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THE 


DESCENT  OE  MAN, 


AND 


SELECTION   IN   RELATION  TO   SEX. 


CHAKLES  DARWIN,  M.  A.,  R  R.  S.,  Etc. 


WITH  ILLUSTRATIONS. 


IN  TWO  VOLUMES.— Vol.  I. 


NEW    YORK: 

D.     APPLETON"     AND     COMPANY, 

549   &  551   BEOADWAY. 

1871. 


Works  of  Charles  Darwin, 


D.  APPLETON   &  COMPANY 

Have  just  published  a  new  edition  of 

THE   ORIGIN  OF   SPECIES, 

BY  MEANS   OF  NATUEAL  SELECTION. 


A  NEW  American  edition  of  "  The  Origin  of  Species,"  later 
than  the  latest  English  edition,  has  just  been  published,  with 
the  author's  most  recent  corrections  and  additions. 

In  the  whole  history  of  the  progress  of  knowledge  there 
is  no  case  so  remarkable  of  a  system  of  doctrines,  at  first 
generally  condemned  as  false  and  absurd,  coming  into  gen- 
eral acceptance  in  the  scientific  world  in  a  single  decade.  The 
views  of  Mr.  DARwnsr  wiU  undoubtedly  undergo  both  modifica- 
tion and  extension  in  the  future,  but  in  their  broad  scope  they 
are  not  only  extensively  assented  to,  but  they  are  guiding  the 
researches  of  the  foremost  scientific  minds  of  the  world.  From 
the  following  statements,  the  reader  will  infer  the  estimate 
that  is  now  placed  upon  the  man  and  his  works  by  the  highest 
authorities. 

The  great  law  of  "  Natural  Selection  "  was  independently  dis- 
covered by  Mr.  Alfred  Russell  Wallace,  an  eminent  English 
naturalist.  He  has  lately  published  a  work  upon  this  subject, 
and  in  its  preface  he  pays  the  following  tribute  to  the  author 
of  the  "  Origin  of  Species  :  " 

"  The  present  work  will,  I  ventm-e  to  think,  prove  that  I 
both  saw,  at  the  time,  the  value  and  scope  of  the  law  which  I 
had  discovered,  and  have  since  been  able  to  apply  it  to  some 
purpose  in  a  few  original  lines  of  investigation.     But  here  my 


)t  D,  Apptetori  tfe  C&mpdnyU  hAlkaiimi. 


daitti^  cease.  I  have  felt  all  ffiv  life^  and  I  still  feel,  the  most 
sincere  satisfaction  tliat  Mr.  Darwin  had  been  at  work  long  be- 
fore me,  and  that  it  was  not  left  for  me  to  attempt  to  write 
the  '  Origin  of  Species.'  I  have  long  since  measured  ray  own 
strength,  and  know  well  that  it  would  be  quite  unequal  to  that 
task.  Far  abler  men  than  myself  may  confess  that  they  have 
not  that  untiring  patience  in  accumulating,  and  that  wonder- 
ful skill  in  using,  large  masses  of  facts  of  the  most  varied  kind 
— ^that  wide  and  accurate  physiological  knowledge — that  acute- 
ness  in  devising,  that  skill  in  carrying  out  experiments, 
and  that  admirable  style  of  composition,  at  once  clear,  persua- 
sive, and  judicial,  qualities  which,  in  their  harmonious  combi- 
nation, mark  out  Mr.  Darwin  as  the  man,  perhaps  of  all  men 
now  living,  best  fitted  for  the  great  work  he  has  undertaken 
and  accomphshed." 

Prof.  T.  H.  Huxley  says :  "  We  do  not  speak  jestingly  in 
saying  that  it  is  Mr.  Darwi«'s  misfortune  to  know  more  about 
the  question  he  has  taken  up  than  any  man  living.  Personally 
and  practically  exercised  in  zoology,  in  minute  anatomy,  in  ge- 
ology ;  a  student  of  geographical  distribution,  not  on  maps  and 
in  museums  only,  but  by  long  voyages  and  laborious  collection ; 
having  largely  advanced  each  of  these  branches  of  science,  and 
having  spent  many  years  in  gathering  and  sifting  materials  for 
his  present  work,  the  store  of  accurately-registered  facts  upon 
which  the  author  of  the  '  Origin  of  Species '  is  able  to  draw  at 
will  is  prodigious." 

An  interesting  example  of  the  change  of  opinion  upon  this 
subject  among  the  scientific  men  of  England  is  furnished  by 
Sir  Charles  Ltell — perhaps  the  most  learned  of  living  geolo- 
gists, and  who  has  powerfully  contributed  to  give  that  science 
its  present  shape  and  direction.  After  having  studied  for  fifty 
years  the  subject  of  life  in  connection  with  the  past  changes 
of  the  globe,  and  embodied  the  older  views  in  all  his  numerous 
works,  he  has  at  length,  in  tlie  tenth  edition  of  his  "  Principles 
of  Geology,"  abandoned  the  old  ground  as  untenable,  and 
fidopted  the  views  represented  by  Mr.  Darwin. 


A  Apptiton  cfe  Oompttnp^s  PuhUcaihni. 


In  ttig  eountry  there  bas  been  a  less  ready  acceptance  of 
these  ideas ;  but  at  the  last  meeting  of  the  American  Associa- 
tion for  the  Advancement  of  Science,  held  at  Troy,  Darwin's 
views  figured  prominently.  Prof.  Meehaos^  read  a  paper  on  one 
branch  of  Darwin's  researches,  in  which  he  had  at  first  supposed 
him  in  error,  but  at  last  found  him  to  be  right.  In  the  subse- 
quent discussion,  Dr.  Gray,  the  distinguished  American  bota- 
nist, declared  that  "  he  had  frequently  attempted  to  catch  Dar- 
win tripping  in  this  particular,  and  had  referred  to  him  many 
instances  vrhich  he  himself  at  the  time  considered  opposed 
to  the  theory ;  but  in  every  case  he  had  been  forced  to  with- 
draw his  objection." 

In  Germany  these  views  are  also  rapidly  extending.  They 
are  prominently  discussed  at  all  the  scientific  conventions,  and 
it  is  said  they  have  been  accepted  much  more  cordially  and  un- 
qualifiedly there  than  in  England. 

Prof.  GiEKiE,  a  distinguished  British  geologist,  attended 
the  recent  Congress  of  German  Naturalists  and  Physicians,  at 
Innsbruck,  in  which  some  eight  hundred  savants  were  present, 
and  he  thus  describes  the  relation  of  the  mind  of  Germany  to 
the  views  of  the  great  English  naturalist : 

"  What  specially  struck  me  was  the  universal  sway  which 
the  writings  of  Darwin  now  exercise  over  the  German  mind. 
You  see  it  on  every  side,  in  private  conversation,  in  printed 
papers,  in  all  the  many  sections  into  which  such  a  meeting  as 
that  at  Innsbruck  divides.  Darwin's  name  is  often  mentioned, 
and  always  with  the  profoundest  veneration.  But  even  where 
no  allusion  is  specially  made  to  him,  nay,  even  more  markedly, 
where  such  allusion  is  absent,  we  see  how  thoroughly  his  doc- 
trines have  permeated  the  scientific  mind,  even  in  those  depart- 
ments of  knowledge  which  might  seem  at  first  sight  to  be  far- 
thest from  natural  history.  '  You  are  still  discussing  in  Eng- 
land,' said  a  German  friend  to  me,  '  whether  or  not  the  theory 
of  Darwin  can  be  true.  We  have  got  a  long  way  beyond  that 
here.  His  theory  is  now  our  common  starting-point.'  And^ 
so  far  as  my  expereince  went,  I  found  it  to  be  so." 


D.  Appleton  &  Oompamy's  Publications. 


Dr.  Fritz  Muller,  an  eminent  German  naturalist,  has  sub- 
jected Darwin's  doctrines  to  a  critical  test  in  their  application 
to  the  development  of  the  Crustacea.  In  his  German  work 
upon  the  subject,  Avhich  bears  so  powerfully  in  favor  of  the  new 
views  that  it  has  been  republished  in  England  under  the  sug- 
gestive title  of  "  Facts  for  Darwin,"  Dr.  Mliller  says :  "  A  false 
supposition,  when  the  consequences  proceeding  from  it  are  fol- 
lowed further  and  further,  will  sooner  or  later  tend  to  absurdi- 
ties and  palpable  contradictions.  During  the  period  of  tor- 
menting doubt — and  this  was  by  no  means  a  short  one — when 
the  pointer  of  the  scale  oscillated  before  me  in  perfect  uncer- 
tainty between  the  pro  and  the  con,  and  when  any  fact  tending 
to  a  quick  decision  would  have  been  most  welcome  to  me,  I 
took  no  small  pains  to  detect  some  such  contradictions  among 
the  inferences,  as  to  the  class  of  Crustacea,  furnished  by  the 
Darwinian  theory.  But  I  found  none  either  then  or  subse- 
quently. Those  which  I  thought  I  had  found  were  dispelled 
on  closer  consideration,  or  eventually  became  converted  into 
supports  for  Darwin's  theory," 

Another  example.  In  1859,  Prof.  Gegenbauer  published 
the  "  Outlines  of  Comparative  Anatomy,"  which  has  been 
adopted  as  an  authoritative  text-book  of  the  subject.  He  has 
this  year  issued  a  second  and  much  enlarged  edition,  recast, 
and  embodying  the  Darwinian  philosophy.  He  speaks  of  the 
theory  of  descent  with  modification,  through  natural  selection, 
as  constituting  a  more  important  era  in  comparative  anatomy 
than  any  other  theory  has  ever  yet  done ;  and  he  regards  com- 
parative anatomy  itself  as  one  of  the  touchstones  of  its  truth. 
Dr.  Gegenbauer  closes  his  sketch  of  the  theories  of  the  subject 
with  the  following  words :  "  If  we  consider  that  the  number 
of  those  who  have  mastered  the  theory  and  its  real  meanings 
and  bearing  is,  though  at  present  small,  yet  constantly  increas- 
ing, and  that,  too,  by  accessions  from  the  ranks  of  its  former 
opponents,  we  begin  to  feel  ourselves  justified  in  looking  for 
the  accomplishment  of  an  auspicious  revolution  by  its  means." 


w  /    -_>/  I  (Xo/^^t ..  ^,. 


i 


COT^TENTS 


Introduction, Page  1 

PAET  I. 

THE  DESCENT   OB    ORIGIN   OF  MAN. 
CHAPTER  I, 

THE  EVIDENCE   OF  THE   DESCENT   OF   MAN   FROM  SOME   LOWEE  FORM. 

Nature  of  the  Evidence  bearing  o\i  the  Origin  of  Man.— Homologous  struct- 
ures in  Man  and  the  Lower  Animals. — Miscellaneous  Points  of  Corre- 
spondence.— Development. — Eudimentary  Structures,  Muscle.'*,  Sense- 
organs,  Hair,  Bones,  Reproductive  Organs,  etc.— The  Bearing  of  these 
three  great  Classes  of  Facts  on  the  Origin  of  Man,       .        .        .    p.  9 

CHAPTER  II. 

COMPAKISON   OF   THE   MENTAL   POWERS    OF   MA^  AND   THE    LOWER   ANIMALS. 

The  Difference  in  Mental  Power  between  the  Highest  Ape  and  the  Lowest 
Savage,  immense. — Certain  Instincts  in  common. — The  Emotions. — 
Curiosity. — Imitation. — Attention. — Memory. — Imagination. — Reason. 
— ^Progressive  Improvement.— Tools  and  Weapons  used  by  Animals. 
— ^Language. — Self-Consciousness. — Sense  of  Beauty.— Belief  in  God, 
Spiritual  Agencies,  Superstitions, p.  33 

CHAPTER  III. 

COMPARISON   OF   THE   MENTAL   POWERS   OF  MAN  AND   THE   LOWER   ANIMALS — 

continued. 

The  Moral  Sense.— Fundamental  Proposition.— The  Qualities  of  Social 
Animals.- Origin  of  Sociability.— Struggle  between  Opposed  In- 
stincts.— Man  a  Social  Animal.— The  more  enduring  Social  Instincts 
conquer  other  less  Persistent  Instincts.— The  Social  Virtues  alone  re- 


CONTENTS. 

garded  by  Savages. — The  Self-regarding  Virtues  acquired  at  a  Later 
Stage  of  Development. — The  Importance  of  the  Judgment  of  the 
Members  of  the  same  Community  on  Conduct. — Transmission  of 
Moral  Tendencies. — Summary, page  67 


CHAPTER  IV. 

ON  THE  MANNER  OF  DEVELOPMENT  OF  MAN  FEOM  SOME  LOWEB  FOBM. 

Variability  of  Body  and  Mind  in  Man. — Inheritance. — Causes  of  Varia- 
bility.— Laws  of  Variation  the  same  in  Man  as  in  the  Lower  Animals. 
— Direct  Action  of  the  Conditions  of  Life. — Effects  of  the  Increased 
Use  and  Disuse  of  Parts. — Arrested  Development. — Reversion. — Cor- 
related Variation. — Rate  of  Increase. — Checks  to  Increase. — Natural 
Selection. — Man  the  most  Dominant  Animal  in  the  World. — Impor- 
tance of  his  Corporeal  Structure. — The  Causes  which  have  led  to  his 
becoming  erect. — Consequent  Changes  of  Structure. — Decrease  in 
Size  of  the  Canine  Teeth. — Increased  Size  and  Altered  Shape  of  the 
Skull. — Nakedness. — Absence  of  a  Tail. — Defenceless  Condition  of 
Alan, p.  103 


CHAPTER  V. 

ON  THE   DEVELOPMENT  OF  THE   INTELLECTUAL  AND   MORAL  FACULTIES 
DURING    PRIMEVAL   AND    CIVILIZED    TIMES. 

The  Advancement  of  the  Intellectual  Powers  through  Natural  Selection. — 
Importance  of  Imitation. — Social  and  Moral  Faculties. — Their  Develop- 
ment within  the  Limits  of  the  same  Tribe. — Natural  Selection  as  af- 
fecting Civilized  Nations. — Evidence  that  Civilized  Nations  were  once 
barbarous, p.  152 


CHAPTER  VL 

ON  THE   AFFINITIES  AND   GENEALOOT    OF    MAN. 

Position  of  Man  in  the  Animal  Series. — The  Natural  System  genealogical. 
— Adaptive  Characters  of  Slight  Value. — Various  Small  Points  of  Re- 
semblance between  Man  and  the  Quadruinana. — Rank  of  Man  in  the 
Natural  System. — Birtliplace  and  Antiquity  of  Man. — Absence  of 
Fossil  Connecting-links. — Lower  Stages  in  tlie  Genealogy  of  Man,  as 
inferred,  firstly  from  his  Affinities  and  secondly  from  his  Structure. — 
Early  Androgynous  Condition  of  the  Vertebrata. — Conclusion,    p.  178 


CONTENTS.  V 

CHAPTER  VII. 

ON    THE   RACES   OF   MAN. 

The  Nature  and  Value  of  Specific  Characters. — Application  to  the  Eaces 
of  Man. — Arguments  in  favor  of,  and  opposed  to,  ranking  the  So- 
oalled  Eaces  of  Man  as  Distinct  Species. — Sub-species. — Monogenists 
and  Polygeniats. — Convergence  of  Character. — Numerous  Points  of 
Eesemblance  in  Body  and  Mind  between  the  most  Distinct  Eaces  of 
Man. — The  State  of  Man  when  he  first  spread  over  the  Earth. — Each 
Eace  not  descended  from  a  Single  Pair. — The  Extinction  of  Eaces. — 
The  Formation  of  Eaces. — The  Efifects  of  Crossing. — Slight  Influence 
of  the  Direct  Action  of  the  Conditions  of  Life. — Slight  or  no  Influence 
of  Natural  Selection. — Sexual  Selection,        ....    page  206 


PAET  II. 

SEXUAL   SELECTION. 
CHAPTER  VIII. 

PEINCIPLES    OF   SEXUAL   SELECTION. 

Secondary  Sexual  Characters.  —  Sexual  Selection. — Manner  of  Action. — 
Excess  of  Males. — Polygamy. —  The  Male  alone  generally  modified 
through  Sexual  Selection. — Eagerness  of  the  Male. — Variability  of 
the  Male. — Choice  exerted  by  the  Female. — Sexual  compared  with 
Natural  Selection. — Inheritance,  at  Corresponding  Periods  of  Life,  at 
Corresponding  Seasons  of  the  Year,  and  as  limited  by  Sex. — Relations 
between  the  Several  Forms  of  Inheritance. — Causes  why  one  Sex  and 
the  Young  are  not  modified  through  Sexual  Selection. — Supplement  on 
the  Proportional  Numbers  of  the  two  Sexes  throughout  the  Animal 
Kingdom. — On  the  Limitation  of  the  Numbers  of  the  two  Sexes 
through  Natural  Selection,  .......     p.  245 

CHAPTER  IX. 

BECONDAET   8EXTJAL  CHARACTERS  IN  THE   LOWER   GLASSES   OF  THE  ANIMAL 
KINGDOM. 

These  Characters  absent  in  the  Lowest  Classes. — Brilliant  Colors. — Mol- 
lusca. — Annelids. — Crustacea,  Secondary  Sexual  Cliaracters  strongly 
developed;  Dimorphism;  Color;  Characters  not  acquired  before 
Maturity. — Spiders,  Sexual  Colors  of;  Stridulation  by  the  Males. — 
Myilapoda, p.  312 


vi  CONTENTS. 

CHAPTER  X. 

SECONDARY    SEXUAL    CHAEACTERS    OF    INSECTS. 

Diversified  Structures  possessed  by  the  Males  for  seizing  the  Females. — 
Differences  between  the  Sexes,  of  which  the  Meaning  is  not  under- 
stood.— Difference  in  Size  between  the  Sexes. — Thysanura. — Dijftera. 
— Hemiptera. — Ilomoptera,  Musical  Powers  possessed  by  the  Males 
alone. — Orthoptera,  Musical  Instruments  of  the  Males,  much  diversi- 
fied in  Structure  ;  Pugnacity  ;  Colors. — Neuroptera,  Sexual  Diflerences 
in  Color. — Hymenoptera,  Pugnacity  and  Colors. ^Coleoptera,  Colors  ; 
furnished  with  Great  Horns,  apparently  as  an  Ornament ;  Battles ; 
Stridulating  Organs  generally  common  to  Both  Sexes,        ,     page  831 

CHAPTER  XI. 

INSECTS,  continued. — order  lepidoptera. 

Courtship  of  Butterflies. —  Battles. —  Ticking  Noise. — Colors  common  to 
Both  Sexes,  or  more  brilliant  in  the  Males. — Examples. — Not  due  to 
the  Direct  Action  of  the  Conditions  of  Life. — Colors  adapted  for  Pro- 
tection.— Colors  of  Moths. — Display. — Perceptive  Powers  of  the  Lepi- 
doptera.— Variability. — Causes  of  the  Difference  in  Color  between 
the  Males  and  Females. — Mimicry,  Female  Butterflies  more  brilliantly 
colored  than  the  Males. —  Bright  Colors  of  Caterpillars. — Summary 
and  Concluding  Remarks  on  the  Secondary  Sexual  Characters  of  In- 
Bects, — Birds  and  Insects  compared,      .  ....    p.  374 


INTRODUCTION. 


The  nature  of  the  following  work  will  be  best  under- 
stood by  a  brief  account  of  liow  it  came  to  be  written. 
During  many  years  I  collected  notes  on  the  origin  or 
descent  of  man,  without  any  intention  of  publishing  on 
the  subject,  but  rather  with  the  determination  not  to 
publish,  as  I  thought  that  I  should  thus  only  add  to 
the  prejudices  against  my  views.  It  seemed  to  me  suffi- 
cient to  indicate,  in  the  first  edition  of  my  '  Origin  of 
Species,'  that  by  this  work  "  light  would  be  thrown  on 
the  origin  of  man  and  his  history ; "  and  this  implies 
that  man  must  be  included  with  other  organic  beings  in 
any  general  conclusion  respecting  his  manner  of  appear- 
ance on  this  earth.  Now  the  case  wears  a  wholly  dit- 
ferent  aspect.  When  a  naturalist  like  Carl  Vogt  ven- 
tures to  say  in  his  address  as  President  of  the  ISTational 
Institution  of  Geneva  (1869),  "personne,  en  Europe 
au  moins,  n'ose  plus  soutenir  la  creation  independante 
et  de  toutes  pieces,  des  especes,"  it  is  manifest  that  at 


2  INTRODUCTION. 

least  a  large  number  of  naturalists  must  admit  that 
species  are  the  modified  descendants  of  other  species ; 
and  this  especially  holds  good  with  the  younger  and 
rising  naturalists.  The  greater  number  accept  the 
agency  of  natural  selection  ;  though  some  urge,  whether 
with  justice  the  future  must  decide,  that  I  have  greatly 
overrated  its  importance.  Of  the  older  and  honored 
chiefs  in  natural  science,  many  unfortunately  are  still 
opposed  to  evolution  in  every  form. 

In  consequence  of  the  views  now  adopted  by  most 
naturalists,  and  which  will  ultimately,  as  in  every  other 
case,  be  followed  by  other  men,  I  have  been  led  to  put 
together  my  notes,  so  as  to  see  how  far  the  general 
conclusions  arrived  at  in  my  former  works  were  appli- 
cable to  man.  This  seemed  all  the  more  desirable 
as  I  had  never  deliberately  applied  these  views  to  a 
species  taken  singly.  When  we  confine  our  attention 
to  any  one  form,  we  are  deprived  of  the  weighty  argu- 
ments derived  from  the  nature  of  the  aflinities  which 
connect  together  whole  groups  of  organisms — their  geo- 
graphical distribution  in  past  and  present  times,  and 
their  geological  succession.  The  homological  structure, 
embryological  development,  and  rudimentary  organs  of 
a  species,  whether  it  be  man  or  any  other  animal,  to 
which  our  attention  may  be  directed,  remain  to  be  con- 

• 

sidered ;  but  these  great  classes  of  facts  afford,  as  it 
appears  to  me,  ample  and  conclusive  evidence  in  favor 
of  the  principle  of  gradual  evolution.     The  strong  sup- 


INTRODUCTION.  3 

port  derived  from  the  other  arguments  shoidd,  however, 
always  be  kept  before  the  mind. 

The  sole  object  of  this  work  is  to  consider,  firstly, 
whether  man,  like  every  other  species,  is  descended 
from  some  preexisting  form ;  secondly,  the  manner  of 
his  development ;  and  thirdly,  the  value  of  the  diflfer- 
ences  between  the  so-called  races  of  man.  As  I  shall 
confine  myself  to  these  points,  it  will  not  be  necessary 
to  describe  in  detail  the  difierences  between  the  several 
races — an  enormous  subject,  which  has  been  fully  dis- 
cussed in  many  valuable  works.  The  high  antiquity  of 
man  has  recently  been  demonstrated  by  the  labors 
of  a  host  of  eminent  men,  beginning  with  M.  Boucher 
de  Perthes ;  and  this  is  the  indispensable  basis  for 
understanding  his  origin.  I  shall,  therefore,  take  this 
conclusion  for  granted,  and  may  refer  my  readers  to 
the  admirable  treatises  of  Sir  Charles  Lyell,  Sir  John 
Lubbock,  and  others.  I^Tor  shall  I  ha\e  occasion  to  do 
more  than  to  allude  to  the  amount  of  difi*erence  between 
man  and  the  anthropomorphous  aj)es ;  for  Prof.  Huxley, 
in  the  opinion  of  most  competent  judges,  has  conclu- 
sively shown  that  in  every  single  visible  character  man 
difl:ers  less  from  the  higher  apes  than  these  do  from  the 
lower  members  of  the  same  order  of  Primates. 

This  work  contains  hardly  any  original  facts  in 
regard  to  man ;  but,  as  the  conclusions  at  which  I 
arrived,  after  drawing  up  a  rough  draft,  appeared  to 
me   interesting,  I    thought  that   they   might   interest 


4  INTRODUCTION. 

others.  It  has  often  and  confidently  been  asserted,  that 
man's  origin  can  never  be  known  :  but  ignorance  more 
frequently  begets  confidence  than  does  knowledge  :  it  is 
those  who  know  little,  and  not  those  who  know  much, 
who  so  positively  assert  that  this  or  that  problem  will 
never  be  solved  by  science.  The  conclusion  that  man  is 
the  co-descendant  with  other  species  of  some  ancient, 
lower,  and  extinct  form,  is  not  in  any  degree  new.  La- 
marck long  ago  came  to  this  conclusion,  which  has  lately 
been  maintained  by  several  eminent  naturalists  and 
philosophers ;  for  instance,  by  Wallace,  Huxley,  Lyell, 
Yogt,  Lubbock,  Biichner,  E-olle,  etc.,'  and  especially  by 
Hackel.  This  last  naturalist,  besides  his  great  work, 
'Generelle  Morphologic'  (1866),  has  recently  (1868, 
with  a  second  edit.  1870)  published  his  '  JSTatiirliche 
Schopfungsgeschichte,'  in  which  he  fully  discusses  the 
genealogy  of  man.     If  this  work  had  appeared  before 

'  As  the  works  of  the  first-named  authors  are  so  well  known,  I  need 
not  give  the  titles ;  but,  as  those  of  the  latter  are  less  well  known  in 
England,  I  will  give  them :  '  Sechs  Vorlesungen  iiber  die  Darwin'sche 
Theorie : '  zwiete  Auflage,  1868,  von  Dr.  L.  Biichner ;  translated  into 
French  under  the  title  'Conferences  sur  la  Theorie  Darwinienne,'  1869. 
'Der  Mensch,  im  Lichte  der  Darwin'sche  Lehre,'  1865,  von  Dr.  F.  Rolle. 
I  will  not  attempt  to  give  references  to  all  the  authors  who  have  taken 
the  same  side  of  the  question.  Thus  G.  Canestrini  has  published  ('  An- 
nuario  della  Soc.  d.  Nat.,'  Modcna,  1867,  p.  81)  a  very  curious  paper  on 
rudimentary  characters,  as  bearing  on  the  origin  of  man.  Another  work 
has  (1869)  been  published  by  Dr.  Barrago  Francesco,  bearing  in  Italian 
the  title  of  "  Man,  made  in  the  image  of  God,  was  also  made  in  the  image 
of  the  ape." 


INTRODUCTION.  5 

mj  essay  had  been  wi'itten,  I  should  probably  never 
have  completed  it.  Almost  all  the  conclusions  at  which 
I  have  arrived  I  find  confirmed  by  this  naturalist,  whose 
knowledge  on  many  points  is  much  fuller  than  mine. 
Wherever  I  have  added  any  fact  or  view  from  Prof. 
Hackel's  writings,  I  give  his  authority  in  the  text,  other 
statements  I  leave  as  they  originally  stood  in  my  manu- 
script, occasionally  giving  in  the  foot-notes  references 
to  his  works,  as  a  confirmation  of  the  more  doubtfal  or 
interesting  points. 

During  many  years  it  has  seemed  to  me  highly 
probable  that  sexual  selection  has  played  an  important 
part  in  differentiating  the  races  of  man;  but  in  my 
'  Origin  of  Species '  (first  edition,  p.  199)  I  contented 
myself  by  merely  alluding  to  this  belief.  When  I  came 
to  apply  this  view  to  man,  I  found  it  indispensable  to 
treat  the  whole  subject  in  full  detail."  Consequently 
the  second  part  of  the  present  work,  treating  of  sexual 
selection,  has  extended  to  an  inordinate  length,  com- 
pared with  the  first  part ;  but  this  could  not  be 
avoided. 

I  had  intended  adding  to  the  present  volumes  an 
essay  on  the  expression  of  the  various  emotions  by  man 
and  the  lower  animals.  My  attention  was  called  to  this 
subject  many  years  ago  by  Sir  Charles  Bell's  admirable 

*  Prof.  Hiickel  is  the  sole  author  who,  since  the  publication  of  the 
'  Origin,'  has  discussed,  in  his  various  works,  in  a  very  able  manner,  the 
subject  of  sexual  selection,  and  has  seen  its  full  importance. 


G  INTRODUCTIOX. 

work.  This  illustrious  anatomist  maintains  that  man 
is  endowed  with  certain  muscles  solely  for  the  sake 
of  expressing  his  emotions.  As  this  view  is  obviously 
opposed  to  the  belief  that  man  is  descended  from  some 
other  and  lower  form,  it  was  necessary  for  me  to  con- 
sider it.  I  likewise  wished  to  ascertain  how  far  the 
emotions  are  expressed  in  the  same  manner  by  the  dif- 
ferent races  of  man.  But,  owing  to  the  length  of  the 
present  work,  I  have  thought  it  better  to  reserve  my 
essay,  which  is  partially  completed,  for  separate  pub- 
lication. 


PART  I. 

THE  DESCENT  OR   ORIGIN  OF  MAN. 


THE   DESOEJSTT   OF  MAE". 


CHAPTER  I. 

THE    EVIDENCE    OF   THE  DESCENT    OF    MAN    FROM    SOME 
LOWER   FORM. 

Nature  of  the  Evidence  bearing  on  tlie  Origin  of  Man.— Homologous  struct- 
ures in  Man  and  the  Lower  Animals. — Miscellaneous  Points  of  Corre- 
spondence.— Development. — Kudimentary  Structures,  Muscles,  Sense- 
organs,  Hair,  Bones,  Eeproductive  Organs,  etc.— The  Bearing  of  these 
three  great  Classes  of  Facts  on  the  Origin  of  Man. 

He  who  wishes  to  decide  whether  man  is  the  modified 
descendant  of  some  preexisting  form,  would  probably  first 
inquire  whether  man  varies,  however  slightly,  in  bodily 
structure  and  in  mental  faculties ;  and  if  so,  whether  the 
variations  are  transmitted  to  his  offspring  in  accordance 
with  the  laws  which  prevail  with  the  lower  animals ;  such 
as  that  of  the  transmission  of  characters  to  the  same  age 
or  sex.  Again,  are  the  variations  the  result,  as  far  as  our 
ignorance  permits  us  to  judge,  of  the  same  general  causes, 
and  are  they  governed  by  the  same  general  laws,  as  in  the 
ease  of  other  organisms ;  for  instance,  by  correlation,  the 
inherited  eifects  of  use  and  disuse,  etc.  ?  Is  man  subject  to 
similar  malconformations,  the  result  of  arrested  develop- 
ment, of  reduplication  of  parts,  etc.,  and  does  he  display 
in  any  of  his  anomalies  reversion  to  some  former  and  an- 
cient type  of  structure?    It  might  also  naturally  be  in- 


10  THE   DESCENT   OF  MAN.  [Part  I. 

quired  whether  man,  like  so  many  other  animals,  has  given 
rise  to  varieties  and  sub-races,  differing  but  slightly  from 
each  other,  or  to  races  differing  so  much  that  they  must  be 
classed  as  doubtful  species  ?  How  are  such  races  distrib- 
uted over  the  world ;  and  how,  when  crossed,  do  they  react 
on  each  other,  both  in  the  first  and  succeeding  genera- 
tions ?   And  so  with  many  other  points. 

The  inquirer  would  next  come  to  the  important  point, 
whether  man  tends  to  increase  at  so  rapid  a  rate,  as  to 
lead  to  occasional  severe  struggles  for  existence,  and  con- 
sequently to  beneficial  variations,  whether  in  body  or 
mind,  being  preserved,  and  injurious  ones  eliminated.  Do 
the  races  or  species  of  men,  whichever  term  may  be  ap- 
plied, encroach  on  and  replace  each  other,  so  that  some 
finally  become  extinct  ?  We  shall  see  that  all  these  ques- 
tions, as  indeed  is  obvious  in  respect  to  most  of  them, 
must  be  answered  in  the  affirmative,  in  the  same  manner 
as  with  the  lower  animals.  But  the  several  considerations 
just  referred  to  may  be  conveniently  deferred  for  a  time ; 
and  we  will  first  see  how  far  the  bodily  structure  of  man 
shows  traces,  more  or  less  plain,  of  his  descent  from  some 
lower  form.  In  the  two  succeeding  chapters  the  mental 
powers  of  man,  in  comparison  with  those  of  the  lower 
animals,  Avill  be  considered. 

The  Bodily  Structure  of  3fan. — It  is  notorious  that 
man  is  constructed -on  the  same  general  type  or  model 
■with  other  mammals.  All  the  bones  in  his  skeleton  can 
be  compared  with  corresponding  bones  in  a  monkey,  bat, 
or  seal.  So  it  is  with  his  muscles,  nerves,  blood-vessels, 
and  internal  viscera.  The  brain,  the  most  important  of 
all  the  organs,  follows  the  same  law,  as  shown  by  Huxley 
and  other  anatomists.  Bischoft','  who  is  a  hostile  witness, 
admits  that  every  chief  fissure  and  fold  in  the  brain  of 

'  '  Grosshimwindungen  des  Menchen,'  I8G8,  s.  96. 


Chap.  I.]  HOMOLOGICAL   STRUCTURE.  n 

man  has  its  analogy  in  that  of  the  orang ;  but  he  adds 
that  at  no  period  of  development  do  their  brains  perfectly 
agree ;  nor  conld  this  be  expected,  for  otherwise  their 
mental  powers  would  have  been  the  same.  Vulpian'  re- 
marks :  "  Les  difterences  reelles  qui  existent  entre  I'ence- 
phale  de  I'homme  et  celui  des  singes  superieiirs,  sont  bien 
minimes.  II  ne  faut  pas  se  faire  d'illusions  k  cet  cgard. 
L'homme  est  bien  plus  pres  des  singes  anthropomorphes 
par  les  caract^res  anatomiques  de  son  cerveau  que  ceux-ci 
ne  le  sont  non-seulement  des  autres  mammiferes,  mais 
memes  de  certains  quadrumanes,  des  guenons  et  des  ma- 
caques." But  it  would  be  superfluous  here  to  give  fur- 
ther details  on  the  correspondence  between  man  and  the 
higher  mammals  in  the  structure  of  the  brain  and  all 
other  parts  of  the  body. 

It  may,  however,  be  worth  while  to  specify  a  few 
points,  not  directly  or  obviously  connected  with  struct- 
ure, by  which  this  correspondence  or  relationship  is  well 
shown. 

Man  is  liable  to  receive  from  the  lower  animals,  and  to 
communicate  to  them,  certain  diseases,  as  hydrophobi:!, 
variola,  the  glanders,  etc. ;  and  this  fact  proves  the  close 
similarity  of  their  tissues*  and  blood,  both  in  minute  struct- 
ure and  composition,  far  more  plainly  than  does  their  com- 
parison under  the  best  microscope,  or  by  the  aid  of  the 
best  chemical  analysis.  Monkeys  are  liable  to  many  of 
the  same  non-contagious  diseases  as  we  are  ;  thus  Reng- 
ger,'  who  carefully  observed  for  a  long  time  the  Cebus 
Azarcie  in  its  native  land,  found  it  liable  to  catarrh,  with 
the  usual  symptoms,  and  which  when  often  recurrent  led 
to  consumption.  These  monkeys  sufiered  also  from  apo- 
plexy, inflammation  of  the  bowels,  and  cataract  in  the  eye. 

«  'Le?.  sur  la  Phys.'  1866,  p.  890,  as  quoted  by  M.  Dally,  '  L'Ordre 
des  Primates  et  le  Transformisme,'  1868,  p.  29. 

*  '  Naturgeschichte  der  Saugethiere  von  Paraguay,'  1830,  s.  50. 


1 2  THE   DESCENT   OF   MAN.  [Part  I. 

The  younger  ones  when  shedding  their  milk-teeth  often 
died  from  fever.  Medicines  produced  the  same  effect  on 
them  as  on  us.  Many  kinds  of  monkeys  have  a  strong 
taste  for  tea,  coffee,  and  spirituous  liquors :  they  will  also, 
as  I  have  myself  seen,  smoke  tobacco  with  pleasure. 
Brehm  asserts  that  the  natives  of  nortlieastern  Africa 
catch  the  wild  baboons  by  exposing  vessels  with  strong 
beer,  by  which  tliey  are  made  drunk.  He  lias  seen  some 
of  these  animals,  which  he  kept  in  confinement,  in  this 
state ;  and  he  gives  a  laughable  account  of  their  behavior 
and  strange  grimaces.  On  the  following  morning  they 
were  very  cross  and  dismal ;  they  held  their  aching  heads 
with  both  hands  and  wore  a  most  pitiable  expression ; 
when  beer  or  wine  was  offered  them,  they  turned  away 
with  disgust,  but  relished  the  juice  of  lemons.^  An  Amer- 
ican monkey,  an  Ateles,  after  getting  drunk  on  brandy, 
would  never  touch  it  again,  and  thus  was  wiser  than  many 
men.  These  trifling  facts  prove  how  similar  the  nerves 
of  taste  must  be  in  monkeys  and  man,  and  how  similarly 
their  whole  nervous  system  is  affected. 

Man  is  infested  with  internal  parasites,  sometimes 
causing  fatal  effects,  and  is  plagued  by  external  parasites, 
all  of  which  belong  to  the  same  genera  or  families  Avith 
those  infesting  other  mammals.  Man  is  subject  like  other 
mammals,  birds,  and  even  insects,  to  that  mysterious  law, 
which  causes  certain  normal  processes,  such  as  gestation, 
as  well  as  the  maturation  and  duration  of  various  diseases, 
to  follow  lunar  periods.^  His  wounds  are  repaired  by  the 
same  process  of  healing  ;  and  the  stumps  left  after  the 

*  Brehm,  '  Thierleben,'  B.  i.  1864,  s.  '75,  86.  On  the  Ateles,  s.  105. 
For  other  analogous  statcmeuts,  see  s.  25,  107. 

*  With  respect  to  insects  see  Dr.  Laycock  '  On  a  General  Law  of 
Vital  Periodicity,'  British  Association,  1842.  Dr.  MaccuUoch,  'Silliman's 
North  American  Journal  of  Science,'  vol.  xvii.  p.  305,  has  seen  a  dog  suf- 
fering from  tertian  ague. 


Chap.  I.]  HOMOLOGICAL   STRUCTURE.  13 

amputation  of  his  limbs  occasionally  possess,  especially 
during  an  early  embryonic  period,  some  power  of  regen- 
eration, as  in  the  lowest  animals.* 

The  whole  process  of  that  most  important  function, 
the  reproduction  of  the  species,  is  strikingly  the  same  in 
all  mammals,  from  the  first  act  of  courtship  by  the  male ' 
to  the  birth  and  nurturing  of  the  young.  Monkeys  are 
born  in  almost  as  helpless  a  condition  as  our  own  infants ; 
and  in  certain  genera  the  young  differ  fully  as  much  in 
appearance  from  the  adults,  as  do  our  children  from  their 
full-grown  parents.*  It  has  been  urged  by  some  writers 
as  an  important  distinction,  that  with  man  the  young 
arrive  at  maturity  at  a  much  later  age  than  with  any  other 
animal :  but  if  we  look  to  the  races  of  mankind  which 
inhabit  tropical  countries  the  diiference  is  not  great,  for 
the  orang  is  believed  not  to  be  adult  till  the  age  of  from 
ten  to  fifteen  years.'  Man  differs  from  woman  in  size, 
bodily  strength,  hairyness,  etc.,  as  well  as  in  mind,  in  the 
same  manner  as  do  the  two  sexes  of  many  mammals.  It 
is,  in  short,  scarcely  possible  to  exaggerate  the  close  cor- 

®  I  have  given  the  evidence  on  this  head  in  my  '  Variation  of  Animals 
and  Plants  under  Domestication,'  vol.  ii.  p.  15. 

'  "Mares  e  diversis  generibus  Quadrumanorum  sine  dubio  dignoscunt 
feminas  huraanas  a  maribus.  Primum,  credo,  odoratu,  postea  aspectu. 
Mr.  Youatt,  qui  din  in  Hortis  Zoologicis  (Bestiariis)  medicus  animalium 
erat,  vir  in  rebus  observandis  cautus  et  sagax,  hoc  mihi  certissime  pro- 
bavit,  et  curatores  ejusdem  loci  et  alii  e  ministris  confirmavenmt.  Sir 
Andrew  Smith  et  Brehm  notabant  idem  in  Cynocephalo.  Illustrissimua 
Cuvier  etiam  narrat  multa  de  hac  re  qua  ut  opinor  nihil  turpius  potest 
indicari  inter  omnia  hominibus  et  Quadrumanis  communia.  Narrat  enim 
Cynocephalum  quendam  in  furorem  incidere  aspectu  feminarum  aliquarum, 
sed  nequaquam  accendi  tanto  furore  ab  omnibus.  Semper  eligebat  ju- 
niores,  et  dignoscebat  in  turba,  et  advocabat  voce  gestuque." 

^  This  remark  is  made  with  respect  to  Cynocephalus  and  the  anthropo- 
morphous apes  by  GeofiFroy  Saint-Hilaire  and  F.  Cuvier,  '  Hist.  Nat.  des 
Mammif^res,'  tom.  i.  1824. 

'  Huxley,  'Man's  Place  in  Nature,'  1863,  p.  34. 


14  THE   DESCENT   OF  MAN.  [Part  I. 

respondence  in  general  structure,  in  the  minute  structure 
of  the  tissues,  in  chemical  composition,  and  in  constitution, 
between  man  and  the  higher  animals,  especially  the  an- 
thropomorphous apes. 

Embryonic  Development. — Man  is  developed  from  an 
ovule,  about  the  125th  of  an  inch  in  diameter,  which 
differs  in  no  respect  from  the  ovules  of  other  animals. 
The  embryo  itself  at  a  very  early  period  can  hardly  be 
distinguished  from  that  of  other  members  of  the  verte- 
brate kingdom.  At  this  period  the  arteries  run  in  arch- 
like branches,  as  if  to  carry  the  blood  to  branchise  which 
are  not  present  in  the  higher  vertebrata,  though  the  slits 
on  the  sides  of  the  neck  still  remain  (y,  (7,  fig.  1),  marking 
their  former  position.  At  a  somewhat  later  period,  when 
the  extremities  are  developed,  "  the  feet  of  lizax'ds  and 
mammals,"  as  the  illustrious  Von  Baer  remarks,  "the 
/  wings  and  feet  of  birds,  no  less  than  the  hands  and  feet 
of  man,  all  arise  from  the  same  fundamental  form."  It 
is,  says  Prof.  Huxley,"  "  quite  in  the  latter  stages  of  de- 
velopment that  the  young  human  being  presents  marked 
differences  from  the  young  ape,  while  the  latter  departs  as 
much  from  the  dog  in  its  developments,  as  the  man  does. 
Startling  as  this  last  assertion  may  appear  to  be,  it  is  de- 
monstrably true." 

As  some  of  my  readers  may  never  have  seen  a  draw- 
ing of  an  embryo,  I  have  given  one  of  man  and  another 
of  a  dog,  at  about  the  same  early  stage  of  development, 
carefully  copied  from  two  works  of  undoubted  accuracy." 

"  '  Man's  Place  in  Nature,'  1863,  p.  67. 

"The  human  embryo  (upper  fig.)  is  from  Ecker,  'Icones  Phys.,' 
1851-1850,  tab.  xxx.  fig.  2.  This  embryo  was  ten  lines  in  length,  so  that 
the  drawing  is  much  magnified.  The  embryo  of  the  dog  is  from  Bi- 
schoff,  'Entwicklungsgcschichte  dcs  Hunde-Eies,'  1845,  tab.  xi.  fig.  42  b. 
This  drawing  is  five  times  magnified,  the  embryo  being  25  days  old.    The 


Chap.  I.] 


EMBRYONIC   DEVELOPMENT. 


15 


Fig.  1.— Upper  figure  human  embryo,  from  Ecker.    Lower  figure  that  of  a  dog, 
from  Bischoff. 


a.  Fore-brain,  cerebral  hemispheres, 
etc. 

b.  Mid-brain,  corpora  quadrisemina. 

c.  Hind-brain,  cerebellum,  medulla 
oblongata. 

d.  Eye. 

e.  Ear. 


f.  First  visceral  arch. 
p.  Second  visceral  arch. 
H.  Vertebral  columns  and  muscles  in 
process  of  development. 

ll:iSSr[  extremities. 

L.  Tail  or  os  coccyx. 


16  THE   DESCENT   OF   MAN.  [Part  I. 

After  the  foregoing  statements  made  by  such  high 
authorities,  it  would  be  superfluous  on  my  part  to  give  a 
number  of  borrowed  details,  showing  that  the  embryo  of 
man  closely  resembles  that  of  other  mammals.  It  may, 
however,  be  added  that  the  human  embryo  likewise  resem- 
bles in  various  points  of  structure  certain  low  forms  when 
adult.  For  instance,  the  heart  at  first  exists  as  a  simple 
pulsating  vessel ;  the  excreta  arc  voided  through  a  cloacal 
passage  ;  and  the  os  coccyx  projects  like  a  true  tail,  "  ex- 
tending considerably  beyond  the  rudimentary  legs."  "  In 
the  embryos  of  all  air-breathing  vertebrates,  certain  glands 
called  the  corpora  Wolffiana,  correspond  Avith  and  act  like 
the  kidneys  of  mature  fishes.''  Even  at  a  later  embryo- 
nic period,  some  striking  resemblances  between  man  and 
the  lower  animals  may  be  observed,  Bischoff  says  that 
the  convolutions  of  the  brain  in  a  human  foetus  at  the  end 
of  the  seventh  month  reach  about  the  same  stage  of  de- 
velopment as  in  a  baboon  when  adult."  The  great  toe, 
as  Prof.  Owen  remarks,"  "  which  forms  the  fulcrum  when 
standing  or  walking,  is  perhaps  the  most  characteristic 
peculiarity  in  the  human  structure ; "  but  in  an  embryo, 
about  an  inch  in  length,  Prof  Wyman  '"  found  that  the 
great  toe  was  shorter  than  the  others,  and,  instead  of  be- 
ing parallel  to  them,  projected  at  an  angla  from  the  side 
of  the  foot,  thus  corresponding  vdth  the  permanent  condi- 

internal  viscera  have  been  oraitted,  and  the  uterine  appendages  in  both 
drawin<^3  removed.  I  was  directed  to  these  figures  by  Prof.  Huxley, 
from  whose  work,  '  Man's  Place  in  Nature,'  the  idea  of  giving  them  was 
taken.  Hiickel  has  also  given  analogous  drawings  in  his  '  Schopfungs- 
geschichte.' 

"  Prof.  Wyman  in  '  Proc.  of  American  Acad,  of  Sciences,'  vol.  iv. 
1860,  p.  17. 

'3  Owen,  'Anatomy  of  Vetebrates,'  vol.  i.  p.  533 

"  'Die  Grosshirnwindungen  des  Menschen,'  1868,  s.  95 

'5  '  Anatomy  of  Vertebrates,*  vol.  ii.  p.  553. 

'«  'Proc.  See.  Nat.  Hist.'    Boston,  1863,  vol.  ix.  p.  185. 


Chap  I.]  RUDIMENTS.  17 

tion  of  this  part  in  the  qiTadrumana,"  I  will  conclude  with 
a  quotation  from  Huxley,"  who,  after  asking,  does  man 
originate  in  a  different  way  from  a  dog,  bird,  frog,  or  fish  ? 
says,  "  the  reply  is  not  doubtful  for  a  moment ;  without 
question,  the  mode  of  origin  and  the  early  stages  of  the 
development  of  man  are  identical  with  those  of  the  ani- 
mals immediately  below  him  in  the  scale :  without  a  doubt 
in  these  respects,  he  is  far  nearer  to  apes,  than  the  apes 
are  to  the  dog." 

Mudiments. — This  subject,  though  not  intrinsically 
more  important  than  the  last  two,  wi|l  for  several  reasons 
be  here  treated  with  more  fulness."  Not  one  of  the 
higher  animals  can  be  named  which  does  not  bear  some 
part  in  a  rudimentary  condition ;  and  man  forms  no  ex- 
ception to  the  rule.  Rudimentary  organs  must  be  dis- 
tinguished from  those  that  are  nascent ;  though  in  some 
cases  the  distinction  is  not  easy.  The  former  ai*e  either 
absolutely  useless,  such  as  the  mammae  of  male  quad- 
rupeds, or  the  incisor  teeth  of  ruminants  which  never  cut 
through  the  gums ;  or  they  are  of  such  slight  service  to 
their  present  possessors,  that  we  cannot  suppose  that  they 
were  developed  under  the  conditions  which  now  exist. 
Organs  in  this  latter  state  are  not  strictly  rudimentary, 
but  they  are  tending  in  this  direction.  Nascent  organs, 
on  the  other  hand,  though  not  fully  developed,  are  of  high 
service  to  their  possessors,  and  are  capable  of  further  de- 
velopment. Rudimentary  organs  are  eminently  variable  ; 
and  this  is  partly  intelligible,  as  they  are  useless  or  nearly 

'■'  '  Man's  Place  in  Nature,'  p.  65. 

^^  I  had  written  a  rough  copy  of  this  chapter  before  reading  a  valu- 
able paper,  "  Caratteri  rudimentali  in  ordine  all '  origine  del  uomo  "  ('Au- 
nuario  della  Soc.  d.  Nat.,'  Modena,  186Y,  p.  81),  by  G.  Canestrini,  to 
which  paper  I  am  considerably  indebted.  Hiickel  has  given  admirable 
discussions  on  this  whole  subject,  under  the  title  of  Dysteleology,  in  hii. 
'  Generclle  Moi'phologie '  and  '  Schopfungsgeschichte.' 
2 


18  THE  DESCENT   OF   MAN.  [Part  I. 

useless,  and  consequently  are  no  longer  subjected  to  nat- 
ural selection.  They  often  become  wholly  suppressed. 
When  this  occurs,  they  are  nevertheless  liable  to  occa- 
sional reappearance  through  reversion ;  and  this  is  a  cir- 
cumstance weK  worthy  of  attention. 

Disuse  at  that  period  of  life,  when  an  organ  is  chiefly 
used,  and  this  is  generally  during  maturity,  together  with 
inheritance  at  a  corresponding  period  of  life,  seem  to  have 
been  the  chief  agents  in  causing  organs  to  become  rudi- 
mentary. The  term  "  disuse  "  does  not  relate  merely  to 
the  lessened  action  of  muscles,  but  includes  a  diminished 
flow  of  blood  to  a  part  or  organ,  from  being  subjected  to 
fewer  alternations  of  pressure,  or  from  becoming  in  any 
way  less  habitually  active.  Rudiments,  however,  may 
occur  in  one  sex  of  parts  normally  present  in  the  other 
sex ;  and  such  rudiments,  as  we  shall  hereafter  sec,  have 
often  originated  in  a  distinct  manner.  In  some  cases  or- 
gans have  been  reduced  by  means  of  natural  selection, 
from  having  become  injurious  to  the  species  under  changed 
habits  of  life.  The  process  of  reduction  is  probably  often 
aided  through  the  two  principles  of  compensation  and 
economy  of  growth;  but  the  later  stages  of  reduction, 
after  disuse  has  done  all  that  can  fairly  be  attributed  to  it, 
and  when  the  saving  to  be  effected  by  the  economy  of 
growth  would  be  very  small,"  are  difficult  to  understand. 
The  final  and  complete  suppression  of  a  part,  already  use- 
less and  much  reduced  in  size,  in  which  case  neither  com- 
pensation nor  economy  can  come  into  play,  is  perhaps  in- 
telligible by  the  aid  of  the  hypothesis  of  i)angencsis,  and 
apparently  in  no  other  way.  But  as  the  whole  subject  of 
rudimentary  organs  has  been  fully  discussed  and  illustrated 
in  my  former  works,'"*  I  need  here  say  no  more  on  this  head. 

'*  Some  good  criticisms  on  this  subject  have  been  given  by  Messrs. 
Murie  and  Mivart,  in  'Transact.  Zoolog.  Soc'  1869,  vol.  vii.  p.  92. 

so  I  Variation  of  Animals  and  Plants  under  Domestication,'  vol.  ii.  pp. 
817  and  397.     See  also  '  Origin  of  Species,'  5th  edit.  p.  535. 


Chap.  I.]  RUDIMENTS.  19 

Rudiments  of  various  muscles  have  been  observed  in 
many  parts  of  the  human  body ;  ^'  and  not  a  few  muscles, 
which  are  regularly  present  in  some  of  the  lower  animals 
can  occasionally  be  detected  in  man  in  a  greatly  reduced 
condition.  Every  one  must  have  noticed  the  power  which 
many  animals,  especially  horses,  possess  of  moving  or 
twitching  their  skin ;  and  this  is  eftected  by  the  pannicu- 
lus  carnosus.  Remnants  of  this  muscle  in  an  efficient 
state  are  found  in  various  parts  of  our  bodies ;  for  in- 
stance, on  the  forehead,  by  which  the  eyebrows  are  raised. 
The  platysma  myoides,  which  is  well  developed  on  the 
neck,  belongs  to  this  system,  but  cannot  be  voluntarily 
brought  into  action.  Prof.  Turner,  of  Edinburgh,  has 
occasionally  detected,  as  he  informs  me,  muscular  fasciculi 
in  five  different  situations,  namely,  in  the  axillge,  near  the 
scapulae,  etc.,  all  of  which  must  be  referred  to  the  system 
of  the  panniculus.  He  has  also  shown  °^  that  the  musculus 
sternalis  or  sternalis  brutorum,  which  is  not  an  extension 
of  the  rectus  ahdominalis,  but  is  closely  allied  to  the 
panniculus,  occurred  in  the  proportion  of  about  three  per 
cent,  in  upward  of  six  hundred  bodies :  he  adds,  that  this 
muscle  affords  "an  excellent  illustration  of  the  statement 
that  occasional  and  rudimentary  structures  are  especially 
liable  to  variation  in  arrangement." 

Some  few  persons  have  the  power  of  contracting  the 
superficial  muscles  on  their  scalps  ;  and  these  muscles  are 
in  a  variable  and  partially  rudimentary  condition.  M.  A. 
de  Candolle  has  communicated  to  me  a  curious  instance 
of  the  long-continued  persistence  or  inheritance  of  this 

*'  For  instance,  M.  Richard  ('Annales  des  Sciences  Nat.'  3d  series, 
Zoolog.  1852,  torn,  xviii.  p.  13)  describes  and  figures  rudiments  of  what 
he  calls  the  "  muscle  pedieux  de  la  main,"  which  he  says  is  sometimes 
"infiniment  petit."  Another  muscle,  called  "le  tibial  posterieur,"  is  gen- 
erally quite  absent  in  the  hand,  but  appears  from  time  to  time  in  a  more 
or  less  rudimentary  condition. 

"5  Prof.  W.  Turner,  'Proc.  Royal  Soc.  Edinburgh,'  1866-67,  p.  65. 


20  THE   DESCENT   OF   MAN.  [Part  I. 

power,  as  well  as  of  its  unusual  development.  He  knows 
a  family  in  which  one  member,  the  present  head  of  a 
family,  could,  when  a  youth,  pitch  several  heavy  books 
from  his  head  by  tlie  movement  of  the  scalp  alone ;  and 
he  won  wagers  by  performing  this  feat.  His  father,  uncle, 
grandfather,  and  all  his  three  children,  possess  the  same 
power  to  the  same  unusual  degree.  This  family  became 
divided  eight  generations  ago  into  two  branches;  so 
that  the  head  of  the  above-mentioned  branch  is  cousin  in 
the  seventh  degree  to  the  head  of  the  other  branch.  This 
distant  cousin  resides  in  another  part  of  France,  and,  on 
being  asked  whether  he  possessed  the  same  faculty,  im- 
mediately exhibited  his  power.  This  case  offers  a  good  il- 
lustration how  persistently  an  absolutely  useless  faculty 
may  be  transmitted. 

The  extrinsic  muscles  w^hich  serve  to  move  the  whole 
external  ear,  and  the  intrinsic  muscles  which  move  the 
different  parts,  all  of  Avhich  belong  to  the  system  of  the 
panniculus,  are  in  a  rudimentary  condition  in  man;  they 
are  also  variable  in  development,  or  at  least  in  function. 
I  have  seen  one  man  who  could  draw  his  ears  forward, 
and  another  who  could  draw  them  backward ; "  and,  from 
what  one  of  these  persons  told  me,  it  is  probable  that  most 
of  us,  by  often  touching  our  ears  and  thus  directing  our 
attention  toward  them,  could  by  repeated  trials  recover 
some  power  of  movement.  The  faculty  of  erecting  the 
ears  and  of  directing  them  to  different  points  of  the  com- 
pass, is  no  doubt  of  the  highest  service  to  many  animals, 
as  they  thus  perceive  the  point  of  danger ;  but  I  have  never 
heai'd  of  a  man  who  possessed  the  least  power  of  erecting 
his  ears — the  one  movement  which  might  be  of  use  to  him. 
The  whole  external  shell  of  the  ear  may  be  considered  a 
rudiment,  together  with  the  various  folds  and  prominences 

'*  Canestrini  quotes  llyrt.  ('  Annuurio  della  Soc.  dei  Naturalist!,' 
Modena,  18GY,  p.  97)  to  the  same  etlect. 


Chap.  I.]  RUDIMENTS.  21 

(helix  and  anti-helix,  tragus  and  anti-tragus,  etc.)  which 
in  the  lower  animals  strengthen  and  support  the  ear  when 
erect,  without  adding  much  to  its  weight.  Some  authors, 
however,  suj^j^ose  that  the  cartilage  of  the  shell  serves  to 
transmit  vibrations  to  the  acoustic  nerve ;  but  Mr.  Toyn- 
bee,''*  after  collecting  all  the  known  evidence  on  this  head, 
concludes  that  the  external  shell  is  of  no  distinct  use. 
The  ears  of  the  chimpanzee  and  orang  are  curiously  like 
those  of  man,  and  I  am  assured  by  the  keepers  in  the  Zoo- 
logical Gardens  that  these  animals  never  move  or  erect 
them ;  so  that  they  are  in  an  equally  rudimentary  condi- 
tion, as  far  as  function  is  concerned,  as  in  man.  Why 
these  animals,  as  well  as  the  progenitors  of  man,  should 
have  lost  the  power  of  erecting  their  ears  we  cannot  say. 
It  may  be,  though  I  am  not  quite  satisfied  with  this  view, 
that  owing  to  their  arboreal  habits  and  great  strength  they 
were  but  little  exposed  to  danger,  and  so  during  a  length- 
ened period  moved  their  ears  but  little,  and  thus  gradually 
lost  the  power  of  moving  them.  This  would  be  a  parallel 
case  with  that  of  those  large  and  heavy  birds,  which  from 
inhabiting  oceanic  islands  have  not  been  exposed  to  the 
attacks  of  beasts  of  prey,  and  have  consequently  lost  the 
power  of  using  their  wings  for  flight. 

The  celebrated  sculptor,  Mr.  Woolnei*,  informs  me  of 
one  little  peculiarity  in  the  external  ear,  which  he  has 
often  observed  both  in  men  and  women,  and  of  which  he 
perceived  the  full  signification.  His  attention  was  first 
called  to  the  subject  while  at  work  on  his  figure  of  Puck, 
to  which  he  had  given  pointed  ears.  He  was  thus  led  to 
examine  the  ears  of  various  monkeys,  and  subsequently 
more  carefully  those  of  man.  The  peculiarity  consists  in 
a  little  blunt  point,  projecting  from  the  inwardly-folded 
margin,  or  helix.  Mr.  Woolner  made  an  exact  model  of 
one  such  case,  and  has  sent  me  the  accompanying  draw- 

^*  '  The  Diseases  of  the  Ear,'  by  J.  Toynbee,  F.  R.  S.,  1860,  p.  12. 


22 


TnE   DESCENT   OF   MAN. 


[Part  I. 


Fig.  2.— Human  Ear,  modelled 

and  drawn  by  Mr.  Woolner. 

a.  The  projecting  point. 


ing.  (Fig.  2.)  Those  points  not  only  project  inward,  but 
often  a  little  outward,  so  that  they  are  visible  when  the 
head  is  viewed  from  directly  in  front  or  behind.  They  are 
variable  in  size  and  somewhat  in  po- 
sition, standing  either  a  little  high- 
er or  lower ;  and  they  sometimes 
occur  in  one  ear  and  not  on  the 
other.  Now  the  meaning  of  these 
projections  is  not,  I  think,  doubt- 
ful ;  but  it  may  be  thought  that 
they  offer  too  trifling  a  character 
to  be  worth  notice.  This  thought, 
however,  is  as  false  as  it  is  natural. 
Every  character,  however  slight, 
must  be  the  result  of  some  definite 
cause ;  and  if  it  occurs  in  many 
individuals  deserves  consideration. 
The  helix  obviously  consists  of  the  extreme  margin  of  the 
ear  folded  inward ;  and  this  folding  appears  to  be  in  some 
manner  connected  with  the  whole  external  ear,  being  per- 
manently pressed  backward.  In  many  monkeys,  which 
do  not  stand  high  in  the  order,  as  baboons  and  some 
species  of  macacus,"  the  upper  portion  of  the  ear  is 
slightly  pointed,  and  the  margin  is  not  at  all  folded  in- 
ward ;  but  if  the  margin  were  to  be  thus  folded,  a  slight 
point  would  necessarily  project  inward  and  probably  a 
little  outward.  This  could  actually  be  observed  in  a 
specimen  of  the  Ateles  heelzebuth  in  the  Zoological  Gar- 
dens ;  and  we  may  safely  conclude  that  it  is  a  similar 
structure — a  vestige  of  formerly-pointed  ears — which  oc- 
casionally reappears  in  man. 

The  nictitating  membrane,  or  third  eyelid,  with  its 

"^  See  also  some  remarks,  and  the  drawings  of  the  ears  of  the  Lemu- 
roidea,  in  Messrs.  Murie  and  Mivart's  excellent  paper  in  '  Transact.  Zoo- 
log.  Soc.'  vol.  vii.  1869,  pp.  G  and  90. 


Chap.  I.]  RUDIMENTS.  23 

accessory  muscles  and  other  structures,  is  especially  well 
developed  in  birds,  and  is  of  much  functional  importance 
to  them,  as  it  can  be  rapidly  drawn  across  the  whole  eye- 
ball. It  is  found  in  some  reptiles  and  amphibians,  and  in 
certain  fishes,  as  in  sharks.  It  is  fairly  well  developed  in 
the  two  lower  divisions  of  the  mammalian  series,  namely, 
in  the  monotremata  and  marsupials,  and  in  some  few  of 
the  higher  mammals,  as  in  the  walrus.  But  in  man,  the 
qiiadrumana,  and  most  other  mammals,  it  exists,  as  is  ad- 
mitted by  all  anatomists,  as  a  mere  rudiment,  called  the 
semilunar  fold.''® 

The  sense  of  smell  is  of  the  highest  importance  to  the 
greater  number  of  mammals — to  some,  as  the  ruminants, 
in  warning  them  of  danger ;  to  others,  as  the  carnivora,  in 
finding  their  prey ;  to  others,  as  the  wild-boar,  for  both 
purposes  combined.  But  the  sense  of  smell  is  of  ex- 
tremely slight  service,  if  any,  even  to  savages,  in  whom  it 
is  generally  more  highly  developed  than  in  the  civilized 
races.  It  does  not  warn  them  of  danger,  nor  guide  them 
to  their  food;  nor  does  it  prevent  the  Esquimaux  from 
sleeping  in  the  most  fetid  atmosphere,  nor  many  savages 
from  eating  half-putrid  meat.  Those  who  believe  in  the 
principle  of  gradual  evolution,  will  not  readily  admit  that 
this  sense  in  its  present  state  was  originally  acquired  by 
man,  as  he  now  exists.  No  doubt  he  inherits  the  power 
in  an  enfeebled  and  so  far  rudimentary  condition,  from 
some  early  progenitor,  to  whom  it  was  highly  serviceable 
and  by  whom  it  was  continually  used.  We  can  thus 
perhaps  understand  how  it  is,  as  Dr.  Maudsley  has  truly 

''  Miiller's  'Elements  of  Physiology,'  Eng.  translat.,  1842,  vol.  ii.  p. 
111?.  Owen,  'Anatomy  of  Vertebrates,'  vol.  iii.  p.  260;  ibid,  on  the 
Walrus,  '  Proc.  Zoolog.  Soc.'  November  8,  1854.  See  also  R.  Knox, 
'  Great  Artists  and  Anatomists,'  p.  106.  This  rudiment  apparently  is 
somewhat  larger  in  Negroes  and  Australians  than  in  Europeans,  see  Carl 
Vogt,  '  Lectures  on  Man,'  Eng.  translat.  p.  129. 


24  THE   DESCENT   OF   MAN.  [Part  I. 

remarked,'"  that  the  sense  of  smell  in  man  "  is  singularly 
effective  in  recalling  vividly  the  ideas  and  images  of  for- 
gotten scenes  and  places ; "  for  we  see  in  those  animals, 
which  have  this  sense  highly  developed,  such  as  dogs  and 
horses,  that  old  recollections  of  persons  and  places  are 
strongly  associated  with  their  odor. 

Man  differs  conspicuously  from  all  the  other  Primates 
in  being  almost  naked.  But  a  few  short,  strao-fjlinsi:  hairs 
are  found  over  the  greater  part  of  the  body  in  the  male 
sex,  and  fine  down  on  that  of  the  female  sex.  In  individ- 
uals belonging  to 'the  same  race  these  hairs  are  highly 
variable,  not  only  in  abundance,  but  likewise  in  position  : 
thus  the  shoulders  in  some  Europeans  are  quite  naked, 
while  in  others  they  bear  thick  tufts  of  hair."  There  can 
be  little  doubt  that  the  hairs  thus  scattered  over  the  body 
are  the  rudiments  of  the  uniform  hairy  coat  of  the  lower 
animals.  This  view  is  rendered  all  the  more  probable,  as 
it  is  known  that  fine,  short,  and  pale-colored  hairs  on  the 
limbs  and  other  parts  of  the  body  occasionally  become 
developed  into  "  thickset,  long,  and  rather  coarse  dark 
hairs,"  when  abnormally  nourished  near  old-standing  in- 
flamed surfaces. "° 

I  am  inforiiied  by  Mr.  Paget  that  persons  belonging 
to  the  same  family  often  have  a  few  hairs  in  their  eye- 
brows much  longer  than  the  others ;  so  that  this  slight 
peculiarity  seems  to  be  inherited.  These  hairs  apparently 
represent  the  vibrissce,  which  are  used  as  organs  of  touch 
by  many  of  the  lower  animals.  In  a  young  chimpanzee  I 
observed  that  a  few  upright,  rather  long,  hairs  projected 


"  'The  Physiology  and  Pathology  of  Mind,'  2d  edit.  1868,  p.  134. 

'*  Eschrieht,  Ucber  die  Riehtungder  Haare  am  menschliohi-n  Kcirp  er, 
'Miiller's  Archiv  fiir  Anat.  iind  Phys.'  1837,  s.  47.  I  shall  often  have  to 
refer  to  this  very  curious  paper. 

*'  Paget,  'Lectures  on  Surgical  Pathology,'  1853,  vol.  i.  p.  71. 


Chap.  I.J  RUDIMENTS.  25 

above  the  eyes,  where  the  true  eyebrows,  if  present,  would 
have  stood. 

The  line  wool-like  hair,  or  so-called  lanugo,  with  which 
the  human  foetus  during  the  sixth  month  is  thickly  cov- 
ered, offers  a  more  curious  case.  It  is  first  developed 
during  the  fifth  month,  on  the  eyebrows  and  face,  and  es- 
pecially round  the  mouth,  where  it  is  much  longer  than 
that  on  the  head.  A  mustache  of  this  kind  was  observed 
by  Eschricht  ^°  on  a  female  foetus  ;  but  this  is  not  so  sur- 
prising a  circumstance  as  it  may  at  first  appear,  for  the 
two  sexes  generally  resemble  eacli  other  in  all  external 
characters  during  an  early  period  of  growth.  The  direc- 
tion and  arrangement  of  the  hairs  on  all  parts  of  the  foetal 
body  are  the  same  as  in  the  adult,  but  are  subject  to  much 
variability.  The  whole  surface,  including  even  the  fore- 
head and  ears,  is  thus  thickly  clothed ;  but  it  is  a  signifi- 
cant fact  that  the  palms  of  the  hands  and  the  soles  of  the 
feet  are  quite  naked,  like  the  inferior  surfaces  of  all  four 
extremities  in  most  of  the  lower  animals.  As  this  can 
hardly  be  an  accidental  coincidence,  we  must  consider  the 
woolly  covering  of  the  foetus  to  be  the  rudimental  repre- 
sentative of  the  first  permanent  coat  of  hair  in  those 
mammals  which  are  born  hairy.  This  representation  is 
much  more  complete,  in  accordance  with  the  usual  law  of 
embiyological  development,  than  that  afforded  by  the 
straggling  hairs  on  the  body  of  the  adult. 

It  appears  as  if  the  posterior  molar  or  wisdom-teeth 
were  tending  to  become  rudimentary  in  the  more  civilized 
races  of  man.  These  teeth  are  rather  smaller  than  the 
other  molars,  as  is  likewise  the  case  with  the  correspond- 
ing teeth  in  the  chimpanzee  and  orang ;  and  they  have 
only  two  separate  fangs.  They  do  not  cut  through  the 
gums  till  about  the  seventeenth  year,  and  I  am  assured 
by  dentists  that  they  are  much  more  liable  to  decay,  and 
20  Eschricht,  ibid.  s.  40,  47. 


2G  THE   DESCENT   OF   MAN.  [Part  I. 

are  earlier  lost,  than  tlie  other  teeth.  It  is  also  remark- 
able that  they  are  much  more  liable  to  vary  both  in  struct- 
ure and  in  the  period  of  their  development  than  the  other 
teeth.^'  In  the  Melanian  races,  on  the  other  hand,  the 
wisdom-teeth  are  usually  furnished  with  three  separate 
fangs,  and  are  generally  sound :  they  also  differ  from  the 
other  molars  in  size  less  than  in  the  Caucasian  races." 
Prof.  Schaaffhausen  accounts  for  this  difference  between 
the  races  by  "the  posterior  dental  portion  of  the  jaw  being 
always  shortened  "  in  those  that  are  civilized,'^  and  this 
shortening  may,  I  presume,  be  safely  attributed  to  civil- 
ized men  habitually  feeding  on  soft,  cooked  food,  and 
thus  using  their  jaws  less.  I  am  informed  by  Mr,  Brace 
that  it  is  becoming  quite  a  common  practice  in  the  United 
States  to  relnove  some  of  the  molar  teeth  of  children,  as 
the  jaw  does  not  grow  large  enough  for  the  pei^fect  devel- 
opment of  the  normal  number. 

Willi  respect  to  the  alimentary  canal,  I  have  met  with 
an  account  of  only  a  single  rudiment,  namely,  the  vermi- 
form appendage  of  the  caecum.  The  ca?eum  is  a  branch 
or  diverticulum  of  the  intestine,  ending  in  a  cul-de-sac,  and 
it  is  extremely  long  in  many  of  the  lower  vegetable-feed- 
ing mammals.  In  the  marsupial  kaola  it  is  actually  more 
than  thrice  as  long  as  the  whole  body."  It  is  sometimes 
produced  into  a  long,  gradually-tapering  point,  and  is 
sometimes  constricted  in  parts.  It  appears  as  if,  in  conse- 
quence of  changed  diet  or  habits,  the  cnpcum  had  become 
much  shortened  in  various  animals,  the  vermiform  ajipond- 
age  being  left  as  a  rudiment  of  the  shortened  part.    That 

*'  Dr.  Webb,  '  Teeth  in  Man  and  the  Anthropoid  iVpes,'  ns  quoted  by 
Dr.  C.  Carter  Blake  in  '  Anthropological  Review,'  July,  1867,  p.  299, 

8'  Owen,  'Anatomy  of  Vertebrates,'  vol.  iii.  pp.  320,  .'521,  325. 

38  'On  the  primitive  Form- of  the  Skull,'  Eng.  translat.  in  'Anthro- 
pological Review,'  Oct.  1808,  p.  426. 

3*  Owen,  'Anatomy  of  Vertebrates,'  vol.  iii.  pp.  416,  434,  441. 


Chap.  I.]  RUDIMENTS.  27 

this  appendage  is  a  rudiment,  we  may  infer  fi-om  its  small 
size,  and  from  the  evidence  which  Prof.  Canestrini  '^  has 
collected  of  its  variability  in  man.  It  is  occasionally  quite 
absent,  or  again  is  largely  developed.  The  passage  is 
sometimes  completely  closed  for  half  or  two-thirds  of  its 
length,  with  the  terminal  part  consisting  of  a  flattened 
solid  expansion.  In  the  orang  this  appendage  is  long  and 
convolut  ed ;  in  man  it  arises  from  the  end  of  the  short 
caecum,  and  is  commonly  from  four  to  five  inches  in 
length,  being  only  about  the  third  of  an  inch  in  diameter. 
Not  only  is  it  useless,  but  it  is  sometimes  the  cause  of 
death,  of  which  fact  I  have  lately  heard  two  instances  ; 
this  is  due  to  small,  hard  bodies,  such  as  seeds,  entering  the 
passage  and  causing  inflammation.'® 

In  the  Quadrumana,  and  some  other  orders  of  mam- 
mals, especially  in  the  Carnivora,  there  is  a  passage  near 
the  lower  end  of  the  humerus,  called  the  supra-condyloid 
foramen,  through  which  the  great  nerve  of  the  fore-limb 
passes,  and  often  the  great  artery.  Now,  in  the  humerus 
of  man,  as  Dr.  Struthers  "  and  others  have  shown,  there 
is  generally  a  trace  of  this  passage,  and  it  is  sometimes 
fairly  well  developed,  being  formed  by  a  depending  hook- 
like process  of  bone,  completed  by  a  band  of  ligament. 
When  present  the  great  nerve  invariably  passes  through 
it,  and  this  clearly  indicates  that  it  is  the  homologue  and 
rudiment  of  the  supra-condyloid  foramen  of  the  lower  ani- 
mals.    Prof.  Turner  estimates,  as  he  informs  me,  that  it 

25  '  Annuario  della  Soc.  d.  Nat.'     Modena,  186Y,  p.  94. 

*^  M.  C.  Martins  ("De  I'Unite  Orgauique,"  in  'Revue  des  Deux 
Mondes,'  June  15,  1862,  p.  16),  aad  Hackel  ('Generelle  Morphologie,'  B. 
ii.  s.  278),  have  both  remarked  on  the  singular  fact  of  this  rudiment 
sometimes  causing  death. 

3'  'The  Lancet,'  Jan.  24,  1863,  p.  83.  Dr.  Knox,  'Great  Artists  and 
Anatomists,'  p.  63.  See  also  an  important  memoir  on  this  process  by 
Dr.  Grube,  m  the  '  Bulletin  de  I'Acad.  Imp.  de  St.  Petersbourg,  tom.  xii. 
1867,  p.  448.' 


28  THE   DESCENT   OF   MAN.  [Part  I. 

occurs  in  about  one  per  cent,  of  recent  skeletons;  but, 
during  ancient  times,  it  appears  to  have  been  much  more 
common.  Mr.  Busk  °'  has  collected  the  following  evi- 
dence on  this  head:  Prof.  Broca  "noticed  the  perforation 
in  four  and  a  half  per  cent,  of  the  arm-bones  collected  in 
the  '  Cimeti6re  du  Sud '  at  Paris ;  and  in  the  Grotto  of 
Orrony,  the  contents  of  which  are  referred  to  the  Bronze 
period,  as  many  as  eight  humeri  out  of  thirty-two  were 
perforated ;  but  this  extraordinary  proportion,  he  thinks, 
might  be  due  to  the  cavern  having  been  a  sort  of  '  family 
vault.'  Again,  M.  Dupont  found  thirty  per  cent,  of  per- 
forated bones  in  the  caves  of  the  Valley  of  the  Lesse,  be- 
longing to  the  Reindeer  period;  while  M.  Leguay,  in  a 
sort  of  dolmen  at  Argenteuil,  observed  twenty-live  per 
cent,  to  be  perforated  ;  and  M.  Pruner-Bey  found  twenty- 
six  per  cent,  in  the  same  condition  in  bones  from  ^'aur('•al. 
Nor  should  it  be  left  unnoticed  that  M.  Pruner-Bey  states 
that  this  condition  is  common  in  Guanche  skeletons." 
The  fact  that  ancient  races,  in  this  and  several  other 
cases,  more  frequently  present  structures  which  resemble 
those  of  the  lower  animals  than  do  the  modern  races,  is 
interesting.  On&  cliief  cause  seems  to  be  that  ancient 
races  stand  somewhat  nearer  than  modern  races  in  the 
long  line  of  descent  to  their  remote  animal-like  progeni- 
tors. 

The  OS  coccyx  in  man,  though  functionless  as  a  tail, 
plainly  represents  this  part  in  other  vertebrate  animals. 
At  an  early  embryonic  period  it  is  free,  and,  as  we  have 
seen,  projects  beyond  the  lower  extremities.  In  certain 
rare  and  anomalous  cases  it  has.  been  known,  according  to 
Isidore  Geoffroy  St.-Hilaire  and  others,^*  to  form  a  small 

38  "  On  the  Caves  of   Gibraltar,"  '  Transact.  Intcrnat.   Congress  of 
Prehist.  Arch.'     Third  Session,  1869,  p.  54. 

3*  Quatrefages   has   lately  collected    the   evidence    on   this   subject. 
Kcvue  des  Cours  Scientifiques,'  1867-68,  p.  625. 


Chap.  I.]  RUDIMENTS.  29 

external  rudiment  of  a  tail.  The  os  coccyx  is  short,  usu- 
ally including  only  four  vertebrae ;  and  these  are  in  a  rudi- 
mental  condition,  for  they  consist,  with  the  exception  of 
the  basal  one,  of  the  centrum  alone.*"  They  are  furnished 
with  some  small  muscles  ;  one  of  which,  as  I  am  informed 
by  Prof  Turner,  has  been  expressly  described  by  Theile  as 
a  rudimentary  repetition  of  the  extensor  of  the  tail,  which 
is  so  largely  developed  in  many  mammals. 

The  spinal  cord  in  man  extends  only  as  far  downward 
as  the  last  dorsal  or  first  lumbar  vertebra ;  but  a  thread- 
like structure  {t\iQjilum  terminale)  runs  down  the  axis  of 
the  sacral  part  of  the  spinal  canal,  and  even  along  the  back 
of  the  coccygeal  bones.  The  upper  part  of  this  filament, 
as  Prof.  Turner  informs  me,  is  undoubtedly  homologous 
with  the  spinal  cord ;  but  the  lower  part  apparently  con- 
sists merely  of  the  pia  mater,  or  vascular  investing  mem- 
brane. Even  in  this  case  the  os  coccyx  may  be  said  to 
possess  a  vestige  of  so  important  a  structure  as  the  spinal 
cord,  though  no  longer  enclosed  within  a  bony  canal.  The 
following  fact,  for  which  I  am  also  indebted  to  Prof. 
Turner,  shows  how  closely  the  os  coccyx  corresponds  with 
the  true  tail  in  the  lower  animals :  Luschka  has  recently 
discovered  at  the  extremity  of  the  coccygeal  bones  a  very 
peculiar  convoluted  body,  which  is  continuous  with  the 
middle  sacral  artery ;  and  this  discovery  led  Krause  and 
Meyer  to  examine  the  tail  of  a  monkey  (Macacus)  and  of 
a  cat,  in  both  of  which  they  found,  though  not  at  the  ex- 
tremity, a  similarly  convoluted  body. 

The  reproductive  system  ofiers  various  rudimentary 
structures ;  but  these  diifer  in  one  important  respect  from 
the  foregoing  cases.  We  are  not  here  concerned  with  a 
vestige  of  a  part  which  does  not  belong  to  the  species  in 
an  efficient  state  ;  but  with  a  part  which  is  always  present 
and  efiicient  in  the  one  sex,  being  represented  in  the  other 

^  Owen,  'On  the  Xature  of  Limbs,'  1849,  p.  114 


30  THE   DESCENT   OF  MAN.  [Part  1. 

by  a  mere  rudiment.  Nevertheless,  the  occurrence  of 
such  rudiments  is  as  difficult  to  explain  on  the  belief  of  the 
separate  creation  of  each  species,  as  in  the  foregoing  cases. 
Hereafter  I  shall  have  to  recur  to  these  rudiments,  and 
shall  show  that  their  presence  generally  depends  merely  on 
inheritance ;  namely,  on  parts  acquired  by  one  sex  having 
been  partially  transmitted  to  the  other.  Here  I  will  only 
give  some  instances  of  such  rudiments.  It  is  Avell  known 
that  in  the  males  of  all  mammals,  including  man,  rudi- 
mentary mammae  exist.  These,  in  several  instances,  have 
become  well  developed,  and  have  yielded  a  copious  supply 
of  milk.  Their  essential  identity  in  the  two  sexes  is  like- 
wise shown  by  their  occasional  sympathetic  enlargement 
in  both  during  an  attack  of  the  measles.  The  vesicula 
prostratica,  which  has  been  observed  in  many  male  mam- 
mals, is  now  universally  acknowledged  to  be  the  homo- 
logue  of  the  female  uterus,  together  with  the  connected 
passage.  It  is  impossible  to  read  Leuckart's  able  descrip- 
tion of  this  organ,  and  his  reasoning,  without  admitting 
the  justness  of  his  conclusion.  This  is  especially  clear  in 
the  case  of  those  mammals  in  which  the  true  female  ute- 
rus bifurcates,  for  in  the  males  of  these  the  vesicula  like- 
wise bifurcates."  Some  additional  rudimentary  structures 
belonging  to  the  reproductive  system  might  here  have 
been  adduced." 

The  bearing  of  the  three  great  classes  of  facts  now 
given  is  unmistakable.  But  it  would  be  superfluous  here 
fully  to  recapitulate  the  line  of  argument  given  in  detail 

<>  Lcuckart,  in  Todd's  'Cyclop,  of  Aniit.'  1849-'52,  vol.  iv.  p.  1415. 
In  man  this  organ  is  only  from  three  to  six  lines  in  length,  but,  like  so 
many  other  rudimentary  parts,  it  is  variable  in  development  as  well  as  in 
other  characters. 

*^  See,  on  this  subject,  Owen,  '  Anatomy  of  Vertebrates,'  vol  iii.  pp. 
675,  67G,  706. 


Chap.  I.]  RUDIMENTS.  31 

in  my  '  Origin  of  Species.'  The  homological  construction 
of  the  whole  frame  in  the  members  of  the  same  class  is 
intelligible,  if  we  admit  their  descent  from  a  common  pro- 
genitor, together  with  their  subsequent  adaptation  to  di- 
versified conditions.  On  any  other  view  the  similarity  of 
pattern  between  the  hand  of  a  man  or  monkey,  the  foot  of 
a  horse,  the  flipper  of  a  seal,  the  wing  of  a  bat,  etc.,  is  ut- 
terly inexplicable.  It  is  no  scientific  explanation  to  assert 
that  they  have  all  been  formed  on  the  same  ideal  plan. 
With  respect  to  development,  we  can  clearly  understand, 
on  the  principle  of  variations  supervening  at  a  rather  late 
embryonic  period,  and  being  inherited  at  a  corresponding 
period,  ho"w  it  is  that  the  embryos  of  wonderfully  difterent 
forms  should  still  retain,  more  or  less  perfectly,  the  struct- 
ure of  their  common  progenitor.  No  other  explanation 
has  ever  been  given  of  the  marvellous  fact  that  the  embryo 
of  a  man,  dog,  seal,  bat,  reptile,  etc.,  can  at  first  hardly  be  / 
distinguished  from  each  other.  In  order  to  understand 
the  existence  of  rudimentary  organs,  we  have  only  to  sup- 
pose that  a  former  progenitor  possessed  the  parts  in  ques- 
tion in  a  perfect  state,  and  that  under  changed  habits  of 
life  they  became  greatly  reduced,  either  from  simple  dis- 
use, or  through  the  natural  selection  of  those  individuals 
which  were  least  encumbered  with  a  superfluous  part,  aided 
by  the  other  means  previously  indicated. 

Thus  we  can  understand  how  it  has  come  to  pass  that 
man,  and  all  other  vertebrate  animals,  have  been  con- 
structed on  the  same  general  model,  why  they  pass  through 
the  same  early  stages  of  development,  and  why  they  re- 
tain certain  rudiments  in  common.  Consequently  we 
ought  frankly  to  admit  their  community  of  descent ;  to 
take  any  other  view,  is  to  admit  that  our  own  structure,  and 
that  of  all  the  animals  around  us,  is  a  mere  snare  laid  to 
entrap  our  judgment.  This  conclusion  is  greatly  strength- 
ened, if  we  look  to  the  members  of  the  whole  animal  se- 


32  THE   DESCENT   OF  MAN.  [Part  1, 

ries,  and  consider  the  evidence  derived  from  their  affinities 
or  classification,  their  geographical  distribution,  and  geo- 
logical succession.  It  is  only  our  natural  prejudice,  and 
that  arrogance  which  made  our  forefathers  declare  that 
they  were  descended  from  dcmi-gods,  wliich  lead  us  to 
demur  to  this  conclusion.  But  the  time  will  before  long 
come  when  it  will  be  thought  wonderful  that  naturalists, 
who  were  well  acquainted  with  the  comparative  structure 
and  development  of  man  and  other  mammals,  should  have 
believed  that  each  was  the  work  of  a  separate  act  of  crea- 
tion. 


Chap.  II.  ]  MENTAL   POWERS.  .  33 


CHAPTER    II. 

COMPAEISOIf    OF   THE    MEISTTAL     POWEES    OF     MAN    AND    THE 
LOWEE    ANIMALS. 

The  Difference  in  Mental  Power  between  the  Highest  Ape  and  the  Lowest 
Savage,  immense. — Certain  Instincts  in  common. — The  Emotions. — 
Cm-iosity. — Imitation. — Attention. — Memory. — Imagination. — Eeason. 
— Progressive  Improvement. — Tools  and  Weapons  used  by  Animals. 
— Language. — Self-Consciousness. — Sense  of  Beauty. — Belief  in  God, 
Spiritual  Agencies,  Superstitions. 

