from  iii-rtli  to  south  m-ve 
fail>-  to  ii»>  ^tl•li(!k  l)y  t!it'  in:ininT  in  wliich  successive 
cTdiip-  of  iK'intr-,  .-[M't-i'iciUy  di^tiM'  t,  yet  clearly  n- 
la'i'ti,  if|.lir('  f.ich  niiiiT.  IIh  hears  from  clo-iely 
alluMi,  yd  (ii^t.nci  kind-  of  hirils,  notes  nearly  similar, 
fiM'i  "-ees  tlieir  iiest^  -iinilariy  con>trurte<i,  hut  not  quitL* 
al:ke,  uith  e::^->.  coliiii rt'd  in  nearly  the  same  inaiiner. 
'I  lie  jil.tiii-  ne.ir  tlie  >traits  r)f  Maj-clian  aie  mhai'itrti 
hy  lUH'  -jMvie-  nt"  Kli'M  I  American  i-tric)i),  am!  uortli- 
waid  the  plain-"  ot  l.i  Plata  by  aii'.the'  -.[mt  e?,  uf  thi 
<iine  ;  eniis  ;  and  not  hy  a  true  o~*rich  or  tiua,  Iiko 
tho-e  lound  in  Africa  atnl  \u-lralia  undc-  tlie  saiiu" 
latitude,  (hi  tlie~e  ^arui-  plains  of'  I^  I'iata,  we  see 
the  lu^outi  and  hi/iacha,  aiiimal>  havini:  nearly  th'- 
vaiue  h.ilii;-  a<  our  liare-  and  ralihit.s  and  helm  _'i!iir  t"' 
'Jje  ^anie  order  of  Kodents,  hut  tlicy  plainly  di-play 
an  Anieriian  t\]>e  oi'  structure.  We  asrend  tin-  I'dfy 
peaks  of  the  (  ordiiiem  ami  wo  f.nd  an  alpine  -pecie-< 
of  hi/.cacha  ;  we  look  to  the  wit<'r<,  and  we  do  not  find 
the  iie.iver  or  muvk-rat,  hut  the  coypu  and  i.i[i\  i-ara. 
rodents  of  the  .X-iuTican  tvp<'.  iiinumeraine  ntlicr 
ilist  i.i^e^  roiihl  lie  i:iven.  If  we  look  to  the  i>iands  ntf 
tlu'  .\  CI  lean  sliore.  liMv\e\er  m':ili  thev  may  differ  in 
>rP(do';.rai  -truclure,  llie  inhalut.inL-,  though  they  iii.iv 
'>e  all  peculiar  ^pecie>:.  are  e-.'-entially  American.  V\  e 
mav  look  iiack  to  ]'ast  a^M's,  a.s  vhouii  in  the  last 
'  liapter,  and  we  tind  American  tyi)es  then  prevalent 
on  the  .\nierican  continent  and  in  the  American  sea>. 
\\'e  ^ee  in  the^e  facts  some  de»'p  orcanic  hon<l,  pre^ail- 
lUir  throuLfhout  space  and  tinu*.  over  the  same  are.i-.  of 
laud  and  water,  and  inde[)endent  of  their  ptiy-;r;i'  c(ui- 
ditioiis.  Tlie  naturalist  must  feel  little  curiosity,  who 
x  nut  led  to  inijuire  wh.it  thi-^  hond  is. 

I'his  hond,  on  my  theory,  i^  simply  inheritance,  tiiat 
raustf  whicii  alone,  as  far  as  we  positively  know,  pro- 
ducers or;ranisms  (|uite  like,  or,  as  we  see  in  the  cit-^e  of 
varietie.-,  nearly  like  each  other.      Ihe  dissimilarity  of 


to  iiioditication  tlirou^^h  natural  selection,  and  in  a  <|uit« 
•u'l.ird.uate  de.Tee  to  tlie  direct  i.Jluence  of  d'"tTenl 


i  ■&-'{" -'ii'-i 


GEOiMlAl'HK  AL    DISTUIBLTION 


^\5 


physical  conditions.  Tlie  dotrn'e  of  <ii--<ini!larity  will 
'ii'iK»n(l  on  the  migration  of  the  more  dominant  forms 
iJlite  from  one  r»'f.non  into  another  liavintr  t'oen  t'fftMtod 
vith  nutre  or  lex«i  ease,  at  periotls  more  or  U'.ss  romote  ; 

>!'  thf  nature  and  number  of  the  former  immigrants  ; 

-  ,Ani   on   tlieir  action   and    reaction,  in   tlieir  mutual 

stniL'>,'i('s  fur  life;     the  rehition  of  ortranism  to  orj^aiiKm 

heintr.  a-  I  have  already  often  remarked,  the  most  im- 

Iiortaiit  lit  all   relations.      Thus  tlie  hiL'h  inij'ortaiwe  of 

"'larriiTH   comes  into   jday    by  checknii:   mit{ration;    a- 

ioes  time  for  the  slow  process  of  modification  thrMui:!i 

'latural  selection.      Widely-raiiirinif  sjK'cies,  ahoumiiny 

.11  indivjilualrt,  which  have  already  triumpln  il  over  man> 

mnpetitors   in  their  own  widely-€'xtende<l   homes  wib 

'lase  the  best  chance  of  sei/iutr  on  new  phaces,  wlien 

"iiev  spread   into  new  countries.      In  their  new  home 

'Jiev  will   be  exposed   to  new  condilion.-,  and   will   (re 

juently  underjfo  further  modification  and  improvement ; 

lud  thus  thev  will  l>e<'omo  still  further  victorious,  an(1 

will  jirodiice  groups  of  modifuMl  dcscemlanti*.      On  thi.- 

■  rin.  ijde    of    inheritance    with    modification,    we    can 

mderstPiid    how   it   is   that  sectiouH  of  <fenera,   whole 

cencra,  and   oven   families  are   confined    to  the   same 

M-e  i>,  as  is  so  commonly  and  notoriously  the  c^•l^e. 

I  believe,  ;i-s  was  remarked  iu  the  la.-.t  chapter,  in  no 
law  lit  iiecessjiry  development.  .•\>  the  variability  of 
each  spec'ies  i-«  an  independent  property,  and  will  iie 
'aken  advantage  of  by  natural  selection,  only  so  tar  as 
it  profits  the  individual  in  its  coniplo;  strut'trle  for 
life.  'O  the  detrree  of  moditituitiou  m  ditTerent  specie,* 
will  in- no  uniform  quantity.  If,  for  in•^tance,  a  niinibtr 
of 'p.'cies,  which  Ktand  in  direct  competition  svilh  ea<h 
other,  niiiirate  in  a  body  into  a  new  and  aMervv.inin 
iMdated  country,  they  wiil  be  little  liable  to  luiMlificA- 
tion  ;  for  neither  mitrration  nor  i^olatJ0n  in  themsflvet* 
can  do  iiivthinfT.  These  principles  come  into  play  onlv 
t)y  brinjfiny  or^nisms  into  new  relations  with  each  other, 


.  -      1    .  -       .      1  ,_.!.__        !  jU    il     - 

-..•;i;  ;:i  a  io»SM.-f  u;:^rct;  w;Iji  ir.v  m. 


•i 


ditioiu*.      .\d  we  have  seen  in  the  last  diaper  that  >omn 
forms  have  retained  nearly  the  s.ime  character  from  an 


•n«> 


ox   THE   OKKJIN    OF   M'KClt> 


■  *  % 


pi.i»rrmMj-l;.  n-niote  ifeolotrif  .1  ju-rMwl,  ^(.  certaiii  himtirh 
.,..VH  M,)_'-..:fM|  over  v.i'^t  ^pace^,  and  l,;.ve  not  hetoine 
.Tfatly  inodihf.i. 

<>n  tlicso  viows,it  is  «l.viou>,  tiiat  tlie  -t-veral  species 
'i  the  saiijt'  irt-nns,  thoutfli  iiiJial.itiritr  the  mt.st  distint 
MiarterH  of  the  ?Torl.'.  tnu.-t  (>ri;rinallv  have  priut-i-ded 
irmii  the  s;in.f  -our.,-,  jis  they  have  desct'iided  from  the 
xaii.H  protreiiitor.  In  the  caw  of  those  species,  which 
have  under-., rie  duriiijr  wfioje  irwdojfical  perHxIn  hiit 
Jittle  moditicatiuu,  there  i-^  not  niu.h  difficulty  in  lieliev- 
iiitf  '1.  iL  they  may  have  nntrrated  iroTn  ttie  vame  re^^ion  ; 
tor  duriritr  the  vast  pjotfraphic^l  and  dimatal  chau(res 
"h)ch  will  have  8upervene<l  since  ancient  times,  almost 
any  amount  of  miyration  i«  possihle.  l{ut  in  many  other 
c;i.-es,  in  which  we  liave  reason  to  helieve  that  the  8pe<ies 
of  a  penus  nave  heen  prodmed  withui  comparatively 
recent  times,  tliere  is  {.Teat  ditficnlty  on  this  head.  It 
IS  also  obvious  tliat  the  individuals  (if  the  s;ime  species, 
t!iouj,'h  now  inhahitint;  distant  and  isolate.l  retrions,  must 
have  proceeded  from  one  snot,  where  their  parents  were 
iirst  produced  :  for,  h.s  explained  in  the  last  chapter,  it 
IS  incredible  that  individuals  identicallv  the  same  should 
f-v  er  have  l>een  produced  tliroujrh  natural  selection  from 
;i3renta  speciricaliy  distinct. 

We  are  thus  brou^'ht  to  the  question  whu  ii  has  been 
lar-cly  discussed  by  naturali.^t*-,  namely,  whether  species 
have  been  created  at  one  or  more  points  ot  the  earth's 
surface.  I'ndoubtedly  there  are  very  many  ca«efl  of 
extreme  dith.ulty,  in  understandini^  how '  the  same 
species  could  po>sibly  have  migrated  from  some  one 
pouit  to  the  several  distant  and  isolated  mdnts,  where 
newfound.  Neverthele,ss  the  simplicity  of  the  view  that 
each  species  vras  first  produced  within' a  Hin^le  repiou 
.■^iptivat^s  the  mind.  He  who  rejects  it,  rejectx  the 
>>-ru  caiuxi  of  ordinary  ^feneration  with  su!)se.iuent 
miifratioii,  and  c^lis  in  the  agency  of  a  miracle.  It  is 
universally  admitted,  that  in  most  cases  tlie  area  in- 
h..i.iird  by  a  species  is  continuous  ;  and  when  a  plant 
or  animal  inhabits  two  noints  so  dist;int  fmn.  e;»ch 
olh.«r,  or  ^.th   an    intervHl   of  such   a   ,;i.;  .:,     thit  the 


(iFXXiRArHK  AI.   DISTllIBmoN 


.'517 


gj.^co  roul'i  not  \io  easil)  pa^-od  over  by  tniifratioi;,  the 
fact  i~i  j^ven  as  something  fiiiarkahle  aiMi  excpplioiial. 
I'lit'  ivipacitv  'if  mijjTa^''-^  across  tlie  ^ea  is  more  dis- 
tinctly limit«'<l  ill  terrestrial  mammal^,  tlian  |>erhaps  in 
any  other  orfranic  l>cintrs  ;  and,  accordnsfly,  we  fiml  no 
inexplirahle  cai*ftn  of  the  same  mammal  inhabitiriir  "li-^ 
tant  puintx  of  the  w(»rhi.  No  groiniri^t  will  feel  any 
difficulty  in  such  ca«es  am  (treat  liritiiin  having  heori 
formt'rly  united  to  Kurope,  and  cnji>ioi|uently  possessjrur 
tlio  Hame  (juadrup<jds.  lint  if  the  same  '•{►ecics  can 
!m»  produced  at  two  separate  points,  why  do  we  not 
tiud  a  single  mammal  common  to  KurnjK?  and  Auh- 
tralia  or  ^outh  America."  The  conditions  of  life  are 
nearly  the  siirne,  so  that  a  multitude  of  European  aiiiitiaN 
and  plants  have  U'coine  naturali-ed  in  America  and 
Australia  ;  and  gome  of  the  ahorig'inal  plants  are  identi- 
cally the  same  at  these  di-tmt  points  of  the  northern 
and  southern  hemispheres:  Tiie  answer,  a*  I  tielicvc, 
i--.  that  manitnals  have  not  heen  ahle  to  mii;rat*',  whert-a-" 
>;ome  plants,  from  their  varied  means  of  disj)erBal,  have 
micTatcd  across  the  vast  and  broken  interspace.  'Die 
•rreat  and  Htrikinff  influence  which  barriers  of  every  kind 
i^.ive  had  on  distriitiition.  is  ititelli^ible  only  on  tlie  view 
ti  at  the  erreat  majority  of  species  have  Um^tj  produced 
oM  one  side  alone,  and  have  not  been  able  to  mig-nite  to 
tl:"  other  side.  Some  few  families,  many  sub-families, 
very  wiany  genera,  and  a  still  greater  number  of  sections 
of  jfonera  are  confined  to  a  single  reflrion  ;  and  it  has 
l»een  observed  by  several  naturalists,  tliat  the  rr.i  t 
i>atural  (fenera.or  those  trener.i  in  which  the  species  are 
n.Dst  closely  related  to  each  other,  are  trener^Jly  local, 
or  coTifined  to  one  area.  What  a  Htran«-e  anomaly  it 
\^  Mild  })e,  if,  when  coinin^j  one  step  lower  in  the  series, 
*>i  the  individuals  of  the  same  species,  a  directly  oppo- 
site rule  prevailed  ;  .ind  8pecie.s  were  not  loi:al,  but  had 
l»»en  produced  in  two  or  more  distinct  are.is  ! 

Hence  it  seems  to  me,  as  it  haw  to  many  (>tiier 
niturali>ts,  tiiat  the  view  of  each  !«pecie,s  bavinif  b«  er 
produced  in  one  area  alone,  and  liavinj;  sulisetjuentlj 
mii,''ral«>d  from  tliat  areA  a*  far  as  it>»  powers  of  miirrUion 


J. 

4. 


31  n 


ON    IIIK   ORKMN    OK   M-KriF:.** 


I 


%ti'i  mih'iistotife  innlor  past  ami  prf»«f»nt,  roiiditinim  jht- 
./littod,  is  tli»»  nio-.t  jtrohalilp.  '  inlouliftMlly  m.iiiy  <  .«-««»?h 
iMTur,  in  whiili  wp  r.iruiot  explain  how  tlie  saint'  spt'iif^ 
(■ould  have  passed  'Vom  r»ne  point  to  the  other.  l>ul 
the  c-«'"irrap!iical  and  cliinat.tl  «  liati^fes,  which  have 
certainly  occurred  within  recent  L'eolofjical  times,  must 
have  interrupted  or  rendered  discontinuous  th«  for- 
merly oontinMoiM  raiiire  of  many  specie^.  ?»o  that 
ive  are  redncd  to  roiisider  u  liet  her  tiie  exceptions  to 
ontMiuity  of  rantre  are  so  nuxnerous  and  of  so  jrrave  a 
nature,  that  wo  outrht  to  irive  up  the  Iwlief.  reiulered 
prohaitle  liv  eeneral  consideration*,  that  each  specie- 
Isa-'  heen  produced  rt'ithin  one  .ar"ri.  and  has  mi^'rated 
thence  as  far  as  it  cimiM.  It  would  Im»  hopele-.-;ly  lediou« 
to  discusH  all  the  exceptional  «a>es  of  the  same  ^pi-cies, 
no»\  liviiiiT  at  distant  and  separated  points  ;  nor  do  I 
for  a  moment  jiretend  that  any  explanation  could  In.- 
offered  of  t  mv  such  eases.  But  after  some  nreliminary 
remarks,  1  will  discuss  a  fevr  of  the  most  strikiiit  elassas 
of  facts  ;  namely,  the  existence  of  the  same  species  on 
the  summits  of  distant  mounttin-rantjes,  and  at  distant 
points  in  tiie  arctic  and  antarctic  retrions  ;  and  secondly 
(in  the  followinc:  chapter),  the  wide  distribution  of  fresh- 
water productions  ;  and  thirdly,  the  occurreiu  e  of  tiie 
same  terrestrial  vp«>«Mes  on  i-lands  and  on  the  mainland, 
thourrh  separateil  hy  hundred-  of  miles  of  open  seA.  If 
the  existence  of  the  same  species  at  distant  and  isolated 
pointii  of  the  earth's  surface,  can  in  many  instances  he 
expl. lined  on  the  view  of  each  species  having''  mitrratetl 
from  a  sinjfle  hirtliplare  ;  then,  considerintr  our  itrnor- 
aiii  e  with  respect  U)  former  climatal  and  treotrraphical 
ciiaiii^^es  and  various  occasiotial  means  of  transport,  the 
belief  that  this  lias  IwH'n  tho  univer!>il  law,  seems  to  me 
incumparahly  the  safest. 

In  discussing  this  suhject,  we  shall  he  enabled  at  the 
fcame  time  to  consider  a  point  e<iually  important  for  u.-, 
namely,  whether  the  several  distinct  species  of  a  grenus, 
which  on  mv  theory  have  all  descended  from  a  common 
protrenitor,  can  have  mitrrated  (under^oinff  modificatioTi 
duriiii^   Bonio   part  of  their   miffration)  from    tlio   an'.a 


(;K(K;|IAI'HI(  Af.    DIMIUlif  tion 


;ti9 


uitial'ited   liy  their  {irnir«'iiitor.      If  it  i-aii   l>«»  -Iuhtji   Vi 

'.♦>  aliiHot  iii\  ari.'ihly  tin-  r^-c,  tli.it  ;v   rcj-iitii,  nt'  .»liirii 

niD^l   -fits  itih.i'.ijtaiit^  .ire  rlo-.-lv  roIat^Ml  to,  or  lx>li>rig 

■(»  tlif  •i.-inio  ireiitT.i  wift    tlio  »ip»Ti(>-.  ofa  -«•(  ond  r«':.'iu!i, 

'i.i<  prolialil V  rfifivt'd  nt  ^oiiic  furnuT  [i»Titnl  imtni'..T:iiit.-' 

'"rtirn  this  i>tli«>r  roirioii,  my  thfury  will  ho  -tnMiL'tlitMt'd  . 

for    \t>   laii    rli-.irly    iimlprstrintl.    on    the    priin'i[il(»    ■•' 

nHnlitir:it;on,  why  th»*  iiihahitarit'.  <  f  ,i  rciT^on  ^ho'il'l  >iO 

.'latod   to  those  of  aiiofhcr  r«':r:<»M,  wlirii'  <»  it  h:i-    l-t'ii 

-■o.  l\«'il.      A  vohanir  i-land,  for  instamo,  iijdi<':i\>*d  .r.d 

nrnu'd  al  thodi-tuiro  of  ;i  t'«'w  hundreds  of  iii;li'»  fmr-i    \ 

"Mtiiii'ht,  would  jirohatily  n'ceivo  fr4im  it  in  t!n'  >  mi     «> 

'•    time  a  ffw  <u!oni>ts,  and   thoir  dc-cendants,  thou,  li 

nodifipd.  wo'iid  -Mil  }»o  plainly  relaffd  hv  irihoritanr«»  ti. 

;l,"  inhahit-mts  of  tlio  contiiuMit.      '  a-»'-i  of  this  natiir»* 

Tf  rornnion,  and  art-,  as  we  si, ill   hi'mifor  rnoro  full/ 

-•  ••,  iii»'xplirahl(«  on  'lie  thonrv  of  iifh'jtt'iidt'ct  in-atinn 

!  !iis  v\,'\v  of  till'   rrl  ition   <;f  -[mm  us   im   ont-   rt-^ncn    to 

tiiO~«"  111  anntluT,  doc-,   not  dijTfr  rnindi  (l>v  siih^tit  itinjf 

•hi-  ^^nrd  varii-ty  for  sjH'cip<j)  fnrn   that  l.-tplv  adv.mfed 

n  an  itiir»'nious  papfr  !py  Mr.  ^^  .iila»<',in  wliicli  he  I'on- 

Imit's,    that   'every    sppt-jp.s    has   come    into   existence 

(•.'inrideiit  hotli   in   s[  ,ne  atid   time  with   a  j<r»>-«'xi-tinii 

■  i'lsidy  allied  specie*.       And    I   now   know  from  corre- 

s]Hindence,  that  tliis  coincidence  he  attrihiite*  to  trctu-fa- 

iiori  with  modilicatinn. 

I  h"  prtnio'iv  remarks  on  '  sincrl,.  and  mi;!t;j>> 
•■litre-  of  creation'  lio  not  d  t!v  hear  on  amUher 
illii'd  (|iiestioii,  —  namely  •<*  iiether  all  the  individuiil-  ot 
•tie  same  s|K'<-ies  have  desi  eniled  from  a  siriijle  ["ir, 
or  -iritrle  hiTrnaphrodite,  or  whether,  as  some  aii'horx 
'  ippose,  from  many  individuaLs  Kirmiltaneonslv  cre.ited. 
U  itli  those  or;ranic  l>eiiii:=  wliich  never  intercio-s  (if 
-will  exist),  the  speiies,  «m  my  tlieory,  must  ha\e  d«^ 
-'  •Tided  from  a  sticcession  of  improved  varieties,  which 
Alii  never  have  hlerided  with  other  itidiv  idiials  or  vari«^ 
tii's.  hut  w'ill  hrtvg  Buoolnnt.v!  each  other  t  ^o  th..'it.  .'it  tvih 
successive  suuT'^  of  modilication  and  inqirovemeiit.  all 
the  individuals  if  eacl<  variety  will  liavc  dest^endeti  from 
a  si!>;jh^  parent       Hut  \->  ♦be  maio-itv  of  ^-aws,  r-in*^!., 


f'^  nl 


n2o 


ON   THE   ORir.IN   (IF   SPK(  IKS 


s-f^ 


U^%r^ 


m^ 


w  th  -jll  orjr.inixniH  wliicli  hahitually  unite  for  i-acli 
('Till,  or  wl  ich  of't»'ri  iiit«»rcr«HH,  I  l)«>liov»»  that  (linitijf 
tliR  slow  ir.Mfs.s  of  modifnation  the  imlividual-t  of  the 
•  [..xKw  will  have  lK>f>ii  k»'i»t  iM'arly  niiiform  l.y  iuU-r- 
(•r'w«iiitr  ;  so  that  many  in(i:\  iiluain  will  have  cone  on 
"itniiltaiK'oa.^ly  cliaiiirinj;,  and  the  whole  amount  of 
ni'i.lili.  ai:..r:  will  not  havf  heeu  due,  at  earb  ^f.iiff,  to 
<ip.>.  <'nt  from  a  ^irlt'l(•  j>arent.  I'o  ill  nitrate  what  I 
nip.in  :  our  Kii^^lish  nu-o-horsos  dilfcr  slijjhtly  from  the 
hor-eif  of  every  other  hreed  ;  hut  they  do  not  owe  tlu-ir 
difforeiic-e  and  sujMTiority  to  des«-«-nt  from  any  Hintrlp 
I'u  r,  tint  to  . continued  care  in  Ki;le<ting  and  Irainiiitf 
iii.iin   individuals  during  many  ironeration«*. 

i'M'tore  disru-sin^  the  three'  <  l.tssex  of  fartit,  whi.h    I 
have  >elerted  as  presejitiiig  thetrreafest  amount  of  diJJi 
«'Mlty  on   tlif  theory  of  '  si ntrle  centres  of  creation,'    I 
niiihf  s.iv  a  tew  words  on  the  iiMVins  of  dispersal. 

Mfdiix  of  J)i.'t>rr.yaL-  Sir  ( '.  Lyell  and  other  autliors 
h.ive  ahly  treated  this  suhject.  I  can  ^^ive  liere  only 
the  hriefe-t  ai»stract  of  the  more  imporUmt  facts'. 
(  haiitre  of  climate  must  tiave  had  a  powerful  influence 
mi  mitrration  :  a  rc:rion  when  it.s  climate  was  different 
may  have  heen  a  hitrh  road  for  mitrration,  but  now  he 
iiH|i,issahlc;  I  shall,  however,  jiresetitly  have  to  discus* 
this  branch  of  the  subject  iti  some  detail.  (  h.miref" 
of  le^el  in  the  latid  must  also  have  heen  hitfhly  .nfiu- 
ential  :  a  narrow  isthmus  now  sej)arates  two  marine 
fiunas  ;  s,,hmer/e  it,  or  let  it  formerly  have  heen 
siihmer^red.  and  the  two  fauti.as  will  now  J)lond  or  mny 
!'>rmerly  have  blended  :  where  the  sea  now  extends, 
land  may  at  a  former  period  have  connected  islands 
or  posvildy  even  cotitineuts  tofirether,  and  thus  have 
allowed  terrestrial  productiotis  to  pass  frotn  one  to  the 
other.  No  treolotrist  will  dispute  that  irre.it  mutations 
of  level  have  occurred  within  the  period  of  existinif 
oreanisms.  Kdward  I'orbes  insisted  that  all  the  islands 
in  tiie  Atlantic  must  recetitiy  have  Deen  cotniecfed  with 
Kiiroi)e  or  Afric^i,  and  Kurope  likewise  with  America. 
Other  authors  have  thus  hypothetically  Iiridi^n'd   over 


(.KCMJKAi'ffK  Ai.  rusrKiiirnoN 


321 


-  .TV  (M,.ari.  ,-111.1  Ik.v,.  iiiiit-.l  ;.Iin<Kt  .•v,.r\  i,Ii,„l  to 
-n...  maitilan.l.  h  i,„j..,.d  tl...  Hrt'.ini.nts  „M<i  (.y 
»..rt..-s  ;,r«  tn  l.o  tr.Kf.vl,  it  mu^t  I.,.  :i.lM.:tt.-.l  thai 
-.•r  olya  Mu-l.-  |.l.„..l  ..xi.st^  vvhi.l,  iKi.  not  m-.-ntlv 
'■•'■:.  iiint.-.l  to  M..„..  .•niitni.-nt.  TIih  m.-w  ...iIn  t)ir 
<  ■•.'  li.iii  knot  of  til.,  .li^iwrvil  <.tthes.„,ies|)e.i.-<  to  tli.- 
:■  ■••<i  -li-t^iiit  point..  ;iri.i  rrmo.fs  manv  a  .litririiltv 
■•It  to  iIh-  )..-t  of  my  Mid-n.f'iit  «e  :i!«."not  authorisv,! 
'.  .olni.tfin-  M„h  ,.nonno„.  j;,M.^-ntMl,;,..-il  rl.anir.-H 
-.Mmm   t  „.  pf.no.l  of  ,.vi.:i„ir  .p,...„.s.      It  mmtu.  to  me 

•  .It  u,.  I.av..  aKiimlant  evi.leiire  of  trreat  OM-il.'atioi,^  ,., 
•■••>i  in  our  rotiruMMifs;    but    not   of  .url,    v„,t  ••li.ui-.-. 

•  'n.-:r  |.o.,tio,i  atiW  .-xt.Mi.inr,.  a-  to  |,.-.m'  iinitr.l  thin, 
'  -Mn  t(,..  re.Ti.t  i.tTin.i  m  mrU  nth.  r  afnl  !o  tn.. 
-n.Tal  !titprN.-nm;r  o.-raiii--  i.|;u,,|v.  I  frr.-lv  a.imii 
•MM    torrnor    .-M^t.-ri.-,.    „f    ,„anv    i^laiwls.    ri.o.     I.,ine(i 

••■ri-.-.tl,    the    .,>a,   wlii.h    may   havp  ...rv.-.l    ;,„    l.;dti„.r- 

•■   H.-    f,,r  plants  au.l    for   i,i:.nv  anii-ril-    .iunn-   tl.nr 

■     --'■atin:i.      In  f!i.- roral-pro.|Mcmir  o.-ari.  such  ^mv  ,-r 

.     "Il  ar..  now  mark.-.t.  as  1  l.W.ev...  nv  rn.es  of  .-..rai 

.^•oll'.  .tan.lsn,^  ov.-r  th.-rn.        \Vh,.n'..v,.r   >t    is    fullv 

•!»i.tte(  .  as    I    h.-li,.vo   it   w:!!   som.'  d.iv   Im-.  that 


1 


.  '    ^oiin-  ii.i\     iif,  iriar    »mi(i 

-u's  has  pror».,Ml,..l  from  a  sintrle  i.i,thp!a. v,  an.] 
■'_■'[  in  til.-  rour-p  ..f  tin...  ne  know  s.,;.;,.thiin: 
finite  .il.out    th».  ,„.-ans  „f  di^trihut:.,,,.   w,-  .hiU    !,♦- 


'•■!-;l     to    spe.  ul.it.-    wit!,     serur.tv    on     the     „,rm,.r 

'';"'■'""  ••'   '►"■   I'"'.!        Mut   I   ,io  no'    h..!,Hvo  that    ,. 

.    I    -v.-r    f„.    p:„...,|    that    vvithtn    the    n-.-ent     p.-n-.l 

•■•nf.n.'nts    wn.rh    a-    now    .pnte    separate,    hav..    I.,-.,. 

■•■    -■  'iously.  or  almost  ro-,tinuonv! v,  unite.!  with  ea.  Ii 

-•-•r     anil    .mm     the    many   exi<t:n-    o.'eanir    whuni, 

•    '■'■•'I    t.i.t..  HI  .iNtrihufion.      .,„  h  as  the  trreat   .li??..r- 

'•■    "1    the    marme    faunas   on    th.-   oj-po^.t,.   .i,lp<   „t 

-.-r    e.,-r.v    eontr.ent.-     the    .-lo.e    relation    of "  the 

'r:arv  inhat.ita!:t>  of  M-v.-ral   lan.L  a,.,!   even  se.u*  to 

'  '•  r  preMTjt  nihahitant.-.     a  certain  -'"  r 


an. ma.,  an.l    ttie  .jepth   of  the   sea,-~th 


'.'ree  of  reiat;(,n 
irii   tli.    'iiM.rii>iitir.ri  of 


.iicli  facts  seem  t. 
tTodiifini 


pse  am 


.  me  oppost.,1  to  the  a/lmiswon  of 


iH  jreoc-raphiral   re\olutio 


other 
'lii-h 


IIS  withiu   liie  rpcetit 


;^. 


■A2J. 


ON     I  UK    (UtKJIN    <»K    >J'K<  IK> 


t"  I,  n-  ;irr  rin  I'^-iUitj'd  on  '■<..  .  ■.  .^  itlv^iih  cii  t. 
tirli"'^  ;iii»l  adiiiitb"'!  iiv  hin  iiiany  '.•ll(»w(r>.  Ihe 
ii.iliiro  .iiid  r»'l;iti\t'  ps  n|iortioii^  ni  tlir  inli.il'ifant^  uf 
'►'■rail  <•  i»latiiN  likrii^c  hci'ii.  to  !iif  ii|ipo~i-ii  U<  tue 
Ix-lift  «<(  tht'ir  fortiHT  <»irititiiiit\  wiili  roritiin'iit.s.  Nor 
iloi's  tlifir  almost  iini\ t'r>all',  oliMuic  ..iiiipo-  lori 
ta\«inr  til'-  ;iiltiii>«»  oi.  that  tlirv  art*  tli--  >vrri  k^  «>• 
■•uiikt't'  roiitiiH'iit- ;  if  tlii'V  li.i'i  i»ri:;i!ial!v  <>.\i-if(|  a» 
tiioiinl.i;ii-r'iriL''i'*'  <'ii  ti.f  I.hhI,  sotii*-  at  li'a>l  ol  tlir 
l^laIl(l-  -^oiild  have  Iu'«mi  t<irtiit'<l,  liki*  ntlit-r  nioiiiifam- 
«i)"iinit-,  (it  trruiiiti',  inctainorphu  M'lii<t»,  oM  fosHJl- 
ifcroi.K  or  otiu-r  ^ui'ii  ro.  k>.  iii-tta<l  o.  coiisi-Liiiir  >>f 
nuTi'  [>]]'.'•*  ot  volc.iuic  iii.ittrr. 

I  iM      '■   1111'*  >av  .1  ti'w   v^oril-   on  m  liat    arc  ca'.Ifil  afi 
(U'lit.ii  I'll  in,,  \in\  wlii.li  iiKM-i-  projii-rly  innrlit  !'o  railc 
o(T.i>'  'till  rin-ari".  ot  (ii-^trilHi'  on.      I  <hall  liiTf  'oiiluit 
iii\-''It'i>  jtlant*      !n  IxitaiiHal  uork-,  thi- or  tliat  jilaii 
is  ht;ii»'<i  lo  Wp  ill  aiiantt'ti    for  wiilc  iii«>t>iiiinat ion  ;   l»u 
tor  trail-port  across  tlii' ^•'a,  tlir  tri'' it»*r  or  U'-s  hinlitir- 
may    Iw   "••ml    to    In'  airno-'    wlioll;.    nuknovn.      I  nlil    I 
trii'd,  with    Mr.    Ii»'rk<'l»'y's  aiii,   a  ft-w  ♦•xporitiu-nts,   ii 
«a.«  not    fvcn    ktiown    ho*  tar  Kfcd-i  ronid  rf>i^t  'lif  in- 
jiirion*  attio'i  oi  !.t»a-wat»*r.      lo  ni\  >.nrp;i<t'  I  found  tha 
uiit  ot' H7  kinds,  <'4  tj<'''riniia'i  d   atti»r  an   itnnicrs  iri   of 
L'!;  da\<,  "nid  a  t«'W  Mirvut"*!  an  iiiiinor-i..n  of    \'<^~  day 
|-"or     >  tur.  rniftiiM''    sakt'     1     cdiirliy    tr:t'd     >-niall    ^<'i>ds, 
williont  tlio  rip-'ilt' or  fruit;  .ind  .'is  all    >!   fiie-e   -cmk 
in  a  f«'«    di\-,    tlu'v  coiiM   not   Ik?  tioat«  d  a- r<»>*s  widi 
>parrv  of  tin-  >im,  vvln'flitT  or  not   tli«'\    '.mtc  .niurcd    li\ 
tli<«  s;ilt-\*,iii>r.      Aflt-rwards   1  tried  .somt-  iar^'»'r  fruitf.. 
tap-iili's.   etc..    and  M)nie  of  these    lioatcd    {<<r  a  lont 
time.     It  is  Midi  kiiowti  what  a  ditferem-r  tlure  is  in  (he 
hiio\  aiicy  of  tT'"'"''!  ''iiid  sciu-oned  liinl»er;  a-id  it  oi-furn-d 
to  ino  that  llood-  ti!';;ht  «;i.sli  do.\n   plant«  or  liramdies, 
and  that  tin  >e  inijj;ht  lie  dried   oii  tin-   hanks,  anil   then 
l>v  a  fresh   rise  in   the  stre-iin   he  na-iifd   into  ihe-ea. 
lience  I  w.is  led  to  dry  >tt'ius  am*  lirmrhes  of 'J  I  jilanU- 

majoritv   sink   <ju!<kly,  hut    soin«'  which   whilst  ^reen 
tlo  ited  tor  a  ver\   *hort   time,  when  dred  tlonted    tnurh 


(.E<H,HAI'HI(  Al.    DIMIIIHI HON 


;<'j;i 


</    :'.rr  ,   lor  .ii-t.in. »',  r:|.4- |i.i/»-i-nii*> -.ink  ; rn iin'il :.i •»•.-, . 
liiit  when  «lrit'(i  tli»«y  (i<i.it.-.l  for  '.»<»  iia>,,;iii(l  .-illrrw.tnU 
^Ifti   plaiif.-l    tlicy   tr«'rtniii,4ti'il  ;      iii'  ;isp.ir;ufUH    |il,iiii 
*itii   rijK'   U'rricv.    flo.itnl    Jur   LM  .lavn,   wiicn  dri.  J   it 
ii»t#'il  for  V,.'>  Ha\>,   nii-i   the  >•«•.  .1-  altiTwarW-   li-mhiii 
'•••I  ;   »lie  riiM"  ^ctvl^  of  Helo-riajlium  sank  iti  tv*o  il.iw 
•lull  (irifil    tlu'\  lii.at.ul    for  ahovo  [nt  (li\-..  arnl   at',  i 
'  i'<l-  i.'fnn.;iat«'(i,         Alti>i:»>t],..r  out   ot    thi'  ;«i  .In.d 
,.laiit>,  1,;    ili.atcd    for   alxivo   :^';i  .lays,    tiid  riornt'  ni    il 
il  fioatj'd  for  a  v»t\  murh  lon^'.T  j..'ri...|.     So  lliat   i-  :  ' 
•iT.I    iTfrmiiiatnl  ail.r  an   iniriuT-i..n   ot   2i;   day-,   ai^i 
i.>^:  plants  v%itliriiM'  iniiKi.iit  not  all  ;tie  ^aIlu•  >•}.♦•<  i,-- 
•i-i  in  tiiL-  forft'oin-.xj.eriiiijMn;  tloalrd,  art»'r  iM-iiicdri.-ii. 
■  r   ilK)ve  J;{  da\-.  as  i'ira.swo  rn  ly  iiiUT  aiiytliiinr  from 
ili.'-i- sraiify  t.nts,  ur   may  .011.  ludi"   that   tli««  ««■,■(!-'. 
,»r>8    plants   of    lus    (ountry    niirlit    !..•    rioatrd    l.y    -.m 
luricnt- duriiiL'  .;;  dayx,  and  would  n-taiti  tln'ir  po'wei  oi 
.  .■rriiiiiai.ou.      In  .'ohnston  ^  IMiysical  Atl.i>,  ;li»'  avjM/n:f 
I  •!«'  of  the  srvcral   Atlantic    viii'-.Mit.s   i-  ;;;{  m;l.'>   pfT 
■:  ••tn   (>oino  ruricnt.-    running   at    the  rat**  «if  tilt  in.ic- 
,  ■  r  dirniy  ;   on  tlii^  averaire,    the    -.•♦■ds    of  ,i,»5   plant.^ 
•  ••'ItinirinL'   to  one  counuy  rniL'lit    'h«   llnat«'<l   ,i<to-s  :'-J  I 
:iiiN'>  of  v,-a  to  anotlier  fountry  ;  and  «  lien  -trandt;«l,  ii 
i'liiwn  to  a  ta\oiiral.U'  sftot  dy  nu  inland  ::al.",  tli.>\  \vouI(i 
.■.•rniinate. 

^uif-t'.ju.-ntlv  to  i.iv  t.\pt  r  incnts,  .M.  Mar't-n-  tr,.-: 
>iiiiiiar  Mill'-,  ,iit  in  a  much  hetler  rnaiinrr,  foi  1  .■ 
i  I  ic,.d  till'  s»'t'«l:'  in  a  1><>V  mi  tin-  ;utual  sea,  so  that  IIm-v 
*rif  al'ernaf»'ly  v.ft  and  exposeii  to  the  air  iiki-  really 
I  iiatini.'  }daii*>.  ]|e  tried  ";»!{  seeds,  ntostlv  di'S-r.-n! 
litiiii  uiiiie;  hut  lie  «-liose  many  lav.e  fruit**  and  Iiktvvi«f 
-.H'ds  irom  j)lant.-  «lijeh  live'iifir  the  sea;  and  tiii» 
■*"uld  have  favoured  tin.  avera^re  lenylh  of  their  liot.i 
!ion  and  of  their  resistance  to  the  injurious  action  ot  t|  ■ 
-alt-water.  On  the  other  hand  he  did  not  previouslv 
dry  the  piaub.  or  hranch.".  witli  *!ic  fruit;  and  ihi-,  a> 
we  have  seen,  would  have  oaii.Hed  some  of  them  to  hH\e 
:      -.  ;ti    :;;;;rri    iuiiti  . .  i  he    lesuil    >*a.s    liiat    j;   of    Jll- 

M-eds   Jli.ated    for  4:.'   day-,,  and    were   then    cap.ilde   o 
iiiinatioii.      Hut   I    do  not  douht  th.it  pl.ints  exposei. 


>  < 


S-H 


ii' ' 


IP.  ■ 


I 


.Ti4  ON     IHK   OUKilN    OF   Si'K(:ih.s 

•  o  th.  vvHv..  wo.1.1  Ilo.it  tor  a  le.s  iMUO  thau  iho^.  pr«> 
;  .  M     rum  vu.lcMt  n.ov.-n.ent   a^  n.  our  »^M-n">  "  ^^ 

'  r.     s  ott.M    lloat.uu'   l.-n.^.-r    than    ih.   s.nall    .. 

l.i,.,.r   iruus  or  triiit  «-oul(i 

:i:r;;j;:ih^.,J>W...n  that  ...h  ,lan:-   ..nera.v  haw- 

'"^;r::'.i:";n:vl casionaiW,ra,.,..rt.llnannt,u. 

,.,  n,.er.      Dnti'  Umt..r  .s  thrown  up  ou  "^'^     ;1;'.'     J 

M  tluw..  in   thf  in'wlst  of   the  widest  u,fau>  .  au.i 

r: r:,"      ^     f   ho     oral-islandK  in  the   I'a.in-.  pro.-ure 

.:f  o;thlir  tools  .d..lvtror;When..:so,dned 

tU..    th.-.e  stones  beinu'  a  valuable  royal   ta.       Id 

•      ♦.   ,,    tir.i    when   irr.'Lni  arlv   ^hajrtMl  ^*tone- 

""  '"•":"■;.    i   in     b^    n    t     of   i'..-S   ;.nall 'pan-ols  at 

l^.;:;;:':;     V.      M.uV.M.-los.Miinthnrinter>t,.e. 

>\    1       1   Aw  m    -  M.  VortVrtlv  tliat    not    a  iKirticle 

.:  „^ ' ' .: „t  i.ir,i-.  »i.."  ii..^"i"i-' ""  ""•  *•"•, ►•""»■""'"* 

-•rv;:;.t,r;::i;rr",:t,:;;;;;.-..tnf^^'-' 

man>  fa.  ts  ;bo^^.^_  ^^^  ^^^^  \i„i.,,;,es  a.-ross  the  ore.u,. 
vi".  nriv  I  think  "^iteiv  :iss,ime  that  un.ler  .u.h  r.r.um- 
lr.:-,heir   rat.  of  .U.h,  would  otYen  U,  .•>  m.le.  an 


GE(H.KAi'HlC  AL   UlSTUIHl  TION         .32.') 


hou 
••slim 
(1 


r  ;  and    some    atitlmrs    have    jrivon    a    tar 


bitrl 


i»'r 


;it*.       I  1 


lave  ii('v< T  -• 


•in  an  ii)-itanct'  of  nutritiou? 


1. 


efds   [lassiiiiT  tlirouirii 


the  int«'>itin(*s  i 


t    a 


hini 


arc; 


1    Heeds  of  fruit  [<;i><   uninjured   ti.routrh  e\«'ii  ♦ 


hut 


.iii."'stiv('  uryatiH  of  a  turkey. 


In  '"lie  <"oiirse  ot  two 


months,  i   j.icke-l   up  in  my  u'.irden  I'J  kin({>i  of  «et'(."^. 
nut  of  the  excrement  of  small   t.ir-ls,  and   these  «.-enu'<i 
j)erf.^<-t,  .in<i  sonu-  of  them,  winch   1  tried,  irermiriated 
i'.ut  the  foilowiiiir  "ai-l  i"  m.'-rf  important  :   the  crop^  <.l 
birds  do  not   ^e.Tete  trH-otric  juire,  .iiid   do  not   ni   tlio 
least  injure,   as   1    know   l-y   tiial,   the    tr«'rminaii<.n  ot 
..(■ods  :   !iow  after  a  iiird  ha>  found  and  de\t»ured  a  lars.'- 
-upplv  of  food,  It  is  positively  as-erted  that  all  the  trr.m. 
.in  not  |>aK«  into  the  jfizzard   for   1-  or  even    IH   hoiir-. 
K  bird    in    this  interval    mitrlit   easily  he   hlown   t<.  tin- 
distance  of  60<)  niile*^,  and   hawks  are  known   to  loo!^ 
out  forUre<l  birds,  an<l  the  <onlent-  of  their  torn  crop- 
mitrht  tiius  readily  tret  scattered.     .Mr.  Hrent  inform>  u.. 
•hat  a  friend  of  bis  had  U)  ^ive  up  flyintr  earrier-juceon- 
from  Iranre  to  Kn^l.-uid,  as  the  hawks  on  the  K;ic!  -h 
.oa.st  dwtrovwi  ho  many  on  tlieir  arrival,     ^ome  hawk- 
md   owln  bolt  their  prey   whole,  and  after  an  interval 
of  from  t»«-lve  to  twenty  liours,  distforce  |>ellets,  win.  h, 
,is    !   know    from  experimentfl   made  in  the  Zooloi.n.a': 
(iardens,  include  seeds  capa;dp  of  cermination.      Sttrnf 
-^•(uW  of  the  oat,   wheat,  millet,  cJinary,  hemp,  clover. 
Mid  t»eet  irerm-nated  after  having   tteen  from  twelve  to 
•Hcnty-one  hours  in  tiie  stomachs  of  ditferent  birds  o) 
l.rey  ;  «nd   two   se^nls  of  l)e*'t  ^ew  after  having:  i>e<M, 
•hu-  retained  for  two  days  and  fourteen  hours.     Kroh 
vvit^T   fi.sh,  1   find,   eat  B*^i-  of  many  land   and    watc 
ldant.s  :  tish  are  fre<|ueutly  devoure<l  by  birds,  and  tliii« 
•he  seeds  mieht  l>e  transq)orUHl  trom  pla<-e  \o  pla<e       ' 
tnrted  many  kuids  of  Heeds  into   the  st^inno  hs  ot   <ie.i.! 
."i4i.  and  then  jjave  their  bodie,i  'o  tishintr-ea^'les,  storks, 
and    pelicans;   tlie--c    birds  after  an   in'erval   of  rianv 
iiours,  either   reje^-ted    the  m  eds  in  |>elletj<  or  p.i-«'.' 
th.in  in  their  excrement,    and   several  of  the^.-   ~»ed- 
retained  their  jxiwer  ot    jrerminati«»n.     (  erUui  .mmjUb, 
loviever,  were  alway';  killed  by  tliis  prorei-!i. 


1  n 


I 


Ifl 


fi 


If  if 


I 


ir 


3v.-  i»N     IHK    OllKilN    OF    hPKCIF> 

\llhoii«l'   the  Kr.iks  niiil    fe«'t  .>i   h:r,ls  arc  u'<-Mer.ill> 
nuit-   .-lenM.  I   c.in   -hn*  thnt  eartli  w.-n.,-limes  ;ulh.Tes 
to  them  :   m.  on.'  i.^faiic-  I  removed  twenty-two  irnmis 
,.l  .irv  ar-.Uao-o.is   .Mrtii  from  one  foot  of  a  j>.'irtr..i^'e, 
an.i  i„  thisenrth  th.^n-  ua8   a  pel.l.le  .|iuto  as  lartr.' as 
llH,  so,  (i  of  a  vetch       TIhh  see<l>  mi-l.t  oora^:orial!>  be 
truisporte.1  to  irreat  (li>tancPH  ;  for  inanv  facts  comI..  be 
uiven  -l.ouinjT  tlwit    soil  almost  everywhere  is  (-.larfre. 
;.  ith   M.-e'ls.      Hellect    for  a  tn-'ineiit  nn  the  millions  o. 
quails  which  annuallv  cross  the  Me-literrauean  .   ui.l  cai« 
we  .l..iiht  thai  the  earth  adheriii?  to  their  feel  vfou  1.1 
snmetimeM  include  a  few  minute  seeds .-      IJiit   i   -ha, 
prcsen'lv  hav.' to  recur  to  this  suhject. 

\s  iceher-"*  are   known  to  he  sometimes  .oaded  v\!th 
^.-.rth  and   stones,  and   haNe  even  carried    t.r.ishwood, 
i.ones.  an<l  the  ne^t  of  a  iaiid-hird,  i  can  hardly. louht 
Ihitthcvmu.t'.cca^ionallv  h-ve  trar^^ported  se.-.Utron. 
«,„ei.art  to  another  of  the  arctic  and  antarctic  re- ons^^ 
as  .'i  '^este<l  hv  l>v»'ll  ;  and    durint;  the  Glac-al   |.erio  i 
fron.  one  i.arl  .'.f  the  now  temperate  re^'ions  to  an..lhcr. 
In   !lie    \/ores,  from   the  lar-_'e  number  of  the  species 
ot  i.iant.s  comm:.n   to   i:urope,  in  omparison   w,th   the 
i.iant.s  of  other  oceanic  islands  nearer  to  the  mainlanu 
uid  (a.s  remarked  bv  Mr.  II.  (•.\\'at.son)  from  the  some 
vhtMiorthern  character  nf  the  flora  in  comparison  witb 
•i.e  latitude,   1   susjuvted   that  those  islan-ls  had    Wei^ 
.  -irtiv  sto,ked  bv    ice-borne  seeds,   dunriir  tlic  Uiacial 
;.„..ch.    At  mv  request  SirC.  Lyell  wrote  to  .M.  HartuiiK 
u,  inquire  whether    I.e  had    observed   v.rratic  boulders 
.,,1  thcM^  Island-.,  and   iie  answered   that   ho   had   found 
i,rv   fnurmeiits  of  -rauite  and  other  rocks,  wh:ch  do 
unr.Mcur  in  the  ;.nhipelat:o.      Hen-e  we  m.ay   <afely 
inier  that  iceber^^s  fornerlv  landed  their  rocky  burthens 
on  the  chores  of  ihe>e  mid-oceau  i-iand-.  and  it  is  at 
least  possible  that  they  may  have  hro,i-at  thither  the 
-iii>d-i  of  northern  plants. 

(•.,..o;.i„ni„„-  that  til.'  several  above  means  of  traiiK- 
port,'  and  that  several  other  means,  which  witliout 
doubt  remain  to  l>e  discovered,  have  Wen  in  act.oii 
V    ar  after  vear    for  renturi.-  and  l.-us  of  thousand.s  of 


GEOGRAPHICAL   DISTRIBUTION 


32i 


\t'v.-n,  it  would   I    think   l)e  a  marvelloui  fact  if  many 

ilan'a  had  not  thus  become  widely  tran-|>orted.      IlieM*' 

ii»ian««  of  trail-port  are  sometimes  called  accirlental,  but 

hi>»  ix  iii)t  strirtly  corrert  :    the  currents  of  the  nea  are 

.ot  aaiiU'iital.  nor  is  the  direction  of  prevalent  jfaies 

if  wiiKt.       if    should    be   observed  that    scarcely    any 

iieaiiH  (if  transport  would  carry  >eeds    for   very  KT<*at 

iistant«<i  ;  for  seeds  do  not  retain  tlieir  vitality  w^hen 

•V  posed   for  a  irr»'at  leiiirth  of  time  to  the  action  of  sea- 

AJiter;  nor  could  they  be  lonj?  carried  in  the  crops  or 

,iitefttii,c-iof  bird><.   'Hie-e  means,  however,  would  sufhce 

'Mr  occasional     transport    acrosH    tracts    of    sea    some 

i  iiiln'd  miles   in   breadth,  or  from  island  t<»  island,  or 

•r((m  a  continent  toa  nei^hhouriiitf  '>laiid.  but  not  from 

lie  di-tant  continent  to  another.     Hm-  floras  of  distant 

ontimuts  would  not  by   -uch   means  become  mintrled 

II  any  ^rreat  decree;     but   would    remain   as  di-;inct 

i-i  w»«  now   see  them  to   be.     'Hie  currents,  from  their 

»ur-e,  would  never  brin?  seeds  from    .Ndrth  America 

•  Britain,  thoujfh  they  mitrht  and  (..)  bring  seeds 
.mil  th«»  \\'e'-t  Indies  to  our  western  shores,  where, 
:  not  killed  bv  so  lontr  an  immersion  in  salt-water, 
ru'V  could  not  endure  our  climate.  Almost  every 
•mV,    one    or    two    laud -birds    are  blown    across    the 

»l.o!e  .Atlantic  Ocean,  from  North  America  to  the 
*t'-tern  shores  of  Ireland  and  Kiifrland  ;  but  seeds 
11  lid  l>e  transported  by  these  wanderers  (uily  by  one 
iipans.  namely,  in  dirt  stnkitjjf  to  their  feet,  which 
-  m  itself  a  rare  mci.lent.  Kven  in  this  case,  how 
-rnaii  would  the  chaiu  e  1)6  of  a  seed  falliiii,'  on  favour- 
Me  soil,  and  coiiiin?  to  maturity!  But  it  would  be 
.    irreat  error  to  arirue  that  because  a   well -stocked 

•  i.ti,  like  (Ireat  Hnlain,  has  not,  as  fa.'  as  is  known 
uid  it  would   be  verv  difficult  to  prove  this),  received 

vithin  the  la.st  few  c»Mituries,  throuirh  occasional  means 
•  transport,  immiirrants  from  Kiiroi>e  or  any  other 
itinent,  that  a  poorly-stocked  island,  thoutrh  standint: 
.,.r«  rairi'.ite  froTp.  tht'  mainland,  would  not  receive 
.ilouists  by  similar  means.  I  do  not  doubt  that  out  of 
'^'  ntv  -ced-i  or  r'nimals  transported  to  an  island,  even 


£i^-^'ZiM^.i'i^'- 


^. 


....     ^^^rs^i^^^ 


!  i 


S2» 


ON    THK   ORfr.IN   OF   SPECIES 


,f  f&T  loss  w<»ll-Ht()rk.(i  Uiaii  linuiiu,  grrinely  wnrf  ihan 
one  would  \>f.  «••  wfll  titttvl  to  its  ih-w  homp.  a«  to 
beiome  Il.•lturali^.•(l.  Hut  this,  a».  it  hwdh  t<»  rre,  i» 
no  vali(i  ar^runient  aiiaiiist  what  wouM  1h>  effocU'd  hv 
ocrasictnal  tueariK  of  trans^Kirt,  duriiijf  the  loiitr  I:H>«*e  "^ 
fc(iIoai<-.il  tiirip,  whiNt  an  islatid  wa*-  h«'in^  ■iplif^vfd 
ami  turmrd,  ai.d  befort"  it  h.iii  l>o<-nmp  fully  sunrkrd 
with  '.iihaiiitaut^s.  <  >n  aimont  hare  land,  witli  !♦•*  or  im 
<iehtru<t)v»»  iiij-fcts  or  hirris  liviufir  there,  n.-arlr  e\ery 
»e«'(l,  wh:<  h  cliaucefl  lo  .irtive,  if  nited  tor  ilie  clirnau-, 
WDiiliI  We  nure  Xi>  jrermiuato  .iiid  survive. 


[hM>rr*(il  dtirMiij  ttif  iilnriiil  prrunt.       The  iden':'v  of 
many  |'!aiit>  and  aiiima!-.  on  inouiiUiiii-suiiinm.', -'Miar- 
ateii  iVniii  e;ii  ii  other  hv  liuiidred<  of  mile-;  of  l(i\»latid:>. 
\Tlicif    thfl    Alfiiue   -.iieiies   could    not    |»o>^silily   e\i-:t,    i*- 
oiie   ot    tlie    nio>.t    striking    tasox   known   of    »!<;   hanie 
NJ.«•.■ie^   livirit;  at  di>Uii'.  jiointH,  witiioiit  the  a|>pareiit 
j.o'im'.ilit  V   of  their   h.iviiiL'   mitrrated   from    one  to  thn 
other.      It  is  indeed  a  reinarkahle  fa<t  to  ~<»e  ho  ma:i\ 
of  the  Name  plants*  livinj'  on  the  snowv  reirio.i*  of  1h<' 
Aijo  or    I'yreiHM"^,  and   in  the  extreme  northern    pa-ts 
of  Kurope  ;   !>ut    it    i^    far    more    lemarkalde,    that    tlie 
plant.-,  on  the   White   Mountani^.  in  the  I  nited  Sta-«« 
of  Aineriea,  are  all   the  «ame  with   tho-e  of  l-ihradir, 
and   nearly  all   the  same,  as   we  hear  from   A^^a  <;ray. 
witii  those  on  the  loftiest  mounbiins  of  Kuroy*-'.      V.y'U 
ae  luiiiT  aiTO  as  1747,  !"i<h   faet.s  led  (ii:ielin  to  rondude 
that  the  Kanie  spe.  les  must   have  heen    in<iej)e!identlv 
created  a'   M«veral   distiiu't  ponits  ,  and  we  miirht  have 
remained    in    this    fvin  e    belief,   had    not    At'^assiz   and 
others    called   vivid    a  tention    to    the    (ilaoial    period, 
which,  as    we  shall   immediatelv   see,  afford-.    \    -impli 
explanation  of  these  facts.      We  have  eviden-  e  f)f  almost 
every    roneeivahle    kind,   ortranic    and    inorjranic,   that 
vrithni  a  very  recent  jfeolotrieal  period,  central  Kurope 
and  .S.irth   Amerioa  suffered   under  an   Arctic  climate. 
I  iie    ruiii'»   ol  a   iioiiSr-   i»uriil    i>y  ure   iio   noi    icw    i;;i":« 
tale  more  plainly,  than  il(»  the  mountains  of  Sc«»tland 
ind  W  ales,  with  iheir  ..coreii   flanks,  poli.^hed  Hurfjcen. 


(JE(X;RAI'HICAL   DISTRIBtmON 


329 


ind  penciled  Injuldprs,  of  the  icy  streams  with  whirh 
rhtir  valleys  were  Utely  tilled.  So  jjreatly  lias  the 
rliniatf  of  Fliimpe  rhaiitod,  that  in  Northern  Italy, 
_M>i;iiitic  moraine*!,  left  by  old  trlaciers,  are  now  rlotlifd 
}>y  the  vino  and  maize.  Throughout  a  larp:e  i«art  ot 
the  liiited  States,  erratic  houlders,  aiul  rocks  score<i 
hy  drifted  iceiier{rs  and  ♦  oa«t-icG,  plainly  reveal  a  former 
cold  jHTiod. 

The  former  influence  of  the  jrlncial  climate  on  the 
iistrihutidn  of  the,  iiihahitanU?  of  Kurojw,  as  explained 
•■v.th   r.-markahle  clearness  by   Kdward    Forties,  is  snl)- 
xTantially  as  follows.      Hut  we  shall  follow  the  changes 
more  re.idilv,  !>y  supposing  a  new  ^'lacial  {>eriod  to  come 
<lowly  on,  and   theji    \t&^<  aw.iy,  a.s  formerly  occurre-l 
As  the  cold  came  on,  an>      i-  each  mi^re  suutiierii  zone 
'.'.anie  fitted  for  arctic  hein:rs  and  ill-titted  for  their 
turn.er  more   temperate   inhahitjints,   the   latter   woul"! 
tie  supplanted  and  arctic  pr<-(i notions  would   take  the  r 
.'aces.      The  inhahitants  of  th.>  more  temperate  refrions 
■ould  at  the  same  time  travel  southward,  utiles.^  tln^y 
••re   stopped   !>y   harriers,   in    which   case  they   wculd 
cri-h.      I  he   mounUiins   would    Jerome   covered    wilh 
nou-   and    ice,   and    t>ieir   former   Alpine    inhahitanN 
^^nuid   ri.'-cend   to  the   plains.      Hy  the  time  that  the 
cuiii    had    reachp<l    it.s    maximum,    we    should    have    a 
uniform   arctic   fauna  and   flora,  covering   the  central 
parts  of  Kurope,  as  far  south  as  the  Ah»  and  I'yreneeji, 
and  even  stretchini;  into  Spain.     'Hie  n<iw  temperate 
rf::ions  of  *he  United  States  would  likewise  be  covereo 
hy  antic  plant-  and  .mimals,  and  these  would  be  nearly 
the  same  with  those  of  Europe  ;  for  the  present  circuir 
pulir  inhabitants,  which  we  suppose  Uj  have  ever\  wiieir 
lra\e;lfd    southward,    are    remarkably    unif<irm    round 
the  wnrld.      \\'e  may  suppose  that  tlie  Glacial  pertod 
>amo  on  a  little  earlier  or  Inter  in  North  America  ihan 
n  l.iirni.e,  m  will  the  southern   mifrration   there  have 
licen  a  little  earlier   or  later;  hut  this  will  make  no 

1  .  .V «     :■■     «1...    ('.Lrtl     raulllt 

';:::•:';":;•.."     :  i  i     •.  r :  "^     ■  ■  :i  t»  t     •  *  ■ — -  .  .  - 

A«i  the   warmth   returned,    the   arctic    forms   would 
ii-tieal  uo'*h«ard.  closely  followfvl  up  in  thoir  retnal 


"m 


L 


a.*^' 


ON   THK   OKMilN    OF    hl'KC  IKS 


I 


>iv  tlif  prorlurtioiiv  (it  the  nutn"  tPm|MTat»'  retrioii»». 
Anil  an  tin?  miiow  nu-ltt'd  from  tlie  bases  <»f  the  tixmii- 
fains,  tlie  .'irrtic  tonus  would  spi/.e  ou  tlie  «Uare<l  aiul 
«h:i'.v»'<l  ::roinid,  always  a'ceiidiiitr  hiirher  and  hi^'lior, 
,v-  the  warmth  iiiiTeased,  whilst  tlieir  lirethren  were 
l»'ir'-m"a;  their  northern  jotirtiev.  Hence,  wlien  the 
v^ann  h  had  tiilly  returneil,  the  >^ime  aretic  speeies. 
.vlii.ti  had  hitely  lived  in  a  l.ody  tot;»'tlier  on  the 
lowl.uids  of  the  Old  aii<i  New  Worlds,  would  !>e  let\ 
isolait  d  on  distant  mouiitain-«iimmits  ihaviiiir  been  ex- 
rernmiated  on  all  lesser  heiirhts)  and  in  the  aretic 
e^ions  of  hotli  heiiiisphere>. 

liiiis  we  can  understand  the  idenfit\  ot  many  plants 
,«t  poiiius  -o  ittmiensely  reniote  as  on  tiie  riuiuntains  ot 
tlie  I  iiit«*d  States  ami  of  Kiirope.  ^^  e  can  thus  also 
iindersUnd  the  fact  that  the  Alpine  plants  of  each 
ii.ouiitain-ranirt'  are  more  .'-jtecially  related  to  the 
arctic  forma  livinir  due  north  or  nearly  due  north  o! 
them:  for  the  miuTation  as  the  cold  came  on,  and  the 
re-iniLTation  on  the  returnintr  warmth,  will  ^reiierally 
have  heeti  due  smith  and  nortli.  'Hie  Alpine  plants, 
lor  example,  of  Scotland,  rh  remarked  l)y  Mr.  H.  (.  . 
\\  atsan,  and  those  of  the  I'yreneea,  as  remarked  by 
Ix.iiiH.ud,  are  more  especially  allied  to  the  p!ant«  of 
northern  Scandinavia;  those  of  the  Lniicd  >tates  to 
l^ahrador  ;  tho>;o  of  the  mountains  of  Siberia  to  the 
arct"-  regions  of  that  country.  ITieso  views,  grounded 
as  thev  are  on  the  perfectly  well-ascert;iined  (.ccurrence 
of  a  former  (facial  period,  »;eem  to  me  to  evplain  in 
-I.  satisfactory  a  manner  the  present  distril)Ution  of  the 
Alpiiie  and  Arctic  productions  of  Kunine  and  America, 
that  Hhen  in  other  regions  we  fnid  tne  same  -pecie- 
.»•!  di-lant  m«»untaiii-summits,  »»>  may  almost  conclude 
.vittiout  other  evidence,  that  a  colder  climate  permitte<! 
'heir  former  micratioM  across  the  low  intervening  tracts, 
riii«.o  bcc«ime  too  warm  for  their  exi>-tence. 