We  have  seen  in  the  last  chapter  that  man  bears  in  his 
bodily  structure  clear  traces  of  his  descent  from  some  lower 
form ;  but  it  may  be  urged  that,  as  man  differs  so  greatly 
in  his  mental  power  from  all  other  animals,  there  must  be 
some  error  in  this  conclusion.  No  doubt  the  difference  in 
this  respect  is  enormous,  even  if  we  compare  the  mind  of 
one  of  the  lowest  savages,  who  has  no  words  to  express 
any  number  higher  than  four,  and  who  uses  no  abstract 
terms  for  the  commonest  objects  or  affections,'  with  that 
of  the  most  highly-organized  ape.  The  difference  would, 
no  doubt,  still  remain  immense,  even  if  one  of  the  higher 
apes  had  been  improved  or  civilized  as  much  as  a  dog  has 
been  in  comparison  with  its  parent-form,  the  wolf  or  jackal. 
The  Fuegians  rank  among  the  lowest  barbarians  ;  but  I  was 
continually  struck  with  surprise  how  closely  the  three  na- 

'  See  the  evidence  on  these  points,  as  given  by  Lubbock,  '  Prehistoric 
Times,'  p.  354,  etc. 


34  THE   DESCENT   OF  MAN.  [Part  1. 

lives  on  board  H.  M.  S.  "  Beagle,"  who  had  lived  some 
years  in  England,  and  could  talk  a  little  English,  resem- 
bled us  in  disposition,  and  in  most  of  our  mental  faculties. 
If  no  organic  being  excepting  man  had  possessed  any  men- 
tal ])owcr,  or  if  his  powers  had  been  of  a  wholly  different 
nature  from  those  of  the  lower  animals,  then  we  should 
never  have  been  able  to  convince  ourselves  that  our  high 
faculties  had  been  gradually  developed.  But  it  can  be 
clearly  shown  that  there  is  no  fundamental  difference  of 
this  kind.  We  must  also  admit  that  there  is  a  much 
wider  interval  in  mental  power  between  one  of  the  lowest 
fishes,  as  a  lamprey  or  lancelet,  and  one  of  the  higher  apes, 
than  between  an  ape  and  man ;  yet  this  immense  interval 
is  filled  up  by  numberless  gradations. 

Nor  is  the  difference  slight  in  moral  disposition  between 
a  barbarian,  such  as  the  man  described  by  the  old  navi- 
gator Byron,  who  dashed  his  child  on  the  rocks  for  drop- 
ping a  basket  of  sea-urchins,  and  a  Howard  or  Clarkson ; 
and  in  intellect,  between  a  savage  who  does  not  use  any 
abstract  terms,  and  a  Newton  or  Shakespeare.  Differences 
of  this  kind  between  the  highest  men  of  the  highest  races 
and  the  lowest  savages,  are  connected  by  the  finest  grada- 
tions. Therefore  it  is  possible  that  they  might  pass  and 
be  developed  into  each  other. 

My  object  in  this  chapter  is  solely  to  show  that  there 
is  no  fundamental  difference  between  man  and  the  higher 
mammals  in  their  jncntal  faculties.  Each  division  of  the 
subject  might  have  beeil  extended  into  a  separate  essay, 
but  must  here  be  treated  briefly.  As  no  classification  of 
the  mental  powers  has  been  universally  accepted,  I  shall 
arrange  my  remarks  in  the  order  most  convenient  for  my 
purpose,  and  will  select  those  facts  which  have  most  struck 
me,  with  the  hope  that  they  may  produce  some  effect  on 
the  reader. 

With  respect  to  animals  very  low  in  the  scale,  I  shall 


Chap.  II.]  MENTAL  POWERS.  35 

have  to  give  some  additional  facts  under  Sexual  Selection, 
showing  that  their  mental  powers  are  higher  than  might 
have  been  expected.  The  variability  of  the  faculties  in 
the  individuals  of  the  same  species  is  an  important  point 
for  us,  and  some  few  illustrations  will  here  be  given.  But 
it  would  be  superfluous  to  enter  into  many  details  on  this 
head,  for  I  have  found,  on  frequent  inquiry,  that  it  is  the 
unanimous  opinion  of  all  those  who  have  long  attended  to 
animals  of  many  kinds,  including  birds,""that  the  individuals 
differ  greatly  in  every  mental  characteristic.  In  what 
manner  the  mental  powers  were  first  developed  in  the  low- 
est organisms,  is  as  hopeless  an  inquiry  as  how  life  first 
originated.  These  are  problems  for  the  distant  future,  if 
they  are  ever  to  be  solved  by  man. 

As  man  possesses  the  same  senses  with  the  lower  ani- 
mals, his  fundamental  intuitions  must  be  the  same.  Man 
has  also  some  few  instincts  in  common,  as  that  of  self-pres- 
ervation, sexual  love,  the  love  of  the  mother  for  her  new- 
born offspring,  the  power  possessed  by  the  latter  of  suck- 
ing, and  so  forth.  But  man,  perhaps,  has  somewhat  fewer 
instincts  than  those  possessed  by  the  animals  which  come 
next  to  him  in  the  series.  The  orang  in  the  Eastern  isl- 
ands, and  the  chimpanzee  in  Africa,  build  platforms,  on 
which  they  sleep ;  and,  as  both  species  follow  the  same 
habit,  it  might  be  argued  that  this  was  due  to  instinct, 
but  we  cannot  feel  sure  that  it  is  not  the  result  of  both 
animals  having  similar  wants,  and  possessing  similar  pow- 
ers of  reasoning.  These  apes,  as  we  may  assume,  avoid 
the  many  poisonous  fruits  of  the  tropics,  and  man  has  no 
such  knowledge  ;  but  as  our  domestic  animals,  when  taken 
to  foreign  lands,  and  when  first  turned  out  in  the  spring, 
often  eat  poisonous  herbs,  which  they  afterward  avoid,  we 
cannot  feel  sure  that  tlie  apes  do  not  leai*n  from  their  own 
experience,  or  from  that  of  their  parents,  what  fruits  to 
select.     It  is,  however,  certain,  as  we  shall  presently  see, 


36  THE   DESCENT   OF   MAN.  [Part  I. 

that  apes  have  an  instinctive  dread  of  serpents,  and  prob- 
ably of  other  dangerous  animals. 

The  fewness  and  the  comparative  simplicity  of  the  in- 
stincts in  the  liigher  animals  are  remarkable  in  contrast  with 
those  of  the  lower  animals.  Cuvier  maintained  that  instinct 
and  intelligence  stand  in  an  inverse  ratio  to  each  other  ;  and 
some  have  thought  that  the  intellectual  faculties  of  the 
higher  animals  have  been  gi-adually  developed  from  their 
instincts.  ButPouchet,  in  an  interesting  essay,^  has  shown 
that  no  such  inverse  ratio  really  exists.  Those  insects 
which  possess  the  most  wonderful  instincts  are  certainly 
the  most  intelligent.  In  the  vertebrate  series,  the  least 
intelligent  members,  namely  fishes  and  amphibians,  do  not 
possess  complex  instincts ;  and  among  mammals  the  ani- 
mal most  remarkable  for  its  instincts,  namely  the  beaver, 
is  highly  intelligent,  as  Avill  be  admitted  by  every  one 
who  has  read  Mr.  Morgan's  excellent  account  of  this  animal.' 

Although  the  first  dawnings  of  intelligence,  according 
to  Mr.  Herbert  Spencer,*  have  been  developed  through  the 
multiplication  and  coordination  of  reflex  actions,  and  al- 
though many  of  the  simpler  instmcts  graduate  into  actions 
of  this  kind,  and  can  hardly  be  distinguished  from  them, 
as  in  the  case  of  young  animals  sucking,  yet  the  more 
complex  instincts  seem  to  have  originated  independently 
of  intelligence.  I  am,  however,  far  from  wishing  to  deny 
that  instinctive  actions  may  lose  their  fixed  and  untaught 
character,  and  be  ivplaced  by  others  performed  by  the  aid 
of  the  free  will.  On  the  other  hand,  some  intelligent  ac- 
tions— as  when  birds  on  oceanic  islands  first  learn  to  avoid 
man — after  being  performed  during  many  generations,  be- 
come converted  into  instincts,  and  are  inherited.     They 

*  '  L'Instinct  chez  Ics  Inscctcs.'  '  Revue  des  Deux  Mondes,'  Feb. 
1870,  p.  690. 

^  '  The  American  Beaver  and  his  Works,'  1868. 

«  'The  Principles  of  Psychology,'  2d  edit.  1870,  pp.  418-413. 


Chap.  IL]  MENTAL   POWERS.  37 

may  then  be  said  to  be  degraded  in  character,  for  they  are 
no  longer  performed  through  reason  or  from  experience. 
But  the  greater  number  of  the  more  complex  instincts  ap- 
pear to  have  been  gained  in  a  wholly  different  manner, 
through  the  natural  selection  of  variations  of  simpler  in- 
stinctive actions.  Such  variations  appear  to  arise  from 
the  same  unknown  causes  acting  on  the  cerebral  organiza- 
tion, which  induce  slight  variations  or  individual  differ- 
ences in  other  parts  of  the  body;  and  these  variations, 
owing  to  our  ignorance,  are  often  said  to  arise  sponta- 
neously. We  can,  I  think,  come  to  no  other  conclusion 
with  respect  to  the  origin  of  the  more  complex  instincts, 
when  we  reflect  on  the  marvellous  instincts  of  sterile 
worker-ants  and  bees,  which  leave  no  offspring  to  inherit 
the  effects  of  experience  and  of  modified  habits. 

Although  a  high  degree  of  intelligence  is  certainly 
compatible  with  the  existence  of  complex  instincts,  as  we 
see  in  the  insects  just  named  and  in  the  beaver,  it  is  not 
improbable  that  they  may  to  a  certain  extent  interfere 
with  each  other's  development.  Little  is  known  about 
the  functions  of  the  brain,  but  we  can  perceive  that,  as 
the  intellectual  powers  become  highly  developed,  the  va- 
rious parts  of  the  brain  must  be  connected  by  the  most 
intricate  channels  of  intercommunication  ;  and  as  a  conse- 
quence each  separate  part  would,  perhaps,  tend  to  be- 
come less  well  fitted  to  answer  in  a  definite  and  uniform, 
that  is  instinctive,  manner  to  particular  sensations  or  as- 
sociations. 

I  have  thought  this  digression  worth  giving,  because 
we  may  easily  underrate  the  mental  powers  of  the  higher 
animals,  and  especially  of  man,  when  we  compare  their 
actions,  founded  on  the  memory  of  past  events,  on  fore- 
sight, reason,  and  imagination,  with  exactly  similar  actions 
instinctively  performed  by  the  lower  animals ;  in  this  lat- 
ter case,  the  capacity  of  performing  such  actions  having 


38  THE  DESCENT   OF  MAN.  [Part  I. 

been  gained,  step  by  step,  through  the  variability  of  the 
mental  organs  and  natural  selection,  without  any  conscious 
intelligence  on  the  part  of  the  animal  during  each  succes- 
sive generation.  No  doubt,  as  Mr.  Wallace  has  argued,' 
much  of  the  intelligent  work  done  by  man  is  due  to  imita- 
tion, and  not  to  reason  ;  but  there  is  this  great  difference 
between  his  actions  and  many  of  those  performed  by  the 
lower  animals,  namely,  that  man  cannot,  on  his  first  trial, 
make,  for  instance,  a  stone  liatchet  or  a  canoe,  tli  rough  his 
power  of  imitation.  He  has  to  learn  his  work  by  practice ; 
a  beaver,  on  the  other  hand,  can  make  its  dam  or  canal, 
and  a  bird  its  nest,  as  well,  or  nearly  as  well,  the  first  time 
it  tries,  as  Av^hen  old  and  experienced. 

To  return  to  our  immediate  subject :  the  lower  animals, 
like  man,  manifestly  feel  pleasure  and  pain,  happiness  and 
misery.  Happiness  is  never  better  exhibited  than  by 
young  animals,  such  as  puppies,  kittens,  lambs,  etc.,  when 
playing  together,  like  our  own  children.  Even  insects 
play  together,  as  has  been  described  by  that  excellent  ob- 
server, P.  Huber,"  who  saw  ants  chasing  and  pretending  to 
bite  each  other,  like  so  many  puppies. 

Tlie  fact  that  the  lower  animals  are  excited  by  the  same 
emotions  as  ourselves  is  so  well  established,  that  it  will  not 
be  necessary  to  weary  the  reader  by  many  details.  Terror 
acts  in  the  same  manner  on  them  as  on  us,  causing  the 
muscles  to  tremble,  the  heart  to  palpitate,  the  sphincters 
to  be  relaxed,  and  the  hair  to  stand  on  end.  Suspicion, 
the  offspring  of  fear,  is  eminently  characteristic  of  most 
wild  animals.  Courage  and  timidity  are  extremely  va- 
riable qualities  in  the  individuals  of  the  same  species, 
as  is  plainly  seen  in  our  dogs.  Some  dogs  and  horses 
are  ill-tempered,  and  easily  turn  sulky ;  others  are  good- 
tempered;   and  these    qualities    are   certainly    inherited. 

*  'Contributions  to  the  Theory  of  Natural  Selection,'  1870,  p.  212. 
■  6 '  Recherches  sur  les  Mceurs  des  Fourmis,'  1810,  p.  173. 


Chap.  II.]  MENTAL   POWERS.  39 

Every  one  knows  how  liable  animals  are  to  furious  rage, 
and  how  plainly  they  show  it.  Many  anecdotes,  probably 
true,  have  been  published  on  the  long-delayed  and  artful 
revenge  of  various  animals.  The  accurate  Rengger  and 
Brehm'  state  that  the  American  and  African  monkeys 
which  they  kept  tame,  certainly  revenged  tliemselves. 
The  love  of  a  dog  for  his  master  is  notorious  ;  in  the 
agony  of  death  he  has  been  known  to  caress  his  master, 
and  every  one  has  heard  of  the  dog  suflering  under  vivi- 
section, who  licked  the  hand  of  the  operator ;  this  man, 
unless  he  had  a  heart  of  stone,  must  have  felt  remorse  to 
the  last  hour  of  his  life.  As  Whewell  *  has  remarked, 
"  who  that  reads  the  touching  instances  of  maternal  affec- 
tion, related  so  often  of  the  women  of  all  nations,  and  of 
the  females  of  all  animals,  can  doubt  that  the  principle  of 
action  is  the  same  in  the  two  cases  ?  " 

"We  see  maternal  affection  exhibited  in  the  most  trifling 
details ;  thus  Rengger  observed  an  American  monkey  (a 
Cebus)  carefully  driving  away  the  flies  which  plagued  her 
infant ;  and  Duvaucel  saw  a  Hylobates  washing  the  faces 
of  her  young  ones  in  a  stream.  So  intense  is  the  grief  of 
female  monkeys  for  the  loss  of  their  young,  that  it  inva- 
riably caused  the  death  of  certain  kinds  kept  under  con- 
finement by  Brehm  in  North  Africa.  Orphan-monkeys  were 
always  adopted  and  carefully  guarded  by  the  other  mon- 
keys, both  males  and  females.  One  female  baboon  had  so 
capacious  a  heart,  that  she  not  only  adopted  young  mon- 
keys of  other  species,  but  stole  young  dogs  and  cats,  which 
she  continually  carried  about.  Her  kindness,  however,  did 
not  go  so  far  as  to  share  her  food  with  her  adopted  off- 
spring, at  which  Brehm  was  surprised,  as  his  monkeys  al- 

'  All  the  following  statements,  given  on  the  authority  of  these  two 
naturalists,  are  taken  from  Rengger's  '  Naturges.  der  Saugethiere  von 
Paraguay,'  1830,  s.  41-57,  and  from  Brehm's  '  Thierleben,'  B.  i.  s.  10-87. 

^  '  Bridgewater  Treatise,'  p.  263. 


40  THE   DESCENT   OF  MAN.  [Part  L 

ways  divided  every  thing  quite  fairly  with  their  own 
young  ones.  An  adopted  kitten  scratched  the  above-men- 
tioned affectionate  baboon,  who  certainly  had  a  line  intel- 
lect, for  she  was  niueli  astonished  at  being  scratcljed,  and 
immediately  examined  the  kitten's  feet,  and  without  more 
ado  bit  off  the  claws.  In  the  Zoological  Gardens,  I  heard 
from  the  keeper  that  an  old  baboon  [C.  chacma)  had 
adopted  a  Rhesus  monkey ;  but  when  a  young  drill  and 
mandrill  were  placed  in  the  cage,  she  seemed  to  perceive 
that  these  monkeys,  though  distinct  species,  were  her 
nearer  relatives,  for  she  at  once  rejected  the  Rhesus  and 
adopted  both  of  them.  The  young  Rhesus,  as  I  saw,  was 
greatly  discontented  at  being  thus  rejected,  and  it  would, 
like  a  naughty  child,  annoy  and  attack  the  young  drill 
and  mandrill  whenever  it  could  do  so  with  safety ,  this 
conduct  exciting  great  indignation  in  the  old  baboon. 
Monkeys  will  also,  according  to  Brehm,  defend  their  mas- 
ter when  attacked  by  any  one,  as  well  as  dogs  to  whom 
they  are  attached,  from  the  attacks  of  other  dogs.  But 
we  here  trench  on  the  subject  of  sympathy,  to  which  I 
shall  recur.  Some  of  Brehm's  monkeys  took  much  de- 
light in  teasing,  in  various  ingenious  ways,  a  certain  old 
dog  whom  they  disliked,  as  well  as  other  animals. 

Most  of  the  more  complex  emotions  are  common  to  the 
higher  animals  and  ourselves.  Every  one  has  seen  how 
jealous  a  dog  is  of  his  master's  affection,  if  lavished  on 
any  other  creature ;  and  I  have  observed  the  same  fact 
with  monkeys.  This  shows  that  animals  not  only  love, 
but  have  the  desire  to  be  loved.  Animals  manifestly  feel 
emulation.  They  love  approbation  or  praise  ;  and  a  dog 
carrying  a  basket  for  his  master  exhibits  in  a  high  degree 
self-complacency  or  pride.  There  can,  I  think,  be  no  doubt 
that  a  dog  feels  shame,  as  distinct  from  fear,  and  some- 
thing very  like  modesty  when  begging  too  often  for  food. 
A  great  dog  scorns  the  snarling  of  a  little  dog,  and  this 


Chap.  II.]  MEXTAL   POWERS.  41 

may  be  called  magnanimity.  Several  observers  have 
stated  that  monkeys  certainly  dislike  being  laughed  at ; 
and  they  sometimes  invent  imaginary  oiFences.  In  the 
Zoological  Gardens  I  saw  a  baboon  who  always  got  into 
a  furious  rage  when  his  keeper  took  out  a  letter  or  book 
and  read  it  aloud  to  him ;  and  his  rage  was  so  violent  that, 
as  I  witnessed  on  one  occasion,  he  bit  his  own  leg  till  the 
blood  flowed. 

We  will  now  turn  to  the  more  intellectual  emotions 
and  faculties,  which  are  very  important,  as  forming  the 
basis  for  the  development  of  the  higher  mental  powers. 
Animals   manifestly   enjoy   excitement    and   suffer   from 
ennui,  as  may  be  seen  with  dogs,  and,  according  to  Reng- 
ger,  with  monkeys.     All  animals  feel  wonder,  and  many 
exhibit  curiosity.     They  sometimes  suffer  from  this  latter 
quality,  as  when  the  hunter  plays  antics  and  thus  attracts 
them ;  I  have  witnessed  this  with  deer,  and  so  it  is  with 
the  wary  chamois,  and  with  some  kinds  of  wild-ducks. 
Brehm  gives  a  curious  account  of  the  instinctive  dread 
which  his  monkeys  exhibited  toward  snakes ;    but  their 
curiosity  was  so  great  that  they  could  not  desist  from  oc- 
casionally satiating  their  horror  in  a  most  human  fashion, 
by  lifting  up  the  lid  of  the  box  in  which  the  snakes  were 
kept.     I  was  so  much  surprised  at  his  account,  that  I  took 
a  stuffed  and  coiled-up  snake  into  the  monkey-house  at  tlie 
Zoological  Gardens,  and  the  excitement  thus  caused  was 
one  of  the  most  curious  spectacles  which  I  ever  beheld. 
Three  species  of  Cercopithecus  were  the  most  alarmed ; 
they  dashed  about  their  cages  and  uttered  sharp  signal- 
cries  of  danger,  which  were   understood   by  the   other 
monkeys.     A  few  young  monkeys  and  one  old  Anubis 
baboon  alone  took  no  notice  of  the  snake.     I  then  placed 
the  stuffed  specimen  on  the  ground  in  one  of  the  larger 
compartments.     After  a  time  all  the  monkeys  collected 
round  it  in  a  large  circle,  and,  staring  intently,  presented 
3 


42  THE   DESCENT   OF  liLVN.  f  Paut  L 

a  most  ludicrous  apjicarance.  They  became  extremely 
nervous  ;  so  that  when  a  wooden  ball,  with  which  they 
were  familiar  as  a  plaything,  was  accidentally  moved  in 
the  straw,  under  which  it  was  partly  hidden,  they  all  in- 
stantly started  away.  These  monkeys  behaved  very  dif- 
ferently when  a  dead  fish,  a  mouse,  and  some  other  new 
objects,  were  placed  in  their  cages ;  for,  though  at  first 
frightened,  they  soon  approached,  handled  and  examined 
them.  I  then  placed  a  live  snake  in  a  paper  bag,  with 
the  mouth  loosely  closed,  in  one  of  the  larger  compart- 
ments. One  of  the  monkeys  immediately  approached, 
cautiously  opened  the  bag  a  little,  peeped  in,  and  in- 
stantly dashed  away.  Then  I  witnessed  what  Brchm  has 
described,  for  monkey  after  monkey,  with  head  raised 
high  and  turned  on  one  side,  could  not  resist  taking  mo- 
mentary pecjjs  into  the  upright  bag,  at  the  dreadful  object 
lying  quiet  at  the  bottom.  It  would  almost  appear  as  if 
monkeys  had  some  notion  of  zoological  affinities,  for  those 
kept  by  Brehm  exhibited  a  strange,  though  mistaken,  in- 
stinctive dread  of  innocent  lizards  and  frogs.  An  orang, 
also,  has  been  known  to  be  much  alarmed  at  the  first 
sight  of  a  turtle.* 

The  principle  of  Imitation  is  strong  in  man,  and  espe- 
cially in  man  in  a  barbarous  state.  Desor"  has  remarked 
that  no  animal  voluntarily  imitates  an  action  performed 
by  man,  imtil  in  the  ascending  scale  we  come  to  monkeys, 
which  are  well  known  to  be  ridiculous  mockers.  Animals, 
however,  sometimes  imitate  each  others'  actions :  thus  two 
species  of  wolves,  which  had  been  reared  by  dogs,  learned 
to  bark,  as  does  sometimes  the  jackal,"  but  whether  this 
can   be   called  voluntary  imitation  is   another   question. 

9  W.  C.  L.  Martin,  '  Nat.  Hist,  of  Mammalia,'  1841,  p.  405. 
">  Quoted  by  Vogt,  'Mcmoire  surlcs  Microc6phales,'  1867,  p.  168. 
"  '  The  Variation  of  Animals  and  Plants  under  Domestication,'  vol  i. 
p.  27. 


Chap.   II.]  MENTAL   POAVERS.  43 

From  one  account  which  I  have  read,  there  is  reason  to 
believe  that  puppies  nursed  by  cats  sometimes  learn  to 
lick  their  feet  and  thus  to  clean  their  faces  :  it  is  at  least 
certain,  as  I  hear  from  a  perfectly  trustworthy  friend,  that 
some  dogs  behave  in  this  manner.  Birds  imitate  the 
songs  of  their  parents,  and  sometimes  those  of  other 
birds ;  and  parrots  are  notorious  imitators  of  any  sound 
which  they  often  hear. 

Hardly  any  faculty  is  more  important  for  the  intellec- 
tual progress  of  man  than  the  power  of  Attention.  Ani- 
mals clearly  manifest  this  power,  as  when  a  cat  watches 
by  a  hole  and  prepares  to  spring  on  its  prey.  Wild  animals 
sometimes  become  so  absorbed  when  thus  engaged,  that 
they  may  be  easily  approached,  Mr.  Bartlett  has  given 
me  a  curious  proof  how  variable  this  faculty  is  in  mon- 
keys. A  man  who  trains  monkeys  to  act  used  to  purchase 
common  kinds  from  the  Zoological  Society  at  the  price  of 
five  pounds  for  each ;  but  he  offered  to  give  double  the 
price,  if  he  might  keep  three  or  four  of  them  for  a  few 
days,  in  order  to  select  one.  When  asked  how  he  could 
possibly  so  soon  learn  whether  a  particular  monkey  would 
turn  out  a  good  actor,  he  answered  that  it  all  depended 
on  their  power  of  attention.  If  when  he  was  talking  and 
explaining  any  thing  to  a  monkey,  its  attention  was  easily 
distracted,  as  by  a  fly  on  the  wall  or  other  trifling  object, 
the  case  was  hopeless.  If  he  tried  by  punishment  to 
make  an  inattentive  monkey  act,  it  turned  sulky.  On 
the  other  hand,  a  monkey  which  carefully  attended  to  him 
could  always  be  trained. 

It  is  almost  superfluous  to  state  that  animals  have  ex- 
cellent Memories  for  persons  and  places.  A  baboon  at  the 
Cape  of  Good  Hope,  as  I  have  been  informed  by  Sir  An- 
drew Smith,  recognized  him  with  joy  after  an  absence  of 
nine  months.  I  had  a  dog  who  was  savage  and  averse  to 
all  strangers,  and  I  purposely  tried  his  memory  after  an 


44  THE   DESCENT   OF  MAN.  [Part.  I. 

absence  of  five  years  and  two  days.  I  went  near  the  sta- 
ble where  he  lived,  and  shouted  to  him  in  my  old  manner; 
he  showed  no  joy,  but  instantly  followed  me  out  walking 
and  obeyed  me,  exactly  as  if  I  had  parted  with  him  only 
half  an  hour  before.  A  train  of  old  associations,  dormant 
during  five  years,  had  thus  been  instantaneously  awakened 
in  his  mind.  Even  ants,  as  P.  Huber  "  has  clearly  shown, 
recognized  their  fellow-ants  belonging  to  the  same  com- 
munity after  a  separation  of  four  months.  Animals  can 
certainly  by  some  means  judge  of  the  intervals  of  time 
between  recurrent  events. 

The  Imagination  is  one  of  the  highest  prerogatives  of 
man.  By  this  faculty  he  imites,  independently  of  the  will, 
former  images  and  ideas,  and  thus  creates  brilliant  and 
novel  results.  A  poet,  as  Jean  Paul  Richter  remarks,*' 
"  who  must  reflect  whether  he  shall  make  a  character  say 
yes  or  no — to  the  devil  with  him ;  he  is  only  a  stupid 
corpse."  Dreaming  gives  us  the  best  notion  of  this 
power ;  as  Jean  Paul  again  says,  "  The  dream  is  an  invol- 
untary art  of  poetry."  The  value  of  the  products  of  our 
imagination  depends  of  course  on  the  number,  accuracy, 
and  clearness  of  our  impressions  ;  on  our  judgment  and 
taste  in  selecting  or  rejecting  the  involuntary  combina- 
tions, and  to  a  certain  extent  on  our  power  of  voluntarily 
combining  them.  As  dogs,  cats,  horses,  and  probably  all 
the  higher  animals,  even  birds,  as  is  stated  on  good  au- 
thority," have  vivid  dreams,  and  this  is  shown  by  their 
movements  and  voice,  we  must  admit  that  they  possess 
some  power  of  imagination. 

Of  all  the  faculties  of  the  human  mind,  it  will,  I  pre- 
sume, be  admitted  that  Heason  stands  at  the  summit. 

'*  'Lc3  Moeurs  dcs  Founnis,'  ISIO,  p.  150. 

'2  Quoted  in  Dr.  Maudsley's  'Physiology  and  Pathology  of  Mind,' 
1808,  pp.  19,  220. 

"  Dr.  Jerdon,  'Birds  of  India,'  vol  i.  1862   p.  ixL 


Chap,  n.]  MENTAL  POWEES.  46 

Few  persons  any  longer  dispute  that  animals  possess  some 
power  of  reasoning.  Animals  may  constantly  be  seen  to 
pause,  deliberate,  and  resolre.  It  is  a  significant  fact, 
that  the  more  the  habits  of  any  particular  animal  are 
studied  by  a  naturalist,  the  more  he  attributes  to  reason 
and  the  less  to  unlearned  instincts."  In  future  chapters  we 
shall  see  that  some  animals  extremely  low  in  the  scale 
apparently  display  a  certain  amount  of  reason.  No  doubt 
it  is  often  difficult  to  distinguish  between  the  power  of 
reason  and  that  of  instinct.  Thus  Dr.  Hayes,  in  his  work 
on  '  The  Open  Polar  Sea,'  repeatedly  remarks  that  his 
dogs,  instead  of  continuing  to  draw  the  sledges  in  a  com- 
pact body,  diverged  and  separated  when  they  came  to 
thin  ice,  so  that  their  weight  might  be  more  evenly  dis- 
tributed. This  was  often  the  first  warning  and  notice 
which  the  travellers  received  that  the  ice  was  becoming 
thin  and  dangerous.  Now,  did  the  dogs  act  thus  from 
the  experience  of  each  individual,  or  from  the  example  of 
the  older  and  wiser  dogs,  or  from  an  inherited  habit,  that 
is,  from  an  instinct  ?  This  instinct  might  possibly  have 
arisen  since  the  time,  long  ago,  when  dogs  were  first  em- 
ployed by  the  natives  in  drawing  their  sledges  ;  or  the 
Arctic  wolves,  the  parent-stock  of  the  Esquimaux  dog, 
may  have  acquired  this  instinct,  impelling  them  not  to 
attack  their  prey  in  a  close  pack  when  on  thin  ice.  Ques- 
tions of  this  kind  are  most  difficult  to  answer. 

So  many  facts  have  been  recorded  in  various  works 
showing  that  animals  possess  some  degree  of  reason,  that 
I  will  here  give  only  two  or  three  instances,  authenticated 
by  Rengger,  and  relating  to  American  monkeys,  which 
stand  low  in  their  order.  He  states  that  when  he  first 
gave  eggs  to  his  monkeys,  they  smashed  them  and  thus 

"  Mr.  L.  H.  Morgan's  work  on  'The  American  Beaver,'  1868,  offers 
a  good  illustration  of  this  remark.  I  cannot,  however,  avoid  thinking 
that  he  goes  too  far  in  underrating  the  power  of  Instinct. 


46  THE   DESCENT   OF  MAN.  [Pabt  I. 

lost  miich  of  their  contents  ;  afterward  they  gently  hit 
one  end  against  some  hard  body,  and  picked  off  the  bits 
of  shell  with  their  fingers.  After  cutting  themselves  only 
once  with  any  sharp  tool,  they  would  not  touch  it  again, 
or  would  handle  it  Avith  the  greatest  care.  Lumps  of 
sugar  were  often  giA^en  them  wrapped  up  in  paper;  and 
Kengger  sometimes  put  a  live  wasp  in  the  paper,  so  that 
in  hastily  unfolding  it  they  got  stung ;  after  this  had  once 
happened,  they  always  first  held  the  packet  to  their  ears 
to  detect  any  movement  within.  Any  one  who  is  not  con- 
vinced by  such  facts  as  these,  and  by  what  he  may  observe 
with  his  own  dogs,  that  animals  can  reason,  would  not  be 
couAanced  by  any  thing  that  I  could  add.  XcA'ertheless 
I  Avill  giA^e  one  case  with  respect  to  dogs,  as  it  rests  on 
tAVO  distinct  observers,  and  can  hardly  depend  on  the 
modification  of  any  instinct. 

Mr.  Colquhoun"  winged  two  wild-ducks,  which  fell  on 
the  opposite  side  of  a  stream ;  his  retriever  tried  to  bring 
over  both  at  once,  but  could  not  succeed ;  she  then,  though 
never  before  known  to  ruffle  a  feather,  deliberately  killed 
one,  brought  over  the  other,  and  returned  for  the  dead 
bird.  Colonel  Hutchinson  relates  that  tAVO  partridges 
were  shot  at  once,  one  being  killed,  the  other  wounded  ; 
the  latter  ran  away,  and  was  caught  by  the  retricA^er,  who 
on  her  return  came  across  the  dead  bird  ;  "  she  stopped, 
evidently  greatly  puzzled,  and  after  one  or  two  trials, 
finding  she  could  not  take  it  up  without  permitting  the 
escape  of  the  winged  bird,  she  considered  a  moment,  then 
deliberately  murdered  it  by  giving  it  a  severe  crunch,  and 
afterward  brought  away  both  together.  This  was  the 
only  knoAAm  instance  of  her  CA^er  having  wilfully  injured 
any  game."  Here  Ave  have  reason,  though  not  quite  per- 
fect, for  the  retriever  might  have  brought  the  wounded 

"'The  Moor  and  the  Loch,'  p.  45.     Colonel  Hutchinson  on  'Dog 
Breaking,'  1850,  p.  4C. 


Chap.  II.]  MENTAL  POWERS.  47 

bird  first  and  then  returned  for  the  dead  one,  as  in  the 
case  of  the  two  wild-ducks. 

The  muleteers  in  South-  America  say,  "  I  will  not  give 
you  the  mule  whose  step  is  easiest,  but  la  mas  racional, 
— the  one  that  reasons  best ; "  and  Humboldt  "  adds, 
"this  popular  expression,  dictated  by  long  experience, 
combats  the  system  of  animated  machines,  better  perhaps 
than  all  the  arguments  of  speculative  philosophy." 

It  has,  I  think,  now  been  shown  that  man  and  the 
higher  animals,  especially  the  Primates,  have  some  few 
instincts  in  common.  All  have  the  same  senses,  intuitions, 
and  sensations — similar  passions,  affections,  and  emotions, 
even  the  more  complex  ones  ;  they  feel  wonder  and  curi- 
osity ;  they  possess  the  same  faculties  of  imitation,  atten- 
tion, memory,  imagination,  and  reason,  though  in  very 
different  degrees.  Nevertheless  many  authors  have  in^ 
sisted  that  man  is  separated  through  his  mental  faculties 
by  an  impassable  barrier  from  all  the  lower  animals.  I 
formerly  made  a  collection  of  above  a  score  of  such  apho- 
risms, but  they  are  not  worth  giving,  as  their  wide  differ- 
ence and  number  prove  the  difficulty,  if  not  the  impossi- 
bility, of  the  attempt.  It  has  been  asserted  that  man 
alone  is  capable,  of  progressive  improvement ;  that  he 
alone  makes  use  of  tools  or  fire,  domesticates  other  ani- 
mals, possesses  property,  or  employs  language ;  that  no 
other  animal  is  self-conscious,  comprehends  itself,  has  the 
power  of  abstraction,  or  possesses  general  ideas ;  that 
man  alone  has  a  sense  of  beauty,  is  liable  to  caprice,  has 
the  feeling  of  gratitude,  mystery,  etc. ;  believes  in  God,  or 
is  endowed  with  a  conscience.  I  will  hazard  a  few  remarks 
on  the  more  important  and  interesting  of  these  points. 

Archbishop  Sumner  formerly  maintained  '^  that  man 

"  'Personal  Narrative,'  Eng.  translat.,  vol.  iii.  p.  106. 
>8  Quoted  by  Sir  C.  Lyell,  '  Antiquity  of  Man,'  p.  49'7. 


48  THE   DESCENT   OF   MAN.  [Part  I. 

alone  is  capable  of  progressive  improvement.  With  ani- 
mals, looking  first  to  the  individual,  every  one  Avho  has 
had  any  experience  in  setting  traps  knows  that  young 
animals  can  be  caught  much  more  easily  than  old  ones ; 
and  they  can  be  much  more  easily  approached  by  an 
enemy.  Even  with  respect  to  old  animals,  it  is  impossible 
to  catch  many  in  the  same  place  and  in  the  same  kind  of 
trap,  or  to  destroy  them  by  the  same  kind  of  poison  ;  yet 
it  is  improbable  that  all  should  have  partaken  of  the  poi- 
son, and  impossible  that  all  should  have  been  caught  in 
the  trap.  They  must  learn  caution  by  seeing  their  breth- 
ren caught  or  poisoned.  In  North  America,  where  the 
fur-bearing  animals  have  long  been  pursued,  they  exhibit, 
acicording  to  the  unanimous  testimony  of  all  observers,  an 
almost  incredible  amount  of  sagacity,  caution,  and  cun- 
ning; but  trapping  has  been  there  so  long  carried  on  that 
inheritance  may  have  come  into  play. 

If  we  look  to  successive  generations,  or  to  the  race, 
there  is  no  doubt  that  birds  and  other  animals  gradually 
both  acquire  and  lose  caution  in  relation  to  man  or  other 
enemies;"  and  this  caution  is  certainly  in  chief  part  an 
inherited  habit  or  instinct,  but  in  part  the  result  of  indi- 
vidual experience.  A  good  observer,  Leroy,'"'  states  that 
in  districts  where  foxes  are  much  hunted,  the  young  w^hen 
they  first  leave  their  buiTOws  ai-e  incontestably  much 
more  wary  than  the  old  ones  in  districts  where  they  are 
not  much  disturbed. 

Our  domestic  dogs  arc  descended  from  wolves  and 
jackals,"  and  though  they  may  not  have  gained  in  cun- 

"  '  Journal  of  Researches  during  the  Voyage  of  the  "  Beagle,"  '  1845, 
X).  308.     '  Origin  of  Species,'  5th  edit.  p.  260. 

^^  •  Lettres  Phil,  sur  I'lntelligence  des  Animaux,'  nouvclle  edit.  1802, 
p.  8G. 

"  See  the  evidence  on  this  head  in  chap.  i.  vol.  i.  '  On  the  Variation 
.  of  Animals  and  Plants  under  Domestication.' 


Chap.  II.]  MENTAL  POWERS.  49 

niug,  and  may  have  lost  in  wariness  and  suspicion,  yet 
they  have  progressed  in  certain  moral  qualities,  such  as  in 
affection,  trustworthiness,  temper,  and  probably  in  gen- 
eral intelligence.  The  common  rat  has  conquered  and 
beaten  several  other  species  throughout  Europe,  in  parts 
of  North  America,  New  Zealand,  and  recently  in  For- 
mosa, as  ■well  as  on  the  main-land  of  China.  Mr.  Swin- 
hoe,"  who  describes  these  latter  cases,  attributes  the  vic- 
tory of  the  common  rat  over  the  large  3£us  coninga  to 
its  superior  cunning ;  and  this  latter  quality  may  be  at- 
tributed to  the  habitual  exercise  of  all  its  faculties  in 
avoiding  extirpation  by  man,  as  well  as  to  nearly  all  the 
less  cunning  or  weak-minded  rats  having  been  successively 
destroyed  by  him.  To  maintain,  independently  of  any 
direct  evidence,  that  no  animal  during  the  course  of  ages 
has  progressed  in  intellect  or  other  mental  faculties,  is  to 
beg  the  question  of  the  evolution  of  species.  Hereafter 
we  shall  see  that,  according  to  Lartet,  existing  mammals 
belonging  to  several  orders  have  larger  brains  than  their 
ancient  tertiary  prototypes. 

It  has  often  been  said  that  no  animal  uses  any  tool ; 
but  the  chimpanzee  in  a  state  of  nature  cracks  a  native 
fruit,  somewhat  like  a  walnut,  with  a  stone.^'  Rengger"* 
easily  taught  an  American  monkey  thus  to  break  open 
hard  palm-nuts,  and  afterward  of  its  own  accord  it  used 
stones  to  open  other  kinds  of  nuts,  as  well  as  boxes.  It 
thus  also  removed  the  soft  rind  of  fruit  that  had  a  disa- 
greeable flavor.  Another  monkey  was  taught  to  open  the 
lid  of  a  large  box  with  a  stick,  and  afterward  it  used  the 
stick  as  a  lever  to  move  heavy  bodies;  and  I  have  myself 
seen  a  young  orang  put  a  stick  into  a  crevice,  slip  his 

!>»  'Proc.  Zoolog.  Soc'  1864,  p.  186. 

''  Savage  and  Wyman  in  'Boston  Journal  of  Nat.  Hist.'  vol.  iv.  1843 
-'44,  p.  383. 

'•*  'Saugethiere  von  Paraguay,'  1830,  s.  51-56. 


60  THE   DESCENT   OF   MAX.  [P.uit  I. 

hand  to  the  other  end,  and  use  it  in  the  proper  manner  as 
a  lever.  In  the  cases  just  mentioned  stones  and  sticks 
were  employed  as  implements ;  but  they  arc  likewise  used 
as  weapons.  Brehm  "  states,  on  the  authority  of  the  well- 
known  traveller  Schimper,  that  in  Abyssinia  when  the 
baboons  belonging  to  one  sj^ecies  ( C.  gelacla)  descend  in 
troops  from  the  mountains  to  plunder  the  fields,  they 
sometimes  encounter  troops  of  another  species  (  C.  hama- 
dryas),  and  then  a  fight  ensues.  The  Geladas  roll  down 
great  stones,  which  the  Ilaraadryas  try  to  avoid,  and  then 
both  species,  making  a  great  uproar,  rush  furiously 
against  each  other.  Brehm,  when  accompanying  the 
Duke  of  Coburg-Gotha,  aided  in  an  attack  with  fire-arms 
on  a  troop  of  baboons  in  the  pass  of  Mensa  in  Abyssinia. 
The  baboons  in  return  rolled  so  many  stones  down  the 
mountain,  some  as  large  as  a  man's  head,  that  the  at- 
tackers had  to  beat  a  hasty  retreat ;  and  the  pass  was 
actually  for  a  time  closed  against  the  caravan.  It  de- 
serves notice  that  these  baboons  thus  acted  in  concert. 
Mr.  Wallace  "  on  three  occasions  saw  female  orangs,  ac- 
companied by  their  young,  "  breaking  ofi"  branches  and 
the  great  spiny  fruit  of  the  Durian-tree,  with  every  ap- 
pearance of  rage;  causing  such  a  shower  of  missiles  as 
effectually  kept  us  from  approaching  too  near  the  tree." 

In  the  Zoological  Gardens  a  monkey  which  had  weak 
teeth  used  to  break  open  nuts  with  a  stone ;  and  I  was 
assured  by  the  keepers  that  this  animal,  after  using  the 
stone,  hid  it  in  the  straw,  and  would  not  let  any  other 
monkey  touch  it.  Here,  then,  we  have  the  idea  of  prop- 
erty; but  this  idea  is  common  to  every  dog  with  a  bone, 
and  to  most  or  all  birds  with  their  nests. 

The  Duke  of  Argyll "  remarks,  that  the  fashioning  of 

«  '  Thierleben,'  B.  i.  s.  19,  82. 

'^  'The  Malay  Archipelago,'  vol.  i.  1869,  p.  87. 

"  'Primeval  Man,'  1SG9,  pp.  145,  147. 


Chap.  II.]  MENTAL  POWERS.  51 

an  implement  for  a  special  purpose  is  absolutely  peculiar 
to  man ;  and  he  considers  that  this  forms  an  immeasur- 
able gulf  between  him  and  the  brutes.  It  is  no  doubt  a 
very  important  distinction,  but  there  appears  to  me  much 
truth  in  Sir  J.  Liibbock's  suggestion,'*  that  when  prime- 
val man  first  used  flint-stones  for  any  purpose,  he  would 
have  accidentally  splintered  them,  and  would  then  have 
used  the  sharp  fragments.  From  this  step  it  would  be  a 
small  one  to  intentionally  break  the  flints,  and  not  a  very 
wide  step  to  rudely  fashion  them.  This  latter  advance, 
however,  may  have  taken  long  ages,  if  we  may  judge  by 
the  immense  interval  of  time  which  elapsed  before  the  men 
of  the  neolithic  period  took  to  grinding  and  polishing 
their  stone  tools.  In  breaking  the  flints,  as  Sir  J.  Lub- 
bock likewise  remarks,  sparks  Avould  have  been  emitted, 
and  in  grinding  them  heat  would  have  been  evolved: 
"  thus  the  two  usual  methods  of  obtaining  fire  may  have 
originated."  The  nature  of  fire  would  have  been  known 
in  the  many  volcanic  regions  where  lava  occasionally 
flows  through  forests.  The  anthropomorphous  apes, 
guided  probably  by  instinct,  build  for  themselves  tempo- 
rary jilatforms  ;  but  as  many  instincts  are  largely  con- 
trolled by  reason,  the  simpler  ones,  such  as  this  of  build- 
ing a  platform,  might  readily  pass  into  a  voluntary  and 
conscious  act.  The  orang  is  known  to  cover  itself  at 
night  with  the  leaves  of  the  Pandanus  ;  and  Brehm  states 
that  one  of  his  baboons  used  to  protect  itself  from  the 
heat  of  the  sun  by  throwing  a  straw  mat  over  its  head. 
In  these  latter  habits,  we  probably  see  the  first  steps 
toward  some  of  the  simpler  arts ;  namely,  rude  architec- 
ture and  dress,  as  they  arose  among  the  early  progeni- 
tors of  man. 

Language. — This  faculty  has  justly  been   considered 
as  one  of  the  chief  distinctions  between  man  and  the  lower 

"^^  'Prehistoric  Times,'  1863,  p.  473,  etc. 


62  THE  DESCENT  OF  MAN.  [Part  I. 

animals.  But  man,  as  a  highly  competent  judge,  Arch- 
bishop Whately  remarks,  "is  not  the  only  animal  that  can 
make  use  of  language  to  express  what  is  passing  in  his 
mind,  and  can  understand,  more  or  less,  what  is  so  ex- 
pressed by  another." "  In  Paraguay  the  Cehus  azarce 
when  excited  utters  at  least  six  distinct  sounds,  which  ex- 
cite in  other  monkeys  similar  emotions/"  The  movements 
of  the  features  and  gestures  of  monkeys  are  understood 
by  us,  and  they  partly  understand  ours,  as  Rengger  and 
others  declare.  It  is  a  more  remarkable  fact  that  the  dog, 
since  being  domesticated,  has  learned  to  bark  "  in  at  least 
four  or  five  distinct  tones.  Although  barking  is  a  new 
art,  no  doubt  the  wild  species,  the  parents  of  the  dog,  ex- 
pressed their  feelings  by  cries  of  various  kinds.  "With 
the  domesticated  dog  we  have  the  bark  of  eagerness,  as 
in  the  chase  ;  that  of  anger;  the  yelping  or  howling  bark 
of  despair,  as  when  shut  up  ;  that  of  joy,  as  when  starting 
on  a  walk  with  his  master;  and  the  very  distinct  one  of 
demand  or  supplication,  as  when  wishing  for  a  door  or 
window  to  be  opened. 

Articulate  language  is,  however,  peculiar  to  man ;  but 
he  uses  in  common  with  the  lower  animals  inarticulate 
cries  to  express  his  meaning,  aided  by  gestures  and  the 
movements  of  the  muscles  of  the  face."'  This  especially 
holds  good  with  the  more  simple  and  vivid  feelings, 
which  are  but  little  connected  with  our  higher  intelli- 
gence. Our  cries  of  pain,  fear,  surprise,  anger,  together 
with   their   appropriate   actions,   and  the   murmur  of  a 

-"  Quoted  in  'Anthropological  Review,'  18G4,  p.  153. 

2"  Hengger,  ibid.  s.  45. 

3'  See  my  '  Variation  of  Animals  and  Plants  under  Domestication,' 
vol.  i  p.  27. 

3'^  S;3e  a  discussion  on  this  subject  in  Mr.  E.  B.  Tylor's  very  interest- 
ing work,  'Researches  into  the  Early  History  of  Mankind,'  1663,  chaps, 
ii.  to  iv. 


Chap.  IL]  MENTAL  POWERS.  53 

mother  to  her  beloved  child,  are  more  expressive  than  any 
words.  It  is  not  the  mere  power  of  articulation  that  dis- 
tinguishes man  from  other  animals,  for,  as  every  one 
knows,  parrots  can  talk ;  but  it  is  his  large  power  of  con- 
necting definite  sounds  with  definite  ideas ;  and  this  ob^dous- 
ly  depends  on  the  development  of  the  mental  faculties. 

As  Home  Tooke,  one  of  the  founders  of  the  noble 
science  of  philology,  observes,  language  is  an  art,  like 
brewing  or  baking ;  but  writing  would  have  been  a  much 
more  appropriate  simile.  It  certainly  is  not  a  true  in- 
stinct, as  every  language  has  to  be  learned.  It  differs, 
however,  widely  from  all  ordinary  arts,  for  man  has  an 
instinctive  tendency  to  speak,  as  we  see  in  the  babble  of 
our  young  children ;  while  no  child  has  an  instinctive 
tendency  to  brew,  bake,  or  write.  Moreover,  no  philolo- 
gist now  sujjjjoses  that  any  language  has  been  deliberately 
invented;  each  has  been  slowly  and  unconsciously  de- 
veloped by  many  steps.  The  sounds  uttered  by  birds 
offer  in  several  respects  the  nearest  analogy  to  language, 
for  all  the  members  of  the  same  species  utter  the  same  in- 
stinctive cries  expressive  of  their  emotions ;  and  all  the 
kinds  that  have  the  power  of  singing  exert  this  power  in- 
stinctively ;  but  the  actual  song,  and  even  the  call-notes, 
are  learned  from  their  parents  or  foster-parents.  These 
sounds,  as  Daines  Barrington  ^'  has  proved,  "  are  no  more 
innate  than  language  is  in  man."  The  first  attempt  to 
sing  "  may  be  compared  to  the  imperfect  endeavor  in  a 
child  to  babble."  The  young  males  continue  practising, 
or,  as  the  bird-catchers  say,  recording,  for  ten  or  eleven 
months.  Their  first  essays  show  hardly  a  rudiment  of  the 
future  song ;  but  as  they  grow  older  we  can  perceive  what 
they  are  aiming  at ;  and  at  last  they  are  said  "  to  sing 

33  Hon.  Daines  Barrington  in  'Philosoph.  Transactions,'  1773,  p.  262. 
See  also  Dureau  de  la  Malle,  in  '  Ann.  des  Sc.  Nat.'  3d  series,  Zoolog. 
torn.  X.  p.  119. 


54  THE   DESCENT   OF   MAN.  [Part  L 

their  song  round."  Nestlings  which  have  learned  the  song 
of  a  distinct  species,  as  with  the  canary-birds  educated  in 
the  Tyrol,  teach  and  transmit  their  new  song  to  their  off- 
Bpring.  The  slight  natural  differences  of  song  in  the  same 
species  inhabiting  different  districts  may  be  appositely 
compared,  as  Barrington  remarks,  "  to  provincial  dia- 
lects ; "  and  the  songs  of  allied  though  distinct  species 
may  be  compared  with  the  languages  of  distinct  races  of 
man.  I  have  given  the  foregoing  details  to  show  that  an 
instinctive  tendency  to  acquire  an  art  is  not  a  peculiarity 
confined  to  man. 

With  respect  to  the  origin  of  articulate  language, 
after  having  read  on  the  one  side  the  highly-interesting 
works  of  Mr,  Hensleigh  Wedgwood,  the  Kev.  F.  Farrar, 
and  Prof.  Schleicher,"  and  the  celebrated  lectures  of  Prof. 
Max  Mtiller  on  the  other  side,  I  cannot  doubt  that  lan- 
guage owes  its  origin  to  the  imitation  and  modification, 
aided  by  signs  and  gestures,  of  various  natural  sounds, 
the  voices  of  other  animals,  and  man's  own  instinctive 
cries.  When  we  treat  of  sexual  selection  we  shall  see 
that  primeval  man,  or  rather  some  early  progenitor  of 
man,  probably  used  his  voice  largely,  as  does  one  of  the 
gibbon-apes  at  the  present  day,  in  producing  true  musical 
cadences,  that  is  in  singing ;  we  may  conclude  from  a 
widely-spread  analogy  that  this  power  would  have  been 
especially  exerted  during  the  courtship  of  the  sexes,  serv- 
ing to  express  various  emotions,  as  love,  jealousy,  triumph, 
and  serving  as  a  challenge  to  their  rivals.  The  imitation 
by  articulate  soi;nds  of  musical  cries  might  have  given 

"  '  On  the  Origin  of  Language,' .by  II.  Wedgwood,  1860.  'Chapters 
on  Language,'  by  the  Rev.  F.  W.  Farrar,  18G5.  These  works  are  most 
interesting.  See  also  '  De  la  Phys.  ct  de  Parole,'  par  Albert  Lemoine, 
18G5,  p.  190.  The  work  on  this  subject,  by  the  late  Prof.  Aug.  Schlei- 
cher, has  been  translated  by  Dr.  Bikkers  into  English,  under  the  title  of 
'Darwinism  tested  by  the  Science  of  Language,'  18G9. 


Chap.  II.]  MENTAL   POWERS.  55- 

rise  to  words  expressive  of  various  complex  emotions.  As 
bearing  on  the  subject  of  imitation,  the  strong  tendency 
in  our  nearest  allies,  the  monkeys,  in  microcephalous 
idiots,"  and  in  the  barbarous  races  of  mankind,  to  imi- 
tate whatever  they  hear  deserves  notice.  As  monkeys 
certainly  understand  much  that  is  said  to  them  by  man, 
and  as  in  a  state  of  nature  they  utter  signal-cries  of  dan- 
ger to  their  fellows,'^  it  does  not  appear  altogether  incred- 
ible, that  some  unusually  wise  ape-like  animal  should  have 
thought  of  imitating  the  growl  of  a  beast  of  prey,  so  as 
to  indicate  to  his  fellow-monkeys  the  nature  of  the  ex- 
pected danger.  And  this  would  have  been  a  first  step  in 
the  formation  of  a  language. 

As  the  voice  was  used  more  and  more,  the  vocal  or- 
gans would  have  been  strengthened  and  perfected  through 
the  principle  of  the  inherited  effects  of  use;  and  this 
would  have  reacted  on  the  power  of  speech.  But  the 
relation  between  the  continued  use  of  language  and  the 
development  of  the  brain  has  no  doubt  been  far  more  im- 
portant. The  mental  powers  in  some  early  progenitor  of 
man  must  have  been  more  highly  developed  than  in  any 
existing  ape,  before  even  the  most  imperfect  form  of 
speech  could  have  come  into  use ;  but  we  may  confidently 
believe  that  the  continued  use  and  advancement  of  this 
power  would  have  reacted  on  the  mind  by  enabling  and 
encouraging  it  to  carry  on  long  trains  of  thought.  A 
long  and  complex  train  of  thought  can  no  more  be  carried 
on  without  the  aid  of  words,  whether  spoken  or  silent, 
than  a  long  calculation  without  the  use  of  figures  or  alge- 
bra.    It  appears,  also,  that  even  ordinary  trains  of  thought 

25  Vogt,  '  Memoire  sur  les  Microcephales,'  1867,  p.  1G9.  With  re- 
spect to  savages,  I  have  given  some  facts  in  my  '  Journal  of  Researches,' 
etc.,  1845,  p.  206. 

'®  See  clear  evidence  on  this  head  in  the  two  works  so  often  quoted, 
by  Brehm  amd  Rengger. 


56  THE   DESCENT   OF  MAN.  [Part  L 

almost  require  some  form  of  language,  for  the  dumb,  deaf, 
and  blind  girl,  Laura  Bridgman,  was  observed  to  use  her 
fingers  while  dreaming."  Nevertheless  a  long  succession 
of  vivid  and  connected  ideas  may  pass  through  the  mind 
without  the  aid  of  any  form  of  language,  as  we  may  in- 
fer from  the  prolonged  dreams  of  dogs.  We  have,  also, 
seen  that  retriever-dogs  are  able  to  reason  to  a  certain  ex- 
tent ;  and  this  they  manifestly  do  without  the  aid  of  lan- 
guage. The  intimate  connection  between  the  brain,  as  it  is 
now  developed  in  us,  and  the  faculty  of  speech,  is  Avell 
shown  by  those  curious  cases  of  brain-disease,  in  which 
speech  is  specially  affected,  as  when  the  power  to  remem- 
ber substantives  is  lost,  Avhile  other  words  can  be  correctly 
used."  There  is  no  more  improbability  in  the  effects  of 
the  continued  use  of  the  vocal  and  mental  organs  being 
inherited,  than  in  the  case  of  hand\\Titing,  which  depends 
partly  on  the  structure  of  the  hand  and  partly  on  the  dis- 
position of  the  mind ;  and  handwriting  is  certainly  in- 
herited.'' 

Why  the  organs  now  used  for  speech  should  have 
been  originally  perfected  for  this  purpose,  rather  than  any 
other  organs,  it  is  not  difficult  to  see.  Ants  have  consid- 
erable powers  of  intercommunication  by  means  of  their 
antennje,  as  shown  by  Huber,  who  devotes  a  whole  chap- 
ter to  their  language.  We  might  have  used  our  fingers 
as  eflicient  instruments,  for  a  person  with  practice  can  re- 
port to  a  deaf  man  every  word  of  a  speech  rapidly  de- 
livered at  a  public  meeting ;  but  the  loss  of  our  hands, 

*'  See  remarks  on  this  head  by  Dr.  Maudsley,  '  The  Physiology  and 
Pathology  of  Mind,'  2d  edit.  1868,  p.  199. 

*'  Many  curious  cases  have  been  recorded.  See,  for  instance,  '  In- 
quiries concerning  the  Intellectual  Powers,'  by  Dr.  Abercrombie,  1833, 
p.  150. 

*'  '  The  Variation  of  Animals  and  Plants  under  Domestication,'  vol. 
ii.  p.  6. 


Chap.  II.]  MENTAL   POWERS.  57 

while  thus  employed,  would  have  been  a  serious  incon- 
venience. As  all  the  higher  mammals  possess  vocal  or- 
gans constructed  on  the  same  general  plan  with  ours,  and 
which  are  used  as  a  means  of  communication,  it  was  ob- 
viously probable,  if  the  power  of  communication  had  to 
be  imjjroved,  that  these  same  organs  would  have  been 
still  further  developed ;  and  this  has  been  effected  by  the 
aid  of  adjoining  and  well-adapted  parts,  namely,  the 
tongue  and  lips."  The  fact  of  the  higher  apes  not  using 
their  vocal  organs  for  speech,  no  doubt  depends  on  their 
intelligence  not  having  been  sufficiently  advanced.  The 
possession  by  them  of  organs,  which  with  long-continued 
practice  might  have  been  \ised  for  speech,  although  not 
thus  used,  is  paralleled  by  the  case  of  many  birds  which 
possess  organs  fitted  for  singing,  though  they  never  sing. 
Thus,  the  nightingale  and  crow  have  vocal  organs  simi- 
larly constructed,  these  being  used  by  the  former  for  di- 
versified song,  and  by  the  latter  merely  for  croaking." 

The  formation  of  different  languages  and  of  distinct 
species,  and  the  proofs  that  both  have  been  developed 
through  a  gradual  process,  are  curiously  the  same."  But 
we  can  trace  the  origin  of  many  words  further  back  than 
in  the  case  of  species,  for  we  can  perceive  that  they  have 
arisen  from  the  imitation  of  various  sounds,  as  in  allitera- 
tive poetry.     We  find  in  distinct  languages  striking  ho- 

*"  See  some  good  remarks  to  this  effect  by  Dr.  Maudsley,  '  The 
Physiology  and  Pathology  of  Mind,'  1868,  p.  199. 

^'  Macgillivray,  'Hist,  of  British  Birds,'  vol.  ii.  1839,  p.  29.  An  ex- 
cellent observer,  Mr.  Blackwall,  remarks  that  the  magpie  learns  to  pro- 
nounce single  words,  and  even  short  sentences,  more  readily  than  almost 
any  other  British  bird ;  yet,  as  he  adds,  after  long  and  closely  investigat- 
ing its  habits,  he  has  never  known  it,  in  a  state  of  nature,  display  any 
unusual  capacity  for  imitation.     'Researches  in  Zoology,'  1884,  p.  158. 

^^  See  the  very  interesting  parallelism  between  the  development  of 
speech  and  languages,  given  by  Sir  C.  Lyell,  in  '  The  Geolog.  Evidences 
of  the  Antiquity  of  Man,'  18G3,  chap,  xxiii. 


58  THE  DESCENT   OF  MAN.  [Part  I. 

mologies  due  to  community  of  descent,  and  analogies  due 
to  a  similar  process  of  formation.  The  manner  in  which 
certain  letters  or  sounds  change  when  others  change  is 
•very  like  correlated  growth.  "We  have  in  both  cases  the 
reduplication  of  parts,  the  effects  of  long-continued  use, 
and  so  forth.  The  frequent  presence  of  rudiments,  both  in 
languages  and  in  species,  is  still  more  remarkable.  The 
letter  in  in  the  word  a;?^,  means  I ;  so  that  in  the  expres- 
sion lam^  a  superfluous  and  useless  rudiment  has  been  re- 
tained. In  the  spelling  also  of  words,  letters  often  remain 
as  the  rudiments  of  ancient  forms  of  pronunciation.  Lan- 
guages, like  organic  beings,  can  be  classed  in  groups  under 
groups ;  and  they  can  be  classed  either  naturally,  accord- 
ing to  descent,  or  artificially  by  other  characters.  Domi- 
nant languages  and  dialects  spread  widely  and  lead  to  tlie 
gradual  extinction  of  other  tongues.  A  language,  like  a 
species,  when  once  extinct,  never,  as  Sir  C.  Lyell  remarks, 
reappears.  The  same  language  never  has  two  birthplaces. 
Distinct  languages  may  be  crossed  or  blended  together," 
"We  see  variability  in  every  tongue,  and  new  words  are 
continually  cropping  up;  but  as  there  is  a  limit  to  the 
powers  of  the  memory,  single  words,  like  whole  languages, 
gradually  become  extinct.  As  Max  Miillcr  "  has  well  re- 
marked :  "  A  struggle  for  life  is  constantly  going  on  among 
the  words  and  grammatical  forms  in  each  language.  The 
better,  the  shorter,  the  easier  forms  are  constantly  gaining 
the  upper  hand,  and  they  owe  their  success  to  their  own 
inherent  virtue."  To  these  more  imjDortant  causes  of  the 
survival  of  certain  words,  mere  novelty  may,  I  think,  be 
added ;  for  there  is  in  the  mind  of  man  a  strong  love  for 
slight  changes  in  all  things.     Tlie  survival  or  preservation 

^2  Sec  remarks  to  this  effect  by  the  Rev.  F.  W.  Farrar,  in  an  interest- 
ing article,  entitled  "  Philologj^  and  Darwinism,"  in  '  Nature,'  March  24, 
1870,  p.  528. 

*^  'Nature,'  Jan.  G,  IStO,  p.  257. 


Chap.  II.]  MENTAL   POWERS.  S9 

of  certain  favored  words  in  the  struggle  for  existence  is 
natural  selection. 

The  perfectly  regular  and  wonderfully  complex  con- 
struction of  the  languages  of  many  barbarous  nations  has 
often  been  advanced  as  a  proof,  either  of  the  divine  origin 
of  these  languages,  or  of  the  high  art  and  former  civiliza- 
tion of  their  founders.  Thus  F.  von  Schlegel  writes :  "  In 
those  languages  which  appear  to  be  at  the  lowest  grade 
of  intellectual  culture,  we  frequently  observe  a  very  high 
and  elaborate  degree  of  art  in  their  grammatical  structure. 
This  is  especially  the  case  with  the  Basque  and  the  Lap- 
ponian,  and  many  of  the  American  languages."  *^  But  it 
is  assuredly  an  error  to  speak  of  any  language  as  an  art 
in  the  sense  of  its  having  been  elaborately  and  methodi- 
cally formed.  Philologists  now  admit  that  conjugations, 
declensions,  etc.,  originally  existed  as  distinct  words,  since 
joined  together ;  and  as  such  words  express  the  most  ob- 
vious relations  between  objects  and  persons,  it  is  not  sur- 
prising that  they  should  have  been  used  by  the  men  of 
most  races  during  the  earliest  ages.  With  respect  to  per- 
fection, the  following  illustration  will  best  show  how  easily 
we  may  err :  a  Crinoid  sometimes  consists  of  no  less  than 
150,000  pieces  of  shell,"  all  arranged  with  perfect  symme- 
try in  radiating  lines ;  but  a  naturalist  does  not  consider 
an  animal  of  this  kind  as  more  perfect  than  a  bilateral  one 
with  comparatively  few  parts,  and  with  none  of  these 
alike,  excepting  on  the  opposite  sides  of  the  body.  He 
justly  considers  the  differentiation  and  specialization  of 
organs  as  the  test  of  perfection.  So  with  languages,  the 
most  symmetrical  and  complex  ought  not  to  be  ranked 
above  irregular,  abbreviated,  and  bastardized  languages, 
which  have  borrowed  expressive  words  and  useful  forms 
of  construction  from  various  conquering,  or  conquered,  or 
immigrant  races. 

"5  Quoted  by  C.  S.  Wake,  'Chapters  on  Man,'  1868,  p.  101. 
*^  Buckland,  'Bridgewater  Treatise,'  p.  411. 


60  THE   DESCENT   OF   MAN.  [Part  I 

From  these  few  and  imperfect  remarks,  I  conclude  that 
the  extremely  complex  and  regular  construction  of  many 
barbarous  languages  is  no  proof  that  tliey  owe  their  origin 
to  a  special  act  of  creation/'  Nor,  as  we  have  seen,  does 
the  faculty  of  articulate  speech  in  itself  oficr  any  insuper- 
able objection  to  the  belief  that  man  has  been  developed 
from  some  lower  form. 

Self -consciousness,  Individuality,  Abstraction,  General 
•  Ideas,  etc. — ^It  would  be  useless  to  attempt  discussing  these 
high  faculties,  wliich,  according  to  several  recent  writers, 
make  the  sole  and  complete  distinction  between  man  and 
the  brutes,  for  hardly  two  authors  agree  in  their  defini- 
tions. Such  faculties  could  not  have  been  fully  developed 
in  man  until  his  mental  jjowers  had  advanced  to  a  high 
standard,  and  this  implies  the  use  of  a  perfect  language. 
No  one  supposes  that  one  of  the  lower  animals  reflects 
whence  he  comes  or  whither  he  goes — what  is  death,  or 
what  is  life,  and  so  forth.  But  can  we  feel  sure  that  an 
old  dog  with  an  excellent  memory,  and  some  power  of 
imagination,  as  shown  by  his  dreams,  never  reflects  on  his 
past  pleasures  in  the  chase  ?  and  this  would  be  a  form  of 
self-consciousness.  On  the  other  hand,  as  Buclmer*°  has 
remarked,  how  little  can  the  hard-worked  wife  of  a  de- 
graded Australian  savage,  who  uses  hardly  any  abstract 
words,  and  cannot  count  above  four,  exert  her  self-con- 
sciousness, or  reflect  on  the  nature  of  her  own  existence ! 

That  animals  retain  their  mental  individuality  is  un- 
questionable. When  my  voice  awakened  a  train  of  old 
associations  in  the  mind  of  the  above-mentioned  dog,  he 
must  have    retained   his    mental  individuality,  although 

*'  See  some  good  remarks  on  the  simplification  of  languages,  by  Sir 
J.  Lubbock,  'Origin  of  Civilization,'  1870,  p.  278. 

**  '  Conferences  sur  la  Th6orie  Darwinicnne,'  Trench  translat.,  1869,  p, 
132. 


Chap.  II.]  MENTAL  POWERS.  61 

every  atom  of  his  brain  had  probably  undergone  change 
more  than  once  during  the  interval  of  five  years.  This 
dog  might  have  brought  forwai'd  the  argument  lately  ad- 
vanced to  crush  all  evolutionists,  and  said,  "  I  abide  amid 
all  jnental  moods  and  all  material  changes.  .  .  .  The 
teaching  that  atoms  leave  their  impressions  as  legacies  to 
other  atoms  falling  into  the  places  they  have  vacated  is 
contradictory  of  the  utterance  of  consciousness,  and  is 
therefore  false  ;  but  it  is  the  teaching  necessitated  by  evo- 
lutionism, consequently  the  hypothesis  is  a  false  one."  " 

Sense  of  Beauty. — This  sense  has  been  declared  to  be 
peculiar  to  man.  But  when  we  behold  male  birds  elabo- 
rately displaying  their  plumes  and  sj)lendid  colors  before 
the  females,  while  other  birds  not  thus  decorated  make 
no  such  display,  it  is  impossible  to  doubt  that  the  females 
admire  the  beauty  of  their  male  partners.  As  women 
everywhere  deck  themselves  with  these  plumes,  the  beauty 
of  such  ornaments  cannot  be  disputed.  The  Bower-birds 
by  tastefully  ornamenting  their  playing-passages  with 
gayly-colored  objects,  as  do  certain  humming-birds  their 
nests,  ofi'er  additional  evidence  that  they  possess  a  sense 
of  beauty.  So  with  the  song  of  birds,  the  sweet  strains 
poured  forth  by  the  males  during  the  season  of  love  are 
certainly  admired  by  the  females,  of  which  fact  evidence 
will  hereafter  be  given.  If  female  birds  had  been  in- 
capable of  appreciating  the  beautiful  colors,  the  orna- 
ments, and  voices  of  their  male  partners,  all  the  labor  and 
anxiety  exhibited  by  them  in  displaying  their  charms  be- 
fore the  females  would  have  been  thrown  away  ;  and  this 
it  is  impossible  to  admit.  "Why  certain  bright  colors  and 
certain  sounds  should  excite  pleasure,  when  in  harmony, 
cannot,  I  presume,  be  explained  any  more  than  why  cer- 
tain flavors  and  scents  are  agreeable ;  but  assuredly  the 

«  The  Rev,  Dr.  J.  M'Cann,  'Anti-Darwinism,'  1869,  p.  13. 


62  THE  DESCENT   OF  MAN.  [Part  L 

same  colors  and  the  same  sounds  are  admired  by  us  and 
by  many  of  the  lower  animals. 

The  taste  for  the  beautiful,  at  least  as  far  as  female 
beauty  is  concerned,  is  not  of  a  special  nature  in  the  hu- 
man mind ;  for  it  differs  widely  in  the  different  races  of 
man,  as  will  hereafter  be  shown,  and  is  not  quite  the  same 
even  in  the  different  nations  of  the  same  race.  Judging 
from  the  hideous  ornaments  and  the  equally  hideous  music 
admired  by  most  savages,  it  might  be  urged  that  their 
aesthetic  faculty  was  not  so  highly  developed  as  in  certain 
animals,  for  instance,  in  birds.  Obviously  no  animal 
would  be  capable  of  admiring  such  scenes  as  the  heavens 
at  night,  a  beautiful  landscape,  or  refined  music  ;  but  such 
high  tastes,  depending  as  they  do  on  culture  and  complex 
associations,  are  not  enjoyed  by  barbarians  or  by  unedu- 
cated persons. 

Many  of  the  faculties,  which  have  been  of  inestimable 
service  to  man  for  his  progressive  advancement,  such  as 
the  powers  of  the  imagination,  wonder,  curiosity,  an  un- 
defined sense  of  beauty,  a  tendency  to  imitation,  and  the 
love  of  excitement  or  novelty,  could  not  fail  to  have  led 
to  the  most  capricious  changes  of  customs  and  fashions. 
I  have  alluded  to  this  point,  because  a  i-ecent  writer  "  has 
oddly  fixed  on  Caprice  "  as  one  of  the  most  remarkable 
and  typical  differences  between  savages  and  brutes."  But 
not  only  can  we  perceive  how  it  is  that  man  is  capricious, 
but  the  lower  animals  are,  as  we  shall  hereafter  sec,  capri- 
cious in  their  affections,  aversions,  and  sense  of  beauty. 
There  is  also  good  reason  to  suspect  that  they  love  nov- 
elty, for  its  own  sake. 

Belief  in  God — Heligion. — There  is  no  evidence  that 
man  was  aboriginally  endowed  with  the  ennobling  belief 
in  the  existence  of  an  Omnipotent  God.     On  the  contrary, 

'0  '  The  Spectator,'  Dec.  4,  18C9,  p.  1430. 


Chap.  II.]  MENTAL  POWERS.  63 

there  is  ampxe  evidence,  derived  not  from  hasty  travellers, 
but  from  men  who  have  long  resided  with  savages,  that 
numerous  races  have  existed  and  still  exist,  who  have  no 
idea  of  one  or  more  gods,  and  who  have  no  words  in  their 
languages  to  express  such  an  idea.^^  The  question  is  of 
course  wholly  distinct  from  that  higher  one,  whether  there 
exists  a  Creator  and  Ruler  of  the  universe ;  and  this  has 
heen  answered  in  the  affirmative  by  the  highest  intellects 
that  have  ever  lived. 

If,  however,  we  include  under  the  term  "  religion  "  the 
belief  in  imseen  or  spiritual  agencies,  the  case  is  wholly 
different ;  for  this  belief  seems  to  be  almost  universal  with 
the  less  civilized  races.  Nor  is  it  difficult  to  comprehend 
how  it  arose.  As  soon  as  the  important  faculties  of  the 
imagination,  wonder,  and  curiosity,  together  with  some 
power  of  reasoning,  had  become  partially  developed,  man 
would  naturally  have  craved  to  understand  what  was 
passing  around  him,  and  have  vaguely  speculated  on  his 
own  existence.  As  Mr.  M'Lennan  ^'  has  remarked,  "  Some 
exjDlanation  of  the  phenomena  of  life,  a  man  must  feign 
for  himself;  and  to  judge  from  the  universality  of  it,  the 
simplest  hypothesis,  and  the  first  to  occur  to  men,  seems 
to  have  been  that  natural  phenomena  are  ascribable  to 
the  presence  in  animals,  plants,  and  things,  and  in  the 
forces  of  Nature,  of  such  s^^irits  prompting  to  action  as 
men  are  conscious  they  themselves  possess."  It  is  prob- 
able, as  Mr.  Tylor  has  clearly  shown,  that  dreams  may 
have  first  given  rise  to  the  notion  of  spirits ;  for  savages 
do  not  readily  distinguish  between  subjective  and  objec- 

"  See  an  excellent  article  on  this  subject  by  the  Rev.  F.  W.  Farrar,  in 
the  'Anthropological  Review,'  Aug.  1864,  p.  ccxvii.  For  further  facts 
see  Sir  J.  Lubbock,  'Prehistoric  Tunes,'  2d  edit.  1669,  p.  564  ;  and  es- 
pecially the  chapters  on  Religion  in  his  'Origin  of  Civilization,'  1870. 

'=  The  Worship  of  Animals  and  Plants,  in  the  '  Fortnightly  Review,' 
Oct.  1,  1869,  p.  422. 


64  THE  DESCENT   OF  MAN.  [Pakt  I. 

tive  impressions.  When  a  savage  dreams,  the  figures 
"which  appear  before  him  are  believed  to  have  come  from 
a  distance  and  to  stand  over  him ;  or  "  the  soul  of  the 
dreamer  goes  out  on  its  travels,  and  comes  home  with  a 
remembrance  of  what  it  has  seen."  "  But  until  the  above- 
named  faculties  of  imagination,  curiosity,  reason,  etc.,  had 
been  fairly  well  developed  in  the  mind  of  man,  his  dreams 
would  not  have  led  him  to  believe  in  spirits,  any  more 
than  in  the  case  of  a  dog. 

The  tendency  in  savages  to  imagine  that  natural  ob- 
jects and  agencies  are  animated  by  spiritual  or  living  es- 
sences, is  perhaps  illustrated  by  a  little  fact  which  I  once 
noticed :  My  dog,  a  full-grown  and  very  sensible  animal, 
was  lying  on  the  lawn  during  a  hot  and  still  day ;  but  at 
a  little  distance  a  slight  breeze  occasionally  moved  an 
open  parasol,  which  would  have  been  wholly  disregarded 
by  the  dog,  had  any  one  stood  near  it.  As  it  was,  every 
time  that  the  parasol  slightly  moved,  the  dog  growled 
fiercely  and  barked.  lie  must,  I  think,  have  i-easoned  to 
himself  in  a  rapid  and  unconscious  manner,  that  move- 

^*  Tylor,  'Early  History  of  Mankind,'  1865,  p.  G.  See  also  the  three 
striking  chapters  on  the  Development  of  Religion,  in  Lubbock's  '  Origin 
of  Civilization,'  1870.  In  a  like  manner  Mr.  Herbert  Spencer,  in  his  in- 
genious essay  in  the  'Fortnightly  Review'  (May  1,  1870,  p.  535),  ac- 
counts for  the  earliest  forms  of  religious  belief  throughout  the  world,  by 
man  being  led  through  dreams,  shadows,  and  other  causes,  to  look  at 
himself  as  a  double  essence,  corporeal  and  spiritual.  As  the  spiritual 
being  is  supposed  to  exist  after  death  and  to  be  powerful,  it  is  propi- 
tiated by  various  gifts  and  ceremonies,  and  its  aid  invoked.  He  then 
further  shows  that  names  or  nicknames  given  from  some  animal  or  other 
object  to  the  early  progenitors  or  founders  of  a  tribe,  are  supposed  after 
a  long  interval  to  represent  the  real  progenitor  of  the  tribe  ;  and  such 
animal  or  object  is  then  naturally  believed  still  to  exist  as  a  spirit,  is  held 
sacred,  and  worshipped  as  a  god.  Nevertheless  I  cannot  but  suspect  that 
there  is  a  still  earlier  and  ruder  stage,  when  any  thing  which  manifests 
power  or  movement  is  thought  to  be  endowed  with  some  form  of  life,  and 
with  mental  faculties  analogous  to  our  own. 


Chap.  II.]  MENTAL   POWERS  65 

ment  without  any  apparent  cause  indicated  the  presence 
of  some  strange  living  agent,  and  no  stranger  had  a  right 
to  be  on  his  territory. 

The  belief  in  spiritual  agencies  would  easily  pass  into 
the  belief  in  the  existence  of  one  or  more  gods.  For 
savages  would  naturally  attribute  to  spirits  the  same  pas- 
sions, the  same  love  of  vengeance  or  simplest  form  of  jus- 
tice, and  the  same  affections  which  they  themselves  expe- 
rienced. The  Fuegians  appear  to  be  in  this  respect  in  an 
mtermediate  condition,  for  when  the  surgeon  on  board  the 
"  Beagle  "  shot  some  young  ducklings  as  specimens,  York 
Minster  declared  in  the  most  solemn  manner,  "  Oh !  Mr. 
Bynoe,  much  rain,  much  snow,  blow  much  ;  "  and  this  was 
evidently  a  retributive  punishment  for  v^asting  human 
food.  So  again  he  related  how,  when  his  brother  killed  a 
"  wild  man,"  storms  long  raged,  much  rain  and  snow  fell. 
Yet  we  covild  never  discover  that  the  Fuegians  believed 
in  what  we  should  call  a  God,  or  practised  any  religious 
rites ;  and  Jemmy  Button,  with  justifiable  pride,  stoutly 
maintained  that  there  was  no  devil  in  his  land.  This  lat- 
ter assertion  is  the  more  remarkable,  as  with  savages  the 
belief  in  bad  spirits  is  far  more  common  than  the  belief  in 
good  spirits. 

The  feeling  of  religious  devotion  is  a  highly  complex 
one,  consisting  of  love,  complete  submission  to  an  exalted 
and  mysterious  superior,  a  strong  sense  of  dependence," 
fear,  reverence,  gratitude,  hope  for  the  future,  and  perhaps 
other  elements.  No  being  could  experience  so  complex  an 
emotion  until  advanced  in  his  intellectual  and  moral  fac- 
ulties to  at  least  a  moderately  high  level.  ISTevertheless 
we  see  some  distant  approach  to  this  state  of  mind,  in  the 
deep  love  of  a  dog  for  his  master,  associated  with  com- 
plete submission,  some  fear,  and  perhaps  other  feelmgs. 

"  See  an  able  article  on  the  Psychical  Elements  of  Religion,  by  Mr. 
L.  Owen  Pike,  in  '  Anthropolog.  Review,'  April,  18*70,  p.  Isiii. 
4 


■66  THE   DESCENT   OF   MAN.  [Part  I. 

The  behavior  of  a  dog  when  returning  to  his  master  after 
an  absence,  and,  as  I  may  add,  of  a  monkey  to  his  beloved 
keej^er,  is  widely  different  from  that  toward  their  fellovrs. 
In  the  latter  case  the  transports  of  joy  appear  to  be  some- 
what less,  and  the  sense  of  equality  is  shown  in  every  ac- 
tion. Prof.  Braubach"'goes  so  far  as  to  maintain  that  a 
dog  looks  on  his  master  as  on  a  god. 

The  same  high  mental  faculties  Avhich  first  led  man  to 
believe  in  unseen  spiritual  agencies,  then  in  fetishism, 
polytheism,  and  ultimately  in  monotheism,  would  infalli- 
bly lead  him,  as  long  as  his  reasoning  powers  remained 
poorly  developed,  to  various  strange  superstitions  and  cus- 
toms. Many  of  these  are  terrible  to  think  of — such  as  the 
sacrifice  of  human  beings  to  a  blood-loving  god ;  the  trial 
of  innocent  persons  by  the  ordeal  of  poison  or  fire  ;  witch- 
craft, etc. — yet  it  is  well  occasionally  to  reflect  on  these 
superstitions,  for  they  show  us  what  an  infinite  debt  of 
gratitude  we  owe  to  the  improvement  of  our  reason,  to 
science,  and  our  acciimulated  knovrledge."  As  Sir  J. 
Lubbock  has  well  observed,  "  it  is  not  too  much  to  say 
that  the  horrible  dread  of  unknown  evil  hangs  like  a  thick 
cloud  over  savage  life,  and  embitters  every  pleasure." 
These  miserable  and  indirect  consequences  of  our  highest 
faculties  may  be  compared  with  the  incidental  and  occa- 
sional mistakes  of  the  instincts  of  the  lower  animals. 

*»  'Religion,  Moral,  etc.,  der  Darwin'schen  Art-Lehre,'  1869,  s.  63. 

"  '  Prehistoric  Times,'  2d  edit.  p.  571.  In  this  work  (at  p.  553) 
there  will  be  found  an  excellent  account  of  the  many  strange  and  capri- 
cious customs  of  savages. 


Chap.  III.l  MORAL  SEKSE  6^ 


CHAPTER  III. 

COMPARISON    OF    THE    MENTAL     POWERS     OF    MAN    AND   THE 

LOWER  ANIMALS — Continued. 

The  Moral  Sense. — Fundamental  Proposition. — The  Qualities  of  Social 
Animals. — Origin  of  Sociability. — Struggle  between  Opposed  In- 
stincts.— Man  a  Social  Animal. — The  more  enduring  Social  Instincts 
conquer  other  less  Persistent  Instincts. — The  Social  Virtues  alone  re- 
garded by  Savages. — The  Self-regarding  Virtues  acquired  at  a  Later 
Stage  of  Development. — The  Importance  of  the  Judgment  of  the 
Members  of  the  same  Community  on  Conduct. — Transmission  of 
Moral  Tendencies. — Summary. 

I  FULLY  subscribe  to  the  judgment  of  those  writers ' 
who  maintain  that,  of  all  the  differences  between  man  and 
the  lower  animals,  the  moral  sense  or  conscience  is  by  far 
the  most  important.  This  sense,  as  Mackintosh  "  remarks, 
"  has  a  rightful  supremacy  over  every  other  principle  of 
human  action  ;  "  it  is  summed  up  in  that  short  but  impe- 
rious word  ougJit,  so  full  of  high  significance.  It  is  the 
most  noble  of  all  the  attributes  of  man,  leading  him  with- 
out a  moment's  hesitation  to  risk  his  life  for  that  of  a  fel- 
low-creature ;  or  after  due  deliberation,  impelled  simply 
by  the  deep  feeling  of  right  or  duty,  to  sacrifice  it  in  some 
great  cause.  Immanuel  Kant  exclaims,  "  Duty !  Won- 
drous thought,  that  workest  neither  by  fond  insinuation, 

'  See,  for  instance,  on  this  subject,  Quatrefages,  '  Unite  de  I'Espece 
Himaine,'  1861,  p.  21,  etc. 

'•*  'Dissertation  on  Ethical  Philosophy,'  IBS'?,  p.  231,  etc. 


P8  THE   DESCENT  OF  MAN.  [Part  I. 

llattcry,  nor  by  any  threat,  but  merely  by  holding  up  thy 
naked  law  in  the  soul,  and  so  extorting  for  thyself  always 
reverence,  if  not  always  obedience ;  before  whom  all  ap- 
petites are  dumb,  however  secretly  they  rebel;  whence 
thy  original?'" 

This  great  question  has  been  discussed  by  many  writ- 
ers *  of  consummate  ability ;  and  my  sole  excuse  for  touch- 
ing on  it  is  the  impossibility  of  here  passing  it  over,  and 
because,  as  far  as  I  know,  no  one  has  approached  it  exclu- 
sively from  the  side  of  natural  history.  The  investigation 
possesses,  also,  some  independent  interest,  as  an  attempt 
to  see  how  far  the  study  of  the  lower  animals  can  throw 
light  on  one  of  the  highest  psychical  faculties  of  man. 

The  following  proposition  seems  to  me  in  a  high  degree 
probable — namely,  that  any  animal  whatever,  endowed 
with  well-marked  social  instincts,^  would  inevitably  ac- 
quire a  moral  sense  or  conscience,  as  soon  as  its  intellect- 

'  '  Metaphysics  of  Ethics,'  translated  by  J.  W.  Semple,  Edinburgh, 
183C,  p.  136. 