If  the  climate,  since  the  Cllacial  period,  has  ever 
rccn  in  aiiv  urrrvrc  wafTnrr  than  at  pre^nt  '■a-  <^r,^^ 
•jeol<.;rist«  m  the  I'nited  States  believe  to  have  l>een 
'liH   case,    chietlv    from    the    dist riluitioti    of   the    fossil 


<iKO<;RAPHI(  AL   DISTKimrioN 


3.'n 


(Mifitlifxlon),  tlien  the  ar<-tu-  and  tmipenue  prodiictiorw 
.vill  at  a  very  Lite  jK-riod  have  marohed  a  littlo  further 
lorth,  and  siih<p»iiipiitlv  have  retrf-ated  to  tlieir  present 
homes  ;  hut  F  have  min  with  no  satisfactory  evidence 
Aith  re««pect  to  this  intercalatr.l  .-litir>«tly  warmer  peri«).l. 
-UM-e  the  (flacial  period. 

The  arctic  forms,  durinir  tlieir  lontr  southfrti  inie-r.i- 
tiou  and  re-mi<rration   northward,   \m!1   have  U"U  (><- 
oo-ed  to  nearly  tlie  !«»mo  climate,  and,  as  i«»  especially 
to  \*e  noticed,  they  will  have  kept  in  a  ho<ly  totrether  ; 
.  (.nseqiiently  their  mutual  relations  will  not  have  Wcm 
much  distur'hed,  and,  in  accordance  with  the  principles 
Kculcated    in   this   volume,  they   will   not   have    heen 
iahle  to  much  moditicAtion.      But  with  our  Ali-me  prrv 
hictiuiis,  lef\  isolated  from  the  moment  of  the  returiv- 
titf  warmth,   first  •«.t  the  bases  and   ultimately  on   the 
-ummits  of  the   mountains,    the   ca-e   will    have    heen 
■^onu'^hat   different :   for  it  is   not  likely  that   all  the 
-ime  arctic  species  will  have  heen  left  on  mountain- 
ran-'cs  distant  from  each  other,  and  have  survived  there 
over  since:  thev  will,  also,  in  all  prohahility  ha\e  in- 
come mintrled  w'ith  ancient  Alpine  species,  which  must 
ti.ive  existed  on  the  mountains  before  the  commence- 
II  .-lit  of  the  (llacial  epoch,  and  which  during  its  coldest 
'„ri(Ml  will  have  been  temporarily  driven  down  to  the 
1  Inns  ;  they  will,  also,  have  been  expoHed  to  som»«wlial 
.different  climatal  influences.      'ITieir  mutual   relations 
will  thus  have  been  in  some  decree  disturbed  ;  cons*©- 
.' lently   thev  will   have  been    liable  to   modification  . 
■md  this  we  find  has  been  the  case  ;  for  if  we  compan' 
the  present  Alpine  planta  and  animals  of  the  -everal 
i'r(>at  KuropeAn  mountain-ranees,  though   very  munv 
nf   the  -pecies  are  identically  the  same,  some  present 
varieties,  some  are  ranked  as  doubtful  forms,  and  some 
t.'*   are  distinct    yet   closely    allied    or   representativ 

species.  , 

In  illtistratintr  what,  as  1  l)elieve,  nctiially  took  place 

i  ,    ii:;r    the   Viiatiai    prfiSJU,   l   aar---!-;  —  ;      r.-.v    ^ -_ 

nu-nocmeiit    the  arctic    productions  were   a«    uniform 
-ound  the  polar  regions  a«  they  are  at  the  present  day 


.'i,32 


ON   THK    ORKilN    OK   S1'E(  lES 


I 


I    t 


i 


Hut  tlirt  forH^oiii;;  remarks  on  di-trihiitioii  applv  ijn? 
only  to  strictly  .irctir  toriii'*,  Imf  ajno  to  rn.iuy  siil>- 
«r<tii-  .iiMJ  to  Home  trw  iiortluTii  tonipprato  forms,  for 
POTTie  (it  th»'«p  are  tlu'  Banif*  on  tlu'  l<>wor  ninuiitain.a 
and  (in  the  pl.iins  of  North  Anicricj*  and  Kiir(i|«»'  ;  and 
it  itiav  lie  rc.i-diialdy  a.'^ked  ho'v  I  arcouiit  for  tin- 
iiwcss;irv  li'-LTcc  o(  uniformity  of  the  Hul>-.'ir<'t;(:  and 
nf»rllieru  tt'inpcratp  forms  round  tho  world,  at  th( 
romnicnr»»Tni»nt  of  tiic  (ilarial  fM»ri<'d.  At  tlic  |>r»'sent 
dny,  tli<»  sub-arctic  and  rthprn  ti'inperalc  |ir(Mjijc- 
ttoiiK  ot"  tlie  Old  and  New  i\'orlds  are  scparal^'d  from 
each  oi'hur  by  the  Atlantic  ( )cean  and  by  t'no  rxtrcmc 
northern  part  of  the  f'acific.  I>urimjr  the  (jlacial 
'•••nod,  I* hen  the  inhabit. mtw  of  the  < 'Id  and  Ne^* 
\\  -i-lii,  lived  further  southward^  than  at  pri»scnt.  thev 
!i)u»'  iiave  been  still  more  <'imjilet«'lv  -e[iarat<'d  by 
•vider  >^;>'ue><  of  ocean  I  l>elie\c  the  alio\e  dit?i<uhv 
may  be  -urmount4»d  liy  lookintr  to  still  earlier  diatiircH 
of  clim  lie  of  ati  o|i|Hisite  nature.  ^V^•  have  trood  reaMin 
'o  believe  tlat  duriiij;  the  ne'ver  i'iiocene  period,  he 
fore  'lie  <ilacial  p|»och,  and  »'iil»t  tlie  niaiontv  oi  the 
Tib  kbitan!.><  of  th(>  world  -"ere  s|iecificallv  the  ^*ame 
1,-1  no-.v.  the  climate  was  warmer  tlian  at  tlie  present 
day.  Hence  we  may  "-iippose  that  tlie  ortraniem-;  now 
livintr  under  the  (limate  of  latitude  t50\  durintr  the 
I'iiocene  period  lived  further  north  under  the  Polar 
t  irdo,  in  latitude  *]i\"-iu'  '.  and  that  the  strictly  arctic 
productions  then  lived  on  the  broken  land  ntill  i:earer 
*o  the  pole.  N^^v  if  we  look  it  a  (flobe,  we  shall  see 
that  undiM  the  i'olar  '  irde  there  is  almost  continuou.s 
i.md  fr(mi  western  Kurope,  throuirh  >i!ieria,  to  ea.-- tern 
Allien.. I.  .And  to  this  continuity  of  the  circumpolar 
land,  and  to  the  ronse(|uent  freedom  for  intermitra 
tioii  under  a  more  favourable  cliinnte,  I  attribute  the 
neco-^iry  amount  of  uniformity  in  the  sul>-arctic  and 
northern  teiiiperato  [(nxiijetions  of  the  < 'Id  and  New 
\\ drills,  at  a  period  anterior  to  the  (ilacial  epoch. 

fieiievinff.  from  rivLsous  betore  aiJudeti  to.  thai  our 
continents  have  lonj;  remained  in  nearly  tlie  s;ime 
relative  i>osition,  thoui:h  subjected  to  larjfe.  but  partial 


I     I 


tj^^^aim^i^:.^^'^ 


(;ech;kai'HICAL  DisnuBrTioN 


.iiVl 


oiMill.itioiiB  (it  level.  I  am  -<troiiirly  iiu-line«l  to  extemi 

th«>  above  vi«'vr,  and  to  infer  that  (luriiitr  •miii**  earlier 
iiiil    'till   wiirmer   jieri<Mi,   xiuh   an   tlie  «tl<U-r    I'lioioiie 

i)«Tn)<l,  H  Iar;re  nutiil>er  of  the  Kaine  plaiiU  and  aniiual-! 
iihaliited  the  almtist  contiimoUH  tirrutn polar  land  : 
mil  that  t)it-e  plants  and  animaN,  i.oth  in  the  ( 'Ui 
uid  New  W  orhls,  Wtrari  -lowly  to  nufrate  -oiilhwari" 

ii-t  the  (lunate  herame  less  warm,  lontr  IxMore 


the 


.•ncenient  of  the  iJlatial   period.      We  now  see 
'lieve.  their  desiemianls,  tno 


as   I 
^tlv  in  a   iiui<liii.(l  con 


litiori. 
'tate*. 


Ml  the  eeiitral  parts  of  Kurope  and  the  I  niteil 
(In  this  view  we  can  under-<tand  the  relation- 
lip,  v*ilii  very  little  identitv,  between  the  ](ro<lii.tions 
i<(  North  Anieric;i  and  Kurope,  a  relationship  v^nich 
1-  nio-t  rernarkahle.  consideriinr  tlo*  distance  of  the  two 
iiie.i.-'.  and  their  separation  hy  the  Atlantic  ( >ie.an.  Wf 
,  ,in  fnrther  iiiuler-iand  the  -insular  fac-t  remarked  oi^ 
,\  several  oh-»'rvers,  that  the  production-  of  Ijirope 
lid  America  durinjr  the  later  tertiary  stages  were  more 
.  luseiy  related  to  eacli  other  than  they  are  at  the  proent 
time  ;  for  durinir  these  warmer  periods  the  northern 
[.•i'-»<  of  the  (Md  ami  New  Worlds  will  have  heen  aimo.-t 
r>i!itinii..u>lv  united  hy  land,  >er\  in-r  a-  a  hridt--*'.  -in<-e 
renilere<l  impassable  by  cohl,  for  the  intcrmi;:ration  of 
rht'ir  iiiliabit.'iTit>. 

I  >iir:u;r  the  slowly  decreasiiijr  warmth  of  the  I'lioceiie 
[lenod,  a-s  soon  as  the  spe<ies  in  comn.on,  u  liirh  in- 
!ial.ite<l  tlie  New  and  Old  Worlds,  mijrrated  -outh  of 
•li"  Tolar  Circle,  they  must  have  been  completely  cut 
i(f  from  each  other.  This  reparation,  ;us  far  a>  lio- 
•iiore  temjx'rate  production-  are  concerned,  took  place 
ionj  aire-  ajro.  And  as  the  plant-  and  animals  mi^rraU-d 
-MMthward,  thev  will  have  become  miii-led  in  the  one 
jTcat  re:rion  with  the  native  American  productions, 
iiui  ha\e  iiad  to  compete  with  tlieni  ;  and  in  the  other 
-rt'il  rt'iiion.  with  th«)-e  of  the  Old  World.  C  onse- 
.liiciiMy  we  have  here  everythiiiir  favourable  for  much 
->, .  .  _V^*:.._.  f,,-  r.,..  vY^,.\^4k  rY'^fifHhi'.it ion  than  witli  the 

.\l!)iie  productions,  left  i.-<datwl.  within  a  much  more 
re.  ent  {Hiriod,  on  the  several  mountain-rmnf^e*  and  on 


-  i 
i 


I 


;«w 


ON    INK   OKKJIN    OK   hl'K(  IKS 


the  ciPlic  laiidH  ot  tl.o  two  MurldH.  lleiue  it  has 
com.',  that  when  we  rompure  llu'  now  liviiitf  prctdu. - 
ti(.M<  of  Uu'  Hrm|.t.T..lr  r.tfions  --t  tlie  NVw  \n>\  Old 
W  orlil<,  we  IiikI  m'iv  If"  idt'nlical  -i.rcMW  (thoii-li  .\s;» 
(.rav  Jias  hit.lv  i"!!..'"!!  that  nK.n-  j.lanb*  :iro  id.-iitiral 
than  wa,  forim-rlv  ^tl|.po^pd),  Lut  w<^  tiiid  iii  every 
Tt-at  cla^K  many  form^,  win.  li  some  natunilislH  rank 
as  iriM)LMaphi.al  race-,  and  others  as  distinct  sjx'Cie.s  . 
:.n,i    a    host   of  .los.-K    ..IIkmI    or    rei-resoutative    forms 


hich    are    ranked    hy    all    naturali-'- 


w  hii 


as    spoi'itiiMii V 

As  on   the  land.  >..  in   the  uater^      i   the  wa,  a  slow 
southern    iinjrration  of  ft  marine  iain.a.   whu-h  dunni; 
the   I'lio.eue  or  ev.'ii  a  somewhat   ••  irlier   period,    was 
nearly    unitorm    alonK    tlie    c«»ntinuous    ^hores   ol    the 
Polar  <  ir.le,  will   ar«()iint,  on   tlie   theory  of  modihca- 
tion,  lor  many  clos,!v  allied  f..rms  now  livinjf  in  are;i> 
,„,Mpletely  sundered.      Ihus,   1   tl.ink.  we  can   under- 
sUnd  the  presence  of  n.anv  existintr  and  tertiary  repre- 
sentative forms  on  the  eastern  and   western  siiores  oi 
te-nperate  North  America  ;  and  the  still  more  ^tnkin- 
caso  of  many  closeiv  allied  crustaceans  (as  described  in 
Dana's  admirable  work),  of  some  lish  and  other  marine 
animals,  in  the  Mediterranean  and  in  the  seas  ot  Japan, 
-  areas  now  separated  hy  a  continent  and  hy  neniy  a 
hemisphere  of  ecj'.iatorial  ocean. 

Ihfse  cases  ot  relationship,  without  identity  ,  ol  the 
,;, habitants  of  sesis  now  di>ioined,  and  likew-e  of  the 
oast  and  present  inhabitants  of  the  tomoer.ite  laiids  ot 
North  Aiiien.a  and  Kun.p'.',  are  inexplicable  on  the 
ll.eorv  of  creation.  \\e  cannot  sa>  that  they  ha\  e 
t,een 'created  alike,  in  correspondence  w  ith  the  ueany 
similar  plivsical  conditions  ..f  the  areas  ;  tor  it  we  com- 
..are,  for  instance,  certain  i>arts  of  South  Aincnca  with 
liu-  M.utherii  coniiiicnts  of  the  Old  U  ..rl.l,  we  see 
<ountri.-s  closeiv  corresponding  in  all  their  physical 
,  ondilions,  but  with  their  inhabiunts  utterly  dissimilar, 
lint  wf  must  reluiii  to  our  uiorc  imiiirtiiate  su-ViO^'t, 
the  t.lacial  i)erio.l.  1  am  convinced  that  Forbes's  view 
nun    l-e   larirelv  extended.        in    Kun.pe    we  have  the 


.irf-.»43y^^- 


GECHiRAr.'iCAL    1)IST111BI"''I()N  ALI 

pUuit'St  evid»Mi<»' «it  tln>  cold  |»«'rio<l,  troin  the  wi'slerii 
hhoro-  of  llrilaia  to  tlio  (Jural  nmtre,  .iiul  M)utliwanl  to 
the  rvriMuu's.  We  in.iy  infer  troin  the  frozen  niainrnal- 
,iiid  ii'i'ur*'  of  lh»' ino  iiitiiii  ve^.'-ftatiuii,  liat  SilxTia  wan 
siinil.iily  atlfited.  Aloi;,'  fhr  Himalaya,  at  iMiiiits  Shki 
mileh  apart,  »rlat  ifr-;  havi'  liMt  thf  iii.irksof  tht'ir  fornuT 
low  (l««>.{M»t  ;  ami  in  Sikkini,  l>r  Hooker  saw  mai/.e 
trrowiiij.' oti  ciirritilii- aiicifMil  in<)rain»>s.  ^outl;  of  tliH 
♦•(jiiator,  \*t«  h.i\»'  •.•line  ill  roct  evidftire  of  former  trla<  ;al 
!u.tion  in  New  /.ealaml  ;  and  the  xame  plant*",  fonntl  on 
wi.ii'ly  separated  mountains  iutliat  i-laiid,  tell  tin  s;iiii«' 
>torv.  If  <»!!»>  iccMijiit  wtiH-h  lia>  Iwen  pultlishrd  can  It- 
trus'U'd,  v»e  iiav<'  direct  e\iilen«e  of trhwial  action  in  the 
-()Uih-i-;i»t«'rn  rnriicr  of  A;i«'r:ilia. 

l/ookiiitf  to  America  ;  in  Wir  northern  half,  ice-tmnic 
•  ,„'t)i»'iits  of  ro«k  have  Iwen  ohserved  on  the  ea^lern 
-,dc  a--  i.ir  houth  a>  hit.  ;i<". -.'57',  and  on  the  shores  nt 
in-  I'acitic,  where  the  climate  is  now  so  differeiK,  a> 
t.ir  south  as  hit.  4<'  ;  erratic  boulder-  hav»',  al-o,  U«en 
•M.'iced  on  the  Kooky  .Mountains.  In  the  (  ordillen  of 
i;.|ualurial  South  .\riHTi<a,  jrlacitTs  mice  eMeniled  tar 
h.low  their  present  level.  In  central  (  hi!i  I  <a- 
l.-'llni^lltHl  at  trie  structure  of  a  v.ist  nmund  of  detri;ii-. 
aixiul  Wx>  fee;  in  hei^-'lit,  crossiii;:  a  valley  t  f  the  .\ndc-. 
md  this  I  now  feel  convinced  was  a  tMiran'ie  morain--, 
lift  far  lielow  any  e.xistinir  glacier.  Further  s«iuii> 
■  n  l>oth  ^idc-  of  the  continent,  from  lat.  -41  to  tic 
-outliernmost  extremity,  we  have  the  dearest  evide:i.>> 
.tf  former  jflacial  action,  in  hujre  houlders  transported 
:  u-  from  tlieir  parent  source. 

We  do  not  kiio.s  (hat  the  (ilacial  ejMwh  w:is  strict!) 
-imultaneous  at  the-e  several  far  distant  points  on  o]" 
pos;  ,.  sides  of  the  world.  Hut  we  liave  tro«Ml  e'.idencf 
in  almo>l  every  case,  thai  the  epoch  ah-  indudcl  wi»hin 
•he  latest  ^Tolojrical  peiioii.  W  e  have,  also,  excelleiii 
evidence,  that  it  endured  for  an  enormous  time,  a- 
ineasured  by  years,  at  e  loh   point.     The  cold  m.iy  have 

» 1.^..r>    <<.>'i>.<.1       p-irliiir     at      olio    luiillt      (it      *  }u' 

•  tr:::T-    tril,    •■ft      iid  -  ^--    ^  *.  •»  ■•  ••  j     ' —-      ; -      

:rlot»e  than  at  another,  but  seeing  that   it  endured    tor 
lo/ii:  at   each,  and   that   it   was  contemooraneous   in   ^ 


-^AA*ui^lt^^^i^ar.lSM 


n:n\ 


ON   TIIK    OHKilN    <»K   SPKC  Ih> 


■>' 


I 


(jt'olrii.'-ic.il  »i'iim«.  if  -^-fnis  ti>  me  pr<il».itilf  'liat  it  w.i.-.,<liir 
iiiC  :i  I  :irt  al  If  Lit  of  tlit>  piTiod,  .ittit'ilh  •«imiilfniii>im> 
■  lirmii^liniit  iIm'  Murl'l.  \\  itlnHit  Minu'  <Ii*tiint  t»\  it|«>tM«' 
to  till'  fdntrary,  vv««  may  at  len^t  admit  ax  prnlialdp 
that  till"  irlanal  at-titiii  wm*  Himnltaiicoii"*  on  Mm-  »T»itfrti 
a'lil  wottTii  hidtw  of  North  Aiiutkm,  in  th<'(  nnl.liiTa 
iiiiiliT  the  »'i|iiat«fr  and  iiiidtT  the  wariinT  t.-m[»»'rat<' 
/"III-,,  atid  on  hoth  "iidi's  of  the  >4oiitherii  ••\»r'imty 
ot  the  roiitiiiftit.  If  this  he  admitN-d,  it  i>  dilh(  iilt 
to  avoid  helifsi'itj  that  th»»  ti-mp.-rat iir»'  of  tlo-  w[iid«- 
v*orlii  WOH  at  this  |H'rio<i  'iiiiiilt.iii«*<Mi-lv  cooler.  lint 
It  would  >4nffi(t«  tor  mv  iMiipoue,  if  t)i-  trrnpcrature 
v«a-*  ;i'  th<'  same  titn^  h)W»'r  ahmi^  rerfam  hro.id  h«dtn 
of  hdiiritiide. 

« 'n  thi-<  view  of  the  whole  world,  or  at  U'.i»t  of  hro  id 
loii^ritudinal  lultM,  haviiijr  heeii  vimnlLifit misly  .-older 
tmiii  [ifdf  to  pole,  iniicii  lush'  « .m  hi-  thiown  on  th<' 
I'l'M'tit  ili-'trihiitiuii  of  iiU'iitical  and  allied  '[lecies. 
ill  Aineric.i,  Dr.  Hooker  has  ^hown  that  het^i-i-n  htrty 
Old  titty  of  the  floweriinr  plant.s  of  lierra  d»'i  Kiieiro, 
t'>rmin^  no  inconsideralile  part  of  it.s -tant)  fln'-.k,  are 
eonimon  to  Kurone,  eiiorinou>'ly  remote  a-*  tlif-f  two 
p":nt.sare;  and  tliere  are  in.iny  rlosfly  allied  >pe(ieH. 
'  'I  the  lofty  mountani^  of  e(jii.itorial  America  a  ho^'l  of 
p<  (  uliar  -pccies  l>eh>njriri:r  to  KurujKvm  irenera  occur. 
<  Ml  til.-  hiirlu'st  mountains  of  Brazil,  some  tVw  Kuropeaii 
t'>  iiera  v\(re  lounil  l»y  (iarihier,  wiiieh  do  nut  exist  in 
liic  Wide  interveiiintr  hot  countries.  S(»  on  the  Sill.j  o*' 
I  aracca<  the  illustrious  llumholdt  htiij-  atfo  ton.  d 
tijtecii'^  t.«'l.in;fin;,'  to  t'cnera  characteristic  of  the  '  o.-dil- 
Icra  ( 'n  the  mount;iins  of  Ahyssinia,  M*\«'ral  Kumpca'i 
lui  iii>.  atiii  s(mie  few  reprt'scntatives  of  the  peculiar  tlor  i 
ot  thi' (  ape  of  (ioi  '  Hope  o<'cur.  At  the  (  apt' of  <  iood 
ill'].,'  a  \cry  tew  K  i.ipeati  speoie.><,  helioved  not  t<»  liave 
•ti-u  iiitidduced  hv  man,  .unl  on  the  mountain-.,  ^ome 
few  repir~i>ntati\  e  Muidpi-an  torm>  are  found,  wliii  h 
h.i\e  nt»t  tieen  discovered  in  the  intertropical  parLs 
o;  .iiP. »*."».  \  fii  me  i  1 1  iiiaia^'a,  aiiii  <>ri  ifit}  i.-^.'i.'i'c*! 
mountain -rini^^es  of  the  peninsula  of  India,  on  the 
iicii:ht.«  of  (  e\i«>n,  anti  on  the  volcanic  conci*  ,<>  .fava 


m"^-^-' 


<;K<H;RAI'm(  AL    niSTRIBlTION 


.•1.17 


maiiv   plantH  orcur.  «'ith»'r  identically  tho  wun«  (»f  r»»- 

[  -<'s«'iititi|f  viuh  other,  and  at  tlw  sanu*  timo  r«'pr»n'nt.iii(f 

l.itit-H  of  KiirnjM',  not  found  in  the  intervpnintr  h<»t  in*- 

irids.      A    li»f    <)f  th»»   tfpn««ra  colliTtrd    on   tln»    loftier 


iks  of  Java  rainps  .i  nirtiire  of  a  mlU'rfion  tnad«  on  a 

II  in  KurojM'  '  Still  rnor*-  -trikitiK  ">  ''"»*  ''ft  ''«at 
-.iuth«'rn  Australian  fornis  are  I'Uviriy  rrpn"^pnt»Mj  by 
;.i  iitH  crowirij''  on  the  nummiLs  of  tho  niountaini*  of 
l;.iriieo  Some  of  thi«j»«  Austriliin  fonnt.  an  I  hear 
rriitn  1  >r.  Hookrr,  extend  alona:  the  hfiirlif^  of  tht- 
p»'nin«iiia  of  Malaira,  and  ar»*  thinly  sratt«Tt'd,  on  the 
(•!H'  hand  ov»'r  India  ainl  on  tho  other  a.«*  far  north  .'w 
J  t[>;»ii. 

I'll  the  Houthern  rnountain-;  of  Australia,  Dr.  I. 
\I  )ll<'r  has  dinooverpd  several  Kurr)j>»'aii  >iperies  ;  other 
«p.i  le*;.  not  intro<luced  by  man,  mTur  on  the  lowLindH ; 
and  ;i  lonsr  li'-'t  can  In.'  jjiven,  an  I  am  informed  liy  Dr. 
lioukiT,  of  K'jro{H>an  jfeuera,  found  in  Australia,  hut 
tiot  in  llie  intermediate  torrid  refno'is-  In  <'•«*  ailruir- 
:Uile  Introductuin  to  tti^  hlom  of  .\'nr  Ztainnd,  by 
Dr.  5lo(»ker,  analojrou«*  and  s-trikin^j  fact**  are  {riven  in 
re::  ird  to  the  plants  of  that  lartre  island.  Hence  we  M'e 
tli.it  thnnitrhout  the  world,  the  plant**  jrrowinc  on  the 
fimre  lotty  mountains,  and  on  the  temperate  lowlands 
of  the  northern  and  southern  hemiMpberen,  are  some- 
times identically  the  same  ;  but  they  are  much  oftener 
»[«e(iti.ally  difitinct,  thoutfh  relate«l  to  each  other  iu  a 
most  remarkable  manner. 

Hiis  iirief  abtrtract  applies  to  plants  alone  :  some 
stricil)  aiKiloirous  fartM  could  U-  jfiven  »)n  the  distribu- 
tion of  terrestrial  animals.  In  marine  productiona, 
piniilar  cii^es  occur  ;  as  an  example,  I  may  quote  a 
.'em.irk  l.v  the  hitrhest  authority,  Prof.  Dana,  tliat  *  it 
is  certain !v  a  wonderful  fact  that  New  /eaia;id  should 
liiive  a  (fo-ier  resemblance  in  it.s  Crustacea  to  <ireat 
U.-ifain,  its  antifiode,  than  to  any  other  |Kirt  of  the 
vorld."  Sir  J.  Iliehardson,  also,  speaks  of  the  roappear- 
<iine  on  the  siiiirea  oi  New  /.eiiiaud  i  ii.>>tii.iiii.'»,  etc., 
mI  riorfliern  forms  of  fmh.  Ur.  Hooker  informs  me 
tiiat  twenty-tive  species  of  .Altr<e  are  oommou  to  New 


^^^M.: 


3.'J8 


UN   THE   ORIGIN   OF   SPECIKS 


n 


\i'-  i 


I 


tiff 


'!| 


!   I 


Z»r.ilanfl  and  t(»  Kuropo,  but  hav.-  not  been  found  in  tiif 
inicrmediate  tropifuf  seas. 

It  should  be  olwerved  that,  tho  northern  sp.Tuw  and 
forms  found  in  the  poutliern  j)arti5  of  the  southern  hemi- 
-phore,  and  on  tho  niountain-raiiire«  of  the  int»'rtro]>iial 
r.'jrions,  are  not  arclir,,  hut  hehjn^'  to  the  northern  tem- 
perate zones.  As  Mr.  H.  C.  W  alson  lias  recently  re- 
inarkefi.  '  In  reredinjf  from  polar  towards  equatorial 
latitud.s,  the  Alpine  or  mountain  floras  really  liecon.e 
les-  and  less  antir."  Many  of  the  forms  livinjf  <»n  the 
mounUins  of  the  warmer  reerioTis  of  the  earth  and  in 
thf  NouUiern  lioinisphere  are  of  doubtful  vaiu.-,  l»»'inif 
r.iiik.'d  liy  soin.-  naturalists  as  speeirtcally  distinet,  bj 
others  as  varieties  ;  but  some  are  certainly  identical, 
iind  many,  thou^rh  i-losely  related  to  northern  forms, 
must  1k>  ranked  iis  distinct  species. 

Now  let  us  see  wli.it  lijrht  can  be  thrown  on  tlie  iore- 
iroiii;;  fact^,  on  the  I>elief,  supported  as  it  is  by  a  larjrc 
lK)dy  of  jreolojrical  evidence,  that  the  whole  world,  or 
a  la'rire  part  of  it,  was  during  the  tilacial  period  simul- 
taiK  uiijy  much  colder  than  at  present.     The  (ilacial 
period,  as    measured  by   years,   must    have    lieen  very 
lonp  ;  and  when  we  remember  over  wliat  vast   spaces 
M.iiic  naturalised  plants  and  animals  have  eprea<l  *ithin 
a  few  centuries,  this  period  will  have  been  ample  for 
.iiiv  amount  of  migration.     As  the  cold  came  slowly  on, 
all  the  tropical  plants  and  other  productions  will  have- 
n  treated  from  both  sides  towards  the  equator,  followed 
ill  tlic  nar  by  the  temperate  productions,  and  these  by 
the  arctic  ;  but  with  the  latter  we  are  not  now  concern»'d. 
I'he  tropical  plants  probably  suffered  much  extinction  ; 
how    much    no    one   can    say  ;    perhaps    formerly    the 
tropics  supported  as  many  species  as  we  see  at  the  pre- 
sent day  crowded  together  at  the  (ape  of  <iood  Hone, 
and  in  i»arts  of  temperate  Australia.      As  we  know  that 
many  tropical  plants  and  animals  can  withstand  a  con- 
siderable amount  of  cold,  many  mig.it  have  escaped  ex- 
termination durintr  a  moderate    fall    of  lemperauire. 
more  et«pccially  by  escaping  into  the  lowest,  most  pro- 
tectee!.  and   warmest  district*.      But  the  -^reat  fact  to 


GErKiRAPFIK  AL    OISTIIIBITK  )N 


avj 


bear  in  mind  is,  that  all  tropical  productions  will  have 
suffered  to  a  certain  extent  On  the  other  hand,  tiu- 
temporate  productions,  after  niijrrating'  nearer  to  the 
p<)uat«)r,  tlioutrli  Iht'v  will  liave  l>eer»  placed  under  nomo 
■*hat  new  conditions,  will  have  suffered  less.  And  it  l^ 
r««rtain  that  many  t<*mperate  planus,  if  prot»»rted  from 
tho  inroads  of  competitors,  can  withstand  a  much 
warmer  climate  than  their  own.  Hence,  it  seems  to  mo 
[)ossihle,  bearing  in  mind  that  tl'*'  tropical  production> 
were  in  a  sufferintj  state  and  could  not  have  presented 
I  firm  front  a^inst  intruders,  that  a  certain   number 

>f  the  more  vigorous  and  dominant  temperate  forms 
nii^lit  have    penetrat«d    the    native    ranks    and    have 

t-arhed  or  even  crossed  the  equator.  ITie  invasion 
would,  of  course,  have  i>een  j^reatly  favoure<l  by  lii;r}i 
■and,  and  perhaps  by  a  dry  climate  ;  for  I^r.  Falconer 
informs  me  thKt  it  is  the  damp  with  the  heat  c»f  th»' 
troj)ics  which  is  go  destructive  to  pe.  .;ial  plants  from 
n  teiii|)erato  climate.  On  the  otliei  nand,  the  most 
liiiinid  and  hottest  districts  will  have  afforded  an  vlum 
to  the  tropical  natives.  The  mountain -ran^res  north- 
west of  the  Himalaya,  and  the  lonjf  line  of  the  CordiU 
iera.  seem  to  have  aiTorded  two  jrreat  lines  of  invasion  : 
and  it  IS  a  striking  fact,  lately  communicated  to  me  by 
Dr.  Hooker,  that  all  the  floweriiiK^  plants,  alxuit  fort\ - 
six  ui  number,  common  to  Tierra  del  P'ue^fo  and  to 
Kur'ij>e  still  exist  in  North  America,  which  must  have 
lain  on  the  line  of  march.  But  1  do  n«>t  doubt  that 
some  temperate  productions  entered  and  crossed  even 
tlie  .iiu/iind-g  of  the  tropics  at  the  period  whei.  tiie  cold 
was  most  intense,— when  arctic  forms  had  mierated 
some  twenty-five  decrees  of  latitude  from  their  native 
lountry  and  covered  the  land  at  the  foot  of  the 
!*yrf'nees.  At  this  period  of  extreme  cold,  I  believ*' 
that  the  climate  under  the  equator  at  the  level  of  tiie 
sea  was  about  the  same  with  that  now  felt  there  at 
the  iieiifht  of  six  or  seven  thousand  feet.       During  thi.s 


>L!^^*    ,^ 


^nJi'ert 


Upp;!=ii    tii 


uir;;r  r.,;a!  rD    uj 


tropical  lowlands  were  clothed   with  a   minjflod   tropi 
''al    .!id  temperate  ve^jet-ation,   like  that  now  jfrowinjf 


'  TK.nBim:- 


".^svsfmnr: 


aw» 


ON   THK   OKKilN    OF   SPEXIES 


i 


I 


"t 


*li 


with  stmiitre  luxuriance  at  the  ba.se  of  the  Himalaya,  a»* 
trrrjphi.'ally  <let«TihtMl  liy  Hooker. 

Ilnis,  a8  i  iK'licve,  a  considerable  uumh»'r  of  plant.-,  a 
few  tt-rrcHtrial  aiiimalM,  and  Home  marine  productions, 
miirrated  diirine  the  (ilacial  pericxl  from  the  northern 
iM'i  Honthern  temperate  /ones  into  the  iiitertrdpical 
r»'<rioii<,  and  some  ev.-n  (;ro«j«sl  the  equator.  .\s 
the  warmth  returned,  these  teinixTate  forms  w.mld 
natiiniliy  a.M-end  tlie  hiifher  mountains,  beintr  exter 
riiinat(Ml'on  the  lowland.s  ;  those  which  ha<l  not  reached 
the  e»|ii.itor  would  re-mij^rate  northward  or  souttiward 
Uiw.irds  their  former  homes  ;  but  the  form.><,  .  liietly 
northern,  which  had  crossed  the  eijuator,  would  travel 
-till  further  fr<»m  their  homes  into  the  more  temperate 
latitudes  of  the  or.|M)site  hemisphere.  AlthM\i:rh  we 
ha\c  reason  to  Indieve  from  ^eolotfica!  evidence  that 
ihe  wiiole  body  of  antic  shells  underwent  scarcely  any 
moditication  durintr  their  lonff  southern  mitrratioti  and 
r»'-miirrati(ui  northward,  the  case  may  have  iM^en  wholly 
dilfereiit  with  those  intruding:  forms  which  settled  them- 
<ehes  on  the  intertropical  mountains,  and  in  the 
southern  Iiemi<piiere.  Ihese  bein^  surround»Ml  bv 
stranger-  will  h.ut!  had  to  compete  with  .iiany  new 
forms  of  life  ;  and  it  is  probable  that  sele«-ted  moditica- 
t,.iiis  in  their  .structure,  habits,  and  constitution-  will 
b.ixe  protitcd  tliem.  'Hius  many  of  these  wanderers, 
Ihouiih  still  plainly  related  by  inheritance  to  their 
hrethren  of  the  northern  or  southern  hemispheres,  now 
.xi-t  in  their  new  homes  as  well-marked  varieties  or  ivs 
di-tinct  species. 

It  is  a  remarkable  fact,  strona:ly  insisted  on  by 
Hooker  in  resrard  to  .America,  and  by  .Mph.de  t  aiidoUo 
in  reL':ird  to  .Australia,  that  many  more  identical  plants 
:iiid  lUied  ♦orms  have  ap{»arently  mierated  from  the 
-lorth  to  the  south,  than  in  a  reversed  direction.  \V'e 
see,  however,  a  few  southern  vegetable  lorms  on  the 
mountains  of  Borneo  and  .\byssinia.  I  suspect  that 
thi-  preponderant  m.^ralion  rn>m  norlii  to  suulli  ».- 
due  to  tlie  trreater  extent  of  land  in  the  north,  and  to 
the  northern  forms  having  e^i^ed   in   their  own  home* 


CiKCKJKAPHICAL  DISTRIBITION 


341 


ill  ifreaUT  uumhers,  and  having  consequently  Ikm-u 
adv:iiif»'(l  throu^'h  natural  wleotion  and  comjK-'tilKin  t<i 
a  hiirlicr  hUte  of  perfection  or  dominating  power,  t'laii 
the  soiitlieru  forms^.  And  thus,  when  they  hemme 
(■oii!iniiit:led  durintr  the  (ilariul  {teriod,  the  northern 
forms  were  enahled  to  l>eat  the  less  jK)werful  southern 
forms.  Just  in  the  same  manner  as  we  see  at  the 
present  day,  that  very  many  Kuroj)ean  produitioii-* 
cover  the  ^^rouud  in  Ij  I'lata,  and  in  a  le.-ser  de;rree 
m  Australia,  and  have  to  a  eertaiu  extent  beaten  the 
natives;  whereas  extremely  few  iwuthern  forms  have 
lie<oiiie  naturalised  in  any  part  of  Kurope,  though 
hi(!('-.  wool,  and  other  ohjects  likely  to  carry  si'ed- 
lia\i  lieen  lartrcly  ini|M)rted  into  Kurope  durini:  thi- 
List  two  ur  three  centuries  from  1^  I'lata,  and  during 
tiie  liL-i  thirty  or  forty  years  from  Australia.  Some- 
thiiiiT  of  the  same  kind  must  have  oeeurred  on  the 
intertroiMcal  mountains:   no  douht  l>efore  the  (Jhu-ial 

«ri<i(i  they  were  stocked  with  endemic  Alpine  fomn  ; 

ut  these  have  almost  everywhere  larfjely  yielded  to 
the  more  dominant  forms,  generated  in  the  lari>»'r 
ireas  and  more  efficient  m  rkshops  of  the  north.  In 
many  islands  the  native  prod uctioun  are  nearly  equalled 
or  eviii  outnumbered  by  the  naturalised;  and  if  tlie 
n;iti\e.s  liave  not  Inseii  actually  exterminate*!,  th»'ir 
iiunil/ers  have  Wen  greatly  reduced,  and  tlii«  is  tiie 
first  hlincc  towards  extinction.  A  mountain  Ih  an 
Island  on  the  land  ;  and  tlie  intertropical  ruountains 
l»t'fore  the  (ihuial  period  must  have  been  completely 
Isolated  ;  and  I  Lelieve  that  the  productions  of  these 
islaurjs  on  the  laud  yielded  to  those  produced  ^»  it  Inn 
•he  l.irtrer  areas  of  the  north,  just  in  the  same  way  a^ 
the  jirudut  tions  of  real  islands  have  everj-where  lately 
yHt'ltd  tu  continental  forms,  naturalised  jy  man's 
Oijeni  y. 

1  aiii  f:ir  from  suppowin^  that  all  dilficultieu  are  re- 
inoveu  on  the  view  here  civen  in  regard  to  tlte  ntu^-e 
.iiHi  aiujiii.'tis  01  the  <iiiitxi  opeties  wiiicn  iive  «u  liir 
iiorthtrii  and  southern  tem|)enite  /.onew  and  on  the 
moiiiiUiiu.-   of  the   intertropiral    re^fions.       \  ery   manr 


.■i42 


ON   THK   ORIGIN   OF   srKCIES 


I 


difficalties  rt'iiiaiii  to  Ix*  solved.  I  do  uot  jireteud  to 
iiidirate  the  exact  line8  and  meaiiH  of  miL^ratiou,  or 
the  reiison  why  certain  species  and  uot  others  have 
mitfraled  ;  why  crrtiiin  species  have  been  moditied  and 
have  ^iven  rise  to  new  j^roup''  of  form-,  and  othern 
have  remained  unaltered.  >N'o  cannot  hope  to  explain 
■iiich  facts,  until  we  can  say  why  one  species  and  not 
another  becomes  naturalised  by  man's  ag'ency  in  a 
foreitrn  lafid  ;  why  one  ranges  twice  or  thrice  aa  far, 
nT)il  is  twice  or  tlirice  a.s  common,  a.s  another  ^jjecies 
vviiiiin  their  own  homes. 

1  have  said  that  many  difficulties  remain  to  l>e  solved  : 
Mime  of  the  most  remarkable  are  stated  with  admirable 
ilearne«8  by  Dr.  Hooker  in  his  botanical  works  on  the 
antijrctic  refjions.  'Hiese  (^nnot  1)6  here  discussed.  1 
v*ill  only  say  that  as  far  as  regards  the  occurrence  of 
ideiitical  species  at  points  so  enormously  remote  a> 
Ktr^uelen  I^nd,  New  Zealand,  and  Kue^a,  I  Wlieve 
that  towards  the  close  of  the  lilacial  ptriod,  icelier^, 
as  sutrjjoated  by  Lyell,  liave  been  larjjely  concerned  iu 
their  dispersal.  But  the  existence  of  several  quite  di»- 
linct  specie.s,  lieloufrin!;  to  jjenera  exclusively  confined 
lo  t^a  south,  at  these  and  other  distant  points  of  the 
southern  hemisphere,  is,  oa  my  the<iry  of  de.scent  with 
modification,  a  far  more  remarkable  case  of  difficulty 
K(»r  soma  of  t}i*i!se  species  are  so  distinct,  that  we  can- 
not HupjK)se  tb;it  tliere  has  been  time  since  the  coni- 
inencenient  of  the  (Jlacial  period  for  their  migration, 
and  for  their  subsequent  modification  to  the  necessary 
iie<rree.  'Hie  facts  seem  to  me  to  indicate  that  peculiar 
•md  very  'iistinct  Kpecies  have  miffrated  in  radiatin^r 
lines  from  8on»e  common  centre;  and  1  am  inclined 
to  l.tok  in  the  southern,  as  in  the  northern  hemi- 
sphere, to  a  former  and  warmer  period,  before  the 
commencement  of  the  (Jlacial  period,  when  the  ant- 
arctic lands,  now  covered  with  ice,  supported  a  highly 
!>er!iliar  and  Isolated  flora.  I  suspect  that  l>efore  thi> 
flora  was  exterminated  by  the  (Ilacial  epoch,  a  few 
forms  were  widely  dispersed  to  various  points  of  the 
•aiiithern  hemtsphere  bv  occasional  means  of  transport, 


GECUiRAPHK  AL    DISTUIHrTK  >N  :^4r^ 

;iti<i  bv  the  aid,  as  haltinjf-places,  of  existine  and  now 
-unkeii  islands.  By  these  means,  an  I  l»elieve,  the 
-oiitherii  shores  of  America,  Australia,  New  Zealand, 
hav»<  l.orome  sli^^htly  tintetl  by  the  same  peculiar  forms 
of  veirt'tahle  life. 

Sir  (  .  Lyell  in  a  strikintr  pass^me  ha.s  sp«'<-tilated,  in 
l.iiiL'UHire  almost  identical  with  mine,  on  the  etfecti*  of 
iTTv.it  alternatious  of  climate  on  ideographical   distri- 
•^iiitio'i       I  believe  that  the  world  ha»  recently  felt  one 
of  his  (Treat  >  ycies  r'  change  ;  and  that  on  this  view. 
rombined  with  rnodi      ition   throujrh  natural  selection, 
.   riiiiltitude  of  facts  in  the  present  distribution  l>otl. 
.  f    the  same  nid   of  allied    forms  of  life  can    be  ex- 
plained.    The  living  watern  may  be  said  to  have  riowed 
■liirniiT  one  short  j)eriod  from  the  north  and  from  the 
,<»uth.  and    to  have  crossed    at   the  equator  ;    but  to 
•  .ave  tlowed   with  >rreat*,f  force  from  the  north  ^o  as 
'o  ii.iw  freely  inundated  the  south.     As  the  tide  leaves 
t.s  dritl  iu  horizontal  linw,  thoujfh  risin^r  hi^rher  on 
'be  shores  where  the  tide  rises  highest,  so  have  the 
tivin  '  waters  left  their  living  drift  on  our  mountain- 
-unimits,  in  a  line  jfently  rising,'  from  the  arctic  low- 
ianil-  to  a  ;rroat  height  under  the  e«|uator.    The  various 
heinsrs  tluis  left  stranded  may  l»e  compared  with  savajje 
races  of  man,  driven  up  and  surviving  in  the  mountain- 
.  vstri<:v«-es  of  almost  every  land,  which  serve  as  a  record, 
'  ill  of  interest  to  us,  of  the  former  inhabitants  of  the 
-irromidiut?  lowlands. 


1  in-" _i 


C  HAI»TKK   Ml 


f.K'KJHAPHIl  >!.    KISTIIIKITION COntilHWi 


IP 


I'istribiitl  )ii  of  frt'sh  •  w:vttr  pnvi'ptlimt  —  <>m  the  liih»l'lUnU  >( 
iMT.itiii;  iiilaiiili  —  AI>^L•lll•l•  of  IJatraihiaiiH  aiiil  of  U-rr«»tn*l 
MHiiiiiialit  On  tlic  rfliilinii  of  the  iiihaliitatiu  >■{  Islaiiils  t<> 
tliiise  of  tlif  luaii  -t  nuiiiliiiiil  -On  culonisatiiii  from  the  nrarr.-tt 
(...iircf  witli  HiiiiM'<|ueut  iiiiMliflcaUon — Huiuiiiary  of  tht-  liuti  anil 
prcsi'iit  1  Iiai>t<r8, 


I 


1*tS!' 


i 


As  lakt's  and  rivor-systerns  are  separated  from  each 
otlipr  Ity  liarriors  of  land,  it  niiyht  have  Irh'ii  tlioiiL'ht 
that  fresh -watrr  productions  would  not  hav«  raM;;ed 
widely  witliin  the  same  country,  and  as  the  «ca  jh 
ajiparently  a  still  more  impassable  barrier,  that  they 
n(n»!r  would  have  t'xtendod  to  distant  countries.  Hut 
tlie  rase  is  exactly  the  reverse.  Not  only  have  many 
fresh-water  species,  Injlong'mir  to  quite  ditTereut  clashes, 
an  fiiormous  ran^'e,  but  allied  sjM»cies  prevail  in  a 
remarkable  manner  throughout  tJie  world.  I  well 
rt^member,  when  tirst  collectinjr  in  the  friish  waters  of 
lira/il.  ietdin^  much  surprise  at  the  >iiui!arity  of  the 
fn-li-water  iiisectH,  shells,  etc.,  and  at  the  di.-v-imilarity 
of  thf  surroundiiitr  terrestrial  l>ein^s,  compared  with 
thoM>  of  MriUiiii 

Hut  tliis  power  in  fres!i-water  productions  of  rai^finiir 
widely,  thout'li  so  uiiexiK'cted,  can,  1  think,  in  most 
cases   \h\  explained   by  tlieir   liaviiiif  he4'ome   filled,   in 

--    .-,.,-  -^    1     ,,1  1 -'i-   1     t        ii r  -_      I      _»     1     r__^ 

quent  rnu^rations  from  pond  to  pond,  or  from  stream 
to  stre.iin  ;  and   liability  to  wide  dispers;il  would  bdlow 

;>44 


1    I 


GE()C;RArHI(:AL  distkibltion        .^w 


from  this  {•Apsu'.iiy  as  an  almoHt  iiwe>isary  conHe<|u«»!i<*r. 
We  ran  here  cotisider  only  a  few  cusv-*.      In   rejranl   to 
fiwh,  I  l)«lieve  that  the  same  hj>et  ie»  never  occur  in  the 
fre>h  waters  of  distant  continent*;.      IJut  on  tlie  winie 
(•(tiitinent  the  ppecie«  often   nin;?e  widely  and   almost 
c.ipririously  ;   for  two  river-systemn  will   have  some  fish 
iti  coTumon  and  s«ome  different.     A  few  facts  s«'»"m  to 
:<iv<)iir  the  ponsihility  of  their  occassional  trans})orl  hy 
;uTi4lciit;il  means;  like  that  of  the  live  fish  not  rarelv 
dropped    hy    whirlwinds  in    India,  and   the   vitality   of 
their  ova  when  removed   from   the  water.      Hut   I   am 
iiulined  to  attrihute  the  dispersal  of  frefeh-water  fish 
m  tinly  to  slight  chautres  within  the  recent  jieriod  in 
the  level  of  the  land,  havinK  caused  rivers  to  How  into 
.ii  h  other.       lustances,  alho,   could   l»e  »fiven  of  thin 
h.ivint;  occurred  during  floods,  without  any  ch.iiiue  of 
leM'l.      We  have  evidence  in  the  loess  of  the   Kliiiie  of 
runs;derai<ie  changes  ol  level  in  ihe  land  ^itiiin  a  very 
rercut  s:«'<>l<>R'*"*l   period,   and   when    the  surface   was 
pLoj.led  hy  existiujf  land  and  fresh-water  shells.      'l'h»* 
•viiie  difference  of  the  fish  on  opp4»site  sides  of  con- 
tinuous mountain-ranges,  which  from  an  early  period 
,iiu>t  have   parted   river-systems  and   completely   pre- 
vented their  inosculation,  seems  to  lead  to  this  -^aiiie 
i'on(lu>ion.       ^^'ith   respect   to  allied    fresh -water  fi>h 
occurring  at  very  distant  points  of  the  world,  no  douht 
there   are    many   case**   which    cannot   at   present    l»e 
Hvpltined  :    hut  some  fresh -water  rish   helong  t«  very 
mcieiit  forms,  and  in  such  ouses  there  will  have  U'eu 
ample  time  for  great  geographical  changes,  and  conse- 
ijUtMitly  time  and  means  for  much  migration,      la  the 
set  Olid   place,  salt-water  h>h   can  with   care  ho  slowly 
.iccwstouied  to  live  in  fresh   water  ;  and,  according  to 
\  alenciennes,  there  is  hardly  a  siuL'le  group  of  tithes 
(ontine<l  exclusively   to   fresh    water,   h4»  that   we  may 
iiiiau^me  that  a  marine  memher  of  a  fresh-water  group 
mitrht  travel  far  along  the  shores  of  the  s»>.i.  and  ^u^•s•»- 

(Ui  iitiy    r-c-coine    mouiiicd    s,:-;]    .uiiiptrd    Ui    the    ^resh 

•vaicrs  of  a  distant  land, 
.■vime  specie-s  of  fre»*h-water  nhells  have  a  very  wide 


d46 


■  "•  SH  ■ 


ON    THK   OHKJIN    Oh    SPK(  JK> 


ran^'p,  ;iiul  niliefl  .sjx'cies,  which,  orj  my  theory,  aro  de- 
H<pri(l«(l  from  a  rommoti  parpiit  aiiri'mti<t  havp  |iro- 
co.mIimI  from  a  siiitrle  source,  prevail  throturhout  the 
world.  Their  di-f rihution  at  firHt  |>erplexed  me  niurh. 
n-  their  ova  are  nut  likely  to  be  transporteil   hy  l.irdH. 

liid  tliev  are  iniUM-diately  killed  Ity  sea-water,  as  are 
tlie  adiilu*.  I  could  not  even  understand  how  some 
•1  itiiralised  s[>ecie-  have  rapidly  s|»read  throujfhout  tlie 
-ame  country,  liut  two  fact«,'  which  I  have  observed 
and  no  doubt  many  otliern  remain  to  be  observed — 
flir.iw  some  li^ht  on  this  subject.  When  a  duck 
>iiii.i<'nly  eriierjfes  Irom  a  pond  covere«l  with  duck- 
weed. I  have  twice  seen  these  little  plants  adhenny  to 
itH  l.;i<  !<  ;  and  it  has  happened  to  me,  in  rcmoviinf  J* 
little  «liick-wee(l  from  one  aquarium  to  another,  that  I 
have  <|uite  unintentionally  stocked  the  one  with  fresh- 
water Bhells  from  the  other.  Hut  another  agency  is 
perhaps  more  effectual  :  I  Buspended  a  duck's  fi'et, 
which  mitfht  represent  those  of  a  bird  §leepin^  in  a 
natural  pond,  in  an  aquarium,  where  many  ova  oi 
fresh-water  shells  were  hatchinjf ;  and  I  found  that 
numbers  of  the  extremely  minut<>  and  just-hatched 
"hells  crawled  on  the  feet,  and  dunjf  to  them  so  firmly 
that  when  t.tken  out  of  the  water  they  could  not  be 
larred  off.  though  at  a  somewhat  more  advanced  a^e 
tliev  would  voluntarily  drop  off.  Ilie-se  just  hatche<i 
rnoliusc^,  thuuirh  aquatic  in  their  nature,  survived  on 
tim  duck  s  f(.,'t,  ill  damp  air,  from  tweho  to  twenty 
hours  ;  and  in  this  leiiirth  of  time  a  duck  or  heron 
mifrht  t\y  at  least  six  or  seven  hundred  miles,  and 
would  he  sure  to  alight  on  a  pool  or  rivulet,  if  blown 
HTOS.S  sea  tr)  an  o«eanic  island  or  to  any  other  d  iiant 

•  tint.       Sir   Charles    Lyell    aUo   informs    me    that    a 
|)\-ticus    has   been    r;iu(,'ht    with   an    .\ncvlus     a   fresh 
water  shell  like  a  limpet)  tirmly  adherintr  to  it  ;  and  a 
water-beetle  of  the  same  family,  a  (  olymbetes,  once 
»lew    on     board     the     Htn'/U-     *hen     fortv-fve    miles 

liistATit    frniii    rlia    iiu:ir<iwt     l-iii<4   •     I</a<—    •»>...!.    <.'...<l :^ 

ui'ffht    have    tidwn   wii!i   a  favouring'   jn\,'   no  on«  can 


mu 


(ihCXJRAFHICAL   DISTKIHLTION 


347 


^\  ith  respect  to  plants,  it  hait  loiipf  b<'eii  known  what 
lurrnouH  ran^eit  many   tresli- water  and  even   niarsli 
pefit's  have,   both   over  continents  and    to   the   rin<»t 

•  mote  o<  eanic  islands.  Thiti  is  strikiriizly  shown,  ax 
I'Miarkt'd    by  Alph.    de  (  andoUe,   in  larife  irroupH  of 

■(•rr»'strial   plants,  which  have  only  a  very  f«'w  atjuatic 

nemhers  ;  for  these  latter  seem  immediately  to  acquire, 

i-i    it'  m    conse«|u^nce,   a    very    wide   ran^e.      I    think 

'avourahle  means  of  dispersal  explain  this  fa<'1.      I  have 

'efnre    mentioned     that    earth     occasionally,     thouifh 

'ireiy.  adheres  in  some  quantity  to  the  feet  and  heaks 

>r   birds.      Wadinu   birds,   wliich   fre(|uent  the  muddy 

.(Ijrt's   of   {M>Dds,    if   suddenly   flushed,   would    he    th» 

Tiost  likely  to  have  muddy  fret      Birds  of  this  order  I 

.m  show  are  the  (n"<**te8t  wanderer*,  and  are  occa- 

MDiially  found  on  the  most  remote  and   barren   island-* 

.  the  open  ocean  ;  they  would  not  be  likely  to  alight 

III  tiie  surface  of  the  sea,  so  that  the  dirt  would  not  U- 

•  ishvd  otf  their  feet  ;   when  makiiit;  land,  they  would 

'm'  sure  to  fly  to  their  natural  fresh-water  haunts.      I 

111  not  believe  that  botauLsta  are  aware  how  charjfed 

he  fiiud  of  ponds  is  with  seedn  :    1  have  tried  several 

lt!e  experiments,  but  will  here  ifive  only  the  mosJt 

•  •.rikiiis  fA8«  :  I  took  in  February  three  table-spooufu Is 
it'iii'.ii  from  three  different  points,  beneath  water,  on 

•  ■,,.  Hili^M'  of  a  little  pond  ;  this  mud  when  dry  wei^hcil 
iiily  t)!^  ounces  ;  I  Kept  it  covered  up  in  my  study  for 
MX  months,  pulling  up  and  counting  each  plant  as  it 
/rew  ;  the  plants  were  of  many  kinds,  and  were  alto- 
M'tiier  .">;)7  in  number;  and  yet  the  viscid  mud  wa.s 
i'i  I'oiitained  in  a  breakfast  cup  !  Considering  the?te 
:.iit>,  I  think  it  would  he  an  inexplicable  circum.stance 

*  water-birds  did  not  transport  the  seeds  of  fresh-water 
;iiants  to  vast  distances,  and  if  consequently  the  rang*- 
"f  tht^tif  plants  was  not  very  great     ITie  same  agency 

ri.iy  tuve  come  itito  play  with  the  eggs  of  some  of  the 
mailer  fre>sh-water  animals. 

<  -iiifr    ami    uukiiow:i    agencies    proiiabiy    ijave    aim 

•  '  ived  a  part.  I  have  8tate<l  that  frp^h-wat.er  ti»h  ear 
M)iiie  kintis  of  seeds,   though  they    rejert  many  other 


34}] 


ON    INK   OKKJIN    OF   8I'K{  1I':.S 


> 


kiiKls  fiaor  having  hH;ill.,we«l  tlieiii  ;    vm-u  Hmai;  Imh 
swalii.u  ^,.Hh  of  n.o«lerat«  size,  m  of  the  vellow  water- 
lily  Jiii.l  l'(.UmMtr«'toii.     IliTonsaii.l  other  hi^l^,  .riiturN 
Hitor  .eiiturv,  have  jfom.  on  daily  .ievouriu<f  fi-h;  thev 
then   take  lli>r},t  arid  jfo  to  other  waters,  or  are  hlowii 
'•.•r(.>s  the  >ea;  and  we  have  Keen  that  -.et-d*.  retain  their 
[.ower  nl   Kt-niiinatioii.  when   rejected   in   pelh-ts  ..r  in 
excrement,  many  hour-  atlerwanls.       When  1  ,s,iw 
^'leat    Hi/e    at    the    seeds    (,C   tlial    tine    waU-r-lilv,  the 
NelumhiMin,    ami     reinerni.ered     .\!i,h.   de    (  andolles 
remarK-   on  thii,  plant,  I    thought     Lt  it*  di>trihijtion 
iniiM    remain  .|uite  inexplicahle  ;    hut  v^uduhon   Mate^ 
that  he   found   tho  Keedn   el   the  creat  southern  nater- 
ily   i.rohahly.a.Twrdintjto  Dr.  Hooker,  tlie  Nelumhiun. 
Iiitetim)  m  a  heron'n  wlomach  ;  althoujfli  1  do  not  kiiov* 
the  taet,  yet  analo^jy  makes   me  U«lievo  that  a  lieron 
tl\mt;  to  another  iK)nd  and  ^ettin^f  a  hearty  meal  >^t 
tisli.  won  hi  i.rolwihly  reject  from  it«  stomaih  a  pellet 
■■onUinuiK  the  seeds  of    the  Nelumhium  undi4fe^ted  ; 
'r    the    heedH    mi^ht    U-    dropped    hy  tlie  hinl  whilst 
leedinu'   il.s  younjr,  in  the  same  way  a^  hsL  are  known 
somelimeh  to  l»e  drop|,ed. 

In  eonsiderin^  thf>e  several  me.'ins  of  distri.,^tion, 
It  should  !»#»  rememhered   that  when  a  pond  or  streani 
IS  first  formed,  tor  instance,  ou  a  rising  i^let,  it  will  he 
iMUKVupie.1;  and  a  sin^rle  Mjad  or  e«:jr  will  have  a  ^'ood 
ehaiice  .,1  sueceeilin^r.     AithouKh  there  will  alwavs  he  a 
stniiryle  (or  life  Imtween  the  individuals  of  tlie  specie-, 
however  few,  already  oceupviu^  any  pond,  vet  as  the 
miinl>er  of  kinds  is  small,  compareil'with  those  on  the 
and,   the    oomi)etition    will    proh.ihlv    1^    less   severe 
l>etweeii  aquatic  than  hetween  terrestrial  sj>e<i.-s  ;   con- 
sequently an  intruder  from   the  waters  of  a    foreign 
country,  would  ijave  a  hetter  chance  <.f  seizing  on  a 
place,   than  in  the  rase  of  terrestrial  colonists.       We 
sliould.aLio,  rememher  that  some,  perhaps  many,  fresh- 
water productions  are  h.w  in  the  scale  of  nature,  and 
th.it  we   have  reason  Ut  lieljeie   iliat   si-ch   !(>.u-   h;  i;-— - 
chan^n-  or  become  modiiied  less  .juickly  than  the  h^'h  ; 
and  this  will  tive  lonj^er  time  than  thi'  uverd^^e  for  the 


(;K(K;HAPmcAL  DisnumrnoN 


341> 


mitfTatJon  of  the  nam^  aquatic  «p«>ri«»n.  W'v  shotil<l  not 
•'(.r^'ot  the  pruh.ihility  of  many  sp^rips  h.ivini^  foriiu'rlv 
'iiiiffvl  an  continuously  as  fresh-wnter  prjwluctionH  ev»«r 
-111  raiure,  over  immpiis*  areas,  ami  havinjf  suhsoijui'nHv 
•♦•(•omo  extinct  in  internie<liate  rejfions.  But  the  wide 
i>tril)iitinn  ot  f re* h  -  water  [ilantx  ami  of  tin*  lii»«'i 
iiiimals,  whether  retiinitiif  tlie  same  identical  (■  'n 
<r  ill  ^ome  fleirree  modifieii,  I  believe  mairilv  de|»eiids 
•  i  the  wide  dispersal  of  their  «eeds  and  etrirs  iiy  aiiirnaU, 
imrt*  cHpetMally  hy  fresh-water  hirils,  which  h.ue  larifc 
lowiTs  of  tliiflit,  aiui  naturally  travel  f  m  one  to 
..'luthcr  and  often  distant  piece  of  water.  \  «*urf,  like 
I  r.ireful  ifardener,  thus  takes  her  seeds  from  a  UmI  of 
1  piirticiilar  nature,  and  drops  them  in  anoth»>r  e<)uall\ 
^♦•ll  fitted  for  them. 


"a    ihf    Ifihahitnntfi    of  Orranie    lulnn-ix.  —  We    now 

•lime  til  the  la^t  of  the  three  cla».«e?*  ot   facts,  which  I 

i.ive    selected    as    presentinjf    the  tfreatest  amoiuit  «)f 

■i.fticulty,  on  the  view  that  all  the  inilividua  -  Inith  of 

•'le  vinio  and  of  allied  species  have  descended  from  u 

iiiL'le  jkarent  ;  and  therefore  have  all  proceeded  from  a 

■  iiiimon  birthplace,  notwithstandinif  that  in  the  course 

'  time  they  have  come  to  inhabit  distant  {Ktint.s  of  the 

.'liilie.      I    have  already  stated   that  1  cannot    honextiy 

ulmit   Forben's  view  on  continental  extensions,  whicli, 

:;   iejjitimately  followed  out,  would  lead   to  the   ixlief 

•I  It  witliin  the  recent  periml  all  existing  islands  liave 

't  eii   nearly  or  quite  joined  to  some  continent.      This 

>'w  would  remove  many  difficultien,  but  it  would  not, 

tliink,  exphain  all  the  factn  in  retrard  to  insular  pro- 

tiutioris.     In  the  followine  remark.s  I  shall  not  contine 

ii\Mlf  to  the  mere   question    of   disper-al  ;   but  shall 

.  nii.siiier  some  other  factii,   which  l>e^ar  on  the  truth  of 

'K.'  twd  theories  of  independent  creation  and  of  descent 

*  "ti  iiiodiJication. 

Hie  ■.jiecies  of  all  kinds  which  inhabit  oceanic  islandit 
■••c"  .1  *•*•  111  4a««iii[K  r  ;  urii litirtii  '"^iiii  i-iio""**  on  •  tiwrii  I'^in- 
lifUMit.Tl  areas:  Alph.  de  ("andoUe  admits  this  for  planta, 
■i!ii    WoUaston  for  insectH.       If  we  look   to  the  larg^f- 


fW) 


ON    illK   OKKilN    OK   M'K(  IF> 


'i\ 


I 


i' 


sIm!  and  varied  •*tatiniiH  «tf  New  /ealaiid,  <'xt«Mi(liii>f  own 
7ttO  mill's  til  latitude,  and  fompart'  itn  fl«»weriii:-'  plants, 
nnlv  T-'"  in  nuinlicr.  with  thiixe  on  an  etpial  area  a? 
tiip  (ape  of  (Jood  Hope  or  in  Australia,  we  rrnist,  1 
think,  admit  that  iMtmethintr  <|iiite  inde{M'nd<Mitly  of 
iMV  difference  in  physical  ••()niiitif)nH  has  raiise<i  st»  pr'-a* 
I  difference  in  iinniher.  Kven  tl>e  uniform  county  of 
•  .iiiiliridtre  ha^  H47  plaiitfl,  and  the  little  island  ot 
\ii4rle«ea  7'>4,  hut  a  few  ferns  and  a  few  introduced 
i>lant.s  are  included  in  these  numhers,  and  the  cuiii- 
pariHun  in  Home  other  respect*  is  not  quite  fair.  We 
iiave  evidence  tliat  the  harreti  inland  of  Asi-ension  ai»- 
"irig-inally  nossessed  under  half  a  dozen  Howerinir  plant*; 
\et  many  have  become  naturalixed  on  it,  as  they  have 
in  .Now  Ze.-iland  and  on  every  other  oceanic  island 
vhi'h  can  he  named.  In  St.  Helena  there  in  rea.son  to 
l>elieve  that  the  naturalised  plants  and  animals  have 
nearly  or  quite  extermii:r.*.;'d  many  native  productions 
lie  who  admits  the  doctrine  of  the  creation  of  each 
-eparale  species,  will  have  to  admit,  that  a  suffit'ient 
iiumher  of  the  best  adapted  plants  and  animals  have 
not  Iwen  created  on  oceanic  islands  ;  for  man  has  un- 
iiiteiiti(»nally  stocked  them  from  various  gof.rces  I'ai 
more  fully  and  |>erfcctly  tlian  has  uature. 

Althoutrh  in  uceaDic  islands  the  number  of  kindd 
■  >f  inhaliiLants  is  scanty,  the  proportion  of  endemic 
species  {i  r.  those  found  nowhere  else  in  the  world)  is 
often  extremely  lar^e.  If  we  compare,  for  instance, 
the  nuHiher  of  the  endemic  land-shells  in  Madeira,  or 
of  the  endemic  birds  in  the  Cialapagos  Archipelago, with 
the  number  found  on  any  continent,  and  then  compare 
the  area  of  the  islands  with  that  of  the  continent,  ^e 
>.hall  see  that  this  is  true.  This  fact  mi^ht  have  \>eeu 
expected  on  my  theory,  for,  as  already  explained, 
species  occasionallyarnvin^  after  lou^  intervals  iti  a  new 
and  isolated  di.strict,  and  havin^f  to  comi>ete  with  new 
asso<';ate*,  will  he  eminently  liable  to  modification,  and 
•-ill  '-({e-ii  j-ro-iiicc -jTO"}'- of  modified  dcsi'ondant?;.  Hn% 
it  by  no  means  follows,  that,  because  in  an  island  nearly 
all  the  specieji  of  one  class  nre  peculiar,  those  of  another 


(iK«H;iiAI'HI<  Al.    DIS'lKiHl HON 


:i5i 


.ami,    -ir   of    aimlliir    sertion    ot    the    winu*   «;l;.>-.    nrv 

jn'ciiliar  ;  and  tliin  diffrrfru  ••  M>ems  to  (ir|)«Ti(l  itaitlv  iti 

'ho    i«;><>t-ic.s    which    «t«»    not     h«M-om«'    nioiiitiiMi    having 

rnrniirratrd  with   f;icility  and   in  a  JkmIv,  bo  that  tlicir 

iiiitu.il   rrlatioiis  have  not  heeu  much  'diMturU.!  ;  ;inil 

•  artly  un  tlif  frt'cjucnt  arrival  of  iiriniodifuMl  inunik'r.iiiN 
itm  the  niotlnT-coiintry,   and   tJie   c«)nKe»|u»-iit  iiitor- 

(  r<i>»sin^  with  thorn.    >N'ith  r«w|ie<  t  to  the  offrrt-  ot  thi^ 
iiittTfrossint;,  it  should  Im>  ri'Mu-niln'rol  that  the  orf-prini: 

•  •f  surh  croHses  would  almost  cert-iinly  gAxii  in  vi^'our  ; 
»<•  tliat  even  an  oc«asional  itoks  would  prcMluce  more 
n'.rt  tlian  miirlit  at  lirst  have  l»een  anticipated.  I'o  jfivc 
I  t.'W  examples  :  in  the  (ialap.iiroH  Isl.nida  nearly  ev«T\ 
l.iiid-hird,  hut  only  two  out  ot  the  eleven  marine  hirds. 
ir»>  peculiar  ;  and  it  is  ohvioiis  that  marine  hirdg  could 
irrivf  at  these  i.^iandH  more  easily  than  land  -  l»ird«». 
Uermtida,  on  the  other  hand,  which  lies  at  alxiut  the 
■iiiie  distance  from  North  America  an  the  (lalapairo-^ 
l-laiids  do  from  South  America,  and  which  h:w  a  very 
peculiar  soil,  does  not  ponsens  one  endemic  land->>ird 
iiid  we  know  from  Mr,  J,  M.  Jon«»'K  admirahle  ac,  ount 
-f  Bermuda,  that  very  many  North  American  hird-. 
Iiiririj;  their  jjreat  annual  mijrrations,  vinit  either 
[••Tii.dic.illy  or  occasionally  thin  inland.      .Maiieira  d(K>«i 

"t  possen."  one  peculiar  bird,  and  many  European  aim 

African   birds  are  alirost  everv  year  blown  there,  as  I 

im  informed  by  Mr.    K.   V.   ifarcourt      So  that  these 

two  islands  of  Bermuda  and  Madeira  have  been  stm-ked 

I'V  birds,  which  for  loujf  a^es  have  strujfjjled  topetiier 

111    their    former  homes,   and    have  l)efome    mutually 

idapied  to  each  other  ;  and  when  settled  in  their  new 

""lie-,  each  kind  will  have  l>eeu  kept  by  the  others  to 

I'cir  proper  place.s  and  habits,  ami  wril'l  consequently 

:  tve  been  little  liable  to  nuKJificatiou.   Any  ten<ieiic\ 

t"  niodification  will,  also,  have  l»een  checked   by  inter- 

croosinu    with    the    unmodified    immijjrants    from   the 

niotiior-country.      .Madeira,  a^ain,    is    inhabited    by  ,t 

;;;.tTiUi  .iii,ni)er  or  peculiar  ianii-sheii.t,  ♦*iier»i»  not 

one  species  of  sea-shell  is  confined  to  it*  shores  :   now, 

thoujfli  we  do  not  know  how  sea-«hells  are  di«|>ers©d,  yet 


■f^S^iSBs. 


LV>2 


ON   THK   ORIGIN    OF   SPECIKS 


I 


m 


wp  ran  see  that  their  p^jtm  or  larva*,  [K'rhaps  attached 
In  M^awoed  or  lloaiiiijf  timher,  or  to  the  feet  of  wadiiur 
hini*;,  mitfht  bo  transjMirtcd  far  more  easily  th^in  laud- 
-hoU-i.  across  throe  or  four  hundred  miles  of  (.jh"!!  sea. 
1  he  dirierjiit  orders  of  inseotw  in  Madeira  apparently 
[irc<ciit  ariali.tr"'is  fa<'ts. 

( li'cani*;  islands  are  Homelimes  deficient  in  certain 
clasM'-;,  and  tS'^ir  places  are  apparently  occupied  hy 
the  otlicr  iiili.iliitanl-s ;  in  the  <ialapacos  Islands  reptiles, 
and  in  New  Zealand  ^'•i^'nntic  wiriffless  birds,  take  the 
place  of  mammals.  in  tlie  plants  of  the  (ialapa^os 
l-l;ind»*  Dr.  Hooker  has  shown  that  the  pro{K)rtional 
nnml^ors  of  tlie  different  orders  are  very  dirferent  from 
iviiat  they  are  elsewtiere.  Such  i-aso  are  generally 
iccouutcd  for  by  the  physical  cctnditions  of  the  islands  ; 
t)ul  tins  exphin.ition  seems  to  me  not  a  little  doubtful. 
Kacilitv  of  immiirration,  I  believe,  has  been  at  least  aj* 
iriiiKirtant  as  tlie  nature  of  the  conditions. 

Many  remarkable  little  facts  could  l>e  iriveu  with 
re-pect  to  the  inliabitants  of  remote  i»l.iniis.  For 
in-tance,  in  i-ertinn  islands  not  tenante<i  by  mammals, 
some  of  the  endemic  plants  have  beautifully  tiooked 
seeds  ;  vet  few  relations  are  more  strikniir  tlian  the 
adaptation  of  t,'<)ked  seeds  for  transportal  by  the  wool 
•nil  fur  of  ijuadrupeds.  lliis  case  presents  nr*  difficulty 
0:1  ;nv  view,  for  a  liooked  seed  mijrht  l)e  trans[)orted  to 
Hi  island  bv  some  nthe,"  means;  and  the  plant  then 
.>e<"iim:nir  slitrhth  modilied,  but  still  retainiiiir  its  hooked 
«ec'i>.  vMiiild  fiirm  an  endemic  s[)ecie».  having-  a-«  useless 
•iu  appendaire  as  any  rudimentary  ort^in,  tor  instance, 
as  tlie  shrivelled  wintrs  utiiler  the  soldered  elytra  of 
many  insular  beetles.  .Atrain,  islaiuls  often  jxtssess  treen 
or  bu<hes  >ielont''intr  to  orders  whi«h  elsewhere  include 
onlv  herbaceous  s(»ecies  ;  now  trees,  as  Alph.  de 
I  aiiilolle  has  sliown,  trenerallv  hav  e,  wiiatever  tlie  cause 
mav  be,  contined  rauire-i-  Hence  trees  would  be  iittle 
likelv  to  reaeh  distant  oceanic  islands  ;  and  an  herb- 
.•  eou-  pi  ml.  liiotiiiij  it  woiiiO  navt-  in)  criaiiCti  of 
»iicces>tullv  lompetiiiT  in  stature  with  a  fully  de- 
vt>jnTH'd  tresv  when  esfaMisheu  on  an  inland   a.ud  havinc 


GE(XiIU  ^MICAL   DISTRIBUTION 


•A.V\ 


to  compete  will.  -  \aceuus  plunls  aloiie^  nii^flit  rf^dily 
train  an  advant  Uy  jrrowiug   taller   and  taller  and 

uvortopiiin^  the  •  tlu-r  |)lants.  If  so,  natural  »ele<fion 
Hoiild  often  tend  d  add  to  the  stature  of  herbaceous 
plants  wlien  <rrowiiiir  on  an  ocean-c  island,  to  whatever 
iirder  tlu-y  ht'loiiifcd,  and  thus  convert  them  first  into 
hu>hes  and  ultimalfiy  into  treefi. 

^^  itli  n"^pect  to  the  ah>ience  of  whole  orders  <iii 
fxeauic  inlands,  Hory  St.  Vincent  lon^  ago  remarked 
that  Balrachians  (fro^s,  toads,  newt^)  liavo  never  hecn 
found  on  any  of  tlie  many  i-laii<U  with  whidi  the  frrcat 
oceans  are  sttidiifd.  I  have  taken  pains  Ly  veritv  this 
assertion,  and  I  have  found  it  strictly  true.  I  have, 
however,  heen  a>sured  that  a  fro;;  exists  on  the  moun- 
tains of  the  i^reat  inland  of  .New  Zealand  ;  hut  I  suspect 
ttiat  this  exception  (if  the  ini-  •  'ation  ho  correct)  may 
'•e  explained  throuirh  ^'lacial  agency.  Ihis  ^MMieral 
ih>eiice  of  frog^s,  toads,  and  newts  on  so  many  oceanic 
-lafiils  cannot  lie  ai-couiitcd  for  hy  their  physical  con- 
iitioiis  ;  indeed  it  seems  that  islands  arc  peculiarly  well 
titted  for  these  animals  ;  for  fro^s  have  heen  introduced 
into  .Madeira,  the  .Vzores,  and  Mauritius,  and  have 
Multiplied  <()  as  to  i>ecome  a  nuisance.  But  as  these 
iiiimals  and  tlicir  spawn  are  known  to  he  immediately 
'  illed  hy  sea-waU-r,  on  my  view  we  can  see  that  there 
■vould  Ite  threat  difficulty  in  their  tran.«jK)rt:il  across 
'he  sea,  and  therefore  why  they  do  not  exi.st  on  any 
oceanic  island.  But  why,  on  the  theory  of  creation, 
ihey  slioiild  not  have  l)een  credited  there,  it  would  he 
very  didicult  to  explain. 

.Mainmals  o'!ei  aimther  and  similar  ca.se.  I  havf 
'•arefnlly  searched  the  oldest  voyages,  hut  have  not 
tinivhed  my  search  ;  a.s  yet  I  have  not  found  a  single 
iiistitriie,  free  from  doubt,  of  a  terrestrial  mammal 
(excluuing  domesticated  animals  kept  hy  the  natives) 
iiihahititiL'  an  island  situated  aUive  ti<H>  miles  fron>  a 
continent  or  great  continental  islaud  ;  and  many  inlands 
situated  at  a  much  le«o  distance  are  e»)ually  barren, 
i  he  lalkland  Ishand8,  which  are  inliabited  f>\  a  wolf- 
like  fo\,  come  nearest  to  an  exception  ;  hut  this  trroup 


364 


ON  THE  ORIGIN  OF  SPECIES 


cannot  be  considered  as  oceanic,  ii«  it  lie«  on  a  bank 
connected  with  the  mainland  ;  moreover,  icelterjfs  ror- 
iiierly  broujjht  boulders  to  its  we«tern  shores,  and  they 
may  have  formerly  transported  foxes,  as  so  frequently 
now  happens  in  the  arctic  re>)^ions.  Yet  it  cannot  be 
H;iid  that  small  islands  will  not  support  small  mammals, 
for  they  occur  in  many  parts  of  the  world  on  very 
Hmall  islands,  if  close  to  a  continent  ;  and  hardly  an 
island  can  be  named  on  which  our  smaller  <)uadrupeds 
liave  not  become  naturalised  and  greatly  r  lultipfied. 
It  cannot  be  s;iid.  on  the  ordinary  view  of  cre-atiou, 
that  there  has  not  been  time  for  the  creation  of  mam- 
mals ;  many  volcanic  islands  are  sufficiently  ancient, 
as  shown  hy  the  stupendous  deyrradation  which  tliey 
have  siitfere^l  and  by  their  tertiary  strata:  there  has 
al>;o  been  time  for  the  producti<)n  of  endemic  species 
heloiitrin^  to  other  classes  ;  and  on  continents  it  is 
thoujfht  that  mammals  apjwar  and  disappear  at  a 
<j nicker  rate  than  other  and  lower  animals,  'iliou^h 
ti'rre>trial  mainnui.s  do  not  occur  on  oceanic  islands, 
atrial  iiammals  do  occur  on  almost  every  island.  New 
Zealand  possesses  two  bat«  found  nowhere  else  in  tlie 
world  :  Norfolk  island,  the  Viti  Archipelago,  the  Honin 
i.-laiids,  the  Caroline  and  Marianne  Archipehi^oes,  and 
Mauritius,  all  po>sess  their  peculiar  l»ats.  \V'hy,  it 
may  be  asked,  has  the  supposed  cre^itive  force  prf>- 
(liiced  bats  and  no  other  mammals  on  remote  islands? 
( »a  my  view  this  question  can  easily  lie  answered  ;  for 
no  terre-tnal  mammal  can  he  trans{M»rted  across  a  wide 
-l>ace  of  sea,  but  kats  can  fly  a<-ross.  liats  have  been 
M'eti  wanderintr  hy  day  far  over  the  Atlantic  <  )i  ean  ; 
aiui  two  .\orth  American  specie-*  either  rcirulariy  or 
occasionally  visit  IJermuda,  at  the  distance  of  «;(K>  miles 
trom  the  mainland.  1  hear  from  Mr.  iomes,  wh»t  has 
specially  stmiied  this  family,  that  many  of  the  same 
sjiecies  have  enormous  ran^^es,  and  are  found  on  conti- 
nents and  on  far  distant  island*.      Hence  we  have  onlv 


TTaJiurr:;;^ 


tie>d  through  natural  selection  iii  their  new  hoinee  in  re- 
lation to  their  new  position,  and  we  cjui  understand  the 


GEOGRAPHICAL   DISTRIBl  TION         365 

pr«^«'nce  of  endemic  bat«  on  islands,  witli  the  altsence 
of  all  terrestrial  mammals. 

i{eside.s  the  ahsence  of  terr.'strial  mammals  in  rela- 
Uou   to    the    ri'motencH*   of   islands    from    contiiuTits 
ilwro  18  also  a  n-lation,  to  a  certain  ext.-nt  indoi.pn(lent 
of   distanre,  between  the  depth  of  the  ^ea  m-iKtratiinr 
an    island    from   the   nei^rhbourinjf   mainland,   and    the 
{.reHence  in  lK)th  of  the  same  mammiferoiis  species  or 
of  allied  speci.-«  in  a  more  «.r  less  modified  condition 
Mr.  U  md>or  I':arl  has  made  s«mie  strikintr  ol.servati<.iH 
ou  thiH  head  in  reirar.l  to  the  crea'  Malav  ArchiH«ir.. 
vihich   IS   traversed    near   fciche^    by  a   space   of  d.^p 
•  •<  ean  :   and    this  «pa«e  separate*  two   widelv   distinct 
mammalian   faunas.      On    either    side    the   i.sland^  are 
sitiia'od    on    moderately   deep    submarine    banks,   an.l 
theyaro  inhabited  by  closely  allied  or  identical  ,|ij;id- 
r.ijM.iv      No  doubt  some  few  anomalies  o«cur  in   tliis 
irrcat  archipelairo,  and  there  is  much  difficulty  in  form- 
intf  a  judu'ment  in  some  ca.ses  owintf  to  th.-  proUibl.. 
naturalisation    of    certain     mammals     throuirh     man'- 
;.;:ciiry;  J.ut   we  shall   soon   have  much  liirht  thrown 
"u    tlie    natural    history    of    this    anbipolaifo    by    tlic 
admirable  zeal  and  researches  of  .Mr.  Wallace.      I  ha\e 
liol  a.s  yet    had   time  to   follow    up  this  subject   in  all 
••;bcr  .juarters  of  the  world  ;   but  as  far  a.s  i  have  iroue 
tic   relation   generally   h.dds    g,uu\.      We  see    Mnf.un 
sej.arat.d   by  a  shallow  .•harinel  from    Kurop-.  and   the 
Tii.immals  are  the  same  on  both  sides  ;  we  meet  with 
ai.al..^M.us   ♦•actf'  on   many  islands  .sep;,rated   by  similar 
ci.inneN    from   Australia.      The    \\  est    Indian'    M;..h|s 
stand  ..n  a  deej.ly  submertred  bank,  nearly  1<hk»  fathoms 
111   depth,  and   here   we   hnd    American   forms,  but  the 
-Irenes   and    even    the    jrenera    are    distirnt.       As    the 
am. Mint  of  modification  in  all  ca.ses  dein-nds  to  a  certain 
<Ui:ri'e  im    the  lapse  of  time,   and  a^  durin-  rha.-es 
Of  Jevp    ,t  IS  cbvmus  that  islands  separated  by  s}i;,ll«,w 
<  banriel.s  are  more   likely   to   ha.e   l,een   contioMnuJv 
'"..leji   wiuiin  a  recent   {H>nud    U>.   the   mainland   than 
islands  separated   by  deejn-r  cf-  .nuel^.    we   can   under 
-tand  the  fre.pient  relation  1  •.ween  the  depth  of  tJi« 


366 


ON   THE  OllKJIN   OF   SPEC  IBS 


tea  and  tin  ile^^n;-  of  affiuityot  the  mnmmalian  inhaujt- 
iiit>.  of  isl.iii'ls  w;  h  tlios«  of  a  neiphl>ouriii)i?  '-oiitinerit, 
-  ,-iti  iiio.\iili<altle  r..I;iti()n  on  the  view  of  mdepen<ieiit 

;,c1ri  i)t   iT«'ati()ll. 

All  the  l(in'i.'Oiiiif  retnark^  on  Cue  iuhahitanljH  ot 
o.-.'.ini<  i<l.tii<l>.  ii:im<ly,  liie  «'carcity  of  kiuds-tlie 
richness  in  t';i'i''nHr  tonus  in  partifular  claS!4«-<  or 
«e«-tion>  of  clas-*'-.  the  ahM'n.e  of  whole  irroups.  a«  ot 
!(atr:u-lii.t)i-.  and  ot  lerrt-Ntrial  mammals  notwithstand- 
ing: the  |M.-.eii.-e  .>f  a.-rial  hats,  the  sin^'ular  projior- 
i.iMii^  of  ■rrt.tin  nr<i.rs  of  plants,  herhaceouH  ft>rins 
iiavMi?  heeii  deveiope<i  into  trees,  ete.,-  s(«em  to  me 
to  ae.i-oro  hetUT  with  Uie  view  of  occasional  means 
of  tr:'!isi»(irl  liavini;  hecii  r.r-ely  ellicient  iu  the  lon*j 
course  of  liruo,  tlian  with  tin'  view  of  all  our  oceanic 
islands  havintr  ''•'•'ii  furmerl)  lOinuKled  lt>  contniuous 
land  with  the  nearest  continent;  for  ou  this  latter 
view  tlic  iiiiirration  would  prol'ahiy  have  he»'n  more 
I  (.iiipiete  ;  and  if  inoditication  he  adinilteii,  all  the  tnrins 
»f  life  Aiiuld  have  U>en  more  ei|t;ally  ino.litied,  in 
ic<-ord:i!ice  with  tiie  j>aramount  imporUnc-  of  the  rela- 
tion of  orL'aiii-tn  to  orii-anisin. 

I  do  not  'leiiv  that  there  are  niaii}'  and  jrr^^'e  diffi- 
culties in  understindina:  how  several  of  the  inhabit-int.> 
of  the  more  rein.ite  i>land-.  wliether  still  retaining  the 
same  specific  form  or  moditied  .since  their  arrival,  ''•"Id 
;ia\  e  reached  their  present  homes.  Uut  the  prol»abiiity 
of  iiianv  i>land-  havinir  existed  am  haUiiitj-places,  of 
which  not  a  wreck  now  remains,  mu-L  not  l>e  over- 
looked 1  will  here  trive  a  single  instance  of  one  of 
the  ca-es  of  ditK. ulty.  .\lmo>t  ali  oceanic  islands, 
even  the  most  i.solated  a'.d  smalleht,  are  inhabited  by 
hinii  >hells,  trenorally  i-y  endenuc  species,  hut  some- 
'ime-<  iiy  sp,M•ie^  found  ei>ewiiere.  Dr.  Auir.  A.  tiould 
has  ifiveti  several  intere^liiijr  cases  in  re-ard  to  the 
land-shells  of  the  i-latids  of  the  I'acilic.  Now  it  is 
noL.'-iotis  that  land->liells  are  verv  easil>  killed  by  salt  , 
I'leir  ezir>.  at  iea."<t  "-ti'  ii  as  i  na'>c  iric';,  siiiii  :;;  r.ca- 
vsater  and  are  killed  hy  it.  Vet  there  must  he.  on 
Miv   view,  some    unknown,   i>ut  hi;;lily  efficient   uieani 


(;Kf>r,RAPHirAL  nisTRiBrrioN 


.%- 


f 


for  their  traii«,>ortHi  U'ouhl  the  just-liatched  y«itiiit£ 
urrnsiniially  •nvw!  uti  hud  adhere  to  the  tVet  of  hird- 
roostiutf  on  tlie  ^rnmri!,  and  thus  get  transported?  It 
.)r('iirrt'«l  to  nie  that  land-shells,  when  hihjTiiatiiiu'  and 
*iaving  a  nifmhranout  diajdirayrn  o\er  tl**  mouth  o' 
ihe  shell,  niinht  he  tlnnted  in  rhuikc  of  drifted  tiiuher 
\cr(tsx  nuM^er.i  'ly  wide  arms  of  the  sea.  And  1  toiiini 
that  (several  s{>*M-ifH  di  '  in  'is  state  withstand  un- 
inj  ired  an  immersion  ii.  sea-nater  durinj:  lieven  days  : 
01. »•  id  these  shells  was  the  Helix  pomatia.  and  after 
it.  had  a^Tiin  hibernated  I  put  it  in  sea-water  for  twenty 
days,  and  it  [  ^■rfei  tly  reeovered.  As  thi-.  -pofies  ha.n 
a  thick  caloar  uus  open  !> him.  I  removed  it,  and  when 
It  had  formed  a  new  mi  nhr;,  lous  one,  I  immersed  it 
^or  toii  -en  days  in  sea-water,  and  it  recovered  and 
•  rawle':  .^ay  :  hue  more  experiments  -ire  wanted  on 
tills  ht.»d. 

The  mo.-t  stnkintr  and  import.i'it  fart  for  iis  in  re-.ird 
to  tlie  inhabitants  of  islands,  i.s  their  affinitv  to  those  o! 
liie  ...'are-t  iiuinlaml,  without  heinir  aetualh  the  same 
-p»'ties.  Numerous  instance.-  could  he  (ri\en  of  this 
fact.  I  will  tnve  "hly  one,  that  of  the  'ialapajjo- 
Archipelago,  situated  under  the  e<iuator,  between  ;>'" 
..nd  r,iM)  miles  frnip  ^he  shores  of  South  America. 
M'T.-  aimoi<t  every  product  of  the  land  and  water  Wars 
tl.e  1  niiiistakahle  stamn  of  the  Amerir.m  eontment. 
I  here  are  twenty-sit  land-hirds  a'd  twentv-rive  ot 
these  are  r;i::ked  hy  >tr.  <  Jould  a  distiint  species, 
supposed  to  have  heen  created  here  ;  vet  the  clofie 
rtdinity  of  most  of  tiiese  b'rds  to  Aoierican  species  in 
f'verv  character,  in  their  hai)it.s,  restures.  and  toties  of 
■  c( ,  '.vari  manifesit.  So  it  is  »:th  the  ottor  animals, 
and  with  nearly  all  the  plants,  as  shown  hv  l>r  Hon'  r 
'H  h\->  adii'.iralde  memoir  on  the  Flora  c?  this  ar-di;- 
P'dajo.  'I'he  naturalist,  lookint'  at  the  inhnbitanLs  of 
these  volcanic  islands  in  the  Pacific,  disUmt  se.  eral 
tuiuilrfsl  miles  from  the  tontinent,  vet  leeK  that  he 
s  sUndiniT  on  Amencai:  land.  Why  should  this  b*- 
s-.f*  wbv  should  tlie  species  which  are  supposed  U> 
;..iTt    (m'^i)    freate<l    in   the  (Jal.ioaeos    Ar<hipel.iii((,  and 


368 


ON    THE   ORIGIN   OF   SPECIKS 


»    ! 


-4i 


II 


iiowhere  else,  J.ear  so  pl.iin  a  «timp  of  affinity  to  th.>H« 
creatoil    in    Am.'rirfl  -      Jliere   is   nothing   in   the  con- 
ditioriH  of  life,  in  the  ireoloKiral  nature  of  the  islan.in, 
in   thiMr   heitrht  or  climate,  or  in   the  proportions  in 
which  the  several  clast^eH  are  awociated  toirether,  whirh 
rPM'nii.l.'H  closely  the  roiulitions  of  the  South  Am.rican 
coast  :  in  fact  there  is  a  consiilcrahle  dissimilarity  in 
■ill  th.->-e  rcspecu.      ( >n  the  other  hand,  there  is  a  con- 
sidcrahle  decree  of  ^esemh^.!H•e  in  the  volcanic  nature 
of  the  soil,  in  climate,  height,  and  si?^  of  the  islands, 
l)etw(>entlie(;al,Ti.,'i:rosaii(|  (  apede  \erde  ArchijK'ht^ros  : 
hut   what    an   entire  and   a'«soiuto   difference   in    their 
inlial-itvirits  :     11,.'   inhahitants  of  the  (  ajw  df  Verio 
lsl,li|(J^  are  rolate.l  ^o  those  of  Africa,  like  tho^e  of  t'le 
(iai.ipacos  to  Amerira.      I  helieve  this  errand  fact  can 
receive  no  sort  of  exjilaiiation  on  th.>  ordinary  view  nf 
in(i."p..rident  creation  ;  whereas-  on  the  view  here  main 
Uiiicd,  it  is  obvious  that  the  (laiapa^os  Mands  won!.' 
he   likely  to   receive  colonists,  wliether  hy  occahional 
means  ol  transport   or   hy   formerly   continuous   land 
from  America;    and   the  Cape  de  Verde  Islands  from 
Atrica;    and    that    Puch    colonists   would    he   lia'de   to 
modification  ;-the  principle  of  inheritance  still  lietray- 
inj;  their  firiffinal  hirthplace. 

Many  analo;rou8  facts  could  l»e  eiven  :  indeed  it  is  an 
almost  universal  rule  that  the  endemic  productions  of 
islands  are  related  to  those  of  the  nearest  continent,  or 
of  other  near  islands.  'ITie  exceptions  are  few,  and 
nio>t  of  them  can  be  explained.  'Hius  the  plants  of 
Kcrffuelcii  Und,  thoii;:h  standing:  nearer  to  Afriia  than 
to  America,  are  related,  and  that  very  closelv,  as  we 
know  from  Dr.  Hooker's  account,  to  those  of  America  • 
hul  on  the  view  that  this  island  has  heen  mainly  stocked 
hy  seeds  broug-ht  with  earth  and  stones  on  "iceher-s, 
driited  !.y  the  prevailiner  currents,  this  anomaly  dV 
Tpix'ars.  New  /eiland  in  its  endemic  plants  is  much 
more  closely  related  to  Australia,  the  nearest  mainland, 
than  to  any  other  reirion  :  and  t!ii»  i-  wliat  mi-'ht  b-.v^ 
(►een  e.vi>ected  ;  hut  it  i«  also  plainly  related  to  South 
Am.-nca,  winch,  althoueh  tiie  next   nearest  continent, 


-fii,. 


GEOGRAPHICAL   DISTRIBUTION 


3A9 


\n  no  enormously  remote,  tliat  the  fact  beromt^  an 
.inomaly.  Hut  thif  difficulty  almcmt  disappears  on  the 
view  that  l>oth  New  Zealand,  South  America,  and 
other  southern  lands  were  Ions:  a^o  partially  (itocke<l 
tVom  a  nearly  intermediate  though  distant  point,  namely 
from  the  antarctic  islands,  when  they  wore  clotlie<l  witli 
vegetation.  In-fore  the  commencement  of  the  <Jlari,il 
perio<l.  ITie  affinity,  which,  thoutrli  feehlp.  1  am 
asHurod  l>y  I>r.  Hooker  is  re.il,  between  the  flora  of  the 
>*out!i-western  corner  of  Australia  and  of  the  (ape  of 
(Ji>o(l  Hofic,  is  a  far  more  remarkaliie  ca»e,  and  is  at 
j)re'<ent  ine.tplical)le  :  hut  thi«  affinity  is  confined  to 
the  plants,  and  will,  I  do  not  doubt,  be  Konie  dav  ex 
plained. 

11k^  law  which  cau-es  the  inhabitant*  of  an  archi- 
peliifi'o,  tli()ut:h  specifnally  distinct,  to  be  closely  allied 
to  tlio^e  of  the  nearest  continent,  we  ^ometinles  nee 
displayed  on  a  itmali  scale,  yet  in  a  most  iiitere.«<tin:i 
manner,  witliin  the  limits  of  the  same  archi[)el;u:o. 
Ilius  the  several  islands  of  the  (J;'.laj)a:ros  Ar»  hipelaifo 
are  tenanted,  a^i  I  have  elsewhere  shown,  in  a  quite 
marvellous  manner,  by  very  closely  related  species  ; 
so  that  the  inhabitants  of  each  separate  island,  tlioiicli 
lno^tly  di«itin(-t,  are  related  in  an  incomparably  rlos«'r 
de^Tee  to  each  other  than  to  the  inhabiUiiits  of  any 
other  i)art  of  the  world.  And  this  is  just  what  mij:ht 
ha\e  Iteen  exj»ected  on  my  view,  for  the  i  lands  are 
situated  so  near  each  otiier  that  they  would  almost 
certainly  receive  immigrants  from  the  same  oritrinal 
souri  »*,  or  from  each  other.  But  this  disj»imilarity 
l)etwt'i'n  the  endemic  inhabitant>i  of  the  island*  mav 
be  Used  an  an  arjfument  au'ainst  my  views  ;  for  it  may 
be  asked,  how  has  it  happened  in  the  several  island- 
situated  within  sij^lit  of  e-'u']»  otliT,  havin;;  the  same 
y.TiIofiiciii  nature,  tlie  sume  height,  diitiat*-.  etc.,  that 
many  of  the  immigrants  should  liave  been  ditferentK 
ino<l.:ied,  thoutrh  only  in  a  sm.ill  decree.  Thi*  lonjf 
.aiiiM'.ired  to  nie  li  irreit  difFlcuitv  :  but  it  -irises  in 
"iiief  part  from  the  di'e[>ly- seated  error  of  con-ider- 
inp  tlie   physical   condition."*  of  a  lounlrv  a.s  the  m     t 


360 


ON   THE   ORKJIN  OF  SPEC  IKS 


f 


II 


important  for  iN  ir.l.al.itants;  w}„.ro,-,s  if  ,a„„ot,  I  think 
.e  d.sputnl   that  the  nature  of  the  other  inh^h.^nt*! 
«    h  which  e,u-h  h,.H  to  compet..,  i.  at  ioant  a.,  imnort- 

M„ce.s.      No.v   ,f  ^.e   look   to   those   ,nha!.itant.s  of  the 

of  tZ'T  •,V'';,"''V'^'-"  "•'''■''  •''^•'  f'"""J  i"  other  inrt. 
em.     i  ^'''y;'^'  •>"  '>»e  .ide  for  the  moment  th. 

endemic  .pecTs,  wh.rh  cannot  he  here  t.iirlv  included, 
Hs  veare  con.Hleru.;.  how  they  have  come  to  he  modi- 
lu'.i  .  n.e  the.r  arrival),  we  find  a  n.nsi.ierahle  amount 

mi.;!  in";"".  '."  *'",  '"'"'"'  '■'^'•'*'"'^-  ''■'"«  -litference 
"Ufh     indee,!  have   been  expected  on   the   vie^  of  the 

Inland,    having,   heeri   stocked    by  .u-ca>ional   means   of 

^r.ins,,ort-a   seed,    for  instance,    of  one   plant   iiavi,,^ 

-nhro.n:ht  to  one  island,  and  that  of  another  plant 

'"  another  .>land.      Hen.e  when   n,   former  times  an 

nnm:,,-a,it  settled  „n  any  one  or  more  of  the  islan.ls  <.r 

when  1    Mihse.,uentlv  spread  from  one  i.sland  to  another, 

wo„ld    ,„„,nuhtedly   be   exposed   to  ditferent   condi- 

to  compete  with  different  sets  of  or^ariisms  :   a  plant 

or  m.  a„ce.  uouM   rind   the  hest-fitfed   ..round  Inore 
rfc.   ly  occupied  hv  distinct  plant,  in  one  islaiM  than 

nano  her   and  it  would   he  exposed  t<.  the  attacks  ot 
somewhat  different  enemies.      If  then  it  varied,  natura 
^elec  ion  x.ouM  prohahly  favour  dirierent  va.  .,tie«  i, 

he  dirierent  inlands.      Some  species,  however,   n?!^h 
^  .rca.l  and   yet  retain   the  same  character  throughout 
'he  .^roup,  just  as  we  see  on  continents  somo  specie^ 
^pwidin-  widely  i^tul  remaininjr  the  same. 

he  really  surprising  ta,t  in  this  case  of  the  (Jala- 
I'.i^'os  Archipela-o,  and  in  a  le:,ser  decree  in  «ome 
Hn.do.ous  instances,  is  that  the  new  snecies  formed  m 
•. n.i  separate  islands  have  not  (piickfy  sj.read  to  the 
-.Hier  islands.  I{.t  the  i.land-,  thotieh'  in  si.^ht  of 
each  other,  are  sepamted  hv  .leep  arms  of  the  sea  in 
n.o<t  case.s  wider  than  the  Hriti.h  Channel,  and  there 
•  H  no  re.Lson  to  suoDose  th.-it  th'"'  ><-•.-  -»  •..-  f—  -. 
F.ono.1  l.een  continuously  united."  Hie  curren'ts'o/the 
8ea  are   rapid  and   sweep  acres.-    the   archipeL-o,  and 


iiVAHiRAVUlCAL   DlSTIUMniON         :u]\ 


falpfj   ..r   wiii.l   are   i-xtriorflinarily   r.ir.' ;    no    th;it   the 
iBl.nml-  are  far  more  etfectually  separatod   fnmi   earh 
otli.T  tharj  lliey  appwir  tn  \>v  on'  a  map.      N'evertliele.ss 
air.xHl  many  «pories,  ()olli   tlxwe  found   :u  nthvr  parti* 
i»t   the   world  and   those   confinod   to   the  archi[.«'{aifo, 
in-  common  to  the  >*pveral  i«laiidi-,  nnd  we  may  inter 
irom  (.Tt.iin  fact.-  ih.it  flii-.-e  have  pro^Kihly  spnvi'd  from 
"Mvip  ..lie   i..l:ind   to  tlin  othor^.      Mut  we'oftcn  take,  I 
Miink,  an  err.m.'otis  view  of  the  probahility  of  .Josel'y- 
•lili.  li  spf-ci*-!*  invadinir  each  other's  territory,  wlifn  put 
into   frer    intercommunication.       f'ndouhtedlv    if  one 
-prcie.i  iias  any  advantatfj,  whatever  over  another,    it 
will  in  a  \.vy  brief  time  wholly  or  in  part  sijf.pl.uit'it  : 
lut  if  hoili  are  e<|uallv  well  fi'tt.'d  for  their  own  pl.ue- 
.n  nature,  hofl,  prohahly  will  hold  their  own  places  and 
kr»'|.  ^tparate  for  almost  any  lentrtH   of  time.      Meinc 
im;Ilar  with  the  fact  that   many  sneoies,  naturalised 
'tin.i'urh   man's  .Mrenry,   have  spread   with   astonishing 
r.     j.ty  over  new  countries,  we  are  apt  to  infer  that 
!i:  .-t  aperies  would  thus  spread;    hut  we  should   r»- 
rn» mta'r  that  the  forms  which  become   naturalised  in 
new  countries  are  not  eenerally  closely  allie<i   to  the 
a''>ri-in.il  inhahitants,   hut  are  very  distinct   species, 
'•■loi'L'-in^  in  a  lartje  propt.rtion  of  ca.ses,  as  shown  hy 
Mph    do   (andolle,   to  distinct  ifenera.      In  the  Cab 
•  vi.'os  .Ar.hipelatfo,  many  even  of  the  birds,  thoutrh  m. 
'.11   ad.apted    for    flying    from    island    to    island     arr 
iistmct  ou  each  ;    thus  there  are  three  closelv-all  e.l 
-pe<ies  of  mockin^-thrush,   each  conHned  to  'its  own 
"-land.       Now  let  us  suppose   the   mo.-kinp- thrush  of 
t  hatham  Island  to  be  blown  to  (  harles  Island,  which 
n:L<  It.,  own  mockin^'-thrush  :    why  should  it  Buccecl 
.n  est;,Mi>hin^  itself  there .-     We  may  safely  infer  that 
(  har.e.s  Island  i.s  well  stocked  with  its  own  specie.-?,  for 
■iriniiallv  more  e:rirs  are  laid  there  than  can  fxKssibly  J^ 
^' Mred  ;    and  we  may  infer  that  the   mockitijf- thrush 
('«'-'iliar  to  Charles  Island  i.s  at  lca.st  a.s  well  fitted   for 
'     hou.r,  i,  i^  the  sp.-cies  peculiar  to  (  haUiam    Island. 
■r  (  .    Kyell  and   .Mr.   Woila.ston   have  communicated 
'o    ifif    «    ren.arkaMe    fact    '.earinsr   on    this    aubjcct  : 


M2 


ON   THE  ORIGIN   OF  BF'FXIKS 


► 


namely,  that  Madeira  and  the  adjoinini^  islet  of  Port/t 
Santo  poHHeBfl  many  diMtinct  but  ropr>»«entative  latid- 
nhrils.  Ronie  of  which  live  in  crevicPH  of  «tniie  ;  and 
;ilth<nij/)i  larifp  quantitio*  of  Rtone  are  annually  traiiH- 
portisl  trorn  I'orto  Santo  to  Madeira,  yet  thiw  latter 
island  lias  not  Iwromo  coloniswl  l»y  the  I'orto  Santo 
8|»ei"ies  :  iH'vi'rthelpss  hoth  ifiland-  have  Inen  rolo!ux«'d 
by  8oni»'  Kur()p<Mn  land-HhelU,  wliiih  no  <loul)t  hail 
some  ;nlvaiit«fre  over  the  indi«{eiious  --peries.  Krom 
tiipie  coiisideratioriB  I  think  we  noid  not  ereatlv 
marvel  at  the  endemic  and  repres«'iitativo  Kpecit>, 
wliich  iiihaliit  tlie  neveral  i-ilainis  of  the  (i Lipruro-^ 
Archipelatfo,  not  liavinjf  iinivcrwiliy  Hjiroad  from 
i.-lan<l  !i>  i»iland.  In  many  other  iii'-tancen,  an*  in  tlie 
sevrral  districtH  of  the  name  continent,  pre-occiipatixn 
hi-i  probably  played  an  important  i»art  in  chockinjf  the 
comniinglinjf  of  sp»'iies  under  the  same  conditions  of 
life.  Hiiis,  the  Kouth-east  and  Houth-west  corner*  of 
An>;tr;ilia  have  nearly  the  same  phywical  conditions, 
and  are  united  by  continuous  land,  y»^t  they  rire  in- 
habited by  a  vast  numlier  of  distinct  mammals,  birds, 
and  plaiit>. 

I'.ie  principle  nhich  determines  the  jreneral  rb  ir- 
acter  of  the  fauna  and  flora  of  oceanic  islands,  namely, 
that  the  inhabitants,  when  not  identically  the  same, 
yet  are  plainly  related  to  the  inhabitantB  of  that  rt-irion 
whence  colonist*  could  nio«t  readily  have  been  «lerive<i, 
-  the  colonists  having  been  subseijuently  modified  and 
better  fitted  to  their  new  homes,-- is  of  the  wide«-t 
applicatirin  throughout  nature.  N\'e  see  this  on  every 
mountiin,  in  every  lake  and  marsh.  For  Alpine 
species,  excepting?  in  so  far  as  the  same  forms,  chiefly 
of  plants,  have  spread  widely  throuirhout  the  world 
durint;  the  recent  (ilacial  e|M)ch,  are  related  to  thn>ie  of 
the  Kurroundiuff  lowlands  ;— thus  we  have  in  South 
America,  Alpine  liumminaf-birds,  .\l[iine  rodents, 
Alj)ine  plants,  etc.,  all  of  strictly  American  forms, 
and  it  1;^  >>bvio"=  *}i"*  s  rr*o!!?;t;;i!!,  a-  it  be^'-r"*^  t;|ow!r 
uphe.ived,  would  naturally  be  colonised  from  the 
•uiroundin:{  lowlands.      So  it  is  with  the  inhabitant.-  of 


Mm^mm^wmm 


^m^mdmim'^ 


oeo(;rai»hical  distrihc  tion 


363 


lake*  and  marthoa,  excepting  in  ao  hr  tu*  ertmt  facility 
of  traiis{K)rt  haa  trivftn  the  name  jceneral  fornn  to  th* 
v»hole  world.  We  B«»e  this  aamo  priucij.!*'  in  the  Mind 
;iriimaN  inhahjtinff  thp  raves  of  America  and  of  KurojH?. 
Other  analosrouH  fact*  could  be  jf'ven.  And  it  will,  I 
Iteiieve,  \>e  universally  found  to  !.<•  true,  that  wherever 
in  two  reifions,  let  them  l)e  ever  «o  distant,  many 
rloiely-aliied  or  representative  iipeciea  f»ccur.  there  w.fl 
likewise  be  found  some  identical  siM'cien,  Hhowiin;,  in 
accordance  with  the  forejfoin^  riew,  tliat  at  some 
former  j>erio<l  there  has  ».een  intercommunication  or 
mi^rratir.n  hetween  the  two  re^rions.  And  wl.ereMT 
many  closely-allied  species  occur,  there  will  l»e  found 
many  forms  which  some  naturalist*  rank  as  distinct 
-I'ecies,  and  some  a«  varieties  ;  these  doul>tful  fort  i* 
Hlinwinp  us  the  steps  in  the  process  of  modification. 


B  pi 

tin 


Ihi-<  relation  bietween  the  power  and  extent  of 
migration  of  a  species,  either  at  the  present  time  or  at 
some  former  {)eriod  under  different  physical  conditions, 
and  iho  exi.stence  at  remote  point*  of  the  worici  of 
"tlier  species  allied  to  it,  is  showii  in  another  and  more 
reneraJ  way  Mr.  (lould  remarked  to  me  long  .itf... 
*hat  iu  those  irenera  of  birds  which  r^uga  over  the 
world,  many  of  the  species  have  very  wide  ranges.  I 
can  hardly  doubt  that  this  rule  is  jrenerally  true, 
thoMtrh  it  would  be  difficult  to  prove  it  Amon^nit 
mr»mmal«,  we  see  it  strikinjrly  displayed  in  Bats,  and 
it!  a  les.ser  depree  in  the  Felid*  and  (anid*.  We  .see 
it,  if  we  compare  the  distribution  of  butterflies  and 
fK-etles.  So  it  is  with  most  fresh-water  productions,  in 
which  NO  many  genera  ranj^e  over  the  world,  and  many 
Individ uiil  specie*  have  enormous  ran^s.  It  is  not 
mea;it  that  in  world -ran^injf  jfeuera  all  tlie  species 
have  a  wide  ranjre,  or  even  that  they  have  on  an 
a\-4-r,i,jf  a  wide  raiiije  ;  but  only  that  some  of  the  spe<  iw 
raiitfe  very  widely  ;  for  the  facility  with  which  widel- 
ranirin;,'  species  vary  and  pive  ri.-^e  to  new  forms  ni!l 
iart;eiv  delejuiine  iheir  average  rantre.  For  iustan  e, 
two  varieties  of  the  same  upecies  inhabit  America  ar-i 
Kuroijc,  and  tiie  species  thus  has  an  immen'*  ran^e  ; 


^mm^^l^!^!Wi 


r^ 


^^'■fi^mM 


iiU:'^! 


sjarrr^.r 


MICROCOPY    RESOLUTION    TEST    CHART 

ANol  and  ISO  TEST  CHART  No    2 


1.0 


I.I 


1.25 


1^    ||2.8 

2.5 

11 

2.2 

i_ 

I-  

1   2.0 

^ 

1.8 

1.4 

1.6 



^     APPLIED  iryHGE     Inc 


1A609 
-.-^         ,^.,        Phon« 
■  6)   288  -  5989  -  Fq. 


^,;^^^*k 


Ifti 


ll! 


;3«;4  ON   THE   ORIGIN  OF   SPEfIF> 

but,  if  the  variation  had  been  a  little  Kreator,  the  two 
varieties  would  have  \teen  ranked  »s  distinrt  sppcjes, 
aiid  the  .' mrnoii  ranee  would  have  l)e»Mi  u'rcatlv 
reduced,  .-^till  les-*  i>  it  meant,  that  a  sr>e«'ips'"-.vhioli 
fipparently  h,i«  the  .apncity  of  crossin?  harrier*  ind 
rantrinif  widely,  a«  in  tlie  case  of  certain  powertnlly- 
wiii^M'd  birds,  will  necessarily  range  widely  ;  f.,r  we 
should  never  fort'et  that  to  rariire  widely  implies  not 
only  thf  puvM'r  of  crossing  harriers,  hut  the  m^re  im- 
portint  power  of  hein^  victorious  in  -iistant  lands  in 
the  strutrjfle  for  life  with  foreiifn  .•\>sociates.  Hut 
on  tl.M  view  of  all  the  species  of  a  ^enus  havinsf  de- 
scended from  a  sinijle  parent,  thou^jh  now  distributed 
fo  the  most  remote  points  of  the  world,  we  ou!?ht  to 
nnd,  9nd  I  believe  as  a  general  rule  we  do  find,  that 
some  at  least  of  the  species  range  very  widely  ;  for  it 
H  necessary  that  the  unmodified  parent  should  ranj^e 
widely,  underiToinpr  modification  durinj?  its  difTusioii, 
and  should  place  itself  under  diverse  conditions  favour- 
able for  the  conversion  of  its  offspring,  firstly  into  new 
^.iriefie8  and  ultimately  into  new  species 

In  considerinji:  the  wide  distribution  ot  certain 
c«Mipra,  we  should  hear  in  mind  that  some  are  ex- 
tremely ancient,  and  must  have  branched  off  from  a 
' ommon  parent  at  a  remote  epoch  ;  so  that  hi  such 
ase?  there  will  have  been  ample  time  for  great  cli- 
mata!  and  geographical  clianges  and  for  accidents  of 
tranfii-ort ;  and  consequentlv  for  the  migration  of  some 
ot  the  species  into  all  ([uarters  of  the  world,  where 
they  may  have  Income  slightly  modified  in  relation  to 
th»^ir  new  conditions.  There  is,  also,  some  reason  to 
behove  from  geological  evidence  that  organisms  low  in 
the  scale  within  each  trreat  class,  generally  chatiire  at  a 
s  ower  rate  than  the  higher  forms  ;  and  consequently 
t!ie  lower  forms  will  have  had  a  better  chance  of  ran^-inif 
■*uloly  and  of  still  retaining  the  same  specific  character 
I  his  lact,  together  with  the  seeds  and  eggs  of  many  low 

»raioj>ortati.)ri,  prof  ably  accounts  for  a  law  which  has 
h'ng  been  oh<erve<l,  and  which  h.is  lat.-'y  \»^a  »dmirablv 


GEOGRAPHICAL   DISTRIBUTION         363 

d.*t.u6.*ed  by  Alph.  dp  (andolle  in  re^rd  to  planU, 
namely,  that  the  Iow»t  any  »rroup  of  orjfanismn  in  th.- 
more  widely  it  ia  apt  to  ran^o. 

I  he    relations    junt   di^-ussed,  -    namely,     1o-a     au.i 
sowlv-chau^nir  ortanisms  rariKiuif  more  widely  than 
the  h,^h,^«ome  of  theHjH>ciesofwidely-ranifinK  jrenen 
themselves    raiiKnuK    widely,  — such    facta,    as   alniii.. 
lanistnue,  and  marsh  productions  beinjf  r.'lated  (with 
t)»e  exceptions  Wfore  specified)  to  those  ou   the  sur- 
rotindiiiir  low  lands  aud  dry  lauds,  thouph  tlie«e  st^itiofis 
are  so  dirfcrent,- the  very  close  relation  of  the  distinct 
bi^'cies  which  uihabit  the  islets  of  the  same  arch ipelairo 
and  especially  the  striking?  relation  of  the  inhabitiints 
ot  each   whole  archiiielairo  or   islaiid   to  those  of  the 
iiMrest  mainland,  -  are,  1  think,  utterly   inexplicable 
on  t!i«  ordinary  view  of  the   independent  creation  of 
each  gpeciea,  but  are  explicable  on  the  view  of  colon- 
isation from  the  nearest  or  readiest  source,  together 
«i;h  the  subsequent  modification  and  better  adapUUuii 
o«  tiio  colonists  to  their  new  homes. 

Sutnmnry   of  Uist    and  prtsrnt   Vh<ij,ter». —In    these 
ciMpters  I  have  endeavoured  to  show,  that  if  we  make 
'iue  allowance  fi.r  our  i^orauce  of  the  full  e!Tect«  ut 
all  the  chantres  of  climate  and  of  the  level  of  the  land 
which  have  certainly  occurred  within  the  recent  period' 
and  of  other  similar  chau^CH  wliich  may  have  occurred' 
within  the  same  period  ;   if   we   rememWr   how    pro- 
fouiuhy  ijfnorant  we    are  with    resjiect    to    the  manv 
and  curious  means  of  occasional  transport,— a  subjeci 
whuh  has  liardly  ever  been  pro|>erlv  experimentised  on  ; 
It  we  l^ear  in  mind  how  oflen  a  species  may  have  ranged 
continuously  over  a  wide  area,  and  then  have   Inn-ome 
extinct  m  the  intermediate  tracU,    1   think    *fe  difH 
culties  in  lielieviuff  tliat  all  the  individuals  of  the  name 
species,   whenner  IcK-ated,   liave   descended    from    tlie 
name  parents,  are  not  insuperable.      And  we  are  led  to 
t.-iis  concliiiiou,  wh'cii  ha.s   been  arrived  at   bv  many 
naturalists  under  the  denipiation  of  single  i-eiitre*  of 
creation,  by  uome  ffeueral  coiwideraLious,  more  eupeciall  v 


.  --r-4i^?,ui!. 


380  ON  THE   ORIGIN   OF  SPECIES 

from  the  importance  of  barrierH  and  from  the  aualo«nc«l 
.iMtnbution  of  8ub-^,.nera,  genera,  and  fam ,!...«. 

V\  ith    resoect  to   the  distinct  species   of  the   name 

-enuH   which  on  my  theory  must  have  spread  from  one 

pirent-Kource;  if  we  make  the  same  allonauces  as  l^fore 

c.r  our  lirnorance   and  remember  that  some  forms  of 

i»e  .  nan^e  most  slowly,  enormous  periods  of  time  iH-ioir 

hu^rHnted  for  the.r  migration,  f  do  not  think  that 

the  difficulties  are  insuperable ;  though  they  often  are 

in  this  case,  and  in  that  of  the  individuals  of  the  same 

species,  extreme) V  jfreat. 

As  eicemplifyin'^  the  etfects  of  climatal  rh-w.^e^  ou 
distribution,  i  have  attempted  to  show  how  important 
hiis  been  the  influence  of  the  modern  (ilacial  period, 
^  iirh  I  am  fully  convinced  simultaneously atlV.ted  the 
whole  world,  or  at  least  ^reat  meridional  beit^  As 
showing^ how  diversified  are  the  means  of  occasional 
transport  I  have  discusse«l  at  some  little  length  the 
means  of  d.sj,er8al  of  fresh-water  productions. 

if  the  dijhculties  be  not   insuperable   in   admitting 
that  in  the  lonjf  course  of  time  the  individuals  of  tliV. 
s.'ime  sj^eciea,  and  likewise  of  allied  spt^cies,  have  pn^; 
.eeded  from   some  one  source;  then  1  think  all   the 
errand    eading  fa.:ts    of  ^ei,»traphical  distribution  are 
explicable  ou  the  theory  of  mi^rraUon  Ofenerally  of  the 
m<.re  dominant  forms  of  life),  together  with  subseuueut 
modihcation  and  the  multiplication  of  new  forms      WV 
can  thus  understand  the  hitfh  importance  of  barrier^ 
whether  of  land  or  water,  which  separate  our  several" 
zoo  ojfical    and    botanical    provinces.       \V«    can     thus 
understand  the  Imalisation  of  sub-fTonera,  genera,  and 
families  ;  and  how  it  is  that  under  different  latitudes 
for  insuiue  in  South  America,  U;e  inh-Mtants  of  the 
plains  and  mountains,  of  the  forests,  marshes,  and  d.»serts 
are  in  so  mysterious  amanner  linked  together  bv.uffi'nitv' 
and   are  likewise  linked  tx>  the  extinct   Umiu^s    which 
ormerly  inhabited  the  same  .  ontinent.   Hearing'  in  .lind 
that  the  mutual  relation  of  onrunism  to  or-anism  is  of 
1!=---  :::i;:ic-..L  i;i:p<;rUriCC,  we  lain  see  why  two  areas  havinir 
nearly  the  same  physical  conditions  should   oflen   he 


(iEOGRAPHICAL   DISTRIBLTION         367 

nut  o  horn  to  enter,  either  in  neater  <,r  le^.V^rC 
.•M.-..r.li„fir  ornot,  a.s  those  whi.h  enteral   hi.  .  .  ' 

-;  ■■  -ly  related  ,„  eaC,  other,  .ndllw  «  W  V     "tei 

.'ii;. :,;;:"::',,::.,;'";: 'f  '■■•, — * <■-".":!; 

rived.      «->?..r..!!'.^..  ""f     ^   "■"'    I'"'''"'''''    *•■ 
tJ.e    p,e«oc,    „f  Idemicl    .pece,,    J''^^:!    u, 


368 


ON   THE  ORIGIN  OF  ^PECIKS 


m 


do^tful    .pedes.  a,H    of  distinct    l.ut    repraser.Ut. 

A.  tl...  l;.t..  i:,lvvard  Forh.s  ..ft.M.  in.i.tocj,  there  i, 

r.    L  '         ■       ''    ■'"■'  '^'•'V'-'""-'  '»'«  "un-cssion  of  lorn 
pa.t    nu.s  |.e,n..  n.arly  the  .s.unc  uith  tho.e  «.u    " 
m^  at  the  pre>ent    tune    the    differences   in  \uZll 
ana..      W  o  ^ee  this  ui  inanv  fact^.      rj,,,  endu,  .n.-e 
-h  npenes  and  ^n.up  ol^.eeies  is  eontinuou^  ;      ^i 
tor  the  ex.e,.  .ous  to  tiie  rule  are  ho  few,  that  tl  ev  Z 
fairly  }>e  att.;h.,ted  to  our  not  h.-.vinir  « s  v "t  H       ^ 
m  an  in,e..u..l.ate  deposit  the  f^!!: :^.^  ^^^^ 
absent,  but  wh.ch  o.-eur  ahove  and  helow  :  m,   „     .a'" 

♦^.roups  01  spe<,e..  belonjfintr  either  to  a  cer  -^    '  i 

•>f  time,  or  to  a  certain  area    .re  oC  oh  .r-L;     -'"T'l"' 

iii.l  lliat  Miuri.  (,r«aiiism»  differ  lllll,.   »l,il ' , 

tr-atl  .     I,.  I„,i|,  t„„p  ,„j  space  the  l.,wcr  mem  Wr7^( 
a.),  ,1.1,,.  ,.,.„,ra|lv  ,-l.a„;;e  L»  than  tli,-  iS  „     t ,?, 

-tw„r.i;or";Lr!:s^:^'r'''H"''"I''"^ 

quart..r«.  ,„  l,.„"l'-'i/j'.';:,,  ;"_'"-'  "".-"""l  "'to  di,la„t 


^i^'.V>« 


X'sfe'i^>%7 


= if  V  ;>&;=: 


S3i£4rjS?'  .it;?)^,^^!^ 


;^->^i:v<* 


;:|.^<M5^*i?<?i>;v^ 


or 


r.K(  HiHAPUH  AL  Dis nun[  rio\ 


atiori  ;  «ri(i  tlie  more  iiparlv  anv  »«..  f 

-  f-!"'"l,  the  nearer  tl,;     'in'^,  ^^   ,^'"'7  «7  -''''^^'^ 

"tfH>r  iri  time  and  .j«ce     in  hoth  .    i«   f  T"^  ^c    '"'''^ 


2b 


^S'S^'^F'^T^-JES^/i 


'   MAI'TKFl    Mil 


I 


-'•  rr.w    Afn.viTiKs  ,n-  ohnam.     hf.isoh:    moih-holoo 

KMIlUVofooY  :     Kl LIMKNTAltV    OI».;avs 

.).-.■•  nt   with  n,..,|inr«tlr,n-ClaMm,M|.,',  o/   varlM^.        o7, 

-A-;,,  ti.  «.  een.-n,l.  ,o„,pi„  „„,  rH.n.ifinK-  Kxti  „   i  .n  il^;!^ 
an.l  .!.  •l„..-i:r..,:,«     M,,r,.h,.i..,.v.  i^.,«..en  mi..n^^ri    f  O.o  ,a 


in'.M  th..  fir.t  .l.iWM  of  life,  all  orjranic  hoinen  nro  roun 

•n  r.'MvnM,.  oa.h  other  in  <l,s<-.„.ii,u;  dtvre,-.,  .o  thf 

t  H.V    ran    1...  rla^vf,!    iri   ffroupn   under  irrouiw        'n,, 

;-..-.^MfMati..n  h  evidently  not  arhitrarv  like  the  ^rour 

■  n-   of   the  star^   in   constellations.     ■H.e  existem-i.  t 

trn.iij.^  would  have  heon  of  simple  sie-nifieati.ui    if  on 

-roui)  had   heen  evclusivelv  fitted  fn  inhahit  the  land 

and  anot.ier  tlie  watrr  ;  one  to   feed  on   flesh,  anothe 

-n  ve-..tal.le  matter,  and  so  on  ;  hut  the  case  is  wideh 

•iiff.'rent   in   nature  :   for  it   is  notorious  how  commoni; 

'"••'Mhors  of  even    the  same  suh-^rroup    have   differen 

hah.t-s.      In  our  second  and  fourth  chapters,  o„  \-ariatior 

and  on  Natural  .^election,  I  have  attempted  to  show  thai 

1   IS  the  widely  ran^ri„..  ^.e  mu-h  diffused  and  conur.on, 

that  IS   the  dominant  species  helon-intr  to  the    larirei 

crr.era.  whi.l,  vary  mo.f.       "n.e  varieties,   or  incipient 

^fvPCiCH,  thus  produced  ultimately  iK^come  converted    a« 

I  ••elieve,  ,„to  nev.  and  distinct  sptvics  ;  ami  the^.'on 

'..f  priu.  ipie  oi  mueriunce.  tend  to  produce  other  new 

;;7m 


L;r.>^, 


^^il^0r^Mm^'rmMmf?. 


(I^ASMHCAMON 


n7i 

.r.  MOW  I„5P,  i„,  which  JerAXLl    .''"''''•'  •''"•'^ 

"f  natur*..   there  is  s  cln.t^ra  terTI  *:  <'<'o,u.mv 

i.oki„eatt^eI.r..t   1    ^r^^r^^^^^^^  ""Pr-^-'    by 

•n  a,u   .mall  are;,   cor,  ^  1  /h       f"'"'"'' '*'  'i^'* -'"^h. 

'    atten.j.tci  also  to  -lu^/thTt    t-    '    ' 
•I'"]  ,l;veririnir  in  .harnrfer  f  '"Toasu,^  ,„  ,„„„f.^r 

'<>"  I-.  duer^ent    ti-.  I  .     "''^^'•■'"!"'''^  '"xternnnate 

-"-  '  -'i-i  the'VJ;;;;';:!-;;;;  • -|  f'T""'"'^ 

''"'-tratinjftheartion    as  formp^lJ         .       ^^\^  <f'-';rrarn 
"«"  pr..eenitor  hecome  hroU,  !    P'-ocee.lirijf  from 

'"•".•.Line  in';r„^i*"'''i "  Tir";;"--  '""•  '"'■"'""' 

'   from   a  i-(unmori    nar...,f  „»  ^i  .  ...-.    '•  *""cn 


'^■"-iiKin  riarifj.  \»h  rh 

•;mm..„   parer.t  at  the  riftf,  .ta..e  o 


;'— t.  Th,.,  fi.r;;  ';^T  .  ■; ''"  '^'^!'  •^^^••'« "' 

'•-.  i"  common  :  aruJ  they  fo  n  a  ' ''•,""r"^-'   '*'""^''' 

^''^•;t  liari.l.   nhi.h  .livfr^-H  "^^  '"*'"   ^"    ^^•■" 

,,,       1      .  K»  "era,    liexeriilod   from   (  \.\     c 

^T-u-r  liNtirirt  from  the  .r^M<.r    J        "^'^ni  f\),    furnian 

rtii  un.ie<i  ijito  one  cla.«s.       'T\\\i% 


% 


ON 


'HK   OHKWN   (;K   .vf'KLJF> 


'*'-^'r;w..i  u,i  u.  natural  l.i.tor;    ni  ti...  .„|,or.lin. 