*  Mr.  Bain  gives  a  list  ('  Mental  and  Moral  Science,'  1808,  pp.  543-725) 
of  twenty-six  British  authors  who  have  written  on  this  subject,  and  whose 
names  are  familiar  to  every  reader ;  to  these,  Mr.  Bain's  own  name,  and 
those  of  Mr.  Lecky,  Mr.  Shadworth  Hodgson,  and  Sir  J.  Lubbock,  as  well 
as  of  others,  may  be  added. 

^  Sir  B.  Brodie,  after  observing  that  man  is  a  social  animal  ('Psycho- 
logical Inquiries,'  1854,  p.  192),  asks  the  pregnant  question,  "  Ought  not 
this  to  settle  the  disputed  question  as  to  the  existence  of  a  moral  sense  ?  " 
Similar  ideas  have  probably  occurred  to  many  persons,  as  they  did  long 
ago  to  Marcus  Aurdius.  Mr.  J.  S.  Mill  speaks,  in  his  celebrated  work, 
'  Utihtariauism '  (18G4,  p.  40),  of  the  social  feelings  as  a  "powerful  natu- 
ral sentiment,"  and  as  "  the  natural  basis  of  sentiment  for  utilitarian  mo- 
rality ; "  but,  on  the  previous  page,  he  says,  "  If,  as  is  my  own  belief,  the 
moral  feelings  are  not  innate,  but  acquired,  they  are  not  for  that  reason 
less  natural."  It  is  with  hesitation  that  I  venture  to  difter  from  so  pro- 
found a  thinker,  but  it  can  hardly  be  disputed  that  the  social  feelings  are 
instinctive  or  innate  in  the  lower  animals ;  and  why  should  they  not  bo  so 
in  man?   Mr.  Bain  (see,  for  instanc?, '  The  Emotions  and  the  Will,"  1805. 


Chap.  III.  MORAL   SENSE.  69 

ual  powers  had  become  as  well  developed,  or  nearly  as 
well  developed,  as  in  man.  For,  firstly,  the  social  in- 
stincts lead  an  animal  to  take  pleasure  in  the  society  of 
its  fellows,  to  feel  a  certain  amount  of  sympathy  with 
them,  and  to  perform  various  services  for  them.  The  ser- 
vices may  be  of  a  definite  and  evidently  instinctive  nature ; 
or  there  may  be  only  a  wish  and  readiness,  as  with  most 
of  the  higher  social  animals,  to  aid  their  fellows  in  certain 
general  ways.  But  these  feelings  and  services  are  by  no 
means  extended  to  all  the  individuals  of  the  same  species, 
only  to  those  of  the  same  association.  Secondly,  as  soon 
as  the  mental  faculties  had  become  highly  develojDed, 
images  of  ail  past  actions  and  motives  would  be  inces- 
santly passing  through  the  brain  of  each  individual ;  and 
that  feeling  of  dissatisfaction  which  invariably  results,  as 
we  shall  hereafter  see,  from  any  unsatisfied  instinct,  would 
arise,  as  often  as  it  was  perceived  that  the  enduring  and 
always  present  social  instinct  had  yielded  to  some  other 
instinct,  at  the  time  stronger,  but  neither  enduring  in  its 
nature,  nor  leaving  behind  it  a  very  vivid  impression.  It 
is  clear  that  many  instinctive  desires,  such  as  that  of  hun- 
ger, are  in  their  nature  of  shoi't  duration ;  and  after  being 
satisfied  are  not  readily  or  vividly  recalled.  Thirdly, 
after  the  power  of  language  had  been  acquired  and  the 
wishes  of  the  members  of  the  same  community  could  be 
distinctly  expressed,  the  common  opinion  how  each  mem- 
ber ought  to  act  for  the  public  good,  would  naturally  be- 
come to  a  large  extent  the  guide  to  action.  But  the  so- 
cial instincts  would  still  give  the  impulse  to  act  for  the 
good  of  the  community,  this  impulse  being  strengthened, 
directed,  and  sometimes  even  deflected,  by  public  opinion, 
the  power  of  which  rests,  as  we  shall  presently  see,  on  in- 

p.  481)  and  others  believe  that  the  moral  sense  is  acquired  by  each  indi- 
vidual during  his  lifetime.  On  the  general  theory  of  evolution  this  is  at 
least  extremely  improbable. 


10  THE  DESCENT   OF   3[AX.  [Part  I. 

Btinctive  symj)athy.  Lastly^  habit  in  the  individual  wouhl 
ultimately  i>lay  a  very  important  part  in  guiding  tlic  con- 
duct of  each  member;  for  the  social  instincts  and  im- 
pulses, like  all  other  instincts,  Avould  be  greatly  strength- 
ened by  habit,  as  Avould  obedience  to  the  wishes  and  judg- 
ment of  the  community.  These  several  subordinate  prop- 
ositions must  now  be  discussed;  and  some  of  them  at  con- 
siderable length. 

It  may  be  -well  first  to  premise  that  I  do  not  "svish  to 
maintain  that  any  strictly  social  animal^  if  its  intellectual 
faculties  Averc  to  become  as  active  and  as  highly  devel- 
oped as  in  man,  would  acquire  exactly  the  same  moral 
sense  as  ours.  In  the  same  manner  as  various  animals 
have  some  sense  of  beauty,  tliough  they  admire  widely 
different  objects,  so  they  might  have  a  sense  of  right  and 
wrong,  though  led  by  it  to  follow  widely  different  lines  of 
conduct.  If,  for  instance,  to  take  an  extreme  case,  men 
were  reared  under  j^recisely  the  same  conditions  as  hive- 
bees,  there  can  hardly  be  a  doubt  that  our  unmarried  fe- 
males would,  like  the  worker-bees,  think  it  a  sacred  duty 
to  kill  their  brothers,  and  mothers  would  strive  to  kill  their 
fertile  daughters ;  and  no  one  would  think  of  interfering. 
Nevertheless  the  bee,  or  any  other  social  animal,  would  in 
our  supposed  case  gain,  as  it  appears  to  me,  some  feeling 
of  right  and  wrong,  or  a  conscience.  For  each  individual 
would  have  an  inward  sense  of  possessing  certain  stronger 
or  more  enduring  instincts,  and  others  less  strong  or  en- 
during; so  that  there  would  often  be  a  struggle  Avhich  im- 
pulse should  be  followed ;  and  satisfaction  or  dissatisfac- 
tion Avould  be  felt,  as  past  impressions  were  compared 
during  their  incessant  passage  through  the  mind.  In  this 
case  an  inward  monitor  would  tell  the  animal  that  it 
would  have  been  better  to  have  followed  the  one  im- 
pulse rather  than  the  other.  The  one  course  ought 
to  have  been  followed :   the  one  would  have  been  rio-ht 


Chap.  III.]  MORAL   SENSE  71 

aud  the  other  wrong ;  but  to  these  terms  I  shall  have  to 
recur. 

Sociability. — Anunals  of  mauy  kinds  are  social ;  we 
find  even  distinct  species  living  together,  as  with  some 
American  monkeys,  and  with  the  united  flocks  of  rooks, 
jackdaws,  and  starlings.  Man  shows  the  same  feeling  in 
his  strong  love  for  the  dog,  which  the  dog  returns  with 
interest.  Every  one  must  have  noticed  how  miserable 
horses,  dogs,  sheep,  etc.,  are  when  separated  from  their 
companions ;  and  what  affection  at  least  the  two  former 
kinds  show  on  their  reunion.  It  is  curious  to  speculate- 
on  the  feelings  of  a  dog,  who  will  rest  peacefully  for  hours 
in  a  room  with  his  master  or  any  of  the  family,  without 
the  least  notice  being  taken  of  him ;  but,  if  left  for  a  short 
time  by  himself,  barks  or  howls  dismally.  We  will  con- 
fine our  attention  to  the  higher  social  animals,  excluding 
insects,  although  these  aid  each  other  in  many  important 
ways.  The  most  common  service  which  the  higher  ani- 
mals perform  for  each  other,  is  the  warning  each  other  of 
danger  by  means  of  the  united  senses  of  all.  Every 
sportsman  knows,  as  Dr.  Jaeger  remarks,^  how  difficult  it 
is  to  approach  animals  in  a  herd  or  troop.  Wild  horses 
and  cattle  do  not,  I  believe,  make  any  danger-signal ;  but 
the  attitude  of  any  one  who  first  discovers  an  enemy, 
warns  the  others.  Rabbits  stamp  loudly  on  the  ground 
with  their  hind-feet  as  a  signal :  sheep  and  chamois  do  the 
same,  but  with  their  fore-feet,  uttering  likewise  a  whistle. 
Many  birds  and  some  mammals  post  sentinels,  which  in 
the  case  of  seals  are  said '  generally  to  be  the  females. 
The  leader  of  a  troop  of  monkeys  acts  as  the  sentinel,  and 
utters  cries  expressive  both  of  danger  and  of  safety.*     So- 

*  '  Die  Darwin'sche  Theorie,'  s.  101. 
'  Mr.  R.  Browne  in  'Proc.  Zoolog.  Soc'     18G8,  p.  409. 
8  Brehm,  '  Thierleben,'  B.  i.  1864,  s.  52,  79.     For  the  case  of  llie  iiion- 
keys  extracting  thorns  from  each  other,  see  s.  54.     With  respect  to  the 


72  THE   DESCENT   OF   MAN.  [Pai-.t  I. 

cial  animals  pL'rlbrni  many  little  services  for  each  other: 
horses  nibble,  and  cows  lick  each  other,  on  any  spot  which 
itclics :  monkeys  search  for  each  other's  external  para- 
sites ;  and  Brehm  states  that,  after  a  troop  of  the  Cerco- 
jnthcciis  griseo-viridis  has  rushed  through  a  thorny 
brake,  each  monkey  stretches  itself  on  a  branch,  and 
anotlier  monkey  sitting  by  "  conscientiously  "  examines 
its  fur  and  extracts  every  thorn  or  burr. 

Animals  also  render  more  important  services  to  each 
other:  thus  wolves  and  some  other  beasts  of  prey  hunt 
in  packs,  and  aid  each  other  in  attacking  their  victims. 
Pelicans  fish  in  concert.  The  Ilamadryas  baboons  turn 
over  stones  to  find  insects,  etc. ;  and  when  they  come  to  a 
large  one,  as  many  as  can  stand  round,  turn  it  over  to- 
gether and  share  the  booty.  Social  animals  mutually  de- 
fend each  other.  The  males  of  some  ruminants  come  to 
the  front  when  there  is  danger  and  defend  the  herd  with 
their  horns.  I  shall  also  in  a  future  chapter  give  cases  of 
two  young  Avild-bulls  attacking  an  old  one  in  concert,  and 
of  two  stallions  together  trying  to  drive  away  a  third 
stallion  from  a  troop  of  mares.  Brehm  encountered  in 
Abyssinia  a  great  troop  of  baboons  Avhich  Avere  crossing 
a  A'alley :  some  had  already  ascended  the  opposite  moun- 
tain, and  some  were  still  in  the  valley  :  the  latter  were  at- 
tacked by  the  dogs,  but  the  old  males  immediately  hurried 
down  from  the  rocks,  and  with  mouths  widely  opened 
roared  so  fearfully,  that  the  dogs  precipitately  retreated. 
They  were  again  encouraged  to  the  attack ;  but  by  this 
time  all  the  baboons  had  reascendcd  the  heights,  except- 
ing a  young  one,  about  six  months  old,  who,  loudly  callin-^ 
for  aid,  climbed  on  a  block  of  rock  and  was  surrounded. 

Ilamadryas  turning  over  stones,  the  fact  is  given  (s.  70)  on  the  evidence 
of  Alvarez,  whose  observations  Brehm  thinlvs  quite  trustworthy.  For  the 
cases  of  the  old  male  Ijaboons  attacking  the  dogs,  see  s  19  ;  and,  with  re- 
spect to  the  eagle,  s.  50. 


Chap.  III.]  MORAL   SENSE.  73 

Now  one  of  the  largest  males,  a  true  hero,  came  down 
again  from  the  mountain,  slowly  went  to  the  young  one, 
coaxed  him,  and  triumphantly  led  him  away — the  dogs 
being  too  much  astonished  to  make  an  attack.  I  cannot 
resist  giving  another  scene  which  was  witnessed  by  this 
same  naturalist ;  an  eagle  seized  a  young  Cercopithecus, 
which,  by  clinging  to  a  branch,  was  not  at  once  carried 
off;  it  cried  loudly  for  assistance,  upon  which  the  other 
members  of  the  troop  with  much  uproar  rushed  to  the 
rescue,  surrounded  the  eagle,  and  pulled  out  so  many 
feathers,  that  he  no  longer  thought  of  his  prey,  but  only 
how  to  escajDe.  This  eagle,  as  Brehm  remarks,  assuredly 
would  never  again  attack  a  monkey  in  a  troop. 

It  is  certain  that  associated  animals  have  a  feeling  of 
love  for  each  other  which  is  not  felt  by  adult  and  non- 
social  animals.  How  far  in  most  cases  they  actually 
sympathize  with  each  other's  pains  and  pleasures  is  more 
doubtful,  especially  with  respect  to  the  latter.  Mr.  Bux- 
ton, however,  who  had  excellent  means  of  observation," 
states  that  his  macaws,  which  lived  free  in  Norfolk,  took 
"  an  extravagant  interest"  in  a  pair  with  a  nest,  and,  when- 
ever the  female  left  it,  she  was  surrounded  by  a  troop 
"  screaming  horrible  acclamations  in  her  honor."  It  is 
often  difficult  to  judge  whether  animals  have  any  feeling 
for  each  other's  sufferings.  Who  can  say  what  cows  feel, 
when  they  surround  and  stare  intently  on  a  dying  or  dead 
companion  ?  That  animals  sometimes  are  far  from  feeling 
any  sympathy  is  too  certain  ;  for  they  will  expel  a  wound- 
ed animal  from  the  herd,  or  gore  or  worry  it  to  death. 
This  is  almost  the  blackest  fact  in  natural  history,  unless 
indeed  the  explanation  Avhich  has  been  suggested  is  true, 
that  their  instinct  or  reason  leads  them  to  expel  an  in- 
jured companion,  lest  beasts  of  ])rej,  including  man, 
should  be  tempted  to  follow  the  troop.  In  this  case  their 
9  'Annals  and  Mag.  of  Xat.  Hist.'  November,  1868,  p.  382. 


74  THE   DESCENT   OF   MAX.  [Part  I. 

conduct  is  not  mucli  worse  tlian  that  of  the  Xorth  Amer- 
ican Indians  who  leave  their  feeble  comrades  to  perisl) 
on  the  plains,  or  the  Feegeans,  who,  when  their  parents 
get  old  or  fall  ill,  bury  them  alive.'" 

Many  animals,  however,  certainly  sympatliize  with 
each  other's  distress  or  danger.  This  is  tlie  case  even 
with  birds  ;  Captain  Stansbury  "  found,  on  a  salt  lake  in 
Utah,  an  old  and  completely  blind  pelican,  which  was  very 
fat,  and  must  have  been  long  and  Avell  fed  by  his  compan- 
ions. Mr.  Blyth,  as  he  informs  me,  saw  Indian  crows 
feeding  two  or  three  of  their  companions  which  were 
blind ;  and  I  have  heard  of  an  analogous  case  Avith  the 
domestic  cock.  We  may,  if  we  choose,  call  these  actions 
instinctive  ;  but  such  cases  are  much  too  rare  for  the  de- 
velopment of  any  special  instinct/^  I  have  myself  seen 
a  dog,  who  never  passed  a  great  friend  of  his,  a  cat  which 
lay  sick  in  a  basket,  without  giving  her  a  few  licks  with 
his  tongue,  the  surest  sign  of  kind  feeling  in  a  dog. 

It  must  be  called  sympathy  that  leads  a  courageous 
dog  to  fly  at  any  one  who  strikes  his  master,  as  he  cer- 
tainly will.  I  saw  a  person  pretending  to  beat  a  lady  who 
had  a  very  timid  little  dog  on  her  lap,  and  the  trial  had 
never  before  been  made.  The  little  creature  instantly 
jumped  away,  but,  after  the  pretended  beating  Avas  OA'er, 
it  was  really  pathetic  to  see  hoAV  persevcringly  he  tried  to 
lick  his  mistress's  face  and  comfort  her.  Brehm  "  states 
that  when  a  baboon  in  confinement  Avas  pursued  to  be 

"  Sir  J.  Lubbock,  '  Prehistoric  Times,'  2d  edit.  p.  446. 

"  As  quoted  by  Mr.  L.  11.  Morgan,  'The  American  Beaver,'  1868,  p. 
272.  Captain  Stansbury  also  gives  an  interesting  account  of  the  manner 
in  which  a  very  young  pelican,  carried  away  by  a  strong  stream,  was 
guided  and  encouraged  in  its  attempts  to  reach  the  shore  by  half  a  dozen 
old  birds. 

'^  As  Mr.  Bain  states,  "  effective  aid  to  a  sufferer  springs  from  sym- 
pathy proper:  "  '  Mental  and  Moral  Science,'  1868,  p.  245. 

'3  '  Thierlcbcn,'  B.  i.  s.  85. 


Chap.  III.]  MORAL   SENSE.  76 

punished,  the  others  tried  to  protect  liim.  It  must  liavc 
been  sympathy  in  the  cases  above  given  which  led  the 
baboons  and  Cercopitheci  to  defend  their  young  comrades 
from  the  dogs  and.  the  eagle.  I  will  give  only  one  other 
instance  of  sympathetic  and  heroic  conduct  in  a  little 
American  monkey.  Several  years  ago  a  keeper  at  tlic 
Zoological  Gardens,  showed  me  some  deep  and  scarcely 
healed  wounds  on  the  nape  of  his  neck,  inflicted  on  him 
while  kneeling  on  the  floor  by  a  fierce  baboon.  The  little 
American  monkey,  who  was  a  warm  friend  of  this  keeper, 
lived,  in  the  same  large  compartment,  and  was  dreadfully 
afraid  of  the  great  baboon.  Nevertheless,  as  soon  as  he 
saw  his  friend  the  keeper  in  peril,  he  rushed  to  the  rescue, 
and  by  sci'eams  and  bites  so  distracted  the  baboon  that 
the  man  was  able  to  escape,  after  running  great  risk,  as 
the  surgeon  who  attended  him  thought,  of  his  life. 

Besides  love  and  sympathy,  animals  exhibit  other  qual- 
ities which  in  us  would  be  called  moral ;  and  I  agree  witti 
Agassiz  ^*  that  dogs  possess  something  very  like  a  con- 
science. They  certainly  possess  some  poAver  of  self-com- 
mand, and  this  does  not  appear  to  be  wholly  the  result  of 
fear.  As  Braubach"  remarks,  a  dog  will  refrain  from 
stealing  food  in  the  absence  of  his  master.  Dogs  have 
long  been  accepted  as  the  very  type  of  fidelity  and  obedi- 
ence. All  animals  living  m  a  body  which  defend  each 
other  or  attack  their  enemies  in  concert,  must  be  in  some 
degree  faithful  to  each  other ;  and  those  that  follow  a 
leader  must  be  in  some  degree  obedient.  When  the  ba- 
boons in  Abyssinia '"  plunder  a  garden,  they  silently  follow 
their  leader  ;  and  if  an  imprudent  young  animal  makes  a 
noise,  he  receives  a  slap  from  the  others  to  teach  him 
silence   and   obedience ;    but  as   soon  as   they  are   sure 

»  'De  I'Espece  et  de  la  Class.'  1869,  p.  91. 
'5  'Der  Darwin'sdien  Art-Lehre,'  1869,  s.  54. 
"5  Brehm,  '  Tlucvlebeii,'  B.i.  s.  V6. 


76  THE  DESCENT   OF  MAN.  [Paut  I. 

that    there   is   no   danger,   all  show  their  joy  by  much 
clamor. 

With  respect  to  the  impulse  Avhich  leads  certain  ani- 
mals to  associate  together,  and  to  aid  each  other  in  many 
ways,  we  may  infer  that  in  most  cases  they  are  impelled 
by  the  same  sense  of  satisfaction  or  pleasure  -Nvhich  they 
experience  in  performing  other  instinctive  actions ;  or  by 
the  same  sense  of  dissatisfixction,  as  in  other  cases  of  pre- 
vented instinctive  actions.  We  see  this  in  inniimerable 
instances,  and  it  is  illustrated  in  a  striking  manner  by  the 
acquired  instincts  of  our  domesticated  animals  ;  thus  a 
young  shepherd-dog  delights  in  driving  and  running  round 
a  flock  of  sheep,  but  not  in  worrying  them ;  a  young  fox- 
hound delights  in  hunting  a  fox,  Avhile  some  other  kinds 
of  dogs,  as  I  have  witnessed,  utterly  disregard  foxes. 
What  a  strong  feeling  of  inward  satisfaction  must  impel 
a  bird,  so  full  of  activity,  to  brood  day  after  day  over  her 
eggs  !  Migratory  birds  are  miserable  if  prevented  from 
migrating,  and  perhaps  they  enjoy  starting  on  their  long 
flight.  Some  few  instincts  are  determined  solely  by  pain- 
ful feelings,  as  by  fear,  which  leads  to  self-preservation,  or 
is  specially  directed  against  certain  enemies.  No  one,  I  pre- 
sume, can  analyze  the  sensations  of  pleasure  or  pain.  In 
many  cases,  however,  it  is  probable  that  instincts  are  persist- 
ently folloAved  from  the  mere  force  of  inheritance,  without 
the  stimulus  of  either  pleasure  or  pain.  A  young  pointei*, 
when  it  first  scents  game,  apparently  cannot  help  pointing. 
A  squirrel  in  a  cage  who  pats  the  nuts  which  it  cannot  eat, 
as  if  to  bury  them  in  the  ground,  can  hardly  be  thought  to 
act  thxTS  either  from  jjleasure  or  pain.  Hence  the  common 
assumption  that  men  must  be  impelled  to  every  action  by 
experiencing  some  pleasure  or  pain  may  be  erroneous. 
Although  a  habit  may  be  blindly  and  implicitly  followed, 
independently  of  any  pleasure  or  pain  felt  at  the  mo- 
ment, yet  if  it  be  forcibly  and  abruptly  cliccked,  a  vague 


Chap.  III.]  MORAL   SENSE.  '77 

sense  of  dissatisfaction  is  generally  experienced ;  and  this 
is  especially  true  in  regard  to  persons  of  feeble  intellect. 

It  has  often  been  assumed  that  animals  were  in  the 
first  place  rendered  social,  and  that  they  feel  as  a  conse- 
quence uncomfortable  when  separated  from  each  other, 
and  comfortable  while  together ;  but  it  is  a  more  probable 
view  that  these  sensations  were  first  developed,  in  order 
that  those  animals  which  would  profit  by  living  in  so- 
ciety, should  be  induced  to  live  together,  in  the  same 
manner  as  the  sense  of  hunger  and  the  pleasure  of  eating 
were,  no  doubt,  first  acquired  in  order  to  induce  animals 
to  eat.  The  feeling  of  pleasure  from  society  is  probably 
an  extension  of  the  parental  or  filial  afiections ;  and  this 
extension  may  be  in  chief  part  attributed  to  natural  selec- 
tion, but  perhaps  in  part  to  mere  habit.  For  with  those 
animals  which  were  benefited  by  living  in  close  associa- 
tion, the  individuals  which  took  the  greatest  pleasure  in 
society  w^ould  best  escape  various  dangers ;  while  those 
that  cared  least  for  their  comrades  and  lived  solitary 
would  perish  in  greater  numbers.  With  respect  to  the 
origin  of  the  parental  and  filial  affections,  which  appar- 
ently lie  at  the  basis  of  the  social  afiections,  it  is  hopeless 
to  speculate ;  biit  we  may  infer  that  they  have  been  to  a 
large  extent  gained  through  natural  selection.  So  it  has 
almost  certainly  been  with  the  unusual  and  opposite  feel- 
ing of  hatred  between  the  nearest  relations,  as  with  the 
worker-bees  which  kill  their  brother-drones,  and  with  the 
queen-bees  which  kill  their  daughter-queens  ;  the  desire 
to  destroy,  instead  of  loving,  their  nearest  relations  hav- 
ing been  here  of  service  to  the  community. 

The  all-important  emotion  of  sympathy  is  distinct 
from  that  of  love.  A  mother  may  passionately  love  her 
sleeping  and  passive  infant,  but  she  can  then  hardly  be 
said  to  feel  sympathy  for  it.  The  love  of  a  man  for  his 
dog  is  distinct  from  sympathy,  and  so  is  that  of  a  dog 


V8  THE   DESCENT   OF   MAN.  [Pakt  I. 

for  his  master.  Adam  Smith  formerly  argued,  as  has  Mr. 
Bain  recently,  that  the  basis  of  sympathy  lies  in  our 
strong  retentivcness  of  former  states  of  pain  or  ])leasure. 
Hence,  "the  sight  of  another  person  enduring  hunger, 
cold,  fatigue,  revives  in  ns  some  recollection  of  these 
states,  which  are  jiainful  even  in  idea."  We  are  thus  im- 
pelled to  relieve  tlie  sufferings  of  another,  in  order  that 
our  own  painful  feelings  may  be  at  the  same  time  relieved. 
In  like  manner  we  arc  led  to  j^articipate  in  the  pleasures 
of  others,"  But  I  cannot  see  how  this  view  explains  the 
fact  that  sympathy  is  excited  in  an  immeasurably  stronger 
degree  by  a  beloved  than  by  an  indifferent  person.  The 
mere  sight  of  suffering,  independently  of  love,  would 
suffice  to  call  up  in  us  vivid  recollections  and  associations. 
Sympathy  may  at  first  have  originated  in  the  manner 
above  suggested ;  but  it  seems  now  to  have  become  an 
instinct,  which  is  esi^ecially  directed  toward  beloved  ob- 
jects, in  the  same  manner  as  fear  with  animals  is  especial- 
ly directed  against  certain  enemies.  As  sympathy  is  thus 
directed,  the  mutual  love  of  the  members  of  the  same 
community  will  extend  its  limits.  No  doubt  a  tiger  or 
lion  feels  symjjathy  for  the  sufferings  of  its  own  young, 
but  not  for  any  other  animal.  With  strictly  social  ani- 
mals the  feeling  will  be  more  or  less  extended  to  all  the 
associated  members,  as  we  know  to  be  the  case.  With 
mankind  selfishness,  experience,  and  imitation,  probably 
add,  as  Mr.  Bain  has  shown,  to  the  power  of  sympathy; 

"  Sec  the  first  and  striking  chapter  in  Adam  Smith's  '  Theory  of 
Moral  Sentiments.'  Also  Mr.  Bain's  '  Mental  and  Moral  Science,'  18G8,  p. 
244,  and  275-282.  Mr.  Bain  states  that  "  sympathy  is,  indirectly,  a 
source  of  pleasure  to  the  spnpathizer ; "  and  he  accounts  for  this  through 
reciprocity.  He  remarks  that  "  the  person  benefited,  or  others  in  his 
stead,  may  make  up,  by  sympathy  and  good  offices  returned,  for  all  the 
sacrifice."  But  if,  as  appears  to  be  the  case,  sympathy  is  strictly  an  in- 
stinct, its  exercise  would  give  direct  pleasure,  in  the  same  manner  as  the 
exercise,  as  before  remarked,  of  almost  every  other  instinct. 


Chap.  III.]  MORAL   SEN'SE.  79 

for  we  are  led  by  the  hope  of  receiviug  good  m  return  to 
perform  acts  of  s^nnpathetic  kindness  to  others  ;  and  there 
can  be  no  doubt  that  the  feeling  of  sympathy  is  much 
strengthened  by  habit.  In  however  complex  a  manner 
this  feeling  may  have  originated,  as  it  is  one  of  high  im- 
portance to  all  those  animals  which  aid  and  defend  each 
other,  it  will  have  been  increased,  through  natural  selec- 
tion ;  for  those  communities  which  included  the  gi'eatest 
number  of  the  most  sympathetic  members,  Avould  flourish 
best  and  rear  the  greatest  number  of  offspring. 

In  many  cases  it  is  impossible  to  decide  whether  cer- 
tain social  instincts  have  been  acquired  through  natural 
selection,  or  are  the  indirect  I'esult  of  other  instincts  and 
faculties,  such  as  sympathy,  reason,  experience,  and  a  ten- 
dency to  imitation ;  or  again,  whether  they  are  simply  the 
result  of  long-continiied  habit.  So  remarkable  an  instinct 
as  the  placing  sentinels  to  warn  the  community  of  dan- 
ger, can  hardly  have  been  the  indirect  result  of  any  other 
faculty ;  it  must  therefore  have  been  directly  acquired. 
On  the  other  hand,  the  habit  followed  by  the  males  of 
some  social  animals,  of  defending  the  community  and  of 
attacking  their  enemies  or  their  prey  in  concert,  may  per- 
haps have  originated  from  mutual  sympathy  ;  but  courage, 
and  in  most  cases  strength,  must  have  been  previously  ac- 
quired, probably  through  natural  selection. 

Of  the  various  instincts  and  habits,  some  are  much 
stronger  than  others,  that  is,  some  either  give  more  pleas- 
ure in  their  performance  and  more  distress  in  their  preven- 
tion than  others  ;  or,  which  is  probably  quite  as  important, 
they  are  more  persistently  followed  through  inheritance 
without  exciting  any  special  feeling  of  pleasure  or  pain. 
We  are  ourselves  conscious  that  some  habits  are  much 
more  difficult  to  cure  or  change  than  others.  Hence  a  strug- 
gle may  often  be  observed  in  animals  between  different  in- 
stincts, or  between  an  instinct  and  some  habitual  disposi- 


80  THE   DESCENT   OF   MAN.  [Part  I. 

tion ;  as  wlicii  a  dog  rushes  after  a  hare,  is  rebuked, 
pauses,  hesitates,  pursues  again  or  returns  ashamed  to  his 
master ;  or  as  between  the  love  of  a  female  dog  for  her 
young  puppies  and  for  her  master,  for  she  may  be  seen  to 
slink  away  to  them,  as  if  half  ashamed  of  not  accompany- 
ine:  her  master.  But  tlie  most  curious  instance  known  to 
me  of  one  instinct  conquering  another,  is  the  migratory 
instinct  conquering  the  maternal  instinct.  The  former  is 
■wonderfully  strong ;  a  confined  bird  will  at  the  proper 
season  beat  her  breast  against  the  wires  of  her  cage,  until 
it  is  bare  and  bloody.  It  causes  young  salmon  to  leap 
out  of  the  fresh  water,  where  they  could  still  continue  to 
live,  and  thus  imintcntionally  to  commit  suicide.  Every 
one  knows  how  strong  the  maternal  instinct  is,  leading 
even  timid  birds  to  face  great  danger,  though  with  hesita- 
tion and  in  opposition  to  the  instinct  of  self-preservation. 
Nevertheless  the  migratory  instinct  is  so  powerful  that 
late  in  the  autumn  swallows  and  house-martins  frequently 
desert  their  tender  young,  leaving  them  to  perish  miser- 
ably in  their  nests.^*' 

We  can  perceive  that  an  instinctive  impulse,  if  it  be 
in  any  way  more  beneficial  to  a  species  than  some  other 
or  opposed  instinct,  would  be  rendered  the  more  potent 
of  the  two  through  natural  selection ;  for  the  individuals 
which  had  it  most  strongly  developed  would  survive  in 

'*  This  fact,  the  Rev.  L.  Jenyns  states  (see  his  edition  of  '  White's 
Nat.  Hist,  of  Selborne,'  1853,  p.  204)  was  first  recorded  by  the  illus- 
trious Jenner,  in  '  Phil.  Transact.'  1824,  and  has  since  been  confirmed  by 
several  observers,  especially  by  Mr.  Blackwall.  This  latter  careful  ob- 
server examined,  late  in  the  autumn,  during  two  years,  thirty-six  nests  ; 
he  found  that  twelve  contained  young  dead  birds,  five  contained  eggs  on 
the  point  of  being  hatched,  and  three  eggs  not  nearly  hatched.  Many 
birds  not  yet  old  enough  for  a  prolonged  flight  are  likewise  deserted  and 
left  behind.  See  Blackwall,  '  Kcscarches  in  Zoology,'  1834,  pp.  108,  118. 
For  some  additional  evidence,  although  this  is  not  wanted,  see  Lcrov, 
'Ijbttres  Phil'  1802,  p.  217. 


Chap.  III.]  MORAL   SEXSE.  81- 

larger  numbers.  Whetlier  this  is  the  case  with  the  migra- 
tory in  comparison  with  the  maternal  instinct,  may  Avell 
be  doubted.  The  great  persistence  or  steady  action  of 
the  former  at  certain  seasons  of  the  year  during  the  whole 
day,  may  give  it  for  a  time  paramount  force, 

Man  a  social  animal. — Most  persons  admit  that  man 
is  a  social  being.  We  see  this  in  his  dislike  of  solitude, 
and  in  his  wish  for  society  beyond  that  of  his  own  family. 
Solitary  confinement  is  one  of  the  severest  punishments 
which  can  be  inflicted.  Some  authors  suppose  that  man 
primevally  lived  in  single  families ;  but  at  the  present 
day,  though  single  families,  or  only  two  or  three  together, 
roam  the  solitudes  of  some  savage  lands,  they  are  always, 
as  far  as  I  can  discover,  friendly  with  other  families  in- 
habiting the  same  district.  Such  families  occasionally 
meet  in  council,  and  they  unite  for  their  common  defence. 
It  is  no  argument  against  savage  man  being  a  social  ani- 
mal, that  the  tribes  inhabiting  adjacent  districts  are  al- 
most always  at  war  with  each  other ;  for  the  social  in- 
slincts  never  extend  to  all  the  individuals  of  the  same 
species.  Judging  from  the  analogy  of  tlie  greater  num- 
ber of  the  Quadrumana,  it  is  probable  that  the  early  ape- 
like progenitors  of  man  were  likewise  social;  biit  this  is 
not  of  much  imijortance  for  us.  Although  man,  as  he 
now  exists,  has  few  s^iecial  instincts,  having  lost  any 
which  his  early  progenitors  may  have  possessed,  this  is  no 
reason  why  he  should  not  have  retained  from  an  extreme- 
ly remote  period  some  degree  of  instinctive  love  and  sym- 
pathy for  his  fellows.  We  are  indeed  all  conscious  that 
we  do  possess  such  sympathetic  feelings ; "  but  our  con- 

'^  Hume  remarks  ('  An  Enquiry  Concerning  the  Principles  of  Morals,' 
edit,  of  IVSl,  p.  132),  "there  seems  a  necessity  for  confessing  that  the 
happiness  and  misery  of  others  are  not  spectacles  altogether  indifferent 
to  us,  but  that  the  view  of  the  former  .  .  .  communicates  a  secret  joy ; 


82  THE   DESCENT   OF   MAN.  [Part  I. 

sciousness  does  not  toll  us  whether  they  are  instinctive, 
having  originated  long  ago  in  the  same  manner  as  Avith 
the  lo^ver  animals,  or  whether  they  have  been  acquired  by 
each  of  us  during  our  early  years.  As  man  is  a  social 
animal,  it  is  also  probable  that  he  would  inherit  a  ten- 
dency to  be  faithful  to  his  comrades,  for  this  quality  is 
common  to  most  social  animals.  He  would  in  like  man- 
ner possess  some  capacity  for  self-command,  and  perhaps 
of  obedience  to  the  leader  of  the  community.  He  would 
from  an  inherited  tendency  still  be  v.illing  to  defend,  in 
concert  with  others,  his  fellow-men,  and  would  be  ready 
to  aid  them  in  any  way  which  did  not  too  greatly  inter- 
fere with  his  own  welfare  or  his  own  strong  desires. 

The  social  animals  which  stand  at  the  bottom  of  the 
scale  are  guided  almost  exclusively,  and  those  which  stand 
higher  in  the  scale  are  largely  guided,  in  the  aid  which 
they  give  to  the  members  of  the  same  community,  by 
special  instincts ;  but  they  are  likewise  in  part  impelled 
by  mutual  love  and  sympathy,  assisted  apparently  by 
some  amount  of  reason.  Although  man,  as  just  remarked, 
has  no  special  instincts  to  tell  him  how  to  aid  his  fellow- 
men,  he  still  has  the  impulse,  and  with  his  improved  in- 
tellectual faculties  would  naturally  be  much  guided  in  this 
respect  by  reason  and  experience.  Instinctive  sympathy 
would,  also,  cause  him  to  value  highly  the  approbation  of 
his  fellow-men ;  for,  as  JVIr.  Bain  has  clearly  shown,"  the 
love  of  2:)raise  and  the  strong  feeling  of  glory,  and  the 
still  stronger  horror  of  scorn  and  infamy,  "  are  due  to  the 
workings  of  sympathy."  Consequently  man  would  be 
greatly  influenced  by  the  wishes,  approbation,  and  blame 
of  his  fellow-men,  as  expressed  by  their  gestures  and  lan- 
<ruaG:c.     Tims  the  social  instincts,  which  must  have  been 

the  appearance  of  the  latter  .  .  .  throws  a  molanoholy  damp  over  the 
imagination." 

i'o  'Mental  and  Moral  Science,'  18G8,  p.  254. 


Chap.  III.]  MORAL   SENSE.  83 

acquired  by  man  in  a  very  rude  state,  and  probably  even 
by  his  early  ape-like  progenitors,  still  give  the  impulse  to 
many  of  his  best  actions  ;  but  his  actions  are  largely  de- 
termined by  the  expressed  wishes  and  judgment  of  his 
fellow-men,  and  unfortunately  still  oftener  by  his  own 
strong,  selfish  desires.  But  as  the  feelings  of  love  and 
sympathy  and  the  power  of  self-command  become  strength- 
ened by  habit,  and  as  the  j)Ower  of  reasoning  becomes 
clearer  so  that  man  can  appreciate  the  justice  of  the  judg- 
ments of  his  fellow-men,  he  will  feel  himself  impelled,  in- 
dependently of  any  pleasure  or  pain  felt  at  the  moment, 
to  certain  lines  of  conduct.  He  may  then  say,  I  am  the 
supreme  judge  of  my  own  conduct,  and,  in  the  words  of 
Kant,  I  will  not  in  my  own  person  violate  the  dignity  of 
humanity. 

The  more  enduring  Social  Instincts  conquer  the  less 
Persistent  Itistincts. — We  have,  however,  not  as  yet  con- 
sidered the  main  point,  on  which  the  whole  question  of 
the  moral  sense  hinges.  Why  should  a  man  feel  that  he 
ought  to  obey  one  instinctive  desire  rather  than  another  ? 
Why  does  he  bitterly  regret  if  he  has  yielded  to  the  strong 
sense  of  self-preservation,  and  has  not  risked  his  life  to  save 
that  of  a  fellow-creature ;  or  why  does  he  regret  having 
stolen  food  from  severe  hunger  ? 

It  is  evident  in  the  first  place,  that  with  mankind  the 
instinctive  impulses  have  difterent  degrees  of  strength  ;  a 
young  and  timid  mother  urged  by  the  maternal  instinct 
will,  without  a  moment's  hesitation,  run  the  greatest  dan- 
ger for  her  infant,  but  not  for  a  mere  fellow-creature. 
Many  a  man,  or  even  boy,  who  never  before  risked  his  life 
for  another,  but  in  whom  courage  and  sympathy  were  well 
developed,  has,  disregarding  the  instinct  of  self-preserva- 
tion, instantaneously  plunged  into  a  torrent  to  save  a 
drowning  fellow-creature.     In  this  case  man  is  impelled 


84  TIIK   DESCENT   OF   MAN.  [I'ap.t  I. 

by  the  same  instinctive  motive,  wliicli  caused  the  heroic 
little  American  monkey,  furmerly  described,  to  attack  the 
great  and  dreaded  baboon,  to  save  his  keeper.  Sucli  ac- 
tions as  tlie  above  appear  to  be  the  simple  result  of  the 
greater  strength  of  the  social  or  maternal  instincts  than 
of  any  other  instinct  or  motive ;  for  they  arc  performed 
too  instantaneously  for  reflection,  or  for  the  sensation  of 
pleasui'e  or  pain  ;  though  if  prevented  distress  would  be 
caiised. 

I  am  a-svarc  that  some  persons  maintain  that  actions 
performed  impulsively,  as  in  the  above  cases,  do  not  come 
xmdcr  the  dominion  of  the  moral  sense,  and  cannot  be 
called  moral.  They  confine  this  term  to  actions  done  de- 
liberately, after  a  victory  over  ojiposing  desires,  or  to 
actions  prompted  by  some  lofty  motive.  But  it  appears 
scarcely  possible  to  draw  any  clear  line  of  distinction  of 
this  kind  ;  though  the  distinction  may  be  real.  As  far  as 
exalted  motives  are  concerned,  many  instances  have  been 
recorded  of  barbarians,  destitute  of  any  feeling  of  general 
benevolence  toward  mankind,  and  not  guided  by  any  re- 
ligious motive,  who  have  deliberately  as  prisoners  sacri- 
ficed their  lives,"'  rather  than  betray  their  comrades  ;  and 
surely  their  conduct  ought  to  be  considered  as  moral.  As 
far  as  deliberation  and  the  victory  over  opposing  motives 
are  concerned,  animals  may  be  seen  doubting  between  op- 
posed instincts,  as  in  rescuing  their  offspring  or  comrades 
from  danger ;  yet  their  actions,  though  done  for  the  good 
of  others,  are  not  called  moral.  Moreover,  an  action  re- 
peatedly performed  by  us,  will  at  last  be  done  without 
deliberation  or  hesitation,  and  can  then  hardly  be  distin- 
guished from  an  instinct ;  yet  surely  no  one  will  pretend 
that  an  action  thus  done  ceases  to  be  moral.     On  the  con- 

'■"  I  have  given  one  such  case,  namely,  of  three  Patagonian  Indians 
who  preferred  being  shot,  one  after  the  other,  to  betraying  the  plans  of 
their  companions  in  war  ('Journal  of  Researches,'  1845,  p.  103). 


Chap.  III.]  MORAL   SENSE.  85 

trary,  we  all  feel  that  an  act  cannot  be  considered  as  per- 
fect, or  as  perfoi-med  in  the  most  noble  manner,  unless  it 
be  done  impulsivelj^,  without  deliberation  or  effort,  in  the 
same  manner  as  by  a  man  in  whom  the  requisite  qualities 
are  innate.  He  who  is  forced  to  overcome  his  fear  or  want 
of  sympathy  before  he  acts,  deserves,  however,  in  one  way 
higher  credit  than  the  man  whose  innate  disposition  leads 
him  to  a  good  act  without  effoi't.  As  we  cannot  distin- 
guish between  motives,  we  rank  all  actions  of  a  certain 
class  as  moral,  when  they  are  performed  by  a  moral  being. 
A  moral  being  is  one  who  is  capable  of  comparing  his  past 
and  future  actions  or  motives,  and  of  approving  or  disap- 
proving of  them.  ^Ye  have  no  reason  to  suppose  that  any 
of  the  lower  animals  have  this  capacity ;  therefore  v/hen 
a  monkey  faces  danger  to  rescue  its  comrade,  or  takes 
charge  of  an  orphan-monkey,  we  do  not  call  its  conduct 
moral.  But  in  the  case  of  man,  who  alone  can  with  cer- 
tainty be  ranked  as  a  moral  being,  actions  of  a  certain 
class  are  called  moral,  whether  performed  deliberately 
after  a  struggle  with  opposing  motive?,  or  from  the  effects 
of  slowly-gained  habit,  or  impulsively  through  instinct. 

But  to  return  to  our  more  immediate  subject ;  although 
some  instincts  are  more  powerful  than  others,  thus  leading 
to  coi'responding  actions,  yet  it  cannot  be  maintained  that 
the  social  instincts  are  ordinarily  stronger  in  man,  or  have 
become  stronger  throiigh  long-continued  habit,  than  the 
instincts,  for  instance,  of  self-preservation,  hunger,  lust, 
vengeance,  etc.  Why,  then,  does  man  regret,  even 
though  he  may  endeavor  to  banish  any  such  regret,  that 
he  has  follov/ed  the  one  natural  impulse,  rather  than  the 
otlier ;  and  why  does  he  further  feel  that  he  ought  to  re- 
gret his  conduct  ?  Man  in  this  respect  differs  profoundly 
from  the  lower  animals.  Nevertheless  we  can,  I  think, 
see  with  some  degree  of  clearness  tlic  reason  of  this  dif- 
ference. 


86  THE   DESCENT   OF   MAN.  [Pakt  I. 

Man,  from  the  aclivity  of  his  mental  faculties,  cannot 
avoid  reflection  ;  past  impressions  and  images  are  inces- 
santly passing  througli  his  mind  with  distinctness.  Now 
with  those  animals  which  live  permanently  in  a  body,  the 
social  instincts  are  ever  present  and  jicrsistcnt.  Such  ani- 
mals are  always  ready  to  utter  the  danger-signal,  to  de- 
fend the  community,  and  to  give  aid  to  their  fello\\'s  in 
accordance  Avith  their  habits ;  they  feel  at  all  times,  with- 
out the  stimidus  of  any  sj^ecial  passion  or  desire,  some  de- 
gree of  love  and  sympathy  for  them  ;  they  are  unhappy 
if  long  separated  from  them,  and  always  happy  to  be  in 
their  com2:)any.  So  it  is  with  ourselves.  A  man  who  pos- 
sessed no  trace  of  such  feelings  would  be  an  unnatural 
monster.  On  the  other  hand,  the  desire  to  satisfy  hunger, 
or  any  passion,  such  as  vengeance,  is  in  its  nature  tempo- 
rary, and  can  for  a  time  be  fully  satisfied.  Nor  is  it  easy, 
perhaps  hardly  possible,  to  call  up  M'ith  complete  vivid- 
ness the  feeling,  for  instance,  of  hunger ;  nor,  indeed,  as 
has  often  been  remarked,  of  any  suiFering.  The  instinct 
of  self-preservation  is  not  felt  except  in  the  j^rcsence  of 
danger ;  and  many  a  coward  has  thought  himself  brave 
until  he  has  met  his  enemy  face  to  face.  The  wish  for 
another  man's  property  is,  j^erhaps,  as  persistent  a  desire 
as  any  that  can  be  named  ;  but  even  in  this  case  the  satis- 
faction of  actual  possession  is  generally  a  weaker  feeling 
than  the  desire  ;  many  a  thief,  if  not  an  habitual  one,  after 
success  lias  wondered  why  he  stole  some  article. 

Thus,  as  man  cannot  prevent  old  impressions  contin- 
ually repassing  through  his  mind,  he  will  be  compelled  to 
compare  the  weaker  impressions  of,  for  instance,  past  hun- 
ger, or  of  vengeance  satisfied  or  danger  avoided  at  the 
cost  of  other  men,  with  the  instinct  of  sympathy  and  good- 
will to  his  fellows,  which  is  still  present,  and  ever  in  some 
degree  active  in  his  mind.  lie  will  then  feel  in  his  imagi- 
nation that  a  stronger  instinct  lias  3'icldcd  to  one  which 


Chap.  III.]  MORAL   SEXSE.  87 

now  seems  comparatively  wealv ;  and  then  that  sense  of 
dissatisfaction  will  inevitably  be  felt  with  which  man  is 
endowed,  like  every  other  animal,  in  order  that  his  in- 
stincts may  be  obeyed.  The  case  before  given,  of  the 
swallow,  aftbrds  an  illustration,  though  of  a  reversed  na- 
ture, of  a  temporary,  though  for  the  time  strongly  persist- 
ent, instinct  conquering  another  instinct  which  is  usually 
dominant  over  all  others.  At  the  proper  season  these 
birds  seem  all  day  long  to  be  impressed  with  the  desire 
to  migrate ;  their  habits  change ;  they  become  restless,  are 
noisy,  and  congregate  in  flocks.  While  the  mother-bird 
is  feeding  or  brooding  over  her  nestlings,  the  maternal  in- 
stinct is  i^robably  stronger  than  the  migratoiy ;  but  the 
instinct  which  is  more  persistent  gains  the  victory,  and  at 
last,  at  a  moment  when  her  young  ones  are  not  in  sight, 
she  takes  flight  and  deserts  them.  When  arrived  at  the 
end  of  her  long  journey,  and  the  migratory  instinct  ceases 
to  act,  what  an  agony  of  remorse  each  bird  would  feel,  if, 
from  being  endowed  with  great  mental  activity,  she  could 
not  prevent  the  image  continually  passing  before  her  mind 
of  her  young  ones  perishing  in  the  bleak  north  from  cold 
and  hunger ! 

At  the  moment  of  action,  man  will  no  doubt  be  apt  to 
follow  the  stronger  impulse  ;  and,  though  this  may  occa- 
sionally prompt  him  to  the  noblest  deeds,  it  will  far  more 
commonly  lead  him  to  gratify  his  own  desires  at  the  ex- 
pense of  other  men.  But  after  their  gratification,  when 
past  and  weaker  impressions  are  contrasted  with  the  ever- 
enduring  social  instincts,  retribution  will  surely  come. 
Man  will  then  feel  dissatisfied  with  hunself,  and  will  re- 
solve, with  more  or  less  force,  to  act  difierently  for  the  fu- 
ture. This  is  conscience ;  for  conscience  looks  backward 
and  judges  past  actions,  inducing  that  kind  of  dissatisfac- 
tion, which,  if  weak,  we  call  regret,  and  if  severe,  remorse. 

These  sensations  are,  no  doiibt,  different  from  those 


88  THE   DESCENT   OF  MAN.  [Paut  I. 

experienced  wheu  other  instincts  or  desires  arc  left  unsat- 
isfied ;  but  every  unsatisfied  instinct  lias  its  own  proper 
prompting  sensation,  as  v/e  recognize  with  hunger,  thirst, 
etc.  Man  thus  prompted,  will  through  long  habit  acquire 
such  perfect  self-command,  that  his  desires  and  passions 
will  at  last  instantly  yield  to  his  social  sympathies,  and 
there  will  no  longer  be  a  struggle  between  them.  The 
still  hungry,  or  the  still  revengeful  man  will  not  think  of 
stealing  food,  or  of  wreaking  his  vengeance.  It  is  possi- 
ble, or,  as  we  shall  hereafter  see,  even  jirobable,  that  the 
habit  of  self-command  may,  like  other  habits,  be  inherited. 
Thus  at  last  man  comes  to  feel,  through  acquired,  and, 
perhaps,  inherited  habit,  that  it  is  best  for  him  to  obey 
his  more  persistent  instincts.  The  imperious  word  ougld 
seems  merely  to  employ  the  consciousness  of  the  existence 
of  a  persistent  instinct,  either  innate  or  partly  acquired, 
serving  him  as  a  guide,  though  liable  to  be  disobeyed.  "We 
hardly  use  the  word  ourjht  in  a  metaphorical  sense  when 
we  say  hounds  ought  to  hunt,  pointers  to  point,  and  re- 
trievers to  retrieve  their  game.  If  they  fail  thus  to  act, 
they  fiiil  in  their  duty  and  act  wrongly. 

If  any  desire  or  instinct,  leading  to  an  action  opposed 
to  the  good  of  others,  still  appears  to  a  man,  when  recalled 
to  mind,  as  strong  as,  or  stronger  than,  his  social  instinct, 
he  will  feel  no  keen  regret  at  having  followed  it ;  but  he 
will  be  conscious  that  if  his  conduct  were  known  to  his 
fellows,  it  would  meet  with  their  disapprobation  ;  and  few 
are  so  destitute  of  sym2:)athy  as  not  to  feel  discomfort  when 
this  is  realized.  If  he  has  no  such  sympathy,  and  if  his 
desii'es  leading  to  bad  actions  are  at  the  time  strong,  and 
when  recalled  are  not  overmastered  by  the  persistent  so- 
cial instincts,  then  he  is  essentially  a  bad  man ; "  and  the 

'^^  Dr.  Prosper  Despine,  in  bis  '  Psychologic  NaturcUc,'  18G8  (torn.  i.  p. 
243  ;  torn.  ii.  p.  169),  gives  many  curious  cases  of  the  worst  criminals,  who 
apparently  have  been  entirely  destitute  of  conscience. 


Chap.  III.]  MORAL   SEXSE.  89 

sole  restraining  motive  left  is  the  fear  of  punishment,  and 
the  conviction  that  in  the  long-run  it  would  be  best  for 
his  own  selfish  interests  to  regard  the  good  of  others  rather 
than  his  own. 

It  is  obvious  that  every  one  may  with  an  easy  con- 
science gratify  his  own  desires,  if  they  do  not  interfere 
with  his  social  instincts,  that  is,  with  the  good  of  others ; 
but  in  order  to  be  quite  free  from  self-reproach,  or  at  least 
of  anxiety,  it  is  almost  necessary  for  him  to  avoid  the  dis- 
approbation, whether  reasonable  or  not,  of  his  fellow-men. 
Nor  must  he  break  through  the  fixed  habits  of  his  life,  es- 
pecially if  these  are  supported  by  reason ;  for  if  he  does, 
he  will  assuredly  feel  dissatisfaction.  He  must  likewise 
avoid  the  reprobation  of  the  one  God  or  gods,  in  whom, 
according  to  his  knowledge  or  superstition,  he  may  be- 
lieve ;  but  in  this  case  the  additional  fear  of  divine  punish- 
ment often  supervenes. 

The  strictly  Sociat  Virtues  at  first  alone  regarded. — 
The  above  view  of  the  first  origin  and  nature  of  the  moral 
sense,  which  tells  us  what  we  ought  to  do,  and  of  the  con- 
science which  reproves  us  if  we  disobey  it,  accords  well 
with  what  we  see  of  the  early  and  undeveloped  condition 
of  this  faculty  in  mankind.  The  virtues  which  must  be 
practised,  at  least  generally,  by  rude  men,  so  that  they 
may  associate  in  a  body,  are  those  which  are  still  recog- 
nized as  the  most  important.  But  they  are  practised  al- 
most exclusively  in  relation  to  the  men  of  the  same  tribe  ; 
and  their  opposites  are  not  regarded  as  crimes  in  relation 
to  the  men  of  other  tribes.  No  tribe  could  hold  together 
if  murder,  robbery,  treachery,  etc.,  Avere  common ;  conse- 
quently such  crimes  within  the  limits  of  the  same  tribe 
"  are  branded  with  everlasting  infamy ; "  ''  but  excite  no 

2*  See  an  able  article  in  the  '  lifprtl^  British  Review,'  IBS'?,  p.  395.    See 
also  Mr.  W.  Bageliot's  articles  on  the  Importance  of  Obedience  and  Cohe- 
5 


90  THE   DESCENT   OF  MAX.  [Part  I, 

such  sentiment  beyond  tliesc  limits,  A  North-American 
Indian  is  well  pleased  with  himself,  and  is  honored  by 
others,  when  he  scalps  a  man  of  another  tribe ;  and  a  Dyak 
cuts  off  the  head  of  an  unoffending  person  and  dries  it  as 
a  trophy.  The  murder  of  infants  has  prevailed  on  the 
largest  scale  throughout  the  world,"  and  has  met  with  no 
reproach ;  but  infanticide,  especially  of  females,  has  been 
thought  to  be  good  for  the  tribe,  or  at  least  not  injurious. 
Suicide  during  former  times  was  not  generally  considered 
as  a  crime,"  but  rather,  from  the  courage  displayed,  as  an 
honorable  act ;  and  it  is  still  largely  practised  by  some 
semi-civilized  nations  without  reproach,  for  the  loss  to  a 
nation  of  a  single  individual  is  not  felt ;  whatever  the  ex- 
planation may  be,  suicide,  as  I  hear  from  Sir  J.  Lubbock, 
is  rarely  practised  by  the  lowest  barbarians.  It  has  been 
recorded  that  an  Indian  Thug  conscientiously  regretted 
that  he  had  not  strangled  and  robbed  as  many  travellers 
as  did  his  father  before  him.  In  a  rude  state  of  civilization 
the  robbery  of  strangers  is,  indccd,*generally  considered  as 
honorable. 

The  great  sin  of  Slavery  has  been  almost  universal,  and 
slaves  have  often  been  treated  in  an  infamous  manner.  As 
barbarians  do  not  regard  the  opinion  of  their  women,  wives 
are  commonly  treated  like  slaves.  Most  savages  are  ut- 
terly indifferent  to  the  suffermgs  of  strangers,  or  even  de- 
light in  witnessing  them.  It  is  well  known  that  the  women 
and  children  of  the  North- American  Indians  aided  in  tor- 
turing their  enemies.    Some  savages  take  a  horrid  pleasure 

rence  to  Primitive  Man,  in  the  'Fortnightly  Eevicw,'  1SG7,  p.  529,  and 
i868,  p.  457,  etc. 

**  The  fullest  account  which  I  have  met  with  is  by  Dr.  Gerland,  in  his 
'  Ueber  das  Aussterben  der  Naturvolker,'  1868  ;  but  I  shall  have  to  recur 
to  the  subject  of  infanticide  in  a  future  chapter. 

**  See  the  very  interesting  discussion  on  Suicide  in  Lecky's  '  History 
of  European  Morals,'  vol.  i.  18G9,  p.  223. 


Chap.  III.]  MORAL   SENSE.  91 

in  cruelty  to  animals/"  and  humanity  with  them  is  an  mi- 
known  virtue.  Nevertheless,  feelings  of  sympathy  and 
kindness  are  common,  especially  during  sickness,  between 
the  members  of  the  same  tribe,  and  are  sometimes  extended 
beyond  the  limits  of  the  tribe.  Mungo  Park's  touching 
account  of  the  kindness  of  the  negro  women  of  the  inte- 
rior to  him  is  well  known.  Many  instances  could  be 
given  of  the  noble  fidelity  of  savages  toward  each  other, 
but  not  to  strangers ;  common  experience  justifies  the 
maxim  of  the  Spaniard,  "  Never,  never  trust  an  Indian." 
There  cannot  be  fidelity  without  truth ;  and  this  funda- 
mental virtue  is  not  rare  between  the  members  of  the 
same  tribe ;  thus  Mungo  Park  heard  the  negro  women 
teaching  their  young  children  to  love  the  truth.  This, 
again,  is  one  of  the  virtues  which  becomes  so  deeply  root- 
ed in  the  mind  that  it  is  sometimes  practised  by  savages, 
even  at  a  high  cost,  toward  strangers ;  but  to  lie  to  your 
enemy  has  rarely  been  thought  a  sin,  as  the  history  of 
modern  diplomacy  too  plainly  shows.  As  soon  as  a  ti'ibe 
has  a  recognized  leader,  disobedience  becomes  a  crime, 
and  even  abject  submission  is  looked  at  as  a  sacred  virtue. 
As  during  rude  times  no  man  can  be  useful  or  faithful 
to  his  tribe  without  courage,  this  quality  has  universally 
been  placed  in  the  highest  rank;  and  although  in  civilized 
countries  a  good,  yet  timid  man  may  be  far  more  useful 
to  the  community  than  a  brave  one,  we  cannot  help  in- 
stinctively honoring  the  latter  above  a  coward,  however 
benevolent.  Prudence,  on  the  other  hand,  which  does  not 
concern  the  welfare  of  others,  though  a  very  useful  virtue, 
has  never  been  highly  esteemed.  As  no  man  can  practise 
the  virtues  necessary  for  the  welfai-e  of  his  tribe  without 
self-sacrifice,  self-command,  and  the  power  of  endurance, 
these  qualities  have  been  at  all  times  highly  and  most 

"^  See,  for  instance,  Mr.  Hamilton's  account  of  the  KafiSrs,  '  Anthropo- 
logical Review,'  1870,  p.  xv. 


92  THE   DESCENT   OF  MAN.  [Part  I. 

justly  valued.  The  American  savage  voluntarily  submits 
"without  a  groan  to  the  most  horrid  tortures  to  prove  and 
strengthen  his  fortitude  and  courage ;  and  we  cannot  help 
admiring  him,  or  even  an  Indian  Fakir,  who,  from  a  fool- 
ish religious  motive,  swings  suspended  by  a  hook  buried 
in  his  flesh. 

The  other  self-regarding  virtues,  which  do  not  obvious- 
ly, though  they  may  really,  affect  the  welfare  of  the  tribe, 
have  never  been  esteemed  by  savages,  though  now  highly 
appreciated  by  civilized  nations.  The  greatest  intemper- 
ance with  savages  is  no  reproach.  Their  utter  licentious- 
ness, not  to  mention  unnatural  crimes,  is  something  as- 
tounding.^' As  soon,  however,  as  marriage,  whether  po- 
lygamous or  monogamous,  becomes  common,  jealousy  will 
lead  to  the  inculcation  of  female  virtue ;  and  this  being 
honored,  will  tend  to  spread  to  the  unmarried  females. 
How  slowly  it  spreads  to  the  male  sex  we  see  at  the  pres- 
ent day.  Chastity  eminently  requires  self-command,  there- 
fore it  has  been  honored  from  a  very  early  period  in  the 
moral  history  of  civilized  man.  As  a  consequence  of  this, 
the  senseless  practice  of  celibacy  has  been  ranked  from  a 
remote  period  as  a  virtue."*  The  hatred  of  indecency, 
which  appears  to  us  so  natural  as  to  be  thought  innate, 
and  which  is  so  valuable  an  aid  to  chastity,  is  a  modern 
virtue,  appertaining  exclusively,  as  Sir  G.  Staunton  re- 
marks,"" to  civilized  life.  This  is  shown  by  the  ancient 
religious  rites  of  various  nations,  by  the  drawings  on  the 
walls  of  Pompeii,  and  by  the  practices  of  many  savages. 

We  have  now  seen  that  actions  are  regarded  by  sav- 
ages, and  Avere  probably  so  regarded  by  primeval  man,  as 
good  or  bad,  solely  as  they  affect  in  an  obvious  manner 

2'  Mr.  M'Lennan  has  given  ('  Primitive  Marriage,'  1865,  p.  I'/C)  a  good 
collection  of  facts  on  this  head. 

*8  Lecky,  'History  of  European  Morals,'  vol.  i.  1869,  p.  109. 
"  '  Embassy  to  China,'  vol.  ii.  p.  348. 


Chap.  III.]  MORAL   SENSE.  93 

the  welfare  of  the  tribe — not  that  of  the  species,  nor  that 
of  man  as  an  individual  member  of  the  tribe.  This  con- 
clusion agrees  well  with  the  belief  that  the  so-called  moral 
sense  is  aboriginally  derived  from  the  social  instincts,  for 
both  relate  at  first  exclusively  to  the  community.  The 
chief  causes  of  the  low  morality  of  savages,  as  judged  by 
our  standard,  are,  firstly,  the  confinement  of  sympathy  to 
the  same  tribe.  Secondly,  insufiicient  powers  of  reasoning, 
so  that  the  bearing  of  many  virtues,  especially  of  the  self- 
regarding  virtues,  on  the  general  welfare  of  the  tribe  is 
not  recognized.  Savages,  for  instance,  fail  to  trace  the 
multiplied  evils  consequent  on  a  want  of  temperance, 
chastity,  etc.  And,  thirdly,  weak  power  of  self-command ; 
for  this  power  has  not  been  strengthened  through  long-con- 
tinued, perhaps  inherited,  habit,  instruction,  and  religion. 
I  have  entered  into  the  above  details  on  the  immo- 
rality of  savages,'"  because  some  authors  have  recently 
taken  a  high  view  of  their  moral  nature,  or  have  attrib- 
uted most  of  their  crimes  to  mistaken  benevolence." 
These  authors  appear  to  rest  their  conclusion  on  savages 
possessing,  as  they  undoubtedly  do  possess,  and  often  in  a 
high  degree,  those  virtues  which  are  serviceable,  or  even 
necessary,  for  the  existence  of  a  tribal  community. 

Concluding  MemarJcs. — Philosophers  of  the  derivative ''' 
school  of  morals  formerly  assumed  that  the  foundation  of 
morality  lay  in  a  form  of  Selfishness ;  but  more  recently 
in  the  "  Greatest  Happiness  principle."  According  to  the 
view  given  above,  the  moral  sense  is  fundamentally  iden- 

'<•  See  on  this  subject  copious  evidence  in  Cliap.  vii.  of  Sir  J.  Lub- 
bock, '  Origin  of  Civilization,'  1870. 

21  For  instance  Lecky,  'Hist.  European  Morals,'  vol.  i.  p.  121. 

8^  This  term  is  used  in  an  able  article  in  the  •  Westminster  Review,' 
Oct.  1869,  p.  49?.  For  the  Greatest  Happiness  principle,  see  J.  S.  Mill, 
'Utilitarianism,'  p.  17. 


94  THE   DESCENT   OF  MAN.  [Paut  I. 

tical  with  the  social  instincts ;  and  in  the  case  of  the 
lower  animals  it  would  be  absurd  to  speak  of  these  in- 
stincts as  having  been  developed  from  selfishness,  or  for 
the  happiness  of  the  community.  They  have,  however, 
certainly  been  developed  for  the  general  good  of  the  com- 
munity. The  term,  general  good,  may  be  defined  as  the 
means  by  which  the  greatest  possible  number  of  individuals 
can  be  reared  in  full  vigor  and  health,  with  all  their  facul- 
ties perfect,  under  the  conditions  to  which  they  ai-e  exposed. 
As  the  social  instincts  both  of  man  and  the  lower  animals 
have  no  doubt  been  developed  by  the  same  steps,  it  would 
be  advisable,  if  found  practicable,  to  use  the  same  defini- 
tion in  both  cases,  and  to  take,  as  the  test  of  morality,  the 
general  good  or  welfare  of  the  community,  rather  than  the 
genei'al  happiness ;  but  this  definition  would  perhaps  re- 
quire some  limitation  on  account  of  political  ethics. 

Vt^hen  a  man  risks  his  life  to  save  that  of  a  fellow- 
creature,  it  seems  more  appropriate  to  say  that  he  acts  for 
the  general  good  or  welfare,  rather  than  for  the  general 
happiness  of  mankmd.  No  doubt  the  welfare  and  the 
happiness  of  the  individual  usually  coincide ;  and  a  con- 
tented, happy  tribe  will  flourish  better  than  one  that  is 
discontented  and  unhappy.  "We  have  seen  that,  at  an 
early  period  in  the  history  of  man,  the  expressed  wishes 
of  the  community  will  have  naturally  influenced  to  a  large 
extent  the  conduct  of  each  member ;  and  as  all  wish  for 
happiness,  the  "  greatest  liappincss  jirinciple "  will  have 
become  a  most  important  secondary  guide  and  object ;  the 
social  instincts,  including  sympathy,  always  serving  as 
the  primary  impulse  and  guide.  Tints  the  reproach  of  lay- 
ing the  foundation  of  the  most  noble  part  of  our  nature  in 
the  base  principle  of  selfishness  is  removed ;  unless  indeed 
the  satisfaction  which  every  animal  feels  when  it  follows 
its  proper  instincts,  and  the  dissatisfaction  felt  when  pre- 
vented, be  called  selfish. 


Chap.  III.]  MORAL   SENSE.  95 

The  expression  of  the  wishes  and  judgment  of  the 
members  of  the  same  community,  at  first  by  oral  and 
afterward  by  written  language,  serves,  as  just  remarked, 
as  a  most  important  secondary  guide  of  conduct,  in  aid  of 
the  social  instincts,  but  sometimes  in  opposition  to  them. 
This  latter  fact  is  well  exemplified  by  the  Law  of  Honor, 
that  is  the  law  of  the  opinion  of  our  equals,  and  not  of  all 
our  countrymen.  The  breach  of  this  law,  even  when  the 
breach  is  known  to  be  strictly  accordant  with  true  moral- 
ity, has  caused  many  a  man  more  agony  than  a  real  crime. 
We  recognize  the  same  influence  in  the  burning  sense  of 
shame  which  most  of  us  have  felt  even  after  the  interval 
of  years,  when  calling  to  mind  some  accidental  breach  of  a 
trifling  though  fixed  rule  of  etiquette.  The  judgment  of 
the  community  will  generally  be  guided  by  some  rude 
experience  of  what  is  best  in  the  long-run  for  all  the 
members ;  but  this  judgment  will  not  rarely  err  from 
ignorance  and  from  weak  powers  of  reasoning.  Hence  the 
strangest  customs  and  superstitions,  in  complete  opposi- 
tion to  the  true  welfare  and  happiness  of  mankind,  have 
become  all-powerful  throughout  the  world.  We  see  this 
in  the  horror  felt  by  a  Hindoo  who  breaks  his  caste,  in  the 
shame  of  a  Mahometan  Avoman  who  exposes  her  face,  and 
in  innumerable  other  instances.  It  would  be  difficult  to 
distinguish  between  the  remorse  felt  by  a  Hindoo  who  has 
eaten  unclean  food,  fi'om  that  felt  after  committing  a 
theft ;  but  the  former  would  probably  be  the  more  severe. 

How  so  many  absurd  rules  of  conduct,  as  well  as  so 
many  absurd  religious  beliefs,  have  originated  we  do  not 
know  ;  nor  how  it  is  that  they  have  become,  in  all  quar- 
ters of  the  world,  so  deeply  impressed  on  the  mind  of 
men ;  but  it  is  worthy  of  remark  that  a  belief  constantly 
inculcated  during  the  early  years  of  life,  while  the  brain 
is  impressible,  appears  to  acquire  almost  the  nature  of  an 
instinct ;  and  the  very  essence  of  an  instinct  is  that  it  is 


96  THE   DESCENT   OF  MAX.  [Parti. 

followed  independently  of  reason.  Neitlior  can  we  say 
why  certain  admirable  virtues,  such  as  the  love  of  trutli, 
are  much  more  highly  appreciated  by  some  savage  tribes 
than  by  others ;  "  nor,  again,  why  similar  differences  pre- 
vail even  among  civilized  nations.  Knowing  how  firmly 
fixed  many  strange  customs  and  superstitions  have  be- 
come, Ave  need  feel  no  surprise  that  the  self-regarding 
virtues  should  now  appear  to  us  so  natural,  supported  as 
they  are  by  reason,  as  to  be  thought  innate,  although 
they  were  not  valued  by  man  in  his  early  condition. 

Xotwithstanding  many  soxirces  of  doubt,  man  can 
generally  and  readily  distinguish  between  the  higher  and 
lower  moral  rules.  The  higher  are  founded  on  the  social 
instincts,  and  relate  to  the  welfare  of  others.  They  are 
supported  by  the  ajiprobation  of  our  fellow-men  and  by 
reason.  The  lower  rules,  though  some  of  them  when  im- 
plying self-sacrifice  hardly  deserve  to  be  called  lower, 
relate  chiefly  to  self,  and  owe  their  origin  to  public  opinion, 
when  matured  by  experience  and  cultivated  ;  for  they  are 
not  practised  by  rude  tribes. 

As  man  advances  in  civilization,  and  small  tribes  are 
united  into  larger  communities,  the  simplest  reason  would 
tell  each  individual  that  he  ought  to  extend  his  social  in- 
stincts and  sympathies  to  all  the  members  of  the  same 
nation,  though  personally  unknown  to  him.  This  point 
being  once  reached,  there  is  only  an  artificial  barrier  to 
prevent  his  sympathies  extending  to  the  men  of  all  nations 
and  races.  If,  indeed,  such  men  are  separated  from  him 
by  great  differences  in  appearance  or  habits,  experience 
unfortunately  shows  us  how  long  it  is  before  we  look  at 
them  as  our  fellow-creatures.  Sympathy  beyond  the  con- 
iincs  of  man,  that  is,  humanity  to  the  lower  animals,  seems 

23  Good  instances  are  given  by  Mi.  Wallace  in  'Scientific  Opinion,' 
Sept.  15,  18G9;  and  morn  fully  in  his  'Contributions  to  the  Theory  of 
Natural  Selection,'  1S70,  p.  3:>3. 


Chap.  III.]  MORAL   SENSE.  97 

to  be  one  of  the  latest  moral  acquisitions.  It  is  apparently 
unfelt  by  savages,  except  toward  their  pets.  How  little 
the  old  Romans  knew  of  it  is  shown  by  their  abhorrent 
gladiatorial  exhibitions.  The  very  idea  of  humanity,  as 
far  as  I  could  observe,  was  new  to  most  of  the  Gauchos  of 
the  Pampas.  This  virtue,  one  of  the  noblest  with  which 
man  is  endowed,  seems  to  arise  incidentally  from  our  sym- 
pathies becoming  more  tender  and  more  widely  diffused, 
until  they  are  extended  to  all  sentient  beings.  As  soon  as 
this  virtue  is  honored  and  practised  by  some  few  men,  it 
spreads  through  instruction  and  example  to  the  young, 
and  eventually  through  public  opinion. 

The  highest  stage  in  moral  culture  at  which  we  can 
arrive,  is  when  we  recognize  that  we  ought  to  control  our 
thoughts,  and  "  not  even  in  inmost  thought  to  think  again 
the  sins  that  made  the  past  so  pleasant  to  us."  ^*  What- 
ever makes  any  bad  action  familiar  to  the  mind,  renders 
its  performance  by  so  much  the  easier.  As  Marcus  Aure- 
lius  long  ago  said,  "  Such  as  are  thy  habitual  thoughts, 
such  also  will  be  the  character  of  thy  mind ;  for  the  soul 
is  dyed  by  the  thoughts."  " 

Our  great  philosopher,  Herbert  Spencer,  has  recently 
explained  his  views  on  the  moral  sense.  He  says :  "  "  I 
believe  that  the  experiences  of  utility  organized  and  con- 
solidated through  all  past  generations  of  the  human  race, 
have  been  producing  corresponding  modifications,  which, 
by  continued  transmission  and  accumulation,  have  become 
in  us  certain  faculties  of  moral  intviition — certain  emotions 
responding  to  right  and  wrong  conduct,  which  have  no 
apparent  basis  in  the  individual  experiences  of  utility." 

24  Tennyson,  '  Idylls  of  the  King,'  p.  244. 

25  '  The  Thoughts  of  the  Emperor  M.  Aurelius  Antonmus,'  Eng.  trans- 
lation, 2d  edit.,  1869,  p.  112.     Marcus  Aurelius  was  born  a.  d.  121. 

25  Letter  to  Mr.  Mill  in  Bain's  '  Mental  and  Moral  Science,'  1S68,  p 
722. 


98  THE   DESCENT   OF  MAN.  [Part  I. 

There  is  not  tlie  least  inherent  improbability,  as  it  seems 
to  me,  in  virtuous  tendencies  being  more  or  less  strongly- 
inherited  ;  for,  not  to  mention  tlie  various  dispositions  and 
habits  transmitted  by  many  of  our  domestic  animals,  I 
have  heard  of  cases  in  wliich  a  desire  to  steal  and  a  ten- 
dency to  lie  appeared  to  run  in  families  of  the  upper 
ranks ;  and  as  stealing  is  so  rare  a  crime  in  the  wealthy 
classes,  we  can  hardly  account  by  accidental  coincidence 
for  the  tendency  occurring  in  two  or  three  members  of  the 
same  family.  If  bad  tendencies  are  transmitted,  it  is 
probable  that  good  ones  are  likewise  transmitted.  Ex- 
cepting through  the  principle  of  the  transmission  of  moral 
tendencies,  we  cannot  understand  the  differences  believed 
to  exist  in  this  respect  between  the  various  races  of  man- 
kind. We  have,  however,  as  yet,  hardly  sufficient  evi- 
dence on  this  head. 

Even  the  partial  transmission  of  virtuous  tendencies 
would  .be  an  immense  assistance  to  the  primary  impulse 
derived  directly  from  the  social  instincts,  and  indirectly 
from  the  approbation  of  our  fellow-men.  Admitting  for 
the  moment  tliat  virtuous  tendencies  are  inherited,  it  ap- 
pears probable,  at  least  in  such  cases  as  chastity,  temper- 
ance, humanity  to  animals,  etc.,  that  they  become  jfirst  im- 
pressed on  the  mental  organization  througli  habit,  instruc- 
tion, and  example,  continued  during  several  generations 
in  the  same  family,  and  in  a  quite  subordinate  degree,  or 
not  at  all,  by  the  individuals  possessing  such  virtues, 
having  succeeded  best  in  the  struggle  for  life.  My  chief 
source  of  doubt  with  respect  to  any  such  inheritance,  is 
that  senseless  customs,  superstitions,  and  tastes,  such  as 
the  horror  ©f  a  Hindoo  for  unclean  food,  ought  on  the 
same  principle  to  be  transmitted.  Although  tliis  in  itself 
is  perhaps  not  less  probable  than  that  animals  should 
acquire  inherited  tastes  for  certain  kinds  of  food  or  fear  ol 
certain  foes,  I  have  not  met  with  any  evidence  in  support 


Chap.  III.]  MORAL   SENSE.  99 

of  the  transmission  of  superstitious  customs  or  senseless 
habits. 

Finally,  the  social  instincts  which  no  doubt  were  ac- 
quired by  man,  as  by  the  lower  animals,  for  the  good  of 
the  community,  will  from  the  first  have  given  to  him 
some  wish  to  aid  his  fellows,  and  some  feeling  of  sym- 
pathy. Such  impulses  will  have  served  him  at  a  very 
early  period  as  a  rude  rule  of  right  and  wrong.  But  as 
man  gradually  advanced  in  intellectual  power  and  was 
enabled  to  trace  the  more  remote  consequences  of  his  ac- 
tions ;  as  he  acquired  sufficient  knowledge  to  reject  bane- 
ful customs  and  superstitions ;  as  he  regarded  more  and 
more  not  only  the  welfare  but  the  hapi^iness  of  his  fellow- 
men;  as  from  habit,  following  on  beneficial  experience, 
instruction,  and  example,  his  sympathies  became  more 
tender  and  widely  diifused,  so  as  to  extend  to  the  men 
of  all  races,  to  the  imbecile,  the  maimed,  and  other  use- 
less members  of  society,  and  finally  to  the  lower  ani- 
mals— so  would  the  standard  of  his  morality  rise  higher 
and  higher.  And  it  is  admitted  by  moralists  of  the  de- 
rivative school  and  by  some  intuitionists,  that  the  stand- 
ard of  morality  has  risen  since  an  early  jDcriod  in  the  his- 
tory of  man." 

As  a  struggle  may  sometimes  be  seen  going  on  between 
the  various  instincts  of  the  lower  animals,  it  is  not  sur- 
pi'ising  that  there  should  be  a  struggle  in  man  between 
his  social  instincts,  with  their  derived  virtues,  and  his 
lower,  though,  at  the  moment,  stronger  impulses  or  desires. 
This,  as  Mr.  Galton'^  has  remarked,  is  all  the  less  sur- 

"  A  writer  in  the  '  North  British  Review  '  (July,  1869,  p.  531),  well 
capable  of  forming  a  sound  judgment,  expresses  himself  strongly  to  this 
effect.  Mr.  Lecky  ('  Hist,  of  Morals,'  vol.  i.  p.  143)  seems  to  a  certain 
extent  to  coincide. 

3^  See  his  remaikable  work  on  'Hereditary  Genius,'   1SG9,  p.  349, 


100  THE  DESCENT  OF  MAN.  [Paht  I. 

prising,  as  man  has  emerged  from  a  state  of  barbarism 
within  a  comparatively  recent  period.  After  having 
yielded  to  some  temptation,  "wc  feel  a  sense  of  dissatisfac- 
tion, analogous  to  that  felt  from  other  unsatisfied  instincts, 
called  in  this  case  conscience  ;  for  we  cannot  prevent  past 
images  and  imjiressions  continually  passing  through  our 
minds,  and  these  in  their  weakened  state  we  compare  with 
the  ever-present  social  instincts,  or  with  habits  gained  in 
early  youth  and  strengthened  during  our  whole  lives,  per- 
haps inherited,  so  that  they  are  at  last  rendered  almost  as 
strong  as  instincts.  Looking  to  future  generations,  there 
is  no  cause  to  fear  that  the  social  instincts  will  grow 
weaker,  and  Ave  may  expect  that  virtuous  habits  will  grow 
stronger,  becoming  pcrhajDS  fixed  by  inheritance.  In  this 
case  the  struggle  between  our  higher  and  lower  impulses 
will  be  less  severe,  and  virtue  will  be  triumphant. 

Summary  of  the  last  two  Chapters. — There  can  be  no 
doubt  that  the  difference  between  the  mind  of  the  lowest 
man  and  that  of  the  highest  animal  is  immense.  An  an- 
thropomorphous ape,  if  he  could  take  a  dispassionate  view 
of  his  own  case,  would  admit  that  though  he  could  form 
an  artful  plan  to  plunder  a  garden — though  he  could  use 
stones  for  fighting  or  for  breaking  open  nuts,  yet  that  the 
thought  of  fashioning  a  stone  into  a  tool  was  quite  beyond 
his  scope.  Still  less,  as  he  would  admit,  could  he  folloAV 
out  a  train  of  metaphysical  reasoning,  or  solve  a  mathe- 
matical problem,  or  reflect  on  God,  or  admire  a  grand 
natural  scene.  Some  apes,  however,  would  probably  de- 
clare that  they  could  and  did  admire  the  beauty  of  the  col- 
ored skin  and  fur  of  their  partners  in  marriage.  They 
would  admit,  that  though  they  couM  make  other  apes 
understand  by  cries  some  of  tludr  perceptions  and  simpler 

The  Duke  of  Argyll  (' Primeval  Ma;i,'  18G0,  p.  188)  has  sonic  good  re- 
marks  on  the  contest  in  mau'ii  nature  between  right  and  wrong. 


Chap.  III.]  MORAL   SENSE.  101 

wants,  the  notion  of  expressing  definite  ideas  by  definite 
sounds  had  never  crossed  their  minds.  They  might  insist 
that  they  were  ready  to  aid  their  fellow-apes  of  the  same 
troop  in  many  ways,  to  risk  their  lives  for  them,  and  to 
take  charge  of  their  orphans ;  but  they  would  be  forced  to 
acknowledge  that  disinterested  love  for  all  living  creatures, 
the  most  noble  attribute  of  man,  was  quite  beyond  their 
comprehension. 

N  e vertheless  the  difference  in  mind  between  man  and 
the  higher  animals,  great  as  it  is,  is  certainly  one  of  degree 
and  not  of  kind.  We  have  seen  that  the  senses  and  intui- 
tions, the  various  emotions  and  faculties,  such  as  love, 
memory,  attention,  curiosity,  imitation,  reason,  etc.,  of 
which  man  boasts,  may  be  found  in  an  incipient,  or  even 
sometimes  in  a  well-developed  condition,  in  the  lower  ani- 
mals. They  are  also  capable  of  some  inherited  improve- 
ment, as  we  see  in  the  domestic  dog  compared  with  the 
wolf  or  jackal.  If  it  be  maintained  that  cei'tain  powers, 
such  as  self-consciousness,  abstraction,  etc.,  are  peculiar  to 
man,  it  may  well  be  that  these  are  the  incidental  results 
of  other  highly-advanced  intellectual  faculties  ;  and  these 
again  are  mainly  the  result  of  the  continued  use  of  a 
highly-developed  language.  At  what  age  does  the  new- 
born infant  possess  the  power  of  abstraction,  or  become 
self-conscious  and  reflect  on  its  own  existence  ?  We  can- 
not answer  ;  nor  can  we  answer  in  regard  to  the  ascending 
organic  scale.  The  half-art  and  half-instinct  of  language 
still  bears  the  stamp  of  its  gradual  evolution.  The  en- 
nobling belief  in  God  is  not  vmiversal  with  man  ;  and  the 
belief  in  active  spiritual  agencies  naturally  follows  from 
his  other  mental  powers.  The  moral  sense  perhaps  affords 
the  best  and  highest  distinction  between  man  and  the 
lower  animals  ;  but  I  need  not  say  any  thing  on  this  head, 
as  I  have  so  lately  endeavored  to  show  that  the  social 
instincts — the   prime   pi'inciple   of    man's    moral   consti- 


102  THE   DESCENT   OF  MAN.  [Part  I. 

tution '"  — witli  the  aid  of  active  intellectual  powers  and 
the  cftccts  of  liabit,  naturally  lead  to  the  golden  rule,  "As 
ye  would  that  men  should  do  to  you,  do  ye  to  them  like- 
wise ; "  and  this  lies  at  the  foundation  of  morality. 

In  a  future  chapter  I  shall  make  some  few  remarks  on 
the  probable  steps  and  means  by  which  the  several  mental 
and  moral  faculties  of  man  have  been  gradually  evolved. 
That  this  at  least  is  possible  ought  not  to  be  denied,  when 
we  daily  see  their  development  in  every  infant ;  and  when 
we  may  trace  a  perfect  gradation  from  the  mind  of  an 
utter  idiot,  lower  than  that  of  the  lowest  animal,  to  the 
mind  of  a  Newton. 

2'  'The  Thoughts  of  Marcus  Aurclius,'  etc.,  p.  139. 


Chap.  IV.]  MANNER   OF  DEVELOPMENT.  103 


CHAPTER    IV. 

ON   THE    MANNER    OF     DEVELOPMENT    OF    MAN    FROM    SOME 
LOWER    FORM. 

Variability  of  Body  and  Mind  in  Man. — Inlieritancc— Causes  of  Varia- 
bility.— Laws  of  Variation  the  same  in  Man  as  in  the  Lower  Animals. 
— Direct  Action  of  the  Conditions  of  Life. — Effects  of  the  Increased 
Use  and  Disuse  of  Parts. — Arrested  Development. — Eeversion.- — Cor- 
related Variation. — Eate  of  Increase. — Checks  to  Increase. — Natural 
Selection. — Man  the  most  Dominant  Animal  in  the  World. — Impor- 
tance of  his  Corporeal  Structure. — The  Causes  which  have  led  to  his 
becoming  erect. — Consequent  Changes  of  Structure. — Decrease  in 
Size  of  the  Canine  Teeth. — Increased  Size  and  Altered  Shape  of  the 
Skull. — ^Nakedness. — Absence  of  a  Tail. — Defenceless  Condition  of 
Man. 