-e,..rat,n.Ml.o.o«hi..h  an-  mo.t  unlike  ;  o   a  .':«" 

tl.n-|.  cornm.m  to  the  do^r-^enu..  and  Ui^/  I  v  aH   " 
-.d.  sente„o..  a  full  des.r.,.tio„  is  ^rve^  o  "  o^r     k 

luoputal.le       liut  many  naturalists  think   tliit   «n^ 
nn.^   more   ,s    ^e..nt   by   the   Natural   s's^^  •  "^ 
'"    "^t'/luf   It   reveals   the  plan   of  the  ('Vea^r  • 
«"1"-   .t    ...  <,K..nfied  H-hether  order     ,   .^inTor   '  J 
or  Hhat  else  is  meant  hv  th-   plan  of  t .«  ?       I^ 
reern.    to    n,e    that    nothir,,    rLj  ^de  l"'to"o 
knowledge.      .Surh   exnre.-<sions  an   that   hT 
--..us.  a,.d  which  /e  otlen  mtet'';!  h'^ir.  mc.';: 

'o;;u'  ri::;' ufatT'  ^''^^ ''"  ^''^^•"•^«"'  ^^^  - "-" "  i 


in   iiii 


icient  timen   thnuk'ht)  thaf  tf 


.LTu.turn^lMch  (lefrn.inecl   the  hal.iu  of"  I 
.♦•fuTal  pj.ice  of  tacfi  l.p 


i«»tM'  jKirtjj  of   the 


iiitr  in   the  .-com.riiv  of  mit 


•  nu  ,1   W   of  very   hi^h    i..,,.,.rUm-e    in    .1 


i»»*.  and   fh»' 


lire. 


Nnffjititr  cAii  h(« 


ninre  false.     \( 


Mficaf 


lotl. 


•flrnilanty  of  a  mouw  to  »  nhrew,  „f  «  j 


f>riere:rr,rris  the  externa; 


"f .»  ^hale  to  a  tish 


hi 

lit 


tu  of 


.inn 


ariv  im 


f-*^.  tfioijt.'h  Ko  intimate! 


porta 


ii-'Tjif  to  a  vOiale 


lue. 


'II 


iff*'  rt'sefii 


'•'  <>t  the   heiriL'.  arf   ranked 
kiI"_'1imJ  fJiaraftiT-*" ;   hut  to  t\ 


y  connert,.,!   *ith  the  m  hoi. 


Alfc'lH.  '] 


^   merely  '  adapt i^w 


ilf'rat 


or 


•  "   •   ■■"!.  lo  iiiB  rolls 

re..,Mhbnr«  ue  ^h;.ll   have  to  reeur.      ft  may  even    U- 
if.v.M  as  a  .^eneral    rule,  that  the  less  a  iv^rt  oV  uT 
on.M-„^-rtionuro,u-erned  with  special   hahft,    fh« 
in.porunt  it  Wome«  for  da^sitirE.       A .  !?  "'"'* 

<  »wfn   in  noeakino-  of  n,^    '^''"ration.     As  an  lUMtanee: 
tn,  innpeakin^of  theduifon^',  Mavn,  '  Hie  irennr-itiv.. 

*;?     5;rr'*'i"'^''^''«"""^'^trueatKniUeV    UV 

'l.ere^  th.  orpu,.  „f  ,epr<Klucti„„    »i,h  their  Lr^'.,' 
I."  feed.  ;.r.  of  paramount  importaiir,  ■  "^ 

>U.  mu.t  not,  therefore,  in  cf.mifvi„„  i,u„  i,,  ,„  „ 

=^e.v  :a;^rr?r  "th'^ts-rs^vj^rirrS-r 

•;  '  outer  vrorld.      Perhan^  from  Iv  ;1       *^         relation  to 
.1         I  cruaps  rrom  tnia  rauae  it  hxM  oarti, 

arisen,  that  almo.t  aU  natunUiHt*  lav  the^r«,u^t'sTr    ' 

-"■7  throughout  Ur^e'^^Tou'^  Z  ^J:"'^^  'Z 
^ijfaii   uoen  not  UfUrniine   i»v   rja^f. 


It 


374 


"N    niK  (.Kj(;i\  OK  >j.|.^  j^;^s 


"•a...,,  to  '  i;'"; ; '« -''"« '-^-'. -  -  i.-o.. 

valu..,  ,t.   rji      ':.    :      "7'''>;  "'♦•   -""••   pl.VHolo,^ 
''••''''r;U,    .,,7    ';'r :••'''**  '■"  ^"'-'y  •i.ffem.L 
-tru.k  .:,  ■     h  ,   fa.t         1  ^;r^-»^,^-M'  "Ul.out  U. 
'•"l-'-i    .n    t.      nt      •     "VS''"   '"*'"   ''^">»'k.i. 
-''i    -'f....    U.    ^.    t'Xe    H    ;"'V    *"^7>    -"*''"^- 

•♦.■iVH.  t»ie  tr.-iji.ra  ,,r  tl.»  V  'i'lutlier  work 

•'•nM.rth.se  cw;"t";''r.''';''l''^  -ti..tion.      A, 

"'H'  JTobaMv  Hill  Ha     tV«t  n         ' '•'^^""■*^'""  ;  yet  II 

i'"l'<TUnt'..r^„i  u     hm  tL       '^^"'^•^l'""  o^he  wru, 

or,^ai..  are  o/hi^  /  ,.1?  ,  .^T    '"""'''•"^^'V  "^  *tro,.lu.c 
vet.  undoubU.dk    or!  i''hTr'*^  "^^."^  in.portaure 

the  rudimentlAC      •   7L    -^^  ""*'  '^'^  ^-P"te  that 
nants,  and   certain    r         ^^V^''?-'*""  "^^'O""*?  nimi- 

tHWM  KuminanUandpf       ^^   ti.e  .Iums  affiruiv  be. 
^tr..nd V  .n.si.st:ro;    he  f  .  IXAT "      "r'*^  ^'^"^•"  ^ 


'>^l 


/ii-^i 


vT^:-y:^^' 


rLASSIHCATlON 


;»7A 


.iern,.d    trum   iwrts  whirl,    nuint   1«  cunHi.IortHi   ..fx.-r.. 
tndui^  l.l.VMHln^M.al  nn,n,rr..iut.,  but  «in.l,  urn  utnv.T- 
•allv   ^i.lii.ift.vl   a.    In^hly   »*Tvu,.a!.i«   in    the  .leMutiu:; 
'■J«h..l,.  t::,.ii|...      iM.ri/i.Ui.c,.,  MhrthtTor  notlluT.     - 
-.1  .-I"-"    |'.i>-M^o   trw.n    the   iio.tnls    to  tl,o    r.M.iith.  i,.,- 
o.il)  il.Hra.t.T,i.,vi,rdin^to(*w,.ii,HhichaU4,liit,.lv.i„ 
tMipi.>l.eH  ..,!,..>  a.id  r.',.l.j,..-tl.e  iuJicrt.on  o!  tiioa..  ■!. 
"J  the   i.iH,  Ml   Marsu|.,.»l.s-  the  ti.ann.r  in  wiu.h   t"h,. 
*in»rH   of    ,M.tH-t^  are    h.lded-    mere   roh.ur   .u    .  erUu. 
\l^>r     ,,,,.,-e    |.ul.esc,.i.,e    on     partiH    ot    the    fh.^^t-r    ,u 
»rraH...,      .ho  UHt.no  of   the  der.ual   .ouTiuc.  .1.   ha.r  or 
.^Iher.,  nuhe     ertohruu.     If  the  ( )rnahorhv  ruhu^  had 
l*Hn  .u.c-rc-d  HUh  feathers  iuMead  of  hair,  tin.,  euernal 
aiid    trifling   rharartvr   Houhl,  I    think,  have    i..-,  n   c  un 
ml  ,\"    :'^^"^^''^*^   ^   i.i.|.ortHnt   an   a.d    ii.    deter- 

m  nu,^    he  de.^ree  o,  affinity  of  th..  .tran^^e  crcuur.   to 

,n     r  "f  "T     ''''  *"  *"«M'^^'^^t'  i"  '.tructure  in  a:u  uu. 
iiiternal  and  inipurUnt  orj^an. 

r).«  ini,.orUn.-e,  tor  cU.,ticatio«,  of  trifiuiir  <  hara.  - 

•eu'ral   other  .hararten.  of  n.ore  or   le«.s   ,nw.ortan... 
he  Nalue  Uid^'ed  otan  a^^e^mto  of  .hara.  ter»  ...  verv 

r  .    .rkod,  a  .pe,:,eH  may  dei«.rt  from  iU  allien  ui  Keveral 

-ru  terw,  both  of  hi^h    nLy.iol.,^ic*l   imjH.rta.ae  a,.l 

"  aJ  ,.o.t  nniver^   urovalenee,  aiid  vet  have  u.  in  no 

iouhtwhire  itHhoufd   Ih5  rauked.      Uenve   ah,o        ha 
'-;;  .uund    tlut  a  oL^ifi.atiou   founded  ou  an  '  .'t 

ijracter.  boHever  .mp..rUut  tlmt  may  »hj,  ba-  alwav. 

■onl;  !"'lT  •''*''  ""^  '^*'  or^uuuiaon  i.  universal), 
'  .  ^tanl.  He  .mpoi  ^nceof  au  a^»?re^^t«of .  hara.  t*,r«'. 
e  .  i  when  none  are  unport^t,  aTooe  expU.r..,  1  ib.nk 
t^ KU  sayui^  of  knua-us.  that  the  charactl-n.  do  not  t,ue 
ti>e  *renu.,  but  the  ^enu-  ^vo.  the  eharac-U-r.  ;  for  thi- 
•^vn^f  «eem.  founded  on  an  ap,,re«iaUon  of  manv 
inun^  po.nt.  of  resemblance,  too  .li*rht  U>  he  dehned 

i-rfe..t  a.,d  de^ra;ie^fl;^;;  ^  ■:i;^*ut;:;i' w: 

Jus..eu    ha-    reuurked,    'the   t^re^ittr    numhc-r  of  tL. 


II 


*1 


•I .  I 


■'  ^  *  ^''\'  *,  •*^'*'  '''-'I'P'.'r,  and  thus  la,,-!,  at  oi 
■^1— .<H-atH.n.  Itut  «1h.„  .,.pi..arpa  pro.i.re.l  in  J-r 'nc 
'lurn,,.  H.v.;ral  w.-.rs  only  ch.,.ra'i..l   (iovrer        .'pa 

U.J,.„dnan.;P.       /  In-  ra^o  seen..  t„  ,ru.  wt-ll  t-  i.lustr . 

I'ra.lically  wlu-ii   naturalists  are   at   work     tl,...-  .1 
-t   tn.u Me  thern>elve.  about  the  phvsXioa   Val   I 
o        o  .•  .ara..ter.  .hich   they  u^e  in  .jVriniri  a    -rui 
'.r    n   alloratn.u'  a,>y  partieular  speeies.      If  tu^;     "n 
■^  -^Kiracter  n..arly   n,ufonn,  an./eun.mon   to  a  J^ 
.'in.'-roflorms    and   noteomuMm  to  others,  thevust 
•t  as   one  of  h;.^h    value;    if  c.uu.non   to  .o,       lesse 
""".her,    they    use   it   as   of  suhordinato   value        nZ 

)  t  e  the  true  one  :  and    l,v  none  more  clearlv  than   hv 
th:a  excelient    hot^-ust,  Au;,.   St    Ihlairr      f     e^^ 

-ararterH  are  alwa.^n  found  .-orrelated  with  oU^A 
t!'""ch  no  apparent  bond  of  connertion  ,a  he  S 
...veu-d  between  then,,  espe.ial  value  is  .et  u  them 
As  u  most  .^rouj.s  of  animals,  in.portant  o^.^u,s,  such  as 
'j'--.'  tor  propelhn;:  the  blood,  or  for  aeratin-  it  or  t!  ot 
"T  i.ropa,^■itu.,^  the  ra.e.  are  found  nearly  ni  Vm  C 
■^re  n.ns.dered  a.  h,,hlv  serviceable  J  U^^^^. 
u>ome  ..roups  or  a.umal.  all  the.e.  the  mo.tim-* 
MO'Unt  v.ta  ortra.is,  are  four.d  to  olfer  ehararu-.  o/ 
■Miite  .suf.orduuife  value. 

^boulVb.'';:?'  ^''-l  :"''^"--'"'^«^«  ^'^'•'^»'<1  from  the  en.hrvo 
•  e  L  2''"'"'  7'l";'-;«"';-  -it»'  those  derived  from 
-  ..:    "'^""'•.'•'•-;';<-tn.ns  of  eourse  include  all 

,r    ■;    .'''*"'""■        '"'  ;'  '^   ''>'  ""   "'^'•''"^  "^'^''«"«. 


aj'es 


ore  nnpnruuu  for  this  purpose  thaii  that  of 
■^n  aiooe  piay-^  its  full  part  in  the  eoonomv 
i»-t    K    i..i..    „....;,    .^'.roriL'lv   .ir-ed    ,.v  tho^ 


"f"  n.iture. 


(  LA.SSJFK  ATI(».\ 
■It  naturalists,  Milne  lO!  wards  and  A 


tirvoiiif 


I  i  I  >  (icitiiin   of 


trassiz,  that 


.•fianitfeis  ar^  th.'  most  ininort^tnt  of  anv  in  tl 


;<77 


♦'tii- 


iUinialH ;    and   tliis  dort 


trt'iL-rally  befii  admitted  a^f  t.  ..„ 

.00.1  u'itli  riowerintr  plants,  of  vviiirh  H 


rniR   has   vorv 
rue.      Hie  samo  fact  held- 


-Kiiis  hav 
,1 


!«•  two  main  dm 


('  l«en  (ouiHled  on  characters  derived  from  fh. 
rmKrvo._on   tlm   numher  and   position  of  the  emi.rv- 


'IIU' 


li'a\cs  or  cotyledotiH,  and  on  tl 


i/i»Mit  of   tlio  jilurinjle  and   radicle.      I 


16  mode  of  «leveloj. 


n  our  di>.u«Mon 


Mi.ryol.,:ry,  „e  shall  see  why  such  charact.-r 
it)le.  on  liift  vievr  of  claf.siri<ation  tac 


i!:i:ihle,  on  liie  vi 
le  idea  of  descent. 


itly  uiclud 


•<  ai>>  so 


n;^' 


(  ) 


ur 


«■l■l^-sification^   are    often    jdainlv  inriuenced   \ 


i.iwi-  1,1  affinities.      Noti 


)\ 


■U-w.w  a  iiiiMii.er  of  charactt 
ui  itic  ca>e  of 


nriir    ca;i    t,e    easier   than    t. 


r-i  tommon  to  all  hird^-  i»ii' 
crustaceans,  such  detin:tion  h;is  hitherto 
.-en  found  imyK.sH.h le.  There  are  crustaceans  at  the 
"I'I'-ite  end.  of  the  series,  which  have  hardlv  a 
•  t^ar.icter  in  common  :  u-t  the  s|»ecies  at  hoth  end. 
from  beuiiT  plainly  alll.d  to  others,  and  the,e  to 
•M  -er..  and  so  onwards,  can  he  re^-o^nised  a.s  uneouivo 
al  y  l.elo,i^..n^  m  thi.-,  an.l  to  no  other  cla.s«  of  the 
\rt:culata. 

'--graphical  distrihution  has  oftei-  heen  used.thou.-n 
.'••r!,ap«  not  .,u.te  lopc-lly,  in  classifioatior!,  m.fre 
^-.ecially  in  very  large  groups  of  closely  allied  forn,- 
"•'"'""i.^k  insist.,  on  the  utility  or  even  necesvtv  of 
'■■■>  i-ractice  m  certain  groups  of  hirds;  and  it  has  heen 
".  '"v...    t,y  several  entomologists  and  fn.tanists 

I  inally,  with  resptxt  to  the  comparative  value  ..f  the 
w-riou,  ,^roups  of  sj^cies,  such  as  orders,  sulM.rders, 
urn  i,,..,  .sul>-families,  and  genera,  they  seem  to  he,  at 
■e^-t  at  pre,Hen  .  aim-  -t  arh.trary.  Several  of  the  l,e.t 
^-t•in.sts,  such  as  Mr.  Jientham  and  other,  have 
^troniriv  ,ns.ste.i  on  their  arbitrary  value.  in.-tances 
UHild  1,0  ^nven  amoni.-t  plants  and  in-ects,  of  a  i:rou,. 
■'!.,''"'.!:  T.l  ""•'^*  ';>■  \"-^''^'-^'^  natumli-t..  as  only  i 

i'Milv      and  this  has   been  <lone,   not   be<-ause  n,r,fier 
^♦'-^e.r.-h  has  detected  im}x>rt.int  structural  UiffereiK-<.s 


W;  ON    THE   ORIGIN    OF   hI'K{  IKS 

at  first  overlooked,  but  bix-au^naineruus  allied  ,,^1 
^'•h  sh^rUVy  d,rt-«rent  ^^raden  of  d.fferen.e.  l,a^iT>l 
Hul)s<>.(iH'iilly  discovered. 

All  Uie  lorefroin^r  rules  and  aids  and  diffi.ulties 
..la.s>:.hatiou  are  ex|,h.i,ied,   if  I  do  not  cnatly  derei 
■nvM-lf.  un  the  vu-.  that  the  n.tura!  s;>ten»  iAound, 
ondeseentwith  modiiicaUor,  ;  that  ihe'charartern  whi, 
i.aturalist.*  consider  afl  shonin;:  true  artinitv    l.etv»e< 

inhentod  ,rom  a  conm.on  ^nMit,  and,  m  m.  tar,  all  tr, 

ihT!  '  r  m"  "  r'T^T"^^ '  ^''''^^  community  of  descei 
O'  the  hidden  Inind  which  .uturalK.t^  havV  Wn  u, 
consciously  Keeking,  and  not  some  unknown  r.!.n  . 
creation,  or  the  enunriatjon  of  treueral  proj  -{,;„*,,  j^„ 
th.  n.,.,,  tt.n,^  to.^ether  and  .separatW  oojectn  mu, 
or  le.s.s  alike. 

Hut    1    must    explain    my    meanin^^     more   fuliv. 
be  .e^  e  tiiat  the  armnyevu-ut  of  the  Krou,«  within  'eac 
«i.i>s,   m  oue  Kubordmatiou  and   relation   to  the  othe 

'ItuST'f.^..f'''^>'  »^«"''^^^'K-1  i"  order  to  I, 
natural ,  hut  that  the  anwwit  of  ditfereuce  in  the  ..-vera 
.Hinche.  or  ^^roups,  though  allied  in  the  ^n,e  decree  ii 
'l-'d  to  the.r  common   pro;,enit<,r,  mav  differ  ^^reatly 

^^h.,  1    they    have    uuder^rone  ;    and  this    ii,   exi>resse< 

•y    the    (orms   bemK  ra,ike.l    under    different  ienera 

am.lies,  seet.ons,    or  orders.        'Hie    reader   wfll   1 

mder.stand  what   h  meant,  if  he  w.ll  take  the  trouhlt 

o    reternnu  to  the  diagram  in  the  preliminary.     U 

w.ll  8up,.o.e  the    etters    A   to    L  to  represent    allied 

genera,  which  l.veddurintr  the  SilunaueiH.ch   a nd  th^ 

have  descended  from  a  species  wh.ch  eJi.t  vi  a  ta^.^ 

k n..wnan  en..r  penod.     Sp,vie«  of  three  ol  dies.- ^^n^  a 

i;  ,  ;      VJ     ''^  ^'■^'-•'"'ittt'd  modified  de«oendant.s  tx, 

the  present  day,  repre.sented  by  the  liftoeu  ^en.ra  (a^  u, 

^^.on     he  uppermost  horizontal   i;ne.      Now  all  thel^ 

n.od.ru.d  descendants  from  a  siu^rle  ,j^.„^   are  re.. ^T 

-n,ed    a.-_  related    in    bhKKl  or   de  J!?!"-":    ^r/M'::: 

<U-^T.e  ;  they  may  metapnoricaily  Ik.   called  cous.nrto 

the    .une   m.llumth    de^^ree  ;    yet    they    differ    J.deJy 


<tf  ■  K'^iinj.i^C'.i^-tt:;?  ;,**«*-. 


CI^SSIFICATION 


37'-> 


^.^ld  in  different  de^e«,  from  eaih  otl.er.     ilie  fon.u* 

lesroiideu  from  A,  now  broken  up  into  two  or  TrZ 

ramJ.e.     conHtituU,    a    distinct    order    from  thone  ,1.! 

scoM.  ed  from  1,  also  l.rok.M.  up  into  two  famiJ.*^     W 

can  lh«  ox.«t.n^  «{H^-.es,  dosrende.l  fro,.,  A,  be  rank.-l 

n  th..  .ame,H.nu.  H,tb  tl.e   parent   A  ;  or  tho^  n  m 

,  wah  the  parent  I.       Hut  tlie  eiLsfn.^  ^ernis  ►-*  „" 

k'  .up{M.>e.i   U,  have  Wn   hut  sli^htlv   nw,dif,ed  ;  an  i 

it  *.ll   then  rank   w,th  die  parent -»renus  F;    just  i^^ 

"n^rl"'  t\"';V^"   ^*'"*^«  ''^'-"^  to\s]h:n.t 
^enerft.       N)  that  the  amount  or  value  of  Uie  ditfer- 
'•urcH  l^tween  organic  bein^rn  all  relat^^d  to  e.uh  other 
.1    lu.  ja„.e  decree  in  blood.   ha«  come  to  In,  H'ie  v 
hrftrent.        Neverthele«.   their    Ronealotrical   urraj^. 
mnu  remaui.   «tnrtly   true,    not  only   at    the  pre. 'nt 
'      r^^'f  ?"''    successive    f^eriod    of  descent.      U 
the  ,„,.d.he<i  descendant,  fron.  A  will  have  inherited 
M.me tlnu*.  ,n  common  from   their  common  parent^ 
will  all  Uie  descendant,  from  i  ;  so  will  it  be  wij,  li" 

;    ;'>d    "l?  hT'^  "'  <J«'-ridant-,  at  each  «ucce"ve 
c^H  d.      If,  h..wever,  we  choose  to  .uppose  that  anv  of 
Uie  descendant,  of  A  or  of  I  have  l^n  so  much  mo^  rted 
as  to    have   more    or    le*,    completely    lo«t    trace.    .^ 
the.r  ,.ireuta*fe,  in  this  ra>.e.  their  place*  in  a  naM,r 
cWMfK-ation  will  have  been  more  or  leCompl  tj h    o'  " 
-a^  sometime-  seem.  u.  have  occurred  wlh  exist  nj 
or^.-Hm«      All  the  descendaaU  of  the  ^eTn     F   ah   ^ 
|ti.  who  e  line  of  decent,  are  supposed  t^  ha v'eh^n 
ut  httle  modified,  and  they  yet  VL.  a  IX  "^. I  ' 
IJut  ti.u,  c-enufi,  thoujrh  much  isolated    will  still  ...  1 
.t.  proper  intermedin  po«iUon  ;  for' Tori;  L^^^^;^ 
Hitenneduite  iri  character  between  A  and    I    ^  ,^       n 
^'veral  jrenera  descended  from  the«e  two  ^n  ra   I  1 
have  inherited   to   a  certain   extent   their  ch"  r^-u  r. 

tnaiiiier.      If  a  bj-auchin^r  dia^rram  had  "«»  t-i.-  ■ ^ 

and  ooiy  the  names  of  the  jrroups  had  lienwHUeTHt, 

uave  ,r,ven  a  natural  arrangement ;  and  it  u,  notoriously 


wo 


ON  'nn:  orkjin  ok  spe(  jk.s 


II 

I  ! 


-ot  povsiMe  to  re,.re>CM.t  in  a  seri,-.,  .,n  a  flit  surfa.-e 
itio  afhiiities  which  we  diMuver  in  nature  amongst  th( 
'.euiL'.-  of  the  Mame  ^runj..  '11..!*,  „n  the  view  which 
Hold.  iU'  natural  .system  is  ^.Mifaloj^i.-aJ  ,n  it.  arran-e 
.nej.f  like  a  i.e.i,;,rree  ;  but  the  d..:,^reeH  of  n.odit^ratu,, 
^•liuJ,  the  dilff/ent  sjroups  have  underirone,  have  to  hi 
'xpre^^Hd  by  rankintr  them  .mder  dirferent  rto-rallft 
-'en.'ra,  sub- families,  families,  .ectinns,  orders  an.l 
'■|a>.-.fs. 

It    may   he    worth    whil,^    to    iiJuHtrate    thin   wew    oi 
lassifiration,  hy  takiiijc  the  rase  of  lan-uaijr^       If  wf' 
imssessed  a  perfect  pediirreeof  mankind,  a  trene^loincai 
..rranirement  of  the  raot-s.  of  man  wouhl  afford  the  best 
.lasH.fication     of    the    \anous    lanj-ua-es   now   spoken 
throu^rhout  theworM;  and  if  all  extinct  lanjr.Kiiies  and 
..1.   intrrrnHiiato  and  slowly  chan;,Mni;  dialecU^,  had  to 
t»e  mc  udi-d,  riuch  an  arranyen.ent  would,  I  think    be 
thf  ..nly  possible  one.      Vet  it  nn-ht  U^  that  sou.e  very 
ancu.i,t  lan-uaue  had  altered  little,  .I'ld  had  gneu  ri.,i 
•    '  ^    ii^vT   lanirua-es,   wiiil,t    others    (owintr    to    the 
-pieadin<r  and  subhequent  isolation  and  states  of  civilisa- 
tion of  the  several  ra.  e,,  descended    from  a  common 
ra,  e)  l,ad  altered  ipuch,  an.l  had  -iven  rise  to  mariv  new 
lanirua^es  and   dialects.      He  various  decrees  of  differ- 
ence in  tiie  lariiriia^res  from  the  vime  stock,  would  have 
to  !„■  e.vpre.sseil  hy  groups  subordinate  to  ^-roups  ;    but 
rhe  I-rojK'r  or  even  only  p„ssiblearranfremeut  would  still 
i>e  «eneAlo;:ical  ;  and  this  would  be  strictly  natural    as 
.t   would  connect  tofrether  all   Ian,  ..a^res. 'extinct  and 
.nodern,  hy   tl.e  close..t  affinities,  and   would   ei;e  the 
hluitutn  and  oritriu  of  e.i<  h  tongue. 

In  .onfirma^ion  of  this  view,  let  us  -lance  at 
ihe  cUsMificution  of  varieties,  whi.  i;  are  !.»'lieve«l  „r 
ni.own  to  have  descended  from  one  species  'Ilie^e 
i.-e  irrouped  under  spvcies,  with  sub  -  varieties  under 
•  arieties;  and  with  our  domestic  productions  several 
other  KT-yles  of  difference  are  re.|uisite,  as  we  liave 
■tH-n  with  piLH'ons.  The  or'"!!',  -.-.f  :]:t:  «TUt.-.=..-~.  -.i 
w'roiijw  Pubo'rdinate  to  groups,  is  the  same  with  >arie\i&s 
^-  -iiLh  specioM,  namely,  closentMi  of  dt-Hcent  with  various 


'"  "  i  II  llililill I I    II  |ii|l|i|MIIMi  I 


CL.\.s?SlFI(  ATION 


381 


de*^.-.-i.  of  moiinratiori.      Nearlv  the   H-im^   riile^    arn 
(oJowed  in  .-Lvsifvin;:  variotjps,  as  with  specie.  Author- 
havf»  msHlfd  on  the  n.'ressitv  of  .la'^.sintr  vanou.M  oii  - 
nalt.ral    iiiHtoad    of    an  artihria!   «vKtoni  ;   wp  are  mu 
t:oi,P,l.    lor  n,.ti»ii.-o,   not  to  .-la.,*  two   %ari..tieH  of  th«. 
pinf-nvple  to-r>th.'r,  mrrely  \>ecHuse  their  fruit,  though 
tl..'  nv^t  important  jiart,  happens  to  h..  nparly  icientir.ii  • 
MO  ot...  put.,  the  Swedish  and  common  turnips  ti.irether' 
thfMi...,  theeMuilcntand  tiiirkened  stems  are  bo  sun. i;ir' 
\M.afvor  part  is  found  to   he  most  roiKtant.  is  used 
m    .i.t...ni-    varieties:     thus     the     ^rent    aerirultur.f 
Marsfiall  >ays  the  horns  are  verv  useful  for  this  puriMw 
with    rattle    l,er^u<e    they   are    less  Variahie  than   the 
-hape  or  .-olour  of  the  hody,  etc.  ;  whereas  w,th  sheep 
'he    horns   are    much    leM    sernceahie,    l^cause    less 
•oi,.f;u,f       In  chssuitr  varieties,  J  apprehend  if  wo  had 
..  real    i.ediiTTee,  a  <renea!ot:ioal  <-la<v„irati<ui  woul.i    |... 
■niiv.Ts.uiy  preferred  ;   and  it  has  heen  attempted   h; 
->rne  authors.      For  we  mi^ht  feel  sure,  wlu-ther  tliere 
had  oeen  more  or  less    modifi.:ation,  the  principle  at 
.uhent^nce  would  keep  the  forms  to^eliier  which  »ert- 
luied   in  the  tm-atest  numher  of  points.      In  tumf.ler 
piK-fjnng,  thoujTh  somesuh-varietie*  differ  from  the  r.ti.ers 
.n  the  important  character  of  having  a  lonjjer  »>eak    vet 
all  are  kept  totrether  from  having  the  common  hahit 
■.ftumhlinir;  h,.t  the  short-faced  breed  has  nearlv  or 
-juitehrst  this  hal.it;  nevertheless,  without  any  reasoning 
or  thmkin^r  on  the  suhject,  these  tumhlers  Are  kept   in 
he  s.->me  jfroup,   lM*oause  allied  in  blood  and  alike  in 
jome  other  resjK^ct*.      If  ,t  could  be  proved    that  the 
Mot  e.itut  had  descended   frum  the  NWro,  I  think  i.e 
-oiil.i  W  classed  under  the  Nej^ro group,  however  much 
'"  m.^ht  ditfer  m  colour  and  other  important  chara.  te-  - 
"om  n«*rroes. 

\J  iti)  «i»ecie3  in  a  s'ate  of  nature,  every  naturalist  has 
H.  fact  brou^'ht  descent  into  hi.s  classification  ;  for  he 
I'ldude.  in  his  lowest  ^ade,  or  that  of  a  specie,.,  tlie 
•-'•- «~?es  ;  a:;d  l;;r^  er,orijiousiy  these  sometimes  differ 
ill  tlie  mo«t  iniporuut  characters,  ia  known  to  ever*' 
riSturxJirt  ;  scar.eiy  a  single  fact  can  be  predicated  in 


3n2 


ON   THE   ORUilN    OF   SrFA:iKS 


comrno,,  of  the  rnal.^  and    ht.r.„aphrodu«.-  of  r^rt; 
r.mpHe«,    when    .vi.It,   and    vet',...  one    ,inZ7 

u.eMJvrral  larval  .t-wres  of  the  Kame  in.i.vid-iaj  hole, 
.u,.h    ,hev  .n.v    d.tfer  from   each   other  ar.d    frorn 
ad.ilt.    an  he   nk.-.vne  mrlndes  the  so-.-alled  alt.rni 
..-..era hoHH  of  >f.enstn.p.  .  h,ch  ran  onlv  ,n  a  '    h  "i 
-r,.e    »H.    ronsMLTed     as    the    .an,e     individnal 
unhide,    monsters;    he   inrlude.   varieties,    not   M.le 
.e.aa«e     hey  do.ely   re.vMnhle  the  parer.t  -  f<,rm      b 
H..aasethey  •.redeseended    from  it/    H.  who  Miev 
t^.it    the  cowsl.n  ,«   descended    from    the  primrose    , 
••-'vorsely,   rantcs  them    to.^ether   as  a  s;,Lwe  spe^.'e 
;'"i    /rives    a    .uis\(.    definition.       As    soona^    thn 
-h,   oan  f;.rn,WMon<,.-h.nthu«,  Myar.th."^:^  r^ 
<t  im)     wh.ch    had    previously   heeu   ranked   :.s  thrc 
i-mrt  ,'enera    were  known  to  he  sometnnes  prod   c" 
"-he  H.ame  Hp,ke.  they  were  immediately  ir.e  uded  ' 
'«  -it);,'^le  speries,  ■' 

As    .lescent   has    univer<«illy   heeu    .:sed    :n    .  lassi,, 

'..-ther  the  md.vdnals  of  the  same  .pecie..   thouH 

he  males  and    females  and    larv*   are   somet  mesex 

rcmely  d.t^erent  ;  and  as  it  has  heen  used  in  cWin 

ar.et.es  wh.ch   have  undergone  a  .ertan,,  and  «ome 

tmes  a  cons.deraMe  amount  of  modification,  mav  no 

hH  same  element  of  des.ent  have  been  unconsc.ou 

u>.  i    .n   ^roupn.ir  spenes   under  genera,   and   ^ener 

.H.  er  h„'her  groups,  though  in  these  case,  the  modi 

hc.uion   has  been  .^reater  in  decree,  and   has  taken  . 

<..)..er  tm,e  to  con.plete?     I   believe  it  has  thu!,    .eer 

u  u-onscously   used  :  and   only  thus  car.   I   unde.-sta.'d 

Uu.  several  rules  and  tjuides  which  have  been  followii 

bv  our  bes    systematists.      >Ve  have  no  written   pedt 

Kr.e.     we  have  to  make  out  community  of  descent  bv 

resemblances  of  any  kind.       I-herefore  we  choose  those 

ha  a.ter.  wh.ch    as  far  as  we  can  .iud..e.  are  the  l^ 

l.KHlv    to   have   been   n.o.iitied   in   relation  to  the  c^ 

H.t.ons  of  l.te  to  which  each  .pe<-ie.s  has  been  rll.rZ. 

'•^r.so,i.      Kuu.meaury  structures  on  this  view  are  a^ 

t...K.  ,.    or  even  sometime-  ^»etter  than,  other  oart.  of 


^f^^»l':fPr? f.?ir.£^B!»ii2BK- 


CMSvSIKK  ATION 


.383 


thf  o-sfnni«<ati(.M.      W'e  c.%ro  rmt  how  friflinp  n  chamcter 
HMv   tK»      let  It  }>e  t!.(.   ,nor.>  iiiriortion  of  the  ,-»n-l.«  of 
'  ^<'  Mw,  thp  manner  in  which  an  iri^prt'««  winjr  i„  f„id.-«l 
••'•h.«;h«T  thp  skin   he  roverwl   hv  hair  or  fj^athfr**     if  it 
t-'ovul  thro.i;:hmit  manyan<I  different  Hpocips,  e«m.riallv 
tlin.e  h:i^u^tr  very  diff.-rent   hahits  of  life,  it  a-ume;. 
'i_'li    value;   for   wp   rari   account   for   its   presence   in 
^'  m,.ny  forms  with  mi.h  different   hat-its,  .mlv  l.y  it* 
irihmt.inre  trnm   n  <ommon   parent.      We  mav  err  in 
!liw  r..sj.Prt  in  n-Tird  to  single  points  of  structure    hut 
^*h.-M   -evor:.!  chara.ters,  let  them   hg  ever  .o  trif'iinir 
nr,=,r   tr.L'otlier   throuffhout   a    Iar<re    oroup    of   heininJ 
hv.-inir  ,j,ff,.rpnt  h.ihits  we  may  feel  almost  sure    on 
the  thoory  of  descent,  that  these  charact.-rs  have  l,,.en 
iiihonN.,!  from  a  common  ancestor.      .\n.l  we  know  that 
iurU  corrHatcd  or  n--re£rate<l  characters  have  espec.al 
>il  :t»  HI  classification. 

^^'e   can    undersfind    whv   a   sj.c.  ies   or   a   L-roup   o» 
^i'cr),.,  may  depart,   in   several   of   itj^   mo^t   important 
-liY  '•;»>n,tics.  from  its  allies,  and  vet  he  safely  da.sed 
«"h   twem.      Hii,    may    he   safely   done,   and    is   otlen 
dorio,  as  lon^  as  a  sufficient  numher  of  characters    let 
tl;<:ii  i.e  ever  so  unimportant,  hetravs  the  hiddeji  h'nuH 
Of  CMmmunsty  of  <iescent      l^t  two  forms  have  not  a 
s)iirJe  character  in  common,  yet  if  these  extreme  forms 
•vo   connected    to-ether    hy  a   chain    of  interme-jiate 
I.  "  ips,    w..    may    at    once    infer    their   community   of 
'i'  ■';ent,  and  we  j.ut  th.-m  all  into  the  same  d.xss       .\s 
'-find  or-:u.<  of  hiirh  physioloLHcal  importance     those 
'-  ■•uh  .ene  to  preserve  life  under  the  most  diverge  cn- 
•f  tiHPs  of  eiiHtence-are  ij-enerally  the  most  con^-ant 
«p  .ittach   espe<-ial    vaLie  to  them';  hut  if  these  <ime 
•T.Mns.   in   another   -roup  or  section  of  a  jrr„„p,  are 
'«•   nd   to  differ  much,  we  at  once  value  them   l,.<s  in 
<"^  rlx..iticat:on.      We  shal'  hereafler,  I  think,  clearly 
'»»•   «iiy   emhryolotrical    characters    are    of   ^„ch    hi^h 
!!!r.''l!!!!.'^.?'Z  ^'J^P"''^'^'=7-       <'P<5raphical    distn hut-on 

.n?.K   "inTV.-':,..^       .  ..^U^    ..^^^.^ij^   -^^j^^^  ^.^^    .^^   Cia>MMff 

■^r^a  and  w-dely-distrihuted    ^renera,  liecause  all    the 
•'.K  ie«  of  the  same  ^ntn,  inhahitinr  any  di.stinct  and 


nii4 


<'N    JJIK   OIUtilN    OK   Sl'i:(:if> 


.-.la;>yi  rv^um,  havo  in  all  pruhabilitv  dt.«,-e.i.Io.]  f 
iJiH  R.Tm<'  ji.i rent's. 

^W  ran  uiif)<'r,Uri.],  <.n  thcsp  vi..ws,  tlie  very 
P'.rtyit  ci,>tin.  lion  iK^twr.-n  real  affinities  and  analo- 
o-  ri.,a|,t,ve  ro'-pnihlancrs.  Umarck  first  call.-.l  at'i 
f.oi,  totl.Kd.stin.ti.m.and  l,e  has  Uevn  ably  loll..^ 
U}  Mar.iMv  an<i  (.thrrs.  Jl.e  rrM-mMance,  in  Uw  «I, 
o<  <<  o  }.,..iy  an.l  in  the  fin-like  ant/^rior  liml-n.  hotw 
h-  d.urone.  which  is  a  i-'u  la  .Irrmatuuii  animal,  i 
t'M-  «  half,  and  hrtw.en  hoih  l[,.-.e  mammals  and  fisl 
1"  ;.n.il<,Ku-al  Amon-.t  iiiMTts  thrre  an-  ininim-r, 
mstarices  :    thus   U,ui*us,   misled   hy  external  hi.,,. 

atn-es,   a.-tually    da i    an    Inuiiopt'erous    in^vt  '.. 

Mu.th       \\  ,.  M>e   ^.)methin>r  of  the  same   kind  even 

...,r  .lomestir  v.rlrt.es,  as  in  the  thirkened  ^tcrn.  of  l 

enmmnn  and  swr.lish  turnip.      n,.-  r.-M-mhlance  of  1 

Knyn.MHHl  and   ra.ciiors,.  is  hardly  mure  fanciful  tli 

the  analogies  whirl,  have  heen  drawn  hy  some  auth, 

hetweer.  very  .]i^tiMt  animals.      On  mv"  view  of  d., 

acl.M.-    .em^r  of  real  importanee  for  .  lassification,  oi 

in  so  Mr  HH  they  reveal  de.rent.  we  .  a-i  rlearly  und( 

fitan,]   ,vhy  analo-iral  or  ad.n-♦i^e  rharactor,  althou 

oi  tie  utmost  iirij.orUnce  to  tlie  >velfare  of  the  Umii 

are  aiiiiost  val-ielesa  to  the  ^\ .lernatist.      For  anima 

'"'i'm-inir  to  two  most  di>tu.et  lines  of  decent    m 

r.adiiy  heeome  adapted  to  similar  eonditiou-.  and  th 

ass.nne  a   elose    external    n->emhl,in.e  ;    hut    such    t 

semlnances  will  not  reveal     will  rather  tend  to  conce 

their  blood-r.'lationship  to  their  proper  lines  of  d.'s.vi 

ne   .an   al<o    understand    the  apparent  paradox,   th 

ti.8  v..ry  ^mv  characters  are  analotrical  when  one  cla 

or    order    is    .-ompan.,!    with    another,    hut    trive    tn 

ntfiiiitu-  when  tiie  members  of  the  same  class  or  onl, 

are  compared  one  witii  another  :   thus  the  shape  of  tl 

body  and  tin-Iike  limbs  arc  onlv  anal-.iric  ,1  when  whah 

are   comj.arcd    with   fi>hes,    bein^-  a.lapLations   i,,    hot 

clas.rs  for  8wimnnn;r  through  the  water  ;   hut  the  shar 

!!.l,l.!w;.   ?^/   *"•',, '""';J'1^»^'    l'"'>'^    w-rve    as    rharactei 
.  v  .!■!!.  !!>.|r    r:;e  -^i; . . .  _  !^.^.  y^j..^_.^   .j^^^  hcv.Tal   mcmbei 

ot  Uie  wtiale  family  ;  f,,r  Uiese  cetaceans  ajrree  in  i 


iJ>s^ 


?-*i  -- t-"!'-"! 


4fe'^^.T'/^-^fc^I,7^ 


(  LASSIFK  ATION 

tMV    c-Lira.„-rN.    ^n-.-.t    arid    Hrnall,    that 


<l«".!.t  that  tlii'v  fiave  „ 

"«'.lv  aii(i  -fnirturo  of  limf.s'f 

'*^<'  It    i.s  witli    fi.sht 


.T8A 

nUi-raed  their  ^etu-ral  sha,K,  of 
ntni  a  rornmoii  an.  ,.!»tor. 


\-    rnt-niherM    ..f   .iistiriot    .lasses*    h 


l;i|it>Ml  iiy  mj 


i'<-«' 


ia\»'    oft^'u    I 


I'Mrlv   -iniihir  finiiin>t 


'<li4rht  nio.lificatioim  to  1 


>fVl\ 


trie  tliri'»'  el»' 


"MTS.-    to    ililllhit     f, 


h 


i|iM  iiinl«'r>taii(I  } 


I'-iitxot  iaiKl,  air,  and 


i\«'  iinihr 
T  iri«itaii(p 


"w  It   is  that  a  ri 


ha>  •.orji.-iuin's   l,i.,.„   obs,.rve<l    \,v{ 


111  <ii 


tirirt  .lasses.     A  Mafuralinf,  struck  \ 


watiT,      H-.- can 
"riUTical  parall».f|^rn 
w»Mvi    the  •<iit>-urniii»- 


..er- 
■lisrn 


"f   this  naturi' 


or    vi,ikiii{r    t)ie   val 


any  one  cla>s  hv  arhitranl 


lie 


ot    tl 


'»y  a  |..iralirli>rii 
y  rai^iiiir 


.'ami 


our 


e\ 


lia»  liitht-rto  fteen  art 
I'.iralleli^ni  owr  a  w nie  ranir,. 
Mi'i"-»ry,   .luateniary,  and    h 
proi.iMv  armen. 


iM'    irrou{w    in    ,,ther  <1 
[.enenre    ^hov*8    that     thn    val 


a.'.sc 


arbitrary,),   could   easily  extend   tl 
and  thus  the  -«'}iteiia 


uaiiiMi 


le 


■rnary  cla.Hsificati(»ns   } 


ry, 

ia\e 


t. 


As   tl 
■'"iiirin:;   to   the   lart.M 


!•'    moditled    descen.lant>i   of  d 


oniinant    species, 


advanra^re^,    which    n.;.<if    tl 


r  >r..„era,   tend    to    inherit    t 


h.-! 


'"iir    iar^e    and    their    jiarents    d 


'♦*    *,'rnii|,s     to    which     th 


e\ 


aiiiMisf  «ur;'  to 


MK.re   jda.es   in   the   ecor 
and  n 


pread  v  idely    and  Ut  sei 


ominatit,    they   are 


/e  on  nuire  and 


iiore  dominant  trrouj.s  thus  tend 


""iiy   of  nature.     The  1 


irjfer 


int'    lu    si/e;    an<l    they   < 


-u 


■'Her  and   teelder 


'i  ••   fact    that  al 


trroufi 


III' hided    und 


er  a   tew 


'•>  K«»  •>ii  increaj- 

•onse,_,uently   supplant    many 

Hi  account  for 

extinct,  are 


11 


liiis  we  c 


or^misms,    recent   and 


<-l.t-ses,  and  all  in  (> 


*rreat   order-,  under  ntill   few 


II, 


h<.w    few   the   hi.rl 


♦•  trreat  natural  nyste 


er 


m 


f  ..«  widely  spread  thev  are  tl 


tfJier  groups   are   in   numl.e 


As  si 


ow 


'•K't  i>  >trik 


iiiif,  that  th'e  d 


irout'hout  the  world    tl 


and 


tiide<l 

n  the  ve-etahle  kiiiirdom,  as"?  \ 


ii'^uiyle  inject  helonjrintr  to 


iM-overy  of  Australia  h 


IS  not 


a  new  claMH  ;  and  that 


I 


las  addi'd  only  tw 


111   the  chapter 


<>  or  three  oriiers  of 


earn  fr<.m  Dr.  Ho«.ker 


on  jfpolojrical  «ucces.sion  J 


small  si/e 


t-l<..w.on  thepn;;::;,K::V::::^'  «uc.es..on  J  attempted 

-; -..i  nun.h  [n  character  iluri;;;  tL:' i:;;;;:.^:;  ■::l!i 

■—  ot  mod.t,cat.o„,  how  it  i.  tliat  the  nrore  anaeu 


^^Wl"^ 


386 


ON    J  HE   ORKilN   OF   M'EdES 


fnnnH  of  life  ofton   |,n»stMit  rl.ara.terH  in    somo   si 

•ijvre*,  mternuMliato  Ih^Uvou  ex.sti.iif  ,fro.j,m      A 

ol.l  and  ...lernuMluite  pan-i.t-forr...  hav,„^  o!-.  asioii 

trainnnm..!   to  fl...  pre^,.,.,   ,|av  .lpsr,.,i.lanU  hut  1 

in.Kl.h...|,   will    K,vo    t<)    us    ou'r    Ho-ralle.1    os.ulan 

aberrant  jfro.ips.     -n,,.  m«.r«  alM-rraiit  anv  form  is 

trn-atiT  jnust  Ikj  the  .nuMher  <.f  .-o.ine.-titi,^  forms  wl 

on  my  tli.-ory  have  heen  exterminate*!  and  utterly  1 

Ami  we  have  M.me  evidence  of  ai.errant  forms  ha> 

Hurfere.l  severely   from  exti.j.-tion,  for  they  are   i^ei 

ally   represented   hy  extremely  few  s,KH-,e;  ;   and   s 

H|M.nes  jis  d*.  ocTur  are  «:enerallv  very  distinct   fi 

eacli    other,    which    ajrain     implies    extnu-tion 

jreneraOrn.thorhynch.i.s  and  J^.pidosiren,  for  exami 

would    not    have    heen    less   aherrant    had    ea.-h    h 

represented    l.y  a  d(.zen  Hpecies  instead  of  hy  a  sin 

one  ;  hut  such  richnos  in  sjM.cics,  as  i  find  after  ,*, 

Mnesti::Ht.on,    does   not   c(,mmonlv   fall    to   the   lot 

al.erra>il  jrenera.      We  can,   I   thii.k.  a-.-ount  f..r  t 

Jact  only  hy  hu.kinir  at  alH-rrant  torms  an  failijiif  jrroi 

««n.|u--re.i  hy  more  .successful  comi)etitorH,  witli  a  I 

mem  hers  preserved    hy  some  unusual   coincidence 

favourahje  circumsUmces. 

Mr.  Waterhouse  lias  remarked  that,  when  a  memi 
UeUmaiun  to  one  ^roup  of  animals  exhihit^  an  affin 
to  a  quite  distinct  irmup.  this  affinity  in  most  ca.se» 

ireneraland  n..t  s; ,a]  .-  thus,  accordi'njr  to  Mr.  Wat 

house  of  all  Kodents,  the  hi/cacha  is  most  neai 
related  to  .Marsupials  ;  hut  in  the  points  in  which 
approaches  this  order,  it.s  relations  are  general  a 
iM.t  to  anyone  marsupial  s|»ecies  more  than  to  anoth< 
As  the  points  of  afh.nty  of  the  hizcacha  to  .Marsupij 
are  helieve.l  to  Ihj  real  and  not  merely  adaptive  th 
are  due  on  my  theory  to  inherifm.-e  in  commo 
Iheretoio  we  must  sup|^se  either  that  all  H.KienI 
including  the  hizracha,  hrandied  off  from  some  ve 
ancient  Marsupial,  v.  Inch  will  have  had  a  character 
some  d..irree  intermediate  with  respect  to  ;U1  existii 


M.J— :..i 


i-otii     ilo.ients   and    Marsupia 


l.ranched  off  from  a  cmmon  pro-.-nitor,  and  that  1m)1 


m^ 


<il#-S^ 


::'m^s^^^^^7h^A 


trruupfl  have  sin 

ilivertfeiit  direclio 


CLASSIFICATION 

•-e    uii.lerK<tn«    much    mo.lificat 


lat  Uio   I 


th 


o  c 


;hara<'ter 


iia  I 


Mn.     (  Hi  eithor  vi«w  we 


387 


loti    in 


lar* 


of  its  at 


retained,   \,y  inheriLa 


niay  Nuppu^e 


ifieiit 


"re,   njort} 
than   have 


rojfeui 
"....-.  .M„,e,uH;  an.l  therefore  it  w,ll  not  he  H.H'ciallv 
niate^  to  any  one  ex.stin.^  Marsupial,  hut  i.Inv  • 
.all  or  nearly  all  Marsupials,  fr.'m  hav.n^  ,«r  in  - 
reu.ned  the  character  of  their  common  proje  nfo  ir 
M  an  early  memJ>er  of  the  »f roup.  ( )n  tl  e  oSe  hand 
of  all    Mar«up,al..  an  Mr.    \\  af'erhouse  ha.  r^n  a  i^t 

spt.ie«,  f.uf  the  L-eneral  order  of  HodenLs.  In  this 
.ase  however.  ,t  may  Ik,  strongly  suspected  that  the  re 
M.,Ml.lance  ,h  onlv  analogical,  owin^  to  the  pf.at  .„  '« 
Kiunjfl,e<-ome  adapted  to  h.hi.s  like  those  >f  «  {.  ^nl 
e  elder  l)e  (  ando  Je  ha.  made  nearlv  similar  ohserva. 
.1  .  .s  on  the  ^.eneral  nature  of  the  aHinities  of  d.s^mct 
oniers  of  plants.  "isnnti 

<>!'  the  principle  of  the  multiplication  and  ifra<lua 
'iivereenre  ,n  character  of  the  spe,  .s  de^cende^H  mr 

'■erit-uno  of  some  characters   in   common,    we    can 
iHiderstind    the    excessively    comnle*    ,,..«    .^a    r 
acuities  by  which  all  the  nLZr!;  ^^if 'L^tmij': 
"r   h,^her    ^roup    are   connected    to^.ether       hort/.^ 
'ommon    i«rent    of  a   whole   family  of  s,K.cies     n   . 

un.npH,  H.ll  have  transmitted  some  of  its  characters 
■n..dified   in  various  ways  and  det'rees    to  all     .?A  fx  ' 
.^veral   specie,  will   cc;n.se,uenrry Te'    elated   "'each 

other  by  c.rcuit«,uH  lines  of  affinity  of  v..ri ous   len'Th 
-  may  l.e  seen  i„  the  dia^^ram  so  often  re  er  e  Vo 
-Hintmjf   up  through    many   Predecessors      A     it     s 
•^^ou^U^^\  Hlood-relationship   l>et«tn  \i:^ 

.•;^^    7.    fi  J"*^  ^^  ""'y  ""'^'^^^  and   ""''>«   family 

•uL!   I     r  "."^   l^-  *  '^''""^J"^^*!  tree,  and   almoin 

'.■M>Oss.Me  to  do  this  without   this  aid.  we  car.  ..I.Z 

-  -.u    uie    extraordinary   difhcultv   which    natur'ali  ' 


s    af!initie«    which    they   p^-neive 


'iiai: 


ram,    the   varion 


3»{0 


ON    TMK    OKKJrN   OF   SF'K(  IKS 


I 


h«"tw..pri  til*,  manv  lu;n^'  mihI   ..xtiiict   nu-nih«r«  ..f  t 
»*atii.«  irri'.it  ii.it  II r.il  cl.i-s 

Kxtiii.  t„„,.  a.«*  >»..  h.iv..  K,.,.ri  in  the  fourth  cJnr.ti 
l.;i-  jnav.-.l  at.  irn|M,rUiit  j.irt  in  .l.tiniriu-  aii.i  v*i.l,.„r 
tfi..  Mi(.Tv.il>  U.t«,.,-ii  U„.  M.v,-ral  ^rr...i|.s  in  ...i,l,  ,  U 
^\.•  tnay  t),.,.,  a-vouiit  ,.v.-n  f.-r  th..  di.-tiMctn..^^ 
v.h..l.«  .•i,,s.».M  fn.m  .'.,},  ulh..r  f„r  itmtam-e,  ,.f  l.ir 
from  Jill  otiier  v,.rt.-t.r.if««  auniuiU-- l.y  ih«  |„.I  ..|  tli 
matiy  aiicifrit  f..rtn>  of  lite  },ave  Im.,.ii  iitti-riv  1... 
tlir..u-l.    Hhioh    tl...    rarlv    i.r..ir,.„itoM    of    l.inU   w,. 

tortiM-rlv   cniMMMti-.l    witli   tl .,rlv   pru-.-nitorn  of   tl 

otlMT   vert.O.r.it.'  (  I.i^m.m.       I  h.-re  I,;..   l,..,.„    l,.,.   ^„t, 
.•xt.rutio,,   of    tl,,.   form^  of  lifr   «f  i.h   ..ii.«  roiiiMMt. 
h-l.rs   mtl,    l.;,tra.-hiat,s        Hmto  I.,.,   I.,.fn  Htill   le<- 
M.ni..    otlMT  .•la^>.-.   as    i„    tl.at    -f  fl,..  (  n.Ktami,    f( 
h.T.'  the  nio^t  w..ii.l.Tfully  diverge  forrns  are  utill  ti« 
toiT.'M.er    by     a   lot,-,   but    hroken,    rhait.    of  Hffi.ufie 
hxiiH-tioii   has  oulv    Kfparati'.l    trroups  :   it    ha.s   l.v   i 
riM-uis   n.a.l,.  tliern  ;   for   if  overv   for.n  whi,  li    lia^ 'pv* 
live.l  oil  tlii^eartli  woie  Huddeiilv  to  rrapjM.ar    thoutr 
It  w«.ul.i  1...  .|uito  i".po^«iMetotfivfd..tiiiitioii.  I.vwhi.- 
each  ^rroup  rould  Ik;  .li^tintrui^lied   from  otlu-r  trrouoi 
as  all    w.uil.l    »,l,.,..l  toirethfr  l.y  >teps  ax  fii,«  a«  thu. 
between    the    tuiest    existiiiir    varieties,  iievertlielevs 
naiiiral    rlasMficatioo,   or    at    least  a    natural   arratiffe 
ment,  wouM  he  po.*ihle.     We  shall  see  this  hv  turnir. 
to    the  .liHirra.n  :   the  letters,   A    t..    I.,   may   represe,, 
♦'lev en  .Silurian  jfenera.  Mune  of  v,hirh    have   priKlure 
l.tr-e  irroups  of  rno.iitie.l   <les,-en,lantK.        Kverv   inter 
n..-.liate   link    U-fween    these   eleven    irenera  a.i.l    the! 
prin.oriiial  parent,  and  every  intermediate  link    m  ea.1 
l.rainh   and   snb-hrar.rh    of  their  de.rendants,  may    b 
Mippose.l  to  he  still  alive  ;  and  the  links  to  be  em  riiiea 
those  iH-tween  the  finest  varieties      1,,  this  .-ase  it  w„ul. 
he  .juite  iT,.i«..Nible  to  irive  any  definition  by  whi.  h  th( 
^everal    members   of  the    several  -roups  rould    Ik"  diK 
tiiijfuisbe.l  fn.m  their  more  immediate  parents  •  or  tbes, 
ua:enfs  from    their  ancient  and    unkiio.Mi    proL'-nitor 
^.t  Ti,e  u.ilurai  arrati-emeiil  in  the  diairram'would  ^til 
hold  Koud  ;  and,  on  the  pruidpltj  of  mheriLancr,  all  thi 


^-.  V  4,'       J' 


■  v-- 


hM^-iMmi^^f, 


(  I.AS*.IKI<  ATFOS 


•wj 


•t  th« 


f,,r-M«  .l«T.«ii.lwl  trnm  A,  ..r  troni  I.  would  linvf*  h4m„»« 
'iiili;:  ,11  ((inuimu  In  :t  iri'i-  wh,.ui  -(.frily  this  ..r  'h:tt 
iTaii.  fi.thiniifli  .It  tlii'ri.  liial  furk  tJu- two  unit;- an.l  Mt-id 
?i>L'»'tl,..r.  We  roiiiii  iiDt,  .1-  I  lian.  sanl,  .|#,t,t,,.  thrt 
■■••\»T.tl  i:ruii|H  ;  t.ut  wf>  (•••■iM  pi<k  out  tv|..'«,  ur  tcrini., 
r.-pr.>-Mi!iiur  most  of'  the  rh.irart.T-  i.t  .-ail,  t'n.iij,, 
-ii.'ther  lar:;..  or  -irii.-ili,  itiui  thus  jfnt*  a  tM'ti.'r:tl  uli-.i  oi 
■h«  kftlue  (>(  tl...  (liif,.r.'iir»'H  hefwren  thi-rii.  1  hi>.  h  w  hnt 
«e  Khi.iiiil  l.e.lriv.Mi  to,  if  we  were  on.t  Uxiiir,  ♦M'd  in 
.••ill.'.tiinf  Hi)  tli».  »orm«  HI  any  cla^^  ^Uuh  ha\e  1iv»hJ 
throii-hMiit  nil  tiriii-  aixi  «(.»<•♦•.  \\  p  »h.ill  tertainlv 
iifver  Mi.(»'»>d  in  niakirnj  ho  fKTfe.t  a .  ollf.-tion  :  rif^er 
fh.'l..^-.  in  rtTtain  .  ia«M-,  w«  are  tetidunr  m  thii 
'lire<tu);i  ;  and  Mihir  K.i*»ar.ls  hns  lati'lv  inwistpd,  iti 
an  al.le  pajx-r,  on  tlio  lujfh  miporUnrp  of  lookintr'  to 
typi's,  wii.nher  or  not  »e  can  -.pparate  ami  dehne  the 
4fruii|n  to  which  ttuch  ty{>et»  U'lotn;. 

finallv,  we  have  R«»en   that  riatiir.il  -eli'.  tion,  whi.-h 
rPMilti*    from    the    htnijfjfle    for    exiM»-iK-f.    and   whn-h 
almost  in.-viiahlv  induces  extinction  and  divtrtfence  <tj 
charH(r,.r  m  the  many  descendants  from  one  dominant 
|mr»Ma- species,     e.x|ilainij     that     trr.-at     and     univer^l 
tc.;iiire   in    the  affinities  of  all  organic  l»ein*:«4,  namely, 
their  HuiM)rdination  in  jfToup  under  jfroup.     V\  e  use  the 
el'-ment  of  dt'srent  in  clan^intr  the  individual  of  U.th 
wxes  and  of  ail  a^es.  altliouiih  havinif  few  characters  in 
cc'i.mon.  under  one  s[.etie8  ;  we  U(««  deM-entin  cla-oflin^ 
a-knowledued    varieties,    however    different    they    may 
h«»  from    tlieir  parent  ;    and    I    helieve  thi-  clement   of 
d.-sc.-nt  !•*  the  hidden  bond  of  connection  which  riaturAl- 
Nr>  have  soiijfht  under  the  term  of  the  Natural  Sytcm. 
( >n  'iiis  idea  of  the  natural  system  heiii^,  in  so  (ar  ait  it  han 
I'Wii    |K'r!ected,   i^eneal<»);i<-al    in   its  arranirement,  with 
the  ifnide*i  of  dirference  l»etween  the  d»*scendant.s  frnrn 
i  common    parent,    exj.re^swl     hy    the    Utiii-.    ir„,K.ra, 
fimilies.    orders,   etc.,    we    .an    underbuild    the    nileJ 
J*  nch  we  are  compelled  to  f.dh.w  in  our  datsitiration 
•-  -  ra::    .i;:!urs:a;i';  ^fiv  ««  »ainr  certain  re-.«'miiiance.i 
fflr    morf    than   others;  why   we  an-  j^rmitteu   to  u-^ 
rudiuient^ry   and    useless   organs,  or  otiier*.  of  trifiiriij 


n,jy 


M 


.y.m 


"N    THE   OniC.ls   OK   M>K(lK.s 


-'I:,,;  ;,'::r;':,!::;.:T;:L;rr;r::::\r'-' -"'t 

<  i«MrIv  SCO  how  It  H   tilt  all    liv;,,  j      '  •       '  *^  ^ 

.  ^era!  n,ernl,er>o,  ea.h  das.  are  n-niXil  n^  l 

look  to  some  unknown  plan  of  Coat  .mw.  ^1       v 
f"  ",ako  «ure  hut  .lov,-  pn^ress.  '  ""'•'  ^'"i 

I  .11  /I    (Uii(>r   ij,    (dp  orpfn.ral    '1   •1.1    «f  »l 


«nr.  au.i  for^r   .        '  ,.     ,1     -^-y"*-.  '  '•^  f-n..  of  the 

H-wh..an.o..;;:,;l;^:!-.-'.';;;;t-n.j.^^^^^ 

^"•"•^^^,  w.ioly  ,i>tf.>r..,u   ani,n:.i.        \\>  s '^    I,'' 
^r^  .aw  M  th.  .■o„>tr,u-tion  of  th.  ,no:th".nr  """ 


what 

Pi'.;. 


I  nco^nff 


"pnJ^''"""/'**^"7^''  thar.   the  \mn^'n^.vU   U,.. 


^^. 


'l|hr|^^^^^^^.;ll^:^'3 


MOKI'HOI.OiJV 


:m 


ot.<>  of  a  \*op,  or  l.ui:,  and  the  trn-at  jaws  of  a   l^M-tle?— 


■  ft  al!  t}ies«Mirtjriii>,  scr 


tre   forriie<]    l.v    iutiiiitelv    t 


viiijf  tor  such  (liffiTfut 


iiinieroim    nwHliticatioi 


|iiir|iosc*, 


IS    ot 


m   upper    l:p.    maii.iil.Ies,    ari.l   twr,   pairs    of   maxill* 

\!i.i  ..-oijs  lauH  co\eru  the  r.,rmtru.fioM  oftlu'  n.-.uths 

Ami  lirni.s  ot  rrustareatis.       So  it  im  with   the  tlowpr^  of 

[tl.-iiir>. 

Not  hint'  can  t.o  rnore  h..p,.!e<s  than  to  attempt  to 
e^:,la;ri  tMs  similarity  of  pattern  in  memhers  ot  the 
virno  .liN-.  hv  litihty  or  by  the  .ioetrine  of  final  rausc- 
1  IP  hope  esM.es.  of  the  attempt  has  hcen  expressly 
lm:;te<l  hy  (  hv,-,,  1,1  his  most  interestinjr  „„rk  on  the 
Nature  of  l.iml.,.'  On  the  oniinary  view  of  the  inde- 
i.eM.leii^  rreation  of  ea.h  heinir.  we  .an  f.nly  say  that  so  it 
•'  ;  t/iat  It  has  ^o  pleased  the  (  reator  to  ronstnict  eaeh 
inni.'ii  and  plant. 

1  no   explanation   in  mp.nitest   on    the    theory  of  the 
natur.'il   heleetion  of  su.eessive  sliirht    mod-firation«  -~ 
'.i.'h    mo.iifi.ation    henitr  proriLihle  in  some  way  to  the 
"H..|:ried    form.   t„jt   often    affe.-tinjr   hy    correlation    of 
-n.wth   oth.r  parts  of  the  ortranisition.       In  ehan.'es 
'"  t  iis  nature,  then-  will   he  little  or  no   tendenrv  to 
"H..!ity  the  on-inal  pattern,  or  totransi,ose  parts     'The 
"01,..,  Ota  lirnl.  mi^rht  he  shortened  ami  wideiM-d  to  any 
•'xt.-it,  ai,d  h.-.ome  -nidunlly  enveloped  in  tlnrk  mem'- 
r..i  e.  so  as  to  serve  as  a  fin  ;   ..r  a   uehhed    f„ot  mi-ht 
■  iv-'  all  Its  ho;ie<»,  or  eertain   hmies,    lenj^tleiu-d  to  anr 
.•\',.nt.and   ti,..   nu-mhrane  roiuuvtini:  them  inerea-ed 
;■'  .-.riv  extent,  so  as  t..  ,erve  as  a  w,,,^  :    vet  in  all  th,. 
-rr.r  amount  of  mo.l.ficai.,,,!  the:.-  will  he  n..  tendenrv 
'n    ilttr  th..  framework   of  hon.-.  ,,r  the    n  'ative  .-..n- 
ne.tion  of  the  several  part.«.      If  ue  suppose  that  the 
.v,...nt   pro^renit...,  the  arehetvi.e  as  it  mav   l.e  ....Ij.d 
"•    .'ill    nwunmals.    had    its    liroh-    eonstriirted    on     the 
-M^tiniT    irener-il    pattern,    tor    wl  itever    puriw.se  they 
--ved    wecanatonee  perreive   th..   plain    siir.nfiratiof, 
he  fiomolo-..us  eon-tru.tion  of  the  limh>  thr.uiL'hout 
:     wHi..,.  .i..„        >„  „,tj,  jjjg  rnouth.s  of  ifi.serts,  we 


ivp  nnlv  to  swppo-e  that  their  eom 


•  I  i-er   lip 


p,  Jnatu 


libit 


rn 


.and 


on  proL'enitor  had 


ivo  p»'.-H  fit  nin  iiili*',  'lic-e 


If 


^L^ 


np2 


ON    TFfK    ()Rl(;i\    OK   S|'K<'If:s 


.  .   )  In   'l..MiouM,„^or,nultipIi,ati,K.  of  otlu-rx 

:'i,.';:;",T;,',ir,'-"' '"-"  "■  '••'-  '■'-■■  "->  >•■•.-; 

^  _        «r.  ..tioii.        \V  hy  sIk.iJ.J  t)ie  l.rai,,    1^  ^....1..... 

onii,";^'V'"'"'r''  ''''"''''   """"•'•■""*   and   ^nrh'^x^r^ 


MORI'HOUKJV 


3y3 


the  iH^riP'it  .ierived  horn  the  yielding   (.f  the  He.«rat« 
mm's    iti    the    art    of   iMrturitidij    of    maniinals'    "I'l 
hy   no    m.'arn  »'v|.l;iiii    tlie    s;iine    fonKtr(icti(,i]    in    tht. 
-kull^  of  f.inls       W  hv  should  Huiiilar  hoiien  have   !«.,., , 
:      .■roat,-<i   in  the  formation  of  the  ■.viiijr  and  h-y  of  a  t>  it 
M.fd   a<   th«v   are  for  Mich   totally  difforPtit   purposes  ^ 
VVhv   -tioiihl  one  crusta.ean.  whicli    han  an  .•xtrerocir 
omph-x    mouth    rornif<!   of  inanv   j^irts.   .■on-v-pa-ntly 
alw.iv,  havef..vvpr  let's  ;  or  cronvers,!  v,  iho^ewith  many 
Ifrs  have  simpler  mouth^  ?     Why  Mhc.uld  the  m-i«1h 
r..'Mls     stamens,   and  pistils   in   any  individnal   fiov*er' 
.hunu'h  ntrpd  tor  such  widely  different  purpc.ses  he  all 
i-onxtrinted  on  the  ti«me  uittern  r 

<  >n  the    heoryof  natural  sele<-tion, wo  ran  nati-fa.  'orily 
answer  the^e  questiouH.    In  tlie  vertehrata,  we  nee  a  seneH 
of  internal  vertebrw  hearintr  ceruin  pro.e>ses  and  appen- 
datres  ;  in  the  arti.-ulata.  we  see  the  hody  divided  mto  a 
•eriei  of  segments,  hearni^  external  appe'nd.i^es  .  and  in 
flowennt:   plants,   we  see  a  series  of  sucress.ve  spiral 
whorls  of  leaver.      An  indefinite  rej>etition  of  the  same 
part  or  ortran   is   the  common   characteristic  (an  Owen 
hasohserved)ofall  low  or  littJtvmodified  forms;  there- 
fore  we  may  readily  helievethat  the  unknown  proireuitor 
of  the  vertehrat-1  {M)s.sessed  many  vertehr*  ;  the  unknown 
pn.L'enitor  of  the  artieulata,  many  .eifment^  ;  and   the 
iink.iown    pn.ireuitor  of  fiowerintr  plants,  many   spiral 
whorls  of  h^ves.    We  liave  formerly  seen  that  parr.s  maay 
times  repeated  are  eminently  liahle  to  vary  in   n.iml^r 
am)  structure;  consequenUy  it  is  <juite  prol«hle  that 
natural    selection,   Hunnsf  a  lonK-<-ontinue<l  course  of 
iiiodifi.-ation,  should  have  seize<l  on  a  .erUin  oumherof 
tt.e  primordially  similar  elements,  many  times  rer)eated 
and  have  a.iapted   tliem  to  the  m<.st  diverse  puriKws' 
And  F..  the  whole  amount  of  mcMliriratiou  nil!  hav.-  U-en 
.'tfe,;te<l    by  slijfht  successive  steps,  we  need  not  wonder 
at  discovering  ,n  su.-h  j«irt«  or  ortrans.  a  certain  dcKree 
of   fundamental   resemhian.e.    retained    hy    the   str..nir 
(iiiiuipie  i»r  inheritance. 

In  the  Kreat  .lass  of  molluscs,  though  we  can  homo- 
n>iii^  the  part8  of  one  specie.,  w.th  those  of  other  and 


« 


:vj  i 


«>N    THK    OKK.IN    OF    ^F'KCIES 


lo^.os,  tl.at  ,s.  wr.  rxre  soldcm  er.ahled  to  sav  that 
I-art  or  or,.u,  is  l.on.„|,,,on.  w.th  another  in\he 
•"'J;;"'"al-  Am.I  ..ve  can  un.i..rst.ui.i  thi.  Lt  f 
rnollusrs  even  in  tie  lou-est  memherH  of  tl  e  -las 
do  not  Uud  nearly  so  much  indortn.te  repe  i  'on  ,? 
one  part.  a.  «e  tin.I  in  the  other  .^reat'cl  ul  e  f 
animal  and  veiretAhle  Irinjrdo,,,. 

Nat., ralis.»  ,re,,ientl.v  .peak  of  the  skull  an  torme 
mef.morpho>e.l  vertehra- ;  the  jaw,  of  orah.  J    ' 
morphose,     le«^s     the  stamens  and  pisti W  H^we 
.  etam.rphosed  le^ives  ;  hut  it  would  m  tnese  canet,  n, 
ablybemorecorrert.  as  Pn.fes.sor  Huxley  has  rerTJ 
to  speak,  hoth  .^ull  and  vertehr.,  Zl  'Z^Zl 

o  he"  r    '7  '•'"'  ^^^"  '"*'^'''"^"T>hosed,  not  one  , 
otfie.,  hut  from  Home  common  element      \a> 

f'euse.   tiM.yare  far  fr.m.  meanin^^  that  durinir  a  U 
<^ourse  ot  descent,  prin.ordial  organs  of  any  k  nd  -  ve 
^r*  .n  the  one  case  and  l.^m  in  the  other- ha  eartu 
-en    mod.hed  into  skulls  or  jaws.      Vet    'o  'trou^ 
the  ai.pearance  of  a  n.o.ii.icatinn  of  thi.  nat"  reZ' 

rrr'^'')!^'''  "•■^t.-l'-'-'J-t^  -•»"  l-rdly  avoid  emVo; 
Im^u:^^  havM.^r  ,hi„  plain  si^rnrtcat.on,  ( )n  ,n  v 
hese  terms  may  be  used  literally  ;  and  the  won^ieV 
-ut  of  the  jaws,  f„r  instance,  of  a  crab  ret..mi 
.Hun-roas  characters,  which  the  •  would  prohably 
rctanHMl  through  .nheritance,  if  they  had  real l"  be 
.eLamorphosed    during     a    lon^    co.rse    of    .  esce 


''■"m    trill 
explained. 


U 


■i^s,   or    from    some   simpie   apf^ndaife, 


fi,,.*        '/       •  -iirc.Kly  t„.,.ji   casiia    V  remarki 

Jl:,„-K  "'■?"'' ,»'■"'■  '"'■■lilfiTem  |,„-,„,« 

>..COt,(.i  ,.   "■■t'li..,.r.br,v     .f,on,„.,rt<.l.r..>P.i„imj 


KMFmVoUXJY 

t.e  cannot  now  tell  whether  it  be  that  of 
Mnl    or  rei.tile.      H.e  vermiform  hrv^  n 
iKH-tles,  etc.,  rewrmf.l..  Pach  other  much 
'•lan  do  the  mature  insects;  h 


.TOC 


a  mTmrriai, 


flp  of  mothH,  Hien, 
more  closeJv 


;  but  in  the  case  of  larva-' 


,  1   , 1  ,         —  '    '->-  •••   ••«'»-  \nifv  or  ia 


'-•»     Imh'.  of  life.      A  trace  of  the  law  of 


f(, 


,  ,  "■   ••■^-      '»  "•*<«■  or  tne  law  of  »'rMbrvoni.' 

Srdl  nf";;"'  ^""'^^'"^''«  J'-*^^  till  a  rather  late a^e   \h 
f-  rds  of  the  same  KonuH,  and  of  closely  allied%enera 
'■•on   re.enJ.!e  each   other   in   their   /r.t  and  ^^^ 
I   um.u..;    as   we   see   in    the   spotted    feathers   Z       I 
thrush  ^ronp.      1„  the  cat  tribe,  most  of  the  .ped^  a  ^ 
>^  r  „e<i  ..r  .potted  in  line«  ;  a;.d  ^tr.pes  can  lie  V>^in  v 
li.twj^m.hed  m  the  uhelp  of  tho  lion.      Ue  J.Z  . 
}  thou^rb  rarely  see  something  of  thin  kind  in  pUnts- 
b..  the  embryonic  leave.M  of  the  ulev  or  fnr/e  and    b« 
T'   Tr:  "^*''*'  P>'yllo<lineouH  acace;us,  a  «";;„"'!  J ^^ 
.i.v.ded  hke  the  ordinary  leave-  of  the  i;..nm!n  ,:,. 
,,.u'r  ^'IT""  '"  structure,   in  whi.h  the  em.,rw.t  of 
Hi  Wy   different  animals   of  the   s.ame   da.,   r.'imb le 
•"•f.  '.I.e..  often  hav.  no  direct  relation  to  the  r  con  d 
-n,,  of  existence.      We  cannot,  for  inst;ui  e   lurrt" 
t»:at  in  the  embryos  of  the  verteb'rata  the  piculi;    1^  f 

:.4ted":r  i  ?^"^^r"  "^^^^^^^  '-anS  "u  ':c 

[vh'^h  ,s      ^•""'•"J'0'"l'V'^n«.     i"  the  voun,.  mammal 

'of       TT^T^  v"   '''*•  ""'"^  «^  't«-  mother,  in  the 

;,  a     .  of  a  fro.  under  water.      We  he  no  more  re.-us  ,! 

.'t    be  same  bone,  in  the  hand  of  a  man,  win^  J! 

H  an>   Use  to  tb.^e  a.-nnals,  or  are  relafed    n.  fh 

'"■  '  -t.on.  to  «bich  thev  arc  expL.d  '^    ^"  '^"' 

he  o:..e   however,  i.s  different  when  an  mima]  durnu 

^  I'-Tt  of  Its  embr>-onic  career  is  a.ti;e    and  bis    n 

■  •  V'l-  f'T  .tself.     -n.e  period  of  activitv  ^'vl.ll'."  A" 

•Hnivi;:"  "1^  '",  ^'"^  '  '■"*  ''^'^'■'ever  it'c^es";;n;th; 
^'•<  •  and  a.s  be,-.nt,tul  a«  in  the  «d.]?  ..ui:aal     '  »  nm 


^'■*>-  OS    IHK    OIIKIIN    OK   SI'K(  IKS 


.".ijih  -'.o,  ,;tl  adapUitKirix.  the  Kimilantv  of  tli.«  l;irvi«.  or 
H.uv.-  .-.ihryo-  <,<  .,lli,..|  .init.i;iU  ij,  M.tn.-t irfi^H  mwti 
<".s,  un<l  :  an.l  .ax-,  .oul.i  Jh-  ynveii  of  tlw  l.irv^  of  Uo 
-|..-<i....  or  of  two  ^rr,)i,[,-  „t  «|.r,-i.>-»,  .iirferiiitr  .jiiite  ;v, 
nuirii.r.rpv..M  FMor*.,  from  ea.  1.  of 'it-r 'i.,-.!!  .lo  th.-ir  i.iult 
|.arfnt-.  Jti  mo-t  .Mses,  hovviurr,  the  iarvH^,  tl.otitrb 
u-tivf,  ■,till  (.l,».y,  more  or  lesM  ,  loselv,  the  law  of  com- 
rnoti  .-.o'l..  .u!i:.  reHiMi.M.iiue.  (  irrificMlp^  afford  a  gnn,] 
iMstan.-,.  of  flu.  :  evt;ii  the  ilI.iMlrioim  (  uvierdid  ,H.t  nr 
••eivetliHla  harnacl.'  w.w,  rt«  it  .•ort^iiulv  is,  arn.^areaii  ; 
hiit  a  irl.iii. .'  at  :ii,-  larva  >hows  tlii.-^  to  h«.  tlio  ra^e  in  au 
ntiiin-t.-ikahlo  manner.  So  a^ain  tho  two  uia.u  divi- 
■^lons  ,,f  .  irri|....ie<,  the  pedtinnilafcd  and  HesMJp,  which 
Infer  wid.-lv  in  e:;!.>nia!  ai.|>e.-iratice,  have  larv*  in  all 
their  sUijr*'^  h.arel)  di^tinLnnrihahle. 

Ilie  eiiii.rya  m   the  coiir>e  of  di-vflopinent  »renerallv 
rise-  in  oruaiiisation:   I   u>.o  this  expression,  thon-^i,  'l 
im   ,iwar..   ttiat  it   in   hanlly  j.ossihle   to  define  .hvtrlv 
Hhat   IS    nuMiit    hy    the   orirauisation    »>einjj   hijfher   or 
lower,      lint   no   one    pruhablv    uiil    dispute    that    the 
"lirtoriiy  is  higher  than  the  caterpiliar.     In  norne  cxses, 
H.^^tver,  the  mature  animal  is  jfenerallv  ronsi.iered  .-J 
iou..r  in  the  s.-ale  than  the  larva,  as  wiiJi  .ertiiin   para- 
Hitic  crusts,  eans.      To  refer  once  .itfam  to  cirripe«les 
the  larv*  m   the  first  Nfi^e  have  three  pair^  of  ](nr^,  a 
very  Hnipie  single  eye,  and   a   proho-scilorni.-d   mouth, 
With  whuh  thoy  fee.1  lartfely,  for  they  increase  much  in 
rtize.      Jn   ilie  second  Bta^re,  answering  tx>  t)ie  olirv^iJis 
statro  of    l.uttertiies,  they  ha^e  six  pairs  of  U'autifullv 
.•oii-tr...  ted   nafifury  lejr*.  a  p^iir  of  matfiiitioent  com'- 
p'Huid  eyH.s,and  extremely  complex  anteunH«  ;  hut  they 
■i.iw    i  <l.)>ed  and   imperieot  imuilh,  and   cannot  feed  • 
their  tun.  tion  at  this  ^ta^fe  i.s,  to  searoli   hv  their  well- 
dev elope, i  oPirans  of  -^ense,  and  to  reach  hv  their  active 
{Km-^^rs  ot   swimminjr,  a   pr<>{.er  pla<e  on  which   to   I>e-. 
coni,.  attu  he.i  and  to  undergo  their  final  metamorphosis. 
n  iieii  this  IS  completed  they  are  fixeii  tor  life:  their  lejo* 
are  i,oH  converted   into  prehensile  ortrans  ;  they  atrain 
oi.Uu   ..    weii-consiructtHJ    moutti  ;    but  they  have   no 
.in'ieui.«.j  and  iheir  two  eyes  aro  now  rocuuverted  into  a 


^■.' 


KMBRYOLCHJY 


Wl 


■  iiriutp.Hirisrlp,an<l  vcr\-  *!mplpey»»-s[><»t.    In  this  la-it  jiiul 

ompU'tt^  staU»,  cirri [H»«le'«  mav  l»e  40tisi(U«n*<i   a«  ••itlit*r 

iiore  hi^-^hlyor  more  lowly  orirniii-^ni  th.in  the\-  wt-re  in 

he    l.-irv;«l   roriditioii        Hut  iii    sonu"   trt'iiprji  the   larvae 

'»•(  otiie  <level()|>«»<l  either   into   lie-maphnMiiteH   having 

■fi«'  ordinary  stniiture,  or  into  wh.il  I  h;i\«  cailfii  corn- 

.••nu'iital   n>alt>s  :  and    in    the   latft-r,  'he  develMpinrrit 

JM-i  a<^iiredly  Keen   retroirrmie  ;   for  the  male  i»  a  mere 

-,nk',  wliich    !i\e«   tor  a   •«hitrt   time,  and  i-  de^tituU'  of 

iiioiith,  stomach,  or  ollu-r  ori,'an  of  imjxirtiin.e,  exrept- 

niiz  tor  reproducti'Mi. 

^^  e  are  r«o  minh  aiTimtomed  to  <.•'«  difTcreiu  i--  in 
striKtiire  hetween  the  eitihryo  and  the  adult,  and  like- 
wi-P  a  rhce  similarity  in  the  emhrvos  of  widelv  different 
aiimial«  within  the  same  class,  that  we  mitrht  Ih'  led 
to  l(n>k  at  the>«  fart-s  r.s  nece-sarilv  contini:ent  in  some 
manner  on  irroivth.  lint  there  is  no  ohs  loiis  reason  whv, 
for  instaiire,  the  winir  of  a  hat,  or  the  tin  of  a  porpoise, 
should  not  have  heen  tiketched  out  with  all  the  |»art.s 
in  proi)er  proportion,  an  s(.on  a^  any  structure  l>ecanie 
visihlo  in  the  er.ihryo.  And  in  «onie  whole  irroupn  of 
animals  and  in  certain  niem}»er«  of  other  croups,  the 
emhryo  doe«<  not  at  any  f>eriod  differ  widely  from  the 
adult  :  thuH  ( )wen  lias  remarked  in  retrard  to  cuttie-fi>h, 
'  tliere  is  no  metamorphosis  ;  the  cephalopodic  character 
i.s  manifested  lonjr  hefore  the  {>artn  of  the  emhrvo  are 
comfdeted;'  and  ajrain  in  spiders,  'there  is  nothirijf 
worthy  to  \ye  called  a  metamoq)hosis.'  The  larv»e  of 
inse<'ts,  whether  ad  ipted  to  the  most  diver-e  and  active 
hahits,  or  (juite  inactive,  heint:  fed  t.y  their  pirents  or 
pl.M-ed  in  the  midst  of  proper  nutriment,  yet  nearly  all 
iKiss  through  a  similar  worm-like  staiie  of  development ; 
hut  in  some  few  cases,  as  in  that  of  A  [this,  if  we  l.xik  to 
the  admirahle  drawinirs  hy  l'rofe>M)r  Hu*iev  of  the 
de^elofiment  of  this  insect,  we  «.ee  no  trace  of  the 
vermiform  statre. 

How,   then,    can   we   explain    the-e   several    facts   in 

~' t'-!--et,  —  ;i3i!!ci;      -.i.c    -.  c:  V     ;;  t-:;t-:  .1;,     ti-.it     :;;  :     lilii- 

versal  difference  in  structure  f>etvveen   the  emlirvo  and 
tlie  a<lult;     of  partrt  in   the  same   mdividual   eintiryo, 


.:98 


ON    IHE   OKIlJIV   OF   SI»E(  IKS 


-  *  -■ 


[i.i  ■ 


which  ultinifitely  bec-orno  very  unlike  and  servo  fo 
(luer-e  purposes,  heiritr  at  thin  early  peri(Ml  of  Krowtl 
.ihke  ;  — of  emhryos  of  ditfereiit  kjwtu^h  witliiii  the  sam 
<l;iss,  ^a-iKTiily,  hut  not  uuiversaliy,  rehemi.iiiitf  eacl 
"Iher  ;  ^  ui  l)ii»  xtructuro  of  the  enihryo  not  heinif  cloMeli 
K'l.ited  to  Its  i-oiiditioiiH  of  exiKteiic'e,  except  nhon  th( 
•■rnl.ryo  hcconie-*  nt  aiiv  period  of  lite  active  and  has  t< 
provide  for  it.-eif  .  of  the  emhrvo  apixarently  haviut 
Hon.etinieM  a  hijfher  ortranisatic.n  than  the'  rnatiin 
■iiiitnal,  uir.,  «-}iich  it  is  developed  '  I  helieve  that  a] 
tiiese  ficts  c.in  he  e^pl.ime.i.  as  follows,  on  iho  view  o 
dt'-ccnt  with  moditualiou. 

It  is  commonly  assnin.-rl,  perhaps  from  mon^trosilie- 
often    atfectinj,'   the  embryos   at    a   very   early    peruMi, 
thai  slitrlit  variaLi(»ns  ne'-essari! v  ap|»ear  at  an   p<jiittll'. 
early  period.      Mut  we  have  little  evidence  on  tliis  liead 
indeed  th.-  evidence  rather  points  the  other  way;  for 
It  ii>  not.),  ious  tliat  breeders  of  cattle,  horses,  and  various 
tancy  ammals,  ciiiniot  po-itively  tell,  until  some  time 
after  the  animai  lias  been  born,  what  its  meritH  or  form 
will   ultimately  turn  out      We  see  this  plainly  in  our 
own  children  ;  we  rannot  always  tell  whether  tlie  child 
will    be  uU  or  short,  or  what'its  precise  features  will 
he.      The  question  is  not,  at  what  period  of  life  any 
variation  has  been  wiused,  but  at  wh  it  period  it  is  fully 
dw[)lay.'d.      The  cause  may  have  acte<l,  and   I    believe 
jfenerally  ha.s  acted,  even  before  the  embryo  is  formed; 
and  the  variati<,n  may  l»e  due  to  the  male  and   female 
sexual  eiemeuts  havint,'  l)een  afTected   by  the  conditions 
to  wluch  either  j.areut,  or  their  ancestors,  have  been 
ex|)osod.      Nevertheless  an  effect  thus  caused  at  a  very 
early  period,  even  before  the  formation  of  the  embry*., 
may  ap|>ear  late  in  life;  as  when  an  hereditary  ilisea'se' 
whicli   apnairs  in  old  ajje  alone,  has  \>ecn  communi- 
cated to  the  offsprinjr  from  the  reproductive  element  of 
one  parent.      ( )r  atrain,  as  when  the  horns  of  cross-bred 
cattle  have  been  aflected   by  the  shape  of  the  horns  of 
either  parent     For  the  welfare  of  a  very  youuir  animal. 
:is  lonj;  a.s  if   remains  in   its  mother's  womb,  or  in  the 
Btf>f,  or  as  long  as  it  Ls  nourished  and   protected   by  its 


EMBKYOLCXiY 


31>9 


parent,  it  muHt  \te  unite  unimportant  whetlmr  m()»t  of 
iL«  charat  ti»r«  are  fully  actjuircd  a  littlt?  earlier  or  later 
HI  life.  it  would  not  Hijfnify,  for  in^itance,  to  a  Itird 
wiiich  obtained  its  food  best  by  having  a  lonjf  Wak, 
wiietlier  or  nut  it  asf^umed  a  beak  of  tliis  particular 
leii^tli,  as  loii;r  as  it  v,:m  fed  by  its  |iarent>.  Hence, 
I  ronelude,  that  it  is  quite  |>08.siblo  tliat  earh  of  the 
many  Buccessne  modirteations,  by  which  tvich  §pecien 
has  acfjuired  its  jiresent  structure,  may  have  -^uiier- 
-  eiieii  at  a  not  very  early  period  of  life  ;  ami  some 
■  iirett  evidence  from  our  domestic  animals  Kupport.s 
thi-.  view.  liul  in  other  rases  it  is  rjuite  possible  tliat 
ca(  li  successive  modification,  or  most  of  them,  may 
i.avo  appeared  at  an  extremely  early  i»erind. 

I  have  sLate«l  in  the  tint  chapter,  that  there  is  soinc 
evidence  to  render  it  prohalile.  tliat  at  whatever  .-ure 
any  variation  first  appears  in  the  parent,  it  tends  to 
re.ippear  at  a  correspon<lin^  a^e  in  the  otf^prinif. 
(  erLain  \ariations  can  only  appear  at  i-orrespoM<lin:f 
aL'es,  for  insUince,  peculiarities  in  the  caterpillar, 
locoon,  or  ima^o  states  of  the  silk-motli  ;  or,  ajfain. 
in  the  horns  of  almost  full-grown  cattle.  Hut  further 
t'laii  this,  variations  which,  for  all  that  we  can  see, 
•iiitrht  have  appeared  earlier  or  later  ii  life,  tend  to 
U'pear  at  a  corresponding;  a;re  in  the  offspriiii:  and 
parent,  i  am  far  from  meaniriff  that  this  is  invariably 
the  case  ;  and  I  could  g-ive  a  good  many  cases  of  varia- 
tions (tikinsf  the  word  in  the  largest  seiise)  which  have 
sujKjrvened  at  an  earlier  ,i/e  in  the  child  than  \n  the 
parent. 

liiese  two  principles,  if  their  truth  be  admitted,  will, 
I  believe,  explain  all  the  above  specifieil  le.adiiiir  fact- 
in  embryoloyy.  Hut  first  let  us  look  at  a  few  analoirous 
cases  iu  domestic  varieties.  Some  autln.  •  wlio  have 
written  on  Dogs,  maintain  fh:it  the  greyhounci  and 
Hill-dog.  though  ajipearing  so  different',  are  really 
varieties  most  closely  allied,  and  have  probably  de- 
scended from  the  same  wjbj  stock:  hence  I  was  euri.'i'jd 
'o  see  how  far  their  puppies  differed  from  each  ..ther  : 
1   >*a*  told    by  liree^ler-   that  thev  differed   iusi  as  much 


400 


ON     IHK    ()KI(;iN    OK    Sl'K(|KS 


n  tlii»ir  {».in-jit>,  ;unl  tliix.  juilu^iiiL'  I'v  tli**  ♦*>•»•,  ».«'»-mcd 
iklniosl  t<>  Ik*  thv  caM- ;  hut  nn  fwtii.illv  riK'a-iiriiitf  the 
old  cli)i;<)  and  th<>ir  six-davH  olii  |iiip|i:«*'',  I  fiuiiid  that 
ihf  {»u|>pn'«i  had  not  iirarly  ar(jiiire<i  thtir  full  aiiuMiiit 
of  j»ro[.Mrtiniial  dirteri'iicc  So,  afaifi.  I  was  tidd  that 
th»>  foals  <»f  cart  aiid  ra^»»-h<>^^«1J  diri»ffil  a*  i>iij<  li  ;w 
tin'  liill-irrow  II  animals  ;  at)d  thi>*  Hurpn-fd  rii»*  trrfatlv, 
a»  I  think  it  pmhaMe  that  thf  ditftTt'iK-*'  ht-'wei-ii  tln*^^« 
\\<t  hnM'dn  has  l>e«Mi  wholly  <aiiM»d  hv  s«d«»«ti<iri  wndrr 
doiiK'vtirarion  ;  hut  haviii-r  had  larefiil  iii»M-iir»Mii»'iit.'< 
rnaitM  of  ?h«  darn  atid  ot  a  thrp»»-da\-  old  <<dt  of  a  raie 
and  h«vivy  rart-hor>-p,  I  find  that  t!i«'  ciiits  hav«»  hy  no 
Tii<;tii«  a<"«|uirt'd  their  lull  aiiuiunt  of  }iroj>ortiona! 
ditfcri'iic**. 

A^  the  e\  idcritf  appears  to  nie  (•otirlii>i\  ♦•,  thai  the 
scv«>ral  doint'stic-  lir»'«vis  ot  l'ic»*on  have  di'Mienilcd  from 
on»'  wild  >p»'<i»«s,  I  roinpart'd  yoiiri;;  pitfcons  of  vanoun 
hre«-.l>.  within  fw»dve  hoiir-  after  U'intr  hatrhed  ;  1 
rarffnlly  rntM^ured  the  proportion*  (hut  will  not  here 
tfue  details)  of  the  heak,  width  of  ^lOllth,  len^/th  of 
no-,tril  and  of  eyelid,  si/e  of  feet  and  lenfrth  of  le^',  in 
the  wild  stoek,  in  p<iuters.  fantails,  runts,  harhs, 
dratrons,  earners,  atnl  tuinhlers.  N(tw  some  of  ihe^e 
hird«,  when  mature,  dirfer  so  extraonlinarilv  in  len;rth 
ami  torn)  of  h«'ak.  that  they  would,  i  cannot  douht,  l>e 
ranked  in  di>tinct  tjenera,  had  they  Ihh'ii  natural  pro- 
iluctions.  Hut  wlu'ii  the  nestlirnf  hirds  of  the-^e  -.exeral 
hrt-eds  were  placed  in  a  row,  thouji^h  rno>t  of  them  could 
he  ilistiiitfui-hed  from  each  other,  yet  their  proporti«)nal 
difference-  in  the  ahove  speciiie<i  -ever.il  noint.s  were 
incoinpara'dv  less  than  in  the  tull-tTown  turds.  Soiiie 
characteristic  points  of  difference  for  insUiiice,  that  of 
the  width  of  mouth- could  hardly  he  ijetecfed  in  the 
yiMiiiir.  liut  there  was  one  remarkalde  exception  to  this 
fi.ic,  for  t'le  youii4r  of  tlie  short-faced  tuinhler  differed 
fri'iii  the  yountr  of  the  wild  rock-tiiireon  and  of  tlie  other 
hi»'»'(t-,  in  all  its  proportions,  alnio-t  exactly  ;id  much 
a>  in  the  adult  -tate 

j'l,^  UM.  princ'ples  ahove  g-iven  *e«-iu  to  me  to  e\|)l  lin 
their.*-  lact.s  ni  reirard   to  the   later  emhryoiiic  stat;t^s  o/ 


WW'^m 


KMHKVOlXHiY 


401 


tlllH 


(lur  <i<imp?»tn'   vHriptifH.      h 


aruirrH  «u'l»Mt    tin 


iionrlv 


>*.'>•,  arwl    |M:r»'<»iH,  tor  hr.ediriif,  «li».ii   tliey  iiri> 
•  wn    up;    liifv   arp    imlrfcn'tit    «liotlipr   tJ.H  <l«'%irtHl 

HT  or 
iHrn. 
IP     lM.s«'S    JU^t     iriv«'ti,     inoH"     «'«I>«-<i;illy     tint      of 
"Mils,    n»>i'iti    to    Hho:*     tha*    Ji 


•  ji  •liitio-  .itid   strm  turn^   h;t\p   U'rii  a<-.|iiire«l   •sirl  . 
itiT  wi   liff,  if  tlip  full-irniwii   iiiiinKil    |.o>,M*;s«'-   tl 


\i>(\    tl 


e   iliarartpr'ilir    (lut»T 


H  .•-  whirii  trivp  v.iliip    to  Hjicli    br»'<Nl,  ami  *ln.  li  h 


•"•"ii  arciirnul.ittMl    l)\   mat 


I  H  "eUM-tiiiii,  have   riot 


K-eii 


first  apiipared   at   an   early  (K-rifwl  of   life,  ainl  1 
ui(nTit»'(i  liy  the  f>tf-i[>riiitr   at    a  corrpvj.on,) 


iVP 

.'••lUT- 


fia>  f 
'11'  not 


irly  ptTuxl.       Hut  the  ca-r  of  tlie  sliort-fac.'.i  tiuiil.U'r. 
tiicli  wlipri  twplve  hours  old    had   a<-.juirp.i   its   pmopr 


itrtioiH,  proves  tlirit   tliw  is  iif»t  tli.>  uiii 
t'rp  the  characteristic  ditferei 


versa!   rule 


i; 


icfs  intist  either  hav 


'[•eared  at  an  earlier  period  tliaii  usual,  or,  if   not 
e  differences   munt   have   been    inherited,   not  at  tl 


lavp 


so. 


wo 


r.irrespondinjf,  hut  at  an  earlier  a^e. 

Now    let    us   apply    thene    facta   and    the    ahove    t... 
i.'-incipleH      whiih  latter,  thoujrh   not  prove«l   true,  can 

-e  nhown  to  he  in  some  deifree  proliahle  -to  si»e«ie»t 
lu  a  sfitt  of  nature.  I^t  us  take  a  ifenuH  of  hirds, 
■i''s<etided  on  my  theory  from  some  one  parent -species, 
.iii'i  of  which  tlie  several  new  sp«v,PH  have  t»e<-onio 
MH.ditied  throuirh  natural  selection  in  accordance  with 
tficir  diverse  hahitw.  'Ihca,  irom  the  manv  sliirht  suc- 
cessive steps  of  variation  havinjf  supervened  at  a  rather 
'ate  Hire,  and  havuu;  J^en  inherited  at  a  correspoudinif 
tire,  the  youiiu'-  of  the  new  species  of  our  supposed 
L't-ius    mil    manifestly     tend    to    resemble    earh    other 

iiucli  more  closely  tlian  do  tli»>  adults,  just  as  we  },ave 
"•en  in  the  case  of  pitreons.  \\\.  „,ay  extend  tdis  vm-w 
•■'  vvhide  families  or  even  classes.  I'lit.  fore-lim».s,  tor 
iifstaiice,  whicJi  s.-rved  as  Icifs  in  the  {Kireii!-s|H.iiM, 
n  iv  tiave  be«-ome,  by  a  lonjf  course  of  moditication, 
•da|(ted  in  omi  diwendant  to  act  as  fiands,  in  another 
IS  pid<lles,  in  another  as  w'\u^  ;  .-.nd  on  the  above  two 
,i-Mi,i;.ies  —  nan.eiy  of  each  successive  modin.ation 
s  .{K'rveniufT  at  a  nther  late  ajje,  and  f)eint;  iiih.Tited 
«t    a   rorrpsjioridinir   late   ayt-     the    fore- limbs    m    the 


4»2 


ON     rilK    (»KM.IN    (»K    >I'K<  IK> 


eiiiLrv"-.'!  lli«-  -Dv.'r.il  <leHreii<l;iiiU  •)!  tli.-  |.;ir»'.if  hi.-,  i.-^ 
will  Hliil  ri'-ciniile  oach  <»lher  cIom-Iv,  t<>r  liu'v  a  ill  nn 
li.ivo  h.'.'ii  ni<Hliti«'(l.  Hut  ill  .'ii.  h  ot  uiir  n.w  ^|..vi«.v 
111.-  iMiii.ryoMu-  fort'  1 1  nil.-  "ill  -litior  irroallv  from  t)i. 
l.irf-litiilH  ill  tlH<  nvitur«'  innnal  ;  tlio  limlis  in  \h> 
litter  liaviii;.'  n luliTtfoiif  murli  ni«nl,ti<:iti()ii  Ht  a  ratlici 
l.it*"  i.«'riu,i  o(  lito,  anil  liaviiitf  lli""'  •'•'«'"  ••oinertp. 
II, f(.  lian.U.  or  i.a.j.lle^.  or  v^lnj:<  Uliati-vt-r  iiifiti 
eii,..  luiii.'  .oiitiM^Ml  ..uTriw.  oi  nsf  on  tlo'  ori»'  li.iti.i 
,uii.  .liSiiM-  on  llie  otli.T,  may  have  in  moriiiyinjf  ai 
or::iri,  su.li  influ.-n.  »•  will  maiiilv  aiioft  tin-  mattir. 
jiimnal.  ^\irKli  li.t-  .•oiin«  t4i  it^  tull  power-^  of  a.tivif 
:iii<l  lia>  \n  L'riMi  lU  own  livin*;  ;  an.i  'he  ori«v 's  thu 
nro(iii."l  will  Ko  inlxTitwl  it  a  .•..rr«'-|.on(lin^  niatim 
aifi'.  U  iicr.'.i-  thf  yoiHi^ruiil  rfma;ii  iinmo(iiti<-.l,  o 
Iw^   mo.iitii-.l   111   a   le!^>er  .Ir-rc.-,   l.y   the  etfert^   ot"  ur- 

an<l  di-u-^*'. 

In    i.Ttaiii    ..lacs    the    Hucri'ssive    steps   of    vanatioi 

miL'hl  siiiKTveiio,  from  causes  of  wlmh  we  are  wholl 

iuMi-.i-ant,  at   a  very  early  period  of  life,  or  each  ste 

miu'ht   li<-  inherited  at  an   earlier   period   tlian   that  a 

which   il   lir^t  appeared.      In  either  ca«.f  (km   with   th 

siiort-t.i.  cd  tunihl.'r)tlieyoiin;:<M  <-    '  -vovo;.;  i  closel 

rocnihl.'  the  mature  parent-form.      *>  e  have  ««eeu  th-i 

this  is  the  rule  of  devel.ipment  in  certain  whoie  jfrouj 

ol"  animals,  as  with  cutlle-li^-h  and   spiders,  and  with 

M'w  nicmtier^  of  the  ^reat  class  of  insecUs,  as  with  Apiii: 

With  ropcct    to  the  final  cuise  of  the  yountr  in  the.- 

ca.ses    not   UMder;:oiinr   an>    iiietainorpho>.i-,    or    .losel 

rc-eiuldiiiir   their   parents    from    their   earliest   .iire,   w 

can  >ee  that  this  would   result  from   the  two   lollowin 

continirencics:   firstlv,  from  the  yountc,  durin^r  a  coup 

,)f  niodiii.  atioii  carried  on  for  many  generations,  haviii 

to  jinnidc   for  their  own   wants  at   a  v»>ry  earlv   st;u 

,,f   devi-lopment,   and    secondly,    from    tiieir    follnwn 

cx.actly  the  same  hahitw  of  life  with  their  parent ,  ;  f< 

III  this  ciM',  it  would  he  indispensal.le  tor  the  cmsUmk 

of  the  >j.ccies,  tiiat  the  ciiiid   sikmiIu    i*e   ruMiilied  at 

verv  early  aire  in  the  s;une  manner  with  its  parents. 

accitrda.ue   with    their   similar    habit.>.       >onie    turtli 


■r''»H  ■:-«... 


KMHRVoI/Ki> 


*tt:i 


•III  tnaUoii,  bow.-v.T,  of  ho  fmltryo  not  uii<)«'r(f-Mii|{ 
•iriv  incUrnorpliOHii  in  pfThapx  requi.sitH.  Ij,  on  thi* 
ofli»T  hand,  it  protih.!  i},e  ynuiuf  to  fo'h.w  hahiw  ..i 
li'e  m  any  <l»vr»'»  ih:t>  n-iit  from  tho>ie  ol  thi'ir  |k-(riMit 
ami  constiijuenlly  to  ho  ronstructrd  in  a  ■.lijfhtlv  dif- 
;<'r»«Mt  manner,  then,  im  tiic  priiu-iplo  of  nl  rit.iiur  «• 
•  orre-(KiMd  ne  •'^rex,  the  a<tivi>  vonnj^  or  l.irvw  Tiiitriii 
M.'\]\  1k»  re'irirrctl  i,y  natural  •i<'li»(tii>ii  ditftTpnt  to  any 
'  iinccivfihU'  exU'n'  from  their  p.«rftitK  Sncli  (iiiier- 
••mes  ni .:.'hf,  aUn,  iK'.dme  r<»rrei.»t«'d  witli  HH<Texsi\f> 
■itatres  of  liiiM'it.pmrnt  ;  ho  th.it  tli«  !.-irva>,  in  the  tir'.i 
•<:.-iire,  nti^flit  diiffr  crt-atly  from  'liP  hirv»'  in  the  (i«>«'«>ii<i 
't,i::p,  an  we  ha\««  -e«'n  to  Ih>  tli«  rawe  witli  .irripfdi-.s. 
Hie  ailult  miL'ht  ht'Cdriie  fif!»'d  for  sit«'H  or  hahiti,  in 
wiiu  h  ortrans  <i*  hn  oinndon  or  of  th*-  •i«>i.s»'8,  wtc. ,  i»ould 
Ik3  usoIps-  ;  and  in  tliw  easy  llio  final  in»-iam«irph(»sH 
iMi'iid  lie  --.lid  to  lie  n!trotrra<h>. 

.\  •  all  the  ortranic  hcui;:-,  »'x*inrt  and  riri-nl,  v»(i:,  ,. 
iiave  ever  lived  <tn  this  earth  liave  tn  ItiTlansed  tojfether, 
i.id  as  al!  have  heen  couue«'ted  l>y  the  finest  4rr:i'iati<in>., 
■  lie  best, or  iudeed ,  if  our  collectioi'>  viere  nearlv  [>erl»Tt, 
'he  only  po««ih]e  arrainjement,  w:>uld  l>e  >rein',iiotfi''ai. 
I>t>sfont  heinp^  on  my  view  tlie  hidden  l)ond  of  mn 
nection  which  natura!i^f.s  liive  he-"  fekiitr  vjnde: 
the  term  of  the  natural  system.  <  )n  tlnn  view  *■ 
•an  understand  Inm  it  is  that,  m  tlie  eyes  of  miw 
ii;»fiirali-tM,  tlic  htructure  of  the  emhrvd  is  even  mure 
iriipMrtanf  for  classifiration  tlian  tliai  of  the  a^Jult.  Fn,- 
'ii»-  enihryo  is  tlie  animal  in  itH  letw  modified  Htate  ; 
liifi  in  KO  tar  it  reveal.,  the  Ktructi.re  of  itH  |)n)::»  tiiWir. 

II   two  t:iaups  of  animals,  liowever  much  tiiey  may  at 

[■r.>-.ent  d:if.'r  from  each  oth«'r  in  structure  and  haints,  i; 

hey  pas.s  ihroiu;}!  thes.imeor  similar  emhrvnic  stai,'■e.^, 

■vi-   may   tee!   a-.-'ired    th.it    they  liave    hnt'h   .Icicendcii 

"in  the  same  or  nearly  similar  narciiLs,  and  are  there- 
'"!e  in  that  decree  eli.».dy  relattul  Thus,  community  in 
eictiryonic  structure  re\  -als  cnmmunitv  of  descent  j- 
v»iil  revcai  this  community  ol  de.seenl.  imwever  mud' 
'Jie  struc'ure  of  the  adult  may  have  Ikhii  m<Miifi««<j  an.t 
■lii^cur^'i  ;   ■•*?  havp   -jeeii,  for  instarice,  that    '-irnpetie- 


I 


M 


vu 


ON     !llh    OKMrlN    OF   M'K("IK8 


ran  at  oiicp  )n-  rorniru\'*ed  \>y  their  larva*  as  hfilfnu-ing 
t(»  t]\(*  {irr»-:i»  rlass  rif  tTii>.t;ict'a:is.  A-*  X\io  riiiKrviiic 
ttatf  "If  t'ii>'h  sp^^fies  aiitl  (rroup  uf  •ipf'cies  pftrtiaUy  showH 
ijH  tl.t"  -triirture  ot  their  h'v«  moilit'u.'d  am  ieiit  protrPni- 
'.ir-,  MO  cui  clearlv  few  w  hy  aiu-icit  ainl  cxtirirt  forms 
I*  lift'  'ih'iiihl  r«"-('nihk>  f)ie  enihryo-  .>f  tlicir  '!»■- cnfl- 
4iit<.  ..i.r  pvi-tiiiif  sp«'cif>**.  Affassiz  ht'lif  \  <■■<  tlii!*  to 
*>♦>  a  l.ivv  of  nature;  Imt  I  am  hourifi  tr)  (•(int»'~r'  that  I 
iiiily  )n»('e  td  -t'c  th>>  law  h»'ror\f'ter  proved  true.  It  <  an 
ltepr<i\e<!  true  iij  lliii>e  ca-ies  ahme  ;;»  whicli  t.'ie -iiuierit 
«tate.  iH.-.^  supposed  to  he  represented  in  existii.tr  em- 
lirvi'S.  ii.iH  not  heen  ohliterated,  eitder  hv  tho  suci-e^sive 
vari.afioMs  in  a  hnitr  (viur^e  of  rnodittcation  havinir  j'ijht- 
vpned  at  ;i  v  erv  earlv  a;c<".  or  hv  the  variations  tiwintf 
>ieen  in!ier;!e<i  at  an  eariier  rteri^wl  than  that  a^  wtiieli 
:}ie\  Ur<\  appe.ired.  It  '-hould  al-o  t»e  horm*  in  niitid, 
thai  t}ie  «i'jipo->ed  I.t^  o(  resenihlance  of  aji'  ient  forn»>< 
o.''  life  to  tiie  enihrvonic  ^tatres  of  rerent.  forii:.-,  mav  he 
triM".  hut  yet,  owin'7  to  tlie  ;r«»oiotci''ai  re*  ord  not.  ;^x- 
tendMii;  tar  enowtrh  hark  m  time,  inayrrinain  tor;;  !oi>? 
y^eriod  .  or  for  e\er,  iii.-.ipahle  of  demonstration 

linis,  as  it  seerns  to  me.  tlie  leadiritr  tac't-^  in  emhryo- 
io^'v,  whi(  h  are  second  in  importJince  to  none  in  natural 
lii^itorv.  are  .explained  on  the  principle  of  slij^ht  r-icvdifi- 
c.ttions  not  appeariinr.  in  the  many  de-cendants  'rorii 
-oiiie  one  ainMent  ]iri>irenitnr.  at  a  ve'  early  period  in 
the  lite  of  eaeh.  fhoiiffh  perh.tp^  reused  at  tlie  earliest, 
'iiid  heiiiL'  inherited  at  a  eorrespondinc  not  early 
j)erio('..  Kfuhrvidoev  ri-es  greatly  in  interest,  w  hen  we 
thu.><  look  at  the  emhryo  a*-  a  pn-ture.  more  or  le.»s 
nii>('ured,<if  tlie  Common  parent  'rm  of  each  iireat  cla^- 
of  ;Hiiiii.i!s. 

h'lnh'Ut'nli.  n, .  ntrajihwrt ^  nr  'ifmrterl  '/r./i/TjA.  -  «  trtani 
or  ]iar's  in  tir-  •^trantre  condition.  he;irii  u'  the  -t-imp  of 
'nuulitv,  ar(-  ex'retuelv   coinnion    throu;i'liout    n.iture. 

the  m.iles  of  mainrnais  :     I    presiinis»   that  the  "  tn'^tard- 
wintr  "  in    hirdn   may  he  >valelv  cor  ;ed   as  a  iliifii    in 

•>  rudnneiiiiirv  siat»       in  mtv  uui  .akfts  oiiC  toKe  of 


lU  Dl.MKNlARV    ()R(;ANS 


•fli 


the  iMiijrs  is  rudimenuiry  ;  iu  ottit>r  siiakoM  there  art* 
riiii;'i!»'iits  of  th»-  jM'lvi«i  niiti  hind  lini^s.  Sunif  i»t  t:ie 
(■a.-^e--  i»r  riiiliiiHM'.Lirv  dry:.'.!!-*  art*  exlrcint'ly  ruriitut  ; 
for  iii^iantv,  the  jiroseiice  o'  tetith  in  Icftai  w!i.iif.«, 
wiiiih  w)i»«ii  jjTrtwii  uji  li;iv^  not  a  tooth  in  their  fuaiU  ; 
at'.ii  !h<'  ('roeu'-f  of  t«»tMh,  •♦inch  iitnor  out  thrnii4rti  'i'e 
turns,  in  the  iipjtfr  jaws  of  our  unhoru  ralve«..  It  ha.* 
oven  l-Hcn  sta'cd  on  ir'>o<l  authority  tiiat  riidiiiuMit^  ot 
tpt'tli  can  l>i«  <it'te<'fe<i  u\  tlie  iieaks  of' certain  emiiryonic 
ftird>.  Nothiiiir  can  he  plainer  than  that  winj^n  are 
foriiu'd  for  tli;:lit,  vet  in  how  many  insprt.s  i\i<  we  see 
wiuL'>  ''O  reduced  in  nhei  a?^  to  \n'  utti-rly  iiicapv.;.'  iti 
riiirht,  and  tint  rarely  lyiufj  under  w  mtr-oa.xe.-,  nn.ily 
sohi.-red  tOi.'ether  I 

i'fie  nieainntr  <f  rudimentary  oryans  is  of>en  .juite 
uiimi>tal'ahie  :  for  iii'tance  tliere  are  heetk-s  at  tiie 
•.aru»'  treiius  (and  c^en  of  tlie  same  Hpecie^)  resiMiihlin^r 
"acf!  i)ti;er  mo>t  closely  in  all  respects,  oneof  whirh  *iil 
'la^e  fiiii-!-:/id  wiriij.s,  and  another  mere  riidimei'Ls  or 
■nernlirane  ;  and  here  it  is  itiiposnilde  to  douht,  t'.it  the 
rudnnenLs  represeni  winifs.  lludinieniary  or^'ann  some- 
times retain  tlieir  potentiality,  and  an-  merely  not 
developed  :  thiw  seem>-  to  he  the  cane  witli  the  mamm.t- 
of  male  mammals,  for  many  instance^  are  on  rccdrd  ot 
t)ie-e  organs  having' hecome  well  uevelope*!  in  full  iirovvn 
males,  H.ml  having  secreted  milk.  >o  airaui  t;n'r.«  ;ire 
nurmally  four  develojted  and  two  rudimentary  teats  m 
the  uddiTs  of  the  K*Mnis  l»<m,  hut  in  our  diiine>iic  c<''*>i 
the  two  sometime**  U>come  devtdope*!  and  tfi-e  nnlk. 
In  plants  of  the  same  .species  the  peials  •.ometimes  occur 
as  mere  rudiments,  and  sometimes  ni  a  •♦jil-deveioped 
^tafe  in  plant.s  with  sep.irated  >exe>,  tiie  mile  tiovvcrs 
(dten  h.we  a  rudiment  of  a  pistil;  ami  Kdreuter  found 
that  t»v  cro-sing  su<'h  male  plant.s  witli  an  herrnajdiro- 
dite  sj„'(  i(>H,  the  rtjiimont  of  the  pislii  in  tli«'  hvltrid 
otf>.prMiir  wa.s  much  increased  in  f^i/.e  ;  and  ti^i-  »how« 
that  thf  rud  iiHMit    and  the  perfe«'t  pi-til  are  er>scnti..i:% 


i\ 


1 

\i  1  Kf  in  I 

.;i.u  1 1 

-tara-         i 

.\ii  org 

an 

«c 

vw 

iig 

for 

two 

pur 

>osej<. 

may 

(.e. 

•i>nie  ru- 

li 

g-ii 

in 

rr» 

■■.Liirv 

or 

u 

tte 

rlv 

at 

•ori( 

d    tor    on 

%   even 

the 

rpo 

re 

i)he 

of 

4i)t; 


ON    THK   ()R1(;JN    OK    Sl'KCJKS 


niiiortaiit   pur|M)>f  ;   and   roiiiain  perfettlv  efficient  for 

he  nlher.      Thus  in  plants,  the  office  of  the  pi^'til  \:i  U> 

illow  the  pollen-tuhes  to  n-ach  tlie  ov.iles  protecte-i  in 

IK'  '.■.arium  at  its  hase.      I'he  pistil  consists  of  a  '^tiirma 

•  iipiMrtcl  on   the  style;  hnt   m  some  CftiTiposit.e,  the 

iiale  llori'tH,  which  of  course  cannot  he  fecuiuiated,  liave 

:»  pistil,  v*lii,-h  is  ui  a  riniiinentary  state,   for  it  is  not 

crowi.e.l    witli   a  stigma  ,    hiit  tlie    style   remains    well 

'Jevel'ipcd.  and    is  rh.thed  witli  hairs  as  in  (»ther  (om- 

positB,  (oi  the  l>urp..st,  of  hru.shina- the  pollen  out  ofth.- 

■*urn)ii inline   anther.-.      Ajrain,   an    ort,'an   niav   hecoino 

riidimt'iitary  for  it.^   pmper   purpose,  and  l>e  used  for  a 

iistinct  ohi.-ct  :    in  certain  tish  the  swiin-hladder  seeir.s 

a    l)e    nearly   rudirin-ntarv   tor   its  proper   function  cf 

irisintf  huoyanrv.   hut    has    kn^oine    converted    into    . 

na.scent    Irealhni:;    orpau    or    luujf.       ( ►ther    similar 

iintanccH  could  ho  ffi\en. 

<  )riran9,  liowever  little  developed,  if  (it  u-e,  should  not 
lie  called  rudimentary  ;  they  cannot  proj^rlv  be  '^liil 
:o  he  in  an  atrophied  condition;  they  may  he  caile<l 
nascent,  and  may  in-rt-atter  he  de\.'hiped  to  any  extent 
hy  natural  selci-'  <u.  Kudiirienfiry  nrirans,  on  tiie  other 
fiand,  are  essentially  useh'-s,  as  tet  th  ivhich  never  cut 
'hroutrh  tlieirums;  in  a  still  less  developed  condition. 
they  v^ouhi  he  of  still  ].->s  use.  Ttiey  cannot,  therefore,' 
under  their  jiresent  condition,  ha\e  heeti  formed  bv 
natural  -election,  «!ii,h  acts  solely  by  the  preservation 
or  useful  modifications;  they  lia\e  iH'eti  retained,  as 
we  shall  see,  hy  inheritance,  and  relate  to  u  former 
■00(1)1.011  of  their  |.o>sess..r.  It  i<  difficult  to  know 
"hat  are  n;i.s<  eiit  organs  ;  l(M-k:ii^  to  the  future,  we 
•uinot  of  cour-e  teil  how  any  p..fl  will  be  dev.doped, 
and  whether  it  is  now  iia>cei  ;  ;  hHikinjr  to  tfie  past! 
creatures  with  an  iir;:an  m  a  tia.sceut  condition  will 
uenerally  have  been  supplanU"'  and  exterminated 
'ly  their  succe-ssors  with  the  organ  in  a  more  perfect 
Hid  .ieveloped  condition.  The  win;r  of  the  pentfum  is. 
i  iii^n  servue,  .»iid  acts  a>  a  iin  ;  it  may,  tiierefore, 
represent  the  na.scent  stite  of  thp  wiuirs  of  bi.-ds  ;  n..t 
that  1  helievt-  ttuH  to  trt*  :hf  .Ave,  it  is  more  jirobahly  u 


Rl DI.MKNTARY   (>R(;AN^< 


407 


eiiiictvl  o rtrau.  riHMlifuM)  tor  n  new  futirtion  ;  the  wintr 
.)f  the  Ajiteryx  is  useless,  and  is  truly  rntiunciitary. 
The  mammary  elain!'*  of  the  ( >niithorhyiithus  may, 
;erh.ips,  l»«>  (Muisiiiered,  in  romparisiin  vvitli  the  urifler 
of  a  «ovv,  as  in  a  ria-<ent  stAte  I  he  ov  !trer<ui«  freiia 
rif  certain  cirrij>e<les,  which  are  urily  sl;ir)itly  deveh)peii 
ami  wliich  have  cea-e<i  to  ffixe  attachment  to  tlie  ova. 
ire  nascent  hrandna  . 

Kuciimentary  orirans  in   the    individuals  of  tiie  san.-- 
-[MM'ies  are  very  liaMe  to  vary  in  deirree  (»f  development 
.ml   in  otlier   re^^pects.       Moreover,    in    closely    allied 
fl  pecies,   the  detfree  to  which  the  sinie  ortran  .  as  heen 

endered  rudimentary  occasionally  differs  nuicli.  This 
,itter  tact  is  well  exemplit'i-d  ui  ;l:e  state  ut  the  win;.''s 
ct  llie  female  motlis  in  certain  jjroups  Kiiiiin>entar\ 
■  Ttmus  niay  he  utterly  ahorted  ;  ami  this  imj.its,  that 
•'e  find  in  an  animal  i-.r  plant  no  trace  of  ari  oruan. 
ivhich  anaJoiry  woulil  Ic.kI  u^.  to  expect  to  find,  and 
winch  iM  occasionally  'oiind  in  monstrous  individual 
lit  the  species.  Thus  in  the  snapdrat'Dn  (antirrhinum j 
we  ireiier.'illy  do  not  find  a  rudiment  of  a  fifth  stamerj  ; 
i>ut  this  may  soini'times  lie  seen.  In  traciiii:  thi-  liomo- 
if»i:tes  of  the  same  [>art  ii  ditlt-rent  members  of  a  class, 
iiothini:  i"  more  common,  or  more  necesscr\  ,  than  the 
Use  and  discovery  of  rudiments,  i'hi.s  is  well  shf)wii  in 
the  drawin^is  triven  hy  ( )wen  ot  the  boues  ot  tlx'  lej;  of 
the  horse,  ox,  and  rhinoceros. 

It  is  an  import.mt  fact  that  rudimentary  oriraiis.sio  h 
I-  teeth  in  tiie  upper  iavvs  of  wiiales  and  ruminants, 
can  often  be  detected  in  the  emriryo,  hut  afterwards 
wiiolly  disajipear.  It  is  also,  I  lielieve,  a  universji! 
rule,  that  a  rudimentary  part  or  <ir:ran  is  of  jrreater 
-i/e  relati'cly  to  the  adjoiniriir  p.vrts  in  tlie  embryo, 
than  ill  the  adult  ;  so  that  the  (»ru';ui  at  tliis  early  a4?f 
■■•>  less  rudiineiit.iry,  or  even  cannot  in-  >;iid  to  i>e  in  uuv 
iie;rree  rutiimentary.  Hence,  also,  a  rudimentary  orifan 
;ii  the  adult  is  often  sa;d  t«>  have  retained  its  emi>ryonii 
coiiiiitir>n 

1  lia\e   now  given   tiie  leading  fact*   with   res-^tect  to 
rud!tiieritar\' (ircan.'i.     In  rt'fUi'tinjr  on  thi-m,  eve'"v  oMe 


408 


ON    THK   ORKJIN   OF   SI  r.> 


■ 

1 

i 

mu<t  >..■ -triirk  wr.h  -i-toni-iitn.'iit:   fr)r;tip  same  reason- 
in-    |M,w.T   whicli   t.'ll-.   u-    i.lainly  tii.il  n"-'t   }'irt>   u;d 
ortr:!;!-   ar..   0)i<|m-)t.'iv   fi.l.ipf.-.i    tor     .  titfiiii     (.uijkis*-!. 
t»>ri<  lis  \M'li  ••<|u:il  ]i!inn:.'ss  th;it  \\\>'.-f  rudinient.-irv  oi 
atr..i,li:.'.l  (uians,  are  imi-'-rfVot  ;in<l  ii-.-less.      in  w..rk» 
on   ii.itur.il   lustcirv  ru.liinfntary  ortraiis  are  L'»Mit'nill> 
■^.li.l  TO  li  re  ii«'<'n  'cr.-ritecl  "  N.r  tlie  sak.'  (it   synnm>!ry. 
,.r  ;ii  ordiT  "  t.>  c mi-h'to  t)iP  s.'licnu'  of    natiir.^  '  ;     i-u 
this  -.■fins  to  ni"  iK»  t'vpiaiiaT.ui,  riieroly  a  rt'-stat.>iii.Mi 
of  ili«'   tH«-t.         N\  o  lUI    11    l>»*   tlioiitrlit   M.tti.  i."!t    to   -a; 
tl   it    !.«'(a!i>t'   |.laiit'ts   r»'V(iUo   in  cUiv'k-  •'oursfs  roun- 
til.'   sun.  -atollites   mllnw    the  siine  .'ourse    roiiml   tt. 
plan.'t.s.  tor  the  sake  of  symmetry,  and  to  .•omplete  th 
Kcli--!i:.>  (if  naMirer       An  eiiiinpiit  physiol(.;:ist  a.-rouir 
fur   '.li»'   i-rr-.-ii.t'  of  riKiinu'titary  orLMiis.  I»y  Mijiposii- 
tha*  tht'v  s.Txe  to  exrrete  matter  in  excess,  or  miurun; 
to  the  svst.Mo  :   hut  can   we   supix.se    that   ti,e  niinut 
pap. :ia.  which  often  r.-|.re-ents  the  nistil  in  male  tlower- 
and  which  is  f(.riiie(i  nierelv  of  celluhir  ti-ue.  .an  th;i 
actr     (an  we  siij-po-e  that  the  formation  ot  rudimentar 
teeth.  '.Nhich  are  stihsei|uent  ly  atisoriied,  can   he  (it  an 
service  to  the  nipidlv   trrowinir  emhryonic   calf  hy  th 
excreii.ui.d  precious  pho-pliate  of  lime  .-   W  hen  a  man 
rinfirers  Itave   I.een  amputated  .  imperfect  nails  somctinu 
appear  on  tlie  stumps:    1  could  as  soon  heheve  that  tlie- 
ve-tit:es  of  nails  have  appeared,  not  from  unknown  !,i.' 
of  irrow^h.  hut  in  order  to  excrete  horny  matter,  as  th; 
the   rudimentary  nails   on  the  tin   of  the  manai.-e  -mm 
formed  for  this  purpose. 