We  have  seen  in  the  first  chapter  that  the  homological 
structure  of  man,  his  embryological  development  and  the 
rudiments  which  he  still  retains,  all  declare  in  the  plainest 
manner  that  he  is  descended  from  some  lower  form.  The 
possession  of  exalted  mental  powers  is  no  insuperable  ob- 
jection to  this  conclusion.  In  order  that  an  ape-like  crea- 
ture should  have  been  transformed  into  man,  it  is  neces- 
sary that  this  early  form,  as  well  as  many  successive  links, 
should  all  have  varied  in  mind  and  body.  It  is  impossible 
to  obtain  direct  evidence  on  this  head ;  but  if  it  can  be 
shown  that  man  now  varies — that  his  variations  are  in- 
duced by  the  same  general  causes,  and  obey  the  same 
general  laws,  as  in  the  case  of  the  lower  animals — tliere 
can  be  little  doubt  that  the  preceding  intermediate  links 


]04  THE   DESCENT   OF  MAN.  [Part  I. 

varied  in  a  like  manner.  The  variations  at  each  succes- 
sive stage  of  descent  must,  also,  liave  been  in  some  man- 
ner accumulated  and  fixed. 

The  facts  and  conclusions  to  be  given  in  this  chapter 
relate  almost  exclusively  to  the  probable  means  by  which 
the  transformation  of  man  has  been  effected,  as  far  as  his 
bodily  structure  is  concerned.  The  following  chapter  will 
be  devoted  to  the  develoi^ment  of  his  intellectual  and 
moral  faculties.  But  the  present  discussion  likewise  bears 
on  the  origin  of  the  different  races  or  species  of  mankind, 
whichever  term  may  be  preferred. 

It  is  manifest  that  man  is  now  subject  to  much  varia- 
bility. No  two  individuals  of  the  same  race  are  quite 
alike.  We  may  compare  millions  of  faces,  and  each  will 
be  distinct.  There  is  an  equally  great  amount  of  diversity 
in  the  proportions  and  dimensions  of  the  various  parts  of 
the  body ;  the  length  of  the  legs  being  one  of  the  most 
variable  points.*  Although  in  some  quarters  of  the  world 
an  elongated  skull,  and  in  other  quarters  a  short  skull  pre- 
vails, yet  there  is  great  diversity  of  shape  even  within  the 
limits  of  the  same  race,  as  with  the  aborigines  of  America 
and  South  Australia — the  latter  a  race  "  probably  as  pure 
and  homogeneous  in  blood,  customs,  and  language,  as  any 
in  existence  " — and  even  with  the  inhabitants  of  so  con- 
fined an  area  as  the  Sandwich  Islands.^  An  eminent  den- 
tist assures  me  that  there  is  nearly  as  much  diversity  in 
the  teeth  as  in  the  features.  The  chief  arteries  so  fre- 
quently run  in  abnormal  courses,  that  it  has  been  found 
useful  for    surgical   purposes   to   calculate   from   12,000 

'  '  Investigations  in  Military  and  Anthropolog.  Statistics  of  American 
Soldiers,'  by  B.  A.  Gould,  1869,  p.  256. 

*  With  respect  to  tbe  "  Cranial  forms  of  the  American  aborigines," 
see  Dr.  Aitken  Meigs  in  'Proc.  Acad.  Nat.  Sci.'  Philadelphia,  May,  1S66. 
On  the  Australians,  see  Huxley,  in  Lyell's  'Antiquity  of  Man,'  1803,  p.  87. 
Ou  the  Sandwich  Islanders,  Prof.  J.  Wyman,  '  Observations  on  Crania,' 
Boston,  1868,  p.  18. 


Chap.  IV.]  MANNER   OF   DEVELOPMENT.  105 

corpses  how  often  each  course  prevails.'  The  muscles  are 
eminently  variable  ;  thus  those  of  the  foot  were  found  by 
Prof.  Turner  *  not  to  be  strictly  alike  in  any  two  out  of 
fifty  bodies ;  and  in  some  the  deviations  were  considerable. 
Prof.  Turner  adds  that  the  power  of  jDcrforming  the  ap- 
proj)riate  movements  miist  have  been  modified  in  accord- 
ance with  the  several  deviations.  Mr.  J.  Wood  has  re- 
corded* the  occurrence  of  295  muscular  variations  in 
thirty-six  subjects,  and  in  another  set  of  the  same  number 
no  less  than  558  variations,  reckoning  both  sides  of  the 
body  as  one.  In  the  last  set,  not  one  body  out  of  the 
thirty-six  was  "  found  totally  Avanting  in  departures  from 
the  standard  descriptions  of  the  muscular  system  given 
in  anatomical  text-books."  A  single  body  presented  the 
extraordinary  number  of  twenty-five  distinct  abnormali- 
ties. The  same  muscle  sometimes  varies  in  many  ways  : 
thus  Prof.  Macalister  describes  °  no  less  than  twenty  dis- 
tinct variations  in  the  palmaris  accessorius. 

The  famous  old  anatomist,  Wolff,'  insists  that  the  in- 
ternal viscera  are  more  variable  than  the  external  parts : 
N-ulla  particula  est  quce  non  allter  et  aliter  in  aliis  se 
hdbeat  hominihus.  He  has  even  written  a  treatise  on  the 
choice  of  typical  examples  of  the  viscera  for  representation.' 
A  discussion  on  the  beau-ideal  of  the  liver,  lungs,  kidneys, 
etc.,  as  of  the  human  face  divine,  sounds  strange  in  our 
ears. 

The  variability  or  diversity  of  the  mental  faculties  in 
men  of  the  same  race,  not  to  mention  the  greater  differ- 
ences between  the  men  of  distinct  races,  is  so  notorious 

3  '  Anatomy  of  the  Arteries,'  by  R.  Quain. 
*  'Transact.  Royal  Sec'  Edinburgh,  vol.  xxiv.  pp.  lYo,  189. 
^  '  Proc.  Royal  Soc'  186Y,  p.  544  ;  also  1868,  pp.  483,  524.     There  ia 
a  previous  paper,  1866,  p.  229. 

^  'Proc.  R.  Irish  Academy,'  vol.  x.  1868,  p.  141. 
'  'Act.  Acad.,'  St.  Petersburg,  I'Z'JS,  part  ii.  p.  217. 


-i 


106  THE   DESCENT   OF  MAX.  [Part  I. 

tliat  not  a  -word  need  here  be  said.  So  it  is  with  the  lower 
animals,  as  has  been  illustrated  by  a  few  examples  in  the 
last  chapter.  All  who  have  had  charge  of  menageries 
admit  this  fact,  and  we  see  it  plainly  in  our  dogs  and  other 
domestic  animals.  Brchm  especially  insists  that  each  in- 
dividual monkey  of  tliosc  which  he  kept  under  confine- 
ment in  Africa  had  its  own  peculiar  disposition  and  tem- 
per :  he  mentions  one  baboon  remarkable  for  its  high  in- 
telligence ;  and  the  keepers  in  the  Zoological  Gardens 
pointed  out  to  me  a  monkey,  belonging  to  the  New  World 
division,  equally  remarkable  for  intelligence.  Rengger, 
also,  insists  on  the  diversity  in  the  various  mental  charac- 
ters of  the  monkeys  of  the  same  species  which  he  kept  in 
Paraguay;  and  this  diversity,  as  he  adds, is  partly  innate, 
and  partly  the  result  of  the  manner  in  which  they  have 
been  treated  or  educated.' 

I  have  elsewhere®  so  fully  discussed  the  subject  of  In- 
heritance that  I  need  here  add  hardly  any  thing.  A 
greater  number  of  facts  have  been  collected  with  respect 
to  the  transmission  of  the  most  trifling,  as  well  as  of  the 
most  important  characters  in  man  than  in  any  of  the  lower 
animals ;  though  the  facts  are  copious  enough  with  respect 
to  the  latter.  So  in  regard  to  mental  qualities,  their  trans- 
mission is  manifest  in  our  dogs,  horses,  and  other  domes- 
tic animals.  Besides  special  tastes  and  habits,  general  in- 
telligence, courage,  bad  and  good  temper,  etc.,  are  cer- 
tainly transmitted.  "With  man  we  see  similar  facts  in  al- 
most every  family  ;  and  we  now  know  through  the  admi- 
rable labors  of  Mr.  Galton '"  that  genius,  which  implies  a 

*  Brehm,   '  Thierleben,'  B.  i.   s.  58,  87.     Rengger,  '  Siiugethiere  von 
Paraguay,'  s.  57. 

*  '  Variation  of  Animals  and  Plants  under  Domestication,'  vol.  ii.  chap, 
xii. 

'"  '  Hereditary  Genius :  an  Inquiry  into  its  Laws  and  Consequences,' 
18C9. 


Chap.  IV.]  MANNER   OF  DEVELOPMENT.  107 

wonderfully  complex  combination  of  high  faculties,  tends 
to  be  inherited ;  and,  on  the  other  hand,  it  is  too  certain 
that  insanity  and  deteriorated  mental  powers  likewise  run 
in  the  same  families. 

With  respect  to  the  causes  of  variability  we  are  in  all 
cases  very  ignorant ;  but  we  can  see  that  in  man  as  in  the 
lower  animals,  they  stand  in  some  relation  with  the  con- 
ditions to  which  each  species  has  been  exposed  during 
several  generations.  Domesticated  animals  vary  more 
than  those  in  a  state  of  nature ;  and  this  is  apparently  due 
to  the  diversified  and  changing  nature  of  their  conditions. 
The  different  races  of  man  resemble  in  this  respect  domes- 
ticated animals,  and  so  do  the  individuals  of  the  same 
race  when  inhabiting  a  very  wide  area,  like  that  of 
America.  We  see  the  influence  of  diversified  conditions 
in  the  more  civilized  nations,  the  members  of  which  be- 
long to  different  grades  of  rank  and  follow  different  occu- 
pations, presenting  a  greater  range  of  character  than  the 
members  of  barbarous  nations.  Bvit  the  uniformity  of 
savages  has  often  been  exaggerated,  and  in  some  cases  can 
hardly  be  said  to  exist."  It  is  nevertheless  an  error  to 
speak  of  man,  even  if  we  look  only  to  the  conditions 
to  which  he  has  been  subjected,  as  "  far  more  domesti- 
cated "  "  than  any  other  animal.  Some  savage  races,  such 
as  the  Australians,  are  not  exposed  to  more  diversified 
conditions  than  are  many  species  which  have  very  wide 
ranges.  In  another  and  much  moi-e  important  respect, 
man  differs  widely  from  any  strictly-domesticated  animal ; 

''  Mr.  Bates  remarks  ('  Tbe  Naturalist  on  the  Amazons,'  1863,  vol.  ii. 
p.  159),  with  respect  to  the  Indians  of  the  same  South-American  tribe, 
"  No  two  of  them  were  at  all  similar  in  the  shape  of  the  head ;  one  man 
had  an  oval  visage  with  fine  features,  and  another  was  quite  Mongolian 
in  breadth  and  prominence  of  cheek,  spread  of  nostrils,  and  obliquity  of 
Byes." 

'^  Blumenbach,  'Treatises  on  Anthropolog.'  Eng.  translat.,  1865,  p.  205. 


108  THE   DESCENT   OF  MAN.  [Fart  I. 

for  his  breeding  has  not  been  controlled,  either  througli 
methodical  or  unconscious  selection.  No  race  or  body  of 
men  has  been  so  completely  subjugated  by  other  men, 
that  certain  individuals  have  been  j^reserved  and  tlius  un- 
consciously selected,  from  being  in  some  way  more  useful 
to  their  masters.  Nor  have  certain  male  and  female  in- 
dividuals been  intentionally  picked  out  and  matched,  ex- 
cept in  the  well-known  case  of  the  Prussian  grenadiers ; 
and  in  this  case  man  obeyed,  as  might  have  been  expect- 
ed, the  law  of  methodical  selection ;  for  it  is  asserted  that 
many  tall  men  were  reared  in  the  villages  inhabited  by 
the  grenadiers  with  their  tall  wives. 

If  we  consider  all  the  races  of  man,  as  forming  a  single 
species,  his  range  is  enormous ;  but  some  separate  races, 
as  the  Americans  and  Polynesians,  have  very  wide  ranges. 
It  is  a  well-known  law  that  widely-ranging  species  are 
much  more  variable  than  species  with  restricted  ranges  ; 
and  the  variability  of  man  may  with  more  truth  be  com- 
pared with  that  of  widely-ranging  species,  than  with  that 
of  domesticated  animals. 

Not  only  does  variability  appear  to  be  induced  in  man 
and  the  lower  animals  by  the  same  general  causes,  but  in 
both  the  same  characters  are  affected  in  a  closely  analo- 
gous manner.  This  has  been  proved  in  such  full  detail 
by  Godron  and  Quatrefages,  that  I  need  here  only  refer 
to  their  Avorks."  Monstrosities,  which  graduate  into 
slight  valuations,  are  likewise  so  similar  in  man  and  the 
loAver  animals,  that  the  same  classification  and  the  same 
terms  can  be  used  for  both,  as  may  be  seen  in  Isidore 
Geoffroy  St.-Hilaire's  great  work."     This  is  a  necessary 

'2  Godron,  '  De  I'Esptice,'  1859,  torn.  ii.  livre  3.  Quatrefages,  'Unit6 
de  I'Especc  Humaine,'  18G1.  Also  Lectures  on  Anthropology,  given  in 
the  'Revue  des  Cours  Scientifiques,'  186G-18G8. 

'■* '  Hist.  Gen.  et  Part,  des  Anomalies  de  rOrganisation,'  in  three  vol 
umes,  torn.  i.  1832. 


Chap.  IV.]  MANNER  OF  DEVELOPMENT.  109 

consequence  of  the  same  laws  of  change  prevailing 
throughout  the  animal  kingdom.  In  my  work  on  the 
variation  of  domestic  animals,  I  have  attempted  to  ar- 
range in  a  rude  fashion  the  laws  of  variation  under 
the  following  heads:  The  direct  and  definite  action  of 
changed  conditions,  as  shown  by  all  or  nearly  all  the  in- 
dividuals of  the  same  species  varying  in  the  same  manner 
under  the  same  circumstances.  The  effects  of  the  long- 
continued  use  or  disuse  of  parts.  The  cohesion  of  homol- 
ogous parts.  The  variability  of  multiple  parts.  Com- 
pensation of  growth ;  but  of  this  law  I  have  found  no 
good  instances  in  the  case  of  man.  The  effects  of  the  me- 
chanical pressure  of  one  part  on  another ;  as  of  the  pelvis 
on  the  cranium  of  the  infant  in  the  Avomb.  Arrests  of  de- 
velopment, leading  to  the  diminution  or  suppression  of 
parts.  The  reappearance  of  long-lost  characters  through 
reversion.  And  lastly,  correlated  variation.  All  these 
so-called  laws  apply  equally  to  man  and  the  lower  ani- 
mals ;  and  most  of  them  even  to  plants.  It  would  be 
superfluous  here  to  discuss  all  of  them ;  '^  but  several  are 
so  important  for  us,  that  they  must  be  treated  at  consider- 
able length. 

The  direct  and  definite  action  of  changed  conditions. — 
This  is  a  most  perplexing  subject.  It  cannot  be  denied 
that  changed  conditions  produce  some  effect,  and  occa- 
sionally a  considerable  effect,  on  organisms  of  all  kinds : 
and  it  seems  at  first  probable  that,  if  sufficient  time  were 
allowed,  this  would  be  the  invariable  result.  But  I  have 
failed  to  obtain  clear  evidence  in  favor  of  this  conclusion ; 
and  valid  reasons  may  be  urged  on  the  other  side,  at  least 

^^  I  have  fully  discussed  these  laws  in  my  '  Variation  of  Animals  and 
Plants  under  Domestication,'  vol.  ii.  chaps,  xxii.  and  xxiii.  M.  J.  P. 
Durand  has  lately  (1868)  published  a  valuable  essay,  'Del'Influence  des 
Milieux,'  etc.     He  lays  much  stress  on  the  nature  of  the  soil. 


110  THE   DESCENT   OF   MAN.  [Part  I. 

as  far  as  the  innumerable  structures  are  concerned,  which 
are  adapted  for  special  ends.  Tliere  can,  however,  he  no 
doubt  that  changed  conditions  induce  an  almost  indefinite 
amount  of  fluctuating  variability,  by  which  the  whole  or- 
ganization is  rendered  in  some  degree  plastic. 

In  the  United  States,  above  1,000,000  soldiers,  who 
served  in  the  late  war,  were  measured,  and  the  States  in 
which  they  were  born  and  reared  recorded."  From  this 
astonishing  number  of  observations  it  is  proved  that  local 
influences  of  some  kind  act  directly  on  stature ;  and  we 
further  learn  that  "  the  State  where  the  physical  growth 
has  in  great  measure  taken  place,  and  the  State  of  birth, 
which  indicates  the  ancestry,  seem  to  exert  a  marked  in- 
fluence on  the  stature."  For  instance,  it  is  established, 
"  that  residence  in  the  "Western  States,  during  the  years 
of  growth,  tends  to  produce  increase  of  stature."  On  the 
otlier  hand,  it  is  certain  that  with  sailors,  their  manner  of 
life  delays  growth,  as  shown  "  by  the  great  difierence  be- 
tween the  statures  of  soldiers  and  sailors  at  the  ages  of 
seventeen  and  eigliteen  years."  Mr.  B.  A.  Gould  en- 
deavored to  ascertain  the  nature  of  the  influences  which 
thus  act  on  stature ;  but  he  arrived  only  at  negative 
results,  namely,  that  they  did  not  relate  to  climate,  the 
elevation  of  the  land,  soil,  or  even  "  in  any  controlling 
degree  "  to  the  abundance  or  need  of  the  comforts  of  life. 
This  latter  conclusion  is  directly  opposed  to  that  arrived 
at  by  Villermc  from  the  statistics  of  the  height  of  the  con- 
scripts in  difierent  parts  of  France.  When  we  compare 
the  difierences  in  stature  between  the  Polynesian  chiefs 
and  the  lower  orders  within  the  same  islands,  or  between 
the  inhabitants  of  the  fertile  volcanic  and  low  barren 
coral  islands  of  the  same  ocean,"  or  again  between  the 

'•  'Investigations  in  Military  and  Anthrop.  Statistics,'  etc.,  1869,  by 
B.  A.  Gould,  pp.  93,  107,  126,  131,  134. 

"  For  the  Polynesians,  see  Prichard's  '  Physical  Hist,  of  Mankind,* 


Chap.  IV.l  MANNER   OF  DEVELOPMENT.  HI 

Fuegians  on  the  eastern  and  western  shores  of  tlieir 
country,  where  the  means  of  subsistence  are  very  dif- 
ferent, it  is  scarcely  possible  to  avoid  the  conclusion  that 
better  food  and  greater  comfort  do  influence  stature. 
But  the  preceding  statements  show  how  difficult  it  is 
to  arrive  at  any  precise  result.  Dr.  Beddoe  has  lately 
proved  that,  with  the  inhabitants  of  Britain,  residence  in 
town  and  certain  occupations  have  a  deteriorating  in- 
fluence on  height ;  and  he  infers  that  the  result  is  to  a 
certain  extent  inherited,  as  is  likewise  the  case  in  the 
United  States.  Dr.  Beddoe  further  believes  that  wherever 
a  "  race  attains  its  maximum  of  physical  development,  it 
rises  highest  in  energy  and  moral  vigor."  " 

Whether  external  conditions  produce  any  other  direct 
eflfect  on  man  is  not  known.  It  might  have  been  expected 
that  differences  of  climate  would  have  had  a  marked  in- 
fluence, as  the  lungs  and  kidneys  are  brought  into  fuller 
activity  under  a  low  temperature,  and  the  liver  and  skin 
under  a  high  one."  It  was  formerly  thought  that  the 
color  of  the  skin  and  the  character  of  the  hair  were  de- 
termined by  light  or  heat ;  and  although  it  can  hardly  be 
denied  that  some  effect  is  thus  produced,  almost  all  ob- 
servers now  agree  that  the  effect  has  been  very  small, 
even  after  exposure  during  many  ages.  But  this  subject 
will  be  more  properly  discussed  when  we  treat  of  the  dif- 
ferent races  of  mankind.  With  our  domestic  animals 
there  are  grounds  for  believing  that  cold  and  damp  direct- 
ly affect  the  growth  of  the  hair ;  but  I  have  not  met  with 
any  evidence  on  this  head  in  the  case  of  man. 

vol.  V.  1847,  pp.  145,  283.  Also  Godron,  'De  I'Espece,'  torn.  ii.  p.  289. 
There  is  also  a  remarkable  difference  in  appearance  between  the  closely- 
allied  Hindoos  inhabiting  the  Upper  Ganges  and  Bengal ;  see  Elphin- 
stone's  'History  of  India,'  vol.  i.  p.  324. 

18  Memoirs,  ' Anthropolog.  See'  vol.  iii.  ISeT-GQ,  pp.  561,  565,  567. 

"  Dr.  Brakenridge,  '  Theory  of  Diathesis,'  'Medical  Times,'  June  19 
and  July  17,  1869. 


112  THE  DESCENT   OF   MAX.     ^  [Fart  I. 

Effects  of  the  increased  Use  and  Disuse  of  Parts. — 
It  is  well  known  tliat  use  strengthens  the  muscles  in  the 
individual,  and  complete  disuse,  or  the  destruction  of  the 
proper  nerve,  weakens  them.  When  the  eye  is  destroyed 
the  optic  nerve  often  becomes  atrophied.  When  an  artery 
is  tied,  the  lateral  channels  increase  not  only  in  diameter, 
but  in  the  thickness  and  strength  of  their  coats.  When 
one  kidney  ceases  acting  from  disease,  the  other  increases 
in  size  and  does  double  work.  Bones  increase  not  only  in 
thickness,  but  in  length,  from  carrying  a  greater  weight.'"* 
Different  occupations  habitually  followed  lead  to  changed 
proportions  in  various  parts  of  the  body.  Thus  it  was 
clearly  ascertained  by  the  United  States  Commission** 
that  the  legs  of  the  sailors  employed  in  the  late  war  were 
longer  by  0.217  of  an  inch  than  those  of  the  soldiers, 
though  the  sailors  were  on  an  average  shorter  men ; 
while  their  arms  were  shorter  by  1.09  of  an  inch,  and 
therefore  out  of  proportion  shorter  in  relation  to  their 
lesser  height.  This  shortness  of  the  arms  is  apparently 
due  to  their  greater  use,  and  is  an  unexpected  result ;  but 
sailors  chiefly  use  their  arms  in  pulling  and  not  in  sup- 
porting weights.  The  girth  of  the  neck  and  the  depth  of 
the  instep  are  greater,  while  the  circumference  of  the 
chest,  waist,  and  hips,  is  less  in  sailors  than  in  soldiers. 

Whether  the  several  foregoing  modifications  would  be- 
come hereditary,  if  the  same  habits  of  life  were  followed 
dui'ing  many  generations,  is  not  known,  but  is  probable. 
Rengger"'  attributes  the  thin  legs  and  thick  arms  of  the 
Payaguas  Indians  to  successive  generations  having  passed 

-<•  I  have  given  authorities  for  these  several  statements  in  my  '  Varia- 
tion of  Animals  under  Domestication,'  vol.  ii.  pp.  297-300.  Dr.  Jaeger, 
"  Ueber  das  Langenwachsthum  der  Knochen,"  '  Jenaischen  Zeitschrift,' 
B.  V.  Heft  i. 

"  'Investigations,'  etc.     By  B.  A.  Gould,  1809,  p.  283. 

"  'Saugethiere  von  Paraguay,'  1830,  s.  4. 


Chap.  IV.]  MANNER   AND   DEVELOPMENT.  113 

nearly  their  whole  lives  in  canoes,  with  their  lower 
extremities  motionless.  Other  writers  have  come  to  a 
similar  conclusion  in  other  analoj^ous  cases.  Accordinsj 
to  Cranz,"^  who  lived  for  a  long  time  with  the  Esquimaux, 
"the  natives  believe  that  ingenuity  and  dexterity  in  seal- 
catching  (their  highest  art  and  virtue)  is  hereditary;  there 
is  really  something  in  it,  for  the  son  of  a  celebrated  seal- 
catcher  will  distinguish  himself  though  he  lost  his  father 
in  childhood."  But  in  this  case  it  is  mental  aptitude, 
quite  as  much  as  bodily  structure,  which  appears  to  be 
inherited.  It  is  asserted  that  the  hands  of  English  labor- 
ers are  at  birth  larger  than  those  of  the  gentry.^*  From 
the  correlation  which  exists,  at  least  in  some  cases,^'*  be- 
tween the  development  of  the  extremities  and  of  the  jaws, 
it  is  possible  that  in  those  classes  which  do  not  labor  much 
with  their  hands  and  feet,  the  jaws  v.'ould  be  reduced  in 
size  from  this  cause.  That  they  are  generally  smaller  in 
refined  and  civilized  men  than  in  hard-working  men  or 
saA'ages,  is  certain.  But  with  savages,  as  Mr.  Herbert 
Spencer^"  has  remarked,  the  greater  use  of  the  jaws  in 
chewing  coarse,  uncooked  food,  would  act  in  a  direct  man- 
ner on  the  masticatory  muscles  and  on  the  bones  to  which 
they  are  attached.  In  infants  long  befoi-e  birth,  the  skin 
on  the  soles  of  the  feet  is  thicker  than  on  any  other  part 
of  the  body ; "''  and  it  can  hardly  be  doubted  that  this  is 
due  to  the  inherited  effects  of  pressure  during  a  long 
series  of  generations. 

It  is  familiar  to  every  one  that  watchmakers  and  en- 
gravers are  liable  to  become  short-sighted,  while  sailors 
and  especially  savages  are  generally  long-sighted.     Short- 

-^  'History  of  Greenland,'  Eng.  translat.  1767,  vol.  i.  p.  230. 
-■*  'Intermarriage.'     By  Alex.  Walker,  1838,  p.  377. 
•^  '  The  Variation  of  Animals  under  Domestication,'  vol.  i.  p.  173 
^^  'Principles  of  Biology,'  vol.  i.  p.  455. 

"  Paget,  'Lectures  on  Surgical  Pathology,'  vol.  i.  1853,  p.  209. 
0 


114  THE   DESCENT   OF  MAN.  [Part  I. 

wight  and  long-sight  certainly  tend  to  be  inherited."  The 
inferiority  of  Europeans,  in  comparison  with  savages,  in 
eye-sight  and  in  the  other  senses,  is  no  doubt  the  accumu- 
lated and  transmitted  elTect  of  lessened  use  during  many 
generations  ;  for  Rengger  *°  states  that  he  has  repeatedly 
observed  Europeans,  who  had  been  brought  up  and  spent 
their  whole  lives  with  the  wild  Indians,  who  nevertheless 
did  not  equal  them  in  the  sharpness  of  their  senses.  The 
same  naturalist  observes  that  the  cavities  in  the  skull  for 
the  reception  of  the  several  sense-organs  are  larger  in  the 
American  aborigines  than  in  Europeans ;  and  this  no 
doubt  indicates  a  corresponding  difference  in  the  dimen- 
sions of  the  organs  themselves.  Blumenbach  has  also  re- 
marked on  the  large  size  of  the  nasal  cavities  in  the  skulls 
of  the  American  aborigines,  and  connects  this  fact  with 
their  remarkably  acute  power  of  smell.  The  Mongolians 
of  the  plains  of  Northern  Asia,  according  to  Pallas,  have 
wonderfully  perfect  senses ;  and  Pri chard  believes  that  the 
great  breadth  of  their  skulls  across  the  zygomas  follows 
from  their  highly-developed  sense-organs.^" 

The  Quechua  Indians  inhabit  the  lofty  plateaux  of 
Peru,  and  Alcide  d'Orbigny  states  "  that  from  continually 
breathing  a  highly  rarefied  atmosphere  they  have  acquired 
chests  and  lungs  of  extraoixlinary  dimensions.     The  cells, 

*^  '  The  Tariation  of  Animals  under  Domestication,'  vol.  i.  p.  8. 

"  'Saugethiere  von  Paraguay,'  s.  8,  10.  I  have  had  good  opportuni- 
ties for  observing  the  extraordinary  power  of  eyesight  in  the  Fuegians. 
See  also  Lawrence  ('Lectures  on  Physiology,'  etc.,  1822,  p.  404)  on  this 
same  subject.  M.  Giraud-Teulon  has  recently  collected  ('Eevue  des 
Cours  Scientifiques,'  ISIO,  p.  G25)  a  large  and  valuable  body  of  evidence 
proving  that  the  cause  of  short-sight,  "  C'cst  h  travail  assidii,  de  pres.^' 

*"  Prichard,  'Phys.  Ilist.  of  Mankind,'  on  the  authority  of  Blumen- 
bach, vol.  i.  1851,  p.  311  ;  fur  the  statement  by  Pallas,  vol.  iv.  1844,  p. 
407. 

*'  Quoted  by  Prichard,  '  Researches  into  the  Phys.  Hist,  of  Mankind, 
vol.  V.  p.  463. 


-Chap.  IV.]  MAXNER   OF  DEVELOPMENT.  115 

also,  of  the  lungs  are  larger  and  more  numerous  than  in 
Europeans.     These  observations  have  been  doubted  ;  but 
Mr.  D.  Forbes  carefully  measured  many  Aymaras,  an  allied 
race,  living  at  the  height  of  between  ten  and  fifteen  thou- 
sand feet ;  and  he  informs  me°"  that  they  diifer  conspicu- 
ously from  the  men  of  all  other  races  seen  by  him,  in  the 
circumference  and  length  of  their  bodies.     In  his  table  of 
measurements,  the  stature  of  each  man  is  taken  at  1,000, 
and  the  other  measurements  are  reduced  to  this  standard. 
It  is  here  seen  that  the  extended  arms  of  the  Aymaras  are 
shorter  than  those  of  Europeans,  and  much  shorter  than 
those  of  Negroes.     The  legs  are  likewise  shorter,  and  they 
present  this  remarkable  peculiarity,  that  in  every  Aymara 
measured  the  femur  is  actually  shorter  than  the  tibia.    On 
an  average  the  length  of  the  femur  to  that  of  the  tibia  is 
as  211  to  252  ;  while  in  two  Europeans  measured  at  the 
same  time,  the  femora  to  the  tibia?  were  as  244  to  230  ; 
and  in  three  Negroes  as  258  to  241.     The  humerus  is  like- 
wise shorter  relatively  to  the  forearm.     This  shortening 
of  that  part  of  the  limb  which  is  nearest  to  the  body,  a-p- 
pears  to  be,  as  suggested  to  me  by  Mr.  Forbes,  a  case  of 
compensation  in  relation  with  the  greatly-increased  length 
of  the  trunk.     The  Aymaras  present  some  other  singular 
points  of  structure,  for  instance,  the  very  small  projection 
of  the  heel. 

Tliese  men  are  so  thoroughly  acclimatized  to  their  cold 
and  lofty  abode,  that  when  formerly  carried  down  by  the 
Spaniards  to  the  low  eastern  plains,  and  when  now  tempt- 
ed down  by  high  wages  to  the  gold-washings,  they  suffer 
a  frightful  rate  of  mortality.  Nevertheless,  Mr.  Forbes 
found  a  few  pure  families  which  had  survived  during  two 
generations ;  and  he  observed  that  they  still  inherited 
their  characteristic  peculiarities.      But  it  was   manifest, 

32  Mr.  Forbes's  valuable  paper  is  now  published  in  the  '  Journal  of  the 
Ethnological  Soc.  of  London,'  new  series,  vol.  ii.  ISTO,  p.  193. 


116  THE  DESCENT   OF   MAN.  [Paut  I. 

even  williout  measurement,  tliat  tliesc  peculiarities  bad  all 
decreased  ;  and  on  measurement  their  bodies  were  found 
not  to  be  so  much  elongated  as  those  of  the  men  on  the 
high  plateau ;  while  their  femora  had  become  somewhat 
lengthened,  as  had  their  tibia3,  but  in  a  less  degree.  The 
actual  measurements  may  be  seen  by  consulting  Mr. 
Forbcs's  memoir.  From  these  valuable  observations,  there 
can,  I  think,  be  no  doubt  that  residence  during  many  gen- 
erations at  a  great  elevation  tends,  both  directly  and  indi- 
rectly, to  induce  inherited  modifications  in  the  proportions 
of  the  body.'' 

Although  man  may  not  have  been  much  modified  dur- 
ing the  latter  stages  of  his  existence  through  the  increased 
ror  decreased  use  of  parts,  the  facts  now  given  show  that 
liis  liability  in  this  respect  has  not  been  lost ;  and  we  posi- 
'  tively  know  that  the  same  laAV  holds  good  with  the  lower 
animals.  Consequently  we  may  infer  that,  when  at  a  re- 
mote epoch  the  progenitors  of  man  were  in  a  transitional 
state,  and  were  changing  from  cpiadrupeds  into  bipeds, 
nntural  selection  would  probably  have  been  greatly  aided 
by  the  inherited  effects  of  the  increased  or  diminished  use 
of  the  different  parts  of  the  body. 

Arrests  of  Development. — Arrested  development  dif- 
fers from  arrested  growth,  as  parts  in  the  former  state 
continue  to  grow  while  still  retaining  their  early  condi- 
tion. Various  monstrosities  corac  under  this  liead,  and 
some  are  known  to  be  occasionally  inherited,  as  a  cleft- 
palate.  It  will  sufiice  for  our  purpose  to  refer  to  the 
arrested  brain-development  of  microcephalous  idiots,  as 
described  in  Vogt's  great   memoir.'*     Their   skulls   are 

33  Dr.  Wilckcns  (' Landwirthschaft.  Wochcnblatt,'  No.  10,  1869)  has 
lately  pul)lislicd  an  interesting  essay  showing  how  domestic  animals, 
wliifli  live  in  mountainous  regions,  have  their  frames  modified. 

3^  'Menioire  sur  Ics  Mierocephalos,'  18d7,  pp.  50,  125,  ICO,  l^l,  1S4, 
19S. 


CnAP.  IV.]  MANNER  OF   DEVELOPMENT.  H7 

smaller,  and  the  convolutions  of  the  brain  are  less  com- 
plex, than  in  normal  men.  The  frontal  sinus,  or  the  pro- 
jection over  the  eyebrows,  is  largely  developed,  and  the 
jaws  are  prognathous  to  an  "  effrayant "  degree  ;  so  that 
these  idiots  somewhat  resemble  the  lower  types  of  man- 
kind. Their  intelligence  and  most  of  their  mental  facul- 
ties are  extremely  feeble.  They  cannot  acqiiire  the  power 
of  speech,  and  are  wholly  incapable  of  prolonged  atten- 
tion, but  are  much  given  to  imitation.  They  are  strong 
and  remarkably  active,  continually  gambolling  and  jump- 
ing about,  and  making  grimaces.  They  often  ascend 
stairs  on  all-fours  ;  and  are  curiously  fond  of  climbing  up 
furniture  or  trees.  We  are  thus  reminded  of  the  delight 
shown  by  almost  all  boys  in  climbing  trees;  and  this 
again  reminds  us  how  lambs  and  kids,  originally  alpine 
animals,  delight  to  frisk  on  any  hillock,  howevei  small. 

Meversion. — Many  of  the  cases  to  be  here  given  might 
have  been  introduced  under  the  last  heading.  Whenever 
a  structure  is  arrested  in  its  development,  but  still  con- 
tinues growing  until  it  closely  resembles  a  corresponding 
structure  in  some  lower  and  adult  member  of  the  same 
group,  we  may  in  one  sense  consider  it  as  a  case  of  rever- 
sion. The  lower  members  in  a  group  give  us  some  idea 
how  the  common  progenitor  of  the  group  was  probably 
constructed ;  and  it  is  hardly  credible  that  a  part  arrested 
at  an  early  phase  of  embryonic  development  should  be 
enabled  to  continue  growing  so  as  ultimately  to  perform 
its  proper  function,  unless  it  had  acquired  this  power  of 
continued  growth  during  some  earlier  state  of  existence, 
when  the  present  exceptional  or  arrested  structure  was 
normal.  The  simple  brain  of  a  microcephalous  idiot,  in  as 
Ihr  as  it  resembles  that  of  an  ape,  may  in  this  sense  be 
said  to  offer  a  case  of  reversion.  There  are  other  cases 
which  come  more  strictly  under  our  present  heading  of 


118  THE   DESCENT   OF  MAX.  [Part  I. 

reversion.  Certain  structures,  regularly  occurring  in  the 
lower  members  of  the  group  to  which  man  belongs,  occa- 
sionally make  their  appearance  in  him,  though  not  found 
in  the  normal  human  embryo  ;  or,  if  present  in  the  nor- 
mal human  embryo,  they  become  developed  in  an  abnor- 
mal manner,  though  this  manner  of  development  is  proper 
to  the  lower  members  of  the  same  group.  These  remarks 
will  be  rendered  clearer  by  the  following  illustrations. 

In  various  mammals  the  uterus  graduates  from  a  double 
organ  with  two  distinct  orifices  and  two  passages,  as  in  the 
marsuj^ials,  into  a  single  oi-gan,  showing  no  signs  of  double- 
ness  except  a  slight  internal  fold,  as  in  the  higher  apes  and 
man.  The  rodents  exhibit  a  perfect  series  of  gradations 
between  these  two  extreme  states.  In  all  mammals  the 
uterus  is  developed  from  two  simple  i")rimitive  tubes,  the 
inferior  portions  of  which  form  the  cornua ;  and  it  is  in 
the  words  of  Dr.  Farre  "  by  the  coalescence  of  the  two 
cornua  at  their  lower  extremities  that  the  body  of  the 
uterus  is  formed  in  man  ;  while  in  those  animals  in  which 
no  middle  portion  or  body  exists,  the  cornua  remain  un- 
united. As  the  development  of  the  utei'us  proceeds,  the 
two  cornita  become  gradually  shorter,  until  at  length  they 
are  lost,  or,  as  it  were,  absorbed  into  the  body  of  the 
uterus."  The  angles  of  the  uterus  are  still  produced  into 
cornua,  even  so  high  in  the  scale  as  in  the  lower  apes,  and 
their  allies  the  lemurs. 

Xow  in  Avomen  anomalous  cases  are  not  very  infre- 
quent, in  which  the  mature  uterus  is  furnished  with  cor- 
nua, or  is  partially  divided  into  two  organs ;  and  such 
cases,  according  to  Owen,  repeat  "the  grade  of  conccn- 
trative  development,"  attained  by  certain  rodents.  Here 
perhaps  we  have  an  instance  of  a  simple  arrest  of  embry- 
onic development,  with  subsequent  growth  and  perfect 
functional  development,  for  either  side  of  the  partially 
double  uterus  is  capable  of  performing  the  proper  office 


Chap.  lY.]  MANNER   OF  DEVELOPMENT.  119 

of  gestation.  In  other  and  rarer  cases,  two  distinct  uter- 
ine ca,vities  are  formed,  each  having  its  proper  orifice  and 
passage.  °*  No  such  stage  is  passed  through  during  the 
ordinary  development  of  the  embryo,  and  it  is  difficult  to 
believe,  though  perhaj^s  not  impossible,  that  the  two  sim- 
ple, minute,  primitive  tubes  could  know  how  (if  such  an 
expression  may  be  used)  to  grow  into  two  distinct  uteri, 
each  with  a  well-constructed  orifice  and  passage,  and  each 
furnished  with  numerous  muscles,  nerves,  glands  and  ves- 
sels, if  they  had  not  formerly  passed  through  a  similar 
course  of  development,  as  in  the  case  of  existing  marsu- 
pials, No  one  will  pretend  that  so  perfect  a  structure  as 
tho  abnornal  double  uterus  in  woman  could  be  the  result 
of  mere  chance.  But  the  principle  of  reversion,  by  which 
long-lost  dormant  structures  are  called  back  into  exist- 
ence, might  serve  as  the  guide  for  the  full  development 
of  the  organ,  even  after  the  lapse  of  an  enormous  intei'val 
of  time. 

Prof.  Canestrini,'*  after  discussing  the  foregoing  and 
various  analogous  cases,  arrives  at  the  same  conclusion  as 
that  just  given.  He  adduces,  as  another  instance,  the 
malar  bone,  which,  in  some  of  the  Quadrumana  and  other 
mammals,  normally  consists  of  two  portions.  This  is  its 
condition  in  the  two-months-old  human  foetus ;  and  thus  it 
sometimes  remains,  through  arrested  development,  in  man 
when  adult,  more  especially  in  the  lower  prognathous 
races.     Hence   Canestrini  concludes   that   some   ancient 

''=  See  Dr.  A.  Farre's  well-known  article  in  the  '  Cyclop,  of  Anat.  and 
Pliys.'  vol.  V.  1859,  p.  642.  Owen,  'Anatomy  of  Vertebrates,'  voL  iii. 
1868,  p.  GST.     Prof.  Turner  in  'Edinburgh  Medical  Journal,'  Feb.  1865. 

2^  '  Anuiiario  della  See.  dei  Naturahsti  in  Modena,'  1867,  p.  83.  Prof. 
Canestrini  gives  extracts  en  this  subject  from  various  authorities.  Lau- 
rillard  remarks  that,  as  he  has  found  a  complete  similarity  in  the  form, 
proportions,  and  connection  of  the  two  malar  bones  in  several  human 
subjects  and  in  certain  apes,  he  cannot  consider  this  disposition  of  the 
parts  aa  simply  accidental. 


120  THE   DESCENT   OF   MAN.  [Paut  I. 

progenitor  of  man  must  Lave  possessed  this  Lone  nor- 
mally divided  into  two  portions,  which  subsequently  be- 
came fused  together.  In  man  the  frontal  bone  consists  of 
a  single  piece,  but  in  the  embrj^o  and  in  children,  and  in 
almost  all  the  lower  mammals,  it  consists  of  two  pieces  sepa- 
rated by  a  distinct  suture.  This  suture  occasionally  per- 
sists, more  or  less  distinctly,  in  man  after  maturity,  and 
more  frequently  in  ancient  than  in  recent  crania,  especially 
as  Canestrinihas  observed  in  those  exhumed  from  the  Drift 
and  belonging  to  the  brachycephalic  type.  Here  again  he 
comes  to  the  same  conclusion  as  in  the  analogous  case  of 
the  malar  bones.  In  this  and  other  instances  presently  to 
be  given,  the  cause  of  ancient  races  approaching  the  lower 
animals  in  certain  characters  more  frequently  than  do  the 
modern  races,  appears  to  be  that  the  latter  stand  at  a 
somewhat  greater  distance  in  the  long  line  of  descent 
from  then-  early  semi-human  progenitors. 

Various  other  anomalies  in  man,  more  or  less  anal- 
ogous with  the  foregoing,  have  been  advanced  by  dif- 
ferent authors  "  as  cases  of  reversion ;  but  these  seem  not 
a  little  doiibtful,  for  we  have  to  descend  extremely  low  in 
the  mammalian  scries  before  we  find  such  structures  nor- 
mally present.'^ 

^^  A  ■whole  series  of  cases  is  given  by  Isid.  Geoffrey  St.-IIilairc, 
'  Hist,  des  Anomalies,'  torn.  iii.  p.  437. 

2^  In  my  '  Variation  of  Animals  under  Domcglicaticn '  (vol.  ii.  p.  O'i') 
I  attributed  the  not  very  rare  cases  of  supernumerary  mammae  in  women 
to  reversion.  I  was  led  to  this  as  a  proballc  conclusion,  by  the  additional 
mammaj  being  generally  placed  symmetrically  on  the  breast,  and  more 
especially  from  one  case,  in  which  a  single  efficient  mamma  occurred  in 
the  inguinal  region  of  a  woman,  the  daughter  of  another  woman  with 
supernumerary  mamma?.  But  Prof.  Preycr  ('  Dcr  Kampf  um  das  Dasein,' 
1SG9,  s.  45)  states  that  mammm  crralica:  have  been  known  to  occur  in 
other  situations,  even  on  the  back ;  so  that  tlic  force  of  my  argument  is 
greatly  weakened  or  perhaps  quite  destroyed. 

With  much  hesitation  I,  in  the  same  work  (vol.  ii.,  p.  12),  attributed 
the  frequent  cases  of  polydactylism  in  men  to  reversion.    I  was  partly  led 


Chap.  IV.]  MANNER   OF   DEVELOPMENT.  121 

In  man  the  canine  teeth  are  perfectly  efficient  instru- 
ments for  mastication.  But  their  true  canine  character,  as 
Owen^"  remarks,  "is  indicated  by  the  conical  form  of  the 
croAvn,  which  terminates  in  an  obtuse  point,  is  convex  out- 
ward and  flat  or  subconcave  within,  at  the  base  of  which 
surfoce  there  is  a  feeble  prominence.  The  conical  form  is 
best  expressed  in  the  Melanian  races,  especially  the 
Australian.  The  canine  is  more  deeply  implanted,  and  by 
a  stronger  fang,  than  the  incisors."  Nevertheless  this  tooth 
no  longer  serves  man  as  a  special  weapon  for  tearing  his 
enemies  or  prey ;  it  may,  therefore,  as  far  as  its  proper 
function  is  concerned,  be  considered  as  rudimentary.  In 
every  lai'ge  collection  of  human  skulls  some  may  be  found, 
as  Hackel*"  observes,  with  the  canine  teeth  projecting 
considerably  beyond  the  others  in  the  same  manner,  but 
in  a  less  degree,  as  in  the  anthropomorphous  apes.  In 
these  cases,  open  spaces  between  the  teeth  in  the  one  jaw 
are  left  for  the  reception  of  the  canines  belonging  to  the 
opposite  jaw.    An  interspace  of  this  kind  in  a  Kaffir  skull, 

to  this  through  Prof.  Owen's  statement,  that  some  of  the  Ichthyopterygia 
possess  more  than  five  digits,  and  therefoi'e,  as  I  supposed,  had  retained 
a  primordial  condition;  but  after  reading  Prof.  Gegeubaur's  paper 
(' Jenaischen  Zeitschrift,'  B.  v.  Heft  3,  s.  341),  who  is  the  highest  author- 
ity in  Europe  on  such  a  point,  and  who  disputes  Owen's  conclusion,  I  see 
that  it  is  extremely  doubtful  whether  supernumerary  digits  can  thus  be 
accounted  foi".  It  was  the  fact  that  such  digits  not  only  frequently  occur 
and  are  strongly  inherited,  but  have  the  power  of  regrowth  after  amputa- 
tion, like  the  normal  digits  of  the  lower  vertebrata,  that  chiefly  led  me  to 
the  above  conclusion.  This  extraordinary  fact  of  their  regrowth  remains 
inexplicable,  if  the  beUef  in  reversion  to  some  extremely  remote  pro- 
genitor must  be  rejected.  I  cannot,  however,  foUov/^  Prof.  Gcgenbaur  in 
supposing  that  additional  digits  could  not  reappear  through  reversion, 
without  at  the  same  time  other  parts  of  the  skeleton  being  simultaneous- 
ly and  similarly  modified  ;  for  single  characters  often  reappear  through 
reversion. 

33  'Anatomy  of  Vertebrates,'  vol.  iii.  1868,  p.  323. 

*^  'Gencrclle  Morphologic,'  1866,  B.  ii.  s.  dv. 


122  THE  DESCENT   OF  MAX.  [Paht  I. 

figured  by  "Wagner,  is  surprisingly  wide/'  Considering 
how  few  ancient  skulls  have  been  examined  in  comparison 
with  recent  skulls,  it  is  an  interesting  fact  that  in  at  least 
three  cases  the  canines  project  largely ;  and  in  the  Nau- 
lettc  jaw  they  are  spoken  of  as  enormous." 

The  males  alone  of  the  anthropomorphous  aj^es  have 
their  canines  fully  developed ;  but  in  the  female  gorilla, 
and  in  a  less  degree  in  the  female  orang,  these  teeth  pro- 
ject considerably  beyond  the  others;  therefore  the  fact 
that  women  sometimes  have,  as  I  have  been  assured,  con- 
siderably projecting  canines,  is  no  serious  objection  to  the 
belief  that  their  occasional  great  development  in  man  is  a 
case  of  reversion  to  an  ape-like  progenitor.  He  who  rejects 
v.ith  scorn  the  belief  that  the  shape  of  his  own  canines, 
and  their  occasional  great  development  in  other  men,  are 
due  to  our  early  progenitors  having  been  provided  with 
these  formidable  Aveapons,  will  probably  reveal  by  sneer- 
ing the  line  of  his  descent.  For,  though  he  no  longer  in- 
tends, nor  has  the  power,  to  use  these  teeth  as  weapons, 
he  will  unconsciously  retract  his  "  snarling  muscles  "  (thus 
named  by  Sir  C.  Bell)"  so  as  to  expose  them  ready  for 
action,  like  a  dog  prepared  to  fight. 

Many  muscles  are  occasionally  developed  in  man, 
which  are  proper  to  the  Qnadrumaua  or  other  mammals. 
Professor  Vlacovich''*  examined  forty  male  subjects,  and 
found  a  muscle,  called  by  him  the  ischiopubic,  in  nineteen 
of  them ;  in  three  others  there  was  a  ligament  which 
represented  this  muscle;  and  in  the  remaining  eighteen 
no  trace  of  it.  Out  of  thirty  female  subjects  this  muscle 
was  developed  on  both  sides  in  only  two,  but  in  three 

*'  Carl  Vogt's  'Lectures  on  Man,'  Eng.  translat.  18G4,  p.  151. 
■"'-  C.  Carter  Blake,  on  a  jaw  from  La  Naulctte,  'Anthropolog.  Review,' 
1S6V,  p.  295.     Schaaffhauscn,  ibid.  18G8,  p.  42G. 

43  'The  Anatomy  of  Expression,'  1844,  pp.  110,  131. 

^*  Quoted  by  Prof  Canc?trini  in  the  'Annuario,'  etc.,  1867,  p.  00. 


Chap,  IV.]  MANNER  OF  DEVELOPMENT.  123 

others  the  ruclimeutaiy  ligament  Avas  present.  This 
muscle,  therefore,  appears  to  be  much  more  common  in 
the  male  than  in  the  female  sex ;  and  on  the  jDrinciple  of 
the  descent  of  man  from  some  lower  form,  its  presence  can 
be  understood ;  for,  it  has  been  detected  in  several  of  the 
lower  animals,  and  in  all  of  these  it  serves  exclusively  to 
aid  the  male  in  the  act  of  reproduction. 

Mr.  J.  Wood,  in  his  valuable  series  of  papers,"  has 
minutely  described  a  vast  number  of  muscular  variations 
in  man,  which  resemble  normal  structures  in  the  loAver 
animals.  Looking  only  to  the  muscles  which  closely  re- 
semble those  regularly  present  in  our  nearest  allies,  the 
Quadrumana,  they  are  too  numerous  to  be  here  even 
specified.  In  a  single  male  subject,  having  a  strong  bodily 
frame  and  well-formed  skull,  no  less  than  seven  muscular 
variations  were  observed,  all  of  which  plainly  represented 
muscles  proper  to  various  kinds  of  apes.  This  man,  for 
instance,  had  on  both  sides  of  his  neck  a  true  and  power- 
ful '•'■levator  claviculm^''  such  as  is  foUnd  in  all  kinds  of 
apes,  and  which  is  said  to  occur  in  about  one  out  of  sixty 
human  subjects."  Again,  this  man  had  "a  special  ab- 
ductor of  the  metatarsal  bone  of  the  fifth  digit,  such 
as  Prof.  Huxley  and  Mr.  Flower  have  shown  to  exist 
uniformly  in  the  higher  and  lower  apes."     The  hands  and 

••^  These  papers  deserve  careful  study  by  any  one  who  desires  to  learn 
how  frequently  our  muscles  vary,  and  in  varying  come  to  resemble  those 
of  the  Quadrumana.  The  following  references  relate  to  the  few  points 
touched  on  in  my  text :  vol.  xiv.  1865,  pp.  3'79-384 ;  vol.  xv.  1866,  pp.  2-11, 
242 ;  vol.  XV.  1867,  p.  644 ;  vol.  xvi.  1868,  p.  524.  I  may  here  add  that 
Dr.  Murie  and  Mr.  St.  George  Mivart  have  shown  in  their  Memoir  on  the 
Lemuroidea  ('Transact.  Zoolog.  Soc'  vol.  vii.  1869,  p.  96),  how  extraor- 
dinarily variable  some  of  the  muscles  are  in  these  animals,  the  lowest 
members  of  the  Primates.  Gradations,  also,  in  the  muscles  leading  to 
structures  found  in  animals  still  lower  in  the  scale,  are  numerous  in  the 
Lemuroidea. 

*5  Prof.  Macalister  in  'Froc.  P.  Irish  Academy,'  vol.  x.  1868,  p.  124, 


124  TDE   DESCENT   OF  MAN.  [Part  I. 

arms  of  man  are  eminently  characteristic  structures,  but 
their  muscles  are  extremely  liable  to  vary,  so  as  to  re- 
semble the  cori'esponding  muscles  in  the  lower  animals." 
Such  resemblances  are  either  complete  and  perfect  or  im- 
perfect, yet  in  this  latter  case  manifestly  of  a  transitional 
nature.  Certain  variations  arc  more  common  in  man,  and 
others  in  -woman,  without  our  being  able  to  assign  any 
reason.  Mr.  Wood,  after  describing  numerous  cases, 
makes  the  following  pregnant  remark  :  "  Notable  depart- 
ures from  the  ordinary  type  of  the  muscular  structures 
run  in  grooves  or  directions,  which  must  be  taken  to  in- 
dicate some  unknown  factor,  of  much  importance  to  a  com- 
prehensive knowledge  of  general  and  scientific  anatomy."" 
That  this  unknown  factor  is  reversion  to  a  former 
state  of  existence  may  be  admitted  as  in  the  highest  de- 
gree probable.  It  is  quite  incredible  that  a  man  should 
through  mere  accident  abnoiTually  resemble,  in  no  less 
than  seven  of  his  muscles,  certain  apes,  if  there  had  been 
no  genetic  connection  between  them.  On  the  other  hand, 
if  man  is  descended  from  some  ape-like  creature,  no  valid 
reason  can  be  assigned  why  certain  muscles  should  not 

*''  Prof.  Macalister  (ibid.  p.  121)  has  tabulated  his  observations,  and 
finds  that  muscular  abnoriaalitics  are  most  frequent  in  the  forearms, 
secondly  in  the  face,  thirdly  in  the  foot,  etc. 

^s  The  Rev.  Dr.  Haughton,  after  giving  ('  Proc.  R.  Irish  Academy,' 
June  27,  1861,  p.  715)  a  remarkable  case  of  variation  in  the  human 
Jlcxor  pollicis  lonr/2is,  adds :  "  This  remarkable  example  shows  that  man 
may  sometimes  possess  the  arrangement  of  tendons  of  thumb  and  lingers 
characteristic  of  the  macaque ;  but  whether  such  a  case  should  be  re- 
garded as  a  macaque  passing  upward  into  a  man,  or  a  man  passing 
downward  into  a  macaque,  or  as  a  congenital  freak  of  Nature,  I  cannot 
undertake  to  say."  It  is  satisfactory  to  he.ir  so  capable  an  anatomist, 
and  so  embittered  an  opponent  of  evolutionism,  admitting  even  the  pos- 
t-ibility  of  either  of  his  first  propositions.  Prof.  Macalister  has  also  de- 
scribed ('Proc.  R.  Irish  Acad.'  vol.  x.  18G1,  p.  138)  variations  in  the 
ficxor  poUicis  longus,  remarkable  from  their  relations  to  the  same  muscle 
in  the  Quadiuniaua. 


CnAP.  lY.]  MANNER  OF  DEVELOPMENT.  ]25 

suddenly  reappear  after  an  interval  of  many  thousand 
generations,  in  the  same  manner  as  with  horses,  asses,  and 
mules,  dark-colored  stripes  suddenly  reappear  on  the  legs 
and  shoulders,  after  an  interval  of  hundreds,  or  more  prob- 
ably thousands,  of  generations. 

These  various  cases  of  reversion  are  so  closely  related 
to  those  of  rudimentary  organs  given  in  the  first  chapter, 
that  many  of  them  might  have  been  indifferently  intro- 
duced in  either  chapter.  Thus  a  human  uterus  furnished 
with  cornita  may  be  said  to  represent  in  a  rudimentary 
condition  the  same  organ  in  its  normal  state  in  certain 
mammals.  Some  parts  which  are  rudimental  in  man,  as 
the  OS  coccyx  in  both  sexes  and  the  mammoe  in  the  male 
sex,  are  always  present ;  while  others,  such  as  the  supra- 
condyloid  foramen,  only  occasionally  appear,  and  there- 
fore might  have  been  introduced  under  the  head  of  rever- 
sion. These  several  reversionary,  as  well  as  the  strictly 
rudimentary,  structures  reveal  the  descent  of  man  from 
some  lower  form  in  an  unmistakable  manner. 

Correlated  Variation. — In  man,  as  in  the  lower  ani- 
mals, many  structures  are  so  intimately  related,  that  when 
one  part  varies  so  does  another,  without  our  being  able, 
in  most  cases,  to  assign  any  reason.  We  cannot  say 
whether  the  one  part  governs  the  "other,  or  whether  both 
are  governed  by  some  earlier  developed  part.  Various 
monstrosities,  as  I.  Geoffroy  repeatedly  insists,  are  thus 
intimately  connected.  Homologous  structures  are  par- 
ticularly liable  to  change  together,  as  we  see  on  the  op- 
posite sides  of  the  body,  and  in  the  upper  and  lower  ex- 
tremities. Meckel  long  ago  remarked  that  when  the 
muscles  of  the  arm  depart  from  their  proper  type,  they 
almost  al'.vays  imitate  those  of  the  leg ;  and  so  conversely 
with  the  muscles  of  the  legs.  The  organs  of  sight  and 
hearing,  the  teeth  and  hair,  the  color  of  the  skin  and 


126  THE  DESCKNT  OF   MAX.  [Part  1. 

liair,  color  and  constitution,  arc  more  or  less  correlated." 
Prof.  Schaaffliausen  first  drew  attention  to  the  relation 
apparently  existing  between  a  muscular  frame  and  strong- 
ly-pronounced supra-orbital  ridges,  which  are  so  char- 
acteristic of  the  lower  races  of  man. 

Besides  the  variations  which  can  be  grouped  with  more 
or  less  probability  under  the  foregoing  heads,  there  is 
a  large  class  of  variations  which  may  be  provisionally 
callsd  spontaneous,  for  they  appear,  owing  to  our  igno- 
rance, to  arise  without  any  exciting  caiise.  It  can,  how- 
ever, be  shown  that  such  variations,  whether  consisting 
of  sliglit  individual  differences,  or  of  strongly-marked 
and  abrupt  deviations  of  structure,  deiDcnd  much  more 
on  the  constitution  of  the  organism  than  on  the  nature 
of  the  conditions  to  which  it  has  been  subjected.'" 

Mate  of  Increase. — Civilized  populations  have  been 
known  under  favorable  conditions,  as  in  the  United  States, 
to  double  their  number  in  tAventy-five  years;  and,  ac- 
cording to  a  calculation  by  Euler,  this  might  occur  in  a 
little  over  twelve  years."  At  the  former  rate  the  present 
population  of  the  United  States,  namely,  thirty  millions, 
would  in  657  years  cover  the  whole  terraqueous  globe  so 
thickly,  that  four  men  would  have  to  stand  on  each  square 
yard  of  surface.  The  primary  or  fundamental  check  to 
the  continued  increase  of  man  is  the  difficulty  of  gaining 
subsistence  and  of  living  in  comfort.  Yv"c  may  infer  that 
this  is  the  case  from  what  we  see,  for  instance,  in  the 
United  States,  where  subsistence   is  easy  and   there   is 

■*'  The  authorities  for  these  several  statements  are  given  in  my 
'  Variation  of  Animals  under  Domestication,'  vol.  ii.  pp.  320-335. 

''*'  Tiiis  whole  subject  has  been  discussed  in  chap,  xxiii.  vol.  ii.  of  my 
'  Variation  of  Animals  and  Plants  under  Domestication.' 

^'  See  the  ever-memorable  '  Essay  on  the  Principle  of  Population,' 
by  the  Rev.  T.  Malthus,  vol.  i.  1825,  pp.  6,  517. 


CflAr.  IV.]  MANNER  OF  DEVELOPMENT.  127 

plenty  of  room.  If  siicli  means  were  suddenly  doubled 
in  Great  Britain,  our  number  would  be  quickly  doubled. 
With  civilized  nations  tlie  above  primary  check  acts 
chiefly  by  restraining  marriages.  The  greater  death-rate 
of  infants  in  the  poorest  classes  is  also  very  important ; 
as  well  as  the  greater  mortality  at  all  ages,  and  from 
various  diseases,  of  the  inhabitants  of  crowded  and  mis- 
erable houses.  The  effects  of  severe  epidemics  and  wars 
are  soon  counterbalanced,  and  more  than  counterbalanced, 
in  nations  placed  under  favorable  conditions.  Emigration 
also  comes  in  aid  as  a  temporary  check,  but  not  to  any 
great  extent  with  the  extremely  poor  classes. 

There  is  reason  to  suspect,  as  Malthus  has  remarked, 
that  the  reproductive  power  is  actually  less  in  barbarous 
than  in  civilized  races.  We  know  notliing  positively  on 
this  head,  for  with  savages  no  census  has  been  taken; 
but  from  the  concurrent  testimony  of  missionaries,  and 
of  others  who  have  long  resided  with  such  peoj)le,  it  ap- 
^  -^ars  that  their  families  are  usually  small,  and  large  ones 
rare.  This  may  be  partly  accounted  for,  as  it  is  believed, 
by  the  -^omen  suckling  their  infants  for  a  prolonged 
period ;  but  it  is  highly  probable  that  savages,  who  often 
suffer  much  hardship,  and  who  do  not  obtain  so  much  nu- 
tritious food  as  civilized  men,  would  be  actually  less  pro- 
lific. I  have  shown  in  a  former  work,  "  that  all  our  do- 
mesticated quadrupeds  and  birds,  and  all  our  cultivated 
plants,  are  more  fertile  than  the  corresponding  species  in 
a  state  of  nature.  It  is  no  valid  objection  to  this  con- 
clusion that  animals  suddenly  supplied  with  an  excess  of 
food,  or  when  rendered  very  fat,  and  that  most  plants 
when  suddenly  removed  from  very  poor  to  very  rich  soil, 
are  rendered  more  or  less  sterile.  We  might,  therefore, 
expect  that  civilized  men,  who  in  one  sense  are  highly  do- 

^'^  'Variation  of  Animals  and  Plants  under  Domes  tic.ition,'  vol.  ii  pp. 
111-113,  163. 


128  THE  DESCENT  OF  MAX.  [Part  I. 

mesticated,  would  be  more  proliiic  than  wild  men.  It  is 
also  probable  that  the  increased  fertility  of  civilized  na- 
tions would  become,  as  with  our  domestic  animals,  an  in- 
herited character :  it  is  at  least  known  that  with  mankind 
a  tendency  to  produce  twins  runs  in  families." 

Kotwithstanding  that  savages  appear  to  be  less  pro- 
lific than  civilized  people,  they  would  no  doubt  rapidly  in- 
crease if  their  numbers  wex'C  not  by  some  means  rigidly 
kept  down.  The  Santali,  or  hill-tribes  of  India,  have 
recently  afforded  a  good  illustration  of  this  fact ;  for  they 
have  increased,  as  shown  by  3Ir.  Hunter,"  at  an  extraor- 
dinary rate  since  vaccination  has  been  introduced,  other 
pestilences  mitigated,  and  war  sternly  repressed.  This 
increase,  however,  would  not  have  been  possible  had  not 
these  rude  people  spread  into  the  adjoining  districts  and 
worked  for  hire.  Savages  almost  always  marry;  yet 
there  is  some  prudential  restraint,  for  they  do  not  com- 
monly marry  at  the  earliest  possible  age.  The  young 
men  are  often  required  to  show  that  they  can  support  a 
wife,  and  they  generally  have  fii'st  to  earn  the  price  with 
which  to  purchase  her  from  her  parents.  AYith  savages 
the  difficulty  of  obtaining  subsistence  occasionally  limits 
their  number  in  a  much  more  direct  manner  than  with 
civilized  people,  for  all  tribes  periodically  suffer  from  se- 
vere famines.  At  such  times  savages  are  forced  to  devour 
much  bad  food,  and  their  health  can  hardly  fail  to  be  in- 
jured. Many  accounts  have  been  published  of  their  pro- 
truding stomachs  and  emaciated  lunbs  after  and  during' 
famines.  They  are  then,  also,  compelled  to  wander  much 
about,  and  their  infants,  as  I  was  assured  in  Australia, 
perish  in  large  numbers.  As  famines  are  periodical,  de- 
jicnding  chiefly  on  extreme  seasons,  all  tribes  must  fluc- 

'5  Mr.  Sedgwick,  'British  and  Foreign  Mcdico-Cliirurg.  Kcvicw,'  July, 
1S63,  p.  110. 

"  'The  Annals  of  Kural  Bengal,'  by  W.  W.  Hunter,  ISCS,  p.  259. 


Chap.  IV.]  MANNER   OF  DEVELOPMENT.  129 

tuate  in  number.  They  cannot  steadily  and  regularly  in- 
crease, as  there  is  no  artificial  increase  in  the  supply  of 
food.  Savages  when  hardly  pressed  encroach  on  each 
other's  territories,  and  war  is  the  result ;  but  they  are  in- 
deed almost  always  at  war  with  their  neighbors.  They 
are  liable  to  many  accidents  on  land  and  water  in  their 
search  for  food ;  and  in  some  countries  they  must  suffer 
much  from  the  larger  beasts  of  prey.  Even  in  India,  dis- 
tricts have  been  depopulated  by  the  ravages  of  tigers. 

Malthus  has  discussed  these  several  checks,  but  he 
does  not  lay  stress  enough  on  what  is  probably  the  most 
important  of  all,  namely  infanticide,  especially  of  female 
infants,  and  the  habit  of  procuring  abortion.  These  prac- 
tices now  prevail  in  many  quarters  of  the  world,  and  in- 
fanticide seems  formerly  to  have  prevailed,  as  Mr.  M'Len- 
nan  "  has  shown,  on  a  still  more  extensive  scale.  These 
practices  appear  to  have  originated  in  savages  recognizing 
the  difficulty,  or  rather  the  impossibility,  of  supporting  all 
the  infants  that  are  born.  Licentiousness  may  also  be 
added  to  the  foregoing  checks  ;  but  this  does  not  follow 
from  failing  means  of  subsistence  ;  though  there  is  reason 
to  believe  that  in  some  cases  (as  in  Japan)  it  has  been  in- 
tentionally encouraged  as  a  means  of  keeping  down  the 
population. 

If  we  look  back  to  an  extremely  remote  epoch,  before 
man  had  arrived  at  the  dignity  of  manhood,  he  would 
have  been  guided  more  by  instinct  and  less  by  reason 
than  are  savages  at  the  present  time.  Our  early  semi- 
human  progenitors  would  not  have  practised  infanticide, 
for  the  instincts  of  the  lower  animals  are  never  so  per- 
verted as  to  lead  them  regularly  to  destroy  their  own  off- 
tspring.  There  would  have  been  no  prudential  restraint 
from  marriage,  and  the  sexes  would  have  freely  united  at 
an  early  age.     Hence  the  progenitors  of  man  would  have 

"  '  rrimitivc  Marriage,'  1865. 


130  THE   DESCENT   OF   MAX.  [Part  I. 

tended  to  increase  rapidly,  but  checks  of  some  kind,  either 
periodical  or  constant,  must  have  kept  down  their  num- 
bers, even  more  severely  than  with  existing  savages. 
"What  the  precise  nature  of  these  checks  may  have  been, 
we  cannot  say,  any  more  than  with  most  other  animals. 
We  know  that  horses  and  cattle,  which  ai-e  not  highly 
prolific  animals,  when  first  turned  loose  in  South  America, 
increased  at  an  enormous  rate.  The  slowest  breeder  of 
all  known  animals,  namely  the  elephant,  would  in  a  few 
thousand  years  stock  the  whole  world.  The  increase  of 
every  species  of  monkey  must  be  checked  by  some  means ; 
but  not,  as  Brehm  remarks,  by  the  attacks  of  beasts  of 
prey.  No  one  will  assume  that  the  actual  power  of  re- 
production in  the  wild  horses  and  cattle  of  America  was 
at  first  in  any  sensible  degree  increased  ;  or  that,  as  each 
district  became  fully  stocked,  this  same  power  was  dimin- 
ished. No  doubt  in  this  case,  and  in  all  others,  many 
checks  concur,  and  diflferent  checks  under  different  circum- 
stances ;  periodical  dearths,  depending  on  unfavorable 
seasons,  being  probably  the  most  important  of  all.  So  it 
Avill  have  been  with  the  eai'ly  progenitors  of  man. 

JSFatifral  Selection. — We  have  now  seen  that  man  is 
variable  in  body  and  mind ;  and  that  the  variations  are 
induced,  either  directly  or  indirectly,  by  the  same  general 
causes,  and  obey  the  same  general  laws,  as  with  the  lower 
animals.  Man  has  spread  widely  over  the  face  of  the 
earth,  and  must  have  been  exposed,  dui-ing  his  incessant 
migi-ations,''  to  the  most  diversified  conditions.  The  in- 
habitants of  Tierra  del  Fuego,  the  Cape  of  Good  Hope, 
and  Tasmania  in  the  one  hemisphere,  and  of  the  Arctic 
regions  in  the  other,  must  have  jiassed  through  many  cli- 
mates and  changed  tlieir  habits  many  times,  before  they 

**  See  some  good  remarks  to  this  effect  by  W.  Stanley  Jcvons,  "  A 
Deduction  from  Darwin's  Tiieory,"  'Xature,'  1860,  p.  231. 


Chap.  IV.]  MANxYER   OF  DEVELOPMENT.  ]31 

reached  their  present  homes."  The  early  progenitors  of 
man  miist  also  have  tended,  like  all  other  animals,  to  have 
increased  beyond  their  means  of  subsistence ;  they  must 
therefore  occasionally  have  been  exposed  to  a  struggle  for 
existence,  and  consequently  to  the  rigid  law  of  natural 
selection.  Beneficial  variations  of  all  kinds  will  thus, 
either  occasionally  or  habitually,  l\;ive  been  preserved,  and 
injurious  ones  eliminated.  I  do  not  refer  to  strongly- 
marked  deviations  of  structure,  which  occur  only  at  long- 
intervals  of  time,  but  to  mere  individual  diiferences.  We 
know,  for  instance,  that  the  muscles  of  our  hands  and  feet, 
which  determine  our  powers  of  movement,  are  liable,  like 
those  of  the  lower  animals,^®  to  incessant  variability.  If, 
then,  the  ape-like  progenitors  of  man  which  inhabited  any 
district,  esiDCcially  one  undergoing  some  change  in  its  con- 
ditions, were  divided  into  two  equal  bodies,  the  one  half 
which  included  all  the  individuals  best  adapted  by  their 
powers  of  movement  for  gaining  subsistence  or  for  defend- 
ing themselves,  would  on  an  average  survive  in  greater 
niimber  and  procreate  more  oiFspring  than  the  other  and 
less  well-endowed  half. 

Man  in  the  rudest  state  in  which  he  now  exists  is  the 
most  dominant  animal  that  has  ever  appeared  on  the  earth. 
He  has  spread  more  widely  than  any  other  highly-organ- 
ized form ;  and  all  others  have  yielded  before  him.  He 
manifestly  owes  this  immense  superiority  to  his  intellectual 
faculties,  his  social  habits,  which  lead  him  to  aid  and  de- 
fend his  fellows,  and  to  his  corporeal  structure.  The 
suj^reme  importance  of  these  characters  has  been  j)i-oved 

'■'  Latham,  'Man  and  his  Migrations,'  1851,  p.  135. 

^5  Messrs.  Murie  and  Mivart,  in  their  "  Anatomy  of  the  Lemuroidea  " 
('Transact.  Zoolog.  Soc'  vol.  vii.  1869,  pp.  96-98)  say,  "  some  muscles  are 
so  irregular  in  their  distribution  that  they  cannot  be  well  classed  in  any 
of  the  above  groups."  These  muscles  differ  even  on  the  opposite  sides 
of  the  same  individual. 


132  THE  DESCENT   OF  MAN.  [Part  I. 

by  tlie  final  arbitrament  of  the  battle  for  life.  Through 
his  poAvers  of  intellect,  articulate  language  has  been 
evolved;  and  on  this  his  wonderful  advancement  has 
mainly  dej^cnded.  lie  has  invented  and  is  able  to  use 
various  weapons,  tools,  traps,  etc.,  with  which  he  defends 
liimself,  kills  or  catches  ]}rcj,  and  otherwise  obtains  food, 
lie  has  made  rafts  or  canoes  on  whicli  to  fish  or  cross  over 
to  neighboring  fertile  islands.  He  has  discovered  the  art 
of  making  fire,  by  which  hard  and  stringy  roots  can  be 
rendered  digestible,  and  poisonous  roots  or  herbs  innocu- 
ous. This  last  discovery,  probably  the  greatest,  excepting 
language,  ever  made  by  man,  dates  from  before  the  dawn 
of  history.  These  several  inventions,  by  which  man  in  the 
rudest  state  has  become  so  preeminent,  are  the  direct  re- 
sult of  the  development  of  his  powers  of  observation, 
memory,  curiosity,  imagination,  and  reason.  I  cannot, 
therefore,  understand  how  it  is  that  Mr.  "Wallace  "  main- 
tains, that  "natural  selection  could  only  have  endowed 
the  savage  v/ith  a  brain  a  little  superior  to  that  of  an 
ape." 

Although  the  intellectual  powers  and  social  habits  of 

'^'Quarterly  Review,'  April,  1869,  p.  392.  This  subject  is  more 
fully  discussed  in  Mr.  Wallace's  '  Contributions  to  the  Theory  of  Natural 
Selection,'  ISYO,  in  which  all  the  essays  referred  to  in  this  work  are  re- 
published. The  'Essay  on  Man '  has  been  ably  criticised  by  Pi'of  Clapa- 
rede,  one  of  the  most  distinguished  zoologists  in  Europe,  in  an  article 
published  in  the  '  Bibliothcque  Universelle,'  June,  1870.  The  remark 
quoted  in  my  text  will  surprise  every  one  who  has  read  Mr.  Wallace's 
celebrated  paper  on  '  The  Origin  of  Human  Races  deduced  from  the 
Theory  of  Natural  Selection,'  originally  published  in  the  '  Anthropologi- 
cal Review,'  May,  1864,  p.  clviiL  I  cannot  here  resist  quoting  a  most 
just  remark  by  Sir  J.  Lubbock  (' Prehistoric  Times,'  1865,  p.  479)  in 
reference  to  this  paper,  namely,  that  Mr.  Wallace,  "  with  characteristic 
imsclfishness,  ascribes  it  (i  e.,  the  idea  of  natural  selection)  unreservedly 
to  Mr.  Darwin,  although,  as  is  well  known,  he  struck  out  the  idea  inde- 
pendently, and  published  it,  though  not  with  the  same  elaboration,  at  the 
same  time." 


Chap.  IV.]  MANNER   OF   DEVELOPMENT.  133 

man  are  of  paramount  importance  to  him,  we  must  not 
underrate  the  importance  of  his  bodily  structure,  to  whicli 
subject  tlie  remainder  of  this  chapter  will  be  devoted. 
The  development  of  the  intellectual  and  social  or  moral 
faculties  will  be  discussed  in  the  following  chapter. 

Even  to  hammer  with  precision  is  no  easy  matter,  as 
every  one  who  has  tried  to  leam  car^^entry  will  admit. 
To  throw  a  stone  with  as  true  an  aim  as  can  a  Fuegian  in 
defending  himself,  or  in  killing  birds,  requires  the  most 
consummate  perfection  in  the  correlated  action  of  the 
muscles  of  the  hand,  ai-m,  and  shoulder,  not  to  mention  a 
fine  sense  of  touch.  In  throwing  a  stone  or  spear,  and  in 
many  other  actions,  a  man  must  stand  firmly  on  his  feet ; 
and  this  again  demands  the  perfect  coadaptation  of  nu- 
merous muscles.  To  chip  a  flint  into  the  rudest  tool,  or 
to  form  a  barbed  spear  or  hook  from  a  bone,  demands  the 
use  of  a  perfect  hand ;  for,  as  a  most  capable  judge,  Mr. 
Schoolcraft,""  remarks,  the  shaping  fragments  of  stone  into 
knives,  lances,  or  arrow-heads,  shows  "  extraordinary  abil- 
ity and  long  practice."  We  have  evidence  of  this  in 
primeval  men  having  practised  a  division  of  labor ;  each 
man  did  not  manufacture  his  own  flint  tools  or  rude  pot- 
tery ;  but  certain  individuals  appear  to  have  devoted 
themselves  to  such  work,  no  doubt  receiving  in  exchange 
the  produce  of  the  chase.  Archaiologists  are  convinced 
that  an  enormous  interval  of  time  elapsed  before  our  an- 
cestors thought  of  grinding  chipped  flints  into  smooth 
tools.  A  man-like  animal  who  jjossessed  a  hand  and  arm 
sufticiently  perfect  to  throw  a  stone  with  precision  or  to 
form  a  flint  into  a  rude  tool,  could,  it  can  hardly  be  doubt- 
ed, with  sufiicient  practice  make  almost  any  thing,  as  far 
as  mechanical  skill  alone  is  concerned,  which  a  civilized 

™  Quoted  by  Mr.  Lawson  Tait  in  his  "Law  of  Natural  Selection" — 
'Dublin  Quarterly  Journal  of  Medical  Science,'  Feb.  1869.  Dr.  Keller  is 
likewise  quoted  to  the  same  effect. 


134  THE   DESCENT   OF  MAN.  [Part  I. 

man  can  uiakc.  The  structure  of  the  hand  in  this  respect 
may  be  compared  "with  that  of  the  vocal  organs,  whicli  in 
the  apes  are  used  for  uttering  various  signal-cries,  or,  as  in 
one  species,  musical  cadences  ;  but  in  man  closely  similar 
vocal  organs  have  become  adapted  through  the  inherited 
effects  of  use  for  the  utterance  of  articulate  language. 

Turnmg  now  to  the  nearest  allies  of  man,  and  there- 
fore to  the  best  representatives  of  our  early  progenitoi's, 
we  find  that  the  hands  in  the  Quadrumana  are  constructed 
on  the  same  general  pattern  as  in  us,  but  are  far  less  per- 
fectly adapted  for  diversified  uses.  Their  hands  do  not 
serve  so  well  as  the  feet  of  a  dog  for  locomotion  ;  as  may 
be  seen  in  those  monkeys  which  walk  on  the  outer  mar- 
gins of  the  palms,  or  on  the  backs  of  tlieir  bent  fingers, 
as  in  the  chimpanzee  and  orang."  Their  hands,  however, 
are  admirably  adaj^ted  for  climbing  trees.  Monkeys  seize 
thin  branches  or  ropes,  with  the  thumb  on  one  side  and 
the  fingers  and  palm  on  the  other  side,  in  tlie  same  manner 
as  we  do.  They  can  thus  also  carry  rather  large  objects, 
such  as  the  neck  of  a  bottle,  to  their  mouths.  Baboons 
turn  over  stones  and  scratch  up  roots  with  their  hands. 
They  seize  nuts,  insects,  or  other  small  objects,  with  the 
thumb  in  opposition  to  the  fingers,  and  no  doubt  they 
thus  extract  eggs  and  the  young  from  the  nests  of  birds. 
American  monkeys  beat  the  wild  oranges  on  the  branches 
until  the  rind  is  cracked,  and  then  tear  it  off  with  the  fin- 
gers of  the  two  hands.  Other  monkeys  open  mussel-shells 
with  the  two  thumbs.  With  their  fingers  they  pull  out 
tlioi-ns  and  burs,  and  hunt  for  each  other's  parasites.  In 
a  state  of  Nature  they  break  open  hard  fruits  with  the  aid 
of  stones.  They  roll  down  stones  or  throw  them  at  their 
enemies  ;  nevertheless,  they  perform  these  various  actions 
clumsily,  and  they  arc  quite  unable,  as  I  have  myself  seen, 
to  throw  a  stone  with  precision. 

*'  Owen,  'Anatomy  of  Vertebrates,'  vol.  iii.  p.  Tl. 


CiiAP.  IV.]  MANNER   OF  DEVELOPMENT.  135 

It  seems  to  me  far  from  true  that  because  "  objects  are 
grasped  clumsily  "  by  monkeys,  "  a  much  less  specialized 
organ  of  prehension"  would  have  served  them'"  as  well 
as  their  present  hands.  On  the  contrarj^,  I  see  no  reason 
to  doubt  that  a  more  perfectly  constructed  hand  would 
have  been  an  advantage  to  them,  provided,  and  it  is  im- 
portant to  note  this,  that  their  hands  had  not  thus  been 
rendered  less  well  adapted  for  climbmg  trees.  We  may 
suspect  that  a  perfect  hand  would  have  been  disadvanta- 
geous for  clunbing;  as  the  most  arboreal  monkeys  in 
the  world,  namely  Ateles  in  America  and  Hylobates  in 
Asia,  either  have  their  thumbs  much  reduced  in  size 
and  even  rudimentary,  or  their  fingers  partially  coherent, 
so  that  their  hands  are  converted  into  mere  graspino-- 
hooks.'^' 

As  soon  as  some  ancient  member  in  the  great  series  of 
the  Primates  came,  owing  to  a  change  in  its  manner  of 
procuring  subsistence,  or  to  a  change  in  the  conditions 
of  its  native  country,  to  live  somewhat  less  on  trees  and 
more  on  the  ground,  its  manner  of  progression  would  have 
been  modified  ;  and  in  this  case  it  would  have  had  to  be- 
come either  more  strictly  quadrupedal  or  bipedal.  Ba- 
boons frequent  hilly  and  rocky  districts,  and  only  from 
necessity  climb  up  high  trees;'*  and  they  have  acquired 
almost  the  gait  of  a  dog.  Man  alone  has  become  a  biped ; 
and  we  can,  I  think,  partly  see  how  he  has  come  to  assume 
his  erect  attitude,  which  forms  one  of  the  most  conspicu- 
ous diflerences  between  him  and  his  nearest  allies.  Man 
could  not  have  attained  his  present  dominant  position  in 
the  world  without  the  use  of  his  hands,  which  are  so  ad- 

*2  'Quarterly  Review,'  April,  1869,  p.  892. 

^3  In  Hylobates  syndadylus,  as  the  name  expresses,  two  of  the  digits 
regularly  cohere  ;  and  this,  as  Mr.  Blyth  informs  me,  is  occasionally  the 
case  with  the  digits  of  H.  agilis,  Jar,  and  huciscus. 

"  Brehm,  '  Thicrleben,'  B.  i.  s.  80. 


136  TnE   DESCENT   OF   MAN.  [Part  I. 

mirably  adapted  to  act  in  obedience  to  liis  will.  As  Sir 
C.  Bell "''  insists,  "  the  hand  supplies  all  instruments,  and 
by  its  correspondence  with  the  intellect  gives  liim  univer- 
sal dominion."  But  the  hands  and  arms  could  hardly 
have  become  perfect  enough  to  have  manufactured  weap- 
ons, or  to  have  hurled  stones  and  spears  Avith  a  true  aim,  as 
long  as  they  were  habitually  used  for  locomotion  and  for 
supporting  the  whole  weight  of  the  body,  or  as  long  as 
they  were  especially  well  adapted,  as  previously  remarked, 
for  climbing  trees.  Such  rough  treatment  would  also  have 
blunted  the  sense  of  touch,  on  which  their  delicate  use 
largely  depends.  From  these  causes  alone  it  would  have 
been  an  advantage  to  man  to  have  become  a  biped  ;  but 
for  many  actions  it  is  almost  necessary  that  both  arms  and 
the  whole  upper  part  of  the  body  should  be  free  ;  and  he 
must  for  this  end  stand  firmly  on  his  feet.  To  gain  this 
great  advantage,  the  feet  have  been  rendered  flat,  and  the 
great-toe  peculiarly  modified,  though  this  has  entailed  the 
loss  of  the  power  of  prehension.  It  accords  with  the  prin- 
ciple of  the  division  of  physiological  labor,  which  prevails 
throughout  the  animal  kingdom,  that,  as  the  hands  became 
perfected  for  prehension,  the  feet  should  have  become  per- 
fected for  support  and  locomotion.  With  some  savages, 
however,  the  foot  has  not  altogether  lost  its  prehensile 
power,  as  shown  by  their  manner  of  climbing  trees  and 
of  using  them  in  other  ways."" 

If  it  be  an  advantage  to  man  to  have  his  hands  and 

""The  Hand,  its  Mechanism,"  etc.  'Bridgewater  Treatise,'  1833, 
p.  38. 

*'  Hiickel  has  an  excellent  discussion  on  the  steps  by  which  man  be- 
came a  biped:  'Natiirliche  Schiipfungsgeschichte,'  1SC8,  s.  507.  Dr. 
Biichner  ('Conferences  sur  la  Thoorie  Darwinienne,'  1869,  p.  135)  has 
given  good  cases  of  tlic  use  of  the  foot  as  a  prehensile  organ  by  man  ; 
also  on  the  manner  of  progression  of  the  higher  apes  to  which  I  allude 
in  the  following  paragraph :  see  also  Owen  ('Anatomy  of  Vertebrates,' 
vol.  iii.  p.  71)  on  this  latter  subject. 


Chap.  IV.]  MANNER   OF  DEVELOPMENT.  137 

arms  free  and  to  stand  firmly  on  his  feet,  of  wLicli  there 
can  be  no  doubt  from  his  preeminent  success  in  the  battle 
of  life,  then  I  can  see  no  reason  why  it  should  not  have 
been  advantageous  to  the  progenitors  of  man  to  have  be- 
come more  and  more  erect  or  bipedal.  They  would, thus 
have  been  better  able  to  have  defended  themselves  with 
stones  or  clubs,  or  to  have  attacked  their  prey,  or  other- 
wise obtained  food.  The  best-constructed  individuals 
would  in  the  long-run  have  succeeded  best,  and  have  sur- 
vived in  larger  numbers.  If  the  gorilla  and  a  few  allied 
forms  had  become  extinct,  it  might  have  been  argued  with 
great  force  and  apparent  truth,  that  an  animal  could  not 
have  been  gradually  converted  from  a  quadruped  into  a 
biped ;  as  all  the  individuals  in  an  intermediate  condition 
would  have  been  miserably  ill-fitted  for  progression.  But 
we  know  (and  this  is  well  worthy  of  reflection)  that  sev- 
eral kinds  of  apes  are  now  actually  in  this  intermediate 
condition ;  and  no  ojie  doubts  that  they  are  on  the  whole 
v/ell  adapted  for  their  conditions  of  life.  Thus  the  gorilla 
runs  with  a  sidelong  shambling  gait,  but  more  commonly 
progresses  by  resting  on  its  bent  hands.  The  long-armed 
apes  occasionally  use  their  arms  like  crutches,  swinging 
their  bodies  forward  between  them,  and  some  kinds  of 
Hylobates,  without  having  been  taught,  can  walk  or  run 
upright  with  tolerable  quickness  ;  yet  they  move  awk- 
wardly, and  much  less  securely  than  man.  We  see,  in 
short,  with  existing  monkeys  various  gradations  between 
a  form  of  progression  strictly  like  that  of  a  quadruped 
and  that  of  a  biped  or  man. 

As  the  progenitors  of  man  became  more  and  more 
erect,  with  their  hands  and  arms  more  and  more  modified 
for  prehension  and  other  purposes,  with  their  feet  and  legs 
at  the  same  time  modified  for  firm  support  and  progi*es- 
sion,  endless  other  changes  of  structure  would  have  been 
necessary.    The  pelvis  would  have  had  to  be  made  broader, 


138  THE   DESCENT   OF  MAX.  [Paht  I. 

the  spine  peculiarly  curved  and  the  head  fixed  in  an  altered 
position,  and  all  these  changes  have  been  attained  by  man. 
Prof.  Schaafthausen"  maintains  that  "the  powci-ful mastoid 
processes  of  the  liuman  skull  are  the  result  of  his  erect 
posithsn ; "  and  these  i:)rocesses  are  absent  in  the  orang, 
chimpanzee,  etc.,  and  are  smaller  in  the  gorilla  than  in 
man.  Various  other  structures  might  here  have  been 
specified,  which  appear  connected  with  man's  erect  posi- 
tion. It  is  very  difficult  to  decide  how  far  all  those  cor- 
related modifications  are  the  result  of  natural  selection, 
and  how  far  of  the  inherited  effects  of  the  increased  use  of 
certain  parts,  or  of  the  action  of  one  part  on  another.  No 
doubt  these  means  of  change  act  and  react  on  each  other: 
thus  when  certain  muscles,  and  the  crests  of  bone  to  which 
they  are  attached,  beco'me  enlarged  by  habitual  use,  this 
shows  that  certain  actions  are  habitually  performed  and 
must  be  serviceable.  Hence  the  individuals  which  per- 
formed them  best,  would  tend  to  survive  in  greater  num- 
bers. 

The  free  use  of  the  arms  and  hands,  partly  the  cause 
and  partly  the  result  of  man's  erect  position,  appears  to 
have  led  in  an  indirect  manner  to  other  modifications  of 
structure.  The  early  male  progenitors  of  man  were,  as 
previously  stated,  probably  furnished  with  great  canine 
teeth ;  but  as  they  gradually  acquired  the  habit  of  using 
stones,  clubs,  or  other  weapons,  for  fighting  with  their 
enemies,  they  would  have  used  their  jaws  and  teeth  less 
and  less.  In  this  case,  the  jaws,  together  with  the  teeth, 
Ti^ould  have  become  reduced  in  size,  as  we  may  feel  sure 
from  innumerable  analogous  cases.  In  a  future  chapter  we 
shall  meet  with  a  closely-parallel  case,  in  the  reduction  or 
comjDlcte  disappearance  of  the  canine  teeth  in  male  rumi- 

•"  "Ou  tiio  I'rimilive  Form  of  the  Skull,"  translated  iii  '  Anthropo- 
logical Review,'  Oct.  18C8,  p.  428.  Owen  ('Anatomy  of  Vertebrates,' 
vol.  ii.  18G0,  p.  551)  on  the  mastoid  processes  in  the  higher  apes. 


Chap.  IV.]  MANNER   OF  DEVELOPMENT.  139 

nants,  apiDarently  in  relation  with  the  development  of 
their  horns ;  and  in  horses,  in  relation  with  their  habit  of 
fighting  with  their  incisor  teeth  and  hoofs. 

In  the  adult  male  anthropomorphous  apes,  as  Rliti- 
meyer,^^  and  others  have  insisted,  it  is  precisely  the  effect 
which  the  jaw-muscles  by  their  great  development  have 
produced  on  the  skull,  that  causes  it  to  differ  so  greatly  in 
many  respects  from  that  of  man,  and  has  given  to  it  "  a 
truly  frightful  physiognomy."  Therefore,  as  the  jaws  and 
teeth  m  the  progenitors  of  man  gradually  become  reduced 
in  size,  the  adult  skull  would  have  presented  nearly  the 
same  characters  which  it  offers  in  the  young  of  the  an- 
thropomorphous apes,  and  would  thus  have  come  to 
resemble  more  nearly  that  of  existing  man.  A  great  re- 
duction of  the  canine  teeth  in  the  males  would  almost  cer- 
tainly, as  we  shall  hereafter  see,  have  affected  through 
inheritance  the  teeth  of  the  females. 

As  the  various  mental  faculties  have  gradually  de- 
veloped, the  brain  would  almost  certainly  have  become 
larger.  No  one,  I  presume,  doubts  that  the  large  size  of 
the  brain  in  man,  relatively  to  his  body,  in  comparison  to 
that  of  the  gorilla  or  orang,  is  closely  connected  with  his 
higher  mental  powers.  We  meet  with  closely-analogous 
facts  with  insects,  in  which  the  cerebral  ganglia  are  of 
extraordinary  dimensions  ia  ants ;  these  ganglia  in  all  the 
Hymenoptera  being  many  times  larger  than  in  the  less  in- 
telligent orders,  such  as  beetles."  On  the  otlier  hand,  no 
one  supposes  that  the  intellect  of  any  two  animals,  or  of 
any  two  men,  can  be  accurately  gauged  by  the  cubic  con- 

*^  'Die  Grenzen  der  Thiei'welt,  cine  Ectraclitung  zu  Darwin's  Lehre,' 
1868,  s.  51. 

*'  Dujardin,  '  Annales  des  Sc.  Nat.'  3d  series,  Zoolog.  torn.  xiv.  1850, 
p.  203.  See  also  Mr.  Lowne,  '  Anatomy  and  Phys.  of  the  Ilusca  vomifo- 
Wa,'  18Y0,  p.  14.  My  son,  Mr.  F.  Darwin,  dissected  for  me  the  cerebral 
ganglia  of  the  Formica  rufa. 


140  TOE   DESCENT  OF  MAN.  [Part  I. 

tents  of  their  skulls.  It  is  certain  that  tliere  may  be  extraor- 
dinary mental  activity  with  an  extremely  small  absolute 
mass  of  nervous  matter ;  thus  the  wonderfully  diversified 
instincts,  mental  powers,  and  alTections  of  ants,  are  gen- 
erally known,  yet  their  cerebral  ganglia  are  not  so  large 
as  the  quarter  of  a  small  pin's  head.  Under  this  latter 
point  of  vievr,  the  brain  of  an  ant  is  one  of  the  most  mar- 
vellous atoms  of  matter  in  the  world,  perhaps  more  mar- 
vellous than  tlie  brain  of  man. 

The  belief  that  there  exists  in  man  some  close  relation 
between  the  size  of  the  brain  and  the  development  of  the 
intellectual  faculties  is  supported  by  the  comparison  of  the 
skulls  of  savage  and  civilized  races,  of  ancient  and  modem 
people,  and  by  the  analogy  of  the  whole  vertebrate  series. 
Dr.  J.  Barnard  Davis  has  proved '°  by  many  careful  meas- 
urements, that  the  mean  internal  capacity  of  the  skull  in 
Europeans  is  92.3  cubic  inches;  in  Americans  87.5;  in 
Asiatics  87.1 ;  and  in  Australians  only  81.9  inches.  Prof. 
Broca"  found  that  skulls  from  graves  in  Paris  of  the 
nineteenth  century,  were  larger  than  those  from  vaults  of 
the  twelfth  century,  in  the  proportion  of  1484  to  142G  ; 
and  Prichard  is  persuaded  that  the  present  inhabitants  of 
Britain  have  "  much  more  capacious  brain-cases  "  than  the 
ancient  inhabitants.  IsTevertheless  it  must  be  admitted 
that  some  skulls  of  very  high  antiquity,  such  as  the  famous 
one  of  Neanderthal,  are  well  developed  and  capacious. 
With  respect  to  the  lower  animals,  M.  E.  Lartet,"  by 
comparing  the  crania  of  tertiary  and  recent  mammals,  be- 
longing to  the  same-  groups,  has  come  to  the  remarkable 
conclusion  that  the  brain  is  generally  larger  and  the  con- 
volutions more  complex  in  the  more  recent  form.     On  the 

'0  'Philosophical  Transactions,'  1SG9,  p.  513. 

■='  Quoted  ia  C.  Vogt's  'Lectures  ou  Man,'  Eng.  translat.  1864,  pp.  88, 
90.     Prichard,  'Phys.  Hist,  of  Mankind,'  vol.  i.  1838,  p.  305. 
"  'Comptcs  Rend-js  dcs  Sdanecs,'  etc.,  June  1,  1868. 


Chap.  IV.]  MANNER   OF  DEVELOPMENT.  141 

other  liand,  I  hnve  shown"  that  the  braiiis  of  domestic 
rabbits  are  considerably  reduced  in  bulk,  in  comparison 
with  tliose  of  the  wild  rabbit,  or  hare ;  and  this  may  be 
attributed  to  their  having  been  closely  confined  during 
many  generations,  so  that  they  have  exerted  but  little 
their  intellect,  instincts,  senses,  and  voluntary  movements. 
The  gradually-increasing  weight  of  the  brain  and 
skull  in  man  must  have  influenced  the  development  of  the 
supporting  spinal  column,  more  especially  while  he  was 
becoming  erect.  As  this  change  of  position  was  being 
brought  about,  the  internal  pressure  of  the  brain  will, 
also,  have  influenced  the  form  of  the  skull ;  for  many  facts 
show  how  easily  the  skull  is  thus  aflected.  Ethnologists 
believe  that  it  is  modified  by  the  kind  of  cradle  in  which 
infants  sleep.  Habitual  spasms  of  the  muscles  and  a  cic- 
atrix from  a  severe  burn  have  permanently  modified  the 
facial  bones.  In  young  persons  whose  heads  from  disease 
have  become  fixed  either  sideways  or  backward,  one  of 
the  eyes  has  changed  its  position,  and  the  bones  of  the 
skull  have  been  modified;  and  this  apparently  results 
from  the  brain  pressing  in  a  new  direction.''*  I  have  shown 
that  with  long-eared  rabbits,  even  so  trifling  a  cause  as 
the  lo})ping  forward  of  one  ear  drags  forward  on  that  side 
almost  every  bone  of  the  skull ;  so  that  the  bones  on  the 
opposite  sides  no  longer  strictly  correspond.  Lastly,  if  any 
animal  were  to  increase  or  diminish  much  in  general  size, 
without  any  change  in  its  mental  powers ;  or  if  the  mental 

''^  '  The  Variation  of  Animals  and  Plants  under  Domestication,'  vol.  i. 
pp.  124-129. 

"  SchaafFhausen  gives  from  Blumenbach  and  Busch,  the  cases  of  the 
spasms  and  cicatrix,  in  '  Anthropolog.  Review,'  Oct.  1868,  p.  420.  Dr. 
Jarrold  (' Anthropologia,'  1808,  pp.  115,  116)  adduces  from  Camper  and 
from  his  own  observations,  cases  of  the  modification  of  the  skull  from 
the  head  being  fixed  in  an  unnatural  position.  He  believes  that  certain 
trades,  such  as  that  of  a  shoemaker,  by  causing  the  head  to  be  habitually 
held  forward,  makes  the  forehead  more  rounded  and  prominent. 


142  THE   DESCENT   OF   MAX.  [Part  I. 

powers  wore  to  be  much  increased,  or  diminished,  witliout 
any  great  chajige  in  the  size  of  the  body ;  the  shape  of 
tlic  skull  would  almost  certainly  be  altered.  I  infer  this 
from  my  observations  on  domestic  rabbits,  some  kinds  of 
which  have  become  verj^  much  larger  than  the  wild 
animal,  while  others  have  retained  nearly  the  same  size, 
but  in  both  cases  the  brain  has  been  much  reduced  rela- 
tively to  the  size  of  the  body.  Now  I  was  at  first  much 
surprised  by  finding  that  in  all  these  rabbits  the  skull  had 
become  elongated  or  dolichocephalic  ;  for  instance,  of  two 
skulls  of  nearly  equal  breadth,  the  one  from  a  wild  rabbit 
and  the  other  from  a  large  domestic  kind,  the  former  was 
only  3.15,  and  the  latter  4.3  inches  in  length.''  One  of 
the  most  marked  distinctions  in  different  races  of  man  is 
that  the  skull  in  some  is  elongated,  and  in  others  rounded ; 
and  here  the  explanation  suggested  by  the  case  of  the 
rabbits  may  jiartially  hold  good;  for  Welckcr  finds  that 
"short  men  incline  more  to  brachyccphaly,  and  tall  men 
to  dolichocephal}^ ; "  "  and  tall  men  may  be  compared  with 
the  larger  and  longer-bodied  rabbits,  all  of  which  have 
elongated  skulls,  or  are  dolichocephalic. 

From  these  several  facts  we  can  to  a  certain  extent 
understand  the  means  through  which  the  great  size  and 
more  or  less  rounded  form  of  the  skull  has  been  acquired 
by  man ;  and  these  are  characters  eminently  distinctive  of 
him  in  comparison  with  the  lower  animals. 

Another  most  conspicuous  difference  between  man  and 
the  lower  animals  is  the  nakedness  of  his  skin.  Whales 
and  dolphins  (Cetacca),  dugongs  (Sirenia),  and  the  hip- 
popotamus, are  naked ;  and  this  may  be  advantageous  to 
them  for  gliding  through  the  water;  nor  would  it  be  in- 

'*  'Variation  of  Animals,'  etc.,  vol.  i.  p.  117  on  the  elongation  of  the 
Bkull ;  p.  119,  on  the  efifcct  of  the  lopping  of  one  ear. 

"Quoted  by  Schaaffhauscn,  in  '  Anthropolog.  Revicv,-,'  Oct.  1808, 
p.  419. 


Chap.  IV.]  MANIs^ER   OF   DEVELOPMENT.  143 

jurioiis  to  tlicm  from  the  loss  of  warmth,  as  the  species 
which  inhabit  the  colder  regions  are  pi-otected  by  a  thick 
layer  of  blubber,  serving  the  same  purpose  as  the  fur  of 
seals  and  otters.  Elephants  and  rliinoceroses  are  almost 
hairless ;  and,  as  certain  extinct  species  which  formerly 
lived  under  an  arctic  climate  were  covered  with  long  wool 
or  hair,  it  would  almost  appear  as  if  the  existing  species 
of  both  genera  had  lost  their  hairy  covering  from  expos- 
ure to  heat.  This  appears  the  more  probable,  as  the 
elephants  in  India  which  live  on  elevated  and  cool  dis- 
tricts are  more  hairy  "  than  those  on  the  lowlands.  May 
we  then  infer  that  man  became  divested  of  hair  from  hav- 
ing aboriginally  inhabited  some  tropical  land  ?  The  fact 
of  the  hair  being  chiefly  retained  in  the  male  sex  on  the 
chest  and  face,  and  in  both  sexes  at  the  junction  of  all 
four  limbs  with  the  trunk,  favors  this  inference,  assuming 
that  the  hair  was  lost  before  man  became  erect ;  for  the 
parts  which  now  retain  most  hair  would  then  have  been 
most  protected  from  the  heat  of  the  sun.  The  crown  of 
the  head,  however,  offers  a  curious  exception,  for  at  all 
times  it  must  have  been  one  of  the  most  exposed  parts, 
yet  it  is  thickly  clothed  with  hair.  In  this  respect  man 
agrees  with  the  great  majority  of  quadrupeds,  which  gen- 
erally have  their  upper  and  exposed  surfaces  more  thickly 
clothed  than  the  lower  surface.  ISTevertheless,  the  fact 
that  the  other  members  of  the  order  of  Primates,  to  which 
man  belongs,  although  inhabiting  various  hot  regions,  are 
well  clothed  with  hair,  generally  thickest  on  the  upper 
surface,'^  is  strongly  opposed  to  the  supposition  that  man 
became  naked  through  the  action  of  the  sun,     I  am  in- 

''''  Owen,  'Anatomy  of  Vertebrates,'  vol.  iii.  p.  619. 

''^  Isidore  Geoffroy  St.-Hilaire  remarks  ('  Hist.  Nat.  Genorale,'  torn, 
ii.  1859,  pp.  215-21'?)  on  the  head  of  man  being  covered  with  long  hair ; 
also  on  the  upper  surfaces  of  monkeys  and  of  other  mammals  being  more 
thickly  clothed   than  the   lower  surfaces.     This  has  hkewise  been  ob- 


14i  THE   DESCENT   OF  MAX.  [Part  I. 

clined  to  believe,  as  we  shall  see  under  sexual  selection, 
that  man,  or  rathci*  primarily  woman,  became  divested  of 
hair  for  ornamental  purposes;  and  according  to  this  belief 
it  is  not  surprising  that  man  should  differ  so  greatly  in 
hairiness  from  all  his  lower  brethren,  for  characters  gained 
through  sexual  selection  often  differ  in  closely-related 
forms  to  an  extraordinary  degree. 

According  to  a  popular  impression,  the  absence  of  a 
tail  is  eminently  distinctive  of  man ;  but  as  those  apes 
which  come  nearest  to  man  are  destitute  of  this  organ, 
its  disappearance  does  not  especially  concern  us,  Nevei'- 
theless  it  may  be  well  to  own  that  no  explanation,  as  far 
as  I  am  aware,  has  ever  been  given  of  the  loss  of  the  tail 
by  certain  apes  and  man.  Its  loss,  however,  is  not  sur- 
prising, for  it  sometimes  differs  remarkably  in  length  in 
species  of  the  same  genera :  thus  in  some  species  of  Maca- 
cus  the  tail  is  longer  than  the  whole  body,  consisting  of 
twenty-four  vertebra? ;  in  others  it  consists  of  a  scarcely- 
visible  stump,  containing  only  three  or  four  vertebra?.  In 
some  kinds  of  baboons  there  are  twenty-five,  while  in  the 
mandrill  there  are  ten  very  small  stunted  caudal  vertebrre, 
or,  according  to  Cuvier,'"  sometimes  only  five.  This  great 
diversity  in  the  structure  and  length  of  the  tail  in  animals 
belonging  to  the  same  genera,  and  following  neai'ly  the 
same  habits  of  life,  renders  it  probable  that  the  tail  is  not 
of  mucli  importance  to  them  ;  and  if  so,  we  might  have  ex- 
pected that  it  Avould  sometimes  have  become  more  or  less 
rudimentary,  in  accordance  with  what  we  incessantly  see 

served  by  various  authors.  Prof.  P.  Gervais  ('Ilist.  Nat.  dcs  Mammi- 
f&res,'  torn.  i.  1854,  p.  28),  however,  states  that  in  the  Gorilla  the  hair  is 
thinner  on  the  back,  where  it  is  partly  rubbed  off,  than  on  the  lower  sur- 
face. 

"  Mr.  St.  George  Mivart,  '  Proc.  Zoolog.  Soc.'  18G5,  pp.  562,  583.  Dr. 
J.  E.  Gray,  '  Cat.  Brit.  Mus. :  Skeletons.'  Owen,  '  Anatomy  of  Verte- 
brates,' vol.  ii.  p.  51 Y.  Isidore  Geoffrey, '  Hist.  Nat.  G6n.'  torn.  ii.  p.  244. 


Chap.  IV.]  MANNER   OF  DEVELOPMENT.  145 

with  other  structures.  The  tail  almost  always  tapers 
toward  the  end,  whether  it  be  long  or  short ;  and  this,  I 
presume,  results  from  the  atrophy,  through  disuse,  of  the 
terminal  muscles,  together  with  their  arteries  and  nerves, 
leading  to  the  atrophy  of  the  terminal  bones.  With  re- 
spect to  the  OS  coccyx,  which  in  man  and  the  higher  apes 
manifestly  consists  of  the  few  basal  and  tapering  segments 
of  an  ordinary  tail,  I  have  heard  it  asked  how  could  these 
have  become  completely  embedded  within  the  body ;  but 
there  is  no  difficulty  in  this  respect,  for  in  many  monkeys 
the  basal  segments  of  the  true  tail  are  thus  embedded. 
For  instance,  Mr.  Murie  informs  me  that  in  the  skeleton  of 
a  not  full-grown  Macacus  inornatus,  he  counted  nine  or 
ten  caudal  vertebrse,  which  altogether  were  only  1,8  inch 
in  length.  Of  these  the  three  basal  ones  appeared  to  have 
been  embedded ;  the  remainder  forming  the  free  part  of 
the  tail,  which  was  only  one  inch  in  length,  and  half  an 
inch  in  diameter.  Here,  then,  the  three  embedded  caudal 
vertebrjB  plainly  correspond  with  the  four  coalesced  ver- 
tebrae of  the  human  os  coccyx. 

I  have  now  endeavored  to  show  that  some  of  the  most 
distinctive  characters  of  man  have  in  all  probability  been 
acquired,  either  directly,  or  more  commonly  indirectly, 
through  natural  selection.  We  should  bear  in  mind  that 
modifications  in  structure  or  constitution,  which  are  of  no 
service  to  an  oi'ganism  in  adapting  it  to  its  habits  of  life, 
to  the  food  which  it  consumes,  or  passively  to  the  sur- 
rounding conditions,  cannot  have  been  thus  acquired. 
We  must  not,  however,  be  too  confident  in  deciding  what 
modifications  are  of  service  to  each  being  :  we  should  re- 
member how  little  we  know  about  the  use  of  many  parts, 
or  what  changes  in  the  blood  or  tissues  may  serve  to  fit 
an  organism  for  a  new  climate  or  some  new  kind  of  food. 
Nor  must  we  forget  the  principle  of  correlation,  by  which, 


14G  THE  DESCENT   OF   MAX.  [Part  I. 

as  Isidore  GeolFroy  has  shown  in  the  case  of  man,  many 
stranfije  deviations  of  structure  are  tied  together.  Inde- 
pendently  of  correlation,  a  change  in  one  part  often  leads, 
through  the  increased  or  decreased  use  of  other  parts,  to 
other  changes  of  a  quite  unexpected  nature.  It  is  also 
well  to  reflect  on  such  facts,  as  the  wondei-ful  growth  of 
galls  on  plants  caused  by  the  poison  of  an  insect,  and  on 
the  remarkable  changes  of  color  in  the  plumage  of  parrots 
when  fed  on  certain  fishes,  or  inoculated  with  the  poison 
of  toads ;  *"  for  we  can  thus  see  that  the  fluids  of  the 
system,  if  altered  for  some  special  purpose,  might  induce 
other  strange  changes.  We  should  especially  bear  in 
mind  that  modifications  acquired  and  continually  used 
during  past  ages  for  some  useful  purpose  would  probably 
become  firmly  fixed  and  might  be  long  inherited. 

Thus  a  very  large  yet  undefined  extension  may  safely 
be  given  to  the  direct  and  indirect  results  of  natural  selec- 
tion ;  but  I  now  admit,  after  reading  the  essay  by  Xilgeli 
on  j^lants,  and  the  remarks  by  various  authors  with  respect 
to  animals,  more  especially  those  recently  made  by  Prof. 
Bi'oca,  that  in  the  earlier  editions  of  my  '  Origin  of  Spe- 
cies '  I  j)robably  attributed  too  much  to  the  action  of  natu- 
ral selection  or  the  survival  of  the  fittest.  I  have  altered 
the  fifth  edition  of  the  Origin  so  as  to  confine  my  remarks 
to  adaptive  changes  of  structure.  I  had  not  formerly 
sufficiently  considered  the  existence  of  many  structures 
which  appear  to  be,  as  far  as  we  can  judge,  neither  bene- 
ficial nor  injurious ;  and  this  I  believe  to  be  one  of  the 
greatest  oversights  as  yet  detected  in  my  work.  I  may 
be  permitted  to  say,  as  some  excuse,  that  I  had  two  dis- 
tinct objects  in  view,  firstly,  to  show  that  sj^ecies  had  not 
been  separately  created,  and  secondly,  that  natural  selec- 
tion had  been  the  chief  agent  of  change,  though  largely 

*"  '  The  Variation  of  Animals  and  Plants  under  Domestication,'  vol.  iu 
pp.  280,  282. 


Chaf.  IV.]  MANNER   OF   DEVELOPMENT.  147 

aided  by  the  inherited  eflects  of  habit,  and  slightly  by  the 
direct  action  of  the  surrounding  conditions.  Nevertheless 
I  was  not  able  to  annul  the  influence  of  my  former  belief, 
then  widely  prevalent,  that  each  spGcies  had  been  pur- 
posely created ;  and  this  led  to  my  tacitly  assuming  that 
every  detail  of  structure,  excepting  rudiments,  Avas  of 
some  special,  though  unrecognized,  service.  Any  one 
with  this  assumption  in  his  mind  would  naturally  extend 
the  action  of  natural  selection,  either  during  past  or  pres- 
ent times,  too  far.  Some  of  those  who  admit  the  principle 
of  evolution,  but  reject  natural  selection,  seem  to  forget, 
when  criticising  my  book,  that  I  had  the  above  two  ob- 
jects in  A'iew  ;  hence  if  I  have  erred  in  giving  to  natural 
selection  great  powei',  which  I  am  far  from  admitting,  or 
in  having  exaggerated  its  power,  which  is  in  itself  prob- 
able, I  have  at  least,  as  I  hope,  done  good  service  in  aid- 
ing to  overthrow  the  dogma  of  separate  creations. 

That  all  organic  beings,  including  man,  present  many 
modifications  of  structure  which  are  of  no  service  to  them 
at  present,  nor  have  been  formerly,  is,  as  I  can  now  see, 
probable.  We  know  not  what  produces  the  numberless 
slight  differences  between  the  individuals  of  each  species, 
for  reversion  only  carries  the  problem  a  few  steps  back- 
ward ;  but  each  peculiarity  must  have  had  its  own  efficient 
cause.  K  these  causes,  whatever  they  may  be,  were  to 
act  more  uniformly  and  energetically  during  a  lengthened 
period  (and  no  reason  can  be  assigned  why  this  should  not 
sometimes  occur),  the  result  would  probably  be  not  mere 
slight  individual  differences,  but  well-marked,  constant 
modifications.  Modifications  which  are  in  no  way  bene- 
ficial cannot  have  been  kept  uniform  through  natural  se- 
lection, though  any  which  were  injurious  would  have  been 
thus  eliminated.  Uniformity  of  character  would,  how- 
ever, naturally  follow  from  the  assumed  uniformity  of  the 
exciting  causes,  and  likewise  from  the  free  intercrossing 


148  TUE   DESCENT   OF   MAN".  [Part  I. 

of  many  individuals.  The  same  organism  might  acquire 
in  this  manner  during  successive  periods  successive  modi- 
fications, and  these  would  be  transmitted  in  a  nearly  uni- 
form state  as  long  as  the  exciting  causes  remained  the 
same  and  there  was  free  intercrossing.  With  respect  to 
the  exciting  causes  we  can  only  say,  as  when  speaking  of 
so-called  spontaneous  variations,  that  they  relate  much 
more  closely  to  the  constiiution  of  tlie  varying  organism, 
than  to  the  nature  of  the  conditions  to  which  it  has  been 
subjected. 

Conclusion. — In  this  chapter  we  have  seen  that  as  man 
at  the  present  day  is  liable,  like  every  other  animal,  to 
multiform  individual  differences  or  slight  variations,  so  no 
doubt  were  the  early  progenitors  of  man  ;  the  variations 
being  then  as  now  induced  by  the  same  general  causes, 
and  govei'ned  by  the  same  general  and  comj)lex  laws.  As 
all  animals  tend  to  multiply  beyond  their  means  of  sub- 
sistence, so  it  must  have  been  with  the  progenitors  of 
man  ;  and  this  will  inevitably  have  led  to  a  struggle  for 
existence  and  to  natural  selection.  This  latter  process 
will  have  been  greatly  aided  by  the  inherited  effects  of 
the  increased  use  of  parts  ;  these  two  processes  incessant- 
ly reacting  on  each  other.  It  appears,  also,  as  we  shall 
hereafter  see,  that  various  unimportant  characters  have 
been  acquired  by  man  through  sexual  selection.  An  unex- 
plained residuum  of  change,  perhaps  a  large  one,  must  be 
left  to  the  assumed  uniform  action  of  those  \inknown  agen- 
cies, which  occasionally  induce  strongly-marked  and  ab- 
rupt deviations  of  structure  in  our  domestic  productions. 

Judging  from  the  habits  of  savages  and  of  the  greater 
number  of  the  Quadrumana,  primeval  men,  and  even  the 
ape-like  progenitors  of  man,  probably  lived  in  society. 
With  strictly  social  animals,  natural  selection  sometimes 
acts  indirectly  on  the  individual,  through  the  preservation 


Chap.  IV.]  MANNER   OF   DEVELOPMENT.  149 

of  variations  which  are  beneficial  only  to  the  community. 
A  community  including  a  large  number  of  well-endowed 
individuals  increases  in  number  and  is  victorious  over 
other  and  less  well-endowed  communities  ;  although  each 
separate  member  may  gain  no  advantage  over  the  other 
members  of  the  same  community.  With  associated  in- 
sects many  remarkable  structures,  which  are  of  little  or 
no  service  to  the  individual  or  its  own  offspring,  such  as 
the  pollen-collecting  apparatus,  or  the  sting  of  the  worker- 
bee,  or  the  great  jaws  of  soldier-ants,  have  been  thus  ac- 
quired. With  the  higher  social  animals,  I  am  not  aware 
that  any  structure  has  been  modified  solely  for  the  good 
of  the  community,  though  some  are  of  secondary  service 
to  it.  For  instance,  the  horns  of  ruminants  and  the  great 
canine  teeth  of  baboons  appear  to  have  been  acquired  by 
the  males  as  weapons  for  sexual  strife,  but  they  are  used 
in  defence  of  the  herd  or  troop.  In  regard  to  certain 
mental  faculties  the  case,  as  we  shall  see  in  the  following 
chapter,  is  wholly  different ;  for  these  faculties  have  been 
chiefly,  or  even  exclusively,  gained  for  the  benefit  of  the 
community ;  the  individuals  composing  the  community 
being  at  the  same  time  indirectly  benefited. 

It  has  often  been  objected  to  such  views  as  the  fore- 
going, that  man  is  one  of  the  most  helpless  and  defence- 
less creatures  in  the  world ;  and  that  during  his  early  and 
less  well-developed  condition  he  would  have  been  still 
more  helpless.  The  Duke  of  Argyll,  for  instance,  insists  " 
that  "  the  human  frame  has  diverged  from  the  structure 
of  brutes,  in  the  direction  of  greater  physical  helplessness 
and  weakness.  That  is  to  say,  it  is  a  divergence  which  of 
all  others  it  is  most  impossible  to  ascribe  to  mere  natural 
selection."     He  adduces  the  naked  and  unprotected  state 

"  'Primeval  Man,'  1860,  p.  66. 


150  THE   DESCENT   OF  MAN.  [Part  I. 

of  the  body,  the  absence  of  great  teeth  or  cla-w's  for  de- 
fence, the  little  strength  of  man,  his  small  speed  in  run- 
ning, and  his  slight  power  of  smell,  by  which  to  discover 
food  or  to  avoid  danger.  To  these  deficiencies  there 
might  have  been  added  the  still  more  serious  loss  of  the 
power  of  quickly  climbing  trees,  so  as  to  escape  from  ene- 
mies. Seeing  that  the  unclothed  Fuegians  can  exist  under 
their  ■\\Tetchcd  climate,  the  loss  of  hair  would  not  have 
been  a  great  injury  to  primeval  man,  if  he  inhabited  a 
warm  count^3^  When  we  compare  defenceless  man  with 
the  apes,  many  of  which  are  provided  with  formidable 
canine  teeth,  we  must  remember  that  these  in  their  fully- 
developed  condition  are  possessed  by  the  males  alone, 
being  chiefly  used  by  them  for  fighting  with  their  rivals  ; 
yet  the  females,  which  are  not  thus  provided,  are  able  to 
survive. 

In  regard  to  bodily  size  or  strength,  we  do  not  know 
whether  man  is  descended  from  some  comparatively  small 
species,  like  the  chimpanzee,  or  from  one  as  powerful  as 
the  gorilla ;  and,  therefore,  we  cannot  say  whether  man 
has  become  larger  and  stronger,  or  smaller  and  weaker, 
in  comparison  with  his  progenitors.  We  should,  how- 
ever, bear  in  mind  that  an  animal  possessing  great  size, 
strength,  and  ferocity,  and  which,  like  the  gorilla,  could 
defend  itself  from  all  enemies,  would  probably,  though 
not  necessarily,  have  failed  to  become  social ;  and  thi^ 
would  most  eftectually  have  checked  the  acquirement  by 
man  of  his  higher  mental  qualities,  such  as  sympathy  and 
the  love  of  his  fellow-creatures.  Hence  it  might  have 
been  an  immense  advantage  to  man  to  have  sprung  from 
some  comparatively  weak  creature. 

The  slight  corporeal  strength  of  man,  his  little  speed, 
his  want  of  natural  weapons,  etc.,  are  more  than  counter- 
balanced, firstly  by  his  intellectual  powers,  through  which 
he  has,  while  still  remaining  in  a  barbarous  state,  formed 


CaiP.  IV.]  MANNER   OF  DEVELOPMENT.  151 

for  himself  weapons,  tools,  etc.,  and  secondly  by  his  social 
qualities  which  lead  him  to  give  aid  to  his  fellow-men  and 
to  receive  it  in  return.  No  country  in  the  world  abounds 
in  a  greater  degree  with  dangerous  beasts  than  Southern 
Africa;  no  country  presents  more  fearful  physical  hard- 
ships than  the  Arctic  regions ;  yet  one  of  the  puniest  races, 
namely,  the  Bushmen,  maintain  themselves  in  Southern 
Africa,  as  do  the  dwarfed  Esquimaux  in  the  Arctic 
regions.  The  early  progenitors  of  man  were,  no  doubt, 
inferior  in  intellect,  and  probably  in  social  disposition,  to 
the  lowest  existing  .savages ;  but  it  is  quite  conceivable 
that  they  might  have  existed,  or  even  flourished,  if,  while 
they  gradually  lost  their  brute-like  powers,  such  as  climb- 
ing trees,  etc.,  they  at  the  same  time  advanced  in  intellect. 
But  granting  that  the  progenitors  of  man  were  far  more 
helpless  and  defenceless  than  any  existing  savages,  if  they 
had  inhabited  some  warm  continent,  or  large  island,  such 
as  Australia  or  New  Guinea,  or  Borneo  (the  latter  island 
being  now  tenanted  by  the  orang),  they  would  not  have 
been  exposed  to  any  special  danger.  In  an  area  as  large 
as  one  of  these  islands,  the  competition  between  tribe  and 
tribe  would  have  been  sufficient,  under  favorable  con- 
ditions, to  have  raised  man,  through  the  survival  of  the 
fittest,  combined  with  the  inherited  effects  of  habit,  to  his 
present  high  position  in  the  organic  scale. 


162  THE  DESCENT   OF  MAN.  [Part  I. 


CHAPTER  V. 

ON  THE  DEVELOPMENT  OP  THE  INTELLECTUAL  AND  MOEAL 
FACULTIES    DURING   PKIMEVAL   AND    CIVILIZED    TIMES. 

The  Advancement  of  the  Intellectual  Powers  throuf^h  Natural  Selection. — 
Importance  of  Imitation. — Social  and  Moral  Faculties. — Their  Develop- 
ment within  the  Limits  of  the  same  Tribe. — Natural  Selection  as  af- 
fecting Civilized  Nations. — Evidence  that  Civilized  Nations  were  once 
barbarous. 

The  subjects  to  "be  discussed  in  tliis  chapter  are  of  the 
highest  interest,  but  are  treated  by  me  in  a  most  imperfect 
and  fragmentary  manner.  Mr.  Wallace,  in  an  admirable 
paper  before  referred  to,'  argues  that  man,  after  he  had 
partially  acquired  those  intellectual  and  moral  faculties 
Avhich  distinguish  him  from  the  lower  animals,  would  have 
been  biit  little  liable  to  have  had  his  bodily  structure 
modified  through  natural  selection  or  any  other  means. 
For  man  is  enabled  througli  his  mental  faculties  "  to  keep 
with  an  unchanged  body  in  harmony  with  the  changing 
universe."  He  has  great  power  of  adapting  his  habits  to 
new  conditions  of  life.  He  invents  weapons,  tools,  and 
various  stratagems,  by  which  he  pi'ocures  food  and  de- 
fends himself.  When  he  migrates  into  a  colder  climate 
he  uses  clothes,  builds  sheds,  and  makes  fires ;  and,  by  the 
aid  of  fire,  cooks  food  otherwise  indigestible.  He  aids  his 
fellow-men  in  many  ways,  and  anticipates  future  events. 

'  'Anthropological  Review,'  May,  1864,  p.  clviii. 


Chap.  Y.]  INTELLECTUAL  FACULTIES.  153 

Even  at  a  remote  period  lie  practised  some  subdivision  of 
labor. 

The  lower  animals,  on  the  other  hand,  must  have  their 
bodily  structure  modified  in  order  to  survive  under  great- 
Ij^-changed  conditions.  They  must  be  rendered  stronger, 
or  acquire  more  eiFective  teeth  or  claws,  in  order  to  defend 
themselves  from  new  enemies ;  or  they  must  be  reduced 
in  size  so  as  to  escape  detection  and  danger.  When  they 
migrate  into  a  colder  climate  they  must  become  clothed 
with  thicker  fur,  or  have  their  constitutions  altered.  If 
they  fail  to  be  thus  modified,  they  will  cease  to  exist. 

The  case,  however,  is  widely  different,  as  Mr.  Wallace 
has  with  justice  insisted,  in  relation  to  the  intellectual  and 
moral  faculties  of  man.  These  faculties  are  variable ;  and 
we  have  every  reason  to  believe  that  the  variations  tend 
to  be  inherited.  Therefore,  if  they  were  formerly  of  high 
importance  to  primeval  man  and  to  his  ape-like  pro- 
genitors, they  would  have  been  jDcrfected  or  advanced 
through  natural  selection.  Of  the  high  importance  of  the 
intellectual  faculties  there  can  be  no  dovibt,  for  man  main- 
ly owes  to  them  his  preeminent  position  in  the  world. 
We  can  see  that,  in  the  rudest  state  of  society,  the  indi- 
viduals who  were  the  most  sagacious,  who  invented  and 
used  the  best  weapons  or  traps,  and  who  were  best  able 
to  defend  themselves,  would  rear  the  greatest  number  of 
offspring.  The  tribes  which  included  the  largest  number 
of  men  thus  endowed  would  increase  in  number  and  sup- 
plant other  tribes.  Numbers  depend  primarily  on  the 
means  of  subsistence,  and  this,  partly  on  the  physical 
nature  of  the  country,  but  in  a  much  higher  degree  on  the 
arts  which  are  thei'e  practised.  As  a  tribe  increases  and 
is  victorious,  it  is  often  still  further  increased  by  the  ab- 
sorption of  other  tribes."  The  stature  and  strength  of  the 
men  of  a  tribe  are  likewise  of  some  importance  for  its  suc- 

*  After  a  time  the  members,  or  tribes,  which  are  absorbed  into  an- 


154  THE   DESCENT   OF   MAN.  [Paut  I 

cess,  and  these  depend  in  part  on  the  nature  and  amount 
of  the  food  Avliich  can  be  obtained.  In  Europe  the  men 
of  the  Bronze  period  were  supplanted  by  a  more  powerful 
and,  judging  from  their  sword-handlcs,  larger-handed 
race;^  but  their  success  was  probably  due  in  a  much 
higher  degree  to  their  superiority  in  the' arts. 

All  that  Ave  know  about  savages,  or  may  infer  from 
their  traditions  and  from  old  monuments,  the  history  of 
which  is  quite  forgotten  by  the  present  inhabitants,  shows 
that  from  the  remotest  times  successful  tribes  have  sup- 
planted other  tribes.  Relics  of  extinct  or  forgotten  tribes 
have  been  discovered  throiighout  the  civilized  regions  of 
the  earth,  on  the  Avild  plains  of  America,  and  on  the  iso- 
lated islands  in  the  Pacific  Ocean.  At  the  present  day 
civilized  nations  are  everywhere  supplanting  barbarous 
nations,  excepting  where  the  climate  opposes  a  deadly  bar- 
rier; and  they  succeed  mainly,  though  not  exclusively, 
through  their  arts,  which  are  the  j^roducts  of  the  intellect. 
It  is,  therefore,  highly  probable  that  with  mankind  the  in- 
tellectual faculties  have  been  gradually  perfected  through 
natural  selection ;  and  this  conclusion  is  sufficient  for  our 
pui'pose.  Undoubtedly  it  would  have  been  very  inter- 
esting to  have  traced  the  development  of  each  separate 
faculty  from  the  state  in  Avhich  it  exists  in  the  lower 
animals  to  that  in  which  it  exists  in  man ;  but  neither  my 
ability  nor  knoAvledge  permits  the  attempt. 

It  deserves  notice  that  as  soon  as  the  progenitors  of 
man  became  social  (and  this  probably  occurred  at  a  very 
early  period),  the  advancement  of  the  intellectual  faculties 
will  have  been  aided  and  modified  in  an  important  manner, 
of  which  we  see  only  traces  in  the  lower  animals,  namely, 
through  the  principle  of  imitation,  together  with  reason 

other  tribe  assume,  as  Mr.  Maine  remarks  ('Ancient  Law,'  1861,  p.  131), 
that  they  are  the  co-descendants  of  the  same  ancestors. 
3  Morlot,  '  Soc.  Vaud.  Sc.  Nat.'  1860,  p.  2Dt 


Chap,  v.]  INTELLECTUAL   FACULTIES.  I55 

and  experience.  Apes  ai-e  much  given  to  imitation,  as  are 
the  lowest  savages ;  and  the  simple  fact,  previously  re- 
ferred to,  that  after  a  time  no  animal  can  he  caught  in  the 
same  place  by  the  same  sort  of  trap,  shows  that  animals 
learn  by  experience,  and  imitate  each  other's  caution. 
Now,  if  some  one  man  in  a  tribe,  more  sagacious  than  the 
others,  invented  a  new  snare  or  weapon,  or  other  means 
of  attack  or  defence,  the  j)lainest  self-interest,  without  the 
assistance  of  much  reasoning  power,  would  prompt  the 
other  members  to  imitate  him ;  and  all  would  thus  j^rofit. 
The  habitual  practice  of  each  new  art  must  likewise  in 
some  slight  degree  strengthen  the  intellect.  If  the  new 
invention  were  an  important  one,  the  tribe  Avould  increase 
in  number,  spread,  and  supplant  other  tribes.  In  a  tribe 
thus  rendered  more  numerous  there  would  always  be  a 
rather  better  chance  of  the  birth  of  other  superior  and  in- 
ventive members.  If  such  men  left  children  to  inherit 
their  mental  superiority,  the  chance  of  the  birth  of  still 
more  ingenious  members  would  be  somewhat  better,  and 
in  a  very  small  tribe  decidedly  better.  Even  if  they  left 
no  children,  the  tribe  would  still  include  their  blood- 
relations  ;  and  it  has  been  ascertained  by  agriculturists  * 
that  by  preserving  and  breeding,  from  the  family  of  an 
animal,  which  when  slaughtered  was  found  to  be  valuable, 
the  desired  character  has  been  obtained. 

Turning  now  to  the  social  and  moral  faculties.  In 
order  that  primeval  men,  or  the  ape-like  progenitors  of 
man,  should  have  become  social,  they  must  have  acquired 
the  same  instinctive  feelings  which  impel  other  animals  to 
live  in  a  body ;  and  they  no  doubt  exhibited  the  same 
general  disposition.  They  would  have  felt  uneasy  when 
Beparated  from  their  comrades,  for  whom  they  would  have 

*  I  have  given  instances  in  my  '  Variation  of  Animals  under  Domesti- 
cation,' vol.  ii.  p.  196. 


156  THE   DESCENT   OF  MAN.  [Part  I. 

felt  some  degree  of  love ;  they  would  have  warned  each 
other  of  danger,  and  have  given  mutual  aid  in  attack  or 
defence.  All  this  implies  some  degree  of  sympathy,  fidel- 
ity, and  coui-age.  Such  social  qualities,  the  paramount 
importance  of  which  to  tlie  lower  animals  is  disputed  by 
no  one,  were  no  doubt  acquired  by  the  progenitors  of  man 
in  a  similal*  manner,  namely,  through  natural  selection, 
aided  by  inherited  habit.  When  two  tribes  of  primeval 
man,  living  in  the  same  country,  came  into  competition, 
if  the  one  tribe  included  (other  circumstances  being 
equal)  a  greater  number  of  courageous,  sympathetic,  and 
faithful  members,  who  were  always  ready  to  warn  each 
other  of  danger,  to  aid  and  defend  each  other,  this  tribe 
Avould  without  doubt  succeed  best  and  conquer  the  other. 
Let  it  be  borne  in  mind  how  all-important,  in  the  never- 
ceasing  wars  of  savages,  fidelity  and  courage  must  be. 
The  advantage  which  disciplined  soldiers  have  over  un- 
disciplined hordes  follows  chiefly  from  the  confidence 
which  each  man  feels  in  his  comrades.  Obedience,  as  Mr. 
Bagehot  has  well  shown,'  is  of  the  highest  value,  for  any 
form  of  government  is  better  than  none.  Selfish  and  con- 
tentious people  will  not  cohere,  and  without  coherence 
nothing  can  be  efiected.  A  tribe  possessing  the  above 
qualities  in  a  high  degree  woiild  spread  and  be  victorious 
over  other  tribes;  but  in  the  course  of  time  it  Avould, 
judging  from  all  past  history,  be  in  its  turn  ovei'come  by 
some  other  and  still  more  highly-endowed  tribe.  Thus 
the  social  and  moral  qualities  would  tend  slowly  to  ad- 
vance and  be  diffused  throughout  the  world. 

But  it  may  be  asked.  How  within  the  limits  of  the 
same  tribe  did  a  large  number  of  members  first  become 
endowed  with  these  social  and  moral  qualities,  and  how 
was  the  standai-d  of  excellence  raised  ?     It  is  extremely 

*  Sec  a  remarkable  series  of  articles  on  Physics  and  Politics  iu  the 
'Fortnightly  Review,'  Nov.  1867;  April  1,  1868  ;  July  1,  1869. 


Chap.  V.]  MORAL   FACULTIES.  157 

doubtful  whether  the  offspring  of  tlie  more  sympathetic 
and  benevolent  parents,  or  of  those  which  were  the  most 
faithful  to  their  comrades,  would  be  reared  in  greater 
number  than  the  children  of  selfish  and  treacherous  par- 
ents of  the  same  tribe.  He  who  was  ready  to  sacrifice  his 
life,  as  many  a  savage  has  been,  rather  than  betray  his 
comrades,  would  often  leave  no  oflspring  to  inherit  nis 
noble  nature.  The  bravest  men,  who  were  always  willing 
to  come  to  the  front  in  war,  and  who  freely  risked  their 
lives  for  others,  would  on  an  average  perish  in  larger  num- 
ber than  other  men.  Therefore  it  seems  scarcely  possible 
(bearing  in  mind  that  we  are  not  here  speaking  of  one 
tribe  being  victorious  over  another)  that  the  number  of 
men  gifted  with  such  virtues,  or  that  the  standard  of  their 
excellence,  could  be  increased  through  natural  selection, 
that  is,  by  the  survival  of  the  fittest. 

Although  the  circumstances  which  lead  to  an  increase 
in  the  number  of  men  thus  endowed  within  the  same  tribe 
are  too  complex  to  be  clearly  followed  out,  we  can  trace 
some  of  the  probable  steps.  In  the  first  place,  as  the  rea- 
soning powers  and  foresight  of  the  members  became  im- 
proved, each  man  would  soon  learn  from  experience  that, 
if  he  aided  his  fellow-men,  he  would  commonly  receive  aid 
in  return.  From  this  low  motive  he  might  acquire  the 
habit  of  aiding  his  fellows ;  and  the  habit  of  performing 
benevolent  actions  certainly  strengthens  the  feeling  of 
sympathy,  which  gives  the  first  impulse  to  benevolent  ac- 
tions. Habits,  moreover,  followed  during  many  genera- 
tions probably  tend  to  be  inherited. 

But  there  is  another  and  much  more  powerful  stimulus 
to  the  development  of  the  social  vii^tues,  namely,  the 
praise  and  the  blame  of  our  fellow-men.  The  love  of  ap- 
probation and  the  dread  of  infamy,  as  well  as  the  be- 
stowal of  praise  or  blame,  are  primarily  due,  as  we  have 
seen  in  the  third  chapter,  to  the  instinct  of  sympathy ; 


158  THE   DESCENT   OF   MAN.  [Part  I. 

and  this  instinct  no  doubt  was  originally  acquired,  like  all 
tlic  other  social  instincts,  through  natural  selection.  At 
how  early  a  period  the  progenitors  of  man,  in  the  course 
of  their  development,  became  capable  of  feeling  and  being 
impelled  by  the  praise  or  blame  of  their  fellow-creatures, 
w^  cannot,  of  course,  say.  But  it  appears  that  even  dogs 
appreciate  encouragement,  praise,  and  blame.  The  rudest 
savages  feel  the  sentiment  of  gloiy,  as  they  clearly  show 
by  preserving  the  trophies  of  their  prowess,  by  their 
liabit  of  excessive  boasting,  and  even  by  the  extreme  care 
which  they  take  of  their  personal  appearance  and  decora- 
tions ;  for  unless  tliey  regarded  the  opinion  of  their  com- 
rades, such  habits  would  be  senseless. 

They  certainly  feel  shame  at  the  breach  of  some  of 
their  lesser  rules ;  but  how  far  they  experience  remorse  is 
doubtful.  I  was  at  first  surprised  that  I  could  not  recol- 
lect any  recorded  instances  of  this  feeling  in  savages  ;  and 
Sir  J.  Lubbock '  states  that  he  knows  of  none.  But  if  Ave 
banish  from  our  minds  all  cases  given  in  novels  and  plays 
and  in  death-bed  confessions  made  to  priests,  I  doubt 
whether  many  of  us  hav.e  actually  vritnessed  remorse; 
though  we  may  have  often  seen  shame  and  contrition  for 
smaller  offences.  Remorse  is  a  deeply-hidden  feeling.  It 
is  incredible  that  a  savage,  who  will  sacrifice  his  life 
rather  than  betray  his  tribe,  or  one  who  will  deliver  him- 
self up  as  a  prisoner  rather  than  break  his  parole,'  would 
not  feel  remorse  in  his  inmost  soul,  though  he  might  con- 
ceal  it,  if  he  had  failed  in  a  duty  which  he  held  sacred. 

We  may  therefore  conclude  that  primeval  man,  at  a 
very  remote  pei-iod,  would  have  been  influenced  by  the 
praise  and  blame  of  his  fellows.  It  is  obvious,  that  the 
members  of  the  same  tribe   would   approve   of  conduct 

6  'Origin  of  Civilization,'  1870,  p.  2G5. 

'  Mr.  Wallace  gives  cases  in  his  '  Contributions  to  the  Theory  of 
Natural  Selection,'  1870,  p  331. 


Chap.  Y.]  MORAL   FACULTIES.  159 

which  appeared  to  them  to  be  for  the  general  good,  and 
would  reprobate  that  which  appeai*ed  evil.  To  do  good 
unto  others — to  do  unto  others  as  ye  Yv'ould  they  should 
do  unto  you — is  the  foundation-stone  of  morality.  It  is, 
therefore,  hardly  possible  to  exaggerate  the  importance 
during  rude  times  of  the  love  of  praise  and  the  dread  of 
blame,  A  man  who  was  not  impelled  by  any  deep,  in- 
stinctive feeling,  to  sacrifice  his  life  for  the  good  of  others, 
yet  was  roused  to  such  actions  by  a  sense  of  glory,  would 
by  his  example  excite  the  same  wish  for  glory  in  other 
men,  and  would  strengthen  by  exercise  the  noble  feeling 
of  admiration.  He  might  thus  do  far  more  good  to  his 
tribe  than  by  begetting  ofispring  with  a  tendency  to  in- 
herit his  own  high  character. 

With  increased  experience  and  reason,  man  perceives 
the  more  remote  consequences  of  his  actions,  and  the  self- 
regarding  virtues,  such  as  temperance,  chastity,  etc., 
which  during  early  times  arc,  as  we  have  before  seen, 
utterly  disregarded,  come  to  be  highly  esteemed  or  even 
held  sacred.  I  need  not,  however,  repeat  what  I  have 
said  on  this  head  in  the  third  chaj)ter.  Ultimately  a 
highly-complex  sentiment,  having  its  first  origin  in  the 
social  instincts,  largely  guided  by  the  approbation  of  our 
fellow-men,  ruled  by  reason,  self-interest,  and  in  later 
times  by  deep  religious  feelings,  confirmed  by  instruction 
and  habit,  all  combined,  constitute  our  moral  sense  or  con- 
science. 

It  must  not  be  forgotten  that,  although  a  high  stand- 
ard of  morality  gives  but  a  slight  or  no  advantage  to  each 
individual  man  and  his  children  over  the  other  men  of  the 
same  tribe,  yet  that  an  advancement  in  the  standard  of 
morality  and  an  increase  in  the  number  of  well-endowed 
men  will  certainly  give  an  immense  advantage  to  one 
tribe  over  another.  There  can  be  no  doubt  that  a  tribe 
includin.g  many  members  who,  from  possessing  in  a  liigh 


160  THE   DESCENT   OF   MAN.  [Part  I. 

degree  the  spirit  of  patriotism,  fidelity,  obedience,  courage, 
and  sympathy,  -were  always  ready  to  give  aid  to  each 
other  and  to  sacrifice  themselves  for  the  common  good, 
"would  be  victorious  over  most  other  tribes ;  and  this 
•would  be  natural  selection.  At  all  times  throughout  the 
world  tribes  have  supplanted  other  tribes ;  and  as  morali- 
ty is  one  element  in  their  success,  the  standard  of  morality 
and  the  number  of  well-endowed  men  will  thus  every- 
where tend  to  rise  and  increase. 

It  is,  however,  very  difficult  to  form  any  judgment 
why  one  particular  tribe  and  not  another  has  been  success- 
ful and  has  risen  in  the  scale  of  civilization.  Many  sav- 
ages are  in  the  same  condition  as  when  first  discovered 
several  centuries  ago.  As  Mr.  Bagehot  has  remarked,  we 
are  apt  to  look  at  progress  as  the  normal  rule  in  human 
society ;  but  history  refutes  this.  The  ancients  did  not 
even  entertain  the  idea  ;  nor  do  the  Oriental  nations  at  the 
present  day.  According  to  another  high  authority,  Mr. 
Maine,*  "  the  greatest  part  of  mankind  has  never  shown  a 
particle  of  desire  that  its  civil  institutions  should  be  im- 
proved." Progress  seems  to  depend  on  many  concurrent 
favorable  conditions,  far  too  complex  to  be  followed  out. 
But  it  has  often  been  remarked,  that  a  cool  climate  from 
leading  to  industry  and  the  various  arts  has  been  highly 
favorable,  or  even  indispensable  for  this  end.  The  Esqui- 
maux, pressed  by  hard  necessity,  have  succeeded  in  many 
ingenious  inventions,  but  their  climate  has  been  too  severe 
for  continued  progress.  Nomadic  habits,  whether  over 
wide  plains,  or  through  the  dense  forests  of  the  tropics,  or 
along  the  shores  of  the  sea,  have  in  every  case  been  highly 
detrimental.  While  observing  the  barbai'ous  inhabitants 
of  Tierra  del  Fuego,  it  struck  me  that  the  possession  of 
some  property,  a  fixed  abode,  aud  the  union  of  many  fami- 

8 'Ancient  Law,'  18G1,  p.   22.     For  Mr.  Bagehot'3  remarks,  ' Fort- 
nightly Review,'  April  1,  1868,  p.  432. 


Chap.  V.]  CIVILIZED   NATIONS.  161 

lies  under  a  chief,  were  tlie  indispensable  requisites  for 
civilization.  Such  habits  almost  necessitate  the  cultiva- 
tion of  the  ground ;  and  the  first  steps  in  cultivation 
would  probably  result,  as  I  have  elsewhere  shown,'  from 
some  such  accident  as  the  seeds  of  a  fruit-tree  falling  on  a 
heap  of  refuse  and  producing  an  unusually  fine  variety. 
The  problem,  however,  of  the  first  advance  of  savages 
toward  civilization  is  at  present  much  too  difficult  to  be 
solved. 

Natural  Selection  as  affecting  Civilized  Nations. — In 
the  last  and  present  chapters  I  have  considered  the  ad- 
vancement of  man  from  a  former  semi-human  condition 
to  his  present  state  as  a  barbarian.  But  some  remarks 
on  the  agency  of  natural  selection  on  civilized  nations 
may  be  here  worth  adding.  This  subject  has  been  ably 
discussed  by  Mr.  W.  R.  Greg,'"  and  previously  by  Mr. 
Wallace  and  Mr.  Galton."  Most  of  ray  remarks  are 
taken  from  these  three  authors.  With  savages,  the  weak 
in  body  or  mind  are  soon  eliminated ;  and  those  that  sur- 
vive commonly  exhibit  a  vigorous  state  of  health.  "We 
civilized  men,  on  the  other  hand,  do  our  utmost  to  check 
the  process  of  elimination ;  we  build  asylums  for  the  un- 

^  '  The  A''aiiation  of  Animals  and  Plants  under  Domestication,'  vol.  i. 
p,  309. 

'"Traser's  Magazine,'  Sept.  1868,  p.  353.  This  article  seems  to 
have  struck  many  persons,  and  has  given  rise  to  two  remarkable  essays 
and  a  rejoinder  in  the  '  Spectator,'  Oct.  3  and  17,  18G8.  It  has  also 
been  discussed  in  the  '  Q.  Journal  of  Science,'  1869,  p.  152,  and  by  Mr. 
Lawson  Tait  in  the  'Dublin  Q.  Journal  of  Medical  Science,'  Feb.  1869, 
and  by  Mr.  E.  Eay  Lankester  in  his  '  Comparative  Longevity,'  1870,  p. 
128.  Similar  views  appeared  previously  in  the  'Australasian,'  July  13, 
1867.     I  have  borrowed  ideas  from  several  of  these  writers. 

"  For  Mr.  Wallace,  see  '  Anthropolog.  Review,'  as  before  cited.  Mr. 
Galton  in  'Macmillan's  Magazine,'  Aug.  1865,  p.  318;  also  his  great 
work,  '  Hereditary  Genius,'  1 870. 


162  THE  DESCENT  OF  MAX.  [Part  L 

becilc,  tlie  muiined,  and  the  sick  ;  we  institute  jioor-laws  ; 
and  our  medical  men  exert  tlieir  utmost  skill  to  save  the 
life  of  every  one  to  the  last  moment.  There  is  reason  to 
believe  that  vaccination  has  preserved  thousands,  who 
from  a  -weak  constitution  would  formerly  have  succumbed 
io  small-i:)0x.  Thus  the  Aveak  members  of  civilized  socie- 
ties propagate  their  kind.  Ko  one  who  has  attended  to 
the  breeding  of  domestic  animals  will  doubt  that  this 
must  be  highly  injurious  to  the  race  of  man.  It  is  sur- 
prising how  soon  a  want  of  care,  or  care  wrongly  directed, 
leads  to  the  degeneration  of  a  domestic  race ;  but  except- 
ing in  the  case  of  man  himself,  hardly  any  one  is  so  igno- 
rant as  to  allow  his  worst  animals  to  breed. 

The  aid  Avhich  we  feel  impelled  to  give  to  the  helpless 
is  mainly  an  incidental  result  of  the  instinct  of  sympathy, 
which  was  originally  acquired  as  part  of  the  social  in- 
stincts, but  suljsequently  rendered,  in  the  manner  pre- 
viously indicated,  more  tender  and  more  widely  diffused. 
Nor  could  we  check  our  sympathy,  if  so  urged  by  hard 
reason,  without  deterioration  in  the  noblest  part  of  our 
nature.  The  surgeon  may  harden  himself  while  perform- 
ing an  operation,  for  he  knows  that  he  is  acting  for  the 
good  of  Ills  patient ;  but  if  we  were  intentionally  to  neg- 
lect the  Avcak  and  helpless,  it  could  only  be  for  a  con- 
tingent benefit,  with  a  certain  and  great  present  evil. 
Hence  we  must  bear  without  com2:)laining  the  undoubtedly 
bad  effects  of  the  weak  surviving  and  propagating  their 
kind ;  but  there  appears  to  be  at  least  one  check  in  steady 
action,  namely  tlie  weaker  and  inferior  members  of  society 
not  marrying  so  freely  as  the  sound ;  and  this  check  might 
be  indefinitely  increased,  though  this  is  more  to  be  hoped 
for  than  expected,  by  the  weak  in  body  or  mind  refraining 
from  marriage. 

Ill  all  civilized  countries  man  accumulates  property 
and  bequeaths  it  to  his  children.     So  that  the  children  in 


Chap,  v.]  CIVILIZED   NATIONS.  1C3 

the  same  country  do  not  by  any  means  start  fair  in  the 
race  for  success.  But  this  is  far  from  an  unmixed  evil ; 
for  without  the  accumulation  of  capital  the  arts  could  not 
progress ;  and  it  is  chiefly  through  their  power  that  the 
civilized  races  have  extended,  and  are  now  everywhere 
extending,  their  range,  so  as  to  take  the  place  of  the  lower 
races.  Nor  does  the  moderate  accumulation  of  wealth 
interfere  with  the  process  of  selection.  When  a  poor  man 
becomes  rich,  his  children  enter  trades  or  professions  in 
which  there  is  struggle  enough,  so  that  the  able  in  body 
and  mind  succeed  best.  The  presence  of  a  body  of  well- 
instructed  men,  who  have  not  to  labor  for  their  daily 
bread,  is  important  to  a  degree  which  cannot  be  over- 
estimated ;  as  all  high  intellectual  work  is  carried  on  by 
them,  and  on  such  work  material  progress  of  all  kinds 
mainly  depends,  not  to  mention  other  and  higher  advan- 
tages. No  doubt  wealth,  when  very  great,  tends  to  con- 
vert men  into  useless  drones,  but  their  number  is  never 
large ;  and  some  degree  of  elimination  here  occurs,  as  we 
daily  see  rich  men,  who  happen  to  be  fools  or  profligate, 
squandering  away  all  their  wealth. 

Primogeniture  with  entailed  estates  is  a  more  direct 
evil,  though  it  may  formerly  have  been  a  great  advantage 
by  the  creation  of  a  dominant  class,  and  any  government 
is  better  than  anarchy.  The  eldest  sons,  though  they 
may  be  weak  in  body  or  mind,  generally  marry,  while  the 
younger  sons,  however  superior  in  these  respects,  do  not 
so  generally  marry.  Nor  can  worthless  eldest  sons  with 
entailed  estates  squander  their  wealth.  But  here,  as  else- 
where, the  relations  of  civilized  life  are  so  complex  that 
some  compensatory  checks  intervene.  The  men  who  are 
rich  through  primogeniture  are  able  to  select  generation 
after  generation  the  more  beautiful  and  charmmg  women ; 
and  these  must  generally  be  healthy  in  body  and  active 
in  mind.     The  evil  consequences,  such  as  they  may  be,  of 


164  THE  DESCENT   OF  MAN.  [Part  I. 

the  contiiiuecl  preservation  of  the  same  line  of  descent, 
without  any  selection,  are  checked  by  men  of  rank  always 
wishing  to  increase  their  wealth  and  power ;  and  this  they 
ciFect  by  marrying  heiresses.  But  the  daughters  of  parents 
who  have  produced  single  children,  are  themselves,  aS 
Mr.  Galton  has  shown,"  apt  to  be  sterile ;  and  thus  noble 
families  are  continually  cut  off  in  the  direct  line,  and  their 
wealth  flows  into  some  side-channel ;  but  unfortunately 
this  channel  is  not  determined  by  superiority  of  any  kind. 

Although  civilization  thus  checks  in  many  ways  the 
action  of  natural  selection,  it  apparently  favors,  by  means 
of  improved  food  and  the  freedom  from  occasional  hard- 
ships, the  better  development  of  the  body.  This  may  be 
inferred  from  civilized  men  having  been  found,  wherever 
compared,  to  be  physically  stronger  than  savages.  They 
appear  also  to  have  equal  powers  of  endurance,  as  has 
been  proved  in  many  adventurous  expeditions.  Even  the 
gi'cat  luxury  of  the  rich  can  be  but  little  detrimental ;  for 
the  expectation  of  life  of  our  aristocracy,  at  all  ages  and 
of  both  sexes,  is  very  little  inferior  to  that  of  healthy  Eng- 
lish lives  in  the  lower  classes." 

We  will  now  look  to  the  intellectual  faculties  alone. 
If  in  each  grade  of  society  the  members  Avere  divided 
into  two  equal  bodies,  the  one  including  the  intellectually 
superior  and  the  other  the  inferior,  there  can  be  little 
doubt  tliat  the  former  would  succeed  best  in  all  occupa- 
tions and  rear  a  greater  number  of  children.  Even  in  the 
lowest  walks  of  life,  skill  and  ability  must  be  of  some  ad- 
vantage, though  in  many  occupations,  owing  to  the  great 
division  of  labor,  a  very  small  one.  Hence  in  civilized 
nations  there  will  be  some  tendency  to  an  increase  both 

'2  'Ilereditary  Genius,'  1810,  pp.  132-140. 

'^  See  the  fifth  and  sLsth  columns,  compiled  from  good  authorities,  in 
the  table  given  in  Mr.  E.  R.  Lankcster's  'Comparative  Longevity,'  1870, 
p.  116. 


Chap.  V.]  CIVILIZED   NATIONS.  165 

in  the  number  and  in  the  standard  of  the  intellectually 
able.  But  I  do  not  wish  to  assert  that  this  tendency  may 
not  be  more  than  counterbalanced  in  other  ways,  as  by 
the  multiplication  of  the  reckless  and  improvident ;  but 
even  to  such  as  these,  ability  must  be  some  advantage. 

It  has  often  been  objected  to  views  like  the  foregoing, 
that  the  most  eminent  men  who  have  ever  lived  have  left 
no  offspring  to  inherit  their  great  intellect.  Mr.  Galton 
says,"  "  I  regret  I  am  unable  to  solve  the  simple  question 
whether,  and  how  far,  men  and  women  who  are  prodigies 
of  genius  are  infex-tile.  I  have,  however,  shown  that  men 
of  eminence  are  by  no  means  so."  Great  lawgivers,  the 
founders  of  beneficent  religions,  great  philosophers  and 
discoverers  in  science,  aid  the  progress  of  mankind  in  a 
far  higher  degree  by  their  works  than  by  leaving  a  nu- 
merous progeny.  In  the  case  of  corporeal  structures,  it 
is  the  selection  of  the  slightly  better-endowed  and  the 
elimination  of  the  slightly  less  well-endowed  individuals, 
and  not  the  preservation  of  strongly-marked  and  rare 
anomalies,  that  leads  to  the  advancement  of  a  species." 
So  it  will  be  with  the  intellectual  faculties,  namely,  from 
the  somewhat  more  able  men  in  each  grade  of  society 
succeeding  rather  better  than  the  less  able,  and  conse- 
quently increasing  in  number,  if  not  otherwise  prevented. 
When  in  any  nation  the  standard  of  intellect  and  the 
number  of  intellectual  men  have  increased,  we  may  ex- 
pect from  the  law  of  the  deviation  from  an  average,  as 
shoAvn  by  Mr.  Galton,  that  prodigies  of  genius  will  appear 
somewhat  more  frequently  than  before. 

In  regard  to  the  moral  qualities,  some  elimination  of 
the  worst  dispositions  is  always  in  progress  even  in  the 
most  civilized  nations.  Malefactors  are  executed,  or  im- 
prisoned for  long  periods,  so  that  they  cannot  freely  trans* 

'*  'Hereditary  Genius,'  18Y0,  p.  330. 

'°  Origin  of  Species'  (fifth  edition,  1869),  p.  104. 


1G6  THE   DESCENT   OF   MAN.  [Pabt  I. 

mit  ihcif  bad  qualities.  Melancholic  and  insane  persons 
are  confined,  or  commit  suicide.  Violent  and  quarrel- 
some men  often  come  to  a  bloody  end.  Restless  men  who 
will  not  follow  any  steady  occupation — and  this  relic  of 
barbarism  is  a  great  check  to  civilization '" — emigi'ate  to 
newly-settled  countries,  Avhere  they  prove  useful  pioneers. 
Intemperance  is  so  highly  destructive,  that  the  expecta- 
tion of  life  of  the  intemperate,  at  the  age,  for  instance, 
of  thirty,  is  only  13,8  years;  while  for  the  rural  laborers 
of  England  at  the  same  age  it  is  40,59  years."  Pi'ofligate 
women  bear  few  children,  and  profligate  men  rarely 
marry ;  both  sufier  from  disease.  In  the  breeding  of  do- 
mestic animals,  the  elimination  of  those  individuals,  though 
few  in  number,  which  are  in  any  marked  manner  inferior, 
is  by  no  means  an  unimportant  element  toward  success. 
This  esjiecially  holds  good  with  injurious  characters  which 
tend  to  reappear  through  reversion,  such  as  blackness  in 
sheep ;  and  with  mankind  some  of  the  worst  dispositions 
which  occasionally  without  any  assignable  cause  make 
their  appearance  in  families,  may  perhaps  be  reversions 
to  a  savage  state,  from  which  we  are  not  removed  by  very 
many  generations.  This  view  seems  indeed  I'ccognized  in 
the  common  expression  that  such  men  are  the  black  sheep 
of  the  family. 

With  civilized  nations,  as  far  as  an  advanced  stand- 
ard of  morality,  and  an  increased  number  of  fairly  well- 
endowed  men  are  concerned,  natural  selection  apparently 
effects  but  little ;  though  the  fundamental  social  instincts 
were  originally  thus  gained.  But  I  have  already  said 
enough,  while  treating  of  the  lower  races,  on  the  causes 

'5  'Ildreditary  Genius,'  1870,  p.  847. 

'' E.  Ray  Laiikcster,  'Comparative  Longevity,'  1870,  p.  115.  The 
table  of  the  intemperate  is  from  Neison's  '  Vital  Statistics.'  In  regard  to 
profligacy,  see  Dr.  Farr,  "Influence  of  Marriage  on  Moi'tality,"  'Xat. 
Assoc,  for  the  Promotion  of  Social  Science,'  1858. 


Chap.  V.]  CIVILIZED   NATIONS.  16  7 

which  lead  to  the  advance  of  morality,  namely,  the  ap- 
probation of  our  fellow-men — ^the  strengthening  of  our 
sympathies  by  habit — example  and  imitation — reason — 
experience  and  even  self-interest — instruction  during  youth, 
and  religious  feelings. 

A  most  important  obstacle  in  civilized  countries  to  an 
increase  in  the  number  of  men  of  a  superior  class  has 
been  strongly  urged  by  Mr.  Greg  and  Mr.  Galton,"  namely, 
the  fact  that  the  very  poor  and  reckless,  who  are  often 
degraded  by  vice,  almost  invariably  marry  early,  while 
the  careful  and  frugal,  who  are  generally  otherwise  virtu- 
ous, marry  late  in  life,  so  that  they  may  be  able  to  sup- 
port themselves  and  their  children  in  comfort.  Those 
who  marry  early  produce  within  a  given  period  not  only 
a  greater  number  of  generations,  but,  as  shown  by  Dr. 
Duncan,"  they  produce  many  more  children.  The  chil- 
dren, moreover,  that  are  born  by  mothers  during  the 
25rime  of  life  are  heavier  and  largei*,  and  therefore  prob- 
ably more  vigorous,  than  those  born  at  other  periods. 
TIius  the  reckless,  degraded,  and  often  vicious  members 
of  society,  tend  to  increase  at  a  quicker  rate  than  the 
provident  and  generally  virtuous  members.  Or  as  Mr. 
Greg  puts  the  case :  "  The  careless,  squalid,  unaspiring 
Irishman  multiplies  like  rabbits :  the  frugal,  foreseeing, 
self-respecting,  ambitious  Scot,  stern  in  his  morality,  spir- 
itual in  his  faith,  sagacious  and  disciplined  in  his  intelli- 
gence, passes  his  best  years  in  struggle  and  in  celibacy, 
marries  late,  and  leaves  few  behind  him.  Given  a  land 
originally  peopled  by  a  thousand  Saxons  and  a  thousand 

IS  '  Fraser's  Magazine,' Sept.  1868,  p.  353.  'Macmillan's  Magazine,' 
Aug.  1865,  p.  318.  Tlie  Rev.  F.  W.  Farrar  ('Fraser's  Mag.,'  Aug.  1870, 
p.  264)  takes  a  different  view. 

'^  "  On  the  Laws  of  the  Fertility  of  Women,"  in  '  Transact.  Royal 
Soc.'  Edinburgh,  vol.  xx!v.  p.  287.  See,  also,  Mr.  Galton,  '  Hereditary 
Genius,'  pp.  352-357,  for  observations  to  the  above  effect. 


168  THE   DESCENT   OF  MAX.  [Part  I. 

Celts — and  in  a  dozen  generations  five-sixths  of  the  popu- 
lation would  be  Celts,  but  fivc^sixths  of  the  property,  of 
the  po-wcr,  of  the  intellect,  would  belong  to  the  one-sixth 
of  Saxons  that  remained.  In  the  eternal  '  struggle  for 
existence,'  it  would  be  the  inferior  and  less  favored  race 
that  had  prevailed — and  prevailed  by  virtue  not  of  its 
good  qualities  but  of  its  faults." 

There  are,  however,  some  checks  to  this  downward 
tendency.  'SVe  have  seen  that  the  intemperate  suffer  from 
a  high  rate  of  mortality,  and  the  extremely  profligate 
leave  few  offspring.  The  poorest  classes  crowd  into  towns, 
and  it  has  been  proved  by  Dr.  Stark  from  the  statistics  of 
ten  years  in  Scotland,"  that  at  all  ages  the  death-rate  is 
higher  in  towns  than  in  rural  districts,  "and  during  the 
first  five  years  of  life  the  town  death-rate  is  almost  ex- 
actly double  that  of  the  rural  districts."  As  these  returns 
include  both  the  rich  and  the  poor,  no  doubt  more  than 
double  the  number  of  births  would  be  requisite  to  keep 
up  the  number  of  the  very  poor  inhabitants  in  the  towns, 
relatively  to  those  in  the  country.  With  women,  mar- 
riage at  too  early  an  age  is  highly  injurious;  for  it  has 
been  found  in  France  that  "  twice  as  many  wives  under 
twenty  die  in  the  year,  as  died  out  of  the  same  number 
of  the  iinmarried."  The  mortality,  also,  of  husbands  un- 
der twenty  is  "  excessively  high,"  ^^  but  what  the  cause  of 
this  may  be  seems  doubtful.  Lastly,  if  the  men  who  pru- 
dently delay  marrying  until  they  can  bring  up  their 
families  in  comfort,  were  to  select,  as  they  often  do,  wo- 
men in  the  prime  of  life,  the  rate  of  increase  in  the  better 
class  woxtld  be  only  slightly  lessened. 

It  was  established  from  an  enormous  body  of  statistics, 

«o  'Tenth  Annual  Report  of  Births,  Deaths,  etc.,  in  Scotland,'  1867, 
p.  xxix. 

^^  These  quotations  arc  taken  from  our  highest  authority  on  such 
questions,  namely,  Dr.  Farr,  in  his  paper  "  On  the  Influence  of  Marriage 


Chap.  Y.]  CIVILIZED  NATIONS.  169 

taken  during  1853,  that  the  nnmarriecl  men  throughout 
France,  between  the  ages  of  twenty  and  eighty,  die  in  a 
much  larger  proportion  than  the  married:  for  instance, 
out  of  every  1,000  unmarried  men,  between  the  ages  of 
twenty  and  thirty,  11.3  annually  died,  while  of  the  married 
only  6.5  died."  A  similar  law  was  proved  to  hold  good, 
during  the  years  1863  and  1864,  with  the  entire  popula- 
tion above  the  age  of  twenty  in  Scotland :  for  instance, 
out  of  every  1,000  unmarried  men,  between  the  ages  of 
twenty  and  thirty,  14.97  annually  died,  while  of  the  mar- 
ried only  V.24  died,  that  is,  less  than  half."  Dr.  Stark  re- 
marks on  this  :  "  Bachelorhood  is  more  destructive  to  life 
than  the  most  unwholesome  trades,  or  than  residence  in 
an  unwholesome  house  or  district  where  there  has  never 
been  the  most  distant  attempt  at  sanitary  improvement." 
He  considers  that  the  lessened  mortality  is  the  direct  re- 
sult of  "  marriage,  and  the  more  regular  domestic  habits 
which  attend  that  state."  He  admits,  however,  that  the 
intemperate,  profligate,  and  criminal  classes,  whose  dura- 
tion of  life  is  low,  do  not  commonly  marry ;  and  it  must 
likewise  be  admitted  that  men  with  a  weak  constitution, 
ill  health,  or  any  great  infirmity  in  body  or  mind,  will 
ofteii  not  wish  to  marry,  or  Avill  be  rejected.  Dr.  Stark 
seems  to  have  come  to  the  conclusion  that  marriage  in 
itself  is  a  main  cause  of  prolonged  life,  from  finding  that 
aged  married  men  still  have,  a  considerable  advantage  in 
this  respect  over  the  unmarried  of  the  same  advanced  age ; 

on  the  Mortality  of  the  French  People,"  read  before  the  Nat.  Assoc,  for 
the  Promotion  of  Social  Science,  1858. 

'^  Dr.  Farr,  ibid.  The  quotations  given  below  are  extracted  from  the 
same  striking  paper. 

'^  I  have  taken  the  mean  of  the  quinquennial  means,  given  in  '  The 
Tenth  Annual  Report  of  Births,  Deaths,  etc.,  in  Scotland,'  1867.  The 
quotation  from  Dr.  Siark  is  copied  from  an  article  in  the  '  Daily  News,' 
Oct.  17,  1868,  which  Dr.  Farr  considers  very  carefully  written. 


170  TnE   DESCENT   OF   MAN.  [Paiit  1. 

but  every  one  must  have  known  instances  of  men,  avIio 
with  weak  liealth  during  youth  did  not  marry,  and  yet  have 
Riirvived  to  old  age,  though  remaining  weak  and  there- 
fore always  with  a  lessened  chance  of  life.  There  is  anoth- 
er remarkable  circumstance  which  seems  to  support  Dr. 
Stark's  conclusion,  namely,  that  widows  and  widowers  in 
France  suffer  in  comparison  with  tlie  married  a  very  heavy 
rate  of  mortality ;  but  Dr.  Fan*  attributes  this  to  the  j^ov- 
erty  and  evil  habits  consequent  on  the  disruption  of  the 
family,  and  to  grief.  On  the  whole  we  may  conclude  with 
Dr.  Farr  that  the  lesser  mortality  of  married  than  of  im- 
married  men,  which  seems  to  be  a  general  law,  "  is  mainly 
due  to  the  constant  elimination  of  imperfect  types,  and  to 
the  skilful  selection  of  the  finest  individuals  out  of  each 
successive  generation ;  "  the  selection  relating  only  to  the 
marriage  state,  and  acting  on  all  coi-poreal,  intellectual, 
and  moral  qualities.  "We  may,  therefore,  infer  that  sound 
and  good  men  who  out  of  prudence  remain  for  a  time  un- 
married do  not  suffer  a  high  rate  of  mortality. 

If  the  various  checks  sjieeified  in  the  two  last  paragraphs, 
and  perhaps  others  as  yet  unknown,  do  not  prevent  the  reck- 
less, the  vicious,  and  othei'wise  inferior  members  of  society 
from  increasing  at  a  quicker  rate  than  the  better  class  of 
men,  the  nation  will  retrograde,  as  has  occurred  too  often 
in  the  history  of  the  world.  "We  must  remember  that  prog- 
ress is  no  invariable  rule.  It  is  most  difficult  to  say  why  one 
civilized  nation  rises,  becomes  more  powerful,  and  spreads 
more  widely,  than  another ;  or  why  the  same  nation  pro- 
gresses more  at  one  time  than  at  another.  We  can  only  say 
that  it  depends  on  an  increase  in  the  actual  number  of  the 
])opulation,  on  the  number  of  the  men  endowed  with  high  in- 
tellectual and  moral  faculties,  as  well  as  on  their  standard 
of  excellence.  Corporeal  structure,  except  so  far  as  vigor  of 
body  leads  to  vigor  of  mind,  appears  to  have  little  influence. 

It  has  been  urged  by  several  writers  that  as  high  in- 


Chap.  V.]  CIVILIZED  NATIONS.  171 

tellectual  powers  are  advantageous  to  a  nation,  the  old 
Greeks,  who  stood  some  grades  higher  in  intellect  than  any 
race  that  has  ever  existed,^*  ought  to  have  risen,  if  the 
power  of  natiu'al  selection  were  real,  still  higher  in  the 
scale,  increased  in  number,  and  stocked  the  whole  of  Eu- 
rope. Here  we  have  the  tacit  assumption,  so  often  made 
with  respect  to  corj)oreal  structures,  that  there  is  some  in- 
nate tendency  toward  continued  development  in  mind  and 
body.  But  development  of  all  kinds  depends  on  many 
concurrent  favorable  circumstances,  Natural  selection 
acts  only  in  a  tentative  manner.  Individuals  and  races 
may  have  acquired  certain  indisputable  advantages,  and 
yet  have  i^erished  from  failing  in  other  characters.  The 
Greeks  may  have  retrograded  from  a  want  of  coherence 
between  the  many  small  states,  from  the  small  size  of  their 
whole  country,  from  the  practice  of  slavery,  or  from  ex- 
treme sensuality ;  for  they  did  not  succumb  until  "  they 
were  enervated  and  corrupt  to  the  very  core.'"'^  The 
western  nations  of  Europe,  who  now  so  immeasurably  sur- 
pass their  former  savage  progenitors  and  stand  at  the  sum- 
mit of  civilization,  owe  little  or  none  of  their  superiority  to 
direct  inheritance  from  the  old  Greeks ;  though  they  owe 
much  to  the  MTitten  works  of  this  wonderful  people. 

Who  can  positively  say  why  the  Spanish  nation,  so 
dominant  at  one  time,  has  been  distanced  in  the  race?  The 
awakening  of  the  nations  of  Europe  from  the  dark  ages  is 
a  still  more  perplexing  problem.  At  this  early  period,  as 
Mr.  Galton ""  has  remarked,  almost  all  the  men  of  a  gentle 

-•*  See  the  ingenious  and  original  argument  on  this  subject  by  Mr. 
Galton,  '  Hereditary  Genius,'  pp.  340-3^2. 

^'^  Mr.  Greg,  '  Fraser's  Magazine,'  Sept.  1868,  p.  357. 

26  '  Hereditary  Genius,'  ISW,  pp.  357-359.  The  Rev.  F.  H.  Farrar 
('  Fraser's  Mag.',  Aug.  1870,  p.  257)  advances  arguments  on  the  other 
side.  Sir  C.  Lyell  had  already  (' Principles  of  Geology,' vol.  ii.  1868, 
p.  430)  called  attention,  in  a  striking  passage,  to  the  evil  influence  of  the 


172  THE   DESCENT   OF   MAX.  [Pap.t  I, 

nature,  those  given  to  meditation  ox-  culture  of  the  mind, 
had  no  refuge  except  in  the  bosom  of  the  Church  which 
demanded  celibacy ;  and  this  could  hardly  fail  to  have  had 
a  deteriorating  influence  on  each  successive  generation. 
During  this  same  period  the  Holy  Inquisition  selected  with 
extreme  care  the  freest  and  boldest  men  in  order  to  burn 
or  imprison  them.  In  Spain  ulone  some  of  the  best  men — 
those  who  doubted  and  questioned,  and  without  doubting 
there  can  be  no  progress — were  eliminated  during  three 
centuries  at  the  rate  of  a  thousand  a  year.  The  evil  which 
the  Catholic  Church  has  thus  effected,  though  no  doubt 
counterbalanced  to  a  certain,  perhaps  large  extent  in  other 
ways,  is  incalculable ;  nevertheless,  Europe  has  progressed 
at  an  unparalleled  rate. 