On  my  view  of  descent  with  moditication,  the  oriiri 
of  riidiiiientarv  ortrans  is  simple.  We  ha\e  plenty 
ca.se-  of  nidmientarv  origans  in  our  domestic  produ 
tions.  ;is  tlie  stump  of  a  tail  in  tail!e-s  breeds,  tl 
vestijre  of  ill  ear  in  earle--  l>reeds.  the  reappearan^ 
of  minute  daiurliiur  lioriis  in  hornless  hre.'.ls  ot  catti 
more  e-peciallv.  .accordiiuf  to  \ Ouatt.  in  youni:  animal 
and  thestjite  of  the  wh<de  flower  in  the  cauliiiowc 
\\  i'  oiten  see  rudimenl.s  o!  van.tu-  jNirts  ;n  ::;!;::-;■.!•: 
Hut  1  (iouht  whether  any  of  tliese  .  ases  throw  lijfht  < 
the  oripn  of  rudimentary  or^-ans  in  a  state  of  nalur 


KJ  DIMENTARY    ORGANS 


4f>4 


furtlKT   than    I'V   ^^lMW•iIlL'   that   r'ulimPiits   i;i:i    (•«•  {iro- 
ilijiffi  ;   ti'T  I  doubt  wlu'llier  sfift  it'>  unii.-r   iiatiin"  t'\»'r 

the  main  airencv  ;    that  it  Ins  l»>«i  in  siicrt>*Ni\»>  ci'iicra 


tioii!- 
tht'v 


to  ti 


»'  t^railiial  rcwiuitHm  of   various  organs,  ui.ti 


ive  hfco'iit'  rinliinei;t«irv,-   .'«■*  in   iht*  iM»t>  n 


f  ;i 


p\»'>  ot  aniinalH    ; nliaoitiiic  « 


lark 


cavern 


and    of  tiif 


nt." 


of"  iiinls  inhaliitiiiiT  ocranif   i>land-.  wini'h   ha\«' 
lidta  t.oeii    iorr»>d    to  take  Hii:iit,  and  have  ultiiiiatfly 
-t  thp  [.ovuT  of  tlyitiir.    Atraiii,  an  orj: an  iis»«fiil 


uiiiirr 


tTt.iiii  conditiniiSjmitJrht  Ix'coriic  injurioiisiinderothfi". 
a-- V*  ii!i  ;!n- «  nitrs  (if  iKjft  .(•>  li\in:r"n  ^niall  arni  i'xpoM»d 
i»I:ii;<l-.  ;   athI     II   thi-*   ''a-t*  natural  fwlcrtinn  '^ouid  coii 
tmuf  viuHlv  to  r«'<iiii-e  the  urtfau,  until  it  was   rriid»'red 


ariiiiess  and  rudiniv-utarv 


\i 


lariirtJ    in    functitiii, 


liiirh   ran    he  etffc'ed  bv 


;n-L'ii<irily  Mnall  >l«*|»s,  is  wi'hin  the  power  of  natural 
-oil'. -t ion  ;  so  that  an  ortfan  rf-ndercd,  'ii.rnii.'  lii.nuftvi 
•  ia''!"-  of  life,  u-ele^!*  or  iniurious  for  one  purpoe, 
uiiiilr  he  nioilitictl  and  uvd  lor  anotner  purp<  ^e. 
'r  i:;  ortran  nii^ht  he  retained  for  one  alone  of  it,-* 
toriiifr  functions.  An  oriran,  when  ri-iidered  u^ejr  ^- 
mav  well  he  vanahle,  tor  it*  vanatiMus  lannot  in' 
che.  ked  bv  fiatural  sele'tutn  At  «liatever  perani  of 
lite  d:>use  or  <elei:tion  reduce-,  an  ori:an.  and  this  will 
iit'iierallv  Ik*  «}ien  the  lieiuir  ha>  corne  to  niaturitv  an'l 
to  it*  full  powers  of  aftion,  liie  prinripie  of  iiihei.'an<e 


•it  (  orrespondintr  aires 


will 


reoroiliu'e 


tl 


e   ort^an  ui 


dmed   gtiite  at  the  same  aAr»*.  and  <  onsetiuenti  v  will 


^eld.iiii  atTect  or  redu<"e  it  ii 


th 


enihryo. 


1  hun 


we  can 


understand  the  tjreater  relative  ni^e  of  rudirnent.iry 
or;:-;*!!*  in  the  einhrvt),  and  tlieir  lesser  relative  «-i/e  in 
tlie  idull.  Itut  if  each  step  of  the  pro.  ess  of  redui  iion 
Hereto  *>e  inlierited,  not  at  the  correspondiiii:  ai.e,  hm 
H'  an  extreineiv  early  period  of  life  («s  me  have  tood 
rea-nii  ro  believe  to  1h'  {wissihlci,  'lie  rudimentary  pari 
.voulii  tend  to  he  wliollv  lost,  and  we  should  hhve  a  ca.«e 


I  i. 


•  t.i< 


^n      i^t  <Ai*(  iri<  irr^  1' 


exj'lamed  in  a  former  cha[>ter,  liy  v^hich    the  materialu 
rornnug    anv   part   or  strmture,   if  no;    u-etul    to   Uie 


I 


410 


(»N     I  UK   oiSKilN    (1^    M'E(  IK- 


[„,sk(.,,or,  w^ill  ho  (<av('<l  a-  far  as  is  i>o«sih!o.  vrjl 
DiMhahly  ottf'ii  COM!*'  into  play;  and  tfiin  will  U-m 
i<>  faii-;p  tlie  entire  ofiliti'ra'ii  ii  of  a  nuiinientar' 
(iry.iii. 

As  the  pr<";t'ncp  of  nidirruMitarv  nri^aus'  is  tliii 
(in*  til  the  tiMiilency  in  «'vprv  part  of  the  nrtranis^ition 
«li:ch  hart  l»)n^  existrd,  to  he  infierited  »>•  can  under 
stand,  on  the  eenpalotriral  vjewo;  cla«sihcation.  how  it  i 
tliaf  «\  stiMr)ati«-t-  liave  found  rudimentarv  parts  as  u^efu 
as.  or  even  Horo'-tiniea  mere  useful  than.  ,»artj«  of  hiff) 
phyi-i jlotrical  importance.  Kiidiriifntarv  orirari^  mav  t.t 
«-oinnared  uith  the  letters  ui  a  word,  still  retained  ii 
itie  spelliriir,  l"it  he<-iiine  useless  in  tlie  pronunciation 
l>ut  whicli  ser\e  as  a  clue  U'  seekirii.'  tor  its  derivation 
<  hi  the  view  <)f  descent  with  modification,  we  may  ton 
cliide  that  the  existence  of  ori:ans  in  a  rudimentary 
imperfect,  and  useles.s  condition,  or  (juite  ahnrted,  fai 
fraui  presentmtr  ;•  str.iuijo  dithculty,  as  thev  ,issuredl\ 
do  on  the  ordinary  doctrine  of  creation,  imtrlit  ever 
have  heen  anticipaicd,  and  can  he  ac<-ounted  for  hy  th« 
laws  of  iulicritance. 


Suminnry.  -In  thi>  chapter  1  have  attempted  to.stiow, 
;hat  th*».suhordi nation  of  trroup  totrroupin  all  orjraniswif 
throua:hont  al'  time;  that  the  nature  of  the  relationslnp, 
liy  vvhii  ;,  ail  livintf  and  extinct  heimrs  are  united  hy 
lomplev.  nidiatinj;,  and  circuitous  lines  of  arfinities  inti 
one  ffraiid  system  ;  the  rules  fnlhiwed  and  the  difficulties 
encountered  hy  naturalists  in  'loir  cla.s>ihcations  ;  thi 
value  set  upon  charaiters,  if  constant  ami  prevalent, 
whether  ofliicfi  vital  importance,  or  of  the  rmtst  triflint; 
importance,  or,  as  in  rudimentary  organs,  ot  no  import- 
ance ;  the  Wide  opposition  in  value  hetweeu  anaioirical 
or  adaptive  characters,  and  cliaracters  of  true  atfinitv  ; 
and  other  -Mich  rules  ;  all  naturally  fullow  on  the  \ie',? 
of  tlie  common  jKirentatre  of  tho.se  f«»rms  which  are 
ct(n>-;dered  hy  naturalists  as  allied,  to^^elher  with  tlieir 
mddiiuaiinn  tiiriiu;:ii  natural  selection,  with  it-s  con- 
tingencies of  ertmction  and  diverjrence  of  char.octer. 
hi    considering    M  i-  view  of  cLi>-.-!:'.(alion,  it  Bhouhl    h*' 


Sl'MMAKY 


4il 


irno  ill   niinil  that  the  olemeiit  of  deooent  haa  i>eeri 

jiiivtrsaily  usfil    in  rankiinr   totjethor  the  m'XPf,  atce;*. 

i:;ri  aoknow!c(lii:«;d  varieties  of  the  sanir  r.pftie-«,  liowfvpr 

:i.*^ercnt     they   niay    he    in    structiire.       If  we   extent! 

:he  line  of  this  element  of  descent, — the  only  certainly 

;  .lowii  taii-e  of  similarity  in  ortfanic  U'iiitiH, — we  shall 

•:  ■tf'rstaiid    what    is  meant     hy    the   natural    system  : 

•    ;-   penealofjiral  in  iti  attempted   arrangement,  with 

1     irrade'^    of    ac(iuire<l     dit^ereme     marked    hy    the 

.  '^mM    \,trielies,  species,  t^etiera,   famIlie^,   <irder^,  and 

i-ipe-s. 

On   thin  -ariie  view  of  descent  with   rnodifi'-ation,  ali 

he  ;;reat   fat-t>*  in   Morphoio^'y   become  intelliyilile, 

h»v:.ir  we   look  to  the  same  pattern  displayed  in  t!ie 

i.uniiil'urous  ors^aiiH,  to  whatever  purpose  apjdie«l,of  the 

l.tferent  species  of  a  clasg  ;  or  to  the  homohiirous  parts 

Mnstru(;te<l    on    the   -..ime  pattern   in   eai  h   ;ridiv  ;dij.il 

t.'iimal  and  plant 

<  >u  the  principle  of  succes>i\e  slight  variations,  not 

ccessarily  or  generally  .■«uperveuing  at   a  very  e.irly 

.  iTiod  .>f   life,  and  W'intr  inherited  at  a  rorr»-spondunf 

;..'rii>(i,  we  can   iinder-<t;ind   t!ie  great  leadin^r  factjji  in 

i-in  »ryolui.'y  ;    namely,    the    r^>^enlhiaIu•e    m;    .m    ind- 

•  ntu:tl  enit>ryo  of  the  homologous  part.s,  which  v^hen 
f;a»'ired  will  hectiiui    widelv  differe'it   from   each   othrr 

;i  -fructure  and  function  ;  and  the  resemblance  in 
'irferent  species  of  a  cla.ss  of  the  honiolot;ous  j>art«  or 
iT^rans,  though  fitted  in  the  adult  n  •.•  ibern  for  pur- 
(inses  as  different  ;i-  pos«iili!e.  I«arvi^  are  active  ein- 
'ryos,  which  have  Itecome  specially  modjtied  in  relation 
■•  their  habiu*  of  life,  throii::h  the  principle  of  niodihci- 

(>!.-  being  inherited  at  r..rie«ponding  ages.  On  thi^ 
^.iiiie  pnncijde— and  liearui^  ii<  mind,  'hat  when  organs 
I'e  redu<  fd  in  si/e,  eitlier  trorti  di»:,-c  or  seli-ctu'ii,  it 
v.ii  t'enerally  t>e  at  that  period  of  lite  when  the  hen:;; 
f  i^  to  provide  for  its  own  wants,  .Uiii  tie^iring  in  mn  'i 
:i"'>v  siroug  Is  the  principle  of  inlientance-  the  «)ccur- 
■•■iice  ijf  ruUimeiiUiry  organs  .ti.ii    liieit   liuai  ai»orlion, 

e-ieit  to  us  no  inerplicabl,-  tl,rficuitien  ;   on  the  cou- 

•  'rv,  their  preM;nc«  mi,'<ht  tia-e  i>»^n  -v^eti  autic!i>ate  i 


I 


412 


ON    IHK   OKKilN   OF   SI' EC  IKS 


Iho    iriii'ortArice    of  pinbryolojjical  charartfru    atMi    o 
rudimentary  ortraiiH   in   rl.isHiticatioii   in  iiiti'UnriMe.  u 
the  \  le**  that  an  arranjfemerit  is  only  so  tar  natural  r 
it  ih  p»'nwii(ii,rii'al. 

KuihIIv,  the  «evf!r:»l  rlasses  of  facts  whicii  liave  Uh»i 
coiHiiiereri  in  linn  iliaptvr,  Mvrti  to  mh-  to  |tr<Hlaim  •<( 
plainly,  'liat  the  inniiineralile  wjiPcii's,  jrj'uera,  am 
fannlf's  of  orp^inic  hoin/s,  Aith  v\|iirh  thin  world  i 
pe<»[>l»Mi,  ha\»'  .ill  d«'j»r«*nde<i,  emch  within  it-x  own  das 
or  group,  from  romrnfm  panMitj*.  and  have  all  be«"i 
mod  H»*d  in  thp  rour**' of  d«\-(  ent,  that  I  should  witliou 
hft.xit.rit  «in  a/iopi  fhih  vi»'w.  *",cn  if  it  were  uiisiip[>ort«^ 
by  other  faobs  or  arj^-uinentH. 


M  4  T  ? 


SB?  'V-.  tM 


'r* 


i 


(HAITKH    \i\ 


H^•   API  I  I   I.ATll'^     AMI     I  (>N<  I  I  fc|t>> 

K'   \r>itiilatl.in  <if  tl.e 'i'TIi  ultlei  i.n  l!.'-  theory  cf  Sa:ur»l  yr'"^-t.cii 
!L(  ■•jiltiiUti 'ii  (.f  U;r  (fiTirra!  ir  •'  ijwi  iaI  l•l^■'llll^^«^■■l-»  in  ttj 
t.ivi>ur     I'Hiifrt   (,f    ifie   k-ftJ«T»l     I"  in-f    in    the    iiiin..ii»lnlii.y   u( 
»i><i  i<-»     H"4»    far  iiif   tjir.ry  '.f   imtur*!    •rl.-iiinti   n%\    tx-   ex 
t«i)  !••■]     KrTfi-U  rif  iu  fc.l')pti'>i.   in  Ui<  ilU'ly  i.f  nutiir.!   '    «♦.  ry 
C'oiK-luilInK  rt-nikrki. 

A"  this  whule  volume  !•<  one  loii^  arnunu'iit,  it  fp;iy  b« 
coiivonieiit  to  the  reader  to  ha\e  the  leadiiijir  fartj«  Hiui 
interencw  hrieriy  recapitulated. 

1  hat  many  and  werioue  ohjertions  may  Jk*  .'idvanced 
airniiist  the  theory  of  de«<eiit  with  inodifitalion  throuirh 
natural  selfi-tion,  I  do  not  deny.  i  liave  endeavoured 
t<i  trive  to  them  their  full  force.  .Vothiitjf  at  fir«t  i-an 
qipear  more  difficult  to  believe  than  that  tlie  more 
loinjdex  or^aiio  and  instincts  s^iould  have  J)efn  [H'T- 
tVctwi,  not  by  meai  ij>erior  to,  thou(;h  analotj<>u>.  with, 
h'.riian  reawon,  but  liv  the  accumulation  of  innumer- 
itde  sliffht  variations,  each  (rood  for  the  iiidivxlual 
]„,«,HSf*or.  .Neverthelesx.  tl.i.s  difficulty,  though  ap- 
["•irinji;  to  our  imatrination  insuwrabiv  jfreal,  <annot 
|>«'  'onsidered  real  if  we  a^lmit  the  foll(>wintf  propoHi- 
tions,  namely,  —  that  ^rradations  in  the  perfectinn  of 
^iiV  urtfau  or  instinct  which  we  may  consider,  either  do 
now  exist  or  could  have  existed,  each  iro<)d  «it   its  kind, 

that  all  ortraiis  and  instincts  are,  in  ever  so  hliifht  a 
,l..rrv«.  v»riahl»>,  — and,  lasilv,  that  there  is  a  >trii:rt?b- 
f"'  -existence  leadiujr  to  the  prewrvatiou  of  eadi  profit- 
;«f  le  deviaL'i»n  of  .structure  or  instinct.  The  truth  of 
t'lt'M-  propo^iUoni  cannot.  I  tliink.  1*  disputed 

4J3 


414 


ON    MIK   ()IU<;IN   «>K  .s|»K("IKS 


%-<! 


ll  1.-.  an  <iiiiilit,  e\Lrem«'ly  <iitru'nlL  p\f'ii  t<»  rcir*»ot  i- 

}<y    wlint  {jrad.itinriH   many  R^nut iin-s   li.m-    ln-cii    [•«• 

UiitT'l,    more    I'spoi  ;,il|y    ^tiio.i^rwt     hiokc"!     tinl     faiiii: 

irroiij>s  fif  ortT.iiiii'  Immiiit-*  ',   l»iit  wf  vcc  ^n   many  "^traiit 

trr;i«Utiuiis  ill   iinf.ire,   tli.it    wc  du^'lit    to   bo  t-xtrcmf] 

,1  i'io  .'  in  'viyiii^r  tli'^f  any  rtri^aii  or  in~tiii.  ♦,  or  ati 

vlmli'    liririi,',    rnulii    not    Im.m    arrived    at    it«    pr<»'-oi 

•ato  hv  iDiiiiy  Lcri'liiatod   Ktt'j>«.      'liuTf  .i'".   it  mu 

'!<•  a'imit'<'(!,  ra-«t»  'tf  sjjccial  ililliculty  otj  the  tlicor;."  ( 

natural  M-lortiou  ;  and  oiip  of  tin-  mf>»t  curioiK  of  tli.v 

1-  tliH  cit;-tpiic«'  of  two  or  thror  di'iirioii  ca-tc-.  of  .*orkp 

or  «teri!»'  fp'nalo«  in  \\ii'  >imo  rommiitiity  of  ants  ;    In 

1    liavc  attt'rnj>t«'<l    to   >liow   how    tliis  dilJuMiltv    lan    \ 

mastfrod. 

^\  itli  rosjiect  !o  llie  almost  uiii\»'rsal  sterility  ' 
•,.!>,  ies  wluMi  fir-t  crossed,  vvliich  forms  so  rcmarkal) 
I  contract  with  the  almost  tiiiivcrsal  fertility  of  >.ariotii 
when  crossed,  i  must  rj-for  the  rcnirr  to  the  recapitiil 
tion  of  the  lactM  trivon  at  the  end  of  th»'  eiL'^hlh  ihapto 
which  -e«'m  tt>  me  cnncliisi\plv  to  show  that  tliis  sterili' 
!■-  no  mure  a  sjMvial  end(>wm"iit  than  Ih  the  incajiacil 
■  )f  two  tppHs  t/)  he  grafted  toirether  ;  hut  tliat  it  is  inc 
dental  on  constitutional  ditferencP"'  in  the  reproducti' 
-ystems  of  tlie  intercros-ed  spec  ie>  We  see  the  trul 
of  this  conclusion  in  the  vast  d'lierence  in  tlu>  resul 
vheu  tlie  same  two  species  are  crossed  recipro'ali\ 
that  is,  when  one  species  is  tirst  used  as  t)ie  f.it iier  at 
then  as  the  motlier. 

Hie  fertility   of  variot 
tlieir  nioriirrel   ntT-;prinf; 

versal  ;  nor  i.s  their  very  ^•eiieral  fertilit\  ^nrprisii 
when  we  rememher  that  it  is  not  likely  that  eitli 
their  constitutions  or  their  reproductive  systems  phow 
liave  been  profoumlly  modified.  Moreover,  most  of  tl 
arietir-  wiiich  have  been  e\])erimetitised  on  liave  l>e» 


Hie  fertility   of  variotio-^   when   intercrossed   and 
-prinjr  c^aiuiot   he  cunsideri'd  as  ur 


»rndui 


jiider  domestication  ;    and  as  doniestLatif 


'I  do  not  nie^an  mere  confinement)  apparentlv  tends 
iiminate  stciility,   we  outflit   not   to  e\|»ect   it  also 
[iroduce  sterility 

The  stenlitv  of  hvhrids  i    a  very  ditfcrent  ra^o   'rd 


Hr;(  AlMIl  LAFIHN    aM)   ( ()\(  l.f'SK  tv    il.s 


.•.Id/   nr«t  crns^cM,  for   tiieir   ri'pn'ilurtive  <ir._'i'i-.  ii'>- 
-nd'p  or  less   tiinctionilh    im|t<.«i'iit  ;    »lu'n'.i.«»    m   hr-i' 
■r'-ses  tli»'  KPt;  iii>  oi:    iiotli   xnlp*;  are  in  a  |K"-'>-t  mn 
litioii.       As   w«>  coiitinii.illy   sfo   tli.it    oriraiii-iii-   of  al. 
-iiifin  an*   rcMi'lfri'il   iii   •"iTriP  (U'lrrc**  -tfriU*  fnuii  iIh-  r 
.  mi-'titiit.ons   having   hcpii  distu:  •••d    by  sKf'itlv  fl;rff 
fiit    aiiH    lu'w    ciiiiditions    of     lite,    «<•     in'i'il     imt     u'ri 
-  irpr  -'    at,   liv!iri<ls   K»'iiii.'   in   koiim'  dt'^'^rff  ■iN-riU',   for 
•h.ir   1  ..!i-.titiitioiis    c-aii    tiinlly    f.i'l    to   liiv.-   'i.wmi   <1m 
urlK'ii    from    l»«'iiiL'    roinpoiiiulf*!    "t    twi    <li-t.iiirt    or- 
.'aiii^atioiH.      'I'lii-  paralleli-m   is  sn|i;.(.rt»Ml  by  anolluT 
•■I'.ili.'I,  hut   dircttly  o|>i.oMte.  rl-i-s  of  fact-  ;    iiaiTU-iy, 
t.ii  tht'  viiToiir  and   fiTtilily  of  -ill   nri,',iiiii-   l)»-iiiir»*  ar»' 
■,-Tt'a-t'>l  i'V  -IiL'lit  fliatigj's  III  'ln'ir  i-oiniit.oii'*  ot    li:.-. 
i:id   that  tlie   otfsnriiiif  of   sliir^tly   inodilii'd    forms    or 
varieties  acquire  from   heiiitr  (TO-himI   increased   vijjour 
iini  fertility.      So  tli.'it,  on  tlte  one  liaiid,  cousiderali!.' 
■li.iiijre-i  in  the  (umlit.ons  of  life  and   i-rosses   l>el»i'ci. 
,'nMtlv   modified  forms,   lessen   fertility  ;    and   on  the 

ther   liand,    lessor   rhanires    in    the  conditions    of  lite 

id    crosse.-)    between     less    modified     forms,    increa.se 

nilitv 
I'lirnin^  to  (.^'oirrapliical   (i!>tritiution,  i  he  dilTicuIli''- 
.  ,.  oiiutered  on  the  theory  of  descenl  with  modificalinn 
ire  tfrave  eimnjrh.       AH  the   iiidividual.s  of  the   mime 

[H'cies,  and  all  the  upecies  of  the  s.ime  j.'enii'i,  or  even 
li^'^lu'r  jrruiiji,  must  have  descemied  from  common 
;>ar'-iUs  ;  and  therefore,  in  however  <ii-.t.int  and  isolated 
;).irt,s  of  the  world  they  are  now  found,  ihey  must  iu  llie 
•iHirse  of  successive  geiier.itioMs  have  passeil  from  some 
UK-  part  to  the  others.  We  are  often  whollv  unahle 
.'."•!i  to  conecture  how  this  could  h.i\  e  Keeti  effected. 
N  el,  as  we  iia\e  re^i-stMi  to  believe  tt'  it  -nine  «pecies 
'  :»ve  ntaried  the  s,ame  sj«»(ific  forin  lor  very  inna 
:>eriods,  enormously   Ion?  as    mea-ured    by   years,   too 

'luch  stress  outrht  nui  to  be  laid  on  the  occasional  wkIp 
;itfusi(in  of  the  same  species;  for  durintr  ver>  loin; 
iieriods   of   time   tiiere   wiii    always    iave   iieen    a   ^ood 

ii-mce  f 'P  Wide  migration  by  many  iiseaiis.  A  hrokei- 
'<r   'liter:  ir.'*ed   raiiire   may   often    he   arcouri'ed    for  b\ 


nc. 


ON     NIK    «  •KI(;iN    «  »F    >^|'K<  I  K.s 


iric  extiiirtiiiu  <»!  tin"  »|.<>i  ,,-  in  tlio  itibTim-  i.an 
rHtr;<»ii>.  It  r.iti'i'i!  In'  (ii'iiii-il  tii.iT  Hf  arf  a-i  \»*t  vtTi 
ijfimr.int  of  ttu*  full  o\'»'iil  of  tlif  *.irniii«i  ihiiiif.il  .•ni 
.re«ii.'r:i[iliir.il  rlirit!i.M—  whuh  K.ikr  af'crted  t>i»'  f.irtl 
d'lntiir  tiKxItrii  i>tri(Ml- ;  anti  "i':' h  «  i!,'iti;rt»  nili  nli 
viounU  have  tjrf.itiv  t'at'ilit.itfl  tiiiirratiun  A"  ai 
••\.»n, jiU'.  I  ha.»>  rtUfriiiiffil  to  '•hou  liovv  potoiit  liai 
ii<'»'li  'li"  'lifi  iM'lir*'  mT  tlit>  (il.iti.il  |>iTit>(i  nil  tli»'  >{\y 
triliul.nn  'H)tli  (if  tliH  ».i!ii>'  iiid  ot  rt'[irr»»'iit;4tiv( 
>j»«'i  "■■)  throiitrli''iit  iIm*  vvond  U  h  an'  ».•<  v»»»  pro 
tdiiiiillv  i^riioraiit  ot  th»'  iiiaiiy  oira^innal  u!*'.!!!"  o 
trans'port.  N\  ilh  rp-i>t»ct  to  (iistiiii't  -.|ni-i««..  of  ttn*  --itrK 
^piiu-  mil  lint  lU'f  \t'r\'  liistant  and  i-oii'cd  r»'i'iiiri«,  i' 
tiif  pro.  »•-■.  .ir  mn.iifiratiKii  (i:i-  n**"  i'-.-^iri! v  Ih»m.  »1i)W 
a!i  till-  •  .I'.Kix  lit  inmratMiii  will  it,i\n  U»«mi  po-"<ild( 
d  .mil,'  ,1  \»Ty  li'ii;.'  ['(tiimI  ;  and  <  oii>-»'i|'it'fitlv  tli« 
■  1  till  uit\  of  the  wide  dirfuKiuii  of  sjM'cic-.  of  lli»>  -  uni 
-eiiux  iH  III  -uriu'  d<'irr<'«'  lt'>><'!i»»d 

A-  on  the  t h»*ory  of' iiaturi!  -i-lt'ction  in  iritcrnunaidi 
iiiini'wr  of  int^Mrnodiate  forms  n\\i>l  liavt'  exivt*'!! ,  lirikiiij 
totTBttier  all  the  »pp<i''s  in  eai-h  uroup  hy  irrad.it lotis  a; 
tino  as  our  prost'iit  vari»'t!P>*,  if  niav  )•••  i^Hi'd,  Why  d( 
w»>  not  -t'p  tht'-^e  linking;  forms  all  aroiiml  im  "  Win 
are  not  aii  orjfanir  in'inyN  hU-nded  tOiT'-ther  in  an  iiifx 
tri«'a('le  ••liao-«  r  NV'ith  rp»[M*.t  ^o  pxistnij;  tor:)-.  w( 
should  rpin»'Tn!>pr  that  we  h.f  i<  no  riyht  '<i  cxpec 
ipx'<'[>tinj{  in  rare  casps)  to  (iisC(i\or  dtrfi-th;  coiineclinj 
links  l)et\v«'»'ii  ilu'in,  hut  onl\  hetween  ea'.h  and  >oirn 
»'\tiinM  and  supplanted  form.  KNen  ou  a  w  df  area 
whiidi  h.t-;  duririif  a  Ion::  ponod  rt'mained  contniuous 
and  of  which  the  climate  :uid  other  i  onditions  of  jifi 
ctianije  iiisensihlv  m  coin^  from  a  district  occupied  l>i 
one  spfcios  into  iimther  (Ji^trict  occupicii  hv  a  cln-.fli 
ailii'd  species,  we  have  no  iu«t  riuht  to  exj>e4-t  often  t< 
find  inlermedi.ite  varieties  in  toe  in'ermediat*  /one 
V^^r  we  h.ivo  re-a-oi,  to  helieve  tiiat  ouiv  a  few  -pecic 
are  underLM)inir  chantrP  .if  .'iriy  «»ne  period  ;  .ii.d  a! 
ciiatu'fs  are  sioviJv  eftrcteii.  1  have  also  »fi((wn  th.'i 
tii>'  nitcnnediafe  varieties  which  "ill  at  first  orotiald] 
exist    III   the    intermediate  ^ones.    will    l>e  liahie  to   b< 


Kh(  Arm  l^llON    AM)   ((>N(  U  MON     U7 

■  •;i|il.iiil»«l  li>  tilt'  allif«l  furtii-i  mm  ••iflier  haiiil  ;  anti  tlie 

.  .'^ivr,  troiii  I'vi^titiif  ill  trriMii-r  iiiiihIxt^,  will  ct'in'railN 

■■*i  tiKMlitii'tl  anil  itupruvitj  at  a  (jun  k»T   rate  tliaii   tlii 

;;t'Tiiifi|i.itr  varictirs,  uliicli  rxi-t   in   l«'-,-fr  iiuTiil.t>r«  ; 

■  tii.il  tin-  intt-riiu'iliatc  v.iru-tn-^  v*,ll,  it;  i}i»«  lonir  run. 

•  -liiiplaiit*"'!  ami  ••xtermiiiati'il. 

«  »;.  lluM  ilot  tr.iif  «)l  tluM'xtrriiiiiiatioii  .,f  ,in  iiiiin.tuii.- 

.if  •■n:iii(.,-tintj  links,  Ki-lwri'ii  the  livin;;  and  ••xtin.  t  in- 

li'  l.iiiLv  i)t  tl  f  World,  and   at  ••acli   Mj.««'v>.i\t>   (xthhI 

t'>vfcn  tlif  extinct  and  htiil  <ild.T  !»ii«'.ic!4,  win   i-.   ni'- 

•  iry  Cfid. laical   lormation  i  liaPLM-il    with   «ii»  li   link- 
liy  dm,  nut  e\ery  ioll«Tiii.M  (»t    fn^sil   retiiains  alldid 

^i.ii  i-Mdiiire  of  the  irradatJMn  and  iiinUfiini  i>f  the 
-  iii>   or    li;.'.'     ^\'e  tneel  VMth    no  sn.  h  evidi-nit',   and 

M«  i*    tin'    iii(i--t    (divinus    and    turcilde    of    the    man. 
• 't  fHin-    whiih   may    l«    ur^'cd    at'ainst    my    tlu'tir) 
^    ly.  a-am,  do  whole  tfroup!*  of  allied   t*|W'.ieH  appiMr, 

•..'HiL'li  fcrlainiy  ♦'.••y  often  fal-ely  ajipcar,  to  h;i\e  .oii.e 
I  M'ldd.'nly  on  the  heveral  t;'''>ln^-icai  sUt-es  r  \\  \,v  d«. 
'■  init   imd   trreal   piles  of  straUi  l»eiu'ath  tiie  >iliirian 

-   -tciii,    vi.ued    with     the    remains   of  the    proL'enitijr.s 

•  li:e  >ilunaii  groups  of  fosMls.-  For  ceM.nnly  on 
: :i\  theory  Mirli  Htrata  must  somewhere  ha\e  heen 
we|H.N;ted  at  these  aniient  and  utterly  uiiknoHu  epueli- 

•1  the  World  s  history. 
I   can  answer  tlu-^e  <juestions    and   ura^e   ohjcetion.-. 

•  '  i!y  <in  tiie  hupposition  that  the  ^eoloj.Mial  record  is  far 

•  lie  onperfc.  I  than  ini.st  ^e<docistfi  helie\e.     it  cannot 
•'  olijecled  that  there  hajt  not   l>een   time  sutheieiit  for 

'  ly  amount  ot  ortrani<-   charitre  :   for   the  lajiM)  of  time 

L-  heen  so  :;reat  as  to  he  utterly  inappreciahle  hv    the 

itiian  intellect.      J  he  numU-r  of  hjKjeimen^  in  all  our 

."j^einns  is  ahsolutely  a.s  nothing  comjured   with  the 

■  "uiitless  generations  of  vountle^H  specie^   vvhjcli    eer- 

t.iiiily    ha\e     existed.        We    should     not     l»e    aide    to 

ui  ..^Mii.-.e  a  HiKJcies  a-s  the  parent  of  any  one  or  mt.re 

'i'*'tie«4  if   we  were   to   examine  them  ever  .so  cloM.dv, 

linh'-i^i  ivi-  Hkewice  t..v--e^-e.!  -.-.-.-.-.■  ..f  -.'....   :..t, ;;„! 

i.nks  lH''we»'n  their  j»;».st  or  parent  and  pre.sent  states  ; 
••'■id   t!ie>e  many  link:*  we  couUl   hardly  ever  exi»ect  to 


418 


ON    rHK   OKK.IN   OF   SPECIES 


IV 


-f 


(iisrover,  owiiiif  Ld  lh<'  iiripertVctioii  of  thti  jr'M^'ojfical 
rei'inl.  NuiiirroiH  exi^tiii;.'  duuldml  fornn  ••ould  be 
uwikmI  which  ;ire  prohahly  variotios  ;  hut  who  will  pre- 
t«-ii<i  that  III  future  airi*s  so  tn..riy  fossil  links  will  \)e 
discitvpred,  tliat  nHlar;ll^•^t.s  will  he  ahle  to  <le<  id**,  on 
till!  (0111111011  view,  whether  or  not  tliese  dinihttul  rormn 
are  variftien .'  As  Ioiil''  hx  most  of  the  links  hetHt'»;u 
anv  two  species  am  unknown,  if  any  one  link  or  inter- 
mediate variety  he  discovered,  it  will  simi'ly  he  classed 
as  another  and  di->'.inct  sp»>,icfl.  ( )iily  a  -iiiall  portion 
of  the  world  has  heeu  ^eHl((;:;cally  explo.-ed.  Only 
orLMiiic  heintrs  of  certain  clar«.-.es  can  he  preserved  in  a 
fossil  condition,  at  lea-st  in  any  irreat  numher.  Widely 
rui^anu:  sjH«cies  vary  nio«t,  and  varieties  are  often  at 
first  Incal,  — both  causps*  renderintr  the  discovery  o1 
intermediate  linkn  less  likely.  bn-al  vaneues  will  nol 
spread  into  other  and  dis.^int  retr'oiis  until  they  are  con 
siderahly  modified  and  improved  ;  and  when  they  dc 
spread,  if  discovered  in  a  tjeolo«ical  formation,  thej 
will  appear  as  if  suddenly  created  there,  and  will  b« 
pimply  chi-ssed  as  new  species.  Most  formations  hav( 
been  intermittent  in  their  ac-cumulation  ;  and  theii 
duration,  i  am  inclined  to  believe,  ha.s  been  shortei 
than  the  avenuTP  duration  of  specific  forms.  Succes,siv« 
fi.rmations  are  separated  from  ea-h  other  by  enormoui 
blank  intervals  of  time;  for  fossiliferous  formations 
thick  enou;ih  to  resist  future  det'radation,  can  \h 
accumulated  only  where  much  sediment  is  deposited  oi 
the  subsidintf  l>ed  of  tlie  sea.  Durintr  the  alternat4 
periods  of  elevation  and  of  sUitionary  level  t)ie  recori 
will  l»e  blank.  Duriiiir  these  latter  jMiriods  there  wil 
l»rohably  be  more  variability  in  the  forms  of  life  ;  durinj 
j)eriods  of  subsidence,  more  extindioii. 

With  rer-pect  to  the  absence  of  fossiliferous  forma 
lions  beiie.ith  the  lowest  Silurian  strata,  I  can  onl; 
recur  t.i  the  hypothesis  tfiven  in  the  ninth  chapter 
Til  it  the  jfeolo;ri,-;il  record  is  irn|terfect  all  will  admit 
but  liial  il  i:'  inipt-rfert  to  the  dcirnu  whli  h  !  require 
few  Will  be  incluievl  to  admit  If  we  look  to  lonj 
enonirh  intervals  of  time,  j^eoioj^  plainly  declareu  tha 


H^iS 


,  *'» 


RKCAI'ITULATION   AM)  C()N(  Lf'SION   419 

tM  •^^•'i-ies  havB  c-haiit:t'il  ;  and  thpy  havo  ciiainr,..!  m 
•h"  miiiner  w'nich  rny  tlicory  reijiiin-*,  for  tJwy  i.ave 
ch.iiitfe'l  slowly  ami  in  h  trr:i.liiat*»«l  maimer.  W  »• 
.•!»*ariy  M-e  this  in  the  tnssil  remains  fritm  con-eriitiv 
*'nrmati«)ns  invariably    l>eiii;f  niiiili  ninrt*  clovi  Iv  ri-\,\'f>\ 

■  ♦Mth  other,  than  are  tlie  f<)s.sils  from    fcrjiia'.i'i'is  liis- 
•..;i'  frnm  ea.'h  ntliPir  in  time. 

.">Ufh  1^  tlie  mini   of  tlie  several  chief   ohie«t;i(ii-i  and 

i:fh<-iiiiies    which    miy    justly    l»e     iiru»'<l    a.i:aiii-l     niv 

iieory  ;  and  1  lia\e  now  hnefly  recajntiiiated  tlie 
.ui-rters  and  eii<ianati(tiH  wliieh  .an  be  tri^en  to 
Ihem.  I  hav..  (V-Jt  these  dith.ultieH  far  1»mi  h.-avily 
durin?  many  years  t<»  doiiltt  tlieir  weij/ht.  Hut  it  de'- 
-<Tves  e-pecial  notice  that  the  more  iniportunt  o!)).'c- 
t  (ius  relate  to  (juestionw  ou  which  we  are  (•onfe*v,.,ilv 
is.'norant  ;  nor  do  we  know  how  itrnorant  we  are  U'f 
''.>i  not  know  all  the  |.o>*ihle  t.-ansitional  gradations 
l.ttween  tlie  simplest  and  the  most  '.erfect  orirant  ;  it 
I  iiiiiot  he  pretended  that  we  know  all  the  varie<i  means 
ot  i>i>lrihutioii  durinfr  the  lon^  laps*,  of  vears.  or  that 
we  know  how  imjwrfeet  the  (Jeoloyiial  Record  is. 
•  .rave  as  these  several  dirticultips  are,  in  my  jmi^rment 
they  do  not  overthrow  the  theory  of  descent' from  a  i.-w 
credited  forms  with  suhsequent  moditicatitin. 


I 


ii 


N(.w  let  us  turn  to  the  other  side  of  the  arjfument. 
i  iider  drmiesticatiou  we  see  much  variahility  'Iliis 
•ieeiii-  to  he  jnainly  due  to  the  reproductive  system 
heint;'  emiiietitly  suseeptihle  to  chan>fes  in  the  condi- 
tions of  life  ;  so  that  this  system,  wlien  not  rendered 
impotent,  fails  to  reiiroduce  offspririj;  exa<-tlv  like  the 
partrit-form.  \ariahility  is  ifoverned  hy  many  compler 
iaxvs,  -  l,y  correlation  of  trrowth.hy  use  and  disu-e,  and 
l»y  the  direct  action  of  the  p}iys;cal  condition?,  of  life. 
I  here  is  much  diffieulty  in  a.-^rertaining  how  rnuch 
:iiodificat;on  our  domestic  productions  have  iiniier;roiie; 
i.ut  we  tnav  safely  infer  that  the  amount  has  Iwen 
"iTpre,  aau  tnat  iiimlihtrrtliuns  can  i>e  infieriu-d  (or  ioiijf 
jteriod-i.  As  loiitj  as  the  conditions  of  life  remain  tlie 
-ame,  we    iiave   reason  to   l>elieve  that  a   m(»difi.atio:j 


.-t,^ , 


"^ir  il:  ;■ 


420 


ON   THE   OKKJIN   OF   SPECIES 


which  has  alrt-afiy  hcou  iiiliLTitod  for  many  treiioratioFH 
nmy  roiilinup  t<»  1»»>  inherited  for  an  almost  intiiiit* 
iiutn?«>T  of  ^'^•MH>ration>4.  On  the  otiier  l)u;ui  we  iiav( 
evidetu'p  tliat  varialulity,  when  it  h.m  onco  come  iiiU 
play,  liopx  not  wliolly  coa-c  ;  for  now  varieties  are  stil 
occosiiinally  jiroduced  hy  oiir  ni(i>t  aniieiitlv  domesti 
I'ated  |ir(Mlijcll<ins. 

Man  (iocs  not  aitually  .rodu'-e  variahilitv  ;  ho  oiih 
iiiiintontionally  exposes  oriranic  l»oiii{rs  to  new  condi 
tions  *)f  life,  and  then  rature  acts  on   the  ori:anisation 

i.id  causes  \aria!iility.  liut  man  c^n  and  does  spjpi  i 
ttie     \ariations    jriven     to    hirn     hy     nature,   and   thu- 

icciMiitilate    tliem    in    any    desired    manner,      lie  thu- 

uhijits  animals  and  nlants  for  liis  r>;vn  honefit  (»i 
pleasure.  He  mav  do  this  methodi(a!ly,  or  lie  mav  do  i1 
uncon-.'iou'iy  hy  pre-c>rvinjr  tlie  individuals  most  usefu! 
(  )  liiu)  at  the  time,  witliout  any  thoutrht  of  alterii:;;  tin 
l'r«  cd.  It  i".  certain  that  he  (an  lar^'-ely  influence  tlw 
I  haracter  ot  a  iipeed  hy  Kelectinj;,  in  e.n  h  successive 
■  eiieration,    individual    ditference**    so    slitrht    as  to  \h 

juito  iiiaj)precialile  hy  an  uneducated  eve.  1  Itis  jir(R'es« 
of  '-election  has  Kten  the  trre.it  aiT'-ncy  in  the  prmluc- 
tion    of  the  ino.st  ijistinct  and   useful  domestic  hreeds. 

'"hat   many  <»f  the  lireeds  produced   hy  man   have  to  n 

artre  extent  the  character  of  natural  sjiecies,  is  shown 

>v  the  inextricahle  <iouhts  whether  very  many  of  their 
are  varieties  or  ahori(;inal  sper..:)S. 

There  is  no  (dsvious  reason  why  the  jirinciplos  whidi 
Save  acted    >o   ef'i'iently    uinler   domestication  should 

I'-t  have  acted  uruler  nature.  In  the  preservation  ol 
MS  oured  individuals  and  races,  during  the  «;onstantly- 
'ccurreut  Strui:::h'  for  I^visteine,  we  see  the  most 
powerful  an<l  eve.'--actiutr  means  of  selection.  'Hi* 
striiiTi^le  for  existence  inevilahly  follows  from  the  hijrli 
tjeonietrical  ratio  of  incre^ise  which  is  common  to  all 
or^-anic  heing-s.  This  hijrh  rate  of  increase  i.s  proved 
•ly  calculation, — l,y  the  rapid  increase  «if  many  animal* 

md  plants  during  a  succes.sion  of  jHJci.liar  sea.sons,  or 
when  naturalised  in  a  new  country.  More  individuals 
are    l»orn   thati   can   possihly   survive.      A  errain  in   the 


KECAIMTl'LATlCiN    ANF)  {'()V(LUSI(  >V    421 


or 


t.,tiain«-  will  dpffriiime  which  individual  shall  live  at  •! 
wliirh  shall  die,— v^hich  van»<ty  or sixnioH  shall  iiicrca-. 
ill  iiiiniher,  and  which  shall  docreaso,  or  finally  Iwvome 
'itiiirt      Ah  the  individuals  of  the  Rame  Hpecies  come 

I!  nil  resp(>rt.«  into  the  closest  comj)etition  with  »'ach 
other,    the    strii:.'j;le    will    jfenerally    he    most    sevt-re 

•I'tweeu  lh<'m  ;  it  wil'  he  almost  e(|ually  severe  ^letweon 
the  varieties  of  the  same  s[>ecies,  and  next  in  severity 
Wrtwoen  the  species  of  the  same  serins.  Hut  the 
■trii;r?le  will  often  ho  very  Ke\ere  hcluecn  heintrs  mo«.t 
remote  in  the  s«aie  of  nature.  I'he  slightest  advantage 
111  one  l>eintr,  at  any  nee  or  during:  any  season,  over 
i.'ioso  witli  which  it  comes  into  competition,  or  Wtter 
i.i.iptatiori  in  however  slijflit  a  de^Tee  to  the  sur- 
roundinff  physical  conditions,  will  turn  the  halat>.  e. 
\\'ith  animals   havintr  separate*!   sexes  there  will   in 

iost  cases  he  a  Htriit'trle  hetween  the  males  for  poswes- 
-loii  of  the  females.  llie  most  vigorous  iiidividu;ils,  or 
'tiuse  winch  have  mont  successfully  stru^^'led  with  their 
"tnditions  of  life,  will  tfeiierally  leave  most  protreny 
I'.ut  success  wiii  often  depend  on  havinjr  special  weapon- 
"C  means  of  defence,  or  on  the  charms  of  tlie  males  :  nn-' 

■ic  sliijliteiit  advantag'e  will  lead  to  victory 

As  trcolotry  plainly    proclaims    that    each    land    tia.i 

undertrone  tjreat  physical   chantres,  we  mi^hr   have  ex- 

[lected   that   orfranic   heuijfs  would    have  varied   under 

nature,  in  the  same  way  as  they  generally   have  varied 

•inder  the  chainred  conditions  of  domestication.     And  if 

ti  're  l*e  any  variahility  under  nature,  it  would  Ix-  an 

.laccountable  fact  if  natural  selection   had   not  come 

Mto  play.     It  }ia3  often  been  asserted,  hut  the  assertiou 

"  <iuite  incapahle  of  proof,  that  the  amount  of  vanatioi, 

wider  nature  is  a    strictly    limited    tjuantity.       Mrin. 

thoutfh  actsnp  on  external  characters  alone  and   ott.u 

ai>riciously,  cm  produce  within  a  short  f>eri>>d  a  g-reat 

result  l»y  adding  up  mere  individual  ditterences  in  lii- 

damc-Htif-  productionH  ;  and  every  unc  adiiiiU'  lual  there 

ire  at  iea>t    individu.-il    dilTerence>    in    species    under 

mature,      liut,  besides  guch  differences,  all  naiuralisfx 

Nave  Hdmitte<l  the  exi»ten<-e  of  vanetie-s,   which   thf^v 


* 

I 
I 


'  'I 


4 -"J 


<    s     I  UK    oinciiv    OK   S|>K(  IKS 


fi 


thin).  -  ifViririitly  d'-^tinct  to  tip  wnrtti)  of  rt'.nrd  ;i 
ly-itiMiMi,!  work?*.  No  ntir  'an  draw  aiiv  rlcar  (lis 
tiiii-tKiti  lii'twi'oii  iriHi' idu.il  dir!.  rfni'es  atid  <\\j)] 
v.ir.eticx  ;  or  i.elwferi  morf  |il;iiiily  inarknl  \;ir'c  le 
and  •"jl>-<:j.(Mit'>j,  and  Hj.rcii-H.  |>'l  it  Iw  «)|.M.rv«-(i  Imv 
iiif iirili-u  ditfpr  in  th»'  rank  which  tlipy  a-- lmi  ti 
tin-  many  repri'Heiitative  fiTtrif-  in  Kur()|;e  and  Nortl 
Ari.crira 

If  ttiHii  we  have  uiidrr  -latun'  varialtility  a-id  ; 
pfiw»'rful  atrrnt  alway«  ready  to  art  and  v,.le<t,  wh' 
'ihmild  HP  doiiht  thai  varia'tnrm  irj  anv  way  iiMrtul  ti 
lii'intrs,  undtT  tlirir  exros-ively  conndex  relations  n 
litiv  wnuld  l>o  pH'sorved,  ar<umulat«*d.  and  itiliented 
V^  iiv,  if  man  ran  hy  |(atiiMicf>  sph><-t  \ar:aii(»n.H  m-c 
tinrful  to  hiinoplt',  should  nature  fail  in  Helectinjf  varia 
tinn-^  u-pfiil,  under  charurinjr  ('(niditionp  of  life,  U 
her  liviuif  pr-.durt'! .'  What  liniit  can  l)f  piit  tn  ttiii 
poAfr,  aclitij.'  diirini?  loii^  a^oH  and  rijfidly  Hrrut;rii-i;nj 
the  whiile  constitution,  fitrurtiire,  and  hahitH  of  eacl 
creature.  -  fa\tiuriiie:  the  t'ood  and  rejecting  the  had 
I  can  set'  no  linut  to  thin  {M>wer,  in  slowly  and  heauti 
fully  adapt intf  each  form  to  the  most  complex  relation! 
of  jitc  r]i.>  theory  of  natural  selection,  even  if  w« 
looked  no  further  thar»  this,  seems  to  me  to  he  in  itsel 
prohai.le.  I  have  already  recapitulated,  M  fairlv  ax  J 
could,  the  opp«i«ed  dillirultie*  and  ol>jection9  :  iu<vk  lei 
us  turn  to  the  special  facts  and  arj^umeutfi  in  favour  o 
the  theory. 

i  )ii  the  vie«  that  species  are  only  stronglv  market! 
and  |H'rmanent  varieties,  and  that  each  s|>ecie«  firsi 
ei  Kfed  as  a  variety,  we  rarj  net  why  it  ifl  that  no  linf 
itt  demanation  can  !>e  drawn  V»etween  species,  com- 
monly supposed  to  have  ho«ni  produ<pd  hy  special  actf 
of  creation,  and  varieties  which  are  acknowledged  tc 
have  heen  produced  hy  secondary  laws.  On  this  sam* 
'•iew  we  can  understand  bow  it  is  that  in  each  re*>ioi] 
where  inanv  species  of  a  irenus  have  Iwen  produced, 
and  wjiere  they  now  liourisli,  tliese  same  sjHH-ies  nhouid 
present  many  varieties  ;  for  where  the  manufactory  o^ 
species  has  heen  active,  we  mijfht  exj)e<t,  a«  a  jfenera] 


ii^:- 


ti}#^.;vdr 


•KiiE' 


KK(  Arrn'LATlON    AND  (  ()N(  IXSK  »N    42.1 


r<iU'.  to  find    it  Ptili    in   actudi  ;  and   tins  is  tlu-  rasp  if 
%.'iri»'tii'«<  !)«•  iiH'ipiciit  sjK'cjpK.      .M()r»Miv»T,  tin*  -jmv  i«>~  of 


'h<'   cliarniter   of  \arieli«': 

(itlur  i>v  .1  1»'»'>  aTTiouiit  ot' ditT»TPin"e  tliati  di>  iht*  ^\>* 

of  «rii;tll»'r  irciM'ra.       Ilu*  rlo-tlv  allied   s| 


1  ♦'  lar:.'»>r  tretiera.  wliicli  afford   tlie  trri'.tter  mmil'»T  of 
.Lrit'tif>  i»r  m(i|ii»'iit  ^jm-.h—.  rft.iiii  to  a  ( t-rtaiii  (ifi:r('t' 

for  ihoy  dii't-r  from  t-arli 
1itf»TPin"e  tliati  do  ihf  .>.i>«'i  m«s 
I'lo-tly  allied  sjkm  ;es  aUo  of 
tht'  lartjer  j^'Oiiera  apparoiilly  have  restrn  t»'d  ranir<'^ 
:ii.d  ill  tln'ir  atliiiiti«'.s  thev  are  <lii-.t«>red  in  liUlt-  krroujis 
round  «)t}ier  >ipe(  ii's — ifi  wliicli  rt'spert**  thoy  rescnil.lt' 
v,iri»'tie*.  Ilieso  are  strai'tr**  relations  on  t!io  ^  icw  oi 
omh  s(»«M'ie^»  liaviiig  In't'ii  indejMMidoiitly  created,  lnit 
;iri'  ii'*<>l!i|;ililn  if  ail  -jiecies  first  existed  ;i.-  \arietie.-. 

As  tncli  spe«Me^  tendM  by  itH  jjeonietrnal  ratio  <it 
re[(r<>(iij(tion  to  iin'rease  inordinately  in  niiinlier  ;  and 
i«  till'  riioditie<l  desrendanL*  of  each  speeiej-  will  In- 
''iiaiilcd  to  increase  by  so  nuirh  the  more  as  tliey 
'M'come  diversified  in  haliits  and  structure,  imj  as  to  t>e 
«'nal)le«]  to  seize  on  manv  and  widely  different  {>lare'» 
ill  tlie  ecotiomy  of  nature,  there  will  l»e  a  consUmt 
teiidencv  in  natural  selection  to  pre-sene  the  nio>t 
'iiverifent  offspring  of  any  one  kjkh  ies.  Hence  during: 
a  lunir-continued  course  of  modification,  the  slijrlit 
ditferences,  characteristic  of  \arietie«  of  the  same 
••jK>cieH,  tend  to  he  autfnionted  into  the  greater  differ 
•'iices  characteristic  of  species  of  the  same  jjenus.  New 
and  improved  vanetieH  will  inevitably  supplant  and 
exterminate  the  older,  less  improved  and  intermediate 
varieties ;  and  thus  sjiecies  are  rendered  to  a  lar^re  extent 
detiiied  and  distinct  ohje«ts.  Pominant  «pecies  helontr- 
iiiif  to  the  larjfer  jrroups  lend  to  jfive  hirth  to  now  and 
dominant  forms;  so  that  each  larjfe  ilT'iup  tends  to  be- 
come still  lartrer,  and  at  the  same  time  more  di\er>fent 
in  dianuter.  Hut  as  all  g-ro'ips  cannot  thu*  succeed 
in  iricre.isinir  in  size,  for  the  world  would  not  hold  them, 
the  more  dominant  jfroups  l)oat  the  less  dominant. 
I'his  tendency  in  the  lartre  groups  to  ett  on  increaxinjr 
in  sj^e  and  diverjfinff  in  character,  totfcther  with  the 
almost  inevitable  contingency  of  much  extinction,  ex 
plains   the  arrau^^einent  of  all   the   forms  of   life,   in 


A;^ 


^^-  .a'  f  '■  o^.^>?  ■  -■-',  <r-ik^tu^  -M,  ■ 'l^-. 


424 


ON    TIIF    ()IU(;[\   OF   SPK(  IKS 


=  i> 


;n'nup'<  sulionliiiau-  to  tfrnup,,  .ili  v,ah'in  a  few  trn-a 
(■l;u«<s«>s,  which  \ko  now  s»'f  evervwliert-  around  us 
urnl  whi.li  has  prevail.Ml  throutrliout  all  time.  Thi 
Hr.iud  tact  of  the  ffroupiritf  of  all  ortfanic  heiiur 
seems  to  me  utterly  inexplicable  on  the  theorv  o 
<  reation. 

Am  natural  selection  acts  solely  bv  accumulatim 
'Ii^rht.  successive,  favourable  varialioris'.  it  can  [>ro(lur< 
no  trn-at  or  suridcn  moditicatio'i  ;  it  can  act  only  h\ 
\  cry  short  an.l  slow  stejis.  Hence  the  canon  of  'Natur; 
non  facit  saitum,'  which  every  fresh  addition  to  oui 
knowledt,'e  tends  to  make  truer,  is  on  this  theory  simpls 
intelhirilde.  We  can  plainly  see  why  nature  is  prodiira 
in  varu'ty,  thouirh  niLTirard  in  irniovation.  IJut  wlij 
this  shouhl  be  a  l.iw  of  nature  if  e  ich  species  ha^  been 
iiuie[»endently  created,  no  man  cm  explain. 

Many  other  facti  are,  a.s  it  seems  to  me,  explicable 
on  this  theory.  How  stranjfe  it  is  that  a  bird,  undef 
the  form  of  woodj.ecker,  should  have  l)een  created  t(j 
prey  on  insects  on  the  ground  ;  that  upland  ::eese. 
wliich  never  or  rarely  swim,  should  have  U-en  created 
with  webbed  feet  ;  that  a  thrush  should  have  been 
create.l  to  dive  and  ft-e^l  on  sul>-aquatic  insects;  am' 
th;.t  a  petrel  should  have  been  cre.ited  witli  h  iKit-s  and 
structure  fitting'  it  for  the  life  of  an  auk  ..r  L'rel)e  !  and 
so  on  111  endless  other  cases.  Uut  on  the  view  of  each 
species  constantly  trying?  to  increase  in  number,  with 
natural  selection  always  ready  to  adapt  the  slowlv  vary- 
irii,'  <le-.  eiidants  of  each  t4»  any  unoccupied  or  ill-occu- 
pied f)lai-e  in  nature,  these  facts  cea.se'  to  be  strange, 
or  perhaps  mi:rht  even  have  been  anticipated. 

Ai  natural  selection  .-.cts  bv  competition,  it  adapt- 
til.  mhabiUints  of  each  country  tuily  m  relation  to  the 
de-ree  of  perfection  of  their' a-s^oiiatc- ;  so  that  we 
need  feel  no  surprise  at  tlie  inhabitants  of  any  one 
••ountry,  althoui^h  on  th(>  ordinary  view  .supposed  to 
iiave  been  specially  created  and  adapted  for  that  coun- 
try, beiiitf  beaten  an.l  supplanted  by  the  naturalised 
productions  from  another  land.  Nor  ought  we  to 
marvel  if  all  the  contrivance^  in  nature  be  uot^  a."  tar 


;k;/i*"'!'^--;ilSfcte;&^-' 


■i-  'l-^ 


^W  ii\n:-- 


R^ilSPSl^itw 


RE(  APITULATION    AND   (()N(  LI'S<1(  )N    425 


>-  >u"  f.in  jti(lu:»'.  a^isolutely  perfpct  ;  and  if  udme  of 
thtTii  l»e  atthorront  to  our  iilf.m  of  fitness.  ^^'»>  iieesi 
nor  ni.irvel  at  the  stinjf  of  tlie  bee  causing'  the  bei'H 
iivti  death  ;  at  drones  heiii.'  produred  in  .siii  h  \aHt 
li  iiiihtTH  for  oi;f  sintrlc  n  t,  with  t}ie  jfreat  majoritv 
-i.iiichtered  by  their  sterile  sistors  ;  at  the  ;i.-tonishii;< 
vsasto  of  pollen  by  our  tir-trees ;  at  the  in.stinctiv«s 
hatred  of  the  (Hieeii  bee  for  lier  own  fertile  daujfhters  , 
it   ichnennionidit*    feedinir    within    the    live    boilies    ol 

■  atcrpilLars  ;  and  at  other  such  casen.  'Die  wonder 
Muleeil  is,  on  the  theory  of  natural  selection,  thai 
more  oases  of  the  want  of  absolute  j)erfe«-tion  have  not 
!>een  observed. 

Tlie  complex  and  little  known  laws  iroverninK  varia- 
tion are  the  same,  as  far  as  we  can  see,  with  the  laws 
whiih  have  governed  the  prodiution  of  so-ealled  specific 
. orms.  In  both  rases  physical  conditions  seem  to  have 
produced   but  littlr  direct  effect ;    yet  when   varieties 

■  nter  any  zone,  they  occaHionally  assume  some  of  the 
1  h.iracters  of  the  species  proper  to  that  zone.  In  Ivpth 
varieties  and  species,  u.se  and  disuse  seem  to  have  pro- 
il  iced  some  effect ;  for  it  is  difficult  to  resist  this  con- 
(lusion  when  we  look,  for  instance,  at  the  lo({'|^er-hcade<t 
luck,  which  ha.s  wiuj^s  incapable  of  Hitrht,  in  nearly 
he  Hiime  condition  as  in  the  domestic  duck  ;  or  when 

>*>  look  at  the  burrowiiiij  tucutucu,  which  is  occasionally 
hlind,  and  tlien  at  certain  moles,  which  are  habitually 
'il;:id  and  have  their  eyes  covered  with  skm  ;  or  when 
■*H  look  at  the  blind  animals  inhabitinir  the  dark  cav«vs 

>t  .Vmerica  and  Europe.  In  both  varietie^s  and  species 
I  orrelation  of  jfrowth  soems  Ut  have  plaveil  a  most  im- 
fXirtaiit  part,  so  that  when  one  pan  h;is  i>een  modirte<l 

•ther  parts  are  neceasarily  mudilied.      In  both  varieties 
^..'1(1   species  reversions  to  lon^f-lost   characters  occur 
How  inexpLcable  on  the  theory  of  creation  is  the  o<ca 
^  onal  appearance  of  stri}>es  on  the  shoulder  and  Ie^« 

■r  the  several  s[>ecies  of  the  horse-eenus  and  in  their 
.'iybrids  I  How  simply  is  this  fact  explained  if  we 
'"elieve  that  these  species  have  descende*!  from  a  striped 
,'  ■o^euitor,  in  the  same  manner  su)  the  wver*!  JomeatK 


> 


5v?K5? 


■»4W" 


WW^M^^^Mm^J^^^^- 


4?« 


ON     rHK    (>KI(;iN    OK    M'KC  IKS 


5  f 


hr»'«''l-  of  pi;r»c)i,  hiivo  (losccnfi»'»l  from  'lii>  Mii»'  ind 
!iarr»'»J  ro,  k-pi'jpor)  ' 

<  >n  tlit»  (trfliii.'irv  view  ot  ♦'ach  s|i««cu'-  lia\iiij.'  l>f«'ii 
iii(U'i>''ri(ipntly  iTf-atcd,  why  -hould  Uu*  sjM'cifii-  clinrar- 
t«'r'«.  or  tlu>se  hy  winch  the  »|>t*rien  of  the  sanip  t'emiN 
rliHcr  frnni  e;ich  ulhor,  Ik*  more  variaMo  tlian  the 
^■eiu'ric  el;  ira<;t«rn  in  whirh  tli«^y  .ill  aijree ;  ^^  hv,  for 
in<t;in(  •',  should  tlie  colour  of  a  flower  Im»  more  likely 
to  \:ir\  ;ri  any  one  wperievi  of  a  treiius,  if  the  otlier 
H}).  'P'i,  sint]>ose«l  to  have  heen  creiit*«l  iiide|»eii(leiitly, 
havB  dirifereiitly  coloured  flowers,  than  if  all  the  >i|>erieH 
of  the  i:eriii»  have  the  name  coloured  flowern  .^  If  speries 
are  only  well-inarke<l  varieties,  of  which  the  characters 
have  l>ec(>me  in  a  hi^rh  deji^ree  i>ermanent,  we  i.an 
mider«taiid  this  fact  ;  for  they  have  alreailv  varied 
"tince  thev  hranche<l  off  from  a  common  pro^j^enilor 
iu  certain  characters,  hy  which  they  have  come  to  he 
sp«'cificallv  distinct  from  each  other  ;  and  therefore 
these  -ame  characters  would  Ke  more  likely  still  to  Ik» 
variahle  than  the  a^eneric  characteni  which  have  Keen 
inherited  without  cliantf»»  for  an  enormou*  [»erio<l.  It 
it  inexjilicahle  on  the  theorv  of  creation  why  a  part 
rievelojHMl  iti  a  verv  unusual  manner  in  any  one  s|>e«-ies 
of  n  <r»'r\us,  and  therefore,  ax  we  may  naturally  infer, 
of  g-reat  importance  to  the  H|)ecies,  should  J»e  eminently 
liahle  to  variation  ;  but,  on  my  view,  this  part  has 
undergone,  since  the  twweral  Bpecies  hranche<i  off  from 
a  common  [irogenitor.  an  unusual  amount  of  variahility 
and  mod'tiiafion,  and  therefore  we  might  expect  this 
part  generally  to  he  still  variable.  Ilut  a  part  may  l>e 
Hevelop'd  in  the  most  unusual  manner,  like  the  wing 
of  a  Iwt,  and  yet  not  be  more  variahle  than  any  other 
Btaucture,  if  the  part  he  common  to  many  8ulM»rdinate 
fonnx.  that  is,  if  it  haa  been  inherited  for  a  very  lonjf 
period  ;  for  in  this  case  it  wil!  have  l^een  rendered 
con-tant  hv  long-c<mtinued  natural  selectifui. 

(ilancuu;  at  instincts.  marveHnu*  ai-  s«)rn«»  nr».  the? 
offer  no  greater  difficulty  than  doe*  corporeal  structure 
on  the  theory  of  tlie  natural  selection  of  successive, 
■liffht,    but    profitable    modirtcationi.       We    ean    thuf 


m^^^^imA 


[{?:(  AIMTI  I.ATION    AM)   (  ()N(  I.l'SK  •%    4-7 

jnd<>rst.i!i<l  wiy  nature  rnuveH  \>y  trailuatrd  8t»«ji<«  in 
(Midiiw  :iitr  (lilffrerit  aniiiialt  nf  ilio  naine  olas!*  with  tli"ir 
-ovcral  iiistiiift)*.  I  lia\f>  attpmjitj'd  tf»  show  Imw  nun  h 
iicht  thf  priricijiU'  of  jfraiiatioii  ihrnwfi  on  th«»  mlmirahle 
ar(lut»'«tiiral  |((>w»»r>*  of  the  hivp-hee.  Haint  no  douht 
HOinctimj'H  ooriips  into  play  in  niodjfvirnf  iifitincf*  ;  hut 
it  (••.-♦aitily  IS  not  in'iistK'iisahle,  aa  we  »e^,  in  tho  «a><o 
of  iieuttT  iii-oct*!,  wliH-h  leavp  no  progeny  to  inherit 
the  effe<t-s  of  loinr-totitiuuod  hahit.  <  hi  the  view  of 
all  the  species  of  the  name  trenuH  liaving  de*<r»'iide(l 
from  a  cornnion  parent,  and  having  inh<-rit»Hl  niinh 
in  <-omniun,  we  <'jin  understand  iiow  it  i<i  tliat  allie<l 
«pe«  u'H,  when  placeil  under  eonsiderahly  different  enn- 
riitions  ot  life,  yet  nhould  follow  nearly  the  K.irne 
instinct*  ;  why  the  thruHh  of  houtli  Amenra,  for 
inntance,  lines  her  nest  with  mud  like  our  British 
«{>ecie«.  Oil  the  view  of  instincts  having  heen  bIowIv 
ii(juire<l  through  natural  selection  we  need  not  marvel 
it  some  instincts  heing  ap{tarently  not  jxirfect  and 
lialile  to  mistakes,  and  at  many  instincts  causing  other 
animals  to  suffer. 

If  species  be  only  well-marked  and  jwrmanent  varie- 
ties, we  can  at  once  see  why  their  crossed  offspring 
should  follow  the  same  complex  laws  in  their  degrees 
and  kinds  of  ret<emhlance  to  their  parents, — in  l»eiug 
aiworljcd  into  each  other  by  successive  crosses,  and  in 
other  such  points, — as  do  the  croHwed  offspring  of 
acknowledged  varieties.  On  the  other  hand,  thet-*' 
^ouid  b«  strange  fact*)  if  species  have  been  inde{>end- 
ently  create<l,  and  varieties  ha^e  been  produced  by 
•^•condary  laws. 

If  we  admit  that  the  geological  record  is  imfienVrt 
in  an  extreme  degree,  tlien  such  fact-*  a^  the  record 
ifives,  8UpjH».-t  the  the<»ry  of  descent  with  moditicatioti 
N'ew  s[>«cies  have  come  on  the  stage  slowly  and  at 
successive  intervals  ;  and  the  amount  of  change,  after 
eijua!  iuterviila  nf  time,  is  widely  different  in  differeiit 
"he  extinction  of  st»«cies  and  of  whole  groui 


ip8. 


'P 


of  s|>ecies,  which  has  pl.iyed  so  conspicuous  a  {»art  in  the 
history  of  the  organic  world,  almost  inevitably  followi 


HI 


i2i^ 


ON   THK   OIIKJIN    OF  yi'K(  Ih> 


III 


■  11  t:  •'  principle  of  iiatur.il  »ol«'<:lii.ii ;  fur  <»1«1  form;*  wili 
t>o  (iup|il:iiitp<l  !))•  ru'W  .-iiiij  improved  torms.  N<Mtln  r 
-iritrit?  -pf  ie.«  nor  Kroup-^  of  •.ppcips  r»>.ipp«".ir  wli^ii  iht> 
(liii.tj  <>t  oniiiiiiry  u'eneration  Jian  once  lireri  liruken. 
riie  trraijiial  ditf  iisioii  of  ilomiiiaiit  form'-,  with  the  hIow 
mi»iiiticaiii»ri  ot"  th«'ir  descen«laiit>j,  cau-cs  the  forniH  nf 
li;f>,  after  ioiitr  intervals  of  time,  to  ap[»ear  lut  if  they 
lia.l  chaiiired  >niiiiltaneou»ly  thron^fhout  the  world, 
i'lii"  fact  of  the  fossil  remauiH  of  each  formation  In-ing 
in  some  lituTce  terrnediate  in  character  hetween  the 
fr)s.sil8  in  the  formation.^  ahove  and  lielow,  18  simply 
""xplained  hv  tlieir  intermediate  position  iu  the  chain 
ot  de.-cent.  The  jfrand  fact  that  .ill  extinct  orjfanic 
ln'intfM  helon^f  to  tlie  same  systeru  witfi  recent  r)einff8, 
tallint;  either  into  the  same  or  into  intermediate  trroup-, 
tollow-t  from  the  liviiitr  ami  the  extinct  benitr  t'u^ 
oti>jprin;f  of  common  parents  A-  tiie  jrroups  which 
have  descended  from  an  ancient  pro;renitor  have  tfener- 
tllv  diverired  in  character,  the  pro^renitnr  witli  its  e^irly 
descendants  will  often  he  intermediate  ii\  character  iti 
■oni|>;irison  with  it,s  later  descendant'^  ;  .ind  thus  v*.- 
can  see  whv  the  more  ancient  a  fossil  is.  the  oftener 
«t:irids  in  some  deirree  intermediate  between  existinu' 
and  allied  groups.  Itecent  forms  are  tc^'H'Tally  looke«l 
i'  A>-  In  iiiL',  in  some  v:i;rue  sense,  higher  than  ancient 
.nd   extinct   forms;    and   thev   are  in  so  tar  hieher  an 

he  later  and  more  improved  forms  liave  conqtuTcd  the 
i.hler  and  less  improved  organic  lK?in>js  in  the  struggle 
Mjr  lif»'.  Ui^tly,  the  law  of  tlie  hmc:  endurance  ol 
lUict  t'nim.^  o.i  tlie  same  continent.  .f  niarsuj)ial!»  in 
Ati<tralia,  of  edciitata  in  America,  and  oth.er  such 
case.s,  —  IS  iiitelli^rihle^   f,,r  within  a  confined  >  uuntry, 

he  recent  and  the  extinct  will  naturally  be  allied 
Ity  descent 

I.ookiii;:'   to   i.'cot;ra[diicai   di-trihution,    if   we   admi* 
tiiat    ihere   h.a.s    heen   dumiif   the   lo:i^'   course  of  a^'es 

7::Ui  n    ITi:;; ;  .iv;'.>i;    i:;;:::    vr::c   p.i:  ■-   •--i    i:;v    -»•_':  m    I'.-  n-: 

owintr  tt>  former  climatal  and  jfeojjraphical  chances 
md  to  the  many  occ;i*ional  and  uuknoHn  means  of 
dispervtl,   then    »»e  can    iindo-.-find,   on   the   theory   oi 


lXT?,\i 


4tfLii 


RKCAPmn^TION  AND   (ONC  Ll'SION   4TJ 


■Icjueiil  with  modification,  nnwt  of  tli«  jrroat  lea<liiu 
fal■^«  III  ni-triliiition.     W  v  can  hee  why  tlit>r»'  hIiohIiI  U 


NO   N 


trikiii?  a  itarcllt'lisin  in  tlie  distriiiutiuii  ot 


ortraiiif 


tw'iies  throu^'liu'Jl  K[»aro,  nii'l   in  thoir  >f«'ol(n:ical  suc- 

'•essioii   throujfliout  time  ;   for  i:i  lioth  oases  the  lioi"i;rH 

have  lK}eri   ronnerted   hy  the  l*oiid  of  ordinary  ifeinTa- 

t  on,   and    tlio  niranii  of  nio«lifi.  atiori   have    i»eeii    the 

•nine        \V  e    -in;    tiio    full    rneaniiitf    of    the    wundcrful 

•n-t,  whirh   must  have  Htruck  every  traveller,  narnelv, 

li;it  on   the  name  continent,  under  the   most  diverse 

iinditionn,   under    heat    and    cold,   on    nioiiiiLiin    ami 

iwland,  on  dosertH  and   mar-hes,  mo-t  of  the  inhabit 

tilts  within  earh  jrreat   tl;i>s   are  plainly   related  ;    fo' 

'hey  'ill   jfenerally   l>e  destendantj^  of  the  same   j>ro 

;.'eiiitorH  and   early  colonistH.      On   thix  name   |irinci|d» 

of   former    mijf ration,    comhined    in    most    ca-ies    witi; 

•nodification,   we   ean    iindersUind,    hy    the   aid   of   the 

•Jlai'ial   jM'rio*!,  the   identity  of  s(»me   few    planti,   and 

he  (hwe  alliance  of  many  others,  «mi   the  most  dutaii* 

•  M  iiitaiiiH,  under  the  most  different  climates  ;  and 
ikewise  the  close  alliance  of  some  of  the  inhabitant-* 
■f   the  sea   in   the   northern   and    southern    temperate 

/ones,    thou^rh    separiiled    hy    the    whole    intertropical 

•  iceau.  Althoin.'h  two  area*  may  present  the  Bame 
physical  conditions  of  life,  we  need  fe«'I  no  surprise  at 
Uieir  inhahitants  heiii)?  widely  different,  if  they  have 
!  '-en  for  a  lonp  period  completely  separated  from  eacli 
other;  for  a:)  the  relation  of  ortranism  t«»  orjranism  is 
l!ie  most  important  of  all  relations,  and  aH  the  two 
ireas  will  have  received  colonist/)  from  sonie  thin! 
-ource  or  from  e;ich  other,  at  various  fieriods  and  in 
'litfereut  proportions,  the  course  of  modification  in  tlie 
*wn  areas  will  inevital)ly  l»e  different. 

<>n  this  view  of  nii^rratiou,  with  suh^e^lllor;t  modifica- 
tion, we  can  see  why  oceanic  islands  Hliould  he  iiihahited 
iiy  ivw  species,  but  of  the>e,  that  many  should  he 
l>eculiar.  We  can  clearly  see  why  those  aninial- 
whuh  cannot  cross  wide  sjaces  of  ocean,  as  fro^'^s 
and  terrestrial  mammals,  phould  uot  inhal'it  fM-eanic 
islands;  and  why,  on  the  other  hand,  new  and  pe.uliar 


m 


M 


^W^^ 


■W" 


'^m^t^mu^ 


4;?f) 


ON    niK    OK  I  (.IN    OK    H1'K<  IK"* 


.|.f«i»-'  of  luitM,  which  rail  traverse  the  ocpaii,  slioiilil 
«(i  ot\rii  he  foiiiul  nil  ixUihIh  f.ir  ili^Uiit  frr)ni  .iii\ 
,  (Uitjii«-!il.  Such  facU  a.H  th«  |)rowMi.«  of  (..».  uli»i 
«iMTU"*  of  hrtlx,  .-iinl  ihp  al«»»'!ii«»  of  all  other  ni.iminalH 
oil  o.  iMiiic  JHlaiult,  ar«»  utterly  in«'xi.lir;ihle  on  lh» 
lli«»<irv  of  iiidrinMidi'iit  a<  ;»  of  <r«'.itioii. 

Th.'  t'xi-t.'ii.  e  of  do-ely  allied  or  rej.resonUtivi 
jiKMii's  ill  aiiv  two  areji-,  iinplu"*,  on  the  thenrr  o 
(i»-»,.»Mil  with  intMliiHMtioM,  LliHl  the  <ime  juri-nt-  for 
merly  iiiliJtt.iu-<l  lM)th  are.-is  .  ami  we  almost  iiivariahli 
fimi  Ihat  wherever  ru.tiiv  clo«ely  allie.l  aperies  inhahi 
two  areas,  somu  loiilital  npecies  iDriimou  t<»  hotli  stil 
«\i-t.  Wherever  many  (•l»»sely  allie.1  yet  <ii<tinc 
Hpei-ies  oiour,  many  douhlful  forms  and  virieties  o 
the  H^nrie  speeies.  likewi>ie  <M-ciir.  It  is  a  rule  of  hij;! 
ffeiierality  that  the  inhahitiiit-  of  each  area  are  relate< 
to  the  inliahitants  of  the  iie.aresl  Hoiino  wheiit-e  iinmi 
^'rantH  mi^ht  have  Ikm-ii  derived.  \Ve  nee  tlii*  ii 
nearly  all  the  plaiitx  and  animals  of  the  (Jalipajjo 
Ar<lnpel;i^'o,  of  Juan  Fernandez,  and  of  the  othe 
Aineriraii  island;,  hcint:  rehitwl  in  tiie  most  strikii)| 
manner  to  the  plants  and  animals  of  the  neiK'lihouriiij 
American  m.iinland  ;  and  th(we  of  lh.>  (ape  de  Verd 
Ar«iii(K'lauo  and  other  African  islands  U)  the  Africa: 
mainl  4inl.  It  must  be  admitted  that  these  fads  re<  eiv 
no  explanation  on  the  theory  of  creation. 

The  fa<-t,  as  we  have  seen,  that  all  iKist  and  pre.^11 
ortfHtiic  Immiic*  constitute  one  -rraiid  natural  system 
with  tfroup  sulM»rdiiiate  to  trroup,  ami  with  extint 
firroups  otteii  falling  in  hetwe»>n  recent  groups,  is  it 
terniril>io  on  the  theory  of  natural  selei  tioii  with  il 
ct>ntii.;,'enoies  of  extinction  and  divergence  of  chai 
acter.  On  these  siime  principles  we  ^'e  how  it  ii 
that  the  mutual  .itrmities  of  the  species  and  tfeiiei 
within  each  c!:i«s  .ire  so  complex  and  circuitous.  W 
see  why  certain  characters  are  far  more  serviceahl 
than  others  for  cl;issifi.  ation  ;  -  why  adaptive  cha 
ictcr-,  thoiitrh  of  (.aramount  importiiue  to  The  i.euu 
are  of  hardly  .tiiy  import-'ince  in  classiti<ati«»n  ;  wh 
ch.ir.Ktcrs  derived   from   rudimenta-y  jiart-^.  liiou^'h  1 


if^!K^ 


"^ 


m^^smi^ 


m:^ 


RK4  AIMTCLATION    AND   COM  U'SfON    4.-]l 

ho  M"-\ii»j  Ui  the  lK«iinf,  are  often  of  hiifli  c  la>wif;ratiirv 
».»iii«';  ;»ti<l  wliv  erntir\  iilnj^'.-.i!  characfiTs  .irt*  tlie  trm^i 
.itiii,il>l»«  <•»  all.  Tiie  real  aJftintien  of  all  urifaiiii  Kt'iinfs 
at>'  line  t«»  iiihcrititiife  or  roiiimufiity  «»f  «l(wi«.nf  The 
iiitiiral  t»v>.ti«n)  m  n  t'l-iM-aJoL'tial  arraiufPiiu-nt.  in  v*liirh 
*f  have  »M  iliscnvfr  tht<  Iiium  ot  (i«««i  ••iit  l>\  tlu'  tiuwl 
fn'rrnain'iit  ilianwUirh,  however  -Ii!;!!!  th«'ir  vif.tl  iin- 
I'orUi.f  e  riiav  \>vi. 

l'}io  Iraiiifwork  of  iMH.fs  hfiiiir  th..  ^^itiie  iii  tii»*  h.uiii 
ot  a  rnaii,  wiii;;  of  a  l>at,  fin  of  the  {Ktrpoisr,  and  li-^'  of 
tli»«  hor-f.  the  •i.ttni'  nn  nht»r  of  \«'rt«>lirii«  fi'riiii:,^;-  th»» 
iiHik  of  the  jfirifif  ami  cf  tlie  el.'pliaiit,  ami  iniiurner 
a'lje  (ither  H\uh  fa.tjt,  at  onre  explain  tii«'rn.m>lM^  on 
tiip  tfio<try  of  (Jo-.!  f  nt  witli  nlnw  and  slijrlit  «in(  t'4«ivc 
iMi»difioat  oi'H.  'I'h««  .^uiularity  of  pattt-ru  in  tiif  winjf 
i\ui\  Icif  of  a  hat,  though  ii^ed  for  hucIi  ditformt 
('iiriwi>«',  — in  the  jaws  and  1«'4.'h  of  a  crah,  —  in  the 
|M'i;iN,  stameuM,  and  plstiU  of  a  flower,  \»  likewise 
int»'llit:il>le  on  the  view  of  tho  tfrad'ial  moditi.ation 
ot  partri  or  orjfan-*,  whii  li  wi-re  alike  in  the  e-iirly 
prui^iMiitor  of  eavh  flans.  ( )ii  the  prinriple  <if  stuN-e*- 
«ivo  vari.ifimH  ni»t  always  superveniiitr  at  an  Marlv 
.i:rp,  and  ht'inir  inherited  at  a  corre.sjxniili.Mir  not  early 
p«'rio(l  of  life,  we  oan  clearly  )*ee  why  the  eiiihryoh 
i>f  mainmalu,  hinls,  reptiles,  and  fishes  xliould  U>  no 
tlo»ely  alike,  and  should  l>e  so  unlike  the  adult  forms. 
\N  e  may  iea<.e  niarvellirnf  at  the  emhryo  of  an  air- 
hr«vithin>f  mammal  or  hird  havjnir  hraiuhial  slit.s  and 
artt-ries  runninjf  in  loops,  like  iho.^e  in  a  fi>h  whii  h 
h;w  to  hreathe  the  air  dirisolved  in  water,  by  the  aid  of 
well -developed  hran«hi>e. 

Disuse,  aided  .•.nfoftimi's  l;y  natural  selertion,  will 
often  lend  to  reduce  an  or^an,  when  it  ha.s  ln-inrnM 
useless  Ity  rliaiitfed  hahit«  or  under  rhaiiifed  conditions 
of  lite;  and  »»•  can  clearly  undj-rstand  on  thi-^  vifw  the 
meaumir  of  rudimentary  orfan.s.  Wat  disus«'  and  s^lfc- 
lion  will  trenerally  act  on  each  creature,  when  '<i  !ia< 
"•'^r.c  kO  t!;awurity  ann  h^-^  ro  piav  it.s  iuii  ji.n  l  m  Ui*? 
otnijrtrle  for  e.xistence,  and  will  ilius  have  li:tl»'  jH)v»er 
"f    u.tin::   or;   an  urjran   during   earlv   life;    hence    the 


43S 


ON   THE   ORUilN  OF   SPECIES 


i  ) 


orga^u  will  not  !><»  much  reduced  or  rondorod  rudi 
nieiitary  at  tliis  early  hucp.  'I'he  calf,  tor  instance,  La.- 
inheritfil  teeth,  wliich  never  cut  throuirh  the  gums  o: 
the  ujipcr  jaw,  from  an  early  progenitor  havinir  well 
develn|i»Ml  teeth  ;  and  we  may  Wlieve,  that  the  t«etli 
in  the  mature  animal  were  reduced,  duriuir  yucre>;siv< 
ironerations,  hy  disu-o  or  hy  the  tongue  and  i>alatt 
liavin::  Ihmmi  better  titled  hy  natural  selection  to  l>rows( 
witliout  ilioir  aid  ;  whereas  in  the  calf,  the  teeth  have 
lieen  led  uiito'iched  liy  selection  or  disuse,  and  on  tlif 
priinijile  of  inheritiuice  at  corresjKindinff  a^^e-  havt 
Ueeii  inherited  from  a  remote  perimi  to  the  present 
day.  On  tlie  viev*  of  each  or^'nnic  heiri^  and  each 
separate  or<,'an  havintf  l>een  specially  created,  how 
utterly  inexplicahle  it  is  that  j>art«,  like  the  teeth  iu 
the  embryonic  calf  or  like  the  slirivelled  winps  under 
the  soldered  winjr-covers  of  some  beetles,  HhouM  thu:< 
so  freciuently  War  the  plain  stamp  of  inutility!  Nature 
may  bo  said  to  have  taken  pains  to  reveal,  by  rudi- 
mentary or^rans  niid  hy  homologous  structure,  her 
scheme  of  modihcation,  which  it  seems  that  we  wilfully 
will  not  understiind. 


1  have  now  recapitulated  tlie  chief  fact**  and  con- 
dideralious  which  have  thoroug^hly  convinced  me  that 
species  have  l»een  moditied,  durin^j  a  lon^  course  of 
lescent,  by  the  preservatitui  or  the  natural  selection  of 
many  successive  slight  favouralde  variations.  J  cannot 
believe  that  a  false  theory  would  explain,  as  it  «eems  to 
me  that  the  ilieorv  of  natural  selection  does  explain, 
the  "icveral  larjfe  cIaK>es  of  fact*  above  specitied.  1  st'e 
no  ^ood  reason  wliy  the  views  jfiven  in  this  volume 
should  shock  tlie  religious  feelings  of  any  one.  A 
celebrated  author  and  divine  has  writteu  to  me  that 
'he  h-is  trradually  learnt  to  see  tha*  it  is  ju.-st  as  noble 
a  conception  of  the  Deity  to  believe  that  He  created 
a  few  oritfina.  forms  ca{table  of  self-«levelopment  into 
other  and  needful  forms,  as  to  lielieve  that  He  required 
a  fresh  act  of  creation  to  supply  the  voids  caused  by 
*he  action  of  His  laws.' 


RE(  APirrr^TioN  and  (oncllsion  m 

\^l.y.  it   may  \Hi  aske.l,  have  all   th<.  most  emii.e.it 
I'VMi-  i.aturalivK   and   frool„irist^  r.>j<M-t(vl   thi^  view  of 
^he  n.ut..I.ility  of  s|, erics  ?     Jt  rai.iiot  \>e  asM-rted  that 
Tt-a.Mc    l.e.n^fs    in    a    stite    of  nature   are   si,I.j,.,-t    t.. 
•o   variation;    it   cannot   be   proved    that    the  amount 
"f  variation    ...   the   rourse   of   lon^   ace.   is  a   limited 
'^'aut.ty;    „„   .-h-ar   distinction    has   heen,  or   can    he 
.  rawn   l-et^v,.,-!.   species  and  vM«l]-markod  varieties       It 
.ii.not  he    n.ai.itainod   that  f=pe,ie8  when   intercrossed 
^re  invanahiv  sterile,  and   vanHies  invariahlv  fertih.  • 
or  that   st.;nl.tv   is   a   s,,e<ial   endowment  and   sitwi   oi 
.^reation.      1  he  In^hef  that  species  were  imm.it.-.hle  pro- 
...u:t..,ns  was  almost  unavoidahlc  as  lon^  a.s  the  history 
"t  tne  worl.i  was  thoudit  to  he  of  short  duration  ;  a.id 
MOW  that  we  have  ac.juired  some  idea  of  the  lapse  of 
tm.e.  we  are  too  apt  to  assume,  without  proof,  that  the 
.-olo^ncal    recor      is    so    ,H;rfect    that    it    would    Kave 
atiurded    UK  plai.      vwlence  of  the  mutation  of  sm-cies, 
■  tliey  had  underjrone  muti*' m. 

IJut  the  chief  cause  of  our  natural  unwillin-ness  to 
Hnut  that  one  sjK^-cies  ha«  ^iven  hirth  to  other  and 
<:ot.nct  species,  is  that  we  are  always  slow  in  admittintr 
u.y  preat  chanire  of  which  we  .lo  not  see  the  interme 
':!ate  steps.  The  difficulty  is  the  same  as  that  felt  hy 
;..  ma.y- jrooh.^ists,  when  I.yell  rtrst  insisted  that  lonjf 
nnes  of  ...land  cliffs  had  heen  formed,  and  ^reat  valleys 
.^xc-vated.  hy  the  slow  action  of  the  .-oast-waves  ^e 
'""i'l  nninot  possihly  ^^rasp  the  full  mwinii.^r  „f  the 
uT.n  Of  a  hu.idred  million  years;  it  cannot  add  un 
••>i'l  perceive  tne  full  effects  of  many  slight  varia- 
t:ni:s.  accumulated  during  an  almost  infinite  numlM>r 
<jf  t:irieratiOTis. 

Aithoucrh    I  am  fully  convinced  of  the  truth  of  tl 

^py-  tiivou    iu   this    volume    under    the    form    of  ?.. 

■"•stract,  I  by  no  means  expect  to  convince  experienced 

•H  'iiali.ts  whose  nunds  are  stocked  with  a  multitude 

'"  f.trt^  all  vieued,  durinjr  a  Io.ik  course  of  years,  fn.m 

;     .     .  ,  ..,^  ii:.vi.uy  opposite  ii.  iiiiiie.      it  is  so  easy 

'.»"de«Mir  ijmorance  under  such  expressions  as  the 

P -«n  of  creation,'  '  unity  of  design.'  etc, ,  and  to  think 

2  k 


w^K^^mrm 


4.^4 


ON  TUF-:  ORIGIN  OK  spe(if:s 


that  «<•  iriv  •>  an  exi.l.iiiatinn  w1i»mi  we  only  restate  a  farl 
Any  iim>  wli«.-«'  disposition  U\tiU  liiin  to  att.uli  nmr 
wtML'lit  to  urifxplained  ditfirulties  tli.m  to  the  fxplan: 
ti.tti  of  a  certaii  iiuinhor  of  facta  will  certainly  reje« 
rnv  lli'-orv.  A  few  natiirali-ts.  endowed  «itK  niuc 
(Ic'xihility'of  mind,  and  who  have  already  hefiin  t 
donht  on'  the  iiiimiitahility  of  species,  may  he  influence 
}■:■  tins  volume;  Int  I  look  -^ith  contidence  to  the  futiin 
to  vonn::  and  risin-r  natnrali>ts.  who  will  he  a'de  1 
\  lew  hoih  sides  of  the  «|iiestion  with  impartiality.  W  \u 
e.er  is  led  to  helieve  that  species  are  mntalde  will  < 
tood  service  hv  conscientioiislv  expres»inir  his  convi 
ti.-M  ;  li»-  oiilv  thu>^  can  the  load  of  |»reiu«iice  hv  whit 
this  siiiiject  is  overwhelmed  l»e  remo\ed. 

Several   eminent  tiatiinili>ts   have  of  late   piihlisht 

their  helief  that  a  multitude  of  reputed  -pedes  in  ea« 

tienus  are  not  real   cp,.,-ies  ;  hut  that  other  species  a 

real,  thai   i«,  have   heeii   iiidejiendently  created.      'Hi 

<eeins   to   me  a  stranirP  com  lusion   to  arrive  at.       ITii 

a. i lint    thai    a    multitude   of   forms,   which    till    late 

they   themselves   thou^Mit  were  r-pecia!    creations,   at 

winch  are  still  thu-  loi>ked  at  hy  the  mai«irity  of  nat 

rali>ts,  nnd    which    consequently    have   every   e.vtern 

characteristic  feature  of  true  species.— they  admit  th 

these  ha\e  U'en  produced  hy  variatioJi,  hut  they  refu 

to   extend    the  sjime   view   to   other  and   very  sliirht 

ditferent  forms.      Nevertheless  they  do  not  pretend  th 

thev    can    dehne.   or   even    conjecture,    which   are   t 

created  forms  of  life,  and  which  are  tho-e  produced 

secondary  laws.      They  arlmit  variation  as  a  ivm  rah 

in  (uie  case,  thc\  arl»itrarily  reject  it  in  another,  witho 

as>iw-iiiii:r  any  di-tin.tion  in  the  two  ca-e^        The  d.ay  w 

r(»!iie  wheti  this  will  Iw  triven  as  acurious  illustration 

the  hli?ldne•.^  of  precoiu  eived  opinitm.      'llie-e  authf 

veem  no  more  startled  :\i  a  mira<-ul(Mis  act  of  creati 

than  at  an  ordinary  Idrtli        lUit  do  they  really  helie 

lli.it    at    iiinuniera\>le    iieriod*     in    the    earths    histo 

certain  eiemenlai    alorii!»    iiave    tx-en   comma. mcu     vv 

denlvto  flash  itito  livitiir  tissues?'     Do  tliey  l.elieve  tl 

at  each  supposed  ail  of  creation  one  uidiMdual  or  ma 


"/J^i 


^ 


M^w. 


.^'. 


IP 


mm 


KKCAIMTLLATIOV   AVD  (ONC  LISION    4-''A 

wfTf    |iro<lii(»H]  .-       W'cTf    ail    i\ 

kind- 


'<r  H 


le    intinitolv    nurnrn.im 
of   anm.als   ami   plants  inMtt-.l   as  e-j^^  „r  , i^ 

m;irnin;i!v.   m«re 


I.-    full 


trn.nn.-  and   in    tlie  ca-e  nf 


•t.ey  fmitf.i  Uviriiiir  the  fal-o  marks  ,.i  liuuri.hn.ent 
tn.m  the  rnotlifr's  w„inl,  -  Althoii-h  naturalist-  *Prv 
pro^HTly  i]('uuiu,l  a  fuli  exi.lanation  ot  i-vitv  .iah.-ulty 
ri..rn  tli..-..  wh.,  l.^lievo  in  the  mut.-.h.htv  ..t  sj.erics,  on 
•Ii«':r  „An  ^uh>  the;.  i;rnorH  the  whole  suhi.-.  t  ..(  ♦'le  lirst 
i|'I>earan.-e  of  spenes  i;,  « hat  th.'v  con-idcr  re>erent 
^'leiue. 

It  may  he  asked  h(.M-  f:ir  /  extend  the  dc.ctrine  i.f  the 
'no.;if,cation  of  species.  The  .iue>t...n  is  d.lh.iilt  U) 
.iiiswer.  he.  auso  the  more  distin.-t  the  forms  are  whirh 
>^(•  may  <-(.asider,  hy  so  mueh  the  ariruriients  fail    iwav 

n  for.-e.      fJut  some  arjruriients  of  the  greatest  wi-i-h't 
'■xtend  very  far.      All  the  rnemhers  ot  whole  classes  ean 

"•■  •■'"" '•"''    to^'ether  hy  chains  .,f  athn.ties,  and    all 

'  ui  Ik.- <  lawsitied  on  the  same  principle,  in  groups  suh- 
-ruinate  to  >f  roups.  Fossil  remains  sometinies  teml  to 
till  up  very  wide  intervals  hetween  existuitr  orders 
<  »r:rans  in  a  rudimentary  condition  plainly  &h.nv  that  an 
'••irl;  .rotrenitor  had  the  or^^an  in  a  fullv  developed 
-•  ite  ;  and  this  in  some  instances  neviis-sanl'v  implies  an 
•normous  amount  of  moditication  in  the  dowen.lant^ 
InroujrlM.ut  whole  cla.s.ses  various  structures  are  formed 
"ii  the  same  {ttttern,  and  at  an  emhrvouic  a^e  the 
"[•ecies  closely  rpvemhle  each  other.      Th'erefMre  i   can- 

nt  duuht  that  the  theorv  «.f  descent  with  modification 
■  ■■nhnices  all  the  menihers  of  the  smie  daxs.  I  lK?lieve 
that  animahs  have  descended  from  at  most  only  four 
'T  five  pr..^enitors.  and  plants  from  an  equal  or'les.M.r 
iiiirnher. 

Analoiry  would  lead  me  one  step  further,  namely,  to 
•!.'•  t>eliet  that  all  animals  an.l  plants  have  de-'ended 
•inr„  some  one  prototype.  Hut  analojrv  may  t,e  a  de- 
ceitful irui.le.     Nevertheless  all  livin^^  th'in^s  have  much 

.!!  common,  in  theirchemicalcompo.iti<.n.  their  germinal 
•  t-:y.  ic.s,tiie;rr,--iiuiax  structure, and  tiieir  iav\s.it  t-^-oHth 
ind  rcpro.lucliori.  We  see  this  even  in  ^^o  triflinir  a 
nrcuiustance  a.«  that   the  K.-in,e   poison  ot\en   similarly 


I 


436 


ON   THE   OKKJIN   OF  SPEC  IKS 


,1-.. 


atff(t>  j.laiit-  .iiLi  animal-  :  nr  tint  tlic  poison  flCcrffO 
i.V  tlip  tralMlv  j>r()(liii'<'«  m(.iistiiii;>i  i:rHi\tli«i  on  tlie 
vv'ild  n.-e  <ir  nak-trcp.  I'hen'fore  I  slioiil'i  ii'f.T  froir 
aiialotrytliat  |)rohal)lv  all  the  ortfanio  liein^s  wliirli  liav» 
rvor  liviMi  nil  tliin  <-artli  have  (lom-Piulwl  from  >Mino  «>i>« 
primonli.il  form .  iiitn  wiii.  li  liU'  wa.«"  first  hrcatlanl  h\ 
•hi'  (  real  or. 

\\  ln'!i    tin-  views  advanced    hy   int'   in    tins   volunu' 

an.i    l.\    Mr.   Wallace   in  the   l.inumn  Jmirunl,  or  whoi 

nnalo^roiis  views  on  the  ori^nn  of  specio  are  L'c;icrall; 

a(imitt»>(l,  we  can  dimly  fore>ee  that  there  will  Im'  a  con 

^ide^al.le  revolution   in   na*'iral    history.      S\meniati-t 

will  he  al.lo  to  piirstie  their  lahours  as  at  pro<ent  ;   hu 

tiiey  will   not  he  incess-intly   hauii;c<l   by  the  shadow 

lou'ht  whether  thi-  or  that  form  !•«  in  eoence  a  ^pe.icj 

This  1  feel  sure,  and    I   speak  after  experience,  will   h 

rjo  slifrht  relief.      I'he  endlos  disputes  whether  or  no 

some  fitly  si>ecies  of  British  hraml.lesj  are  true  specie 

will   cease.      Svstematists  will   have  only  to  de< Me  (u< 

that  this  will  he  ea.'sv)  whether  atiy  form  i.e  suiiicienll 

rotistaut  and  distinct   from  other  forms,  to  l)e  capahl 

wf  definition  :  and  if  definahle,  whether  the  ditTerenc< 

1k!  sufficientlv  im|)ortant  to  deserve  a  spetitic  nami 

J'his  latter  poi/it  will   Inicome  a  far  more  essential  coi 

gideration   than   it  in  at  present;  for  dilierences  ^lov 

ever  slidit.  heiween  any  two  forms,  if  not  hlended   \ 

intermediate  L-radations]  are  l(»oked  at  hy  tn<»>t  n.itura 

ipt.s  as   sutVicient   to    raise   both    forms   to  the   rank  ( 

-pecies.      Hereafter  we  sliall   be  comjtelled   to  ackno^ 

led::*?   that    the   onlv   di  tinction    heiween   species   ai 

well-marked   varieties   is,   that    the   latter   are    ivnow: 

<ir  believed,  to  be  connected  at  the  present  day  by  r 

t.Tiuediate  trra.lation-.   whereas  sp.  .ies  were  t..rmer 

thus   eonnected.      Hence,    without   rejectinff   th.-   co 

-i.leration  of  the  present  existence  of  interme<liate  trr 

.iaiions  between  anv  two  forms,  we  shall  l>e  led  to  weij 

more  cirelullv  and    to  value  hijrhor  the  actual   amou 

of  ditierence  between    them.      It  is  .juite   possible   th 

fornw  now  ^M-nerallv  ackiu)wledircd  to  be  mer<"' v  vaneti 


^^mm:'ii^'^^?m^rm^?^kf:r^^. 


T- 


IMM'- 


'r"- '"n^'' . ■  '^ .jlfaJwv    -. 'Jv 


w 


KKCAPirrLATlOV    AND   (()N(  LfSlON    4,17 

ni.iy  lit-reafter  l>e  tliouirht  worthy  of  specific  names, 
18  v»ith  the  primrose  and  cowslip;  ami  in  this  ca.Mj 
■-rientifif  and  common  lantruaife  will  come  into  acronl- 
aiicp.  In  short,  wo  .>.liall  have  to  treat  «ijM'tie«  in  th.» 
-ani»H  manner  as  those  iiatnralistM  treat  jrenera,  who 
aiiiiiit  tliat  jfenera  are  merely  artificial  c<»mhinatioiM 
mad*'  for  convenienro.  This  may  not  \te  a  ch»-eriii.' 
[>rr>.<pect  ;   hut  we  >.h;ill  at  least  i>e  free*!   from  the  «aiji 

•arch  for  the  undiscovered  and  undiscovoratde  eN>»-u.  e 

f  tl''  ti'rm  S'pt'cies. 
ri.e  other  and  m<»rt'  general  dcpartn.cnts  of  natural 
!ii^tury  will  ri>e  yreatiy  in  interest.  Hie  tern  -  used  i'" 
naturalists  (»f affinity,  relationship,  community  of  typf , 
jiaternity,  morphology,  adaptive  characters,  r  mil  mentarv 
:in(!  ai.orted  ortrans,  etc.,  will  ceiLse  to  be  metaphoricaf, 
iM(i  will  have  a  plain  sijfnificatinii.  When  we  no  lonj^er 
iiMik  at  an  ori;anic  hein^ras  a  .^ava^e  hioks  at  a  ship,  a.s  at 
somethinjif  wholly  beyond  his  comprehension  ;  when  wv 
rt'irard  every  production  of  nature  an  cue  which  has  had 
1  history;  when  we  contemplate  every  complex  stnictur** 
liiii  instinct  as  tiie  summing  up  of  many  coutrivances, 
t-ach  useful  to  the  possessor,  nearly  in  the  same  way  aa 
>;'ien  we  look  at  any  ^^reat  mechanical  invention  ;i.s  the 
-Illuming  up  of  the  labour,  the  experience,  the  reason. 
and  even  the  blunders  of  numerous  workmen  ;  when  wr 
•Jius  view  each  orj^^auic  btin^',  how  far  more  interc-tint; 
i  «[n'ak  Irom  exj»orience,  will  the  study  of  iiatura. 
hi>'<.ry  become  I 

A  frrand  and  almost  untrodden   tield  of  inquiry  will 

be  opened,  on  the  causes  and  laws  of  variation,  on  corre- 

liiHi  of  ffrowth,  on   the  et!ect«  of  use  and  di.suse,on 

■he  direct  action  of  external   condilioiis,  and  so  forth 

I  he  stiniy  of  doiiu^tic  productions  will  ri-e  immense^ 

u  value       A  new  variety  rai-cd  by  man  wili  ti»'  a  mori- 

:nportant   and   intereslin^'   subject  for  study   than  oiu- 

more  specie-  adiled   to    the    infinitude  of  already    re- 

"!'!''d  apec!!'-.     Our  rhi^sific.-ttiona  iiill  c==nie  '•'>t>e,a- 

:ur  as  they  can  be  so  mad*',  t;»"iealo^,Mes  ;  and  will  tlieii 

*ruly  yive  what  may  be  calied  the    plan    uf  creation. 

n,e  rules  for  classifyiritr  will  no  doubt   become  •impicr 


I 


n 


♦II 


♦<f-    vS»rC 


1^~7 


^ 


.(jML,.  -i;' 


am- 


m- 


-i--'^' 


■^'    "Av 


i38 


ON    IHK    OKKiJN   ()!•    S|'K(  IKS 


N' 


Ti 
■■■A 

s 
i 


*ii«'H  wo  lia\c;i  ilrtiiiite  (ilijju't  in  vit'w.  W  f>  po^^.e— '  lui 
|>«xliu'r»'<'->  or  ariiiiirial  l-firiii:;-*  ;  ami  we  liavf  to  iVm- 
I'Mvcr  and  trace  tlic  rii.iiiy  iliv t-r^iii;;  liiuM  of  (lf~<«'tit  in 
our  natural  t;t'iiiMlii_n»-i,  by  cliaraftwrs  nf'.in  v  kitui  wliicli 
Ki'.  e  lori::  ln-cn  iiiherittvi.  Kuilimentarv  orj^.ins  ^^lll 
f.[M>ak  iiilallii'ly  wi'Ji  rfsj.ect  to  tJie  nature  ot  lon^r-iost 
xlniituri'^.  >jn'cie«  rii,ii  trrouM-  of  s|M>r  i  »,  wlijrli  art 
caili  il  .iiM'rrant,  imm  wiiiili  :iia\  f'anci;  illy  In*  call.-il 
living  lo^-ii-,  will  aiii  MS  in  lumiinir  a  pH'tnrc  <>t  the 
.in«'i«'nt  J'lirrns  of  lii'c.  I!nil'r\  <i!'>.  \-  will  re^t-al  to  ti<  tin 
>trin  tiirc.  Ml  •^oMio  'ii't-Tt'e  <)l..^i'iici!.  Ill  the  [iroto!  \  pf>  ui 
eiich  j^ri'at  ('.i.^m. 

\\  lifii  w,'  iMii  If, I  a«Mir»>(l  tliat  ali  tlie  indi^  iiiiiiU  ol 
tlu'  s.inH»  -[iiM-,c-,  ami  all  tin-  clo-^-Iy  all;»'<i  -^pei  !0>:  ol 
iM<i-t  tfmra,  nave  within  a  not  \erv  reninte  perod 
de^'  ended  iroin  one  parent  .and  liav»>  initrraleil  frotn  >onit 
one  iiirtlip  i<e  ;  iml  \\  In-n  we  i'«,'tter  know  tli*-  manv 
means  of  lo  liratioii,  then,  liv  tins  i!;.'h*  whieli  tieolotry 
no^  throw-,  and  mil  eon'inwe  to  throw,  on  foriuei 
«lian:;es  of «  lim.ite  and  of  tli«»  level  of  the  land,  v»»'  »hall 
rtiireiy  he  enahled  to  tra<  e  in  an  adinirahU*  inaniier  tin 
former  iiiitfration^  of  the  inhaliitantn  ot  the  w  hole  world. 
Kveii  Hi  present,  hy  ••om[>arinir  the  ditfereines  of  tlit^ 
iiihihitantH  of  llio  «ea  on  tho  opposite  sides  of  a 
continent,  ami  the  nature  «>f  the  various  inhahitantji 
oftliit  ettutinent  in  relation  to  tlo-ir  apparent  niean« 
of  iiniiiitrration,  M)iiie  liyht  i-an  he  llirowii  on  anrieni 
;feo;^r;ijdiy 

'lie  iiohle  scieino  of  (ieolotrv  loses  jrlory  fifim  tht; 
exreiue  iiiiperfeition  t»f  tho  record.  The  crust  of  the 
Kirth  with  its  emU'ddeil  remains  n  ust  not  he  Umked  at 
a«  a  '.wll-til!e<i  rtni-eiini,  hut  is  a  poor  lolle  tion  made 
at  ha/ard  and  at  rare  interval.  The  accurnulatmn  ol 
ei4h  irreat  fossiliferous  formation  will  !>e  rroo;rni.sed  >u 
having  depended  un  an  unusual  concurrence  of  circum- 
hi.iiKes,  and  tiie  blank  intervals  between  the  successive 
siaj:es  IS  havintr  heen  of  va«t  duration.  Hut  vre  -hall 
t>«  at.ie  to  trance  «*ith  -ome  -^i  urity  the  iluration  ol 
t!ie--»'  inter\al>  hy  a  compari.-on  i>f  the  precediiijf  and 
lucccediii^  ur^^auic  forms.       We  must  be  cautious  lu 


V    ■ 


RK(  AIMTI  LATION    AND   (ONdXSlON    439 


ittt-iiijif iiijf  to  correl.ite  as  strictly  coritemporant'ou'* 
'«()  /(iriii.itioiis,  which  iinlude  few  ideiilual  s|>t'i  ii«s, 
l>y  tlie  k't'iienl  sucrt'ssion  of  thcnr  foiius  ot'  lit»v  As 
^l"*"!  .e*  .ire  |.ri>'lini'»l  .nui  exleniuuat«'«l  by  slowly 
:i<li';tr  i'liil  Mill  »"\i-tiii;.'  lausi-,  Jiiid  not  l»y  mirafuloiis 
:i<  ;■»  ut  t  rtMlioii  ami  liy  caUstrui.lit's  ;  ami  a.-,  tlie  iiio>t 
iiHjportaiit  ot  all  rau-x's  of  urj_^:i!iu'  iliaii-**  is  oin»  wiiuli 
i>i  almost  iiKh'peiulent  of  alten-il  ami  j»«Tli.ips  sinMciily 
iltcred  jiliysical  loiidititiiis,  naiiiolv,  t}i«'  mutual  rt'iatioii 
of  (I I  ij- 11:1, in  toortranism,  -  tlu*  ni[iro\»'(n»Tit  of  om*  l>«'ini.' 
<  it.iiliii^  tlie  iiiiprovciiuMit  or  llio  exterminati.iij  of 
oilivrs  ;  it  follow^,  that  tlu"  amount  of  (*ri.^iiiitrli;tn;.M'  in 
llie  fi)~.>.;l»  ot  coii>t'«Miti\e  formations  [iroliahiv  >.t'rvt'>  ,i:<  a 
fair  m«'a>nre  of  the  laji-<e  ot  a»-tual  time.  A  numlitT  of 
-pecifs,  lioai'ver,  kerjiiti:.''  lu  a  Ixiily  iniirlit  r»'main  .'nra 
loMjr  jK'iio.l  umhaiiifcd,  vvlalst  «itiiin  this  sjimei  |.»'riotl, 
-••^ir.il  (»l  fln'>e  sjH'cn-s,  liy  miiiratiii;;  into  new  countries 
a;ici  I  oinin:^  into  com[H.'titioii  willi  forciirn  a>><»ciate'<, 
nii^lit  l>«coine  imMliticil  ;  «.o  that  w»',  mii>l  not  o\crrate 
liic  acruracv  of  oriranic  cliaiiire  as  a  mea.sure  of  timo. 
iMiriniT  early  periods  of  the  earth's  hi^tory,  when  the 
torms  (»f  life  ^e^e  prohahly  tewer  and  simpler,  the  rate 
of  chatii^e  was  prol.ai.Iy  slower  ;  and  at  the  first  davui 
of  life,  i^heii  very  te^*  forms  of  the  simplest  structure 
exi>ted,  the  rate  of  chani:e  may  have  U-en  slow  in  an 
extreme  detiree.  The  whole  hi^torv  nf  the  world, 
as  at  p:f»-ent  knuHii,  aliliun^h  of  a  length  quite  in- 
comprehensible hy  us,  \»ill  hereafter  he  reco^rnised 
as  a  mere  fra^nn-nt  of  time,  coin|)ared  with  the  a^fes 
*inch  have  elapsed  since  tlie  first  creature,  the  pro- 
irenitor  of  iiniumerahle  extinct  and  living  dc-c<  udanLs, 
was  cr«'.ited. 

In  ;h«  ilisUnit  future  I  see  oja-n  fields  for  far  more 
important  re<earclies.  I'sycholotry  will  lie  Iwsetl  on  a 
new  foundation,  that  of  the  necessiiry  ac<juirement  of 
each  mental  power  and  ca|>acity  hy  ^radati«in.  Li;;ht 
will  he  thrown  on  the  oritfin  of  man  and  his  hititorv. 

Auttiors  of  the  hi^liost  eminence  »e*Mn  t«i  1*  fully 
siitisfie<i  with  the  view  that  each  species  ha^  l>een  inde- 
l-endently  created.     To  my  mind  it  accords  better  wjth 


I 


440 


ON   TIIK   ()UI(;iN   OK   S|'E(  IKS 


^11 


ti 


wliat  we  know  ut  the  lawK  iiii pressed  on  matter  hy  the 
(  reator,  that  the  {iroductioti  and  extinction  of  the  p.'ij.t 
and  (iresent  inhahiUnt.4  of  the  wurhl  >houhl  iiave  heeii 
due  to  secondary  causes,  like  tho^e  deterniinin;?  the 
hirth  a!i<l  death  of  the  individual,  When  1  vie-.v  all 
hi'injifs  not  a-  special  creations,  hut  as  tlie  lineal  descend- 
ants of  some  tew  bein:rs  which  li\  ed  loiitf  hefore  the  lifst 
lied  of  the  Silurian  system  wa**  depo.-ited,  they  neem  to 
me  to  hecome  ennohled.  Judyintf  Irotu  the  past,  we  may 
safely  infer  that  not  one  living  species  will  transnnt 
its  unaltered  likeness  to  a  distant  futurity.  And  of  the 
^pecle.s  now  In  in^r  very  few  will  transmit  proj^eny  of 
any  kind  to  a  far  disL'itit  futurity  ;  for  tiie  manner  iu 
winch  all  or;r^nic  hciiiirs  are  ^^rouped,  >hows  that  the 
^freater  numl»er  of  «ir'i  les  of  each  jfenus,  and  all  the 
species  of  many  K^'itTa,  have  lelt  no  descendants,  but 
have  hecome  utterly  extinct.  \\  e  can  so  far  take  a 
pn)phetic  fjlauce  into  futurity  as  lo  f«)retell  that  it  will 
he  the  common  and  widely-spread  sjiecies,  helontrin)?  l4) 
the  larger  and  dominant  jfroups,  which  will  ultimately 
prevail  and  procre;ite  new  and  dominant  spe«ies.  As 
all  the  living:  forms  of  life  are  the  lineal  descendants  ol 
those  which  lived  lonjr  before  the  Silurian  epoch,  we 
may  feel  certain  that  the  ordinary  succession  by  ^jenera- 
tiou  hiui  never  once  been  broken,  an<l  th.rt  no  cataclysm 
has  desolateil  the  whole  world.  llen«o  we  may  look 
witli  some  contidencc*  to  a  .secure  futire  of  equally 
inappreciable  Icn^'th.  And  a-S  natural  selection  works 
solely  by  and  h)r  the  >roo<l  of  each  l>eing,  all  corporeal 
and  mental  endowments  will  tend  to  pro^rress  towards 
perfection. 

It  is  interesting;  to  contemplate  an  entangle*!  bank, 
clothed  with  many  plants  of  many  kinds,  with  birds 
singiii::  on  the  bushes,  with  various  insects  flitting  about , 
and  with  worms  crawling  through  the  d.imjt  earth,  and 
to  re/lect  that  these  elaborately  constructed  forms,  so 
ditieii.it  from  each  i»ther,  and  dependent  on  eacii  other 
ni  so  complex  a  manner,  have  ail  been  produced  by 
laws  acting  around  us.  1  hese  laws,  taken  iu  the  largest 
••euse,  being  CJrowth  -vith  llepioductiou  ;  Inheritance, 


KK(  Arini.ATlON'    AM)    (ONCLlSIoN    441 


*liii  h  in  aiiii(..>t  jiiijilie«l  by  n'j(r<».iijction  ;  \arialiilitv, 
truai  l}jf  iudirett  and  dinrt  action  of  tiu«  exUrual 
.  I'.'iditiou-  of  life,  and  from  tist*  and  disus«'  ;  a  Hatio  of 
Incrfase  so  liii:h  ;ih  to  load  to  a  MrutruU*  for  l.,f»',and  ah  a. 
toii.>.e<ju«'iit  e  to  Natiinil  Selection,  entai!;fiir  hiv.rjrnce 
'if  (  harai-ter  and  tlie  Kxtim  lion  of  le>,s-irnprnveil  Nirmn. 
lliUH,  from  the  war  of  nature,  from  farnuie  and  death, 
the  most  exalted  ohicrt  which  we  are  ra|>Hhle  of  roii- 
iviviii:;,  n  inu-ly,  the  prodta-tion  of  the  hitrher  animal-, 
tiirei  tly  tollows.  There  is  irrandeur  iu  this  view  of  life, 
•Mill  iLs  several  powers,  havinjf  l^'en  ori^finally  breathed 
I'V  the  Creator  into  a  frw  furins  or  into  one  ;  and  that, 
v^liilst  this  planet  has  gone  eyilirii;  on  .n'  ording  to  ti,- 
ixed  law  of  ::ravity,  from  sij  niinple  a  heirinnin^f  eiulle--" 
lorrufj  movt  beautiful  and  most  wnnderful  lia\e  ijee:', 
ain'  are  beinjif,  evolved. 


I 


I 


, 

1 

In 

1 

INDKX 


AlriRlVT  (TTOUp*,  iSU. 

Abyiuii.i*.  (,  »i,u  of,  33«. 
\ccllni»'i'i»'.Mn,  Ijt',. 
Afflnili^i  (if  "fxtiTin  «f)«<i«>«.  .>yj. 
— -  i)( '•n(nuir     -  [i^«    370. 
A({a»tiJ  UQ  AinblyopHt,   | -.M, 

—  110  gro'ijMof  itpot.  ■«  itu-ldptily 
•  ppfATinc,  271,  .'73. 

on  embrjrokjj..  al  ^ucrmiiion, 

SOS. 

—  on  the  i{'»rl»i  p^ri'^l,  32S. 
on  embry.j|<>({ic*l  i.  :^»r»c'*r«, 

91  7. 

—  on  lh«  ambnrot  of  vertcbrmta. 
S94. 

— -  on    [i«r»llpllim    of   enibry.>- 

lojfir*)    .lev»'lopin«'nt    »n<J    goo. 

IcHjipAl  ■<iro»H«ton,  404. 
il)?»  of  Srw  Zetland,  8:f7. 
AIlt({»toni,  malen,  ft^htinj?,  SO. 
Amblyop«i«,  blind  ti»h,  IM. 
Americ*,  North,  jiri-liirtionf  »lli(»d 

to  th>>M  of  Knrnp«,  334. 
— ■ boulderi  »nd  zlacinrtof, 

SS4, 

—  South,  no  modern  fomutiorui 

on  wpit  cout,  2tO. 
Ammonitea,  luddsn  exUncUon  of. 

2SH. 
AnagilHii,  iterillty  of,  2.>-?.  i 

An»loicy  of  variation*,  144.  ! 

Ancyloa,  S4«J. 
-AnlrnaU,    not   doniMtiruiLad   fr>.tn 

t>«inK  variable,  IS. 

dorriMilc,    dr*r«niled    from  ! 

»e»iirml  •tocka.  17. 

accliinatiMti^n  of,  128.     i 

of  .\ualiitiiit.  iOi. 

with    thiclinr    fur    in    cold 

climatM,  121. 

blind,  in  otm,  124. 


Animal*, •itJDct, 'if  Auatraita.  S04. 

Aii"irima,   .'l'.. 

Aiitan-tic      laii.lii,  ancieut  flora  of, 
,       3,'.v. 

AnUrrliinmn.  M'*'. 

.\iit»  atU>rnl;ni;  i;.hii|p<t,  ISO. 
-  ^laTB-inakiiiK  lti»*.inrt,  196. 
'  —      nmirr,  «lr'ii-turi"  cf.  21?. 

.^^)hul«•«,  atUti'lml  t,y  aritfl    189. 

AphJi,  devnln.iinT.'  ' ,1,  3"'. 

Apt^ryi    1«4. 

Arab  fioriw^,  81 
I  Aralo  ("*j.|.ian  s^a,  804. 

An  hue.  it.  do,  on  the  iticccaaioa 

of  »Jl»H'j.-«.    -^'Il, 

Artichoke,  Jonnalem,  IW. 

Aarenaion,  planu  of,  i',it. 

Aacloplaii,  po'len  of,  174. 

Aa|iara4(ita,  3'J3. 

.\ajiirarpa,  376. 

A»N(>a,  •tr1jj«»'l    147. 

Atf-uchna,  li'a. 

.Audubon  on  haUu  of  f|-iira tit- bird. 

lrt« 
on  variation  In  Liirdi'naata, 

190. 

on  h»ron  "atinjr  loeds,  SiS. 

Au^traila,  animals  •  f,  105. 
-  -  doKd  of,  1»3. 

eiUnct  -inirnali  of,  304. 

KurojK-an  plant*  in,  SSI. 

Azara  r  n  fli»«  deatroying  c«lile,  OT. 
Aw>rf»,    i(.r»  of,  32i). 


on  Britiah  plaata, 


UabiDKUuii,  .Mr 

46. 
[ialancemont  of  growth, 
l(aniboi)  with  hooka.  177 
Harf<TTy,  flowfr*  of,  S9. 
H^rranrie.  M.,  on  Silurian  coloai«a. 

t81 


I 


44.T 


«li 


<'N     IIIK    oKKilN    (»K  M'K(  IKS 


I'f  il/tri'lfS,    •.'.'1. 

on  j.nr..  •li^in  uf  |«I«<i/(ii( 

funiijkii.  1,4.  •j.M. 

'<!.  »i;':,.tir.i  Iff  »r     .i>:.t  «|*,-i-< 

.•..iMifm,  luiiMjit^i,, ,.  ,f.  312. 
lU'. r»ch.»ii«  (,ii  in,, ill. In,  363. 
I.d',.<,  tiii*  Htrticlijf  »c<imr«j.l,  i«-,' 

-  Jixlr  :i  ill. .11  .,f    3',4 
H'M  c*Uhiii|{  w»l«f  »n»e<U,  lU'. 
n.-",  •tlr.j!  of,  l.«2. 

-  —  liUot-ii,  killitii;  nv«;«,  ipj. 
''■<>«•  frrlilinii.^-  rt...«.  r«,  (.M 

—  I.KO.    liol   ■ULking    ll.«i    fp.l 

—  -    li  »••,   Cflluiaklng    limuicl 
01. 

—  li?.llll.l»l,  C''l«  ..f,  ■.'ci'.'. 
■     -  pAikiiiUr,  li((, 
l>-><ai'M,  i»iii>r>.»,  III  M...!^ii»,  r.'3 

—  Willi  ileii.  .eiil  tir'.i,  li,; 
!t"nlh«ii,.  .Mr.,  i.n   l!rili>.>.   u\nu\i 

♦i. 

lui  ■■..■»->^ii.c*tlfn.  377. 

H.  rkeley,    .Mr.,   ou   Bf.xi.t   m  ulu  i 

BormU'lm,  b.rli  of,  351.  i 

llinln  •Ci'iiriii^'  i.ittf,  Ux). 

antiufcUy  cruM  U.e  AtUniic. 

3:7. 

—  I'ol  iiir  iif,  un  coiitineiiU.  r,iU. 

—  fix.utr|«(  »i,.i  rnmiia*  i.,f,  lu 
^r.ouilary  io<»<,  J72. 

—  foiisil,  in  i-»>r<  of  i!r»z.l,  Sot    ■ 

—  uf    Mi».i^ir»,    llnrniuJa,    anil 

'  i».  .1.,;  of  inalc*,  ,>■.). 

-  tr»i.«l.<.rl;;.j'  •i-edi,,  a'^4. 

»*.l"i«.  347.  i 

»nri>;lei«i,  122,  MS.  1 

-    -    witii    ii»e.--s    uf    embryoiiii- 

;«.lh,  4u5. 
1...'  A'-ha,  314. 

-  -  aflil.il.r.i  of,  3.^11. 

BUddur  fur  (wituiJiiri)(  in  fli^h,  171. 
UliO'ln*-**  .jf  cave  «!iim  «U.  1^4. 
Hlylh,     ilr.,    on    J.kUi,.  inra*    of 
Ir.Jun  iaul(»,  17. 

—  .)ii  itlripe^  Heinioniis,  148 

•  on  CIo»^«i  (JfSB,  "J.T. 

K.*r,  shoul.l.!r-i.».l  of,  no. 
ii.iiiow,     .\ir.,    ou     liie     sipauish 

I»nnl*r,  i;. 
B.  r.f  St.  Vii.  e:it  ..n   liatraihia:  -, 
\>^3 


llo»'l'iPt,  M  ,    I.  I  tii:Chtl  -.nial   • 

:J73. 
B.iul.|«r<,  erracr,  on  the  A/,  re*, 

3-'.. 
Ilraiirfii*.  171 

llr^t.',    ilr.,    .  r<     huiii(»».tiirii'.,"ri 

1  ;<. 

on  l.awk.'i  kioui,.-  i.:^.-.j?i«,  fib. 

llri>»>r,  |ir.,  oi,  AiinTU-an  cu<-ki>o 

1.'.. 
liiiUiii,  niaiiiii.alii  i;f,  3,')i. 
liroiifi    on    .lurati(;ii    uf    iij*rif5c 

f'<i  .    .  .  •  .. 
Iin>»i.,  K,  »..  11,  oi,  .  .a.>>,i,.aiion 

.-.71. 
Hue  It  man  oil  varialLm  in  j,.ajjU,la 
liu/ar.   1  ,:  ,.-,  ,,i,  n,  ..litjr  of  »ar.e 

lir-i,  •.'4.. 

<  .bba^jB.  vaiicliiMi  of.  cru«»«»d,  M. 

(  aic«..lar,a.  ■:.<, 
'  t  anarybii.i*,  at.-rilily  of  livbril* 
t       226.  ' 

Caj.e  il«  Venlo  Is.anN,  Sis. 
I  C;ii«  of  (;<«-!  II    ;-.,  |,.aiit.M()f,  100, 
'       .36. 
1  (  :irri.r  i.i>;eonii   killwi    l,y  hawk* 

!  C'u.»>ll.i    nii    (low-rs    of  l-r,ii,lM>«il«. 

lai 

laLa."!'-'  'iiii,  3^J. 

ial.«,  wild  bliif^V'S,  linaf,   11. 

variation  iii  habiU  of,  ^2. 

curling   Uil    wlieu   ^.  iij>{    la 

■linii>;,  ISl. 

•  ..lllx  clKatroyinc  flrtieo*.  iM. 

li-HlrojoJ  by  fliea  in  I-i  i'iala. 

t.V. 

brrieiU  oi',  Ir.<-ally  exl.i.   ',  loO 

fennityof  li.iian  an  1  turo- 

l>ean  bn-i.U,  •j:js. 
'ave,  mhabitanU  of,  blin.l,  124. 
(  .  nrrnn  of  crealL.ti,  3i<'i 
(  ifjihal.  j.-l*,ilev>-:oiiiiif!ii  uf.  3i(7. 
I  >rvti!.,.H,  .'•.';. 

«'B*.i.ct%a    if'-th  and  hwir,  131. 
C  1  yiitu,  piauU  '■{,  c  •■. 
VAuik  formatioii,  2s.'. 
CLaracters,  divfii^rMj.  of,  101. 

..ift'ril    vanabi'".  K'.2. 

n'la.livBor  au»lo»:.o4l,  3*4. 

I ''  :i'io<K.  7o. 

'  li(«t  ni  to  inc-na.'iP   fi2. 

mutual    '7. 

(^ii•■^^,•D.•^  laatiaouve  taiueii-ta  of, 

l:i^4 


^-*1 


iM>i:x 


445 


-«•■. 


e'litli»tn»IiM.  crxT«rr«n  »n«rl»Mi  nf 

■j:j. 
rTcum^utifoi  f»Tfiiirmt'lf  to  ••  i^i-. 

Moll  of  <l<'fn<"->t  .    t,r(i<|iirt«,  ?;. 
-— —  - —  U)  rii\''ir»l  •'•Ifvtion,  v.' 
<"'rrip«s<l««  <*|»M«  of  ■•rM,«itnj.  '.<1. 

-  i'ar»5*f«  «i).irt*».l.  l.'^^ 
tti.-ir  c'vijfiToin  frrtia    IT  ' 
f  .oil.  27-i 

-  Urv»  .if,  3'">. 
*  i-«»'.'nr«tlon,  STO. 