The  remarkable  success  of  the  English  as  colonists 
over  other  European  nations,  which  is  well  illustrated  by 
comparing  the  progress  of  the  Canadians  of  English  and 
French  extraction,  has  been  ascribed  to  their  "  daring  and 
persistent  energy;"  but  who  can  say  how  the  English 
gained  their  energy  ?  There  is  apparently  mucli  truth  in 
the  belief  that  the  wonderful  progi-ess  of  the  United  States, 
as  well  as  the  character  of  the  people,  are  the  results  of 
natural  selection ;  the  more  energetic,  restless,  and  coura- 
geous men  from  all  parts  of  Europe  havmg  emigrated 
during  the  last  ten  or  twelve  generations  to  that  great 
country,  and  having  there  succeeded  best."^  Looking  to 
the  distant  future,  I  do  not  think  that  the  Rev.  Mr.  Zincke 
takes  an  exaggerated  view  when  he  says:"  "All  other 
series  of  events — as  that  which  resulted  in  the  culture  of 
mind  in  Greece,  and  that  which  resulted  in  the  empire  of 

Holy  Inquisition  in  having  lowered,  through  selection,  the  general  stand- 
ard of  intelligence  in  Europe. 

"  Mr.  Gallon,  '  Macmillan's  Magazine,'  August,  18G5,  p.  325.  See, 
also,  'Nature,'  "  On  Darwinism  and  National  Life,"  Dec.  1869,  p.  184. 

*8  '  Last  Winter  in  the  United  States,'  1868,  p.  29. 


Chap.  V.]  CIVILIZED  NATIONS.  173 

Rome — only  appear  to  have  purpose  and  value  when 
viewed  in  connection  with,  or  rather  as  subsidiary  to  .  .  . 
the  great  stream  of  Anglo-Saxon  emigration  to  the  west." 
Obscure  as  is  the  problem  of  the  advance  of  civilization, 
we  can  at  least  see  that  a  nation  which  produced  during  a 
lengthened  period  the  greatest  number  of  highly  intellec- 
tual, energetic,  brave,  patriotic,  and  benevolent  men,  would 
generally  prevail  over  less  favored  nations. 

Natural  selection  follows  from  the  struggle  for  exist- 
ence ;  and  this  from  a  rapid  rate  of  increase.  It  is  impos- 
sible not  bitterly  to  regret,  but  whether  wisely  is  another 
question,  the  rate  at  which  man  tends  to  increase ;  for  this 
leads  in  barbarous  tribes  to  infanticide  and  many  other 
evils,  and  in  civilized  nations  to  abject  poverty,  celibacy, 
and  to  the  late  marriages  of  the  prudent.  But  as  man 
suffers  from  the  same  physical  evils  with  the  lower  animals, 
he  has  no  right  to  expect  an  immunity  from  the  evils  con- 
sequent on  the  struggle  for  existence.  Had  he  not  been 
subjected  to  natural  selection,  assuredly  he  would  never 
have  attained  to  the  rank  of  manhood.  When  we  see  in 
many  parts  of  the  world  enormous  areas  of  the  most  fer- 
tile land  peopled  by  a  few  wandering  savages,  but  which 
are  capable  of  supporting  numerous  happy  homes,  it 
might  be  argued  that  the  struggle  for  existence  had  not 
been  sufficiently  severe  to  force  man  upward  to  his  highest 
standard.  Judging  from  all  that  we  know  of  man  and  the 
lower  animals,  there  has  always  been  sufficient  variability 
in  the  intellectual  and  moral  faculties,  for  their  steady  ad- 
vancement through  natural  selection.  No  doubt  such 
advancement  demands  many  favorable  concurrent  circum- 
stances; but  it  may  well  be  dou.bted  whether  the  most 
favorable  would  have  sufficed,  had  not  the  rate  of  increase 
been  rapid,  and  the  consequent  struggle  for  existence 
severe  to  an  extreme  degree. 


1V4  THE  DESCENT   OF  MAX.  [pAni  I. 

On  the  evidence  that  all  civilized  nations  xcere  once 
barbarous. — As  we  have  had  to  consider  the  steps  by 
•whicli  some  semi-human  creature  lias  been  gradually  raised 
to  the  rank  of  man  in  his  most  perfect  f^tate,  the  present 
subject  cannot  be  quite  passed  over.  But  it  has  been 
treated  in  so  full  and  admirable  a  manner  by  Sir  J.  Lul- 
bock,"°  Mr.  Tylor,  Mr.  M'Lennan,  and  others,  that  I  need 
here  give  only  the  briefest  summary  of  their  results.  The 
arguments  recently  advanced  by  the  Duke  of  Argyll'" 
and  formerly  by  Archbishop  Whately,  in  favor  of  the  be- 
lief that  man  came  into  the  world  as  a  civilized  being  and 
that  all  savages  have  since  undergone  degradation,  seem 
to  me  weak  in  comparison  with  those  advanced  on  the 
other  side.  Many  nations,  no  doubt,  have  fallen  away  in 
civilization,  and  some  may  have  lapsed  into  utter  bar- 
barism, though  on  this  latter  head  I  have  not  met  with 
any  evidence.  The  Fuegians  were  probably  compelled  by 
other  conquering  hordes  to  settle  in  their  inhospitable 
country,  and  they  may  have  become  in  consequence  some- 
what more  degraded ;  but  it  would  be  difficult  to  prove 
that  they  have  fallen  much  below  the  Botocudos  who  in- 
habit the  finest  parts  of  Brazil. 

The  evidence  that  all  civilized  nations  are  the  de- 
scendants of  barbarians,  consists,  on  the  one  side,  of  clear 
traces  of  their  former  low  condition  in  still-existing  cus- 
toms, beliefs,  language,  etc. ;  and,  on  the  other  side,  of 
proofs  that  savages  are  independently  able  to  raise  them- 
selves a  few  steps  in  the  scale  of  civilization,  and  have 
actually  thus  risen.  The  evidence  on  the  first  head  is 
extremely  curious,  but  cannot  be  here  given  :  I  refer  to 
such  cases  as  that,  for  instance,  of  the  art  of  enumeration, 
which,  as  Mr.  Tylor  clearly  shows  by  the  words  still  used 

"  '  On  the   Origin   of  Civilizatiou,'    '  Proc.    Ethnological   Soc'  Nov. 
26,  1867. 

«"  Primeval  Man,'  1800. 


Chap.  V.]  CIVILIZED   iS'ATIOXS.  1 75 

in  some  places,  originated  in  counting  the  fingers,  first  of 
one  hand  and  then  of  the  other,  and  lastly  of  the  toes. 
We  have  traces  of  this  in  our  own  decimal  system,  and  in 
the  Roman  numerals,  which  after  reaching  to  the  number 
v.,  change  into  VI.,  etc.,  when  the  other  hand  no  doubt 
was  used.  So  again,  "  when  we  speak  of  tlireescore  and 
ten,  we  are  counting  by  the  vigesimal  system,  each  score 
thus  ideally  made,  standing  for  20 — for  'one  man'  as 
a  Mexican  or  Carib  would  put  it."  "  According  to  a  large 
and  increasing  school  of  philologists,  every  language  bears 
the  marks  of  its  slow  and  gradual  evolution.  So  it  is  with 
the  art  of  writing,  as  letters  are  rudiments  of  pictorial 
representations.  It  is  hardly  possible  to  read  Mr.  M'Len- 
nan's  work  "  and  not  admit  that  almost  all  civilized  nations 
still  retain  some  traces  of  siich  rude  habits  as  the  forcible 
capture  of  wives.  What  ancient  nation,  as  the  same  author 
asks,  can  be  named  that  was  originally  monogamous? 
The  primitive  idea  of  justice,  as  shown  by  the  law  of 
battle  and  other  customs  of  which  traces  still  remain,  was 
likewise  most  rude.  Many  existing  superstitions  are  the 
remnants  of  former  false  religious  beliefs.  The  highest 
form  of  religion — the  grand  idea  of  God  hating  sin  and 
loving  righteousness  —  was  unknown  during  primeval 
times. 

Turnincf  to  the  other  kind  of  evidence :  Sir  J.  Lubbock 
has  shown  that  some  savages  have  recently  imj)roved  a 
little  in  some  of  their  simpler  arts.     From  the  extremely 

31  ' Koyal  Institution  of  Great  Britain,'  March  15,  1867.  Also,  'Re- 
searches info  the  Early  History  of  Mankind,'  1865. 

3'^  '  Primitive  Marriage,'  1865.  See,  likewise,  an  excellent  article, 
evidently  by  the  same  author,  in  the  'North  British  Review,'  July,  1869. 
Also,  Mr.  L.  H.  Morgan,  "A  Conjectural  Solution  of  the  Origin  of  the 
Class.  System  of  Relationship,"  in  '  Proc.  American  Acad,  of  Sciences,' 
vol.  vii.  Feb.  1868.  Prof.  Schaaffhausen  ('  Anthropolog.  Review,'  Oct. 
1869,  p.  373)  remarks  on  "tlie  vestiges  of  human  sacrifices  found  both 
in  Homer  and  the  Old  Testament." 


178  THE   DESCENT   OF  MAN.  [Part  I. 

curious  account  which  he  gives  of  the  -weapons,  tools,  and 
arts,  used  oi*  practised  by  savages  in  various  parts  of  the 
world,  it  cannot  be  doubted  that  these  have  nearly  all 
been  independent  discoveries,  excepting  perhaps  the  art 
of  making  fire."  The  Australian  boomerang  is  a  good  in- 
stance  of  one  such  independent  discovery.  The  Tahitians 
when  first  visited  had  advanced  in  many  respects  beyond 
the  inhabitants  of  most  of  the  other  Polynesian  islands. 
There  are  no  just  grounds  for  the  belief  that  the  high  cidture 
of  the  native  Peruvians  and  Mexicans  was  derived  from 
any  foreign  source ;  '*  many  native  plants  were  there  cul- 
tivated, and  a  few  native  animals  domesticated.  We 
should  bear  in  mind  that  a  wandering  crew  from  some 
semi-civilized  land,  if  washed  to  the  shores  of  America, 
would  not,  judging  from  the  small  influence  of  most  mis- 
sionaries, have  produced  any  marked  effect  on  the  natives, 
unless  they  had  already  become  somewhat  advanced. 
Looking  to  a  very  remote  period  in  the  history  of  the 
world,  we  find,  to  use  Sir  J.  Lubbock's  well-known  terms, 
a  paleolithic  and  neolithic  period ;  and  no  one  will  pretend 
that  the  art  of  grinding  rough  flint  tools  was  a  borrowed 
one.  In  all  parts  of  Europe,  as  far  east  as  Greece,  in  Pal- 
estine, India,  Japan,  New  Zealand,  and  Africa,  including 
Egypt,  flint  tools  have  been  discovered  in  abundance ;  and 
of  their  use  the  existing  inhabitants  retain  no  tradition. 
There  is  also  indirect  evidence  of  their  former  use  by  the 
Chinese  and  ancient  Jews.  Hence  there  can  hardly  be  a 
doubt  that  the  inhabitants  of  these  many  countries,  which 
include  nearly  the  whole  civilized  world,  were  once  in  a 
barbarous  condition.  To  believe  that  man  was  aboriginally 
civilized  and  then  suffered  utter  degradation  in  so  many 

33  Sir  J.  Lubbock,  'Prehistoric  Times,'  2d  edit.  1860,  chaps,  xr.  and 
xvi.  et  passim. 

3^  Dr.  F.  Muller  has  made  some  good  remarks  to  this  effect  in  tho 
Rcise  dcr  Novara :  Anthropolog.  Thcil,'  Abtheil.  iii.  1868,  s.  127. 


Chap,  v.]  CIVILIZED  NATIONS.  177 

regions,  is  to  take  a  pitiably  low  view  of  human  nature. 
It  is  apparently  a  truer  and  more  cheerful  view  that  prog- 
ress has  been  much  more  general  than  retrogression ;  that 
man  has  risen,  though  by  slow  and  interrupted  steps,  from 
a  lowly  condition  to  the  highest  standard  as  yet  attained 
by  him  in  knowledge,  morals,  and  religion. 


1V8  THE   DESCENT   OF  MAN.  [Part  I. 


CHAPTER    VI. 

ox   THE    AFFINITIES    AND    GENEALOGY    OF    MAN. 

Position  of  Man  in  tlie  Animal  Series. — The  Natural  System  genealogical. 
— Adaptive  Characters  of  Slight  Value. — Various  Small  Points  of  Re- 
semblance between  Man  and  the  Quadrumana. — Eank  of  Man  in  the 
Natural  System. — Birthplace  and  Antiquity  of  Man. — Absence  of 
Fossil  Connecting-links. — Lower  Stages  in  the  Genealogy  of  Man,  as 
inferred,  firstly  from  his  Affinities  and  secondly  from  his  Structure. — 
Early  Androgynous  Condition  of  the  Vertebrata. — Conclusion. 

Even  if  it  be  granted  that  the  difference  between  man 
and  his  nearest  allies  is  as  great  in  cor^^oreal  structure  as 
some  naturalists  maintain,  and  although  we  must  grant 
that  the  difference  between  them  is  immense  in  mental 
power,  yet  the  facts  given  in  the  previous  chapters  de- 
clare, as  it  appears  to  me,  in  the  plainest  manner,  that 
man  is  descended  from  some  lower  form,  notwithstanding 
that  connecting-links  have  not  hitherto  been  discovered. 

Man  is  liable  to  numerous,  slight,  and  diversified  varia- 
tions, which  are  induced  by  the  same  general  causes,  are 
governed  and  transmitted  in  accordance  with  the  same 
general  laws,  as  in  the  lower  animals.  Man  tends  to  mul- 
tiply at  so  rapid  a  rate  that  his  offspring  are  necessarily 
exposed  to  a  struggle  for  existence,  and  consequently  to 
natural  selection.  He  has  given  rise  to  many  races,  some 
of  which  arc  so  different  that  they  have  often  been  ranked 
by  naturalists  as  distinct  species.  His  body  is  constructed 
on  the  same  homological  plan  as  that  of  other  mammals, 


Chap.  VI.]  AFFINITIES  AND   GENEALOGY.  179 

independently  of  the  uses  to  which  the  several  parts  may- 
be put.  He  passes  through  the  same  phases  of  embryo- 
logical  development.  He  retains  many  rudimentary  and 
useless  structures,  which  no  doubt  were  once  serviceable. 
Characters  occasionally  make  their  reappearance  in  him, 
which  we  have  every  reason  to  believe  were  possessed  by 
his  early  progenitors.  If  the  origin  of  man  had  been 
wholly  different  from  that  of  all  other  animals,  these  va- 
rious appearances  would  be  mere  empty  deceptions ;  but 
such  an  admission  is  incredible.  These  appeai*ances,  on 
the  other  hand,  are  intelligible,  at  least  to  a  large  extent, 
if  man  is  the  co-descendant  with  other  mammals  of  some 
unknown  and  lower  form. 

Some  naturalists,  from  being  deeply  impressed  with 
the  mental  and  spiritual  powers  of  man,  have  divided  the 
whole  organic  world  into  three  kingdoms,  the  Human,  the 
Animal,  and  the  Vegetable,  thus  giving  to  man  a  separate 
kingdom.*  Spiritual  powers  cannot  be  compared  or  classed 
by  the  naturalist ;  but  he  may  endeavor  to  show,  as  I  have 
done,  that  the  mental  faculties  of  man  and  the  lower  ani- 
mals do  not  differ  in  kind,  although  immensely  in  degree. 
A  difference  in  degree,  however  great,  does  not  justify  us 
in  placing-  man  in  a  distinct  kingdom,  as  will  perhaps  be 
best  illustrated  by  comparing  the  mental  powers  of  two 
insects,  namely,  a  coccus  or  scale-insect  and  an  ant,  which 
vmdoubtedly  belong  to  the  same  class.  The  difference  is 
here  greater,  though  of  a  somewhat  different  kind,  than 
that  between  man  and  the  highest  mammal.  The  female 
coccus,  while  young,  attaches  itself  by  its  proboscis  to  a 
plant ;  sucks  the  sap,  but  never  moves  again ;  is  fertilized 
and  lays  eggs ;  and  this  is  its  whole  history.  On  the 
other  hand,  to  describe  the  habits  and  mental  powers  of  a 

'  Isidore  Geoffrey  St.-Hilaire  gives  a  detailed  account  of  the  position 
assigned  to  man  by  various  naturalists  in  their  classifications  :  '  Hist. 
Nat.  Gen.'  torn.  ii.  1859,  pp.  lYO-189. 


180  THE   DESCENT   OF   MAX.  [Part  I. 

female  aut,  would  require,  as  Pierre  Iluber  has  shown,  a 
large  volume;  I  may,  however,  briefly  specify  a  few  points. 
Ants  communicate  information  to  each  other,  and  several 
imite  for  the  same  work,  or  games  of  play.  They  recog- 
nize their  fellow-ants  after  montlis  of  absence.  They  build 
great  edifices,  keep  them  clean,  close  the  doors  in  the  even- 
ing, and  post  sentries.  They  make  roads,  and  even  tun- 
nels under  rivers.  They  collect  food  for  the  community, 
and  when  an  object,  too  large  for  entrance,  is  brought  to 
the  nest,  they  enlarge  the  door,  and  afterward  build  it  up 
again.''  They  go  out  to  battle  in  regular  bands,  and  free- 
ly sacrifice  their  lives  for  the  common  weal.  They  emi- 
grate in  accordance  with  a  preconcerted  plan.  They  cap- 
ture slaves.  They  keep  Aphides  as  milch-cows.  They 
move  the  eggs  of  their  aphides,  as  well  as  their  own  eggs 
and  cocoons,  into  warm  parts  of  the  nest,  in  order  that 
they  may  be  quickly  hatched;  and  endless  similar  facts 
could  be  given.  On  the  whole,  the  difference  in  mental 
power  between  an  ant  and  a  coccus  is  immense;  yet  no 
one  has  ever  dreamed  of  placing  them  in  distinct  classes, 
much  less  in  distinct  kingdoms.  No  doubt  this  interval  is 
bridged  over  by  the  intermediate  mental  powers  of  many 
others  insects ;  and  this  is  not  the  case  with  man  and  the 
higher  apes.  But  we  have  every  reason  to  believe  that 
breaks  in  the  scries  are  simply  the  result  of  many  forms 
having  become  extinct. 

Prof.  Owen,  relying  chiefly  on  the  structure  of  tlu 
brain,  has  divided  the  mammalian  series  into  four  sub 
classes.  One  of  these  he  devotes  to  man ;  in  another  lu 
places  both  the  marsupials  and  the  monotremata ;  so  that 
he  makes  man  as  distinct  from  all  other  mammals  as  are 
these  two  latter  groups  conjoined.  This  view  has  not 
been  accepted,  as  far  as  I  am  aware,  by  any  naturalist 

*  Sec  the  very  interesting  article,  "  L'Instiuct  chez  les  Insects,"  by 
M.  George  Touchet,  'Revue  des  Deux  Mondes,'  Feb.  1870,  p.  682. 


Chap.  VI.]  AFFINITIES  AND  GENEALOGY.  181 

capable  of  forming  an  independent  judgment,  and  there- 
fore need  not  here  be  further  considered. 

We  can  understand  why  a  classification  founded  on 
any  single  character  or  organ — even  an  organ  so  wonder- 
fully complex  and  important  as  the  brain — or  on  the  high 
development  of  the  mental  faculties,  is  almost  sure  to 
prove  unsatisfactory.  This  principle  has  indeed  been  tried 
with  hymenopterous  insects  ;  but  when  thus  classed  by 
their  habits  or  instincts,  the  arrangement  proved  thor- 
oughly artificial.^  Classifications  may,  of  course,  be  based 
on  any  character  whatever,  as  on  size,  color,  or  the  ele- 
ment inhabited ;  but  naturalists  have  long  felt  a  profound 
conviction  that  there  is  a  natural  system.  This  system, 
it  is  now  generally  admitted,  must  be,  as  far  as  possible, 
genealogical  in  arrangement — that  is,  the  co-descendants 
of  the  same  form  must  be  kept  together  in  one  group,  sep- 
arate from  the  co-descendants  of  any  other  form  ;  but  if 
the  parent-forms  are  related,  so  will  be  their  descendants, 
and  the  two  groups  together  will  form  a  larger  group. 
The  amount  of  difference  between  tne  several  groups — 
that  is,  the  amount  of  modification  which  each  has  under- 
gone— will  be  expressed  by  such  terms  as  genera,  families, 
orders,  and  classes.  As  we  have  no  record  of  the  lines  of 
descent,  these  lines  can  be  discovered  only  by  observing 
the  degrees  of  resemblance  between  the  beings  which  are 
to  be  classed.  For  this  object  numerous  points  of  resem- 
blance are  of  much  more  importance  than  the  amount  of 
similarity  or  dissimilarity  in  a  few  points.  If  two  lan- 
guages were  found  to  resemble  each  other  in  a  multitude 
of  words  and  points  of  construction,  they  would  be  uni- 
versally recognized  as  having  sprung  from  a  common 
source,  notwithstanding  that  they  difiered  greatly  in  some 
few  words  or  points  of  construction.  But  with  organic 
beings  the  points  of  resemblance  must  not  consist  of 
3  Westwood,  'Modern  Class,  of  Insects,'  vol.  ii.  1840,  p.  87. 


182  THE   DESCENT   OF   MAN.  [Pakt  I. 

adaptations  to  similar  habits  of  life :  two  animals  may, 
for  instance,  have  had  their  whole  frames  modified  for 
living  in  the  water,  and  yet  they  will  not  be  brought  any 
nearer  to  each  other  in  the  natural  system.  Hence  we  can 
see  how  it  is  that  resemblances  in  unimportant  structures, 
in  useless  and  rudimentary  organs,  and  in  parts  not  as  yet 
full}'^  developed  or  functionally  active,  are  by  far  the  most 
serviceable  for  classification  ;  for  they  can  hardly  be  due 
to  adaptations  within  a  late  period  ;  and  thus  they  reveal 
the  old  lines  of  descent  or  of  true  aflinity. 

We  can  further  see  why  a  great  amount  of  modifica- 
tion in  some  one  character  ought  not  to  lead  us  to  sepa- 
rate w^idely  any  two  organisms.  A  part  which  already 
differs  much  from  the  same  part  in  other  allied  forms  has 
already,  according  to  the  theory  of  evolution,  varied 
much ;  consequently  it  would  (as  long  as  the  organism 
remained  exposed  to  the  same  exciting  conditions)  be 
liable  to  further  variations  of  the  same  kind  ;  and  these, 
if  beneficial,  would  be  preserved,  and  thus  continually 
augmented.  In  many  cases  the  continued  development 
of  a  part,  for  instance,  of  the  beak  of  a  bird,  or  the  teeth 
of  a  mammal,  would  not  be  advantageous  to  the  species 
for  gaining  its  food,  or  for  any  other  object ;  but  with  man 
we  can  see  no  definite  limit,  as  far  as  advantage  is  con- 
cerned, to  the  continued  development  of  the  brain  and 
mental  faculties.  Therefore  in  determining  the  position 
of  man  in  the  natural  or  genealogical  system,  the  extreme 
development  of  his  brain  ought  not  to  outweigh  a  multi- 
tude of  resemblances  in  other  less  important  or  quite  un- 
important point?. 

The  greater  number  of  naturalists  who  have  taken 
into  consideration  the  Avhole  structure  of  man,  including 
his  mental  faculties,  have  followed  Blumenbach  and  Cu- 
vicr,  and  have  placed  man  in  a  separate  Order,  under  the 
title  of  the  Bimana,  and  therefore  on  an  equality  with  the 


Chap.  VI.]  AFFINITIES    AND   GENEALOGY.  183 

Orders  of  the  Quadrumana,  Carnivora,  etc.  Recently 
many  of  our  best  naturalists  have  I'ecurred  to  the  view 
first  propounded  by  Linnseus,  so  remarkable  for  his  sa- 
gacity, and  have  placed  man  in  the  same  Order  with  the 
Quadrumana,  under  the  title  of  the  Primates.  The  justice 
of  this  conclusion  will  be  admitted  if,  in  the  first  place, 
we  bear  in  mind  the  remarks  just  made  on  the  com])ara- 
tively  small  importance  for  classification  of  the  great  de- 
veloj)ment  of  the  brain  in  man;  bearing,  also,  in  mind 
that  the  strongly-marked  differences  between  the  skiills  of 
man  and  the  Quadrumana  (lately  insisted  upon  by  Bi- 
schoff,  Aeby,  and  others)  apparently  follow  from  their  dif- 
ferently-developed brains.  In  the  second  jalace,  we  must 
remember  that  nearly  all  the  other  and  more  important 
difierences  between  man  and  the  Quadrumana  are  mani- 
festly adaptive  in  their  nature,  and  relate  chiefly  to  the 
erect  position  of  man ;  such  as  the  structure  of  his  hand, 
foot,  and  pelvis,  the  curvature  of  his  spine,  and  the  po- 
sition of  his  head.  The  fiimily  of  seals  oflers  a  good  il- 
histration  of  the  small  importance  of  adaptive  characters 
for  classification.  These  animals  differ  from  all  other  Car- 
nivora in  the  form  of  their  bodies  and  in  the  structure  of 
their  limbs,  far  more  than  does  man  from  the  higher  apes ; 
yf'  .n  every  system,  from  tliat  of  Cuvier  to  the  most  re- 
cent one  by  Mr.  Flower,*  seals  are  ranked  as  a  mere  family 
in  the  Order  of  the  Carnivora.  If  man  had  not  been  his 
own  classifier,  he  would  never  have  thought  of  founding  a 
separate  order  for  his  own  reception. 

It  would  be  beyond  my  limits,  and  quite  beyond  my 
knowledge,  even  to  name  the  innumerable  points  of  struct- 
ure in  which  man  agrees  with  the  other  Primates.  Our 
great  anatomist  and  philosopher.  Prof.  Huxley,  has  fully 
discussed  this  subject,^  and  has  come  to  the  conclusion 

4  'Proc.  Zoolog.  Soc'  1809,  p.  4. 

* '  Evidence  as  to  Man's  Place  in  Nature,'  18tJ8,  p.  TO,  et  pa.'ishn. 


184  THE   DESCENT   OF  MAN.  [Pap.t  I. 

that  man  in  all  parts  of  his  organization  differs  less  from 
the  higher  ajies,  than  these  do  from  the  lower  members  of 
the  same  group.  Consequently  there  "  is  no  justification 
for  placing  man  in  a  distinct  order." 

In  an  early  part  of  this  volume  I  brought  forward 
various  facts,  showing  how  closely  man  agrees  in  consti- 
tution with  the  higher  mammals ;  and  this  agreement,  no 
doubt,  depends  on  our  close  similarity  in  minute  structure 
and  chemical  composition.  I  gave,  as  instances,  our  lia- 
bility to  the  same  diseases,  and  to  the  attacks  of  allied 
parasites ;  our  tastes  in  common  for  the  same  stimulants, 
and  the  similar  effects  thus  produced,  as  well  as  by  various 
drugs ;  and  other  such  facts. 

As  small  unimportant  points  of  resemblance  between 
man  and  the  higher  apes  are  not  commonly  noticed  in 
systematic  works,  and  as,  when  numerous,  they  clearly 
reveal  our  relationship,  I  will  sjjccify  a  few  such  points. 
The  relative  positions  of  the  features  are  manifestly  the 
same  in  man  and  the  Quadrumana ;  and  the  various  emo- 
tions are  displayed  by  nearly  similar  movements  of  the 
muscles  and  skin,  chiefly  above  the  eyebrows  and  round 
the  mouth.  Some  few  expressions  are,  indeed,  almost  the 
same,  as  in  the  weeping  of  certain  kinds  of  monkeys,  and 
in  the  laughing  noise  made  by  others,  during  which  the 
corners  of  the  mouth  are  drawn  backward,  and  the  lower 
eyelids  wrinkled.  The  external  ears  are  curiously  alike.  In 
man  the  nose  is  much  more  prominent  than  in  most  mon- 
keys ;  but  we  may  trace  the  commencement  of  an  aquiline 
curvature  in  the  nose  of  the  Iloolock  Gibbon  ;  and  this  in 
the  Semnopithecus  nasica  is  carried  to  a  ridiculous  extreme. 

The  faces  of  many  monkeys  are  ornamented  with 
beards,  whiskers,  or  mustaches.  The  hair  on  the  head 
grows  to  a  great  length  in  some  species  of  Semnopithe- 
cus ; '  and  in  the  Bonnet  monkey  (Macacus  radiatus)  it 
« Isid.  Geoffroy,  '  Hist.  Nat.  Gen.'  torn.  ii.  1859,  p.  217. 


Chap.  VI.]  AFFINITIES   AND   GENEALOGY.  185 

radiates  from  a  point  on  the  crown,  with  a  parting  down 
the  middle,  as  in  man.  It  is  commonly  said  that  the  fore- 
head gives  to  man  his  noble  and  intellectual  appearance ; 
but  the  thick  hair  on  the  head  of  the  Bonnet  monkey  ter- 
minates abruptly  downward,  and  is  succeeded  by  such 
short  and  fine  hair,  or  down,  that  at  a  little  distance  the 
forehead,  with  the  exception  of  the  eyebrows,  appears 
quite  naked.  It  has  been  erroneously  asserted  that  eye- 
brows are  not  pi'esent  in  any  monkey.  In  the  species  just 
named  the  degree  of  nakedness  of  the  forehead  differs  in 
different  individuals,  and  Eschricht  states ''  that  in  our 
children  the  limit  between  the  hairy  scalp  and  the  naked 
foi'ehead  is  sometimes  not  well  defined ;  so  that  here  we 
seem  to  have  a  trifling  case  of  reversion  to  a  progenitor, 
in  whom  the  forehead  had  not  as  yet  become  quite  naked. 
It  is  well  known  that  the  hair  on  our  arms  tends  to 
converge  from  above  and  below  to  a  point  at  the  elbow. 
This  curious  arrangement,  so  unlike  that  in  most  of  the 
lower  mammals,  is  common  to  the  gorilla,  chimpanzee, 
orang,  some  species  of  Hylobates,  and  even  to  some  few 
American  monkeys.  But  in  Hylohates  agilis  the  hair 
on  the  forearm  is  directed  downward  or  toward  the  wrist 
in  the  ordinary  manner ;  and  in  IL  lar  it  is  nearly  erect, 
with  only  a  very  slight  forvv'ard  inclination ;  so  that  in 
this  latter  species  it  is  in  a  transitional  state.  It  can 
hardly  be  doubted  that  with  most  mammals  the  thickness 
of  the  hair  and  its  direction  on  the  back  is  adapted  to 
throw  ofl:'  the  rain ;  even  the  transverse  hairs  on  the  fore- 
legs of  a  dog  may  serve  for  this  end  when  he  is  coiled  up 
asleep.  Mr.  Wallace  remarks  that  the  convergence  of  the 
hair  toward  the  elbow  on  the  arms  of  the  orang  (whose 
habits  he  has  so  carefully  studied)  serves  to  throw  off  the 
rain,  when,  as  is  the  custom  of  this  animal,  the  arms  are 

■"  "  Ueber  die  Richtung  der  Ilaare,"  etc.,  Miiller'a  '  Archiv  fiir  Anat 
up.d  rhys.'  1837,  s.  51. 
9 


186  THE   DESCENT   OF  MAN.  [Part  I. 

bent,  with  the  hands  clasped  round  a  branch  or  over  its 
own  liead.  We  shoidd,  however,  bear  in  mind  tliat  the 
attitude  of  an  animal  may  perhaps  be  in  part  determined 
by  the  direction  of  tlie  hair ;  and  not  the  direction  of  the 
hair  by  the  attitude.  If  the  above  explanation  is  correct 
in  the  case  of  the  orang,  the  hair  on  our  forearms  offers  a 
curious  record  of  our  former  state ;  for  no  one  supposes  that 
it  is  now  of  any  use  in  throwing  off  the  rain,  nor  in  our  pres- 
ent erect  condition  is  it  properly  directed  for  this  purpose. 

It  would,  however,  be  rash  to  trust  too  much  to  the 
principle  of  adaptation  in  regard  to  the  direction  of  the 
hair  in  man  or  his  early  progenitors ;  for  it  is  impossible 
to  study  the  figures  given  by  Eschricht  of  the  arrange- 
ment of  the  hair  on  the  human  foetus  (this  being  the  same 
as  in  the  adult)  and  not  agree  with  this  excellent  observer 
that  other  and  more  comj^lex  causes  have  intervened. 
The  points  of  convergence  seem  to  stand  in  some  relation 
to  those  points  in  the  embryo  which  are  last  closed  in 
during  development.  There  appears,  also,  to  exist  some 
relation  between  the  arrangement  of  the  hair  on  the  limbs, 
and  the  course  of  the  medullary  arteries.® 

It  must  not  be  supposed  that  the  resemblances  be- 
tween man  and  certain  apes  in  the  above  and  many  other 
points — such  as  in  having  a  naked  forehead,  long  tresses 
on  the  head,  etc. — are  all  necessarily  the  result  of  un- 
broken inheritance  from  a  common  progenitor  thus  charac- 
terized, or  of  subsequent  reversion.  JMany  of  these  resem- 
blances are  more  probably  due  to  analogous  variation, 
which  follows,  as  I  have  elsewhere  attempted  to  show,* 

*  On  the  hair  iu  ITjlobatcs,  see  '  Nat.  Hist,  of  Mammals,'  by  C.  L. 
Martin,  18-11,  p.  415.  Also,  Isid.  Gcoffroy  on  the  American  monkeys  and 
oiher  kinds,  'Hist.  Nat.  Gen.' vol.  ii.  1859,  pp.  216,  213.  Eschricht,  ibid, 
s.  46,  55,  61.  Owen, 'Anat.  of  Vertebrates,'  vol.  iii.  p.  619.  Wallace, 
'Contributions  to  the  Theory  of  Natural  Selection,'  1870,  p.  344. 

8  'Origin  of  Species,'  5th  edit.  1869,  p.  194.  '  The  Variation  of  Ani- 
mals and  IMants  under  Domesiioatirm,'  vol  ii.  1868,  p.  348. 


I 


CiiAP.  YI.]  AFFINITIES   AXD   GENEALOGY.  187 

frona  co-clesccnded  organisms  Iiaviiig  a  similar  constitution 
and  having  been  acted  on  by  similar  causes  inducing 
variability.  Witli  respect  to  the  similar  direction  of  the 
hair  on  the  forearms  of  man  and  certain  monkeys,  as  this 
character  is  common  to  almost  all  the  anthropomorphous 
apes,  it  may  probably  be  attributed  to  inheritance ;  but 
not  certainly  so,  as  some  very  distinct  American  monkeys 
are  thus  characterized.  The  same  remark  is  applicable  to 
the  tailless  condition  of  man  ;  for  the  tail  is  absent  in  all 
the  anthropomorphous  apes.  Nevertheless  this  character 
cannot  with  certainty  be  attributed  to  inheritance,  as  the 
tail,  though  not  absent,  is  rudimentary  in  several  other 
Old  "World  and  in  some  'New  "World  species,  and  is  quite 
absent  in  several  species  belonging  to  the  allied  group  of 
Lemurs. 

Although,  as  we  have  now  seen,  man  has  no  just  right 
to  form  a  separate  Order  for  his  own  reception,  he  may 
perhaps  claim  a  distinct  Sub-oi-der  or  Family.  Prof.  Hux- 
ley, in  his  last  work,"  divides  the  Primates  into  three  Sub- 
orders :  namely,  the  Anthropidae  with  man  alone,  the 
Simiadro  including  monkeys  of  all  kinds,  and  the  Lemu- 
rida)  with  the  diversified  genera  of  lemurs.  As  far  as  dif- 
ferences in  certain  important  points  of  structure  are  con- 
cerned, man  may  no  doubt  rightly  claim  the  rank  of  a 
Sub-order ;  and  this  rank  is  too  low,  if  we  look  chiefly  to 
his  mental  faculties.  Nevertheless,  under  a  genealogical 
point  of  view  it  appears  that  this  rank  is  too  high,  and 
that  man  ought  to  form  merely  a  Family,  or  possibly  even 
only  a  Sub-family.  If  we  imagine  three  lines  of  descent 
proceeding  from  a  common  source,  it  is  quite  conceivable 
that  two  of  them  might  after  the  lapse  of  ages  be  so 
slightly  changed  as  still  to  remain  as  species  of  the  same 
genus ;  while  the  third  line  might  become  so  greatly 
modified  as  to  deserve  to  rank  as  a  distinct  Sub-family, 

'"  '  An  Inti-odiiction  to  the  Classification  of  Animals,'  1869,  p.  99. 


188  THE   DESCENT   OF   MAX.  [Paut  I. 

Family,  or  even  Order.  But  in  this  ease  it  is  almost  cer- 
tain that  the  third  line  would  still  retain  through  inheri- 
tance numerous  small  points  of  resemblance  with  the 
other  two  lines.  Here,  then,  would  occur  the  difficulty,  at 
present  insoluble,  how  much  weight  we  ought  to  assign  in 
our  classifications  to  strongly-marked  differences  in  some 
few  points — that  is,  to  the  amount  of  modification  under- 
gone ;  and  how  much  to  close  resemblance  in  numerous 
unimportant  points,  as  indicating  the  lines  of  descent  or 
genealogy.  The  former  alternative  is  the  most  obvious, 
and  perhaps  the  safest,  though  the  latter  ajipeai-s  the  most 
correct  as  giving  a  truly  natural  classification. 

To  form  a  judgment  on  this  head,  with  reference  to 
man  we  must  glance  at  the  classification  of  the  SimiadoD. 
This  family  is  divided  by  almost  all  naturalists  into  the 
Catarhine  group,  or  Old  World  monkeys,  all  of  which  are 
characterized  (as  their  name  expresses)  by  the  peculiar 
structure  of  their  nostrils  and  by  having  four  premolars 
in  each  jaw  ;  and  into  the  Platyrhiue  group  or  Xew  World 
monkeys  (including  two  very  distinct  sub-groups),  all  of 
which  are  characterized  by  differently-constructed  nostrils 
and  by  having  six  premolars  in  each  jaw.  Some  other 
small  diftercnces  might  be  mentioned.  Xow  man  xiuques- 
tionably  belongs  in  his  dentition,  in  the  structure  of  his 
nostrils,  and  some  other  resjiects,  to  the  Catarhine  or  Old 
World  division  ;  nor  does  he  resemble  the  Platyrhines 
more  closely  than  the  Catarhines  in  any  characters,  ex- 
cepting in  a  few  of  not  much  importance  and  apparently 
of  an  adaj^tive  nature.  Therefore  it  would  be  against  all 
probability  to  suppose  that  some  ancient  New  World 
species  had  varied,  and  had  thus  produced  a  man-like 
creature  with  all  the  distinctive  characters  proper  to  the 
Old  World  division;  losing  at  the  same  time  all  its  own 
distinctive  characters.  There  can  consequently  hardly  be 
a  doubt  that  man  is  an  offshoot  from  the  Old  World  Sim- 


Chap.  YI.]  AFFINITIES   AND   GENEALOGY.  180 

ian  stem ;  and  that,  under  a  genealogical  point  of  vie^v, 
lie  must  be  classed  with  the  Catarliine  division." 

The  anthropomorphous  apes,  namely  the  gorilla,  chim- 
panzee, orang,  and  hylobates,  are  separated  as  a  distinct 
sub-group  from  the  other  Old  World  monkeys  by  most 
naturalists.  I  am  aware  that  Gratiolet,  relying  on  the 
structure  of  the  brain,  does  not  admit  the  existence  of  this 
sub-group,  and  no  doubt  it  is  a  broken  one ;  thus  the  orang, 
as  Mr.  St.  G.  Mivart  remarks,'^  "  is  one  of  the  most  peculiar 
and  aberrant  forms  to  be  found  in  the  order."  The  re- 
maining, non-anthropomorphous,  Old  World  monkeys,  are 
again  divided  by  some  naturalists  into  two  or  three 
smaller  sub-groups ;  the  genus  Semnopithecus,  Avith  its 
peculiar  sacculated  stomach,  being  the  type  of  one  such 
sub-group.  But  it  appears  from  M.  Gaudry's  wonderful  dis- 
coveries in  Attica,  that  during  the  Miocene  period  a  form 
existed  there,  which  connected  Semnopithecus  and  Maca- 
cus ;  and  this  probably  illustrates  the  manner  in  which 
the  other  and  higher  groups  were  once  blended  together. 

K  the  anthropomorphous  apes  be  admitted  to  form  a 
natural  sub-group,  then  as  man  agrees  with  them,  not 
only  in  all  those  characters  which  he  possesses  in  common 
with  the  whole  Catarhine  group,  but  in  other  peculiar 
characters,  su^ch  as  the  absence  of  a  tail  and  of  callosities 
and  in  general  appearance,  we  may  infer  tliat  some  ancient 
member  of  the  anthropomorphous  sub-group  gave  birth 
to  man.  It  is  not  probable  that  a  member  of  one  of  the 
other  lower  sub-groups  should,  through  the  law  of  analo- 
gous variation,  have   given   rise   to  a  man-like  creature, 

''  This  is  nearly  the  same  classification  as  that  provisionally  adopted 
by  Mr.  St.  George  Mivart  ('  Transact.  Philosopli.  Soc'  1867,  p.  300), 
M'ho,  after  separating  the  LemuridaB,  divides  the  remainder  of  the 
Primates  into  the  Hominidfe,  the  Simiadtc  answering  to  the  Catarhines, 
the  Cebidoe,  and  the  Hapalidae — these  two  latter  groups  answering  to  the 
Platyrhines. 

'2  'Transact.  Zoolog.  Soc'  vol.  vi.  1867,  p.  214. 


190  THE   DESCENT   OF  MAX.  [Part  I. 

resembling  the  higher  anthropomorphous  apes  in  so  many 
respects.  No  doubt  man,  in  comparison  with  most  of  his 
allies,  has  undergone  an  extraordinary  amount  of  modiii- 
cation,  chiefly  in  consequence  of  his  greatly-developed 
brain  and  erect  position ;  nevertheless,  we  should  bear  in 
mind  that  he  "  is  but  one  of  several  exceptional  forms  of 
Primates." '' 

Every  naturalist,  who  believes  in  the  principle  of 
evolution,  will  grant  that  the  two  main  divisions  of  the 
Simiada^,  namely  the  Catarhine  and  Platyrhine  monkeys, 
with  their  sub-groups,  have  all  proceeded  from  some  one 
extremely  ancient  progenitor.  The  early  descendants  of 
this  progenitor,  before  they  had  diverged  to  any  con- 
siderable extent  from  each  other,  would  still  haA'e  formed 
a  single  natural  group ;  but  some  of  the  species  or  incipi- 
ent genera  would  have  already  begun  to  indicate  by  their 
diver<xin<T  characters  the  future  distinctive  marks  of  the 
Catarhine  and  Platyrhine  divisions.  Hence  the  members 
of  this  supposed  ancient  group  would  not  have  been  so 
uniform  in  their  dentition  or  in  the  structure  of  their 
nostrils,  as  are  the  existing  Catarhine  monkeys  in  one  way 
and  the  Platyrhines  in  another  way,  but  would  have 
resembled  in  this  respect  the  allied  Lcmurida?  which  differ 
greatly  from  each  other  in  the  form  of  their  muzzles,"  and 
to  an  extraordinary  degree  in  their  dentition. 

The  Catarhine  and  Platyi-hino  monkeys  agree  in  a 
multitude  of  characters,  as  is  shown  by  their  unques- 
tionably belonging  to  one  and  the  same  order.  The  many 
characters  v/hicli  they  possess  in  common  can  hardly 
have  been  independently  acquired  by  so  many  distinct 
species ;  so  that  these  characters  must  have  been  inherited. 
But  an  ancient  form  Avhich   possessed  many   characters 

'3  Mr.  St.  G.  Mivai-t,  'Transact.  Tbil.  Soc'  1867,  p.  410. 
'*  Messrs.  Murie  and  Mivart  oa  the  Lcmuroidca,  '  Transact.  Zoolog. 
Soc'  vol.  vii.  1869,  p.  5. 


Chap.  VI.]  AFFINITIES  AND   GENEALOGY.  191 

common  to  llie  Catarhine  and  Platyrhino  monkeys,  and 
others  in  an  intermediate  condition,  and  some  few  perhaps 
distinct  from  those  now  present  in  either  group,  would 
undoubtedly  have  been  ranked,  if  seen  by  a  naturalist,  as 
an  ape  or  monkey.  And  as  man  under  a  genealogical 
point  of  view  belongs  to  the  Catarhine  or  Old  World 
stock,  we  must  conclude,  however  much  the  conclusion 
may  revolt  our  pride,  that  our  early  pi-ogenitors  would 
have  been  properly  thus  designated.'^  But  we  must  not 
fall  into  the  error  of  supposing  that  the  early  progenitor  of 
the  whole  Simian  stock,  including  man,  was  identical  with, 
or  even  closely  resembled,  any  existing  ape  or  monkey. 

Oil  the  BirthplacQ  and  Antiquity  of  JIan. — We  are 
naturally  led  to  inquire  where  was  the  birthplace  of  man 
at  that  stage  of  descent  v/hen  our  progenitors  divei'ged 
from  the  Catarhine  stock.  The  fact  that  they  belonged 
to  this  stock  clearly  shows  that  they  inhabited  the  Old 
World ;  but  not  Australia  nor  any  oceanic  island,  as  we 
may  infer  from  the  laws  of  geographical  distribution.  In 
each  great  region  of  the  world  the  living  mammals  are 
closely  related  to  the  extinct  species  of  the  same  region. 
It  is  therefore  probable  that  Africa  was  formerly  inhab- 
ited by  extinct  apes  closely  allied  to  the  gorilla  and  chim- 
panzee ;  and  as  these  two  species  are  now  man's  nearest 
allies,  it  is  somewhat  more  probable  that  our  early  pro- 
genitors lived  on.  the  African  Continent  than  elsewhere. 
But  it  is  useless  to  speculate  on  this  subject,  for  an  ape 
nearly  as  large  as  a  man,  namely,  the  Dryopithecus  of 
Lartet,  which  was  closely  allied  to  the  anthropomorphous 

'5  Ilackcl  has  come  to  this  same  conclusion.  See  '  Ucber  die  Ent- 
stehung  des  Menschengoschlechts,'  in  Virchow's  '  Sammlung.  gemein. 
wissen.  Vortrage,'  1868,  s.  61.  Also  his  'Natiirliche  Schopfungs- 
gcschichte,'  1868,  in  which  he  gives  in  detail  his  views  on  the  genealogy 
of  man. 


192  THE   DESCENT   OF   MAN.  [Part  I. 

ITylobates,  existed  in  Europe  during  the  Upper  Miocene 
period ;  and  since  so  remote  a  period  the  earth  has  cer- 
tainly undergone  many  great  revohitions,  and  there  has 
been  ample  time  for  migration  on  the  largest  scale. 

At  the  period  and  place,  whenever  and  wherever  it 
may  have  been,  when  man  first  lost  his  hairy  covering,  he 
probably  inhabited  a  hot  country ;  and  this  v.'ould  have 
been  favorable  for  a  frugiferous  diet,  on  which,  judging 
from  analogy,  he  subsisted.  We  are  far  from  knowing 
liow  long  ago  it  was  when  man  first  diverged  from  the 
Catarhine  stock ;  but  this  may  have  occurred  at  an  epoch 
as  remote  as  the  Eocene  period ;  for  the  higher  apes  had 
diverged  from  the  lower  apes  as  early  as  the  Upper  Mio- 
cene period,  as  shown  by  the  existence  of  the  Dryopithc- 
cus.  We  are  also  quite  ignorant  at  how  rapid  a  rate  oi-- 
ganisms,  whether  high  or  low  in  the  scale,  may  under 
favorable  circumstances  be  modified :  we  know,  however, 
that  some  have  retained  the  same  form  during  an  enor- 
mous lapse  of  time.  From  what  we  see  going  on  under 
domestication,  we  learn  that  within  the  same  period  some 
of  the  co-descendants  of  the  same  species  may  be  not  at 
all  changed,  some  a  little,  and  some  greatly  changed. 
Thus  it  may  have  been  with  man,  who  has  undergone  a 
great  amount  of  modification  in  certain  characters  in  com- 
parison witli  the  higher  apes. 

The  great  break  in  the  organic  chain  betvreen  man  and 
his  nearest  allies,  which  cannot  be  bridged  over  by  any 
extinct  or  living  species,  has  often  been  advanced  as  a 
grave  objection  to  the  belief  that  man  is  descended  from 
some  lower  form ;  but  tliis  objection  will  not  appear  of 
much  weight  to  those  Avho,  convinced  by  general  reasons, 
believe  in  the  general  principle  of  evolution.  Breaks  in- 
cessantly occur  in  all  parts  of  the  scries,  some  being  wide, 
sharp,  and  defined,  others  less  so  in  various  degrees ;  as 
between  the  orana;  and  its  nearest  allies — between  tlio 


CnAP.  VI.]  AFFINITIES   AND   GENEALOGY.  193 

Tarsius  and  the  othei-  Lemuridaj — between  the  elephant 
and  in  a  more  striking  manner  between  the  Ornithorhyn- 
chus  or  Echidna,  and  other  mammals.  But  all  these 
breaks  depend  merely  on  the  number  of  related  forms 
which  have  become  extinct.  At  some  future  period,  not 
very  distant  as  measured  by  centuries,  the  civilized  races 
of  man  will  almost  certainly  exterminate  and  replace 
throughout  the  world  the  savage  races.  At  the  same 
time  the  anthropomorphous  apes,  as  Prof.  Schaaft'hauscn 
has  remai'ked,'"  will  no  doubt  be  exterminated.  The 
break  v>^ill  then  be  rendered  wider,  for  it  will  intervene 
between  man  in  a  more  civilized  state,  as  we  may  hope, 
than  the  Caucasian,  and  some  ape  as  low  as  a  baboon,  in- 
stead of  as  at  present  between  the  negro  or  Australian 
and  the  gorilla. 

With  respect  to  the  absence  of  fossil  remains,  serving 
to  connect  man  with  his  ape-like  progenitors,  no  one  will 
lay  much  stress  on  this  fact,  who  will  read  Sir  C.  Lyell's 
discussion,"  in  which  he  shows  that  in  all  the  vertebrate 
classes  the  discovery  of  fossil  remains  has  been  an  ex- 
tremely slow  and  fortuitous  process.  ISTor  should  it  be 
forgotten  that  those  regions  which  are  the  most  likely  to 
afford  remains  connecting  man  with  some  extinct  ape-like 
creature,  have  not  as  yet  been  searched  by  geologists. 

Lower  Stages  in  the  Genealogy  of  Man, — We  have 
seen  that  man  appears  to  have  diverged  from  the  Cata- 
rhine  or  Old  World  division  of  the  Simiad??,  after  these 
had  diverged  from  the  ISTew  World  division.  We  will 
now  endeavor  to  follow  the  more  remote  traces  of  his 
genealogy,  trusting  in  the  first  place  to  the  mutual  affini- 
ties  between  the  various  classes  and  orders,  with  some 

i«  'Anthropological  Review,'  April,  1867,  p.  236. 
"'Elements  of  Geology,'  1865,  pp.   583-585.     'Antiquity  of  Man,' 
1803,  p.  145. 


194  THE   DESCENT   OF   MAN.  [Part  I. 

slight  aid  from  the  periods,  as  far  as  ascertained,  of  their 
successive  appearance  on  tlic  earth.  The  Lemuridao  stand 
below  and  close  to  the  Simiada?,  constituting  a  very  dis- 
tinct family  of  the  Primates,  or,  according  to  Ililckel,  a 
distinct  Order.  This  group  is  diversified  and  broken  to 
an  extraordinary  degree,  and  includes  many  aberrant 
forms.  It  has,  therefore,  probably  sufiered  much  extinc- 
tion. Most  of  the  remnants  survive  on  islands,  namely,  in 
Madagascar  and  in  the  islands  of  the  Malayan  archipelago, 
where  they  have  not  been  exposed  to  such  severe  compe- 
tition as  they  would  have  been  on  well-stocked  continents. 
This  group  likewise  presents  many  gradations,  leading,  as 
Iluxlcy  remarks,"  "  insensibly  from  the  ci'own  and  sum- 
mit of  the  animal  creation  down  to  creatures  from  which 
there  is  but  a  stej),  as  it  seems,  to  the  lowest,  smallest, 
and  least  intelligent  of  the  placental  mammalia."  From 
these  various  considerations  it  is  probable  that  the  Simiadte 
were  originally  developed  from  the  progenitors  of  the  ex- 
isting Lemurida? ;  and  these  in  their  turn  from  forms  stand- 
ing very  low  in  the  mammalian  series. 

The  Marsupials  stand  in  many  important  characters 
below  the  placental  mammals.  They  appeared  at  an 
earlier  geological  period,  and  their  range  was  formerly 
much  more  extensive  than  what  it  now  is.  Hence  the 
Placcntata  are  generally  supposed  to  have  been  derived 
from  the  Implacentata  or  Marsupials  ;  not,  however,  from 
fonns  closely  like  the  existing  Marsiipials,  but  from  their 
early  progenitors.  The  Monotrcmata  are  plainly  allied  to 
the  Marsupials  ;  forming  a  third  and  still  lower  division  in 
tlie  great  mammalian  series.  They  are  represented  at  the 
present  day  solely  by  the  Ornithorhynchus  and  Echidna ; 
and  these  two  forms  ma}'  be  safely  considered  as  relics  of 
a  much  larger  group  which  have  been  preserved  in  Austra- 
lia through  some  favorable  concurrence  of  circumstances. 

'8  '  Man's  riacc  in  Nature,'  p.  105. 


Chap.  VI.]  AFFINITIES  AND   GENEALOGY  195 

The  Monotremata  are  eminently  interesting,  as  in  several 
important  points  of  structure  they  lead  toward  the  class 
of  reptiles 

In  attempting  to  trace  the  genealogy  of  the  Mam- 
malia, and  therefore  of  man,  lower  down  in  the  series,  we 
become  involved  in  greater  and  gi'eater  obscurity.  He 
who  wishes  to  see  what  ingenuity  and  knowledge  can 
effect,  may  consult  Prof.  Hackel's  vv^orks.'"  I  will  con- 
tent myself  with  a  few  general  remarks.  Every  evolu- 
tionist will  admit  that  the  five  great  vertebrate  classes, 
namely,  mammals,  birds,  reptiles,  amphibians,  and  fishes, 
are  all  descended  from  some  one  prototype  ;  for  they  have 
much  in  common,  especially  during  their  embryonic  state. 
As  the  class  of  fishes  is  the  most  lowly  organized  and  ap- 
peared before  the  others,  we  may  conclude  that  all  the 
members  of  the  vertebrate  kingdom  ai"e  derived  from  some 
fish-like  animal,  less  highly  organized  than  any  as  yet 
found  in  the  lowest  known  formations.  The  belief  that 
animals  so  distinct  as  a  monkey  or  elephant  and  a  hum- 
ming-bird, a  snake,  frog,  and  fish,  etc.,  could  all  have 
sprung  from  the  same  parents,  will  appear  monstrous  to 
those  who  have  not  attended  to  the  recent  progress  of 
natural  history.  For  this  belief  implies  the  former  ex- 
istence of  links  closely  binding  together  all  these  forms, 
now  so  utterly  unlike. 

Nevertheless,  it  is  certain  that  groups  of  animals  have 
existed,  or  do  now  exist,  which  serve  to  connect  more  or 
less  closely  the  several  great  vertebrate  classes.    We  have 

^'  Elaborate  tables  are  giveu  iu  his  '  Generelle  Morphologie '  (B.  ii. 
s.  cliii.  and  s.  425) ;  and  with  more  especial  reference  to  man  in  his 
'Natiirliche  Schopfungsgeschichte,'  1S68.  Prof.  Huxley,  in  reviewing 
this  latter  work  ('The  Academy,' 1869,  p.  42)  says  that  he  considers 
the  phylum  or  lines  of  descent  of  the  Vertebrata  to  be  admirably  dis- 
cussed by  Hackel,  although  he  differs  on  some  points.  He  expresses, 
also,  his  high  estimate  of  the  value  of  the  general  tenor  and  spirit  of  the 
whole  work. 


196  THE  DESCENT  OF  MAN.  [Part  I. 

seeu  that  the  Ornitliorliynclius  graduates  toward  reptiles ; 
and  Prof.  Huxley  lias  made  the  rcmarkahle  discovery, 
confirmed  by  Mr.  Cope  and  others,  that  the  old  Dinosaii- 
rians  are  intermediate  jn  many  important  respects  between 
certain  reptiles  and  certain  birds — the  latter  consisting  of 
the  'ostrich-tribe  (itself  evidently  a  widely-diffused  rem- 
nant of  a  larger  group)  and  of  the  Archeopteryx,  that 
strange  Secondary  bird  having  a  long  tail  like  that  of  the 
lizard.  Again,  according  to  Prof  Owen,""  the  Ichthy- 
osaurians — great  sea-lizards  furnislied  with  paddles — pre- 
sent many  afiinities  with  fishes,  or  rather,  according  to 
Huxley,  with  amphibians.  This  latter  class  (including  in 
its  highest  division  frogs  and  toads)  is  plainly  allied  to 
the  Ganoid  fishes.  These  latter  fishes  swarined  during 
the  earlier  geological  periods,  and  were  constructed  on 
what  is  called  a  highly-generalized  ty|>e,  that  is,  they  pre- 
sented diversified  affinities  with  other  groups  of  organisms. 
The  amphibians  and  fishes  are  also  so  closely  united  by 
the  Lepidosiren,  that  naturalists  long  disputed  in  which 
of  these  two  classes  it  ought  to  be  placed.  The  Lepido- 
siren and  some  few  Ganoid  fishes  have  been  preserved 
from  utter  extinction  by  inhabiting  our  rivers,  which  are 
harbors  of  refuge,  bearing  the  same  relation  to  the  great 
waters  of  the  ocean  that  islands  bear  to  continents. 

Lastly,  one  single  member  of  the  immense  and  diver- 
sified class  of  fishes,  namely,  the  lancelct  or  amphioxus,  is 
so  different  from  all  other  fishes,  that  Ilackel  maintains 
that  it  ought  to  form  a  distinct  class  in  the  vertebrate 
kingdom.  This  fish  is  remarkable  for  its  negative  charac- 
ters ;  it  can  hardly  be  said  to  possess  a  brain,  vertebral  col- 
umn, or  heart,  etc. ;  so  that  it  was  classed  by  the  older 
naturalists  among  the  womis.  Many  years  ago  Prof 
Goodsir  j^orceived  that  the  lancelet  presented  some  affini- 
ties with  the  Ascidians,  which  are  invertebrate,  hermaphro- 

•0  Talicontology,'  1800,  p.  lO.). 


Chap.  VI.]  AFFINITIES  AND   GENEALOGY.  197 

elite,  marine  creatures  permanently  attached  to  a  support. 
They  hardly  appear  like  animals,  and  consist  of  a  simple, 
tough,  leathery  sack,  with  two  small  projecting  orifices. 
They  belong  to  the  Molluscoida  of  Huxley — a  lower  di- 
vision of  the  great  kingdom  of  the  Mollusca;  but  they 
have  recently  been  placed  by  some  naturalists  among  the 
Vermes  or  worms.  Their  larvas  somewhat  resemble  tad- 
poles in  shape,^^  and  have  the  power  of  swimming  freely 
about.  Some  observations  lately  made  by  M.  Kowa- 
levsky,"'  since  confirmed  by  Prof.  Kuppfer,  will  form  a 
discovery  of  extraordinary  interest,  if  still  further  ex- 
tended, as  I  hear  from  M.  Kowalevsky  in  Naj^les  he  has 
now  effected.  The  discovery  is  that  the  larvae  of  As- 
cidians  are  related  to  the  Vertebrata,  in  then-  manner  of 
development,  in  the  relative  position  of  the  nervous  sys- 
tem, and  in  possessing  a  structure  closely  like  the  chorda 
dorsalis  of  vertebrate  animals.  It  thus  appears,  if  we 
may  rely  on  embryology,  which  has  always  proved  the 
safest  guide  in  classification,  that  we  have  at  last  gained 
a  clew  to  the  source  whence  the  Vertebrata  have  been  de- 
rived. We  should  thus  be  justified  in  believing  that  at 
an  extremely  remote  period  a  group  of  animals  existed, 
resembling  in  many  respects  the  larvaa  of  our  present  As- 
cidians,  which  diverged  into  two  great  branches — the  one 
retrograding  in  development  and  producing  the  present 

^^  I  had  the  satisfaction  of  seeing,  at  tha  Falkland  Islands,  in  April, 
1833,  and  therefore  some  years  before  any  other  naturalist,  the  locomo- 
tive larvos  of  a  compound  Ascidian,  closely  allied  to,  but  apparently  gen- 
erically  distinct  from,  Synoicum.  The  tail  was  about  five  times  as  long 
as  the  oblong  head,  and  terminated  in  a  very  fine  filament.  It  was 
plainly  divided,  as  sketched  by  me  under  a  simple  microscope,  by  trans- 
verse opaque  partitions,  which  I  presume  represent  the  great  cells  figured 
by  Kowalevsky.  At  an  early  stage  of  development  the  tail  was  closely 
coiled  round  the  head  of  the  larva. 

2^  '  Memoires  de  I'Acad.  des  Sciences  de  St.  Petersbourg,'  torn.  x.  No. 
15,  1866. 


198  THE   DESCENT   OF   MAN.  [Part  I. 

class  of  Ascidians,  tlie  other  rising  to  the  crowu  and  summit 
of  the  animal  kingdom  by  giving  birth  to  the  Vertebrata. 

Vie  have  thus  far  endeavored  rudely  to  trace  the 
genealogy  of  the  Vertebrata  by  the  aid  of  their  mutual 
affinities.  We  will  now  look  to  man  as  he  exists ;  and  we 
shall,  I  think,  be  able  partially  to  restore  during  successive 
periods,  but  not  in  due  order  of  time,  the  structure  of  our 
early  progenitors.  This  can  be  effected  by  means  of  the 
rudiments  which  man  still  retains,  by  the  characters  Avhich 
occasionally  make  their  appearance  in  him  through  rever- 
sion, and  by  the  aid  of  the  principles  of  morphology 
and  embryology.  The  various  facts,  to  which  I  shall  here 
allude,  have  been  given  in  the  previous  chapters.  The 
early  jDrogenitors  of  man  were  no  doubt  once  covered  with 
hail-,  both  sexes  having  beards ;  their  ears  were  pointed 
and  capable  of  movement ;  and  their  bodies  were  provided 
with  a  tail,  having  the  proper  muscles.  Their  limbs 
and  bodies  were  also  acted  on  by  many  muscles  which 
now  only  occasionally  reappear,  but  are  nonnally  present  in 
the  Qnadruniana.  The  great  artery  and  nerve  of  the  hu- 
merus ran  through  a  supra-condyloid  foramen.  At  this  or 
some  earlier  period,  the  intestine  gave  forth  a  much  lai'ger 
diverticulum  or  crocum  than  that  now  existing.  The  foot, 
judging  from  the  condition  of  the  great-toe  in  the  foetus, 
was  then  prehensile  ;  and  our  progenitors,  no  doubt,  were 
arboreal  in  their  habits,  frequenting  some  warm,  forest-clad 
land.  The  males  were  j^rovided  with  great  canine  teeth, 
which  served  them  as  formidable  weapons. 

At  a  much  earlier  period  the  uterus  was  double ;  the 
excreta  were  voided  through  a  cloaca ;  and  the  eye  was 
protected  by  a  third  eyelid  or  nictitating  membrane.  At 
a  still  earlier  period  the  progenitors  of  man  must  have 
been  aquatic  in  their  habits  ;  for  morphology  plainly  tells 
us  that  our  lungs  consist  of  a  modified  swim-bladder,  which 


Chap.  VI.]  AFFINITIES  AND   GENEALOGY.  199 

once  served  as  a  float.  The  clefts  011  the  neck  in  the  embryo 
of  man  show  There  the  branchiae  once  existed.  At  about 
this  period  the  true  kidneys  were  replaced  by  the  corpora 
wolffiana.  The  heart  existed  as  a  simple  pulsating  vessel ; 
and  the  chorda  dorsalis  took  the  place  of  a  vertebral  col- 
umn. These  early  predecessors  of  man,  thus  seen  in  the 
dim  recesses  of  time,  must  have  been  as  lowly  organized 
as  the  lancelet  or  amphioxus,  or  even  still  more  lowly  or- 
ganized. 

There  is  one  other  point  deserving  a  fuller  notice.  It 
has  long:  been  known  that  in  the  vertebrate  kingdom  one 
sex  bears  rudiments  of  various  accessory  parts,  appertain- 
ing to  the  reproductive  system,  which,  properly  belong  to 
the  opposite  sex ;  and  it  has  now  been  ascertained  that  at 
a  very  early  embryonic  period  both  sexes  possess  true 
male  and  female  glands.  Hence  some  extremely  remote 
progenitor  of  the  wliole  vertebrate  kingdom  appears  to 
have  been  hermajihrodite  or  androgynous."  But  here  we 
encounter  a  singular  difliculty.  In  the  mammalian  class 
the  males  possess  in  their  vesiculce  prostratica?  rudiments 
of  a  uterus  with  the  adjacent  passage  ;  they  bear  also 
rudiments  of  mamma?,  and  some  male  marsupials  have 
rudiments  of  a  marsupial  sack.^*  Other  analogous  facts 
could  be  added.  Are  we,  then,  to  suppose  that  some  ex- 
tremely ancient  mammal  possessed  organs  pro^^er  to  both 
sexes,  that  is,  continued  androgynous  after  it  had  acquired 

-■'  This  is  the  conclusion  of  one  of  tlio  highest  authorities  in  com- 
parative anatomy,  namely,  Prof.  Gcgenbaur:  '  Grundziige  der  vergleich. 
Anat.'  18*70,  s.  876.  The  result  has  been  arrived  at  chiefly  from  the 
study  of  the  Amphibia ;  but  it  appears  from  the  researches  of  Waldeyer 
(as  quoted  in  Humphry's  '  Journal  of  Anat.  and  Phys.'  1869,  p.  161), 
that  the  sexual  organs  of  even  "  the  higher  vertebrata  are,  in  their  early 
condition,  hermaphrodite."  Similar  views  have  long  been  held  by  some 
authors,  though  until  recently  not  well  based. 

^*  The  male  Thylacinus  offerd  the  best  instance.  Ov.'cn,  '  Anatomy 
of  Vertebrates,'  vol.  iii.  p.  771. 


200  THE   DESCENT   OF   MAN.  [Part  I. 

the  chief  distinctions  of  its  proper  chxss,  and  therefore  after 
it  liad  diverged  from  the  lower  classes  of  the  vertebrate 
kingdom  ?  Tliis  seems  improbable  in  the  highest  degree ; 
for,  had  this  been  the  case,  we  might  have  expected  that 
some  few  members  of  the  two  lower  classes,  namely  fishes  " 
and  amphibians,  would  still  have  remained  androgynous. 
We  must,  on  the  contrary,  believe  that  when  the  five  ver- 
tebrate classes  diverged  from  their  common  progenitor  the 
sexes  had  already  become  separated.  To  account,  how- 
ever, for  male  mammals  possessing  rudiments  of  the  accesso- 
ry female  organs,  and  for  female  mammals  possessing  rudi- 
ments of  the  masculine  organs,  we  need  not  suppose  that 
their  early  progenitors  were  still  androgynous  after  they  had 
assumed  their  chief  mammalian  characters.  It  is  quite  possi- 
ble that,  as  the  one  sex  gi'adually  acquired  the  accessory  or- 
gans proper  to  it,  some  of  the  successive  steps  or  modili- 
cations  were  transmitted  to  the  opposite  sex.  When  we 
treat  of  sexual  selection,  we  shall  meet  with  innumerable 
instances  of  this  form  of  transmission — as  in  the  case  of 
the  spurs,  plumes,  and  brilliant  colors,  acquired  by  male 
birds  for  battle  or  ornament,  and  transferred  to  the  fe- 
males in  an  imperfect  or  rudimentary  condition. 

The  possession  by  male  mammals  of  functionally  im- 
perfect mammary  organs  is,  in  some  resjiects,  especially 
curious.  Tlie  Monotremata  ha^•c  the  proper  milk-secret- 
ing glands  with  orifices,  but  no  nipples  ;  and,  as  tiiese 
animals  stand  at  the  very  base  of  the  mammalian  series, 
it  is  probable  that  the  progenitors  of  the  class  possessed, 
in  like  manner,  the  milk-secreting  glands,  but  no  nipples. 
This  conclusion  is  supported  by  what  is  known  of  their 

*'  Serramis  is  well  known  often  to  be  in  an  licrmaphrodite  condition  ; 
Init  Dr.  Giinther  informs  me  that  he  is  convinced  that  this  is  not  its  nor- 
mal state.  Descent  from  an  ancient  androgynous  prototype  would,  how- 
ever, naturally  favor  and  explain,  to  a  certain  extent,  the  recurrence  of 
this  condition  in  these  fishes. 


Chap.  VI.]  AFFINITIES  AND   GENEALOGY.  oqi 

manner  of  development ;  for  Professor  Turner  informs  me, 
on  tlie  authority  of  Kolliker  and  Lauger,  that  in  the  em- 
bryo the  mammary  glands  can  be  distinctly  traced  before 
the  nipples  are  in  the  least  visible ;  and  it  should  be  borne 
in  mind  that  the  development  of  successive  parts  in  the 
individual  generally  seems  to  represent  and  accord  with 
the  development  of  successive  beings  in  the  same  line  of 
descent.  The  Marsupials  differ  from  the  Monotremata  by 
possessing  nipples ;  so  that  these  organs  were  probably  first 
acquired  by  the  Marsitpials  after  they  had  diverged  from, 
and  risen  above,  the  Monotremata,  and  were  then  trans- 
mitted to  the  placental  mammals.  No  one  will  suppose 
that  after  the  Marsujiials  had  approximately  acquired 
their  present  structure,  and  therefore  at  a  rather  late  pe- 
riod in  the  development  of  the  mammalian  series,  any  of 
its  members  still  remained  androgynous.  We  seem,  there- 
fore, compelled  to  recur  to  the  foregoing  view,  and  to  con- 
clude that  the  nipples  were  first  developed  in  the  females 
of  some  very  early  marsupial  form,  and  were  then,  in  ac- 
cordance with  a  common  law  of  inheritance,  transferred 
in  a  functionally  imperfect  condition  to  the  males. 

Nevertheless,  a  suspicion  has  sometimes  crossed  my 
mind  that  long  after  the  progenitors  of  the  whole  mam- 
malian class  had  ceased  to  be  androgynous,  both  sexes 
might  have  yielded  milk  and  thus  nourished  their  young ; 
and,  in  the  case  of  the  Marsupials,  that  both  sexes  might 
have  carried  their  young  in  marsupial  sacks.  This  will 
not  appear  utterly  incredible,  if  we  reflect  that  the  males 
of  syngnathous  fishes  receive  the  eggs  of  the  females  in 
their  abdominal  pouches,  hatch  them,  and  afterward,  as 
some  believe,  nourish  the   young ;  "*   that   certain   other 

-''  Mr.  LocliTvood  believes  (as  quoted  in  '  Quart.  Journal  of  Science,' 
April,  1868,  p.  269),  from  what  he  has  observed  of  the  development  of 
Hipp'ocampus,  that  the  vralls  of  the  abdominal  pouch  of  the  male  in  some 
way  afford   nourishment.     On  male   fishes   hatching   the   ova   in  their 


202  THE  DESCENT   OF  MAX.  [Part  L 

male  fislies  hatch  the  eggs  witliin  their  mouths  or  bran- 
chial cavities ;  that  certain  male  toads  take  the  chaplets 
of  eggs  from  the  females  and  wind  them  round  their  own 
thighs,  keeping  them  there  until  the  tad2:»oles  are  born ; 
that  certain  male  birds  undertake  the  whole  duty  of  incu- 
bation, and  that  male  pigeons,  as  well  as  the  females,  feed 
their  nestlings  with  a  secretion  from  their  crops.  But  the 
above  suspicion  first  occurred  to  me  from  the  mammary 
glands  in  male  mammals  being  developed  so  much  more 
perfectly  than  the  rudiments  of  those  other  accessory  re- 
productive parts,  which  are  found  in  the  one  sex  though 
proper  to  the  otlier.  The  mammary  glands  and  nipples, 
as  they  exist  in  male  mammals,  can  indeed  hardly  be 
called  rudimentary ;  they  are  sim])ly  not  fully  developed 
and  not  functionally  active.  They  are  sympathetically 
affected  under  the  influence  of  certain  diseases,  like  the 
same  oi'gans  in  the  female.  At  birth  they  often  secrete  a 
few  drops  of  milk ;  and  they  have  been  known  occasion- 
ally in  man  and  other  mammals  to  become  well  devel- 
oped, and  to  yield  a  fair  supply  of  milk.  iSTow  if  we  sup- 
pose that  during  a  former  prolonged  period  male  mam- 
mals aided  the  females  in  nursing  their  offspring,  and  that 
afterward  from  some  cause,  as  from  a  smaller  number  of 
young  being  produced,  the  males  ceased  giving  this  aid, 
disuse  of  the  organs  during  maturity  would  lead  to  their 
becoming  inactive ;  and  from  two  well-known  principles 
of  inheritance  this  state  of  inactivity  would  probably  be 
transmitted  to  the  males  at  the  corresponding  age  of  ma- 
turity. But  at  all  earlier  ages  these  organs  would  be  left 
unaffected,  so  that  they  would  be  equally  well  developed 
in  the  young  of  both  sexes. 

mouths,  see  a  very  iatcresthig  paper  by  Prof.  Wyman,  in  '  Proc.  Boston 
Soc.  of  Nat.  Hist.' Sept.  15,  1857;  also  Prof.  Turner,  in  'Journal  of 
Anat.  and  Phys.'  Nov.  1,  1800,  p.  78.  Dr.  Giintherhas  likewise  described 
similar  cases. 


Chap.  YL]  AFFINITIES   AND   GENEALOGY.  203 

Conclusion. — The  best  definition  of  advancement  or 
progress  in  tlie  organic  scale  ever  given,  is  that  by  Von 
Baer ;  and  this  rests  on  the  amoiint  of  differentiation  and 
specialization  of  the  several  parts  of  the  same  being,  when 
arrived,  as  I  should  be  inclined  to  add,  at  maturity.  Now 
as  organism^s  have  become  slowly  adapted  by  means  of 
natural  selection  for  diversified  lines  of  life,  their  parts 
will  have  become,  from  the  advantage  gained  by  the  di- 
vision of  physiological  labor,  more  and  more  differentiated 
and  s^^ecializcd  for  A^arious  functions.  The  same  part  ap- 
I^ears  often  to  have  been  modified  first  for  one  purpose, 
and  then  long  afterward  for  some  other  and  quite  distinct 
purpose ;  and  thus  all  the  parts  are  rendered  more  and 
more  complex.  But  each  organism  will  still  retain  the 
general  type  of  structure  of  the  progenitor  from  which  it 
was  aboriginally  derived.  In  accordance  with  this  vicAV 
it  seems,  if  we  turn  to  geological  evidence,  that  organiza- 
tion on  the  whole  has  advanced  throughout  the  Avorld  by 
slov/  and  interrupted  stej)S.  Jn  the  great  kingdom  of  the 
Vertebrata  it  has  culminated  in  man.  It  must  not,  how- 
ever, be  supposed  that  groups  of  organic  beings  arc  al- 
v/ays  supplanted  and  disappear  as  soon  as  they  have 
given  birth  to  other  and  more  perfect  groups.  The  latter, 
though  victorious  over  their  predecessors,  may  not  have 
become  better  adapted  for  all  places  in  the  economy  of 
Nature.  Some  old  forms  appear  to  have  survived  from  in- 
habiting protected  sites,  where  they  have  not  been  ex- 
posed to  very  severe  competition ;  and  these  often  aid  us 
in  constructing  our  genealogies,  by  giving  us  a  fair  idea 
of  former  and  lost  populations.  But  we  must  not  fall  into 
the  error  of  looking  at  the  existing  members  of  any  lowly- 
organized  group  as  perfect  repi'esentativcs  of  their  ancient 
predecessors. 

The  most  ancient  progenitors  in  the  kingdom  of  the 
Vertebrata,  at  Avhich  wc  are  able  to  obtain  an  obscure 


204  THE   DESCENT   OF   MAX.  [Paut  I. 

glance,  apparently  consisted  of  a  group  of  marine  ani- 
inals,°'  resembling  the  larvas  of  existing  Ascidians.  These 
animals  probably  gave  rise  to  a  group  of  fishes,  as  lowly 
organized  as  the  lancelet ;  and  from  these  the  Ganoids, 
and  other  fishes  like  the  Lcpidosiren,  must  have  been  de- 
veloped. From  such  fish  a  very  small  advance  would 
carry  xis  on  to  the  amphibians.  We  have  seen  that  birds 
and  reptiles  were  once  intimately  connected  together ;  and 
the  Monotremata  now,  in  a  slight  degree,  connect  mam- 
mals with  reptiles.  But  no  one  can  at  present  say  by 
v.diat  line  of  descent  the  three  higher  and  related  classes, 
namely,  mammals,  birds,  and  reptiles,  vrerc  derived  from 
either  of  the  two  lower  vertebrate  classes,  namely  am- 
phibians and  fishes.  In  the  class  of  mammals  the  steps 
are  not  difficult  to  conceive  which  led  from  the  ancient 
i\Ionotremata  to  the  ancient  ^Marsupials ;  and  from  these 
to  the  early  progenitors  of  the  placental  mammals.  Wg 
may  thus  ascend  to  the  Lemuridce ;  and  the  interval  is  not 
wide  from  these  to  the  Simiada?.  The  Simiadjc  then 
branched  ofii"  into  two  great  stems,  the  New  World  and 
Old  World  monkeys ;  and  from  tlie  latter,  at  a  remote 

-■'  All  vital  functions  tend  to  run  their  course  in  fixed  and  recurrent 
periods,  and  with  tidal  animals  the  periods  would  probably  be  lunar ;  for 
such  animals  must  have  been  left  dry  or  covered  deep  with  water — sup- 
plied with  copious  food  or  stinted — during  endless  generations,  at  regular 
lunar  intervals.  If,  then,  the  vertcbrata  are  descended  from  an  animal 
allied  to  the  existing  tidal  Ascidians,  the  mysterious  fact  that,  with  the 
higher  and  now  terrestrial  Yertebrata,  not  to  mention  other  classes,  many 
normal  and  abnormal  vital  processes  run  their  course  according  to  lunar 
periods,  is  rendered  intelligible.  A  recurrent  period,  if  approximately 
of  the  right  duration,  when  once  gained,  would  not,  as  tixv  as  wc  can 
judge,  be  liable  to  be  changed  ;  consequently  it  might  be  thus  transmitted 
during  almost  any  number  of  generations.  This  conclusion,  if  it  could 
be  proved  sound,  would  be  curious  ;  for  we  should  then  see  that  the  pe- 
riod of  gestation  in  each  mammal,  and  the  hatching  of  each  bird's  eggs, 
and  many  ether  vital  processes,  still  betrayed  the  primordial  birthplace 
of  these  animals. 


CoAP.  TL]  AFFINITIES   AND   GENEALOGT.  205 

period,  Man,  the  wondci*  and  glory  of  the  Universe,  pro- 
ceeded. 

Thus  we  have  given  to  man  a  pedigree  of  prodigious 
length,  "but  not,  it  may  be  said,  of  noble  quality.  The 
world,  it  has  often  been  remarked,  appears  as  if  it  had 
long  been  prej^aring  for  the  advent  of  man  ;  and  this,  in 
one  sense  is  strictly  true,  for  he  owes  his  birth  to  a  long 
line  of  progenitors.  If  any  single  link  in  this  chain  had 
never  existed,  man  would  not  have  been  exactly  what  he 
now  is.  Unless  we  wilfully  close  our  eyes,  we  may,  with 
our  present  knowledge,  approximately  recognize  our  par- 
entage ;  nor  need  we  feel  ashamed  of  it.  The  most  hum- 
ble organism  is  something  much  higher  than  the  inorganic 
dust  under  our  feet ;  and  no  one  with  an  unbiassed  mind 
can  study  any  living  c^-cature,  however  humble,  without 
being  struck  v>'ith  enthusiasm  at  its  marvellous  structure 
and  properties. 


206  THE   DESCENT   OF  MAN.  [Paht  I. 


CHAPTER  VII. 

ON    THE    RACES    OF    IIAX, 

The  Nature  aud  Value  of  Specific  Cliaractcrs. — Application  to  the  Eaccs 
of  Man. — Arguments  in  favor  of,  and  ojiposcd  to,  ranking  the  So- 
called  Eaces  of  Man  as  Distinct  Species. — Sub-species. — Monogenists 
and  Polygeniats. — Convergence  of  Character. — Numerous  Points  of 
Eesemblance  in  Body  and  Mind  between  the  most  Distinct  Eaces  of 
Man. — The  State  of  Man  when  lie  first  spread  over  the  Earth. — Each 
Eace  not  descended  from  a  Single  Pair. — The  Extinction  of  Eaces. — 
The  Formation  of  Eaces. — The  Effects  of  Crossing. — Slight  Influence 
of  the  Direct  Action  of  the  Conditions  of  Life. — Slight  or  no  Influence 
of  Natural  Selection. — Sexual  Selection. 

It  is  not  my  intention  here  to  describe  tlie  several  so- 
called  races  of  men ;  but  to  inquire  wbat  is  the  A-alue  of 
the  differences  between  them  mider  a  classificatory  point 
of  view,  and  bow  tbey  bave  originated.  In  determining 
wbetber  tvro  or  more  allied  forms  ougbt  to  be  ranked  as 
species  or  varieties,  naturalists  are  practically  guided  by 
the  follovring  considerations :  namely,  the  amount  of  dif- 
ference between  them,  and  wliether  such  differences  relate 
to  few  or  many  points  of  structui-e,  and  whether  they  arc 
of  physiological  importance  ;  but  more  especially  whether 
they  are  constant.  Constancy  of  character  is  what  is 
chiefly  valued  and  sought  for  by  naturalists.  Whenever 
it  can  be  shown,  or  rendered  probable,  that  the  forms  in 
question  have  remained  distinct  for  a  long  period,  this  be- 
comes an  argument  of  mucli  Aveight  in  favor  of  treating 
them  as  species.    Even  a  slight  degree  of  sterility  betvreen 


Chap.  YIL]  THE   RACES   OF  MAN.  207 

auy  tAvo  forms  vv'lien  first  crossed,  or  in  their  offspring,  is 
generally  considered  as  a  decisive  test  of  their  specific 
distinctness;  and  their  continued  persistence  without 
blending  within  the  same  area,  is  usually  accepted  as 
sufficient  evidence,  either  of  some  degree  of  mutual  steril- 
ity, or  in  the  case  of  animals  of  some  repugnance  to 
mutual  pairing. 

Independently  of  Mending  from  intercrossing,  the 
complete  absence,  in  a  well-investigated  region,  of  vai-ie- 
ties  linking  together  any  two  closely-allied  forms,  is 
probably  the  most  important  of  all  the  criterions  of  their 
specific  distinctness  ;  and  this  is  a  SDmewhat  different  con- 
sideration from  mere  constancy  of  character,  for  two 
forms  may  be  highly  variable  and  yet  not  yield  inter- 
mediate varieties.  Geographical  distribution  is  often  un- 
consciously and  sometimes  consciously  brought  into  play ; 
BO  that  forms  living  in  two  widely-separated  areas,  in 
which  most  of  the  other  inhabitants  are  specifically  dis- 
tinct, are  themselves  usually  looked  at  as  distinct ;  but  in 
truth  this  affords  no  aid  in  distinguishing  geographical 
races  from  so-called  good  or  true  species, 

Now  let  us  apply  these  generally-admitted  principles 
to  the  races  of  man,  viewing  him  in  the  same  spirit  as  a 
naturalist  would  any  other  animal.  In  regard  to  the 
amount  of  difierence  between  the  races,  we  must  make 
some  allowance  for  our  nice  powers  of  discrimination 
gained  by  the  long  habit  of  observing  ourselves.  In  India, 
as  Elphinstone  remarks,*  although  a  newly-arrived  Euro- 
pean cannot  at  first  distinguish  the  various  native  races, 
yet  they  soon  appear  to  him  extremely  dissimilar;  and 
the  Hindoo  cannot  at  first  perceive  any  difierence  be- 
tween the  several  European  nations.  Even  the  most  dis- 
tinct races  of  man,  with  the  exception  of  certain  negro 

1  'History  of  India,'  1841,  vol.  i.  p.  323.  Father  Papa  makes  exactly 
the  same  remark  with  respect  to  the  Chinese. 


208  THE   DESCENT   OF   MAX.  [Part  I. 

tribes,  are  niucli  more  like  eacli  other  in  form  tliau  -would 
at  first  be  supposed.  This  is  well  shown  by  the  French 
photograplis  in  the  Collection  Anthropologique  duMuseiun 
of  the  men  belonging  to  various  races,  the  greater  number 
of  which,  as  many  persons  to  whom  I  have  shown  them 
have  remarked,  might  pass  for  Europeans.  Nevertheless, 
these  men  if  seen  alive  would  undoubtedly  appear  very 
distinct,  so  that  we  are  clearly  much  influenced  in  our 
judgment  by  the  mere  color  of  the  skin  and  hair,  by 
slight  diflerences  in  the  features,  and  by  expression. 