'"ifl,    Mr  ,   on   lh»  •iirco^non    of 

Cliitiat*.    ^r.-rm    of.    in    rli-ck  •  p 
lnT«»(i^  if  !i-  in'.-s,  f:i 

»<l«iiUti',n  of,  to  ori;tni!im!», 

126. 
'  obit»!«,  iritp\i!tiH  of,  171. 
'  ockrnarh,  70. 
Co!l«cUon«,  j«I*or)toli)Ki<-«!,  r  ,)i,r 

2i8. 
Colour,    lnflu«iic»d     by    clitnai«. 
120. 

-  in  relation  v>  ttwrku  by  (i:tn 
VS. 
i"<.!tmih»  livin,  par-ni  of -JomMtic 

p'i?»')ii».  iM 
(■<)lynil)ft<*^.  3;fi. 
(.'ompensati    ri  ..f  ^.-rrjn th.  !.?.•? 
f'^iiiilxwiU!,  out^rsnd  liiti»r  tl.>r.-t» 
of,  131. 

n.a>  fluw»rv  nf,  4CW^. 

Oii,rl'i«i"n,  general,  432. 
f'-iiniitiotn,     ulight     rli«nc»i)(     in, 

fcvoMrabl*  to  fertility,  2:<9 
•'oot,  l'-7  I 

' 'on\[nhin<\n,    n^^n    drlfUxl    to 

■■•■•u. 

— -  r^U,   inciirating   movements 

of  ear  !i,  "277. 
C<Tii-cr*lv'-.  1'''7. 
C()rr>^latu>n  "f  growih  in  dom-^stir 

ppi-inctio-n,  1 1 

"f  KTwOi,  I:".),  178. 

Cownhji,  41), 

Oeali'.ti,  ain^'le  ri-ntrefl  "f,  818 

Crnum,  22*. 

{,>i»(».>«,  r^iiiTfi.  i:,  231. 

Cro'^Mun  of  d■)m»•^tio  anliualH,  |m 

!»)rlanre  in  alt.>riiiif  bre.'.l.;^  js 
ftdvantAi.''""  of,  »■>. 

UriT^V,'.'       »">;r  III  >'*ir^"U'  :i.  '.*'2 

<^ru.itac«l  of  New  >:'»aUnd,  337. 
rnLstarean,  I'liri'I,  1J5. 
''ryptiiceru.i.  '.'14 


I  f't'-nomj'i.  hhrnl    i;*. 
f'i'-k'x).  ln«titiri  of,  ls»5. 

I  <'iirTRnt«,  irr»rt»  of.  ^3^. 
fiirrenU  ■  f  ••«,  rBt«  of,  321 
t'uvi^ron  r./tidaioni  i.f  ex  .(,n<-» 

I ■  "')  fo«»(l  monk#«jri    2;. 

^  f"<l  ,  on  liiilinrt.  1«7. 

I  l»ai>4.  Prof., on  blind  ravp  iiurraU 
i      1-J'i. 

-  on  r'laMona  of  cr'i-ia<-.>4n»  1' 
J  >|-*'>.  834. 
—  nn  rri*uraan«  of  N«w  '/<•% 

lifd,  B.C. 
i>e  I  an.lolle  r.».  atni»;^->  f.,r  ei.it 
enf-e,  j.s. 

-  -  on  umti^llifiTir,  13J 

-  -  on  ^^en^•ral  aHlf.itie-.  S''7. 

-  -  Alph  ,  01,   I..W  |.!arit*,  wi.!..Iy 
l.^pf-rsod,  fiS, 

"n  wl^lymnKinp  planus 

'■eing  v«ria(  Ic,  4'<. 

-  -  --  -  on  na'.iirmlioaHon.  104. 

on  win_"d  iewN.  I:i3 

""    A!;-!-:"   aperiefl   sud- 
denly he<-t,niM,k:  rarn.  ii7. 

on  di<tnl»  I'lon  of  platita 

with  Ut,'--  i»e«l»,  S3 4. 
oti    veuKtaUon    of    All* 

'm!i».  S40. 

on     fnwh-wattT    p'antu, 

817. 

— on  ln«iilsr  plants     ,49. 

I>'';Tad»tion  of  coa-^t-PK-k^    .:.,3. 
l»fnndaticin,  ri'w  of,  'J5>i. 
of  oldMt  T'M'kn,  27a. 

neyelopmeiitofaiiri«nlformi,30 
Devonian  «y»t.»'m,  2'.''.'. 
I>i»nthm,  fertility  i<f  rr-<\!tKn,  230. 
I»lrt  on  fuel  of  birds,  S.'rt. 
I'i-ii*ni»l,  roeani  of,  82n. 

du'inc  iflacial  i>*>ri^!s   328. 

l'i.>tnljuti..n.  ft'-'vraphi.-.i:    S'tt. 

niear;<<  of,  S'.'i). 

r»i»ii«e,   p|l«cta  of,   under  nature 

1 .'% 
[iivorjfonrf  of  rhararl»T.  loi. 
IMvision.  physioloiru-al   of  laUjur 

105. 
i'  u's,     halr:e«.«i.    with     imiwrfeot 

t»^th.  II. 
'i-HCi'nd-d   Ir-'TO   •fv<-ra;  wiH 

"tH-K-s,  17. 
dumemti'-  inii'ir^e»«  c,f^  j'l; 

-  tnhent'-d  civiiisauon  of.  1;. 


I 


(■f 


44«  ON    THE   ORI(;iN   OF  SPEriF:S 

lM«s.  fertility  c;.'  br.»t.ls  u,Keihpr,  I  Kalron^r,  Dr..  on  t,«i..r»li«tloi,  of 
^'  '         ,  I      plant*  in  India,  fiii. 

of  (Toss^H   •_'4n.  i  .  _  ,„.  f,„„,  er.H:.,.|.le   '.'Sl 

--■  I.rui..,rtloii»  of.  wh-u  yonu^.  |  —  on  Heph.nu,  .,,.1  ma.st«lon. 

Uo>*„,r.j„    Mr,.   „n    fruil-treeH   ii,  ,      Hul.-lli„,ai.-iv»n  U-,lh    Xoft 

AMi-Tica,  ,,.  i  F»!kiAi„i  Inland,  wolf  of  ai^ 

0<.w...s,  N.ull,  «n.i  H.,u-.h,  2/(1.  ,  luulU,  -55.  ' 

KiiinM  marine.  813. 
K'-ar,  iruliti(ti\e,  in  lurrN,  1;»0 
K>'»'t  (.f  bipJa.  yijuii^  moilu-.ru  6.1 

hfnnn  U).  iHfi. 
FT'ility  of  hvhrlilg,  2'J4. 


iJriK'oii  rti"!.,  iiif-'tini-ii  of,  171 
linfi.  tiiiihor,  324 
I)riv.-i-arit,  ;it>. 

l)n.iir«  kii;r,|  i,y  olhcr  b<^s,  1S2 
Uark,  dt.'iirsuc,  wincii  of.  re<iii.'.^l, 
III. 

loKKT-ii^-idM,  liiS. 

Uuck  WC.-.1.  34fi. 

l"i«.iiii{,  Hilliiitii-.i  of.  37:j. 

D'uiK  U-i-Ufs  with  Uclifienl  Urm 

Ii;.  tioiid,  846. 

K.ii,    Mr.  W.,on  the  Malay  Arihi- 

\"-i*.H'\  »55. 
Kars,   <in>jjiing,    In   domestic  am- 

II. ai;*.  II. 
-  ru.liri;,.ntary,  408. 

rcno>;  "■'?  '"  ^"'^  '^  '""■■""  '-*■  ' ••'^^"'=  "^►>-'"'«  ^'^'  l'3. 

K.-o,.o.ny'of  orpmixaMon,  134  i      •^m"'"'""^"  """*^  '"  ^'■•■•''  '"^'' 

'^'""'V':?'*;  r"'  '"",'':':•  '"•  of  ...nti.en.  fi..m,Bph.r..  837 

ll.'.>«»M!<.    MlliiC,  oti    filivsioli  gicai  i        lrV4  ^H"'"". 

'"'TTJ/J* '*""'■  r"*''  ^  ^"'  '^'''■'''  ""-.K-tun,  of.  in  relation 

— -^..u    (fradatjons   of    Mnu-tur.'.  _       to  cronsn,^    S.i.  ""»"on 

-   -of    comiMMUe     and     unibel- 


-—  from   iJi^d.t  chant-'-s   in  «son- 

dltionif,  2:iy 

of  cTi..Har<l  variftipji,  V40. 

Kirtrej-s  destroyed  !,y  cattle,  ftfl. 

[«  lien  of,  ifj. 

Kish,  fly;n,<    lo4. 

lei.-,  p.siean,  .Hu.ldpii  apj>nararir« 

of.  '.'T.'?. 
-—  "atinu  Be.wi8,  S2,s  347_ 
-       fri-.th  vrator.   d.Miibiition    of 

344. 

frt'sli  »  attT,  if". 


._""  '♦"''"■yoloKir*!  charactftrM. 


377 
Klvs,  younu  birdx  oaca|,iiig  from, 

Kiwiric  ir.ans.  I7s. 

K  r-jiliant.  rale  iif  inoreajic   rtO. 

•f  ^'Uciai  periml,  r.'t. 
l.iiiliryol.vy    8'.M. 
HxiHt»'nr<»,  -irngnle  for,  in. 

—  coiidit     n-.  (f,   Is.. 
Kxiitu-tioii,  a»i  U»ari'i({  on  natural 

KeliHti  111.  !»9. 
of  doriestic  vartciifi,  \ri\ 

K.in.  Kir  lotur^  iif.  16k. 


li^^ra-,  131. 
K' -■    .-i.   H.,   on  rol-.ur!<  of  shell*, 

'      -  "n  abr-.i>l  ranK'  nf  »heIU  in 
■Ifpth,  l',7 

—  on     }).H)n;o«,     ,,f     {rtii^onto- 
!oKH-al  coll'-i-tiiins,  -J,'-. 
-  on  coKrinuiiiis  Niu-ctw.sion  of 
gt«nfrH,  2S4. 

in     r.intineijtal     -xUr.»Uni» 

3'2v. 

>  n  didinbution  •!  irin^  ».'lacial 

on    jiaiul!p|:.,ui   m   uniH   and 

si-ccf.  S'i."-. 


■■ccrm'tiMMcrat-n-ation,  IM.      h.   ^sU,'  c-h»..^-«  in     .n    \,...,,ca 


.J 


,.  i  ■■!  ii.iTii.ii,   i->-V"(.::tri.  -.r.' 

Fsi.r-      -M..    ,.,,     j^ra^iuc     -phex      K,.nuat,.,„,,     ih,ckn.-.Hi 
'•  '  UriUiin,  j.'^. 


of. 


in 


•sm:±i'Ji^3ss^ 


INDEX 


447 


Fi  rrr.itiojii,  int*rniitt*'  .t,  2Hi>. 
Foriiiica  njffsc-i-ris,  liH). 

■'>»ii)?iiiii'u,  Iw;. 

-  Cava,  neuter  of,  215. 
hrNa,    nvigt.r«ju»,    of    c!mpe<lM, 

Frf»li  water  production!!, dltpersal 
"I,  3U.  ^ 

Fries  .,n    mj^-jm   It;    lar^re  genera 

t'T-.u^    c)o«rly    allied    to    oilier 

ni»-ri«»«.   S2. 
Fn,-..t"  l.ir.J.  1(57. 
Kr;)^;'!  on  j^lan.li,  S:.S. 
Krtiitirw's,  i:ra,liiai  improTemBn' 

of,  n 

in  United  staton,  :;. 

--  —      ^ar;.-tiesnf  n,climati.sf«d 

til  Lriil-i  ■'lateh.   1  .'y. 
I'uri.  rrr.fn.'.!    jj-^ 

Fur.  till,  k^r  lu  cold  climat*a.  121 
Fir7«,  3:-f, 

0*;.i|.aj,-o8    Archipelago,   tinla  of 

36 1. 

prfvliictiori!!  r,f,  S5S,  S«Ki 

•  iilfoi.  ti..;i  us,  i()3. 

<iaiiir.    iiioreaae    of,    checkofl     L-i 

V'-riniii,  tiS 
''»rl"-r    on    sterility  of  hybrids 

')n  reciprocal  pro«.se<i.  'jsc. 

un    cn.««ed    inaire    ami  "v  •■ 

l«.«ciim.  •J4i 

01,  c  miariiouof  hNljriil»a!,cl 

mn:,^.r-!a.  J44. 

'■-^ii-.  feinlity  wh<-n  cro««»j    'jjr 

'ililaiid.  I(i7. 

••Miral.iify  imjK^irUnt  ill  c;a.s.>,itj.'3 

'■e->'':t)y   .-^l.    Hiiaire   on    Ulanc- 
ni>'i,i,  i3:i. 

—    on    hoBKi;  ;^-.)!is    orjaoM 

'■••Ml. 

Isidore,  on  »ariabiiif  v  of 
rt-iK'.ite-l  juit»,  i:t', 

■  en    ro.Tflation   In    mnn 

slroaitips,  1 1. 

"'1  onrre.aUon,  130. 

'"'    vtuidbi^  {*rtn  tieinc 

<fT''ii  nionstnim,  I  (a 
'•eo^^rai-liical  <ii.nniiiition,  805. 
•»«<<>-.;raiihy.  anciem,  O,'^. 
'><.!'. .7.  fuTure  rrocret.-i  of.  43S 
---    .ii,j)rr.<rcnori   u;    th^   recorvi. 


•  Harial  penr>d,  s?«. 
•irnelm  on  tlmlrtmtion,  S.'S. 
'iriall  (kIoii,  foajtil.  ;i30 
G.xln.nAiiKt^in.  Mr.,.>n  tl.-  Mvn 
^  ArchTf*latro,  •ji;h. 

Ooetheon  cutnpenjatiiiof  f  K'ruwth 
IS.T.  ' 

(}oo«fr>erry,  graf's  of   2.'<.'. 

(}oi;l-i.  hr.  A.,  on  lar' !  r-h-li!,.  svi. 

Mr.,  on  iDic'ir^    if  t.ifl.^    I'.'u 

^        _on    Mnis   of    il,«   i;al«t'.»^;.i«, 

vt>  (listribiilion  „f  a,-uen  of 

I  Ooi.rii<,  cri»..se«l.  242. 
I  <irarti,  caf«<-cy  of,  •J:^4. 
'Jr»Me!*,  var:>-".iP!i  of,     ii.T. 
'j  •>    ,  Dr.  A-«a,  .  n  tiv.-s  ,]{  fnited 

St-t*-!*,  91. 
— -  01.  i.atiirati.e.1  pianta  n,  u.e 
L  i:iil.rd  S!»>s,  KH. 

on     rarity     of     iii!ertn>«li»u» 

varieljrs,  i;,s. 

on  AlpMif  plantx,  ?-:n 

"•"•   J-    ^     ""   nlrij-^l   n.iile. 

(ir.t,e,  itv?. 

•  iroiips,  al.«*rrant,  3^6 

iirOi..se,  C4)l():!rH  of,  77. 

-^ —  red,  a  .ionbtri;  ,>^^cii's.  4i 

'ip'Wth,  rorni^nsatiuh  of,  13;',. 

—  <-.,nv|atii>n   of,    in    .Ion ctie 
pro<luii.i<,  II. 

Ci'rrflation  of,  1211. 


'..irarr»   Ui!  of,  175 


Habit,  effect  of.  under  d.-meKtlca 

lion,  10. 
efffct  of,  under  n.-ilure,  12-. 

—  dnersified,   of   >ian;n    '' .erien 

1''5. 
Mair  and  t^'f'th,  I'urrel.ite*!    131 
llar.-,.urt,  Mr.  K    V.,  on  the  bird. 

of  .Madeira,  S.'l. 
HartiuiK,   M.,  on  Umlilem  in    if  , 

Aiun'H,  320. 
Haiel-nnt-s.  323. 
il-imeon  habits  of  !,eitrs.  iri.-). 
n»ath,  rhani(e»  11,  vej(.>t*^  ioi:    f,'-, 
H'-r,   O.,   on    [.1a'.:.«  of   Vh..!.-  r» 

He!n  pr,matia,  3.'.7. 
llf  ii^ciaiiiam,  Siij. 

llert>ert,  W.,  on  (itrii^-!-  for  exinv 

ecce,  5.H. 
or.  nf«H:ily  of  hybrids,  22* 


k 


\t'< 


■f. 


4J8  OS   THE   ORFdFN   OF   srPX'IKS 

Hiitt'-JD,  C«i't*in,  on  croM«>i  gftcvi 
••■_>7. 


nnx\ty,    J'rof,    on    iitnirtiin'    of 

hpniia]i!irf.'Iit>>s.  PI. 
on  em'..!  y..l<i^;irAl   siiccensjor: 

S05. 

"n  )i(jrr''ln(jonii  oivnTj.H,  3'<4 

on  Die  liovelonm''!!'.  of  »|)!i:t 

3.<7. 
flytrid*  »t.d  nionjirflg  rnniiiart-.i 

■-'44. 


tl'>rrn»p!ir(i'iii4',s  rros.>.iti(;,  87. 

ilcron,  .Sir  K.,  im  i^-arfyrkH.  PI. 
Heusincftr  on   whit«»  «iiiiiiaU  not 

T-ois  ii.».l  1  ,  c»r1.iin  pi.-iiitfi,  11. 
U-wr.t,   Mr.,  on   •t^rility  of  first 

cr'.(iii(»s,  ^/.i', 
Himalaya,  ^'  iriPTn  of,  S35. 

plaril  ^  .if.  :vfi', 

H:j.i.«!«»tr;:m,  JJ.i. 

Hilly-trw-n,  «Mt..a  of,  9.* 

I'  ^lyhock,  r-^!:'-'.ic<   of,   rro«sf"<l,     II  ■.  lir.dism.  •.'■.•0. 

2*3.  'Ivlri.  RtrucliiiT  (if,  1-] 

'looker.    Dr.,   on    tr"<>»    it    .\>w 

/>ttlanf1,  M  li.la,  134. 
"•!  if' T  it;-iation  of  Mima-     k^lwr-s '.randi.orti.'ij;  st-cln    S"*? 

..■4y;in  trp»».  1'.'7.  Inrreaaa,  rate  of,  59. 

—    on    flowers   of   amti-Uifpra-,  Iri.!ivi(iMai«,    numbers    favmirabU 

'2'-  i      txi  H'-lertion,  '.fj. 

—  on  pla'i.-rsnf  HiniMaya.  .S.-W.  n^nv,    whether    uln.nltane 

—  on  alp*  of  .N>w  ZHalaiidl,  337.  ,      ou.hIv  rr-Ato<l,  31P. 
on  v<»-cia;ii)ii  at  lhi»  ha«p  of  InhrnUi.'-..,  laws  of   Iv! 

thf  llir  alaya.  340.  at  corrf.'^i.onil  nc  au'--"    13   7^ 

on  jiiaiiiH  of  'J  ■.•md"l  KiK'po,  In-ct.-',  colour  of,  fitt**.)  for  hahi 

^■**   339.  t«tioM»,  77. 

-  "li     ^uitraliaii    planus   337,  K'-«siJ<>.  colours  of,  r.;o. 
-  l.iiiid,  ill  cav»>s,  I'.'.'i 

—  on  relations  of  flora  of  South luniinc.^    174 

\in.Tii-«.  340.  neuter,  2U. 

-  on    flora    ':t    t)ie    A- uirciic  !•  r-iuict,  1-'.. 

'anda,  84J,  3.'.'.'.  l-i'ititirt*,  dMnicstir,  198. 
on  tiip   planle   of  the   i.fila.  Iil^rrroHsir:..',  ac|\-,i;i*aff»ia  of  SS 

\air,s    3:->.  3-,:.  1  Mi,„i,.  (x-.-inic,  34' 

il..H,ka  on  t.amt.<x>«,  177.  i  IsnUtion  favourable  tc  ael^tion, 

In  .""P'ts  on  iMlanda.  3,'i2.  ni,. 

Ilori.fr.   Mr.,  on  the  aiil'iuily  of 

E^'Vi  •lan.'i,  IT.  .' ■.;»!!,  [.nvinrtionn  of,  S3l 

Morns,  riflifiPnUry,  4  -  .Java.  piaiiLs  of.  ;j,"^>i. 

MorHH,  f,,s«il,  in  Ijl  Ti.-iu   '.'fir,.  j   ,,..«,  Mr.  ,1    M  ,  on  tlin   ',:nii  o' 
Mors-N  (ifmtroyfvl    by   !!:.-s    m    Ij»         Hermu.ia,  3.'.1. 

r.at.i,  fi,.  Ju'tB'-n  nr,  cI.TiHiflpation    3":. 
^triji^d.  14s. 

—  proi>or!u)ns  of,  when  younp,  K'ntuoky,  i-avrs  ,.f,  l;'4. 

,*""•     ,  K.'>;uPl."n-lanil,  flora  of.  342,  S:-- 

HorT.(-iltun3l.-<,  8f>l.-otion  apjilie-l  K   In.v-b.'an,   acrl.!n.ti..sati -n  of. 

by,  SO.  '       \'2^. 

n-.'iT  on  r-lN-  of  l.ciflii,  207.  IsMnrys  o    t.,:  1,<,  i.i.i. 

—  1'.,  on   rca-s..!!    bl«i:.led   with  K:i  l,y  .m  urs;  .u'ticiont  in  \^li-i, 
Uivtincl.  l^T.                                      ;       ;  j-. 

—  on    h.it.iltial    i-aiur.'   of    in-  ]  kni^.ht,    An  !r"-,v.     ,,u     cause      .' 
«'iiict«.  is:.  variation,  7. 

on  «:.ive.niakii-K  aius,  lyv  K  .lp-ut«r  on  the  barJ-orrv,  W 
-  -  on  JlchiHHia  .tonu-stica,  'Jii.'  —  on  stenlirv  ./fhvbn  U    'J-"! 

iiuiiii.i».-i»n»,  .-.-M-itf,  Cvj.  ,n  rcci|.i-.K-al  cr'sap.n,  •i.S-j" 

Mii'lr,   J.,  ,':'  (i.'condary  aexual  .m  cro.-sod  vanities  of  ni"» 

i-h«ra<-len,  13''>.  1      -mjia    •j.js 


INDEX 


446 


Ertlreut«r.  on  crouing  nul*  and 
heriuAphrodiUi  flowan,  405. 

LamHTck  on  tdiptive  cbkracter* 

8M. 
Und-thelU,  dUtribotion  of,  85«. 
- —  of  Madein,  n»tur»li»ed,  i62. 
UiiKU*Kes,  clfcMillcation  of,  l«0. 
i^P»«^,  Kr«*t,  of  tiui«,  Ji8. 
l*Tvr,  Si'5. 
Uur«l,    nscUr   iecreted    by   the 

iHtTM,  83. 
L*wg  of  T»ri»tion,  119. 
I-««<-h,  varieliei  of,  70. 
UKuminofue,   uecUr  secnted  by 
k1»o.1«,  88.  ' 

LepldcMirBu,  97,  2tf6. 
I.lfe,  itruncle  for,  i6. 
LiDKul*.  biluriAn,  275. 
Linn«u«,  ephoHim  of,  872. 
Lion,  tn*ae  of,  bO. 
; —  yonne  of,  itripM,  S95. 
Low^li*  fulKen«,  «8,  riu. 
Jx)beli»,  iterility  of  crOMos,  J24. 
LoBsi  of  th«  Rhine,  845. 
LowneM  of  structure  connected 

with  variability,  185. 
Lownew,  related  to  wide  distribu- 
tion, 8<J4. 
Lubbock,  Ml.,  on  the   nervee  of 

ctxTua,  42. 
I.uca«,  l»r.  r.,  ou  inheriUnce,  12. 

on    re««iublance   of  child   to 

I«reol,  247. 
Lund  and   CUuwn  on   fosada  of 

Krazil,  804. 
Lyell,  Hir  C,  on  Uie  etniggle  for 
exijtBnce,  6fi 

—  on    modem   changea    of  the 
earth,  S6. 

— -  on  ineaaun  of  denudation. 
254. 

on  a  c»rboniferoua  laad-ahell 

259. 

on  «traU  beneath    Silurian 

■yttem,  275. 

on   the   imperfection  of  the 

Keologiral  rttcord,  278. 
Ju  the  appearanca  "f  apeciei 

2(*0. 
on  Uarrande'i  colonien,  281. 

on     tertiary    fonnatlona    of 

Europe    and    North     Am.-rica 

on    parmllellsm    of   tertiary  i 

formatlona,  2<J4.  j 

2 


Lyeil,  Sir  C,  on  transport  of  aeeda 

by  ieeherifs,  82«. 
on  (treat  a!ternatioi.»  of  cli- 

Uiale,  843. 
on  the  distribution  of  freah- 

futer  sheila,  346. 
- —  on  landnhellsof  Madeira,  8fll. 
Lyell   and    l)Hw*in   on    fosailiaed 

•reea  In  Nova  JicoUa;  2C<}. 

Macieay  on  analogical  ctiaractera. 

?H4. 
MMeira,     lant»  of,  y7. 

l-eeties  of,  wingles*.  I'.'S. 

■  r..«ml  land. shells  of,  3<>4. 

birds  of,  S.>1. 

Magpie  Unie  ic  Norway,  191. 

Maize,  crossed,  L'4J. 

Malay  Archipelagocompare*!  with 

Euroi)e,  Jrts. 

mammals  of,  855. 

Malj  i^;hiace»,  875. 
Mammie,  ridinienUry,  404. 
Mammals,    fossil,     in     aecondary 

foimation,  272. 

i.isular    853. 

Man,  origin  of  rac-i-s  of,  179. 
Manatee,    rudimentary    naiU   of, 

Marsupial.s  of  Auntralia.  105. 

fussil  Hpecies  of,  804. 

5Iart«n«,  M.,  experiment  on  aeeda. 

323. 
i  Martin,    Mr.    W.    C.    on    aUiped 

mules,  149. 
Matleuccl,  on  the  alectric  organ» 

of  rays,  173. 
Matthiola,   recipr»xa!   crossed  of, 

232. 
Means  of  dispersal,  820. 
Mrthi«ona  domestica,  202. 
MeUmorphism    jf   ol<le«t  roeka 

276. 
Mice  deatroying  bees,  «8. 

aechiriati.Kation  of,  128. 

Migraliou,    tmars  on  first  appear- 

«•  ee  of  foaslU,   2rt7. 
Miliar,  Prof.,  on  the  cella  of  Uma. 

203. 
.Mirabilis,  rrosses  of,  J82. 
.MiHsel-t'i.ash,  7u. 
Mist'  ".oe,  complsx  relations  of,  8. 
MfS(;  sippl,  rAle  of  deiKjfitlon  at 

u  •   lih,  266. 
Mocking  thrush  of  the  Galapagos, 
8<51. 


M 


460 


ON   THE   ORKJIN   OF  SPE(  lES 


Mrj«liflcatloD  of  8p«cieii,  how  far 
applicmblr,  43.S. 

MolM,  blind,  124. 

lJon»<T«lN,  fertility  and  aterility 
of,  -'40. 

and  hybrid!  comjiared,  244. 

Monkeyn,  fosnil,  272. 

Monocanlhiii,  3H2. 

Mods,  Van,  on  the  oriicin  of  fmit- 
trces,  27. 

Uoqiiin-Tandon  on  Ma-ildn  plantK, 
l.'O. 

Morphology,  8!)0. 

Mnzart,  masinal  powers  of,  188. 

Mud,  seeds  in,  347. 

Mules,  8tni>ed,149. 

Muller,  Dr.  F.,  on  Alpine  Aus- 
tralian plants,  337. 

MurchiHon,  Hir  R. ,  on  the  for,  a- 
tioris  of  liuHtia,  '.'.'>9. 

on  azoic  foriiiatiriin,  275. 

on  extinction,  285. 

Mnst^la  vison,  161. 

Myanlhus,  3S2. 

MyriiiecocyitiiJi,  214. 

.Myrmica,  tyta  of,  216. 

Nails,  rndimpiitary,  40S. 

Natural    history,  future   progress 

of,  43fl. 

selection,  78. 

system,  372. 

Natuialixatioti  of    forms  distinct 

fruiii    the    iii<ii^;enou«    species, 

104. 

in  New  Zi-aland,  Isl. 

Nautilus,  Hihinaii,  275. 
Nectar  of  plants,  S3. 
Nfctaries,  how  formed,  !<4. 
NHluinbium  luteutn.  848. 
NextM,  variation  in,  100. 
Neuter  insecUi,  212. 
Newman,  Mr.,  on  humble-bees, (W. 
New  Znaland,  productions  of,  nrt 

p.-rf-.t.  181 

-  naturalised  proiiucts  of,  302. 

fo.sm'i  birds  of,  So4. 

glacial  action  in,  33.'j. 

-  —  trt.^tacuai.s  of,  :137. 
alk'»-  of,  337. 

nunib'T  of  plants  of,  350. 

flora  of,  950. 

IVi'Otiana,    crossed    varieties    of, 

—  certain  species   %-ery   sterile, 

«ai. 


Noble,  Mr.,  on  fertility  of  Rhodo- 
I      ilendntn,  22fi. 
No<lul>-s,     phosphatic,     in     asolc 
rocks,  276. 

Oak,  varieties  of,  47. 
;  Onltes  ajiellfM,  122, 

f)rchis,  pollen  of,  174. 

Ur^ans  of  extreme  jwrfectlon,  167. 

electric,  of  tlshes,  ITS. 

;  of  little  imjHirtance,  175. 

j  homologous,  S'.O. 

I  rudim'-nts    of,   and   nascent, 

404. 

Ornithorhynchus,  !>7,  S7,'i. 

O.strtch  II  .1  capable  of  Hi^rht,  122. 

—  habit  of  laying  egK*  toget'.^r 

i       '•"■• 

American,    two    species    of, 

314. 
I  OttT,    habits    of,    how  acquired, 
1      l.v>. 

i  duel,  water,  1««. 
Owen,  rpil.,  oil  birds  not  flying, 

1.'2. 

on  ve^;>•t,1'lvp  repetition,  13^. 

on  vsriati'e  length  of  arms  in 

ouranp-<;ut«iik',  13<V 
on  the  swim  bladder  of  fishes, 

172. 

on  electric  organs,  173. 

on  fos.sii   horse  of   Ia  Plata, 

2.«6. 
on  relations  of  ruminants  and 

pachyderms,  2i>5. 
■ on  fossil  birtJs  of  New  Zea- 
land. SU4 

on  Biiccessinn  of  tyj#«.  3.  ij. 

on  aWnities  of  the  dugong, 

373. 

on  homoloK'ous  organs,  390. 

on      the    riietaniorj  ho>is     (>f 

cepha'.oinjds  and  spidem,  89*7. 

Pacific  Ocean,  faunas  of.  318. 
I'aley  on  no  organ  formed  to  give 

Jain.  181. 
Pallas  on  the  fertility  of  the  wild 

stocks  of  domestic  aniriKils,  Z'IS. 
Paraguay,    cattle     c'estruyeii     by 

tlies.  >'. 
Paras  it.s.  1;X<, 
Partri.l^:e,  dirt  on  feet,  326. 
i'»ri.s  grealiy  uovriupeii,   .ariaiiie, 

136. 
degrees  of  utility  of,  181. 


INDEX 


461 


PuMM  m^or,  lOft, 
PtMiflon,  225. 
Pmcbea  hi  United  Sutea,  77. 
P«M-,  Kr»fU  of.  •J3.^. 
P'largonlum,  flow»!r«  of,  132. 

<t«nlity  of,  i'v'rt. 

Pelvis  of  women,  ISOt 
P»lort»,  182. 
Pfriod,  gl»ci»l,  828. 
Petrels,  tubiUof,  IM. 
PhMianaa,    fertility    of   hybridt, 

«7. 
Pb*««ant,  yoonjc,  wild,     >*. 


Philippi    on    terti»^y    8t«>cie«    In 

airily,  280. 
Plct*-' ,  I'rof.,  on  fn'oupa  of  §p<H!ie. 

•U'ldenly  »p[«»ring,  271,  273. 
on  r»    ■   of  orgmni"   chmiig*, 

2K1. 

on  oontlnaoiii>  aacceuion  of 

genera,  2H4. 

-  on  flow  alliance  of  foMxils  in 
oona«riittve  formations,  il<Jl. 

-    on  eoibryolokir*]  •aeo«8»lori, 

808 
Pierce,  Mr,  on  vsrietinn  of  wolve«, 

83. 
Pigeons  »'th  feathered   feet  and 

«Hn  b^l»e«»n  t«^s,  11. 

-  -   :ire*<l»  desert  t*«<i,  and  uriffin 
of,  IsJ. 

breeds  of,  how  produced,  36, 

tumbler,  not  being  able  to 

get  out  of  oRj?,  79. 

reverting  to  blue  colour,  1)4. 

-  iiiBtiiict  of  luniblins;,  iy2. 
larrieni,    killi^l    by    hawks, 

young  of,  400. 

Pistil,  nidimeiitary,  405. 

Plants,    poi»rniiu«,    not    a'T»cting 

certain  rolonr^d  snitnai.'*,  11. 

»»'lpotion  u[)i)lie<l  to,  .'JO. 

^raiiual  iniinivemeiit  of,  3> 

rot   improved    iu   b«rbarf)U.-. 

coantri»»».    '>. 
dp(ttroy«i  iiy  Insects,  «8. 

in    midst  of  rangft,  have  to 

rtru({Kle  With  othiT  plantx,  71. 

nectar  of,  v3. 

fleahy,  on  seaKbores,  IJO. 

fr»»sh-waU!r,  distributiuu  of, 
847. 

low    in    scale,     widely    dis- 
tributed, 8(54. 


Plumage,  laws  of  changs  In  a«>XM 
of  bints,  81. 
I  Plums  in  the  L'nllM  HUtes,  7T. 
I'ointer  dog,  origin  of,  32. 

! habiu  i.f,  Iks. 

Poison      not     affecting      certain 
coloured  animal*,  Ii. 

-  Rimilar  elTfot  of,  on  animal* 
aii'l  plants,  435. 

Pollen  of  tir-tree*,  182. 

I'ooIh,  Col  ,  on  striped  hemlonoa, 

Uw. 
I'otamogKon,  3*8. 
Preiitwich,    Mr.,   on    Enullsh   and 

Pr«nch  eocene  formatioas,  WA. 
Pr   iroae,  4«i. 

sterility  of,  J2*-'. 

Primula,  Tari>-tiea  of,  44. 

rrot>Hj|e[ias,  134. 

Proteus,  126. 

Psychology,   ^ltare   progreaa   of, 

4S'». 

Qnag»ni,  Btrip.Hl,  148. 
yuinoe,  grafts  of,  2S5. 

ruhtiit,  diapoeitlon  of  young,  IBS. 
liaces,  domestic,  characters  of,  14. 
Ilarehoraes,  .Arab,  88. 

English,  820. 

Itamond    on   plants  of  Pyrenees, 

380. 
K^msay,    Prof.,   on    thicknee*  o* 

the  Hritish  formations,  2M. 

on  fair  «,  255. 

Hatio  of  iiK   •  am,  59. 

liAt.v,  supplar-.ting  each  other,  70, 

a^i-limatisatiun  of,  128. 

blind.  In  cjive,  125. 

Ilatti'-tnake,  ^^o. 
Kca-Moti  an<i  in-diDct,  187. 
Ue<-a|'itulatu)i.    (;>>iieral,  418. 
Keciiir'>^lly  of  crosi»"»,  231. 
K«viinl.  jteological.  iinix-rfect,  25*. 
ItfQ^^'rr  on  tt\rn  destruying  cattle, 

67. 

n^-prod action,  rate  of,  56. 

ili-semlilanro  to  parents  in  mon- 
grels and  hybrid*    24i. 

Iteversion,  law  of  inh'Titance,  IS. 

in    pigeons   to    blue   colour, 

M* 

Uhododeu'iron,  sterility  of,  226 
Hu'lianl,  I'ruf.,  ••:>  Aspicarpa,  3 '6. 
llii'hardson,  Sir  J,,   on  structum 
of  siniirreln,  162. 


i 


I 


I    ' 


II 


452  ON  THE  ORIGIN  OF  SPECIES 


Rirli«rf|»nn.  Sir  J.,  on  flibna  of 
ttif  HotiiJiom  h^niiiiphere,  387. 

Robin i»,  (fr»n((  cf,  3:15. 

Rf>l»nt«,  Miriil,  124. 

Riiiliii'cntary  or^janii,  404. 

Rtidirr<TiUi  imjiorUnt  for  clMiii- 
flcAtion,  374. 

Ramirft  on  (jraftji,  J95. 

K«Irii()n«,      malM,     flKhtlng,     and 

>i<K>k«l  )«'Ts  iif,  so. 
Kalt-wHf^r,  how  far  fnjurloni  *o 

•»<e<l.t,  322. 
Saurcihagus  Rnlphurmtim,  IflS. 
Schi'vite  on  bliiid  tnsrcfji,  125. 
Schlpp-l  on  in.ikp(i,  130. 
Sfta-wai«T,   hcjw  far   Injurlonj   to 

»»>tHN,  822. 
Hebn^;lit,     .Sir     J.,     on     croaaed 

aniris.'tit,  \'ji. 

on  (M'lori  ion  of  plRBonn,  ?9. 

Sftdgwirk,     "ruf.,    on     grotips    of 

iip«rif>«  smi.lHiily  »pp«..iriii;;,  -jri. 
H<H'(llinK-!i    d««lr<iye<l    by   iriHPcU, 

fi3.  i 

S«p<li,  nntrlm'>tit  In,  71. 

winK"-d,  13:i. 

power  of  rraistinfj  na1t-w»t«r. 

822. 
in    crops   and    int^stinfs   of 

birdii.  8-.'5. 

eal.'n  by  flsh,  325,  847. 

in  rniiii,  .147. 

hookeil,  on  i<iland^,  352. 

H<»li»cti(jn   of   doraeatlc   prcxlucU, 

27. 
principle  not  of  recent  oriirin, 

31. 

nnroiisrlnin,  82. 

natural,  73. 

sexual.  79. 

natural,        circumstancM 

favourabl"  to,  92. 
H«xms.  ri*l«liotiii  of,  79. 
"Sexual  rhai.ii'f'Pt  variable,  148. 

■  s<>l>*<:'lion,  7!'. 

Shppp,  riipniio.  their  wlertinn,  29. 
two  «ut.-br><'d»  unintention- 
ally [irodurwd,  S3. 

tivjuntain,  varif  ties  of,  70. 

Shflls,  rnlouri  of,  120.  I 

littoral,    seldom    embedded.  1 


frPshwAter.  dispersal  of,  844. 

—  of  Mn.i";rs,  :<,VV 
land,  distribution  of.  S57. 


Silene,  fertility  of  cross**,  281. 
Hilliman,  Prof.,  on  blind  rat,  U5. 
.Sknils   of  young   mammals,    1T7, 

3'.*2. 
HlavumaVlne  Instinct,  104. 
Smith.  Col.  flamllton,  on  striped 

horses,  1 19. 

.Mr.    Kred.,  on  slaTe-making 

ant«i.  107, 

on  neuter  anU,  115. 

Mr.,  of  .loflin    Hill,  on  the 

de^riKlatioii  of  coaat-rocks,  254. 

Snap  draifon,  14«. 

Hotnerville,  lA^Txi,  on  selection  of 

shwj'p,  29. 
Sorbiis.  Krafts  of,  285. 
Hl«nie|,  King  Charles's  br«ed,  St. 
Sj^'i-H,  iMilymorj.hic,  48. 
— -  Common,  variable,  50. 

in  larffe  (fenera  variable,  51. 

groups  of,  sudcjenly  appear- 

inK, '.'71,  274. 

tieneath  8ilnrian  formattona, 

275. 

—  Bticcesslvely  appearing,  2<«). 

■      chanKtns      simultaneously 

throughout  the  world,  289. 
Spenrer,  Ixjrrl,  on  incrnaaa  in  alse 

"fr.1t tie,  .13. 
Sph.'x,  parasitic,  li»6. 
v^l  I'i.-rs,  development  of,  897. 
Spitzdog  crossed  with  fox,  240. 
.sports  in  plaiit.i,  9. 
Wprengel,  C.  <;.,  on  rrosiing,  89. 

"n  ray-rt<ir»'t8,  182. 

S<Iiiirrels,  jfradationa  in  stnjctnre. 

.stMt!ord.shira  heath,   changM  In, 

(■>'"i. 
.SU((-l)eetles,  flchting,  80. 
Sterility  from  chanired  oondlUona 

of  lifp.  K 

of  hybrids,  221. 

laws  of,  228. 

— causes  (.f,  28<». 

- —  from  unfavourable  conditions. 

23S. 

of  certain  varieties,  242. 

St.  Hf-lena,  productions  of,  850. 
St.  Hilaire,  Aug.,  on  cla.Hsiflcatlon, 

87'!. 
St.  John.   Mr     on  ha>^*ta  q'  sa.tJL 

K3.  " 

HttTiR  of  he>-,  1i!2. 
StfK-lis,    aboriginal,    of  domeatio 

aniinala,  18. 


INDEX 


463 


Btmu,  thlckoMi  of,  IB  BriUln. 

Strips  on  hortM,  14M. 
Htrncturw.  dejfr»*«  of  utility  of,  181. 
HtnigKle  for  •xliUnce,  68. 
Bn.  c«Mion,  Keologic*!,  280. 

Swallow,  on*  iptci^a  •nppUotlDs 

Mother,  70. 
SwlmbUddBr,  171. 
■•^Titam,  DAtoral,  872. 

Tail  of  girmffe.  175. 

of  »qn»tic»nimAU,  178. 

niiiimentary,  408. 

T»nj  deflciont,  122. 

Ttus,  ;i  on  mnbelliferotu  flowers. 
132.  ' 

Teelh  and  b»ir  correlated,  131. 

—  embryonic,  tracei  of,  in  birds. 
405. 

—  nidlm^ntary,    in    embrronic 
c»lf,  405,  432. 

T«K»tmfier,  Mr,  on  cell*  of  beM. 

204,  JIO 
r^-mminck  on  dliitribulion  aiding 

clamiiacation.  877. 
rhouln  on  graft*,  235. 
Thnuh,  aquatic  sprcips  of,  IM. 

mocking,  of  the   (ialai«go«, 

881. 

ronng  of,  .spotted,  3»5. 

—  nest  ,f,  21fc. 
ili'irft,  M..  on  cro»«ed  fii.-l,  233. 
Thwait*a,  .Mr.,  on  acclliii»lig»tion, 

1  -.'7. 
Ti'-rra  ilfl  Fi!p/.\  .lopn  of,  198. 

(ilanta  o'    .739,  342. 

T:rat»T -drift,  8j4. 

Time,  ls|<s«  of,  253. 

Tlmoiwe,  1«5. 

T  ..vii  on  i.sUndH,  353. 

r   ■.«CC(;,  crwia.  d  varie'iVii  of,  343 

TotnMi,  Mr.,  on  the  rii...iribntion  o' 

baU,  354. 
Tran.sitione  tn  Tarietica  nip»,  IS.'S.     i 
irerjion  iH!an<'«  belong  to  pecnliar  i 

ordert,  S."  2.  i 

With  !ieparat»i  wxoa,  00 

l>ifolnim  ).ra^>ti.ie,  88,  88. 

— ^—    inf*«rnatnni    §j 

Trigonia,  288.    ~' 
TriloblUNi,  275. 

siidilen  extinction  of,  288. 

Trogioilj-tea.  218. 


Tncntnca,  blind.  124. 
Tumbler  pifeona,  habiU  of,her*di- 
tary,  ly2. 

young  of,  400. 

Turkey-c^k,    brush    of   hair   on 

breaat,  82. 
Turkey,  naked  skin  on  head,  177. 

young,  wild,  \<\4, 

Turnip   and   caht)*^^,    analojrotm 

variatiiina  of,  144. 
Tyjw,  unity  of,  185. 
Types,    micceaalon    ot.    In    aaoia 

areas,  804. 

Udden  enlarged  by  nae,  11. 

rudimentary,  405. 

Ulex,  young  Inavns  of,  8S>5. 
Uml^lliferjp,    outer    and      inner 

florets  of,  131. 
Ututy  "f  type,  185. 
l-e,   effecU  of,  under  dommtlra. 

tion,  10. 
■  eflTecta  of.  In  a  state  of  natnrw, 

l'-'2. 
Utility,  how  fhr    mportant  in  the 

'•"nitructlon  of  »"arh  part,  179. 


Va.'nclennes  on  freshwater  fish. 

345. 
Variability  -of   mongrels  and    by. 

brids,  244. 
Variation  tinder  domettieatlon,  7. 

caused  by  reproductive  sy- 
stem being  ai!(»cte«l  by  conditions 
of  life,  8. 

under  nature,  41. 

- —   laws  of,  119. 

Vsriitions  appear  at  correspondlnit 

ak;es.  13,  81. 

analogous  In  distinct  speciee, 

144. 
Var;Ht!e«,  natural,  41. 

struggle  between,  69. 

domestic,  eititirtion  of.  102. 

transition*!,  rarity  of,  i.',.s. 

when  rr'.»».d.  'ertlle,  340. 

when     r   Hiiad,   -lenie,  242. 

classi^raf  ion     f.  S,HO. 

Verba«cum,  sUrilit)  of,  225. 
- —  varieties  of,  crosMej,  243. 
Verneuil,  M.  d»»,  on  thu  ouccoeslf-a 

Viola  tricolor,  «J8. 

Volcanic    islands,  denudation    of 

2.^5. 
Vulfire,  naked  skin  on  head,  177. 


I 


'  il 
i  1 


Wmdi 


4:,i 


ON  THE  ORIGIN  OF  SPECIES 


WiiiJinKbirdi,  847. 

Wallmce,  Mr.,  on  origin  of  •peelM, 

on  law  of  g6(  graphical  dis- 

tnbiitioo,  81U. 
'>n  the    MtlAj  Archipelago, 

SS5. 
Wa><ii,  Htiri;:  of,  182. 
Watwr,  frcMh,  productions  of,  844. 
Wat«T-li<<n,  I'iT. 
WaterhiitiM,    Mr.,    (<n    Aoatralian 

inanupiala,  106. 

on   Kr»«tly  developed    |iarta 

being  variable,  \M. 

on  thfl  c«11b  of  t)©*"!,  202. 

nti  general  affinities,  8»«. 

Wai4T.ou*el,  16<J. 

Watson,  Mr.  II.  C,  on  range  of 
varieties  of  Britiah  plants,  68. 

■ >n  arcliiiiatisation,  127. 

i,n  flora  of  Azores,  826. 

in  Alpine  plants,  830,  888. 

on     ranty   of    intermediate 

vaiieties,  15h. 
Weald,  denudation  of,  2,^. 
Web  of  fnet  In  water-birds,  IM. 
W»Ht  Indian  ialands,  mammals  of, 

Wegiwood  on  species  in  large 
^■enera  being  closely  allied  to 
others,  53. 

on  the  tarsi  of  Engid»,  142. 

on  Uia   antennie  of  hymen- 

opteroas  insectx,  874. 

Wlinal,  varietiea  of,  108. 
Wliite  Mountains,  flora  of,  828. 
Wings,  reduction  of  size,  122. 


Wings  of  Inaeeta  homologoua  with 
branchlK,  173. 

rudimentary,     in     inaactc, 

405. 

Wolf  croMMd  with  dog,  193. 

of  Falkland  Is.es,  858. 

WoUaston,    Mr.,   on   varietiM    of 

in<iects.  46. 

on   fosiiil    varietiea  of    land- 
shells  in  Madeira,  48. 

on  colours  of  insects  on  sea- 
shore, 120. 

on  wingles*  beetles,  123. 

on     rarity    of     intennediate 

varieties,  158. 

on  insular  insects,  840. 

on    lan'i-nhella  of    Madeira, 

natural  ii<e<i,  3>'>1. 

Wolves,  varieliei*  of,  88. 
\Vo<»dpeck9r,  habits  of,  IM. 

Kro«n  colour  of,  177. 

WiKxlwanl,  Mr.,  on  the  dnrmtion 

of  stmciflc  forms,  363. 

on  thecoTiiiiiunus  succaasioD 

of  genera,  284. 

-  on  the  succeasion  of  typea, 
304. 

World,    sitecles    changing    simul- 
taneously throughout,  380. 
Wrens,  neat  of,  21$. 

Youatt,  Mr.,  on  selection,  38. 

on  sub-breeds  of  (•'■•ep,  88. 

on    rudimentary    horns     in 

yoinig  cattle,  408. 

X«bn,  stripes  on,  147. 


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'^''■i^t^^:  '  '''f^-:^:^i^^0?^       -tA',^ 


The  World's  Classics 


List  of  Titles 


•a. 

•3. 

•4- 

5- 

•6. 

7- 
8. 

*9. 
•10. 

la. 
•«3. 


•15. 
16. 

«7- 
18. 

•19. 

ao. 
•ai. 

aa. 
•33- 

34. 

•as- 
a6. 

*aj. 
a8. 

ag. 

30. 

•31. 
•3a. 


Charlotte  Bront*i'«  Jane  Eyre.    Fourth  Impretsioo. 

Lamb's  Essays  of  Elia.     Fifth  Impression. 

Tennyson's  Poems.     Fifth  Impression. 

Goldsmith's  Vicar  of  Wakefield.    Third  Impression. 

HazUtt's  Table-Talk.     Third  Impression. 

Emerson's  Essays,  ist  and  and  .Scnes.  Fifth  Impression. 

Keats's  Poems.     Third  Impression. 

Dickens's  Oliver  Twist     Second  Impression. 

Barham's  Ingoldsby  Legends.    Third  Impression. 

EmUy  Bronte's  Wuthering  Heights.    Third  Imp. 

Darwin's  Origin  of  Species,     hourth  Impression. 

Bunyan's  Pilgrim's  Progress.     Second  Impression. 

EngUsh  Songs  and  Ballads.    Compiled  byT.  VV.  II 

Cropland.     Second  Impression. 
Charlotte  BrontiS's  Shirley.    Second  Imprcswoo. 
Hazlitt's  Sketches  and  Essays.    Third  Impressioa 
Herrlck's  Poems.     Second  Impression. 
Defoe's  Robinson  Crusoe.    Second  Impression. 
Pope's  Iliad  of  Homer.    Second  Impression. 
Carlyle's  Sartor  Resartus.    Third  Impression. 
Swift's  Gulliver's  Travels.     Second  Impression. 
Poe's  Tales  of  Mystery  and  Imagination.  Third  Imp. 
White's  History  of  Selbome.     Second  Impression. 
De  Quincey's  Opium  Eater.     Third  Impression. 
Bacon's  Essays.    Second  Impression. 
Hazlitt's  Winterslow.     Second  Impression. 
Hawthorne's  Scarlet  Letter.    Second  Impression. 
Macaulay's  Lays  of  Ancient  Rome.  Second  Impression. 
Thackeray's  Henry  Esmond.     Second  Impression. 
Scott's  Ivanhoe.     Second  Impression. 
Emerson's  English  Traits,  and  ReprcscutaUve  Men. 

Second  Impression. 
George  EUot's  MiU  on  the  Floss.    Third  Impression. 
Selected  English  Essays.     Chosen  and  Arram-ed  by 

W .  rsACOCK.     Third  Impression. 


'iiK^;^^  ^ 


Av^i-.-»  ---  - 


The  World's  Classics 


« ■■'  f.\ 


List  of  Titles  {coniinued) 

33.  Hume's  Essays.     Second  Impression. 

34.  Bums's  Poems.     5>econd  Impression. 

•35.  44.  51.  55.  64,  69,  74.     Gibbon's  Roman  Emplra 

Seven  Vols.     Vols.  I,  II,  Third  Imp,    III-V,  Second  Imp. 

•36.  Pope's  Odyssey  of  Homer.    Second  Imprestioo. 
•37.   Dryden's  Virgil.     Second  Imprewion. 
*38.  Dickens's  Tale  of  Two  Cities.    Third  Impretsion. 
*3g.  Longfellow's  Poems.     Vol.  I.     Second  Impressioa. 

40.  Sterne's  Tristram  Shandy.    Second  Impression. 

4i>  4S.  53.  Buckle's  History  of  Civilization  in  England. 
Three  Vols.     Second  Impression. 
•49,  56,  •76.  Chaucer's  Works.     From  the  Text  of  Prof. 

Skkat.     Three  Vols.     Vol.  I,  Second  Impretsion. 
•43.  Machiavelli's  The  Prince.  Translated  by  Luici  Ricci. 

45.  English  Prose  from  Mandevllle  to  Ruskin.    Chosen 

and  Arranged  by  W.  Peacock.     Second  Impression. 

46.  Essays  and  Letters  by  Leo  Tolstoy.    Translated  by 

Aylmer  Maude.     Second  Impression. 

47.  Charlotte  Bronte's  Villette.    Second  Impression. 

49.  A  Kempis's  Of  the  Imitation  of  Christ      Second 

Impression. 

50.  Thackeray's  Book  of  Snobs,  &c.    Second  Impression. 
5a.  Watts-Dunton'S  Aylwln.     .Second  Impression. 

54>  59  Adam  Smith's Wealthof  Nations.  Vol.],  sndliup. 

57.  Hazlitt's  Spirit  of  the  Age. 

58.  •137.  Robert  Browning's  Poems.    Vols.  I  and  II. 

60.  The  Thoughts  of  Marcus  Aurellus.     A  new  tiansla- 

tioa  by  John  Jackson. 

61.  Holmes's  Autocrat  of  the  Breakfast-Table.    Second 

Impression. 

6a.  Carlyle's  On  Heroes  and  Hero-Worship.     Second 
Imjiression. 

63.  George  Eliot's  Adam  Bcde.     Second  Impress! 00. 

65.  •70,  •77.  Montaigne's  Essays.   Florio's  trans.   3  Vols. 

66.  Elorrow's  Lavengra     Second  Impression. 


,.V?f 


mmmgm 


•75- 

•78. 

•79- 
»8o. 


The  World^s  Classics 

List  of  Titles  {continued) 

•67.  Anne  Brontii's  Tenant  of  WUdfeU  HaU. 
•68.  Thoreau'a  Walden.    Intro,  by  T.  Watts-Dunton 
•7>»  81  m-114.  Burke's  Works.  Six  Vols.  With  Preface,  br 

JuiJGB  Willis,  K.  W.  Kafkety,  and  F.  II.  Wi:  i  is. 
•7a.  Twenty-threeTalesbyTolstoy.  Tr.byL.and  A. Maude. 
•7:    Borrow's  Romany  Rye. 
Bomow's  Bible  in  Spain. 

^^y^  Br°P**'«  The  Profcttor,  and  the  Poems 
or C.,E.,and  A. Bronte.    Intro,  by T.Watts-Dunton. 
Sheridan's  Plays,    introduction  by  Joseph  Knight 
C^rge   EUot's   Silas   Marner,   The  Liiled  VdL 
Brother  Jacob.     Intro,  by  T.  Watts-Dunton 
•83.  Defoe's  Captain  Singleton.    With  an  Introduction  by 
Thkodork  Waits-Dunton.  ' 

♦83.  84.  Johnson's  Lives  of  the  Poets.    With  an  Introduc- 
tion by  Arthur  Wauch.     Two  Vols, 
•85.  Matthew  Arnolds  Poems.  1849-64.     With  an  Intro- 
duction by  A.  T.  QuiLLER-Coi;cH. 

•86.  Mrs.  GaskeU's  Mary  Barton.    With  an  Introduction  by 

C1.K11KNT  Shorter. 
•87.  Hood's  Poems.    Edited  by  Walter  Jerrold 

•88.  Mrs.  GaskeU's  Ruth.  With  an  Introduction  by  Clement 
Shorter. 

•89.  Holmes's  Professor  at  the  Breakfast-Table.     With 

an  Introduction  by  W.  Kubertson  Nicoll. 

•90.  Smollett's  Travels  through  France  and  Italy.   With 

an  Introduction  by  T.  Seccombe. 

•91,93-  Thackeray's I'endennis.  Intro,  by  E.  Gosse.  a  VoU. 
•93.  Bacon's  Advancement  of  Learning,  and  The  New 
Atlantis.     With  an  Introduction  by  pRorESSoR  Case. 
Scott's  Lives  of  the  Novelists.     With  an  Introduction 

by  AlTSTIN  DOBSON. 

Holmes's  Poet  at  the  Bi  eakfesUTublc.     With  an 
Imroiiuction  by  W.  Koberts-jn  Nicoll. 
•96-98.  Motley's  Rise  of  the  Dutch  Republic.    With  an 

Iniroductiou  by  Clement  Shorter,     Three  VoU. 

5 


•94- 
•95. 


The  World's  Classics 


List  of  Titles  {continued) 

•99-  Coleridge'*  Poem*.     Intro.  A.  T.  Quiixer-Couch. 
100-108.   Shakespeare's  Plays  and  Poems.     Edited  by 
rHEODORK  VVatts-Dunton,  With  a  Preface  by  Alger- 
non CharlesSwinburne.    NineVoU.     In  frtfareaion. 

•109.  George  Herbert's  Poems.  With  an  Introdncuon  by 
Arthi'r  Wacgh. 

•uo.  Mrs  GaskeU'8  Cranford.The  Moorland  Cottage,  ftc 
>\  ith  an  Introduction  by  Clement  Shorter. 

•115-  Essays  and  Sketches  by  Leigh  Htmt  With  ui 
Introduction  by  k.  Hrimlry  JoiiNhON. 

•116.  Sophocles.  The  Seven  Plays.  Tramlatcd  into  English 
Verse  by  Professor  Lewis  Campbell. 

•117-  Aeschylus.  The  Seven  Plays.  Translated  into  English 
Verse  by  Profeasor  Lewis  Campbell. 

•118.  Horae  Subsedvae.  By  Dr.  John  Brown.  With  an 
Intro<inction  by  AUSTIN  Dobson. 

•UQ.  Cobbolds  Margaret  Catchpolo.  With  an  Introduction 
by  Clement  Shortkr. 

•lao,  131.  Dickens's  Pickwick  Papers,    in  Two  Vols. 

•132.  Mrs.  Caudle's  Curtain  Lectures,  and  other  Stories 
and  Essays  by  Dolglas  Jerrold.  With  an  Intro- 
duction by  Walter  Jerrold,  and  90  Illustrations. 

•133.  Goldsmith's  Poems.    Edited  by  Austin  Dobson. 

•134.  Hazlitt's  Lectures  on  the  EngUsh  Comic  Writers. 
With  an  Introduction  by  K.  Primley  Johnson. 

•135, 136.  Carlyle's  French  Revolution.  With  an  Intro- 
duction  by  C.  K.  L.  Fi  etcher.     Two  Vols 

•137.  Home's  New  Spirit  of  the  Age.  W  ith  an  Intro- 
duction  by  Walter  Ikrrdid. 

•138.  Dickens's  Great  ExpectaUons.    VN  ith  6  Ulustration. 

by  Warwick  Gohle. 
•139.  Jane    Austen's  Emma.    Intro.  E.  V.  Lucas. 
•130,  131.  Don  Quixote.    Jcrvas's  trtinsla'ion.    With  Intro,  and 

Notes  by  J.  Kitzmalrice-Kelly.     Two  Vols 
•232.  Leigh  Hunt's  The  Town.     W  uh  an  Introduction  and 

Notes  by  Austin  Dr)B;,oN.  and  a  Frontispiece 
•133.  Palgiuvc's  Golden  Treasury,  with  additional  Poem.. 

6 


The  World's  Classics 


List  of  Titles  {continued) 
•134-  Artetophane*.    Frere's  tranmUtion  of  the  Achar- 

niana,  Knightm,  Bird*,  and  FrofiL    With  an  Intro- 

dnctiOD  by  \V.  W.  Mkrry. 
•135  Marlowe 8  Dr.  Faustus,  and  Goethea  Faust.  Part  I 

(Ansters  translation).     Intio.  by  A.  W.  WAatt 
•136.  BnUer't  Analogy.    Ed.  W.  E.Gladstoni 
•137.  Browninr'i  Poena.      Vol.   II   (Dramatic   Lyric,  and 

RomancM,  .Men  and  Women,  and  Dramatis  Personac) 
•138.  Cowper-s  Lcttere.     Seleaed.  with  .n  Introduction,  by 

fc.  V .  Lucas.  ' 

•139.  Gibbon's  Autobiography.  With  Intro,  by  T.  B.  Buky 
•140.  TroUope'.  The  Three  Clerk..    W.th  «.  Introdnctfon 

by  \\.    IKIGNMC'JTH  .SHORE. 

•141.  Anne  Bronte's  Agnes  Grey. 

•14a.  Fieldlng^i  Journal  of  a  Voyage  to  Lisbon.    With 

•,^0  A  t'°"/v  i:!L^J'  i"'"""*  ^«»s»''.  *«d  >  Illuitration*. 
•143.  A  True  Vagabond-Poet  (Charles  Wells).    By  Thko- 

DORS  .^^^JTS-DUNTON.  With  the  complete  text  of 
Joseph  and  his  Brethren  '  and  an  Introductory  Essay  by 

Algernon  Charles  Swinbl-rne.  i^tdrh  Riadi 

•144.  Carlyle's  Life  of  John  Sterling.     With  an  Inti" 

duction  by  W.  Hai.e      hite. 

^S^'\^*?*™*  "«*  L»"««'  »od  The  Ethics  of 
the  Dust     koskin  House  ediUon.  ^^ 

^r?!S^'"  J*^  ?f  **  '^****'  *°^  The  Crown  of  WUd 
UUve.     Knskin  House  edition. 

^^V**^°'o^  J°y  **  ^^"''  "d  The  Two  Paths. 

Kuskin  House  edition.  ^^ 

Ruskin's  Unto  this  Last,  and  Muneni   Pulveris. 
Ruskin  House  edition. 
•149.  Reynolds's   Discourses.    Intro.  Austin  Dobson 
•150.  Washington  Irving's  Conquest  of  Granada.    Intro 
by  GEKTRruE  Atherton.  Inpreparaticli 

•151.  15a.  L«age;s  GU  Bias  (Smollett  s  translation).     Intro. 

andNotrsbyJ.    K!T7MAI-.H!CEKeLLV.      Tw.  Vol, 

•153-  Carlyle's  Past  and  Present.    Intro,  by  G.  K  Ches- 
TKRTON.  Ntarlv  h  mdv 

Othtr  volumes  in  prtparati^n. 

1 


•'45 
•146. 
•147. 
•148. 


:  <=c-/,r-=#=^^.=-; 


If 


The  Boys*  Classic} 

Pott  8vo  (sue  6x4  Inches) 

CLOTH I/,  r 

SULTAN-RED   LEATHER,  limp, 

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I.  The  Captain  of  the  Guard.    B/  James  Gkant. 
B.  Bfr.  Midshipman  Easy.    Hy  Captain  Marryat. 

3.  The  Scottish  Chleb.    By  Jane  Porter. 

4.  The  Tower  of  London.  By  W.  Harrison  Ainswor 

5.  The  Last  of  the  Mohicans.    By  J.  Fsnimorb  Coor 

6.  Robinson  Crusoe.    By  Daniel  Defoe. 

7.  The  King's  Own.    By  Captain  Marryat.    Will 

Illustration!  by  Warwick  Goble. 

8.  Harold.      By  Lord  Lytton.     With  6  Illastrationi 

Charles  Burton. 
g.  The  Rifle  Rangers.    By  Captain  Maynb  Reid.    V 

6  Uluftrmtioni  by  J.  E.  Sutcliffe. 
10.  The  Scalp  Hunters.    By  Captain  Maynb  Reid.   V 

6  Illastrationi  by  A.  H.  Collins. 
n.  Captain  Singleton.    By  Daniel  Dbfob.    With  6  U 

tratiooi  by  Warwick  Goble. 

Othtr  volunus  in  prtparation. 


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ti.  To  hold  100  Volumes,  World's  Classics  size. 

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able  shelves,  best  cabinet  make.     Size  44  x  36  x  6  inc 
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8 


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