There  is,  however,  no  doubt  that  the  various  races, 
when  carefully  compared  and  measured,  differ  much  from 
each  other — as  in  the  texture  of  the  hair,  tlie  relative  pro- 
portions of  all  parts  of  the  body,''  the  capacity  of  the 
lungs,  the  fonn  and  capacity  of  the  skull,  and  even  in 
the  convolutions  of  the  brain.'  But  it  would  be  an  endless 
task  to  specify  the  numerous  points  of  structural  differ- 
ence. The  races  differ  also  in  constitution,  in  acclimatiza- 
tion, and  in  liability  to  cei'tain  diseases.  Their  mental 
characteristics  are  likewise  very  distinct ;  chiefly  as  it 
would  appear  in  their  emotional,  but  i^artly  in  their  intel- 
lectual, faculties.  Every  one  who  has  had  the  opportunity 
of  comparison,  must  have  been  struck  with  the  contrast 
between  the  taciturn,  even  morose,  aborigines  of  South 
America  and  the  light-hearted,  talkative  negroes.  There 
is  a  nearly  similar  contrast  between  the  Malays  and  the 
Papuans,*  who  live  under  the  same  physical  conditions, 

'  A  vast  number  of  measurements  of  White?,  Blacks,  and  Indians,  are 
given  in  the  '  Investigations  in  the  Military  and  Anthropolog.  Statistics 
of  American  Soldiers,'  by  B.  A.  Gould,  18G9,  pp.  298-358  ;  on  the  ca- 
pacity of  the  lungs,  p.  471.  See  also  the  numerous  and  valuable  tables, 
by  Dr.  Weisbach,  from  the  observations  of  Dr.  Scherzer  and  Dr.  Schwarz, 
in  the  'Reise  der  Novara:  Anthropolog.  Theil,'  18G7. 

*  See,  for  instance,  Mr.  Marshall's  account  of  the  brain  of  a  Bush- 
woman,  in  'Phil.  Transact.'  18G4,  p.  519. 

<  Wallace,  'The  Malay  Archipelago,'  vol.  ii.  1869,  p.  178. 


Chap.  YIL]  THE   RACES   OF   MAN.  209 

and  are  separated  from  each  other  only  by  a  narrow  space 
of  sea. 

We  will  first  consider  the  arguments  which  may  be 
advanced  in  favor  of  classing  the  races  of  man  as  distinct 
species,  and  then  those  on  the  other  side.  If  a  naturalist, 
who  had  never  before  seen  such  beings,  were  to  compare 
a  Negro,  Hottentot,  Australian,  or  Mongolian,  he  would 
at  once  perceive  that  they  differed  in  a  multitude  of 
characters,  some  of  slight  and  some  of  considerable  im- 
portance. On  inquiry  he  would  find  that  they  were  adapted 
to  live  under  widely-different  climates,  and  that  they  dif- 
fered somewhat  in  bodily  constitution  and  mental  dispo- 
sition. If  he  were  then  told  tliat  hundreds  of  similar 
specimens  could  be  brought  from  the  same  countries,  he 
would  assuredly  declare  that  they  were  as  good  species  as 
many  to  which  he  had  been  in  the  habit  of  aifixing  specific 
names.  This  conclusion  would  be  greatly  strengthened  as 
soon  as  he  had  ascertained  that  these  forms  had  all  re- 
tained the  same  character  for  many  centuries ;  and  that 
negroes,  apparently  identical  with  existing  negroes,  had 
lived  at  least  4,000  years  ago."     He  would  also  hear  from 

5  With  respect  to  the  figures  of  the  famous  Egyptian  caves  of  Abou- 
Simbel,  M.  Pouchet  says  ('  The  Plurality  of  the  Human  Races,'  English 
translat.  18G4,  p.  50),  that  he  was  far  from  finding  recognizable  repre- 
sentations of  the  dozen  or  more  nations  which  some  authors  believe  that 
they  can  recognize.  Even  some  of  the  most  strongly-marked  races  can- 
not be  identified  with  that  degree  of  unanimity  which  might  have  been 
expected  from  what  has  been  written  on  the  subject.  Thus  Messrs.  Nott 
and  Gliddon  ('  Types  of  Mankind,'  p.  148)  state  that  Rameses  II.,  or  the 
Great,  has  features  superbly  European  ;  whereas  Knox,  another  firm  be- 
liever in  the  specific  distinction  of  the  races  of  man  ('  Races  of  Man,' 
1850,  p.  201 ),  speaking  of  young  Memnon  (the  same  person  with  Rameses 
XL,  as  I  am  informed  by  Mr.  Birch)  insists  in  the  strongest  manner  that 
he  is  identical  in  character  with  the  Jews  of  Antwerp.  Again,  while 
looking  in  the  British  Museum  with  two  competent  judges,  officers  of  the 
estabUshment,  at  the  statue  of  Amunoph  III.,  we  agreed  that  he  had  a 

10 


210  THE   DESCENT   OF   MAN.  [Paut  I. 

an  excellent  observer,  Dr.  Lund,"  that  the  human  skulls 
found  in  the  caves  of  Brazil,  entombed  with  many  extinct 
mammals,  belonged  to  the  same  type  as  that  now  prevail- 
ing throughout  the  American  Continent. 

Our  naturalist  would  then,  perhaps,  turn  to  geograph- 
ical distribution,  and  he  would  probably  declare  that 
forms  differing  not  only  in  appearance,  but  fitted  for  the 
hottest  and  dampest  or  driest  countries,  as  well  as  for  the 
Arctic  regions,  must  be  distinct  species.  He  might  appeal 
to  the  fact  that  no  one  species  in  the  group  next  to  man, 
namely,  the  Quadrumana,  can  resist  a  low  temperature  or 
any  considerable  change  of  climate ;  and  that  those  species 
which  come  nearest  to  man  have  never  been  reared  to 
maturity,  even  under  the  temperate  climate  of  Europe. 
He  would  be  deeply  impressed  with  the  fact,  first  noticed 
by  Agassiz,^  that  the  diiFerent  races  of  man  are  distributed 
over  the  woi'ld  in  the  same  zoological  provinces,  as  those 
inhabited  by  undoubtedly  distinct  species  and  genera  of 
mammals.  This  is  manifestly  the  case  with  the  Australian, 
Mongolian,  and  Negro  races  of  man ;  in  a  less  M'ell-marked 
manner  with  the  Hottentots  ;  but  plainly  with  the  Papuans 
and  IMalays,  who  are  sej^arated,  as  Mr.  "Wallace  has 
shown,  by  nearly  the  same  line  which  divides  the  great 
Malayan  and  Australian  zoological  provinces.  The  ab- 
origines of  America  range  throughout  the  continent ;  and 
this  at  first  appears  opposed  to  the  above  rule,  for  most 
of  the  productions  of  the  Southern  and  Northern  halves 
differ  widely ;  yet  some  few  living  forms,  as  the  opossum, 

strongly  negro  cast  of  features ;  but  Messrs.  Nott  and  Gliddon  (ibid.  p. 
146,  fig.  53)  describe  him  as  "a  hybrid,  but  not  of  negro  intermixture." 

«  As  quoted  by  Kott  and  Gliddon,  'Types  of  Mankind,'  1854,  p.  439. 
They  give  also  corroborative  evidence  ;  but  C.  Vogt  thinks  that  the  sub- 
ject requires  further  investigation. 

'  "  Diversity  of  Origin  of  the  Human  Races,"  in  the  '  Christian  Ex- 
aminer,' July,  1850. 


Chap.  VII.]  THE   RACES   OF   MAN,  211 

range  from  the  one  into  the  other,  as  did  formerly  some 
of  the  gigantic  Edentata.  The  Esquimaux,  like  other 
Arctic  animals,  extend  round  the  whole  polar  regions.  It 
should  be  observed  that  the  mammalian  forms  v/liich  in- 
habit the  several  zoological  j^rovinces,  do  not  differ  from 
each  other  in  the  same  degree-;  so  that  it  can  hardly  be 
considered  as  an  anomaly  that  the  Negro  differs  more, 
and  the  American  much  less,  from  the  other  races  of  man 
than  do  the  mammals  of  the  same  continents  from  those 
of  the  other  provinces.  Man,  it  may  be  added,  does  not 
'appear  to  have  aboriginally  inhabited  any  oceanic  island ; 
and  in  this  respect  he  resembles  the  other  members  of  his 
class. 

In  determining  whether  the  varieties  of  the  same  kind 
of  domestic  animal  should  be  ranked  as  specifically  dis- 
tinct, that  is,  whether  any  of  them  are  descended  from 
distinct  wild  species,  every  naturalist  would  lay  much 
stress  on  the  fact,  if  established,  of  their  external  parasites 
being  s  ecifically  distinct.  All  the  more  stress  would  be 
laid  on  .his  fact,  as  it  would  be  an  exceptional  one,  for  I 
am  informed  by  Mr.  Denny  that  the  most  different  kinds 
of  dogs,  fowls,  and  pigeons,  in  England,  are  infested  by 
the  same  species  of  Pediculi  or  lice.  Now  Mr.  A,  Murray 
has  carefully  examined  the  Pediculi  collected  in  different 
countries  from  the  different  races  of  man ;  *  and  he  finds 
that  they  differ,  not  only  in  color,  but  in  the  structure  of 
their  claws  and  limbs.  In  every  case  in  which  numerous 
specimens  were  obtained  the  differences  were  constant. 
The  surgeon  of  a  whaling-ship  in  the  Pacific  assured  me 
that  when  the  Pediculi,  with  which  some  Sandwich  Island- 
ers on  board  swarmed,  strayed  on  to  the  bodies  of  the 
English  sailors,  they  died  in  the  course  of  three  or  four 
days.  These  Pediculi  were  darker  colored  and  appeared 
different  from  those  proper  to  the  natives  of  Chiloe  in 

«  '  Transact.  R.  Soc.  of  Edinburgh,'  vol.  xxii.  18G1,  p.  567. 


212  THE   DESCENT   OF  MAN  [PvnTl. 

South  America,  of  which  he  gave  me  specimens.  These, 
again,  appeared  larger  and  much  softer  than  European  lice. 
Mr.  ]Murray  procured  four  kinds  from  Africa,  namel}^  from 
the  Negroes  of  the  Eastern  and  Western  coasts,  from  the 
Hottentots  and  CaftVes  ;  two  kinds  from  the  natives  of 
Australia ;  two  from  North,  and  two  from  South  America. 
In  these  latter  cases  it  may  be  presumed  tliat  the  Pediculi 
came  from  natives  inhabiting  different  districts.  With 
insects  slight  structural  difierences,  if  constant,  are  gen- 
erally esteemed  of  specific  value:  and  the  fact  of  the  races 
of  man  being  infested  by  parasites,  which  appear  to  be 
specifically  distinct,  might  fairly  be  urged  as  an  argument 
that  the  races  themselves  ought  to  be  classed  as  distinct 
species. 

Our  supposed  naturalist,  having  proceeded  thus  far  in 
his  investigation,  would  next  inquire  whether  the  races  of 
men,  when  crossed,  were  in  any  degree  sterile.  lie  might 
consult  the  work"  of  a  cautious  and  philosophical  ob- 
server, Prof.  Broca ;  and  in  this  he  would  find  good  evi- 
dence that  some  races  were  quite  fertile  together;  but 
evidence  of  an  opposite  nature  in  regard  to  other  I'aces. 
Thus  it  has  been  asserted  that  the  native  women  of  Aus- 
tralia and  Tasmania  rarely  produce  children  to  European 
men ;  the  evidence,  however,  on  this  head  has  now  been 
shown  to  be  almost  valueless.  The  half-castes  are  killed 
by  the  pure  blacks ;  and  an  account  has  lately  been  pub- 
lished of  eleven  half-caste  youths  murdered  and  burnt  at 
the  same  time,  whose  remains  were  found  by  the  police." 

'  '  On  the  Phenomena  of  Ilybridity  in  the  Genus  Homo,'  Eng.  trans- 
lation, 18G4. 

'"  See  the  interesting  letter  by  Mr.  T.  A.  Murray,  in  the  'Anthropo- 
log.  Review,'  April,  1868,  p.  liii.  In  this  letter  Count  Strzeleeki's  state- 
ment, that  Australian  women  who  have  borne  children  to  a  white  man 
are  afterward  sterile  with  their  own  race,  is  disproved.  M.  A.  de  Qua- 
trcfages  has  also  collected  ('Revue  des  Cours  Scientifiques,'  March,  1869, 


Chap.  VII.]  THE   RACES   OF  MAN.  213 

Again,  it  has  often  been  said  that  when  mulattoes  inter- 
marry they  produce  few  children ;  on  the  other  hand,  Dr. 
Bachman  of  Charleston "  positively  asserts  that  he  has 
known  mulatto  families  which  have  intermarried  for  sev- 
eral generations,  and  have  continued  on  an  average  as 
fertile  as  either  pure  whites  or  pure  blacks.  Inquiries 
formerly  made  by  Sir  C.  Lyell  on  this  subject  led  him,  as 
he  informs  me,  to  the  same  conclusion.  In  the  United 
States  the  census  for  the  year  1854  iitcluded,  according  to 
Dr.  Bachman,  405,751  mulattoes;  and  this  number,  con- 
sidering all  the  cix'ciimstances  of  the  case,  seems  small ; 
but  it  may  partly  be  accounted  for  by  the  degraded  and 
anomalous  position  of  the  class,  and  by  the  profligacy  of 
the  women.  A  certain  amount  of  absorption  of  mulattoes 
into  negroes  must  always  be  in  progress ;  and  this  would 
lead  to  an  appai*ent  diminution  of  the  former.  The  in- 
ferior vitality  of  mulattoes  is  spoken  of  in  a  trustworthy 
work  '^  as  a  well-known  i^henomenon ;  but  this  is  a  dif- 
ferent consideration  from  their  lessened  fertility ;  and  can 
hardly  be  advanced  as  a  proof  of  the  specific  distinctness 
of  the  parent  races.  No  doubt  both  animal  and  vegetable 
hybrids,  when  produced  from  extremely  distinct  species, 
are  liable  to  premature  death;  but  the  parents  of  mulat- 
toes cannot  be  put  under  the  category  of  extremely  dis- 
tinct species.  The  common  Mule,  so  notorious  for  long 
life  and  vigor,  and  yet  so  sterile,  shows  how  little  necessary 
connection  there  is  in  hybrids  between  lessened  fertility 
and^vitality :  other  analogous  cases  could  be  added. 

Even  if  it  should  hereafter  be  proved  that  all  the  races 

p.  239)  much  evidence  that  Austrahans  and  Europeans  are  not  sterile 
when  crossed. 

'^  '  An  Examination  of  Prof.  Agassiz's  Sketch  of  the  Nat.  Provinces 
of  the  Animal  World,'  Charleston,  1855,  p.  44. 

'2  '  Military  and  Anthropolog.  Statistics  of  American  Soldiers,'  by 
B.  A.  Gould,  18G9,  p.  319. 


214  THE  DESCENT   OF   MAX.  [Part  I. 

of  men  were  perfectly  fertile  together,  he  who  was  inclined 
from  other  reasons  to  rank  them  as  distinct  species,  might 
with  justice  argue  that  fertility  and  sterility  are  not  safe 
criterions  of  specific  distinctness.  We  know  that  these 
qualities  are  easily  aftected  by  changed  conditions  of  life 
or  by  close  inter-breeding,  and  that  they  are  governed  by 
highly  comjjlex  laws,  for  instance  that  of  the  unequal  fer- 
tility of  reciprocal  crosses  between  the  same  two  species. 
With  forms  which  niust  be  ranked  as  undoubted  species, 
a  perfect  series  exists  from  those  which  are  absolutely 
sterile  when  crossed,  to  those  which  are  almost  or  quite 
fertile.  The  degrees  of  sterility  do  not  coincide  strictly 
Avith  the  degrees  of  difference  in  external  structure  or  hab- 
its of  life.  Man  in  many  respects  may  be  compared  with 
those  animals  which  have  long  been  domesticated,  and  a 
large  body  of  evidence  can  be  advanced  in  favor  of  the 
Pallasian  doctrine, "  that  domestication  tends  to  eliminate 

'3  '  The  Variation  of  Aoimals  and  Plants  under  Domestication,'  vol.  ii. 
p.  109.  I  may  here  remind  the  reader  that  the  sterility  of  species  when 
crossed  is  not  a  specially-acquired  quality ;  but,  like  the  incapacity  of 
certain  trees  to  be  grafted  together,  is  incidental  on  other  acquired  dif- 
ferences. The  nature  of  these  differences  is  unknown,  but  they  relate 
more  especially  to  the  reproductive  system,  and  much  less  to  external 
structure  or  to  ordinary  differences  in  constitution.  One  important  cle- 
ment in  the  sterility  of  crossed  species  apparently  lies  in  one  or  both 
having  been  loug  habituated  to  fixed  conditioris ;  for  we  know  that 
changed  conditions  have  a  ppccial  influence  on  the  reproductive  system, 
and  we  have  good  reason  to  believe  (as  before  remarked)  that  the  fluctu- 
ating conditions  of  domestication  tend  to  eliminate  that  stei-ility  which  is 
so  general  with  species  in  a  natural  state  when  crossed.  It  has  elsewhere 
been  shown  by  me  (ibid.  vol.  ii.  p.  185,  and  '  Origin  of  Species.'  5th  edit, 
p.  317)  that  the  sterility  of  crossed  species  has  not  been  acquired  through 
natural  selection :  we  can  see  that  when  two  forms  have  already  been 
rendered  very  sterile,  it  is  scarcely  possible  that  their  sterility  should  be 
augmented  by  the  preservation  or  survival  of  the  more  and  more  sterile 
individuals ;  for  as  the  sterility  increases  fewer  and  fewer  oflspring  will 
be  produced  from  whicli  to  breed,  and  at  last  only  single  individuals  will 
be    produced,    at    the  rarest  intervals      But    there    is    even    a    higher 


CnAP.  TIL]  TnE   RACES  OF   MAN.  215 

the  sterility  which  is  so  general  a  result  of  the  crossing  of 
species  in  a  state  of  nature.  From  these  several  consid- 
erations, it  may  be  justly  urged  that  the  perfect  fertility 
of  the  intercrossed  races  of  man,  if  establislied,  would 
not  absolutely  preclude  us  from  ranking  them  as  distinct 
species. 

Independently  of  fertility,  the  character  of  the  offspring 
from  a  cross  has  sometimes  been  thought  to  afford  evidence 
whether  the  parent-forms  ought  to  be  ranked  as  species  or 
varieties  ;  but  after  carefully  studying  the  evidence,  I  have 
come  to  the  conclusion  that  no  general  rules  of  this  kind 
can  be  trusted.  Thus  with  mankind  the  offspring  of  dis- 
tinct races  resemble  in  all  respects  the  offsjjring  of  true 
species  and  of  varieties.  This  is  shown,  for  instance,  by 
the  manner  in  which  the  characters  of  both  parents  are 
blended,  and  by  one  form  absorbing  another  through  re- 
peated crosses.  In  this  latter  case  the  progeny  both  of 
crossed  species  and  varieties  retain  for  a  long  period  a  ten- 
dency to  revert  to  tiieir  ancestors,  especially  to  that  one 
which  is  prepotent  in  transmission.  When  any  character 
has  suddenly  appeared  in  a  race  or  species  as  the  result 
of  a  single  act  of  variation,  as  is  general  with  monstrosi- 
ties," and  this  race  is  crossed  Avith  another  not  thus  char- 
acterized, the  characters  in  question  do  not  commonly  ap- 

grade  of  sterility  than  this.  Both  Gartner  and  Koh-euter  have  proved 
that  in  genera  of  plants  including  numerous  species,  a  series  can  be 
formed  from  species  which  v.'hen  crossed  yield  fewer  and  fewer  seeds, 
to  species  which  never  produce  a  single  seed,  but  yet  are  affected  by  the 
pollen  of  the  other  species,  for  the  germen  swells.  It  is  here  manifestly 
impossible  to  select  the  more  sterile  individuals,  which  have  already 
ceased  to  yield  seeds ;  so  that  the  acme  of  sterility,  when  the  germen 
alone  is  affected,  cannot  be  gained  through  selection.  This  acme,  and 
no  doubt  the  other  grades  of  sterility,  are  the  incidental  results  of  certain 
unknown  differences  in  the  constitution  of  the  reproductive  system  of  the 
species  which  are  crossed. 

'*  'The  Variation  of  Animals,'  etc.,  vol.  ii.  p.  92. 


21G  THE   DESCENT   OF   MAX.  [Part  I. 

pear  in  a  blended  condition  in  the  young,  but  are  trans- 
mitted to  them  either  perfectly  developed  or  not  at  all. 
As  Avith  the  crossed  races  of  man  cases  of  tliis  kind  rarely 
or  never  occur,  this  may  be  used  as  an  argument  against 
the  view  suggested  by  some  ethnologists,  namely,  that 
certain  characters,  for  instance  the  blackness  of  the  negro, 
first  appeared  as  a  sudden  variation  or  sport.  Had  this 
occurred,  it  is  probable  that  mulattoes  would  often  have 
been  born  either  completely  black  or  completely  white. 

AVe  have  now  seen  that  a  naturalist  might  feel  himself 
fully  justified  in  ranking  the  i-aces  of  man  as  distinct  spe- 
cies ;  for  he  has  found  that  they  are  distinguished  by  many 
difierences  in  structure  and  constitution,  some  being  of  im- 
portance. These  differences  have,  also,  remained  nearly 
constant  for  very  long  periods  of  time.  He  will  have  been 
in  some  degree  influenced  by  the  enormous  range  of  man, 
-which  is  a  great  anomaly  in  the  class  of  mammals,  if  man- 
kind be  viewed  as  a  single  species.  He  will  have  been 
struck  with  the  distribution  of  the  several  so-called  races, 
in  accordance  Avith  that  of  other  undoubtedly  distinct 
species  of  mammals.  Finally,  he  might  urge  that  the  mu- 
tual fertility  of  all  the  races  has  not  yet  been  fully  proved ; 
and  even  if  proved  would  not  be  an  absolute  proof  of  their 
specific  identity. 

On  the  other  side  of  the  question,  if  our  supposed  natu- 
ralist were  to  inquire  whether  the  forms  of  man  kept  dis- 
tinct like  ordinary  species,  when  mingled  together  in  large 
numbers  in  the  same  country,  he  woidd  immediately  dis- 
cover that  this  was  by  no  means  the  case.  In  Brazil  he 
would  behold  an  immense  mongrel  j^opulation  of  Negroes 
and  Portuguese  ;  in  Chiloe  and  other  parts  of  South  Amer- 
ica he  would  behold  the  Avhole  population  consisting  of 
Indians  and  Spaniards  blended  in  various  degrees.'*     In 

'5  M.  de  Quatrefages  has  given  (' Authropolog.   Kcvicw,' Jan.  18C0, 


Chap.  YII.]  THE   RACES   OF  MAN.  217 

many  parts  of  the  same  continent  he  would  meet  with 
the  most  complex  crosses  between  Negroes,  Indians,  and 
Europeans ;  and  such  triple  crosses  afford  the  severest 
test,  judging  from  the  vegetable  kingdom,  of  the  mutual 
fertility  of  the  parent-forms.  In  one  island  of  the  Pacific 
he  would  find  a  small  population  of  mingled  Polynesian 
and  English  blood ;  and  in  tlie  Viti  Archipelago  a  popu- 
lation of  Polynesians  and  Negritos  crossed  in  all  degrees. 
Many  analogous  cases  could  be  added,  for  instance,  in 
South  Africa.  Hence  the  races  of  man  are  not  sufiicient- 
ly  distinct  to  coexist  without  fusion ;  and  this  it  is  which, 
in  all  ordinary  cases,  affords  the  usual  test  of  specific  dis- 
tinctness. 

Our  naturalist  would  likcAvise  be  much  disturbed  as 
soon  as  he  perceived  that  the  distinctive  characters  of 
every  race  of  man  were  highly  variable.  This  strikes 
every  one  when  he  first  beholds  the  negro-slaves  in  Brazil, 
who  have  been  imported  from  all  parts  of  Africa.  The 
same  remark  holds  good  with  the  Polynesians,  and  with 
many  other  races.  It  may  be  doubted  whether  any  char- 
acter can  be  named  Avhich  is  distinctive  of  a  race  and  is 
constant.  Savages,  even  within  the  limits  of  the  same 
tribe,  are  not  nearly  so  uniform  in  character  as  has  often 
been  said.  Hottentot  women  offer  certain  peculiarities, 
more  strongly  marked  than  those  occiirring  in  any  other 
race,  but  these  are  known  not  to  be  of  constant  occurrence. 
In  the  several  American  tribes,  color  and  hau*iness  differ 
considerably ;  as  does  color  to  a  certain  degree,  and  the 
shape  of  the  features  greatly,  in  the  Negroes  of  Africa. 
The  shape  of  the  skull  varies  much  in  some  races ; '°  and 

p.  22)  an  interesting  account  of  the  success  and  energy  of  the  Paulistas 
in  Brazil,  who  are  a  much  crossed  race  of  Portuguese  and  Indian?,  with 
a  mixture  of  the  blood  of  other  races. 

"  For  instance  with  the  aborigines  of  America  and  Australia.     Prof. 
Huxley  says  ('  Transact.  Intemat.  Congress  of  Prehist.  Arch.'  1868,  p. 


218  THE   DESCENT   OF   MAX.  [Part  I. 

eo  it  is  with  every  other  character.  Xow  all  naturalists 
have  learned,  by  dearly-bought  experience,  how  rash  it 
is  to  attempt  to  define  species  by  the  aid  of  inconstant 
characters. 

But  the  most  weighty  of  all  the  arguments  against 
treating  the  races  of  man  as  distinct  species,  is  that  they 
graduate  into  each  other,  independently  in  many  cases,  as 
far  as  we  can  judge,  of  their  having  intercrossed.  Man 
has  been  studied  more  carefully  than  any  other  organic 
being,  and  yet  there  is  the  greatest  possible  diversity 
among  capable  judges  whether  he  should  be  classed  as  a 
single  species  or  race,  or  as  two  (Virey),  as  thi'ce  (Jacqui- 
not),  as  four  (Kant),  five  (Blumenbach),  six  (Buffon),  seven 
(Hunter),  eight  (Agassiz),  eleven  (Pickering),  fifteen  (Bory 
St,  Vincent),  sixteen  (Desraoulins),  twenty-two  (Morton), 
sixty  (Crawfurd),  or  as  sixty-three,  according  to  Burke," 
This  diversity  of  judgment  does  not  prove  that  the  races 
ought  not  to  be  ranked  as  species,  but  it  shows  that  they 
graduate  into  each  other,  and  that  it  is  hardly  possible  to 
discover  clear  distinctive  characters  between  them. 

Every  naturalist  who  has  had  the  misfortune  to  i;nder- 
take  the  description  of  a  group  of  highly-varying  organ- 
isms, has  encountered  cases  (I  speak  after  experience) 
precisely  like  that  of  man;  and  if  of  a  cautious  disposi- 
tion, he  will  end  by  uniting  all  the  forms  which  graduate 
into  each  other  as  a  single  species  ;  for  he  will  say  to  him- 
self that  he  has  no  right  to  give  names  to  objects  which 
he  cannot  define.  Cases  of  this  kind  occur  in  the  Order 
which  includes  man,  namely,  in  certain  genera  of  monkeys ; 

105)  fhat  the  skulls  of  many  South  Germans  and  Swiss  are  "as  short  and 
as  broad  as  those  of  the  Tartars,"  ete. 

"  Sec  a  good  discussion  on  this  subject  in  Waitz,  'Introduct.  to  An- 
thropology,' Eng.  translat.  1863,  pp.  198-208,  227.  I  have  taken  some 
of  the  above  statements  from  H.  Tuttle's  '  Origin  and  Antiquity  of  Physical 
Man,'  Boston,  1866,  p.  .35. 


Chap.  VII.]  THE   RACES   OF   MAN.  219 

while  in  other  genera,  as  in  Cercopithecus,  most  of  the 
species  can  be  determined  with  certainty.  In  the  Ameri- 
can genus  Cebus,  the  various  forms  are  ranked  by  some 
naturalists  as  species,  by  otiiers  as  mere  geographical 
races.  IvTow,  if  numerous  specimens  of  Cebus  were  col- 
lected from  all  parts  of  South  America,  and  those  forms 
which  at  present  appear  to  be  specifically  distinct,  were 
found  to  graduate  into  each  other  by  close  steps,  they 
would  be  ranked  by  most  naturalists  as  mere  varieties  or 
races  ;  and  thus  the  greater  number  of  naturalists  have 
acted  with  resj^ect  to  the  races  of  m-an.  Nevertheless  it 
must  be  confessed  that  there  are  forms,  at  least  in  the 
vegetable  kingdom,"  which  we  cannot  avoid  naming  as 
species,  but  which  are  connected  together,  independently 
of  intercrossing,  by  numberless  gradations. 

Some  naturalists  have  lately  employed  the  term  "  sub- 
species "  to  designate  forms  which  possess  many  of  the 
characteristics  of  true  species,  but  which  hardly  deserve 
so  high  a  rank.  Now,  if  we  reflect  on  the  weighty  argu- 
ments, above  given,  for  raising  the  races  of  man  to  the 
dignity  of  species,  and  the  insuperable  difficulties  on  the 
other  side  in  defining  them,  the  term  "  sub-s^iecies  "  might 
here  be  used  with  much  propriety.  But  from  long  habit 
the  term  "  race '"  will  perhaps  always  be  employed.  The 
choice  of  terms  is  only  so  far  important  as  it  is  highly  de- 
sirable to  use,  as  far  as  that  may  be  possible,  the  same 
terms  for  the  same  degrees  of  difference.  Unfortunately, 
this  is  rarely  possible;  for  within  the  same  family  the 
larger  genera  generally  include  closely-allied  forms,  which 
can  be  distinguished  only  with  much  difficulty,  while  the 
smaller  genera  include  forms  that  are  perfectly  distinct ; 

'*  Prof.  Nageli  has  carefully  described  several  striking  cases  in  his 
'Botanische  Mittheilungcn,'  B.  ii.  1866,  s.  294-369.  Prof.  Asa  Gray  ha3 
made  analogous  remarks  on  some  intermediate  forms  in  the  Compositaa 
of  North  America. 


220  THE   DESCENT   OF   MAX  [Part  I, 

yet  all  must  equally  be  ranked  as  species.  So  again  the 
species  within  the  same  large  genus  by  no  means  resemble 
each  other  to  the  same  degree :  on  the  contrary,  in  most 
cases  some  of  them  can  be  arranged  in  little  groups  round 
other  species,  like  satellites  round  planets." 

The  question  -whether  mankind  consists  of  one  or  sev- 
eral species  has  of  late  years  been  much  agitated  by  an- 
thropologists, who  are  divided  into  two  schools  of  mono- 
genists  and  polygenists.  Those  who  do  not  admit  the 
13i"inciple  of  evolution,  must  look  at  species  either  as  sep- 
arate creations  or  as  in  some  manner  distinct  entities ; 
and  they  must  decide  what  forms  to  rank  as  species  by 
the  analogy  of  other  organic  beings  which  are  commonly 
thus  received.  But  it  is  a  hopeless  endeavor  to  decide 
this  point  on  sound  grounds,  until  some  definition  of  the 
term  "  species  "  is  generally  accepted  ;  and  the  definition 
must  not  include  an  element  which  cannot  possibly  be  as- 
certained, such  as  an  act  of  creation.  We  might  as  well 
attempt  without  any  definition  to  decide  whether  a  cer- 
tain number  of  houses  should  be  called  a  village,  or  town, 
or  city.  We  have  a  practical  illustration  of  the  difiiculty 
in  the  never-ending  doubts  whether  many  closely-allied 
mammals,  birds,  insects,  and  plants,  which  represent  each 
other  in  North  America  and  Europe,  should  be  ranked 
species  or  geographical  races ;  and  so  it  is  with  the  pro- 
ductions of  many  islands  situated  at  some  little  distance 
from  the  nearest  continent. 

Those  naturalists,  on  the  other  hand,  who  admit  the 
principle  of  evolution,  and  this  is  now  admitted  by  the 
greater  number  of  rising  men,  will  feel  no  doubt  that  all 
the  races  of  man  are  descended  from  a  single  primitive 
stock ;  whether  or  not  they  think  fit  to  designate  them  as 
distinct  si:)ccics,  for  the  sake  of  expressing  their  amount 

19  '  Origin  of  Species,'  6tb  edit.  p.  G8. 


Chap.  VII.]  THE   RACES   OF  MAN.  221 

of  diiTerence.^"  With  our  domestic  animals  the  question 
whether  the  various  races  have  arisen  from  one  or  more 
species  is  different.  Although  all  such  races,  as  well  as 
all  the  natural  species  within  the  same  genus,  have  un- 
doubtedly sj^rung  from  the  same  primitive  stock,  yet  it  is 
a  fit  subject  for  discussion,  whether,  for  instance,  all  the 
domestic  races  of  the  dog  have  acquired  their  present 
differences  since  some  one  species  was  first  domesticated 
and  bred  by  man ;  or  whether  they  owe  some  of  their 
characters  to  inheritance  from  distinct  species,  which  had 
already  been  modified  in  a  state  of  nature.  With  man- 
kind no  such  question  can  arise,  for  he  cannot  be  said  to 
have  been  domesticated  at  any  particular  period. 

When  the  races  of  man  diverged  at  an  extremely  re- 
mote epoch  from  their  common  progenitor,  they  will  have 
differed  but  little  from  each  other,  and  been  few  in  num- 
ber ;  consequently  they  will  then,  as  far  as  their  distin- 
guishing characters  are  concerned,  have  had  less  claim  to 
rank  as  distinct  species,  than  the  existing  so-called  races. 
Nevertheless  such  early  races  would  perhaps  have  been 
ranked  by  some  naturalists  as  distinct  species,  so  arbitrary 
is  the  term,  if  their  differences,  although  extremely  slight, 
had  been  more  constant  than  at  present,  and  had  not 
graduated  into  each  other. 

It  is,  however,  possible,  though  far  from  probable, 
that  the  early  progenitors  of  man  might  at  first  have  di- 
verged much  in  character,  until  they  became  more  unlike 
each  other  than  are  any  existing  races  ;  but  that  subse- 
quently, as  suggested  by  Vogt,*"  they  converged  in  char- 
acter. When  man  selects  for  the  same  object  the  off- 
spring of  two  distinct  species,  he  sometimes  induces,  as 
far  as   general   appearance  is  concerned,  a  considerable 

20  See  Prof.  Huxley  to  this  effect  in  the  'Fortnightly  Review,'  1863, 
p.  275. 

2'  '  Lectures  on  Man,'  Eng.  translat.  1864,  p.  468. 


222  THE   DESCENT   OF  MAN.  [Part  I. 

amount  of  convergence.  This  is  the  case,  as  shown  by 
Yon  Nathusius,"  -with  the  improved  breeds  of  pigs,  which 
are  descended  from  two  distinct  species ;  and  in  a  less 
well-marked  manner  Avith  the  improved  breeds  of  cattle. 
A  great  anatomist,  Gratiolct,  maintains  tliat  the  anthro- 
pomorphous apes  do  not  form  a  natural  sub-group ;  but 
that  tlie  orang  is  a  highly-developed  gibbon  or  semno- 
pithecus  ;  the  chimpanzee  a  highly-developed  macacus ;  and 
the  gorilla  a  highly-developed  mandrilL  If  this  conclu- 
sion, which  rests  almost  exclusively  on  brain-characters, 
be  admitted,  we  should  have  a  case  of  convergence  at 
least  in  external  characters,  for  the  anthropomorj^hous 
apes  are  certainly  more  like  each  other  in  many  points 
than  they  are  to  other  apes.  All  analogical  resemblances, 
as  of  a  whale  to  a  fish,  may  indeed  be  said  to  be  cases  of 
convergence  ;  but  this  term  has  never  been  applied  to 
superficial  and  adaptive  resemblances.  It  would  be  ex- 
tremely rash  in  most  cases  to  attribute  to  convergence 
close  similarity  in  many  points  of  structure  in  bemgs 
Avliicli  had  once  been  widely  difierent.  The  form  of  a 
crystal  is  determined  solely  by  the  molecular  forces,  and 
it  is  not  surprising  that  dissimilar  substances  should  some- 
times assume  the  same  form ;  but  with  organic  beings  we 
should  bear  in  mind  that  the  form  of  each  depends  on  an 
infinitude  of  complex  relations,  namely,  on  the  variations 
which  have  arisen,  these  being  due  to  causes  far  too  intri- 
cate to  be  followed  out — on  the  nature  of  the  variations 
which  have  been  preserved,  and  this  depends  on  the  sur- 
rounding physical  conditions,  and  in  a  still  higher  degree 
on  the  suiTounding  organisms  with  wliich  each  has  come 
into  competition — and  lastly,  on  inheritance  (in  itself  a 
fluctuating  element)  from  innumerable  j^rogenitors,  all  of 

■^'Dic  Racen  des  Schwcincs,'  ISGO,  s.  46.  'Vorstudicn  fiir  Ge- 
schichtc,  etc.,  Schweineschiidcl,'  18frt,  s.  104.  'With  respect  to  cattle, 
see  M.  de  Quatrcfages,  'Unite  de  I'Especc  Ilumaine,'  1861,  p.  119. 


Chap.  VII.]  THE   RACES   OF   MAX.  223 

vvhich  have  had  their  forms  determined  through  equally- 
complex  relations.  It  appears  utterly  incredible  that  two 
organisms,  if  differing  in  a  marked  mannei',  should  ever 
afterward  converge  so  closely  as  to  lead  to  a  near  ap- 
proach to  identity  throughout  their  whole  organization. 
In  the  case  of  the  convergent  pigs  above  referred  to,  evi- 
dence of  their  descent  from  two  primitive  stocks  is  still 
plainly  retained,  according  to  Von  Nathusius,  in  certain 
bones  of  their  skulls.  If  the  races  of  man  were  descended, 
as  supposed  by  some  naturalists,  from  two  or  more  dis- 
tinct species,  which  had  differed  as  much,  or  nearly  as 
much,  from  each  other,  as  the  orang  differs  from  the  go- 
rilla, it  can  hardly  be  doubted  that  marked  differences  in 
the  structure  of  certain  bones  would  still  have  been  dis- 
coverable in  man  as  he  now  exists. 

Although  the  existing  races  of  man  differ  in  many  re- 
spects, as  in  color,  hair,  shape  of  skull,  proportions  of  the 
body,  etc.,  yet  if  their  whole  organization  be  taken  into 
consideration  they  are  found  to  resemble  each  other  closely 
in  a  multitude  of  points.  Many  of  these  points  are  of 
so  unimportant  or  of  so  singular  a  nature,  that  it  is  ex- 
tremely improbable  that  they  should  have  been  indepen- 
dently acquired  by  aboriginally  distinct  species  or  races. 
The  same  remark  holds  good  with  equal  or  greater  force 
with  respect  to  the  numerous  points  of  mental  similarity 
between  the  most  distinct  races  of  man.  The  American 
aborigines,  Kegroes,  and  Europeans,  differ  as  much  from 
each  other  in  mind  as  any  three  races  that  can  be  named ; 
yet  I  was  incessantly  struck,  while  living  with  the  Fue- 
gians  on  board  the  "  Beagle,"  with  the  many  little  traits 
of  character,  showing  how  similar  their  minds  were  to 
ours ;  and  so  it  was  with  a  full-blooded  negro  with  whom 
I  happened  once  to  be  intimate. 

He  who  will  carefully  read  Mr.  Tyler's  and  Sir  J.  Lub- 


224  THE   DESCENT   OF   MAN.  [Part  I. 

bock's  interesting  works''  can  hardly  fail  to  be  deeply  im- 
pressed with  the  close  similiarity  between  tlie  men  of  all 
races  in  tastes,  dispositions,  and  habits.  This  is  shown  by 
the  pleasure  Avhich  they  all  take  in  dancing,  rude  music, 
acting,  painting,  tattooing,  and  otherwise  decorating  them- 
selves— in  their  mutual  comprehension  of  gesture-language 
— and,  as  I  shall  be  able  to  show  in  a  future  essay,  by  the 
same  expression  in  their  features,  and  by  the  same  inar- 
ticulate cries,  when  they  are  excited  by  various  emotions. 
This  similarity,  or  rather  identity,  is  striking,  when  con- 
trasted with  the  different  expressions  which  may  be  ob- 
served in  distinct  species  of  monkeys.  There  is  good 
evidence  that  the  art  of  shooting  with  bows  and  arrows 
has  not  been  handed  down  from  any  common  progenitor 
of  mankind,  jct  the  stone  arrow-heads,  brought  from  the 
most  distant  parts  of  the  world  and  manufactured  at  the 
most  remote  periods,  are,  as  Nilsson  has  shown,"  almost 
identical ;  and  this  fact  can  only  be  accounted  for  by  the 
various  races  having  similar  inventive  or  mental  powers. 
The  same  observation  has  been  made  by  archaeologists "' 
with  respect  to  certain  widely-prevalent  ornaments,  such 
as  zigzags,  etc. ;  and  with  respect  to  various  simple  beliefs 
and  customs,  such  as  the  burying  of  the  dead  under 
megalithic  structures.  I  remember  observing  in  South 
America,"  that  there,  as  in  so  many  other  parts  of  the 
world,  man  has  generally  chosen  the  summits  of  lofty  hills, 
on  which  to  throw  up  piles  of  stones,  cither  for  the  sake  of 
recording  some  remarkable  event,  or  for  burying  his  dead. 

'^  Tylor's  'Early  History  of  Mankind,'  1865;  for  the  evidence  with 
respect  to  gesture-language,  see  p.  54.  Lubbock's  '  Prehistoric  Times,' 
2d  edit.  1869. 

^*  '  The  Primitive  Inhabitants  of  Scandinavia,'  Eng.  translat.  edited 
by  Sir  J.  Lubbock,  1868,  p.  lOt. 

^'^  Ilodder  M.  Westropp,  on  Cromlechs,  etc.,  '  Journal  of  Ethnological 
Soc'  as  given  in  'Scientific  Opinion,'  June  2,  1869,  p.  3. 

'*  '  Journal  of  Researches :  Voyage  of  the  "  Beagle,"  '  p.  40. 


Chap.  VII.]  THE   RACES   OF  MAN.  225 

Now,  when  naturalists  observe  a  close  agreement  in 
numerous  small  details  of  habits,  tastes,  and  dispositions, 
between  two  or  more  domestic  races,  or  between  nearly- 
allied  natural  forms,  they  use  this  fact  as  an  argument 
that  all  are  descended  from  a  common  progenitor  who 
was  thus  endowed ;  and  consequently  that  all  should  be 
classed  under  the  same  species.  The  same  argument  may 
be  applied  with  much  force  to  the  races  of  man. 

As  it  is  improbable  that  the  numerous  and  unimportant 
f)oints  of  resemblance  between  the  several  races  of  man 
in  bodily  structure  and  mental  faculties  (I  do  not  here  re- 
fer to  similar  customs)  should  all  have  been  independently 
acquired,  they  must  have  been  inherited  from  progenitors 
who  were  thus  characterized.  We  thus  gain  some  insight 
into  the  early  state  of  man,  before  he  had  spread  step  by 
stej)  over  the  face  of  the  earth.  The  spreading  of  man  to 
regions  widely-se^^arated  by  the  sea,  no  doubt,  preceded 
any  considerable  amount  of  divergence  of  character  in 
the  several  races ;  for  otherwise  we  should  sometimes 
meet  with  the  same  race  in  distinct  continents ;  and  this 
is  never  the  case.  Sir  J.  Lubbock,  after  comparing  the 
arts  now  practised  by  savages  in  all  parts  of  the  world, 
specifies  those  which  man  could  not  have  known,  when  he 
first  wandered  from  his  original  birthplace  ;  for  if  once 
learned  they  would  never  have  been  forgotten."'  He  thus 
shows  that  "  the  spear,  which  is  but  a  development  of  the 
knife-point,  and  the  club,  which  is  but  a  long  hammer,  ai-e 
the  only  things  left."  He  admits,  however,  that  the  art 
of  making  fire  probably  had  already  been  discovered,  for 
it  is  common  to  all  the  races  now  existing,  and  was  known 
to  the  ancient  cave-inhabitants  of  Europe.  Perhaps  the 
art  of  making  rude  canoes  or  rafts  was  likewise  known ; 
but  as  man  existed  at  a  remote  epoch,  when  the  land  in 
many  places  stood  at  a  very  different  level,  he  Avould  have 

"  'Prehistoric  Times,'  1869,  p.  574. 


226  THE  DESCENT  OF  MAN.  [Part  I. 

been  able,  without  the  aid  of  canoes,  to  have  spread  widely. 
Sir  J.  Lubbock  further  remarks  how  improbable  it  is  that 
our  earliest  ancestors  could  have  "  counted  as  high  as  ten, 
considering  that  so  many  races  now  in  existence  cannot 
get  beyond  four."  Nevertheless,  at  this  early  period,  the 
intellectual  and  social  faculties  of  man  could  hardly  have 
been  inferior  in  any  extreme  degree  to  those  now  pos- 
sessed by  the  lowest  savages ;  otherwise  primeval  man 
could  not  have  been  so  eminently  successful  in  the 
struggle  for  life,  as  jiroved  by  his  early  and  wide  dif- 
fusion. 

From  the  fundamental  differences  between  certain  lan- 
guages, some  philologists  have  inferred  that  when  man 
first  became  widely  diffused  he  was  not  a  speaking  ani- 
mal ;  but  it  may  be  suspected  that  languages,  far  less  per- 
fect than  any  now  spoken,  aided  by  gestures,  might  have 
been  used,  and  yet  have  left  no  traces  on  subsequent  and 
more  highly-developed  tongues.  Without  the  use  of  some 
language,  however  imperfect,  it  appears  doubtful  whether 
man's  intellect  could  have  risen  to  the  standard  implied 
by  his  dominant  position  at  an  early  period. 

Whether  primeval  man,  when  he  possessed  very  few 
arts  of  the  rudest  kind,  and  when  his  power  of  language 
was  extremely  imperfect,  would  have  deserved  to  be 
called  man,  must  depend  on  the  definition  which  we  em- 
ploy. In  a  series  of  forms  graduating  insensibly  from 
some  ape-like  ci-cature  to  man  as  he  now  exists,  it  would 
be  impossible  to  fix  on  any  definite  point  when  the  term 
*'  man  "  ought  to  be  used.  But  this  is  a  matter  of  very 
little  importance.  So  again  it  is  almost  a  matter  of  in- 
difference whether  the  so-called  races  of  man  are  thus 
designated,  or  are  ranked  as  species  or  sub-species ;  but 
the  latter  term  appears  the  most  appropriate.  Finally,  we 
may  conclude  that  when  the  principles  of  evolution  are 
generally  accepted,  as  they  surely  will  be  before  long,  the 


CnAP.  VII.]  THE   RACES   OF   MAN.  227 

dispute  between  the  monogeuists  and  the  polygenists  ■will 
die  a  silent  and  unohserved  death. 

One  other  question  ought  not  to  he  passed  over  with- 
out notice,  namely,  whether,  as  is  sometimes  assumed,  each 
sub-species  or  race  of  man  has  sprvmg  from  a  single  pair 
of  progenitors.  With  our  domestic  animals  a  new  race 
can  readily  be  formed  from  a  single  pair  possessing  some 
new  character,  or  even  from  a  single  individual  thus  char- 
acterized, by  carefully  matching  the  varying  offspring; 
but  most  of  our  races  have  been  formed,  not  intentionally 
from  a  selected  pair,  but  unconsciously  by  the  preservation 
of  many  individuals  which  have  varied,  however  slightly, 
in  some  useful  or  desired  manner.  If  in  one  country 
stronger  and  heavier  horses,  and  in  another  country  light- 
er and  fleeter  horses,  were  habitually  preferred,  we  may 
feel  svire  that  two  distinct  sub-breeds  would,  in  the  course 
of  time,  be  produced,  without  any  particular  pairs  or  indi- 
viduals having  been  separated  and  bred  from  in  either 
country.  Many  races  have  been  thus  formed,  and  their 
manner  of  formation  is  closely  analogous  with  that  of  natu- 
ral species.  We  know,  also,  that  the  horses  which  have 
been  brought  to  the  Falkland  Islands  have  become,  during 
successive  generations,  smaller  and  weaker,  while  those 
which  have  run  wild  on  the  Pampas  have  acquired  larger 
and  coarser  heads  ;  and  such  changes  are  manifestly  due, 
not  to  any  one  pair,  but  to  all  the  individuals  having  been 
subjected  to  the  same  conditions,  aided,  perhaps,  by  the 
principle  of  reversion.  The  new  sub-breeds  in  none  of 
these  cases  are  descended  from  any  single  pair,  but  from 
many  individuals  which  have  varied  in  different  degrees, 
but  in  the  same  general  manner;  and  we  may  conclude 
that  the  races  of  man  have  been  similarly  produced,  the 
modifications  being  either  the  direct  result  of  exposure  to 
different  conditions,  or  the  indirect  result  of  some  form  of 


228  THE   DESCENT   OF   MAN.  [Part  I. 

selection.     But  to  this  latter  subject  we  shall  presently  re- 
turn. 

On  the  Extinction  of  the  Races  of  Man. — The  jiartial 
and  complete  extinction  of  many  races  and  sub-races  of 
man  are  historically  known  events.  Humboldt  saw  in 
South  America  a  parrot  which  was  the  solo  living  creature 
that  could  speak  the  language  of  a  lost  tribe.  Ancient 
monuments  and  stone  implements  found  in  all  parts  of  the 
world,  of  which  no  tradition  is  preserved  by  the  present 
inhabitants,  indicate  much  extinction.  Some  small  and 
broken  tribes,  remnants  of  former  races,  still  survive  in 
isolated  and  generally  mountainous  districts.  In  Europe 
the  ancient  races  were  all,  according  to  Schaaffhauscn,°° 
"  lower  in  the  scale  than  the  rudest  living  savages  ; "  they 
must  therefore  have  difiered,  to  a  certain  extent,  from  any 
existing  race.  The  remains  described  by  Prof.  Broca" 
from  Les  Eyzies,  though  they  unfortunately  appear  to 
have  belonged  to  a  single  family,  indicate  a  race  with  a 
most  singular  combination  of  low  or  simious  and  high 
characteristics,  and  is  "  entirely  different  from  any  other 
race,  ancient  or  modern,  that  we  have  ever  heard  of."  It 
differed,  therefore,  from  the  quaternary  race  of  the  caverns 
of  Belgium. 

Unfavorable  physical  conditions  appear  to  have  had 
but  little  effect  in  the  extinction  of  races.'"  Man  has  long 
lived  in  the  extreme  regions  of  the  North,  with  no  wood 
wherewith  to  make  his  canoes  or  other  implements,  and 
with  blubber  alone  for  burning  and  giving  him  warmth, 
but  more  especially  for  melting  the  snow.     In  the  South- 

^^  Translation  in  'Anthropological  Review,'  Oct.  18G8,  p.  431. 

5'  'Transact.  Internal.  Congress  of  Prehistoric  Arch.'  1868,  pp.  172- 
175.  See  also  Broca  (translation)  in  'Anthropological  Review,'  Oct. 
1868,  p.  410. 

^^  Dr.  Gerland,  'Ucbcr  das  Ausstcrlicn  dcr  Xatiirvolker,'  1868,  s.  82. 


Chap.  VII.]  THE  RACES  OF  MAN.  229 

ern  extremity  of  America  the  Faegians  survive  without 
the  protection  of  clothes,  or  of  any  building  worthy  to  be 
called  a  hovel.  In  South  Africa  the  aborigines  wander 
over  the  most  arid  plains,  where  dangerous  beasts  abound. 
Man  can  withstand  the  deadly  influence  of  the  Terai  at 
the  foot  of  the  Himalaya,  and  the  pestilential  shores  of 
tropical  Africa. 

Extinction  follows  chiefly  from  the  competition  of  tribe 
with  tribe,  and  race  with  race.  Various  checks  are  always 
in  action,  as  specified  in  a  former  chapter,  which  serve  to 
keep  down  the  numbers  of  each  savage  tribe — such  as 
periodical  famines,  the  wandei-ing  of  the  parents  and  the 
consequent  deaths  of  infants,  prolonged  suckling,  the  steal- 
ing of  women,  wars,  accidents,  sickness,  licentiousness,  es- 
pecially infanticide,  and,  perhaps,  lessened  fertility  from 
less  nutritious  food,  and  many  hardships.  If  from  any 
cause  any  one  of  these  checks  is  lessened,  even  in  a  slight 
degree,  the  tribe  thus  favored  will  tend  to  increase ;  and 
when  one  of  two  adjoining  tribes  becomes  more  numerous 
and  powerful  than  the  other,  the  contest  is  soon  settled 
by  war,  slaughter,  cannibalism,  slavery,  and  absorption. 
Even  when  a  weaker  tribe  is  not  thus  abruptly  swept 
away,  if  it  once  begins  to  decrease,  it  generally  goes  on 
decreasing  until  it  is  extinct. '^ 

When  civilized  nations  come  into  contact  Avith  barba- 
rians the  struggle  is  short,  except  where  a  deadly  climate 
gives  its  aid  to  the  native  race.  Of  the  causes  which  lead 
to  the  victory  of  civilized  nations,  some  are  plain  and  some 
very  obscure.  We  can  see  that  the  cultivation  of  the  land 
will  be  fatal  in  many  ways  to  savages,  for  they  cannot,  or 
will  not,  change  their  habits.  New  diseases  and  vices  are 
highly  destructive ;  and  it  appears  that  in  every  nation  a 
new  disease  causes  much  death,  until  those  who  are  most 
susceptible  to  its  destructive  influence  are  gradually  weed- 
s' Gerland  (ibid.  s.  12)  gives  facts  in  support  of  this  statement. 


230  THE   DESCENT   OF   MAN.  [Part  I. 

ed  out ; "  and  so  it  may  be  with  the  evil  effects  from  spir- 
ituous liquors,  as  well  as  with  the  unconquerably  strong 
taste  for  them  shown  by  so  many  savages.  It  further  ap- 
pears, mysterious  as  is  the  fact,  that  the  first  meeting  of 
distinct  and  separated  people  generates  disease."  JNlr. 
Sproat,  who  in  Vancouver  Island  closely  attended  to  the 
subject  of  extinction,  believes  that  changed  habits  of  life, 
which  always  follow  from  the  advent  of  Europeans,  in- 
duces much  ill-health.  He  lays,  also,  great  stress  on  so  tri- 
fling a  cause  as  that  the  natives  become  "bewildered  and 
dull  by  the  new  life  around  them ;  they  lose  the  motives 
for  exertion,  and  get  no  ncAV  ones  in  their  place."  ^* 

The  grade  of  civilization  seems  a  most  important  ele- 
ment in  the  success  of  nations  which  come  in  competition. 
A  few  centuries  ago  Europe  feared  the  inroads  of  Eastern 
barbarians ;  now,  any  such  fear  would  be  ridiculous.  It 
is  a  more  curious  fact  that  savages  did  not  formerly  waste 
away,  as  Mr,  Bagehot  has  remarked,  before  the  classical 
nations,  as  they  nov/  do  before  modern  civilized  nations ; 
had  they  done  so,  the  old  moralists  would  have  mused 
over  the  event ;  but  there  is  no  lament  in  any  writer  of 
that  period  over  the  perishing  barbarians." 

Although  the  gradual  decrease  and  final  extinction  of 
the  races  of  man  is  an  obscure  pi'oblem,  we  can  see  that 
it  depends  on  many  causes,  differing  in  different  places 
and  at  different  times.  It  is  the  same  difficult  problem  as 
that  presented  by  the  extinction  of  one  of  the  higher  ani- 

*^  See  remarks  to  this  effect  in  Sir  11.  Holland's  '  Medical  Notes  and 
Reflections,'  1839,  p.  390. 

22  I  have  collected  ('  Journal  of  Researches,  Voyage  of  the  "  Beagle," ' 
p.  435)  a  good  many  cases  bearing  on  this  subject :  see  also  Gerlaud, 
ibid.  s.  8.  Poeppig  speaks  of  the  "  breath  of  civilization  as  poisonous 
to  savages." 

2*  Sproat,  'Scenes  and  Studies  of  Savage  Life,'  18GS,  p.  234. 

25  Bagehot,  "  Physics  and  Politics,"  '  Fortnightly  Review,'  April  1, 
18G8,  p.  455. 


Chap.  TIL]  THE   RACES   OF   MAN.  231 

mals — of  the  fossil  horse,  for  instance,  which  disappeared 
from  South  America,  soon  afterward  to  be  replaced,  with- 
in the  same  districts,  hj  countless  troops  of  the  Spanish 
horse.  The  New-Zealander  seems  conscious  of  this  paral- 
lelism, for  he  compares  his  future  fate  with  that  of  the 
native  rat  almost  exterminated  by  the  European  rat. 
The  difficulty,  though  great  to  our  imagination,  and  real- 
ly great  if  we  wish  to  ascertain  the  precise  causes,  ought 
not  to  be  so  to  our  reason,  as  long  as  we  keep  steadily  in 
mind  that  the  increase  of  each  species  and  each  race  is 
constantly  hindered  by  various  checks  ;  so  that  if  any  new 
check,  or  cause  of  destruction,  even  a  slight  one,  be  super- 
added, the  race  will  surely  decrease  in  number  ;  and  as  it 
has  everywhere  been  observed  that  savages  are  much  op- 
posed to  any  change  of  habits,  by  which  means  injurious 
checks  could  be  counterbalanced,  decreasing  numbers  will 
sooner  or  later  lead  to  extinction ;  the  end,  in  most  cases, 
being  promptly  determined  by  the  inroads  of  increasing 
and  conquering  tribes. 

On  the  Formation  of  the  JRaces  of  Man. — It  may  be 
premised  that  when  we  find  the  same  race,  though  broken 
up  into  distinct  tribes,  ranging  over  a  great  area,  as  over 
America,  we  may  attribute  their  general  resemblance  to 
descent  from  a  common  stock.  In  some  cases  tlie  cross- 
ing of  races  ali'eady  distinct  has  led  to  the  formation  of 
new  races.  The  singular  fact  that  Europeans  and  Hin- 
doos, who  belong  to  the  same  Aryan  stock  and  speak  a 
language  fundamentally  the  same,  differ  widely  in  ap- 
pearance, while  Europeans  differ  but  little  from  Jews,  who 
belong  to  the  Semitic  stock  and  speak  quite  another  lan- 
guage, has  been  accounted  for  by  Broca^"  through  the 
Aryan  branches  having  been  largely  crossed  during  their 

2^  "  On  Anthropology,"  translation, '  Anthropolog.  Review,'  Jan.  18G8, 
p.  38. 


232  THE   DESCENT   OF  MAX.  [Part  L 

wide  diffusion  by  various  iiifligenous  tribes.  When  two 
races  in  close  contact  cross,  the  first  result  is  a  heterogene- 
ous mixture :  thus  Mr,  Hunter,  in  describing  the  Santali 
or  hill-tribes  of  India,  says  that  hundreds  of  impercep- 
tible gradations  may  be  traced  "  from  the  black,  squat 
tribes  of  the  mountains  to  the  tall  olive-colored  Bramin, 
with  his  intellectual  brow,  calm  eyes,  and  high  but  nar- 
row head  ;  "  so  that  it  is  necessary  in  courts  of  justice  to 
ask  the  witnesses  whether  they  are  Santalis  or  Hindoos." 
Whether  a  heterogeneous  people,  such  as  the  inhabitants 
of  some  of  the  Polynesian  islands,  formed  by  the  cross- 
ing of  two  distinct  races,  with  few  or  no  pure  members 
left,  would  ever  become  homogeneous,  is  not  known  from 
direct  evidence.  But,  as  with  our  domesticated  animals, 
a  crossed  bi*eed  can  certainly,  in  the  course  of  a  few  gen- 
erations, be  fixed  and  made  uniform  by  careful  selection," 
we  may  infer  that  the  free  and  prolonged  intercrossing 
during  many  generations  of  a  heterogeneous  mixture 
would  supply  the  place  of  selection,  and  overcome  any 
tendency  to  reversion,  so  that  a  crossed  race  would  ulti- 
mately become  homogeneous,  though  it  might  not  par- 
take in  an  equal  degree  of  the  characters  of  the  two  par- 
ent-races. 

Of  all  the  differences  between  the  races  of  man,  the 
color  of  the  skin  is  tlie  most  conspicuous  and  one  of  the 
best  marked.  Differences  of  this  kind,  it  was  formerly 
thought,  could  be  accounted  for  by  long  exposure  under 
different  climates ;  but  Pallas  first  showed  that  this  view 
is  not  tenable,  and  he  has  been  followed  by  almost  all  an- 
thropologists.^^     The  view  has  been  rejected  chiefly  be- 

"  'The  Annals  of  Rural  Bengal,'  1SG8,  p.  134. 

'* '  The  Variation  of  Animals  and  Plants  under  Domestication,'  vol. 
li.  p.  95. 

3'  Pallas,  'Act.  Acad.  St.  Petersburg,'  HSO,  part  ii.  p.  69.  He  was 
followed  by  Rudolphi,  in  his  '  Bcytrage  zur  Anthropologic,'  1812.     An 


Chap.  VII.]  THE   RACES   OF  MAN.  233 

cause  the  distribution  of  the  variously-colored  races,  most 
of  whom  must  have  long  inhabited  their  present  homes, 
does  not  coincide  with  corresponding  differences  of  cli- 
mate. Weight  must  also  be  given  to  such  cases  as  that 
of  the  Dutch  families,  who,  as  we  hear  on  excellent  au- 
thority," haA^e  not  undergone  the  least  change  of  color, 
after  residing  for  three  centuries  in  South  Africa.  The 
uniform  appearance  in  various  parts  of  the  world  of  gyp- 
sies and  Jews,  though  the  uniformity  of  the  latter  has 
been  somwhat  exaggerated,^^  is  likewise  an  argument  on 
the  same  side.  A  very  damp  or  a  very  dry  atmosphere 
has  been  supposed  to  be  more  influential  in  modifying  the 
color  of  the  skin  than  mere  heat ;  but  as  D'Orbigny  in 
South  America,  and  Livingstone  in  Africa,  arrived  at  di- 
ametrically opjDOsite  conclusions  with  respect  to  dampness 
and  dryness,  any  conclusion  on  this  head  must  be  consid- 
ered as  very  doubtful." 

Various  facts,  which  I  have  elsewhere  given,  prove 
that  the  color  of  the  skin  and  hair  is  sometimes  corre- 
lated in  a  surprising  manner  with  a  complete  immunity 
from  the  action  of  certain  vegetable  poisons  and  from  the 
attacks  of  certain  parasites.  Hence  it  occurred  to  me, 
that  negroes  and  other  dark  races  might  have  acquired 
their  dark  tints  by  thedarker  individuals  escaping  during 
a  long  series  of  generations  from  the  deadly  influence  of 
the  miasmas  of  their  native  countries. 

I  afterward  found  that  the  same  idea  had  long  ago  oc- 
curred to  Dr.  Wells."    That  negroes,  and  even  mulattoes, 

excellent  summary  of  the  evidence  is  given  by  Godron,  'De  TEspece,' 
1859,  vol.  ii.  p.  246,  etc. 

*"  Sir  Andrew  Smith,  as  quoted  by  Knox, '  Races  of  Man,'  1850,  p.  473. 

*'  See  De  Quatrefages  on  this  head,  '  Revue  des  Cours  Scientifiques,' 
Oct.  11,  1868,  p.  731. 

^^  Livingstone's  '  Travels  and  Researches  in  S.  Africa,'  1857,  p.  338, 
329.     D'Orbigny,  as  quoted  by  Godron,  '  De  I'Espfece,'  vol.  ii.  p.  266. 

*^  See  a  paper  read  before  the  Royal  Soc.  in  1813,  and  published  io 
11 


234  THE   DESCENT   OF   MAX.  [Part  I. 

are  almost  completely  exempt  from  the  yellow  fever,  -which 
is  so  destructive  in  tropical  America,  has  long  been  known." 
They  likewise  escape  to  a  large  extent  the  fatal  intermit- 
tent fevers  that  prevail  along,  at  least,  2,600  miles  of  the 
shores  of  Africa,  and  which  annually  cause  one-fifth  of  tlie 
white  settlers  to  die,  and  another  fifth  to  return  home  in- 
valided." This  immunity  in  the  negro  seems  to  be  partly 
inherent,  depending  on  some  unknown  peculiarity  of  con- 
stitution, and  partly  the  result  of  acclimatization.  Pou- 
chet "  states  that  the  negro  regiments,  borrowed  from  the 
Viceroy  of  Egypt  for  the  Mexican  AYar,  which  had  been 
recruited  near  the  Soudan,  escaped  the  yellow  fever  al- 
most equally  w^ell  with  the  negroes  originally  brought 
from  various  parts  of  Africa,  and  accustomed  to  the  cli- 
mate of  the  West  Indies.  That  acclimatization  plays  a 
part  is  shown  by  the  many  cases  in  which  negroes,  af- 
ter having  resided  for  some  time  in  a  colder  climate, 
have  become  to  a  certain  extent  liable  to  tropical  fevers.*' 
The  nature  of  the  climate  under  which  the  white  races 
have  long  resided,  likewise  has  some  influence  on  them ; 
for,  during  the  fearful  epidemic  of  yellow  fever  in  Deme- 
rara  during  1837,  Dr.  Blair  found  that  the  death-rate  of 
the  immigrants  was  proportional  to  the  latitude  of  the 
country  whence  they  had  come.  With  the  negro  the  im- 
munity, as  far  as  it  is  the  result  of  acclimatization,  implies 

his  Essays  in  1818.  I  have  givep  an  account  of  Dr.  Wells's  views  in  the 
Historical  Sketch  (p.  xvi.)  to  my  '  Origin  of  Species.'  Various  cases  of 
color  correlated  with  constitutional  peculiarities  are  given  in  my  "Va- 
riation of  Animals  under  Domestication,'  vol.  ii.  pp.  227,  333. 

**  See,  for  instance,  Nott  and  Gliddon,  '  Types  of  Mankind,'  p.  68. 

*^  Major  Tulloch,  in  a  paper  read  before  the  Statistical  Society,  April 
20,  1840,  and  given  in  the  '  Athenajum.'  1840,  p.  353. 

"«  '  The  Plurality  of  the  Human  Race  '  (translat.),  1864,  p.  60. 

*^  Quatrefages,  'Unite  de  I'Espcce  Ilumaine,'  1861,  p.  205.  AVaitz, 
'  Introduct.  to  Anthropology,'  translat.  vol.  i.  1863,  p.  124.  Lit'ingstone 
gives  analogous  cases  in  bis  '  Travels.' 


Chap.  VII.]  '      THE   RACES  OF  MAN.  235 

exposure  during  a  prodigious  length  of  time;  for  the 
aborigines  of  tropical  America,  who  have  resided  there 
from  time  immemorial,  are  not  exempt  from  yellow  fever; 
and  the  Rev.  B.  Tristram  states  that  there  are  districts  in 
Northern  Africa  which  ihe  native  inhabitants  are  com- 
pelled annually  to  leave,  though  the  negroes  can  remain 
with  safety. 

That  the  immunity  of  the  negro  is  in  any  degree  cor- 
related with  the  color  of  his  skin  is  a  mere  conjecture  : 
it  may  be  correlated  with  some  difference  in  liis  blood, 
nervous  system,  or  other  tissues.  Nevertheless,  from  the 
facts  above  alluded  to,  and  from  some  connection  appar- 
ently existing  between  complexion  and  a  tendency  to  con- 
sumption, the  conjecture  seemed  to  me  not  improbable. 
Consequently  I  endeavored,  with  but  little  success,"  to 

*^  In  the  spring  of  1862  I  obtained  permission  from  the  Director- 
General  of  the  Medical  Department  of  the  Army,  to  transmit  to  the  sur- 
geons of  the  various  regiments  on  foreign  service  a  blank  table,  with  the 
following  appended  remarks,  but  I  have  received  no  returns  :  "As  several 
well-marked  cases  have  been  recorded  with  our  domestic  animals  of  a  re- 
lation between  the  color  of  the  dermal  appendages  and  the  constitution  ; 
and  it  being  notorious  that  there  is  some  limited  degree  of  relation  be- 
tween the  color  of  the  races  of  man  and  the  climate  inhabited  by  them, 
the  following  investigation  seems  worth  consideration,  namely,  whether 
there  is  any  relation  in  Europeans  between  the  color  of  their  hair  and 
their  liability  to  the  diseases  of  the  tropical  countries.  If  the  surgeons 
of  the  several  regiments,  when  stationed  in  unhealthy  tropical  districts, 
would  be  so  good  as  first  to  count,  as  a  standard  of  comparison,  how 
many  men,  in  the  force  whence  the  sick  are  drawn,  have  dark  and  light 
colored  hair,  and  hair  of  intermediate  or  doubtful  tints ;  and  if  a  similar 
account  were  kept  by  the  same  medical  gentlemen  of  all  the  men  who 
suffered  from  malarious  and  yellow  fevers,  or  from  dysentery,  it  would 
soon  be  apparent,  after  some  thousand  cases  had  been  tabulated,  whether 
there  exists  any  relation  between  the  color  of  the  hair  and  constitutional 
liability  to  tropical  diseases.  Perhaps  no  such  relation  would  be  discov- 
ered, but  the  investigation  is  well  worth  making.  In  case  any  positive 
result  were  obtained,  it  might  be  of  some  practical  use  in  selecting  men 
for  any  particular  service.     Theoretically  the  result  would  be  of  high 


236  THE   DESCENT   OF   MAN  [Part  I. 

ascertain  how  far  it  held  good.  The  late  Dr.  Daniell, 
who  had  long  lived  on  the  \Vest  Coast  of  Africa,  told  me 
that  he  did  not  believe  in  any  such  relation.  He  was 
himself  unusually  fair,  and  had  withstood  the  climate  in 
a  wonderful  manner.  When  he  first  arrived  as  a  boy  on 
the  coast,  an  old  and  experienced  negro  chief  predicted 
from  his  appearance  that  this  would  prove  the  case.  Dr. 
JN'icholson,  of  Antigua,  after  having  attended  to  this  sub- 
ject, wrote  to  me  that  he  did  not  think  that  dark-colored 
Europeans  escaped  the  yellow  fever  better  than  those  that 
were  light-colored.  Mr.  J.  M.  Harris  altogether  denies" 
that  Europeans  with  dark  hair  withstand  a  hot  climate 
better  than  other  men;  on  the  contrary,  experience  has 
taught  him,  in  making  a  selection  of  men  for  service  on 
the  coast  of  Africa,  to  choose  those  with  red  hair.  As  far, 
therefore,  as  these  slight  indications  serve,  there  seems  no 
foundation  for  the  hypothesis,  Avhich  has  been  accepted  by 
several  writers,  that  the  color  of  the  black  races  may  have 
resulted  from  darker  and  darker  individuals  having  sur- 
vived in  greater  numbers,  during  their  exposure  to  the 
fever-generating  miasmas  of  their  native  countries. 

Although  with  our  present  knowledge  we  cannot  ac- 
count for  the  strongly-marked  differences  in  color  between 
the  races  of  man,  either  through  correlation  with  consti- 
tutional peculiarities,  or  through  the  direct  action  of  cli- 
mate ;  yet  we  must  not  quite  ignore  the  latter  agency,  for 
there  is  good  reason  to  believe  that  some  inherited  effect 
is  thus  produced.^" 

interest,  as  indicating  one  means  by  which  a  race  of  men  inhabiting  from 
a  remote  period  an  unhealthy  tropical  climate,  might  have  become  dark- 
colored  by  the  better  preservation  of  dark-haired  or  dark-complexioned 
individuals  during  a  long  succession  of  generations." 

^'  'Anthropological  Review,'  Jan.  1866,  p.  xxl. 

^  See,  for  instance,  Quatrefages  ('  Revue  des  Cours  Scientifiques,' 
Oct.  10,  1868,  p.  724)  on  the  effects  of  residence  in  Abyssinia  and  Arabia, 
and  other  analogous  cases.     Dr.  Rolle  (Der  Mensch,  seine  Abstammung, 


Chap.  VII.]  THE   RACES   OF   MAN.  237 

We  have  seen  in  our  third  chaptei'  that  the  conditions 
of  life,  such  as  abundant  food  and  general  comfort,  affect 
in  a  direct  manner  the  develo^^ment  of  the  bodily  frame, 
the  effects  being  transmitted.  Through  the  combined  in- 
fluences of  climate  and  changed  habits  of  life,  European 
settlers  in  the  United  States  undergo,  as  is  generally  ad- 
mitted, a  slight  but  extraordinarily  rapid  change  of  ap- 
pearance. There  is,  also,  a  considerable  body  of  evidence 
showing  that  in  the  Southern  States  the  house-slaves  of 
the  third  generation  present  a  markedly  diffei-ent  aj^pear- 
ance  from  the  field-slaves." 

If,  however,  we  look  to  the  races  of  man,  as  distributed 
over  the  world,  we  must  infer  that  their  characteristic 
differences  cannot  be  accounted  for  by  the  direct  action 
of  different  conditions  of  life,  even  after  exposure  to  them 
for  an  enormous  period  of  time.  The  Esquimaux  live  ex- 
clusively on  animal  food ;  they  are  clothed  in  thick  fur, 
'  and  are  exposed  to  intense  cold  and  to  prolonged  dark- 
ness ;  yet  they  do  not  differ  in  any  extreme  degree  from 
the  inhabitants  of  Southern  China,  who  live  entirely  on 
vegetable  food  and  are  exposed  almost  naked  to  a  hot, 
glaring  climate.  The  unclothed  Fuegians  live  on  the 
marine  productions  of  their  inhospitable  shores ;  the  Bo- 
tocudos  of  Brazil  wander  about  the  hot  forests  of  the  in- 
terior and  live  chiefly  on  vegetable  productions  ;  yet  these 
tribes  resemble  each  other  so  closely  that  the  Fuegians  on 
board  the  "  Beagle "  were  mistaken  by  some  Brazilians 
for  Botocudos.    The  Botocudos,  again,  as  well  as  the  other 

etc.,  1865,  s.  99)  states,  on  the  authority  of  Khanikof,  that  the  greater 
number  of  German  famUies  settled  in  Georgia  have  acquired  in  the  course 
of  two  generations  dark  hair  and  eyes.  Mr.  D.  Forbes  informs  me  that 
the  Quichuas  in  the  Andes  vary  greatly  in  color,  according  to  the  posi- 
tion of  the  valleys  inhabited  by  them. 

^'  Harlan,  '  Medical  Researches,'  p.  532.  Quatrefages  (Unite  de 
I'Espece  H>'maine,'  1801,  p.  128)  has  collected  much  evidence  on  this 
head. 


238  THE   DESCENT   OF   MAX.  [Part  I. 

inhabitants  of  tropical  America,  are  Avholly  different  from 
the  Xegroes  who  inhabit  the  opposite  shores  of  the  At- 
lantic, are  exposed  to  a  nearly  similar  climate,  and  follow 
nearly  the  same  habits  of  life. 

Nor  can  the  differences  between  the  races  of  man  be 
accounted  for,  except  to  a  quite  insignificant  degree,  by 
the  inherited  effects  of  the  increased  or  decreased  use  of 
parts.  IMen  who  habitually  live  in  canoes  may  have  their 
legs  somewhat  stunted ;  those  who  inhabit  lofty  regions 
have  their  chests  enlarged;  and  those  who  constantly  use 
certain  sense-organs  have  the  cavities  in  which  they  are 
lodged  somewhat  increased  in  size,  and  their  features  con- 
sequently a  little  modified.  With  civilized  nations,  the 
reduced  size  of  the  jaws  from  lessened  use,  the  habitual 
play  of  difterent  muscles  serving  to  express  different  emo- 
tions, and  the  increased  size  of  the  brain  from  greater  in- 
tellectual activity,  have  together  produced  a  considerable 
effect  on  their  general  appearance,  in  comparison  with  ■ 
savages."  It  is  also  possible  that  increased  bodily  stature, 
with  no  corresponding  increase  in  the  size  of  the  brain, 
may  have  given  to  some  races  (judging  from  the  pre- 
viously adduced  cases  of  the  rabbits)  an  elongated  skull 
of  the  dolichocephalic  type. 

Lastly,  the  little-understood  principle  of  correlation 
will  almost  certainly  have  come  into  action,  as  in  the  case 
of  great  muscular  development  and  strongly-projecting 
supra-orbital  ridges.  It  is  not  improbable  that  the  texture 
of  the  hair,  which  differs  much  in  the  different  races,  may 
stand  in  some  kind  of  correlation  with  the  structure  of 
the  skin ;  for  the  color  of  the  hair  and  skin  are  certainly 
correlated,  as  is  its  color  and  texture  with  the  Mandans.*' 

''  See  Prof.  Schaaff hausen,  translat.  in  '  Anthropological  Review,' 
Oct.  1868,  p.  429. 

"  Mr.  Catlin  states  ('North  American  Indians,'  3d  edit.  1842,  vol.  i.  p. 
49)  that,   in  the  whole  tribe  of  the  Mandans,  about  one  in  ten  or  twelve 


Chap.  VII.]    '  THE   RACES  OF  MAN.  239 

The  color  of  the  skin  and  the  odor  emitted  by  it  are  like- 
wise in  some  manner  connected.  With  the  breeds  of 
sheep  the  number  of  hairs  within  a  given  space  and  the 
number  of  the  excretory  pores  stand  in  some  relation  to 
each  other."  If  we  may  judge  from  the  analogy  of  our 
domesticated  animals,  many  modifications  of  structure  in 
man  probably  come  under  this  principle  of  correlated 
growth. 

We  have  now  seen  that  the  characteristic  differences 
between  the  races  of  man  cannot  be  accounted  for  in  a 
satisfactory  manner  by  the  direct  action  of  the  conditions 
of  life,  nor  by  the  effects  of  the  continued  use  of  parts,  nor 
through  the  principle  of  correlation.  We  are  therefore 
led  to  inquire  whether  slight  individual  differences,  to 
which  man  is  eminently  liable,  may  not  have  been  pre- 
served and  augmented  during  a  long  series  of  generations 
through  natural  selection.  But  here  we  are  at  once  met 
by  the  objection  that  beneficial  variations  alone  can  be 
thus  preserved ;  and  as  far  as  we  are  enabled  to  judge 
(although  always  liable  to  error  on  this  head)  not  one  of 
the  external  differences  between  the  races  of  man  are  of 
any  direct  or  special  service  to  him.  The  intellectual  and 
moral  or  social  faculties  must  of  course  be  excepted  from 
this  remark ;  but  differences  in  these  faculties  can  have 
had  little  or  no  influence  on  external  characters.  The 
variability  of  all  the  characteristic  differences  between 
the  races,  before  referred  to,  likewise  indicates  that  these 
differences  cannot  be  of  much  importance ;  for,  had  they 

of  the  members  of  all  ages  and  both  sexes  have  bright  silvery  gray  hair, 
which  is  hereditary.  Now  this  hair  is  as  coarse  and  harsh  as  that  of  a 
horse's  mane,  while  the  hair  of  other  colors  is  fine  and  soft. 

^*  On  the  odor  of  the  skin,  Godron,  'Sur  TEspfece,'  torn.  ii.  p.  217. 
On  the  pores  in  the  skin,  Dr.  Wilckens,  '  Die  Aufgaben  der  landwirth. 
Zootechnik,'  1869,  s.  T. 


240  THE   DESCENT   OF  MAX.  [Part  I. 

been  important,  they  would  long  ago  have  been  either 
fixed  and  preserved,  or  eliminated.  In  this  respect  man 
resembles  those  forms,  called  by  naturalists  protean  or 
polymorphic,  Avhich  have  remained  extremely  variable, 
owing,  as  it  seems,  to  their  variations  being  of  an  indif- 
ferent nature,  and  consequently  to  their  having  escaped 
the  action  of  natural  selection. 

We  have  thus  far  been  bafHed  in  all  our  attempts  to 
account  for  the  differences  between  the  races  of  man  ;  but 
there  remains  one  important  agency,  namely,  Sexual  Selec- 
tion, which  appears  to  have  acted  as  powerfully  on  man 
as  on  many  other  animals.  I  do  not  intend  to  assert  that 
sexual  selection  will  account  for  all  the  differences  be- 
tween the  races.  An  unexplained  residuum  is  left,  about 
Avhich  we  can  in  our  ignorance  only  say  that,  as  individ- 
uals are  continually  born  with,  for  instance,  heads  a  little 
rounder  or  narrower,  and  with  noses  a  little  longer  or 
shorter,  such  slight  differences  might  become  fixed  and 
uniform,  if  the  unknown  agencies  which  induced  them 
were  to  act  in  a  more  constant  manner,  aided  by  long-con- 
tinued intercrossing.  Such  modifications  come  under  the 
provisional  class,  alluded  to  in  our  fourth  chapter,  which 
for  the  want  of  a  better  term  have  been  called  sponta- 
neous variations.  Nor  do  I  pretend  that  the  effects  of 
sexual  selection  can  be  indicated  with  scientific  precision ; 
but  it  can  be  shown  that  it  would  be  an  inexplicable  fact 
if  man  had  not  been  modified  by  this  agency,  which  has 
acted  so  powerfully  on  innumerable  animals,  both  high 
and  low  in  the  scale.  It  can  further  be  shown  that  the 
differences  between  the  races  of  man,  as  in  color,  hairi- 
ness, form  of  features,  etc.,  are  of  the  nature  which  it 
might  have  been  expected  would  have  been  acted  on  by 
sexual  selection.  But  in  order  to  treat  this  subject  in  a 
fitting  manner,  I  have  found  it  necessary  to  pass  the 
whole  animal  kingdom  in   review ;   I  have  therefore  dc- 


Chap.  VII.]  THE   RACES   OF   MAN.  241 

voted  to  it  the  Second  Part  of  this  work.  At  the  close  I 
shall  return  to  man,  and,  after  attempting  to  show  how 
far  he  has  been  modified  through  sexual  selection,  will 
give  a  brief  summary  of  the  chapters  in  this  First  Part 


PART  II. 

SEXUAL    SELECTION. 


SEXUAL    SELECTIO:^. 


CHAPTER  VIII. 

PRINCIPLES    OF    SEXUAL    SELECTIOK". 

Secondary  Sexual  Characters.  —  Sexual  Selection. — Manner  of  Action. — 
Excess  of  Males. — Polygamy. —  The  Male  alone  generally  modified 
through  Sexual  Selection. — Eagerness  of  the  Male. — Variability  of 
the  Male. — Choice  exerted  by  the  Female. — Sexual  compared  with 
Natural  Selection. — Inheritance,  at  Corresponding  Periods  of  Life,  at 
Corresponding  Seasons  of  the  Year,  and  as  limited  by  Sex. — Eolations 
between  the  Several  Forms  of  Inheritance. — Causes  why  one  Sex  and 
the  Young  are  not  modified  thiough  Sexual  Selection. — Supplement  on 
the  Proportional  Numbers  of  the  two  Sexes  throughout  the  Animal 
Kingdom. — On  the  Limitation  of  the  Numbers  of  the  two  Sexes 
through  Natural  Selection. 

"With  animals  which  have  their  sexes  separated,  the 
males  necessarily  differ  from  the  females  in  their  organs 
of  reproduction  ;  and  these  afford  the  primary  sexual  char- 
acters. But  the  sexes  often  differ  in  what  Hunter  has 
called  secondary  sexual  characters,  which  are  not  directly 
connected  with  the  act  of  reproduction ;  for  instance,  in 
the  male  possessing  certain  organs  of  sense  or  locomotion, 
of  which  the  female  is  quite  destitute,  or  in  having  them 
more  highly  developed,  in  order  that  he  may  readily  find 
or  reach  her ;  or  again,  in  the  male  having  special  organs 
of  prehension  so  as  to  hold  her  securely.  These  latter 
organs  of  infinitely-diversified  kinds  graduate  into,  and  in 
some  cases  can  hardly  be  distinguished  from,  those  which 


246  THE  PRIXCIPLES  OF  [Part  n. 

are  commonly  ranked  as  primary,  such  as  the  complex  ap- 
pendages at  the  apex  of  the  abdomen  in  male  insects. 
Unless  indeed  we  confine  the  term  "  primary "  to  the  re- 
productive glands,  it  is  scarcely  possible  to  decide,  as  far 
as  the  organs  of  prehension  are  concerned,  which  ought 
to  be  called  primary  and  which  secondary. 

The  female  often  differs  from  the  male  in  having  or- 
gans for  the  nourishment  or  protection  of  her  young,  as 
the  mammary  glands  of  mammals,  and  the  abdominal 
sacks  of  the  marsupials.  The  male,  also,  in  some  few 
cases  differs  from  the  female  in  possessing  analogous  or- 
gans, as  the  receptacles  for  the  ova  possessed  by  the 
males  of  certain  fishes,  and  those  temporarily  developed 
in  certain  male  frogs.  Female  bees  have  a  special  appa- 
ratus for  collecting  and  carrying  pollen,  and  their  oviposi- 
tor is  modified  into  a  sting  for  the  defence  of  their  larvae 
and  the  community.  In  the  females  of  many  insects  the 
ovipositor  is  modified  in  the  most  complex  manner  for  the 
safe  placing  of  the  eggs.  Numerous  similar  cases  could 
be  given,  but  they  do  not  here  concern  us.  There  are, 
however,  other  sexual  difterences  quite  disconnected  with 
the  primary  organs  with  which  we  are  more  especially 
concerned — such  as  the  greater  size,  strength,  and  pug- 
nacity of  the  male,  his  weapons  of  oftence  or  means  of 
defence  against  rivals,  his  gaudy  coloring  and  various 
ornaments,  his  power  of  song,  and  other  such  charac- 
ters. 

Besides  the  foregoing  primary  and  secondary  sexual 
differences,  the  male  and  female  sometimes  differ  in  struct- 
ures connected  with  difterent  habits  of  life,  and  not  at  all, 
or  only  indirectly,  I'eluted  to  the  reproductive  functions. 
Thus  the  females  of  certain  flies  (Culicida;  and  Tabanidce) 
are  blood-suckers,  while  the  males  live  on  flowers  and 
have  their  mouths  destitute  of  mandibles.*     The  males 

'  Westwood,  'Modem  Class,  of  Insects,'  vol.  ii.    1840,  p.  541.     In 


Chap.  VIII.]  SEXUAL  SELECTION.  2i1 

alone  of  certain  moths  and  of  some  crustaceans  (e.  g.,  Ta- 
nais)  have  imperfect,  closed  mouths,  and  cannot  feed. 
The  complemental  males  of  certain  Cirripedes  live  like 
epiphytic  plants  either  on  the  female  or  hermaphi'odite 
form,  and  are  destitute  of  a  mouth  and  prehensile  limbs. 
In  these  cases  it  is  the  male  which  has  been  modified  and 
has  lost  certain  important  organs,  which  the  other  mem- 
bers of  the  same  group  possess.  In  otlier  cases  it  is  the 
female  which  has  lost  such  parts  ;  for  instance,  the  female 
glowworm  is  destitute  of  wings,  as  are  many  female 
moths,  some  of  which  never  leave  their  cocoons.  Many 
female  parasitic  crustaceans  have  lost  their  natatory  legs. 
In  some  weevil-beetles  (Curculionidce)  there  is  a  great 
difference  between  the  male  and  female  in  the  lensrth  of 
the  rostrum  or  snout ;  ^  but  the  meaning  of  this,  and 
of  many  analogous  differences,  is  not  at  all  understood. 
Differences  of  structure  between  the  two  sexes  in  relation 
to  different  habits  of  life  are  generally  confined  to  the 
lower  animals  ;  but  with  some  few  birds  the  beak  of  the 
male  differs  from  that  of  the  female.  'No  doubt  in  most, 
but  apparently  not  in  all  these  cases,  the  differences  are 
indirectly  connected  with  the  propagation  of  the  species  : 
thus  a  female  which  has  to  nourish  a  multitude  of  ova 
will  require  more  food  than  the  male,  and  consequently 
will  require  special  means  for  procuring  it.  A  male  ani- 
mal which  lived  for  a  very  short  time  might  without  det- 
riment lose  through  disuse  its  organs  for  procuring  food  ; 
but  he  would  retain  his  locomotive  organs  in  a  perfect 
state,  so  that  he  might  reach  the  female.  The  female,  on 
the  other  hand,  might  safely  lose  her  organs  for  flying, 
swimming,  or  walking,  if  she  gradually  acquired  habits 
which  rendered  such  powers  useless. 

regard  to  the  statement  about  Tanais,  mentioned  below,  I  am  indebted  to 
Fritz  Midler. 

*  Kirby  and  Spence, '  Introduction  to  Entomology,'  voL  iii.  1820,  p.  809. 


248  THE  PRINCIPLES  OF  [Pakt  H. 

We  are,  however,  here  concerned  only  with  that  kind 
of  selection  which  I  have  called  sexual  selection.  This 
dejiends  on  the  advantage  which  certain  individuals  have 
over  other  individuals  of  the  same  sex  and  species,  in  ex- 
clusive relation  to  reproduction.  When  the  two  sexes 
differ  in  structure  in  relation  to  different  habits  of  life,  as 
in  the  cases  above  mentioned,  they  have  no  doubt  been 
modified  through  natural  selection,  accompanied  by  inher- 
itance limited  to  one  and  the  same  sex.  So,  again,  the 
primary  sexual  organs,  and  those  for  nourishing  or  pro- 
tecting the  young,  come  under  this  same  head  ;  for  those 
individuals  which  generated  or  nourished  their  offspring 
best,  would  leave,  cceteris  paribus,  the  greatest  number  to 
inherit  their  superiority ;  while  those  w^hich  generated  or 
nourished  their  offspring  badly,  would  leave  but  few  to 
inherit  their  weaker  powers.  As  the  male  has  to  search 
for  the  female,  he  requires  for  this  purpose  organs  of  sense 
and  locomotion,  but  if  these  organs  are  necessary  for  the 
other  purposes  of  life,  as  is  generally  the  case,  they  will 
have  been  developed  through  natural  selection.  When 
the  male  has  found  the  female  he  sometimes  absolutely 
requires  prehensile  organs  to  hold  her;  thus  Dr.  Wallace 
informs  me  that  the  males  of  certain  moths  cannot  unite 
wath  the  females  if  their  tarsi  or  feet  are  broken.  The 
males  of  many  oceanic  crustaceans  have  their  legs  and 
antennre  modified  in  an  extraordinary  manner  for  the  pre- 
hension of  the  female ;  hence  we  may  suspect  that  owing 
to  these  animals  being  washed  about  by  the  waves  of  the 
open  sea,  they  absolutely  require  these  organs  in  order  to 
propagate  their  kind,  and  if  so  their  development  will 
have  been  the  result  of  ordinary  or  natural  selection. 

When  the  two  sexes  follow  exactly  the  same  habits 
of  life,  and  the  male  has  more  highly-developed  sense  or 
locomotive  organs  than  the  female,  it  may  be  that  these 
in  their  perfected  state  are  indispensable  to  the  male  for 


Chap.  VIII.]  SEXUAL   SELECTION.  249 

finding  the  female ;  but  in  the  vast  majority  of  cases,  they 
serve  only  to  give  one  male  an  advantage  over  another, 
for  the  less  well-endowed  males,  if  time  were  allowed  them, 
would  succeed  in  pairing  with  the  females;  and  they 
would  in  all  other  respects,  judging  from  the  structure 
of  the  female,  be  equally  well  adapted  for  their  ordinary 
habits  of  life.  In  such  cases  sexual  selection  must  have 
come  into  action,  for  the  males  have  acquired  their  pres- 
ent structure,  not  from  being  better  fitted  to  survive  in 
the  struggle  for  existence,  but  from  having  gained  an  ad- 
vantage over  other  males,  and  from  having  transmitted 
this  advantage  to  their  male  ofispring  alone.  It  was  the 
importance  of  this  distinction  which  led  me  to  designate 
this  form  of  selection  as  sexual  selection.  So,  again,  if  the 
chief  service  rendei'ed  to  the  male  by  his  prehensile  organs 
is  to  prevent  the  escape  of  the  female  before  the  arrival 
of  other  males,  or  when  assaulted  by  them,  these  organs 
will  have  been  perfected  through  sexual  selection,  that  is, 
by  the  advantage  acquired  by  certain  males  over  their 
rivals.  But  in  most  cases  it  is  scarcely  possible  to  distin- 
guish between  the  effects  of  natural  and  sexual  selection. 
Whole  chapters  could  easily  be  filled  with  details  on  the 
differences  between  the  sexes  in  their  sensory,  locomotive, 
and  prehensile  organs.  As,  however,  these  structures  are 
not  more  interesting  than  others  adapted  for  the  ordinary 
purposes  of  life,  I  shall  almost  pass  them  over,  giving  only 
a  few  instances  under  each  class. 

There  are  many  other  structures  and  instincts  which 
must  have  been  developed  through  sexual  selection — such 
as  the  weapons  of  offence  and  the  means  of  defence  pos- 
sessed by  the  males  for  fighting  with  and  driving  away 
their  rivals — their  courage  and  pugnacity — their  orna- 
ments of  many  kinds — their  organs  for  producing  vocal 
or  instrumental  music — and  their  glands  for  emitting 
odors  ;  most  of  these  latter  structures  serving  only  to  al- 


250  THE   rraXCIPLES  OF  [Part  II. 

lure  or  excite  the  female.  That  these  characters  are  the 
result  of  sexual  and  not  of  ordinary  selection  is  clear,  as 
unarmed,  unornamcnted,  or  unattractive  mak'S  would  suc- 
ceed equally  well  in  the  battle  for  life  and  in  leaving  a 
numerous  progeny,  if  better-endowed  males  were  not 
present.  We  may  infer  that  tliis  would  be  the  case,  for 
the  females,  which  are  unarmed  and  unornamcnted,  are 
able  to  survive  and  procreate  their  kind.  Secondary  sex- 
ual characters  of  the  kind  just  referred  to,  will  be  fully 
discussed  in  the  following  chapters,  as  they  are  in  many 
resjiects  interesting,  but  more  especially  as  they  depend 
on  the  will,  choice,  and  I'ivalry  of  the  individuals  of  either 
sex.  When  we  behold  two  males  fighting  for  the  posses- 
sion of  the  female  ;  or  several  male  birds  displaying  their 
gorgeous  plumage,  and  performing  the  strangest  antics 
before  an  assembled  body  of  females,  we  cannot  doubt 
that,  though  led  by  instinct,  they  know  what  they  are 
about,  and  consciously  exert  their  mental  and  bodily 
powers. 

In  the  same  manner  as  man  can  improve  the  breed  of 
his  game-cocks  by  the  selection  of  those  birds  which  are 
victorious  in  the  cockpit,  so  it  appears  that  the  strongest 
and  most  vigorous  males,  or  those  provided  with  the  best 
weapons,  have  prevailed  under  Nature,  and  have  led  to  the 
improvement  of  the  natural  breed  or  species.  Through 
repeated  deadly  contests,  a  slight  degree  of  variability, 
if  it  led  to  some  advantage,  however  slight,  would  suflice 
for  the  work  of  sexual  selection ;  and  it  is  certain  that 
secondary  sexual  characters  are  eminently  variable.  In 
the  same  manner  as  man  can  give  beauty,  according  to 
his  standard  of  taste,  to  his  male  poultry — can  give  to  the 
Sebright  bantam  a  new  and  elegant  plumage,  an  erect  and 
peculiar  carriage — so  it  appears  that  in  a  state  of  nature 
female  birds,  by  having  long  selected  the  more  attractive 
males,  have  added  to  their  beauty.     No  doubt  this  im- 


Chap.  YIII.]  SEXUAL   SELECTION.  251 

plies  powers  of  discrimination  and  taste  on  the  part  of  the 
female  which  will  at  first  appear  extremely  improbable ; 
but  I  liope  hereafter  to  show  that  this  is  not  the  case. 

From  our  ignorance  on  several  points,  the  precise  man- 
ner in  which  sexual  selection  acts  is  to  a  certain  extent 
uncertain.  Nevertheless  if  those  naturalists  who  already 
believe  in  the  mutability  of  species,  will  read  the  following 
chapters,  they  will,  I  think,  agree  with  me  that  sexual  se- 
lection has  played  an  important  part  in  the  history  of  the 
organic  world.  It  is  certain  that  with  almost  all  animals 
there  is  a  struggle  between  the  males  for  the  possession  of 
the  female.  This  fact  is  so  notorious  that  it  would  be  su- 
perfluous to  give  instances.  Hence  the  females,  supposing 
that  their  mental  capacity  sufficed  for  the  exertion  of  a 
choice,  could  select  one  out  of  several  males.  But  in  nu- 
merous cases  it  appears  as  if  it  had  been  specially  arranged 
that  there  should  be  a  struggle  between  many  males. 
Thus  with  migratory  birds,  the  males  generally  arrive  be- 
fore the  females  at  their  place  of  breeding,  so  that  many 
males  are  ready  to  contend  for  each  female.  The  bird- 
catchers  assert  that  this  is  invariably  the  case  with  the 
nightingale  and  blackcap,  as  I  am  informed  by  Mr.  Jenner 
Weir,  who  confirms  the  statement  with  respect  to  the  lat- 
ter species. 

Mr.  Swaysland,  of  Brighton,  who  has  been  in  the  habit, 
during  the  last  forty  years,  of  catching  our  migratory 
birds  on  their  first  arrival,  writes  to  me  that  he  has  never 
known  the  females  of  any  species  to  arrive  before  their 
males.  During  one  spring  he  shot  thirty-nine  males  of 
Ray's  wagtail  {Budytes  Mali)  before  he  saw  a  single  fe- 
male. Mr.  Gould  has  ascertained  by  dissection,  as  he  in- 
forms me,  that  male  snipes  arrive  in  this  country  before 
the  females.  In  the  case  of  fish,  at  the  period  when  the 
salmon  ascend  our  rivers,  the  males  in  large  numbers  are 
ready  to  breed  before  the  females.     So  it  apparently  is 


252  THE  PRINCIPLES  OF  [Part  II. 

■with  frogs  and  toads.  Throughout  the  great  class  of  in- 
sects tlie  males  almost  always  emerge  from  the  pupal  state 
before  the  other  sex,  so  that  they  generally  swarm  for  a 
time  before  any  females  can  be  seen.'  The  cause  of  this 
difference  between  the  males  and  females  in  their  periods 
of  arrival  and  maturity  is  sufficiently  obvious.  Those  males 
which  annually  first  migrated  into  any  country,  or  which 
in  the  sjiring  were  first  ready  to  breed,  or  were  the  most 
eager,  would  leave  the  lai'gest  number  of  offspring ;  and 
these  would  tend  to  inherit  similar  instincts  and  constitu- 
tions. On  the  whole,  there  can  be  no  doubt  that  with  al- 
most all  animals,  in  which  the  sexes  are  separate,  there  is  a 
constantly  recurrent  struggle  between  the  males  for  the 
possession  of  the  females. 

Our  difficulty  in  regard  to  sexual  selection  lies  in  un- 
derstanding how  it  is  that  the  males  Avhich  conquer  other 
males,  or  those  which  prove  the  most  attractive  to  the  fe- 
males, leave  a  greater  number  of  offspring  to  inherit  their 
superiority  than  the  beaten  and  less  attractive  males. 
Unless  this  result  followed,  the  characters  which  gave  to 
certain  males  an  advantage  over  others,  could  not  be  per- 
fected and  augmented  through  sexual  selection.  When 
the  sexes  exist  in  exactly  equal  numbers,  the  worst-endowed 
males  will  ultimately  find  females  (excepting  where  polyg- 
amy prevails),  and  leave  as  many  offspring,  equally  well 
fitted  for  their  general  habits  of  life,  as  the  best-endowed 
males.  From  various  facts  and  considerations,  I  former- 
ly inferred  that  with  most  animals,  in  which  secondary 

^  Even  with  those  of  plants  in  which  the  sexes  are  separate,  the  male 
flowers  arc  generally  mature  before  the  female.  Many  hermaphrodite 
plants  arc,  as  first  shown  by  C.  K.  Sprengel,  dichogamous  ;  that  is,  their 
male  and  female  organs  are  not  ready  at  the  same  time,  so  that  they  can- 
not be  self-fertilized.  Now  with  such  plants  the  pollen  is  generally  ma- 
ture in  the  same  flower  before  the  stigma,  though  there  are  some  excep- 
tional species  in  which  the  female  organs  arc  mature  before  the  male. 


Chap.  VIII.]  SEXUAL  SELECTION.  253 

sexual  characters  were  well  developed,  the  males  considera- 
bly exceeded  the  females  in  number ;  and  this  does  hold 
good  in  some  few  cases.  If  the  males  were  to  the  females 
as  two  to  one,  or  as  three  to  two,  or  even  in  a  somewhat 
lower  ratio,  the  whole  aifair  would  be  simple :  for  the  bet- 
ter-armed or  more  attractive  males  would  leave  the  lar- 
gest number  of  offspring.  But  after  investigating,  as  far 
as  possible,  the  numerical  proportions  of  the  sexes,  I  do 
not  believe  that  any  great  inequality  in  number  commonly 
exists.  In  most  cases  sexual  selection  appears  to  have 
been  effective  in  the  following  manner : 

Let  us  take  any  species,  a  bird  for  instance,  and  di- 
vide the  females  inhabiting  a  district  into  two  equal 
bodies :  the  one  consisting  of  the  more  vigorous  and  bet- 
ter-nourished individuals,  and  the  other  of  the  less  vigor- 
ous and  healthy.  The  former,  there  can  be  little  doubt, 
would,  be  ready  to  breed  in  the  spring  before  the  others ; 
and  this  is  the  opinion  of  Mr.  Jenner  Weir,  who  has  dur- 
ing many  years  carefully  attended  to  the  habits  of  birds. 
There  can  also  be  no  doubt  that  the  most  vigorous, 
healthy,  and  best-nourished  females  would  on  an  average 
succeed  in  rearing  the  largest  number  of  offspring.  The 
males,  as  we  have  seen,  are  generally  ready  to  breed  be- 
fore the  females ;  of  the  males  the  strongest,  and  with 
some  species  the  best  armed,  drive  away  the  weaker 
males ;  and  the  former  would  then  unite  with  the  more 
vigorous  and  best-nourished  females,  as  these  are  the  first 
to  breed.  Such  vigorous  pairs  would  surely  rear  a  larger 
number  of  offspring  than  the  retarded  females,  which 
would  be  compelled,  supposing  the  sexes  to  be  numeri- 
cally equal,  to  unite  with  the  conquered  and  less  powerful 
males ;  and  this  is  all  that  is  wanted  to  add,  in  the  course 
of  successive  generations,  to  the  size,  strength,  and  cour- 
age of  the  males,  or  to  improve  their  weapons. 

But  in  a  multitude  of  cases  the  males  which  conquer 


25-t  THE   PRIXCIPLES   OF  [Part  II. 

.  other  males  do  not  obtain  possession  of  the  females,  in- 
dependently of  choice  on  the  part  of  the  latter.  The 
courtship  of  animals  is  hy  no  means  so  simple  and  short 
an  aflair  as  might  be  thought.  The  females  are  most  ex- 
»  cited  by,  or  prefer  pairing  with,  the  more  ornamented 
males,  or  those  which  are  the  best  songsters,  or  play  the 
best  antics ;  but  it  is  obviously  probable,  as  has  been 
actually  observed  in  some  cases,  that  they  would  at  the 
same  time  prefer  the  more  vigorous  and  lively  males,* 
Thus  the  more  vigorous  females,  which  are  the  first  to 
breed,  will  have  the  choice  of  many  males  ;  and  though 
they  may  not  always  select  the  strongest  or  best  armed, 
they  will  select  those  which  are  vigorous  and  well  armed, 
and  in  other  respects  the  most  attractive.  Such  early 
pairs  would  have  the  same  advantage  in  rearing  offspring 
on  the  female  side  as  above  explained,  and  nearly  the 
same  advantage  on  the  male  side.  And  this  apparently 
has  sufficed  during  a  long  course  of  generations  to  add  not 
only  to  the  strength  and  fighting-powers  of  the  males,  but 
likewise  to  their  various  ornaments  or  other  attractions. 

In  the  converse  and  much  rarer  case  of  the  males  se- 
lecting particular  females,  it  is  plain  that  those  which  were 
the  most  vigorous  and  had  conquered  others,  would  have 
the  freest  choice ;  and  it  is  almost  certain  that  they  would 
select  vigorous  as  well  as  attractive  females.  Such  pairs 
would  have  an  advantage  in  rearing  offspring,  more  es- 
pecially if  the  male  had  the  power  to  defend  the  female 
during  the  pairing-season,  as  occurs  with  some  of  the 
higher  animals,  or  aided  in  providing  for  the  young.  The 
same  principles  would  apply  if  both  sexes  mutually  pre- 
ferred and  selected  certain  individuals  of  the  opposite  sex ; 

*  I  have  received  information,  hereafter  to  be  given,  to  this  effect  with 
respect  to  poultry.  Even  with  birds,  such  as  pigeons,  which  pair  for  life, 
the  female,  as  I  hear  from  Mr.  Jcnner  Weir,  will  desert  her  mate  if  he  is 
injured  or  grows  weak. 


Chap,  yill.]  SEXUAL  SELECTIOX.  255 

supposing  that  they  selected  not  only  the  move  attractive, 
but  likewise  the  more  vigorous  individuals. 

Numerical  Proportion,  of  the  Two  Sexes. — I  have  re- 
marked that  sexual  selection  would  be  a  simple  affair  if 
the  males  considerably  exceeded  in  number  the  females. 
Hence  I  was  led  to  investigate,  as  far  as  I  could,  the  pro- 
portions between  the  two  sexes  of  as  many  animals  as 
possible ;  but  the  materials  are  scanty.  I  will  here  give 
only  a  brief  abstract  of  the  results,  retaining  the  details 
for  a  supplementary  discussion,  so  as  not  to  interfere  with 
the  course  of  my  argument.  Domesticated  animals  alone 
afford  the  opportunity  of  ascertaining  the  proportional 
numbers  at  birth ;  but  no  records  have  been  specially  kept 
for  this  purpose.  By  indirect  means,  however,  I  have  col- 
lected a  considerable  body  of  statistical  data,  from  v/hich 
it  appears  that  with  most  of  our  domestic  animals  the 
sexes  are  nearly  equal  at  birth.  Thus  with  race-horses, 
25,560  births  have  been  recorded  during  twenty-one  years, 
and  the  male  births  have  been  to  the  female  births  as  99.7 
to  100.  With  greyhounds  the  inequality  is  greater  than 
with  any  other  animal,  for  during  twelve  years,  out  of 
C,878  births,  the  male  births  have  been  as  11,0.1  to  100 
female  births.  It  is,  however,  in  some  degree  doubtful 
whether  it  is  safe  to  infer  that  the  same  proportional  num- 
bers would  hold  good  under  natural  conditions  as  under 
domestication ;  for  slight  and  unknown  differences  in  the 
conditions  affect  to  a  certain  extent  the  proportion  of  the 
sexes.  Thus  with  mankind,  the  male  births  in  England 
are  as  104.5,  in  Russia  as  108.9,  and  with  the  Jews  of 
Livonia  as  120  to  100  females.  The  proportion  is  also 
mysteriously  affected  by  the  circumstance  of  the  births 
being  legitimate  or  illegitimate. 

For  our  present  purpose  we  are  concerned  with  the 
proportion  of  the  sexes,  not  at  birth,  but  at  maturity,  and 


256  THE   PRINCIPLES   OF  [Part  11. 

this  ailds  anotlicr  element  of  doubt ;  for  it  is  a  ■well-ascer- 
tained fact  that  Avitli  man  a  considerably  larger  proportion 
of  males  than  of  females  die  before  or  during  birth,  and 
during  the  first  few  years  of  infancy.  So  it  almost  cer- 
tainly is  with  male  lambs,  and  so  it  may  be  with  the  males 
of  other  animals.  The  males  of  some  animals  kill  each 
other  by  fighting ;  or  they  drive  each  other  about  until 
they  become  greatly  emaciated.  They  must,  also,  while 
wandering  about  in  eager  searcli  for  the  females,  be  often 
exposed  to  various  dangers.  With  many  kinds  of  fish  the 
males  are  much  smaller  than  the  females,  and  they  are  be- 
lieved often  to  be  devoured  by  the  latter  or  by  other  fishes. 
With  some  birds  the  females  appear  to  die  in  larger  pro- 
portion than  the  males :  they  are  also  liable  to  be  de- 
stroyed on  their  nests,  or  while  in  charge  of  their  young. 
With  insects  the  female  larvae  are  often  larger  than  those 
of  the  males,  and  would  consequently  be  more  likely  to 
be  devoured :  in  some  cases  the  mature  females  are  less 
active  and  less  rapid  in  their  movements  than  the  males, 
and  would  not  be  so  well  able  to  escape  from  danger. 
Hence,  with  animals  in  a  state  of  nature,  in  order  to  judge 
of  the  proportions  of  the  sexes  at  maturity,  we  must  rely 
on  mere  estimation ;  and  this,  except  perhaps  when  the 
inequality  is  strongly  marked,  is  but  little  trustworthy. 
Nevertheless,  as  far  as  a  judgment  can  be  formed,  we  may 
conclude,  from  the  facts  given  in  the  supplement,  that  the 
males  of  some  few  mammals,  of  many  birds,  of  some  fish 
and  insects,  considerably  exceed  in  number  the  females. 

The  jjroportion  between  the  sexes  fluctuates  slightly 
during  successive  years :  thus  with  race-horses,  for  every 
100  females  born,  the  males  varied  from  107.1  in  one  year 
to  92.6  in  another  year,  and  with  greyhounds  from  116.3 
to  95.3.  But  had  lai'ger  numbers  been  tabulated  through- 
out a  more  extensive  area  than  England,  these  fluctuations 
would  probably  have  disappeared ;  and  such  as  they  are, 


Chap.  VIII.]  SEXUAL   SELECTION.  257 

they  would  hardly  suffice  to  lead  under  a  state  of  nature 
to  the  effective  action  of  sexual  selection.  Nevertheless 
with  some  few  wild  animals,  the  proportions  seem,  as 
shown  in  the  supplement,  to  fluctuate  either  during  differ- 
ent seasons  or  in  different  localities  in  a  sufficient  degree 
to  lead  to  such  action.  For  it  should  be  observed  that 
any  advantage  gained  during  certain  years  or  in  certain 
localities  by  those  males  which  were  able  to  conquer  other 
males,  or  were  the  most  attractive  to  the  females,  would 
probably  be  transmitted  to  the  offspring  and  would  not 
subsequently  be  eliminated.  During  the  succeeding  sea- 
sons, when  from  the  equality  of  the  sexes  every  male  was 
everywhere  able  to  procure  a  female,  the  stronger  or  more 
attractive  males  previously  produced  would  still  have  at 
least  as  good  a  chance  of  leaving  offspring  as  the  less 
strong  or  less  attractive. 

Folygaray. — ^The  practice  of  polygamy  leads  to  the 
same  results  as  would  follow  from  an  actual  inequality  in 
the  number  of  the  sexes  ;  for  if  each  male  secures  two  or 
more  females,  many  males  will  not  be  able  to  pair;  and 
the  latter  assuredly  will  be  the  weaker  or  less  attractive 
individuals.  Many  mammals  and  some  few  birds  are 
polygamous,  but  with  animals  belonging  to  the  lower 
classes  I  have  fomxd  no  evidence  of  this  habit.  The  intel- 
lectual powers  of  such  animals  are,  perhaps,  not  sufficient 
to  lead  them  to  collect  and  guard  a  harem  of  females. 
That  some  relation  exists  between  polygamy  and  the  de- 
velopment of  secondary  sexual  characters,  appears  nearly 
certain ;  and  this  supports  the  view  that  a  numerical  pre- 
ponderance of  males  would  be  eminently  favorable  to  the 
action  of  sexual  selection.  Nevertheless  many  animals, 
especially  birds,  which  are  strictly  monogamous,  display 
strongly-marked  secondary  sexual  characters ;  while  some 
few  animals,  which  are  polygamous,  are  not  thus  charac- 
terized. 

12 


258  THE   PRINCIPLES  OF  [Part  II. 

We  will  first  briefly  run  tlu'ougli  the  class  of  mammals, 
and  then  turn  to  birds.  The  gorilla  seems  to  be  a  polyg- 
amist,  and  the  male  diflers  considerably  from  the  female; 
so  it  is  with  some  baboons  which  live  in  herds  containing 
twice  as  many  adult  females  as  males.  In  South  America 
the  Mycetes  caraya  j^resents  well-marked  sexual  differ- 
ences in  color,  beard,  and  vocal  organs,  and  the  male  gen- 
erally lives  with  two  or  three  wives:  the  male  of  the 
Cebus  capucinus  differs  somewhat  from  the  female,  and 
appears  to  be  polygamous.'  Little  is  known  on  this  head 
with  respect  to  most  other  monkeys,  but  some  species  are 
strictly  monogamous.  The  ruminants  are  eminently  polyg- 
amous, and  they  more  frequently  present  sexual  differ- 
ences than  almost  any  other  group  of  mammals,  especially 
in  their  weapons,  but  likewise  in  other  characters.  Most 
deer,  cattle,  and  sheep,  are  polygamous ;  as  are  most  ante- 
lopes, though  some  of  the  latter  are  monogamous.  Sir 
Andrew  Smith,  in  speaking  of  the  antelopes  of  South 
Africa,  says  that  in  herds  of  about  a  dozen  there  was 
rarely  more  than  one  mature  male.  The  Asiatic  Antilope 
saiga  appears  to  be  the  most  inordinate  polygamist  in  the 
world  ;  for  Pallas  *  states  that  the  male  drives  away  all 
rivals,  and  collects  a  herd  of  about  a  hundred,  consisting 
of  females  and  kids :  the  female  is  hornless  and  has  softer 
hair,  but  docs  not  otherwise  differ  much  from  the  male. 
The  horse  is  polygamous,  but,  except  in  his  greater  size 
and  in  the  proportions  of  his  body,  differs  but  little  from 

'"  Ou  the  Gorilla,  Savage  and  Wyman,  '  Boston  Journal  of  Nat.  Ilist.' 
vol.  V.  1845-1847,  J).  423.  On  Cynocephalus,  Brehm,  'Illust.  Thierleben,' 
B.  i.  1864,  8.  77.  On  Mycetes,  Rengger,  '  Naturgesch. :  Siiugethicre  von 
Paraguay,'  1830,  s.  14,  20.     On  Cebus,  Brehm,  ibid.  s.  108. 

"Pallas,  '  Spicilegia  Zoolog.,  Fasc.  xii.  1777,  p.  29. ,  Sir  Andrew 
Smith,  'Illustrations  of  the  Zoology  of  South  Africa,'  1849,  pi.  20,  on  the 
Kobus.  Owen,  in  his  'Anatomy  of  Vertebrates'  (vol.  iii.  18G8,  p.  633), 
gives  a  table  incidentally  showing  which  species  of  Antelopes  pair  and 
which  are  gregarious. 


Chap.  VIII.]  SEXUAL   SELECTION.  259 

the  mare.  The  wild-boar,  in  his  great  tusks  and  some 
other  characters,  presents  well-marked  sexual  characters ; 
in  Europe  and  in  India  he  leads  a  solitary  life,  except  dur- 
inof  the  breeding-season:  but  at  this  season  he  consorts 
in  India  with  several  females,  as  Sir  W.  Elliot,  who  has 
had  large  experience  in  observing  this  animal,  believes : 
whether  this  holds  good  in  Europe  is  doubtful,  but  is  sup- 
ported by  some  statements.  The  adult  male  Indian  ele- 
phant, like  the  boar,  passes  much  of  his  time  in  solitude ; 
but  when  associating  with  others,  "  it  is  rare  to  find,"  as 
Dr.  Campbell  states,  "  more  than  one  male  with  a  whole 
herd  of  females."  The  larger  males  expel  or  kill  the 
smaller  and  weaker  oiies.  The  male  differs  from  the  fe- 
male by  his  immense  tusks  and  greater  size,  strength,  and 
endurance ;  so  great  is  the  difference  in  these  latter  re- 
spects, that  the  males  when  caught  are  valued  at  twenty 
per  cent,  above  the  females.'  With  other  pachydermatous 
animals  the  sexes  differ  very  little  or  not  at  all,  and  they 
are  not,  as  far  as  known,  polygamists.  Hardly  a  single 
species  among  the  Cheiroptera  and  Edentata,  or  in  the 
great  Orders  of  the  Rodents  and  Insectivora,  presents 
well-developed  secondary  sexual  differences;  and  I  can 
find  no  account  of  any  species  being  polygamous,  except- 
ing, perhaps,  the  common  rat,  the  males  of  which,  as  some 
rat-catchers  affirm, -live  with  several  females. 

The  lion  in  South  Africa,  as  I  hear  from  Sir  Andrew 
Smith,  sometimes  lives  with  a  single  female,  but  gener- 
ally with  more  than  one,  and,  in  one  case,  was  found  with 
as  many  as  five  females,  so  that  he  is  polygamous.  He  is, 
as  far  as  I  can  discover,  the  sole  polygaraist  in  the  whole 
group  of  the  terrestrial  Carnivora,  and  he  alone  presents 
well-marked  sexual  characters.     If,  however,  we  turn  to 

''Dr.  Campbell,  in  '  Proc.  Zoolog.  Soc'  1869,  p.  138.  See  also  an 
interesting  paper,  by  Lieut.  Johnstone,  in  'Proc.  Asiatic  Soc.  of  Bengal,' 
Mav,  1SG8 


260  THE  PRIXCIPLES   OF  [Part  II. 

the  marine  Carnivora,  tlio  case  is  widely  different ;  for 
many  species  of  seals  offer,  as  we-  shall  hereafter  see,  ex- 
traordinary sexual  differences,  and  they  are  eminently 
polygamous.  Thus  the  male  sea-elephant  of  the  Southern 
Ocean  always  possesses,  according  to  Peron,  several  fe- 
males, and  the  sea-lion  of  Forster  is  said  to  be  surrounded 
by  from  twenty  to  thirty  females.  In  the  North,  the 
male  sea-bear  of  Steller  is  accompanied  by  even  a  greater 
mmiber  of  females. 

With  respect  to  birds,  many  species,  the  sexes  of  which 
differ  greatly  from  each  other,  are  certainly  monogamous. 
In  Great  Britain  we  see  well-marked  sexual  differences  in, 
for  instance,  the  wild-duck,  which  pairs  with  a  single  fe- 
male, with  the  common  blackbuxl,  and  with  tlie  bullfinch, 
which  is  said  to  pair  for  life.  So  it  is,  as  I  am  informed 
by  Mr.  Wallace,  with  the  Chatterers  or  Cotingidse  of  South 
America,  and  numerous  other  birds.  In  several  groups  I 
have  not  been  able  to  discover  whether  the  species  are 
polygamous  or  monogamous.  Lesson  says  that  birds  of 
paradise,  so  remarkable  for  their  sexual  differences,  are 
polygamous,  but  Mr.  Wallace  doubts  whether  he  had  suf- 
ficient evidence.  Mr.  Salvin  informs  me  that  he  has  been 
led  to  believe  that  humming-birds  are  polygamous.  The 
male  widow-bird,  remarkable  for  his  caudal  plumes,  cer- 
tainly seems  to  be  a  polygamist.®  I  have  been  assured,  by 
Mr.  Jcnner  Weir  and  by  others,  that  three  starlings  not 
rarely  frequent  the  same  nest ;  but  whether  this  is  a  case 
of  polygamy  or  polyandry  has  not  been  ascertained. 

The  Gallinacea?  present  almost  as  strongly-marked 
sexual  differences  as  birds  of  paradise  or  humming-birds, 

8  'The  Ibis,'  vol.  iii.  1861,  p.  133,  on  the  rrogne  Widow-bird.  See 
also  on  the  Vidua  axillaris,  ibid.  vol.  ii.  ISGO,  p.  211.  On  the  polygamy 
of  the  Capercailzie  and  Great  Bustard,  see  L.  Lloyd,  '  Game  Birds  of 
Sweden,'  1807,  pp.  19,  128.  Montagu  and  Sclby  speak  of  the  Black 
Grouse  as  polygamous,  and  of  the  Red  Grouse  as  monogamous. 


Chap.  VIII.]  SEXUAL   SELECTION.  261 

and  many  of  the  species  are,  as  is  well  known,  polyga- 
mous ;  others  being  strictly  monogamous.  What  a  con- 
trast is  presented  between  the  sexes  by  the  polygamous 
peacock  or  pheasant,  and  the  monogamous  guinea-fowl 
or  partridge  !  Many  similar  cases  could  be  given,  as  in 
the  grouse-tribe,  in  which  the  males  of  the  polygamous 
capercailzie  and  black-cock  differ  greatly  from  the  fe- 
males ;  while  the  sexes  of  the  monogamous  red  grouse 
and  ptarmigan  differ  very  little.  Among  the  Cursores,  no 
great  number  of  species  offer  strongly-marked  sexual 
differences,  except  the  bustards,  and  the  great  bustard 
( Otis  tarda)  is  said  to  be  i^olygajtnous.  With  the  Gralla- 
tores,  extremely  few  species  differ  sexually,  but  the  ruff 
{Machetes  pugnax)  affords  a  strong  exception,  and  this 
species  is  believed  by  Montagu  to  be  a  polygamist.  Hence 
it  appears  that  with  birds  there  often  exists  a  close  rela- 
tion between  polygamy  and  the  develoj)ment  of  strongly- 
marked  sexual  differences.  On  asking  Mr.  Bartlett,  at 
the  Zoological  Gardens,  who  has  had  such  large  experi- 
ence with  birds,  whether  the  male  tragopan  (one  of  the 
Gallinaceae)  was  polygamous,  I  was  struck  by  his  answer- 
ing, "  I  do  not  know,  but  should  think  so  from  his  S])lcn- 
did  colors." 

It  deserves  notice  that  the  instinct  of  pau-ing  with 
a  single  female  is  easily  lost  under  domestication.  The 
wild-duck  is  strictly  monogamous,  the  domestic  duck 
highly  polygamous.  The  Rev.  W.  D.  Fox  informs  me 
that  with  some  half-tamed  wild-ducks,  kept  on  a  large 
pond  in  his  neighborhood,  so  many  mallards  were  shot  by 
the  gamekeeper  that  only  one  was  left  for  every  seven  or 
eight  females ;  yet  unusually  large  broods  were  reared. 
The  guinea-fowl  is  strictly  monogamous ;  but  Mr.  Fox 
finds  that  his  birds  succeed  best  when  he  keeps  one  cock 
to  two  or  three  hens."     Canary-birds  pair  in  a  state  of  na- 

'  The  Rev.   E.  S.  Dixoa,   however,   speaks  positively  ('  Ornamental 


2G2  THE  PRINCIPLES  OF  [Part  II. 

turc,  but  the  breeders  in  England  Buccessfully  put  one 
male  tofour  or  five  females  ;  nevertheless  the  first  female, 
as  3Ir.  Fox  has  been  assured,  is  alone  treated  as  the  wife, 
she  and  her  young  ones  being  fed  by  him ;  the  others  are 
treated  as  concubines.  I  have  noticed  these  cases,  as  it 
renders  it  in  some  degi'ec  probable  tliat  monogamous  spe- 
cies, in  a  state  of  nature,  might  readily  become  either  tem- 
porarily or  permanently  polygamous. 

With  respect  to  reptiles  and  fishes,  too  little  is  known 
of  their  habits  to  enable  us  to  speak  of  their  marriage- 
arrangements.  The  stickle-back  (Gasterosteus),  however, 
is  said  to  be  a  jiolygamist ; "  and  the  male  during  the 
breeding-season  differs  conspicuously  from  the  female. 

To  sum  uj)  on  the  means  through  wliich,  as  fur  as  we 
can  judge,  sexual  selection  has  led  to  the  development  of 
secondary  sexual  characters.  It  has  been  shown  that  the 
largest  number  of  vigorous  offspring  will  be  reared  from 
the  pairing  of  the  strongest  and  best-armed  males,  which 
have  conquei'cd  other  males,  with  the  most  vigorous  and 
best-nourished  females,  which  are  the  first  to  breed  in  the 
spring.  Such  females,  if  they  select  the  more  attractive, 
and  at  the  same  time  vigorous,  males,  will  rear  a  larger 
number  of  offspring  than  the  retarded  females,  which 
must  pair  with  the  less  vigorous  and  less  attractive  males. 
So  it  Avill  be  if  the  more  vigorous  males  select  the  more 
attractive  and  at  the  same  time  healthy  and  vigorous  fe- 
males ;  and  this  will  especially  hold  good  if  the  male  de- 
fends the  female,  and  aids  in  providing  food  for  the  young. 
The  advantage  thus  gained  by  the  more  vigorous  pairs  in 
rearing  a  larger  number  of  offspring  has  apparently  suf- 
ficed to  render  sexual  selection  efficient.  But  a  large  pre- 
ponderance in  number  of  the  males  over  the  females  would 

Poultry,'  1848,  p.  VG)  about  the  eggs  of  the  gumea-fowl  being  infertile 
wlien  more  than  one  female  is  kept  with  the  same  male. 
'"  Noel  Humphrey.^,  '  River  Gardens,'  1857. 


Chap.  VIII.]  SEXUAL   SELECTION.  2G3 

be  still  more  efficient ;  whether  the  preponderance  was 
only  occasional  and  local,  or  permanent ;  whether  it  oc- 
curred at  birth,  or  subsequently  from  the  greater  destruc- 
tion of  the  females ;  or  whether  it  indirectly  followed  from 
the  practice  of  polygamy. 

The  Male  generally  more  modijied  than  the  Female. — 
Throughout  the  animal  kingdom,  when  the  sexes  differ 
from  each  other  in  external  appearance,  it  is  the  male 
which,  with  rare  exceptions,  has  been  chiefly  modified ; 
for  the  female  still  remains  more  like  the  young  of  her 
own  species,  and  more  like  the  other  members  of  the  same 
grou.p.  The  cause  of  this  seems  to  lie  in  the  males  of 
almost  all  animals  having  stronger  passions  than  the  fe- 
males. Hence  it  is  the  males  that  fight  together  and  sedu- 
lously display  their  charms  before  the  females  ;  and  those 
which  are  victorious  transmit  their  superiority  to  their 
male  offspring.  Why  the  males  do  not  transmit  their 
characters  to  both  sexes  will  hereafter  be  considered. 
That>-the  males  of  all  mammals  eagerly  pursue  the  females 
is  notorious  to  every  one.  So  it  is  with  birds  ;  but  many 
male  birds  do  not  so  much  pursue  the  female,  as  display 
their  plumage,  perform  strange  antics,  and  pour  forth 
their  song,  in  her  presence.  With  the  few  fish  which  have 
been  observed,  the  male  seems  much  more  eager  than  the 
female ;  and  so  it  is  with  alligators,  and  apparently  with 
Batrachians.  Throughout  the  enormous  class  of  insects, 
as  Kirby  remarks,"  "  the  law  is,  that  the  male  shall  seek 
the  female."  With  spiders  and  crustaceans,  as  I  hear 
from  two  great  authorities,  Mr.  Blackwall  and  Mr.  C. 
Spence  Bate,  the  males  are  more  active  and  more  erratic 
in  their  habits  than  the  females.  With  insects  and  crus- 
taceans, when  the  organs  of  sense  or  locomotion  are  pres- 

"  Kirby  and  Spence,  'Introduction  to  Entomology,' vol.   iii.    1826, 
p.  342. 


2Gi  THE  PRINCIPLES  OF  [Part  II. 

cut  ill  llic  one  sex  and  absent  in  the  other,  or  when,  as  is 
frequently  the  ease,  they  are  more  liighly  developed  in  the 
one  than  the  other,  it  is  almost  invariably  the  male,  as  far 
as  I  can  discover,  which  retains  such  organs,  or  has  them 
most  developed  ;  and  this  shows  that  the  male  is  the  more 
active  member  in  the  courtship  of  the  sexes." 

The  female,  on  the  other  hand,  with  the  rarest  excep- 
tion, is  less  eager  than  the  male.  As  the  illustrious  Hun- 
ter ''  long  ago  observed,  she  generally  "  requii'cs  to  be 
courted ; "  she  is  coy,  and  may  often  be  seen  endeavoring 
for  a  long  time  to  escape  from  the  male.  Every  one  who 
has  attended  to  the  habits  of  animals  will  be  able  to  call 
to  mind  instances  of  this  kind.  Judging  from  various 
facts,  hereafter  to  be  given,  and  from  the  results  which 
may  fairly  be  attributed  to  sexual  selection,  the  female, 
though  comparatively  passive,  generally  exerts  some 
choice  and  accepts  one  male  in  preference  to  others.  Or 
she  may  accept,  as  appearances  would  sometimes  lead  us 
to  believe,  not  the  male  which  is  the  most  attractive  to 
her,  but  the  one  which  is  the  least  distasteful.  The  ex- 
ertion of  some  choice  on  the  part  of  the  female  seems 
almost  as  general  a  law  as  the  eagerness  of  the  male. 

We  are  naturally  led  to  inquire  why  the  male  in  so 
many  and  such  widely-distinct  classes  has  been  rendered 
more  eager  than  the  female,  so  that  he  searches  for  her 
and  plays  the  more  active  part  in  courtship.     It  would  be 

'-  One  parasitic  Ilymenopterous  insect  (West wood,  '  Modem  Class, 
of  Insects,'  vol.  ii.  p.  160)  forms  an  exception  to  the  rule,  as  the  male 
has  rudimentary  wings,  and  never  quits  the  cell  in  which  it  is  bom, 
while  the  female  has  well-developed  wings.  Audouin  believes  that  the 
females  are  impregnated  by  the  males  which  are  born  in  the  same  cells 
with  tlicm ;  but  it  is  much  more  probable  that  the  females  visit  other 
cells,  and  thus  avoid  close  interbreeding.  We  shall  hereafter  meet  with 
a  few  exceptional  cases,  in  various  classes,  iu  which  the  female,  instead 
of  the  male,  is  the  seeker  and  wooer. 

'^  'Essays  and  Observations,'  edited  by  Owen,  vol.  i.  ISGl,  p.  101. 


Chap.  Till.]  SEXUAL   SELECTION.  265 

no  advantage  and  some  loss  of  power  if  both  sexes  were 
mutually  to  search  for  each  other ;  but  why  should  the 
male  almost  always  be  the  seeker?  With  plants,  the 
ovules  after  fertilization  have  to  be  nourished  for  a  time ; 
hence  the  pollen  is  necessarily  brought  to  the  female  or- 
gans— being  placed  on  the  stigma,  through  the  agency  of 
insects  or  of  the  wind,  or  by  the  spontaneous  movements 
of  the  stamens  ;  and  with  the  Algffi,  etc.,  by  the  locomo- 
tive power  of  the  antherozooids.  With  lowly-organized 
animals  permanently  affixed  to  the  same  spot  and  having 
their  sexes  separate,  the  male  element  is  invariably 
brought  to  the  female  ;  and  we  can  see  the  reason ;  for 
the  ova,  even  if  detached  before  being  fertilized  and  not 
i-equiring  subsequent  nourishment  or  protection,  would 
be,  from  their  larger  relative  size,  less  easily  transported 
than  the  male  element.  Hence  plants  "  and  many  of  the 
lower  animals  are,  in  this  respect,  analogous.  In  the  case 
of  animals  not  affixed  to  the  same  spot,  but  enclosed 
within  a  shell  Avith  no  power  of  protruding  any  part  of 
their  bodies,  and  in  the  case  of  animals  having  little 
power  of  locomotion,  the  males  must  trust  the  fertilizing 
element  to  the  risk  of  at  least  a  short  transit  through  the 
waters  of  the  sea.  It  would,  therefore,  be  a  great  advan- 
tage to  such  animals,  as  their  organization  became  per- 
fected, if  the  males  when  ready  to  emit  the  fertilizing  ele- 
ment, were  to  acquire  the  habit  of  approaching  the  female 
as  closely  as  possible.  The  males  of  various  lowly-organ- 
ized animals  having  thus  aboriginally  acquired  the  habit 
of  approaching  and  seeking  the  females,  the  same  habit 
would  naturally  be  transmitted  to  their  more  highly-de- 
veloped male  descendants  ;  and  in  order  that  they  should 

'•1  Frof.  Sachs  ('Lelirbuch  der  Botanik,'  1870,  s.  633)  in  speaking  of 
tlie  male  and  female  reproductive  cells,  remarks :  "  Verhalt  sich  die  eiue 
bei  der  Vereinigung  activ,  ....  die  andere  erscheint  bei  der  Vereini- 
gung  passiv." 


26G  THE   PRIXCIILES  OF  [Part  II. 

become  eflicient  seekers,  they  -would  have  to  be  endowed 
with  strong  passions.  The  acquirement  of  such  passions 
woidd  naturally  follow  from  the  more  eager  males  leaving 
a  larger  number  of  offspring  than  the  less  eager. 

The  great  eagerness  of  the  male  has  thus  indirectly 
led  to  the  much  more  frequent  development  of  secondary 
sexual  characters  in  the  male  than  in  the  female.  But 
the  development  of  such  characters  will  have  been  much 
aided,  if  the  conclusion  at  which  I  arrived,  after  studying 
domesticated  animals,  can  be  trusted,  namely,  that  the 
male  is  more  liable  to  vary  than  the  female.  1  am  aware 
how  difficult  it  is  to  verify  a  conclusion  of  this  kind. 
Some  slight  evidence,  however,  can  be  gained  by  compai*- 
ing  the  two  sexes  in  mankind,  as  man  has  been  more  care- 
fully observed  than  any  other  animal.  Duj-ing  the  Xo- 
vara  Expedition  "  a  vast  number  of  measurements  of  va- 
rious parts  of  the  body  in  different  races  were  made,  and 
the  men  were  found  in  almost  every  case  to  present  a 
greater  range  of  variation  than  the  women ;  but  I  shall 
have  to  recur  to  this  subject  in  a  future  chapter,  Mr.  J. 
Wood,"  who  has  carefully  attended  to  the  variation  of  the 
muscles  in  man,  puts  in  italics,  the  conclusion  that  "  the 
greatest  number  of  abnormalities  in  each  subject  is  found 
in  the  males."  lie  had  previously  remarked  that  "  alto- 
gether in  102  subjects  the  varieties  of  redundancy  were 
found  to  be  half  as  many  again  as  in  females,  contrasting 
widely  with  the  greater  frequency  of  deliciency  in  females 
before  described."     Prof.   Macalister  likewise  remarks " 

15'Rcise  der  Novaia :  Anthropolog.  Theil,'  1867,  s.  210-200.  The 
results  were  calculated  by  Dr.  Weisbach  from  measurements  made  by 
Drs.  K.  Scherzer  and  Sehwarz.  On  the  greater  variability  of  the  males 
of  domesticated  animals,  see  my  '  Vai-iation  of  Animals  and  Plants  under 
Domestication,'  vol.  ii.  1808,  p.  V."". 

'^  'Proceedings  Royal  Soc.'  vol.  xvi.  July,  1808,  pp.  510,  524. 

''  'Proc.  Royal  Irish  Academy,'  vol.  x.  1808,  p.  12o. 


Chap.  VIII.]  SEXUAL   SELECTION.  267 

that  variations  in  the  muscles  "  are  probably  more  com- 
mon in  males  than  females."  Certain  muscles  which  are 
not  normally  present  in  mankind  are  also  more  frequently 
developed  in  the  male  than  in  the  female  sex,  although 
exceptions  to  this  rule  are  said  to  occur.  Dr.  Burt  Wild- 
er'* has  tabulated  the  cases  of  152  individuals  with  su- 
pernumerary digits,  of  which  86  were  males,  and  39,  or  less 
than  half,  females ;  the  remaining  27  being  of  unknown 
sex.  It  should  not,  however,  be  overlooked  that  women 
would  more  frequently  endeavor  to  conceal  a  deformity 
of  this  kind  than  men.  Whether  the  large  proportional 
number  of  deaths  of  the  male  offspring  of  man  and  appar- 
ently of  sheep,  compared  with  the  female  offspring,  be- 
fore, during,  and  shortly  after  birth  (see  supplement),  has 
any  relation  to  a  stronger  tendency  in  the  organs  of  the 
male  to  vary  and  thus  to  become  abnormal  in  structure  or 
function,  I  will  not  pretend  to  conjecture. 

In  various  classes  of  animals  a  few  exceptional  cases 
occur,  in  wliich  the  female  instead  of  the  male  has  ac- 
quired well-pronounced  secondary  sexual  characters,  such 
as  brighter  colors,  greater  size,  strength,  or  pugnacity. 
With  birds,  as  we  shall  hereafter  see,  there  has  sometimes 
been  a  complete  transposition  of  the  ordinary  characters 
proper  to  each  sex ;  the  females  having  become  the  more 
eager  in  courtship,  the  males  remaining  comparatively 
passive,  but  apparently  selecting,  as  we  may  infer  from 
the  results,  the  more  attractive  females.  Certain  female 
birds  have  thus  been  rendered  more  highly  colored  or 
otherwise  ornamented,  as  well  as  more  powerful  and  pug- 
nacious, than  the  males,  these  characters  being  transmit- 
ted to  the  female  offspring  alone. 

It  may  be  suggested  that  in  some  cases  a  double  pro- 
cess of  selection  has  been  carried  on ;  the  males  having 

'^  'Massachusetts  Medical  Soc'  vol.  ii.  No.  3,  18G8,  p.  9. 


268  THE  rmXCIPLES  OF  [Part  n. 

selected  the  more  attractive  females,  and  the  latter  the 
more  attractive  males.  This  process,  however,  though  it 
might  lead  to  the  modification  of  both  sexes,  would  not 
make  the  one  sex  different  from  the  other,  unless  indeed 
their  taste  for  the  beautiful  differed ;  but  this  is  a  suppo- 
sition too  improbable  iu  the  case  of  any  animal,  excepting 
man,  to  be  worth  considering.  There  are,  however,  many- 
animals,  in  which  the  sexes  resemble  each  other,  both 
being  furnislied  with  the  same  ornaments,  which  analogy 
would  lead  lis  to  attribute  to  the  agency  of  sexual  selec- 
tion. In  such  cases  it  may  be  suggested  with  more 
plausibility,  that  there  has  been  a  double  or  mutual  pro- 
cess of  sexual  selection ;  the  more  vigorous  and  precocious 
females  having  selected  the  more  attractive  and  vigorous 
males,  the  latter  having  rejected  all  except  the  more  at- 
tractive females.  But,  from  what  we  know  of  the  habits 
of  animals,  this  view  is  hardly  probable,  the  male  being 
generally  eager  to  pair  with  any  female.  It  is  more 
probable  that  the  ornaments  common  to  both  sexes  were 
acquired  by  one  sex,  generally  the  male,  and  then  trans- 
mitted to  the  offspring  of  both  sexes.  If,  indeed,  during 
a  lengthened  period  the  males  of  any  sj)ecies  were  greatly 
to  exceed  the  females  in  number,  and  then  during  another 
lengthened  period  under  different  conditions  the  reverse 
were  to  occur,  a  double,  but  not  simultaneous,  process  of 
sexual  selection  might  easily  be  carried  on,  by  which  the 
two  sexes  might  be  rendered  widely  diflferent. 

We  shall  hereafter  see  that  many  animals  exist,  of 
which  neither  sex  is  brilliantly  colored  or  provided  with 
special  ornaments,  and  yet  the  members  of  both  sexes  or 
of  one  alone  have  probably  been  modified  through  sexual 
selection.  The  absence  of  bright  tints  or  other  ornaments 
may  be  the  result  of  variations  of  the  right  kind  never 
having  occuiTcd,  or  of  the  animals  themselves  preferring 
simple  colors,  such   as   plain   black   or  white.     Obscure 


Ciup.  VIII.]  SEXUAL  SELECTION.  269 

colors  have  often  been  acquired  through  natural  selection 
for  the  sake  of  protection,  and  the  acquirement  through 
sexual  selection  of  conspicuous  colors,  may  have  hcen 
checked  from  the  danger  thus  incurred.  But  in  other 
cases  the  males  have  probably  struggled  together  during 
long  ages,  through  brute  force,  or  by  the  display  of  their 
charms,  or  by  both  means  combined,  and  yet  no  effect 
"svill  have  been  produced  iinless  a  larger  number  of  off- 
spring were  left  by  the  more  successful  males  to  inherit 
their  superiority,  than  by  the  less  successful  males ;  and 
this,  as  previously  shown,  depends  on  various  complex 
contingencies. 

Sexual  selection  acts  in  a  less  rigorous  maimer  than 
natural  selection.  The  latter  produces  its  effects  by  the 
life  or  death  at  all  ages  of  the  more  or  less  successful 
individuals.  Death,  indeed,  not  rarely  ensues  from  the 
conflicts  of  rival  males.  But  generally  the  less  successful 
male  merely  fails  to  obtain  a  female,  or  obtains  later  in 
the  season  a  retarded  and  less  vigorous  female,  or,  if  polyg- 
amous, obtains  fewer  females ;  so  that  they  leave  fewer, 
or  less  vigorous,  or  no  offspring.  In  regard  to  structures 
acquired  through  ordinary  or  natural  selection,  there  is  in 
most  cases,  as  long  as  the  conditions  of  life  remain  the 
same,  a  limit  to  the  amount  of  advantageous  modification 
in  relation  to  certain  special  ends  ;  but  in  regard  to  struct- 
ures adapted  to  make  one  male  victorious  over  another, 
either  in  fighting  or  in  charming  the  female,  there  is  no 
definite  limit  to  the  amount  of  advantageous  modification ; 
so  that  as  long  as  the  proper  variations  arise  the  work  of 
sexual  selection  will  go  on.  This  circumstance  may  part- 
ly account  for  the  frequent  and  extraordinary  amount 
of  variability  presented  by  secondary  sexual  characters. 
Nevertheless,  natural  selection  will  determine  that  charac- 
ters of  this  kind  shall  not  be  acquired  by  the  victorious 
males,  which  would   be  injurious  to  them  in  any  high 


270  THE   PRINCIPLES  OF  [Pakt  II. 

degree,  either  by  expending  too  much  of  their  vital 
powers,  or  by  exposing  them  to  any  great  danger.  The 
development,  however,  of  ccrtjiin  structures — of  the  horns, 
for  instance,  in  certain  stags — has  been  carried  to  a  won- 
derful extreme;  and  in  some  instances  to  an  extreme 
which,  as  far  us  the  general  conditions  of  life  are  con- 
cerned, must  be  sliglitly  injurious  to  the  male.  From  this 
fact  we  learn  that  the  advantages  which  favored  males 
have  derived  from  conquering  other  males  in  battle  or 
courtship,  and  thus  leaving  a  numerous  progeny,  have 
been  in  the  long-run  greater  than  those  derived  from 
rather  more  perfect  adaptation  to  the  external  conditions 
of  life.  We  shall  further  see,  and  this  could  never  have 
been  anticipated,  that  the  power  to  charm  the  female  has 
been  in  some  few  instances  more  important  than  the 
power  to  conquer  other  males  in  battle. 

LAWS  OF  INHEPvITANCE. 

In  order  to  understand  how  sexual  selection  has  acted, 
and  in  the  course  of  ages  has  produced  conspicuous  re- 
sults with  many  animals  of  many  classes,  it  is  necessary 
to  bear  in  mind  the  laws  of  inheritance,  as  far  as  they  are 
known.  Two  distinct  elements  are  included  under  the 
term  "inheritance,"  namely,  the  transmission  and  the 
development  of  characters ;  but  as  these  generally  go  to- 
gether, the  distinction  is  often  overlooked.  We  see  this 
distinction  in  those  characters  which  are  transmitted 
through  the  early  years  of  life,  but  are  developed  only  at 
maturity  or  during  old  age.  We  see  the  same  distinction 
more  clearly  with  secondary  sexual  characters,  for  these 
are  transmitted  through  both  sexes,  though  developed  in 
one  alone.  That  they  arc  present  in  both  sexes,  is  mani- 
fest Avhen  two  species,  having  strongly-marked  sexual 
characters,  are  crossed,  for  each  transmits  the  characters 


Chap.  VIIL]  SEXUAL   SELECTION.  2?1 

proper  to  its  own  male  and  female  sex  to  the  hybrid  off- 
spring of  both  sexes.  The  same  fact  is  likewise  manifest, 
when  characters  proper  to  the  male  are  occasionally  de- 
veloped in  the  female  Avhen  she  grows  old  or  becomes 
diseased;  and  so  conversely  with  the  male.  Again,  char- 
acters occasionally  appear,  as  if  transferred  from  the  male 
to  the  female,  as  when,  in  certain  breeds  of  the  fowl,  spiirs 
regularly  appear  in  the  young  and  healthy  females ;  but 
in  truth  they  arc  simply  developed  in  the  female ;  for  in 
every  breed  each  detail  in  the  structure  of  the  spur  is 
transmitted  through  the  female  to  her  male  olFspring.  In 
all  cases  of  reversion,  characters  are  transmitted  through 
two,  three,  or  many  generations,  and  are  then  under  cer- 
tain unknown  favorable  conditions  developed.  This  im- 
portant distinction  between  transmission  and  development 
will  be  easiest  kept  in  mind  by  the  aid  of  the  hypothesis 
of  pangenesis,  whether  or  not  it  be  accepted  as  true.  Ac- 
cording to  this  hypothesis,  every  unit  or  cell  of  the  body 
throws  off  gemmules  or  undeveloped  atoms,  which  are 
transmitted  to  the  offspring  of  both  sexes,  and  are  multi- 
plied by  self-division.  They  may  remain  undeveloped 
durmg  the  early  years  of  life  or  during  successive  genera- 
tions ;  their  development  into  units  or  cells,  like  those 
from  which  they  were  derived,  depending  on  their  affinity 
for,  and  union  with,  other  units  or  cells  previously  devel- 
oped in  the  due  order  of  growtli. 

Inheritance  at  Corresponding  Periods  of  Life. — This 
tendency  is  well  established.  If  a  new  character  appears 
in  an  animal  while  young,  whether  it  endures  throughout 
life  or  lasts  only  for  a  time,  it  will  reappear,  as  a  general 
rule,  at  the  same  age  and  in  the  same  manner  in  the  off- 
spring. If,  on  the  other  hand,  a  new  character  appears  at 
maturity,  or  even  during  old  age,  it  tends  to  reappear  in 
the  offspring  at  the  same  advanced  age.    When  deviations 


272  THE   rRINCIPLES  OF  [Part  IL 

from  tliis  rule  occur,  the  transmitted  characters  much  of- 
tener  appear  before  than  after  the  corresponding  age.  As 
I  have  discussed  this  subject  at  sufficient  length  in  another 
•work,'"  I  will  here  merely  give  two  or  three  instances,  for 
the  sake  of  recalling  the  subject  to  the  reader's  mind.  In 
several  breeds  of  the  Fowl,  the  chickens  Avhile  covered 
vrith  down,  in  their  first  true  plumage,  and  in  their  adult 
plumage,  differ  greatly  from  each  other,  as  well  as  from 
their  common  parent-form,  the  Gallus  hankiva  ;  and  these 
characters  are  faithfully  transmitted  by  each  breed  to  their 
offspring  at  the  corresponding  period  of  life.  For  instance, 
the  chickens  of  spangled  Hamburgs,  while  covered  with 
down,  have  a  few  dark  spots  on  the  head  and  rump,  but 
are  not  longitudinally  striped,  as  in  many  other  breeds ;  in 
their  first  true  plumage,  "they  are  beautifully  pencilled." 
that  is,  each  feather  is  transversely  marked  by  numerous 
dark  bars  ;  but  in  their  second  plumage  the  feathers  all 
become  spangled  or  tipped  with  a  dark  round  spot.'" 
Hence  in  this  breed  variations  have  occurred  and  have 
been  transmitted  at  three  distinct  periods  of  life.  The 
Pigeon  offers  a  more  remarkable  case,  because  the  abori- 
ginal parent-species  does  not  ixndergo  with  advancing  age 
any  change  of  plumage,  excepting  that  at  maturity  the 
breast  becomes  more  iridescent ;  yet  there  are  breeds  which 
do  not  acquire  their  characteristic  colors  until  they  have 
moulted  two,  three,  or  four  times ;  and  these  modifications 
of  plumage  are  regularly  transmitted. 

'^  '  The  Variation  of  Animals  and  Plants  under  DomesticatioD,'  vol  ii. 
18G8,  p.  75.  In  the  last  chapter  but  one,  the  provisional  hypothesis  of 
pangenesis,  above  alluded  to,  is  fully  explained. 

-"  These  facts  are  given  on  the  high  authority  of  a  great  breeder,  Mr. 
Tccbay,  in  Tegctmeier's  'Poultry  Book,'  18G8,  p.  158.  On  the  characters 
of  chickens  of  different  breeds,  and  on  the  breeds  of  the  pigeon,  alluded 
to  in  the  above  paragraph,  sec  '  Yariation  of  Animals,'  etc.,  vol.  i.  pp.  160, 
249  ;  vol.  ii.  p.  77. 


Chap.  YIII.]  SEXUAL   SELECTION.  273 

Inheritancs  at  Corresponding  Seasons  of  the  Year. — 
With  animals  in  a  state  of  nature  innumerable  instances 
occur  of  characters  periodically  appearing  at  different  sea- 
sons. We  see  this  with  the  horns  of  the  stag,  and  with 
the  fur  of  arctic  animals  which  becomes  thick  and  white 
daring  the  winter.  Numerous  birds  acquire  bright  colors 
and  other  decollations  during  the  breeding-season  alone.  I 
can  throw  but  little  light  on  this  form  of  inheritance  from 
facts  observed  under  domestication.  Pallas  states "'  that,  in 
Siberia,  domestic  cattle  and  horses  periodically  become 
lighter-colored  during  the  winter ;  and  I  have  observed  a 
similar  marked  change  of  color  in  certain  ponies  in  Eng- 
land. Although  I  do  not  know  that  this  tendency  to  as- 
sume a  differently-colored  coat  during  different  seasons  of 
the  year  is  transmitted,  yet  it  probably  is  so,  as  all  shades 
of  color  are  strongly  inherited  by  the  horse.  Nor  is  this 
form  of  inheritance,  as  limited  by  season,  more  remarkable 
than  inheritance  as  limited  by  age  or  sex. 

Inheritance  as  limited  hy  Sex. — The  equal  transmis- 
sion of  characters  to  both  sexes  is  the  commonest  form  of 
inheritance,  at  least  with  those  animals  which  do  not  pre- 
sent strongly-marked  sexual  differences,  and  indeed  with 
many  of  these.  But  characters  are  not  rarely  transferred 
exclusively  to  that  sex,  in  which  they  first  appeared. 
Ample  evidence  on  this  head  has  been  advanced  in  my 
work  on  Variation  imder  Domestication;  but  a  few  in- 
stances may  here  be  given.  There  are  breeds  of  the  sheep 
and  goat,  in  which  the  horns  of  the  male  differ  greatly  in 
shape  from  those  of  the  female ;  and  these  differences,  ac- 
quired under  domestication,  are  regularly  transmitted  to 

^'  '  Nova;  species  Quadrupedum  e  Glirium  ordine,'  1778,  p.  7.  Ou  the 
transmission  of  color  by  the  horse,  see  'Variation  of  Animals,  etc.,  under 
Domestication,'  vol.  i.  p.  21.  Also  vol.  ii.  p.  71,  for  a  general  discussion 
on  Inheritance  as  limited  by  Sex. 


274  THE   PRINCIPLES  OF  [Part  II. 

the  same  sex.  With  tortoise-shell  cats  the  females  alone, 
as  a  general  rule,  ai*c  thus  colored,  the  males  being  rusty- 
red.  With  most  breeds  of  the  fowl,  the  characters  proper 
to  each  sex  are  transmitted  to  the  same  sex  alone.  So 
general  is  this  form  of  transmission  that  it  is  an  anomaly 
when  we  see  in  certain  breeds  variations  transmitted  equal- 
ly to  both  sexes.  There  are  also  certain  sub-breeds  of  the 
fowl  in  which  the  males  can  hardly  be  distinguished  from 
each  other,  while  the  females  difier  considerably  in  color. 
With  the  pigeon  tlie  sexes  of  the  parent-species  do  not 
difier  in  any  external  character;  nevertheless  in  certain 
domesticated  breeds  the  male  is  differently  colored  from 
the  female."  The  wattle  in  the  English  Carrier-pigeon 
and  the  crop  in  the  Pouter  are  more  highly  developed  in 
tlie  male  than  in  the  female ;  and  altliough  these  chax'acters 
have  been  gained  through  long-continued  selection  by  man, 
the  difFerence  between  the  two  sexes  is  wholly  due  to  the 
form  of  inheritance  which  has  prevailed ;  for  it  has  arisen, 
not  from,  but  rather  in  opposition  to,  tlie  Avishes  of  the 
breedei". 

Most  of  our  domestic  races  have  been  formed  by  the 
accumulation  of  many  slight  variations ;  and  as  some  of 
the  successive  steps  have  been  transmitted  to  one  sex 
alone,  and  some  to  both  sexes,  we  find  in  the  difierent 
breeds  of  the  same  species  all  gradations  between  great 
sexual  dissimilarity  and  complete  similarity.  Instances 
have  already  been  given  with  the  breeds  of  the  fowl  and 
pigeon ;  and  under  Nature  analogous  cases  are  of  fre- 
quent occurrence.  With  animals  under  domestication,  but 
whether  under  Nature  I  will  not  venture  to  say,  one  sex 
may  lose  characters  proper  to  it,  and  may  thus  come  to 
resemble  to  a  certain  extent  the  opposite  sex ;  for  in- 
stance, the  males  of  some  breeds  of  the  fowl  have  lost 

"^^  Dr.  Chapuis,  '  Lc  Pigeon  Voyageur  Beige,'  1865,  p.  87.     Boitard 
ct  Corbie,  '  Les  Pigeons  dc  Voliore,'  etc.,  1824,  p.  173. 


Chap.  VIII.]  SEXUAL   SELECTION.  2V5 

their  masculine  plumes  and  hackles.  On  the  other  hand, 
the  diiferences  between  the  sexes  may  be  increased  under 
domestication,  as  with  merino  sheep,  in  which  the  ewes 
have  lost  their  horns.  Again,  characters  proper  to  one 
sex  may  suddenly  ajDpear  in  the  other  sex ;  as  with  those 
sub-breeds  of  the  fowl  in  which  the  hens  while  young  ac- 
quire spurs ;  or,  as  in  certain  Polish  sub-breeds,  in  which 
the  females,  as  there  is  reason  to  believe,  originally  ac- 
quired a  crest,  and  subsequently  transferred  it  to  the 
males.  All  these  cases  are  intelligible  on  the  hypothesis 
of  pangenesis  ;  for  they  depend  on  the  gemmules  of  certain 
units  of  the  body,  although  .present  in  both  sexes,  becoming 
through  the  influence  of  domestication  dormant  in  the  one 
sex  ;  or,  if  naturally  dormant,  becoming  developed. 

There  is  one  difficult  question  which  it  will  be  conven- 
ient to  defer  to  a  future  chapter ;  namely,  whether  a  char- 
acter, at  first  developed  in  both  sexes,  can  be  rendered 
through  selection  limited  in  its  development  to  one  sex 
alone.  If,  for  instance,  a  breeder  observed  that  some  of 
his  pigeons  (in  which  species  characters  are  usually  trans- 
ferred in  an  equal  degree  to  both  sexes)  varied  into  pale 
blue ;  could  he  by  long-continued  selection  make  a  breed, 
in  which  the  males  alone  should  be  of  this  tint  while  the 
females  remained  unchanged  ?  I  will  here  only  say  that 
this,  though  perhaps  not  impossible,  would  be  extremely 
difficult ;  for  the  natural  result  of  breeding  from  the  pale- 
blue  males  would  be  to  change  his  whole  stock,  including 
both  sexes,  into  this  tint.  If,  hov,^ever,  variations  of  the 
desired  tint  appeared,  which  were  from  the  first  limited 
in  their  develoi)ment  to  the  male  sex,  there  would  not  be 
the  least  difficulty  in  making  a  breed  characterized  by  the 
two  sexes  being  of  a  dififerent  color,  as  indeed  has  been 
eftected  with  a  Belgian  breed,  in  which  the  males  alone 
are  streaked  with  black.  In  a  similar  manner,  if  any  vari- 
ation appeared  in  a  female   pigeon,  which  was  from  the 


276  THE   PRINCIPLES  OF  [Part  II. 

first  sexually  limited  in  its  development,  it  would  be  easy 
to  make  a  breed  with  the  females  alone  thus  character- 
ized ;  but  if  tlic  variation  was  not  thus  originally  limited, 
the  process  would  be  extremely  difficult,  perhaps  impos- 
sible. 

Oa  the  Relation  between  the  period  of  Development  of 
a  Character  and  its  transtnission  to  one  sex  or  to  both 
sexes. — Why  certain  characters  should  be  inherited  by 
both  sexes,  and  other  characters  by  one  sex  alone,  namely, 
by  that  sex  in  which  the  character  first  appeared,  is  in 
most  cases  quite  unknown.  We  cannot  even  conjecture 
why  with  certain  sub-breeds  of  the  pigeon,  black  striae, 
though  transmitted  through  the  female,  should  be  dc- 
velo})ed  in  the  male  alone,  while  every  other  character  is 
equally  transferred  to  both  sexes.  Why,  again,  with  cats, 
tlie  tortoise-shell  color  should,  with  rare  exceptions,  be 
developed  in  the  female  alone.  The  very  same  characters, 
such  as  deficient  or  supernumerary  digits,  color-blindness, 
etc.,  may  with  mankind  be  inherited  by  the  males  alone 
of  one  family,  and  in  another  family  by  the  females  alone, 
tliough  in  both  cases  transmitted  through  the  opposite  as 
well  as  the  same  sex."  Although  Ave  are  thus  ignorant, 
two  rules  often  hold  good,  namely,  that  variations  which 
first  appear  in  either  sex  at  a  late  period  of  life,  tend  to 
be  developed  in  the  same  sex  alone ;  while  variations 
which  first  appear  early  in  life  in  cither  sex  tend  to  be 
develoj^ed  in  both  sexes.  I  am,  however,  far  from  sup- 
posing that  this  is  the  sole  determining  cause.  As  I  have 
not  elsewhere  discussed  this  subject,  and  as  it  has  an  im- 
portant bearing  on  sexual  selection,  I  must  here  enter 
into  lengthy  and  somewhat  intricate  details. 

It  is  in  itself  probable  that  any  character  a])pcaring  at 

'^  References  are  given  in  my  '  Variation  of  Animals  under  Domo3ti- 
cation,'  vol.  ii.  p.  12. 


CuAP.  VIIL]  SEXUAL  SELECTION.  211 

an  early  age  would  tend  to  be  inherited  equally  by  both 
sexes,  for  the  sexes  do  not  differ  much  in  constitution,  be- 
fore the  power  of  reproduction  is  gained.  On  the  other 
hand,  after  this  power  has  been  gained  and  the  sexes  have 
come  to  differ  in  constitution,  the  gemnniles  (if  I  may 
again  use  the  language  of  pangenesis)  which  are  cast  off 
from  each  varying  part  in  the  one  sex  would  be  much 
more  likely  to  possess  the  proper  affinities  for  uniting 
with  the  tissues  of  the  same  sex,  and  thus  becoming  de- 
veloped, than  with,  those  of  the  opposite  sex. 

I  was  first  led  to  infer  that  a  relation  of  this  kind  ex- 
ists, from  the  fact  that  whenever  and  in  whatever  manner 
tlie  adult  male  has  come  to  differ  from  the  adult  female, 
he  differs  in  the  same  manner  from  the  young  of  both 
sexes.  The  generality  of  this  fact  is  quite  remarkable  :  it 
holds  good  with  almost  all  mammals,  birds,  amphibians, 
and  fishes  ;  also  with  many  crustaceans,  sj)iders,  and  some 
few  insects,  namely,  certain  orthoptera  and  libellula?.  In 
all  these  cases  the  variations,  through  the  accumulation  of 
which  the  male  acquired  his  proper  masculine  characters, 
must  have  occurred  at  a  somewhat  late  period  of  life; 
otherwise  the  young  males  would  have  been  similarly 
characterized ;  and  conformably  with  our  rule,  they  are 
transmitted  to  and  developed  in  the  adult  males  alone. 
When,  on  the  other  hand,  the  adult  male  closely  resem- 
bles the  young  of  both  sexes  (these,  with  rare  exceptions, 
being  alike),  he  generally  resembles  the  adult  female; 
and  in  most  of  these  cases  the  variations  through  which 
the  young  and  old  acquired  their  present  characters,  prob- 
ably occurred  in  conformity  with  our  rule  during  y  outh. 
But  there  is  here  room  for  doubt,  as  characters  are  some- 
times transferred  to  the  offspring  at  an  earlier  age  than 
that  at  which  they  first  appeared  in  the  parents,  so  that 
the  parents  may  have  varied  when  adult,  and  have  trans- 
ferred  their   characters   to   their   offspring  while  young. 


278  THE   PRIXCIPLES   OF  [Paut  II. 

There  are,  moreover,  many  animals,  in  -svliicli  the  two 
sexes  closely  resemble  each  other,  and  yet  both  differ 
from  their  young ;  and  here  the  characters  of  the  adults 
must  have  been  acquired  late  in  life ;  nevertheless,  these 
characters  in  apparent  contradiction  to  our  rule,  are  trans- 
ferred to  both  sexes.  "VYe  must  not,  however,  overlook 
the  possibility  or  even  probability  of  successive  variations 
of  the  same  nature  sometimes  occurring,  under  exposure 
to  similar  conditions,  simultaneously  in  both  sexes  at  a 
rather  late  period  of  life ;  and  in  this  case  the  variations 
would  be  transferred  to  the  offspring  of  both  sexes  at  a 
corresjionding  late  age  ;  and  there  would  be  no  real  con- 
tradiction to  our  rule  of  the  variations  which  occur  late  in 
life  being  transferred  exclusively  to  the  sex  in  Avhich  they 
first  appeared.  This  latter  rule  seems  to  hold  true  more 
generally  than  the  second  rule,  namely,  that  variations 
which  occur  in  either  sex  early  in  life  tend  to  be  trans- 
ferred to  both  sexes.  As  it  was  obviously  impossible  even 
to  estimate  in  how  large  a  number  of  cases  throughout  the 
animal  kingdom  these  two  propositions  hold  good,  it  oc- 
curred to  me  to  investigate  some  striking  or  crucial  in- 
stances, and  to  rely  on  the  result. 

An  excellent  case  for  investigation  is  afforded  by  the 
Deer  Family.  In  all  the  sjitccies,  excepting  one,  the  horns 
are  developed  in  the  male  alone,  though  certainly  trans- 
mitted through  the  female,  and  capable  of  occasional  ab- 
normal development  in  her.  In  the  reindeei",  on  the  other 
hand,  the  female  is  provided  Avith  horns  ;  so  that  in  this 
species,  the  horns  ought,  according  to  our  rule,  to  appear 
early  in  life,  long  before  the  two  sexes  had  arrived  at 
maturity  and  had  come  to  differ  much  in  constitution.  In 
all  the  other  species  of  deer  the  horns  ought  to  appear 
later  in  life,  leading  to  their  development  in  that  sex 
alone,  in  which  they  first  appeared  in  the  progenitor  of 
the  whole  Family.  -  ISTow,  in  seven  species,  belonging  to 


Chap.  VIII.]  SEXUAL   SELECTION.  279 

distinct  sections  of  the  family  and  inhabiting  different 
regions,  in  which  the  stags  alone  bear  horns,  I  find  that 
the  horns  first  appear  at  periods  varying  from  nine  months 
after  birth  in  the  roebuck  to  ten  or  twelve  more  months 
in  the  stags  of  the  six  other  larger  species.^*  But  with 
the  reindeer  the  case  is  widely  different,  for  as  I  hear  from 
Prof.  Nilsson,  who  kindly  made  special  inquiries  for  me 
in  Lapland,  the  horns  appear  in  the  young  animals  within 
four  or  five  weeks  after  birth,  and  at  the  same  time  in 
both  sexes.  So  that  here  we  have  a  structure,  developed 
at  a  most  unusually  early  age  in  one  species  of  the  family, 
and  common  to  both  sexes  in  this  one  species. 

In  several  kinds  of  antelopes  the  males  alone  are  pro- 
vided with  horns,  while  in  the  greater  number  both  sexes 
have  horns.  With  respect  to  the  period  of  development, 
Mr.  Blyth  informs  me  that  there  lived  at  one  time  in  the 
Zoological  Gardens  a  young  koodoo  (Ant.  strepsiceros), 
in  which  species  the  males  alone  are  horned,  and  the 
young  of  a  closely-allied  species,  viz.,  the  eland  {Ant. 
oreas),  in  which  both  sexes  are  horned.  Now  in  strict 
conformity  with  our  rule,  in  the  young  male  koodoo,  al- 
though arrived  at  the  age  of  ten  months,  the  horns  were 
remarkably  small  considering  the  size  ultimately  attained 
by  them :  while  in  the  young  male  eland,  although  only 
three  months  old,  the  horns  were  already  very  much  larger 
than  in  the  koodoo.     It  is  also  worth  notice  that  in  the 

^^  I  am  much  obliged  to  Mr.  Cupples  foi'  having  made  inquiries  for 
me  in  regard  to  the  Roebuck  and  Eed  Deer  of  Scotland  from  Mr.  Rob- 
ertson, the  experienced  head-forester  to  the  Marquis  of  Breadalbane.  In 
regard  to  Fallow-deer,  I  am  obliged  to  Mr.  Eyton  and  others  for  informa- 
tion. For  the  Cerj^ws  a?ce5  of  North  America,  see  '  Land  and  Water,'  1868, 
pp.  221  and  234  ;  and  for  the  C.  Virginianus  and  strongyloccros  of  the 
same  continent,  see  J.  D.  Caton,  in  '  Ottawa  Acad,  of  Nat.  Sc'  1868,  p. 
13.  For  Cervus  IJldl  q{  Pegu,  sae  Lieut.  Beavan,  'Proc.  Zoolog.  Soc' 
ISGY,  p.  '762. 


280  TUE   rilLVCirLES   OF  [I\u'.t  II. 

prong-liornccl  antelope,"  in  which  species  the  horns,  though 
present  in  both  sexes,  are  almost  rudimentary  in  the 
female,  they  do  not  appear  until  about  five  or  six  months 
after  birth.  With  sheep,  goats,  and  cattle,  in  which  the 
horns  are  well  developed  in  both  sexes,  though  not  quite 
equal  in  size,  they  can  be  felt,  or  even  seen,  at  birth,  or 
soon  afterward.'*  Our  rule,  however,  fails  in  regard  to 
some  bi'eeds  of  sheep,  for  instance,  merinos,  in  which  the 
rams  alone  are  horned;  for  I  cannot  find  on  inquiry,'^  that 
the  horns  are  developed  later  in  life  in  this  breed  than  in 
ordinary  sheep  in  which  both  sexes  are  horned.  But  with 
domesticated  sheep  the  presence  or  absence  of  horns  is 
not  a  firmly-fixed  character ;  a  certain  proportion  of  the 
merino  ewes  bearing  small  horns,  and  some  of  the  rams 
being  hornless ;  while  with  ordinary  sheep  hornless  ewes 
are  occasionally  produced. 

In  most  of  the  species  of  the  splendid  family  of  the 
Pheasants,  the  males  differ  conspicuously  from  the  females, 
and  they  acquire  their  ornaments  at  a  rather  late  period  of 
life.  The  eared  pheasant  {Crosso2:)tllo)i  awifum),  how- 
ever, offers  a  remarkable  exception,  for  both  sexes  jiossess 

""•  Antilocapra  Americana.  Owen,  'Anatomy  of  Vertebrates,'  vol. 
iii.  p.  627. 

*^  I  have  been  assured  that  the  horns  of  the  sheep  in  North  Wales 
can  always  be  felt,  and  are  sometimes  even  an  inch  in  length,  at  birth. 
With  cattle  Youatt  says  ('  Cattle,'  1834,  p.  2*77)  that  the  prominence  of 
the  frontal  bone  penetrates  the  cutis  at  birth,  and  that  the  homy  matter 
is  soon  formed  over  it. 

*■'  I  am  greatly  indebted  to  Prof.  Victor  Carus  for  having  made  in- 
quiries for  me,  from  the  highest  authorities,  with  respect  to  the  merino 
sheep  of  Saxony.  On  the  Guinea  coast  of  Africa  there  is  a  breed  of 
sheep  in  which,  as  with  merinos,  the  rams  alone  bear  horns ;  and  Mr. 
Winwood  Reade  informs  me  that  in  the  one  case  observed,  a  young  ram 
bom  on  February  10th  first  showed  horns  on  March  Cth,  so  that  in  this 
riistance  the  development  of  the  horns  occurred  at  a  later  period  of  life, 
conformably  with  our  rule,  than  in  the  Welsh  sheep,  in  which  both  sexes 
are  homed. 


Chap.  VIII.]  SEXUAL   SELECTION.  281 

the  fine  caudal  plumes,  the  large  ear-tufts  and  the  crimson 
velvet  about  the  head ;  and  I  find  on  inquiry  in  the  Zo- 
ological Gardens  that  all  these  characters,  in  accordance 
with  our  rule,  appear  very  early  in  life.  The  adult  male 
can,  however,  be  distinguished  from  the  adult  female  by 
one  character,  namely,  by  the  presence  of  spurs;  and 
conformably  with  our  rule,  these  do  not  begin  to  be  de- 
veloped, as  I  am  assured  by  Mr.  Bartlett,  before  the  age 
of  six  months,  and  even  at  this  age,  can  hardly  be  dis- 
tinguished in  the  two  sexes.^®  The  male  and  female 
Peacock  difier  conspicuously  from  each  other  in  almost 
every  part  of  then-  plumage,  except  in  the  elegant  head- 
crest,  which  is  common  to  both  sexes  ;  and  this  is  de- 
veloped very  early  in  life,  long  before  the  other  orna- 
ments which  are  confined  to  the  male.  The  wild-duck 
ofiers  an  analogous  case,  for  the  beautiful  green  speculum 
on  the  wings  is  common  to  both  sexes,  though  duller  and 
somewhat  smaller  in  the  female,  and  it  is  developed  early 
in  life,  while  the  curled  tail-feathers  and  other  ornaments 
peculiar  to  the  male  are  developed  later. '^^     Between  such 

2s  In  the  common  peacock  {Pavo  eristatus)  the  male  alone  possesses 
spurs,  while  both  sexes  of  the  Java  peacock  (P.  muticus)  offer  the  unu- 
sual case  of  being  furnished  with  spurs.  Hence  I  fully  expected  that  in 
the  latter  species  they  would  have  been  developed  earlier  in  life  than  in 
the  common  peacock ;  but  M.  Hegt,  of  Amsterdam,  informs  me  that, 
with  young  birds  of  the  previous  year,  belonging  to  both  species,  com- 
pared on  April  23,  1869,  there  was  no  difference  in  the  development  of 
the  spurs.  The  spurs,  however,  were  as  yet  represented  merely  by  slight 
knobs  or  elevations.  I  presume  that  I  should  have  been  informed  if 
any  difference  in  the  rate  of  development  had  subsequently  been  ob- 
served. 

-^  In  some  other  species  of  the  Duck  Family  the  speculum  iu  the  two 
sexes  diffei'S  in  a  greater  degree  ;  but  I  have  not  been  able  to  discover 
whether  its  full  development  occurs  later  in  life  in  the  males  of  such  spe- 
cies, than  in  the  male  of  the  common  duck,  as  ought  to  be  the  case  ac- 
cording to  our  jule.  With  the  alUed  Mcrgiis  cucullaius  we  have,  however, 
a  case  of  this  kind :  the  two  sexes  differ  conspicuously  in  general  plu- 
13 


282  THE  PRINCIPLES  OF  [Pakt  II. 

extreme  cases  of  close  sexual  resemblance  and  wide  dis- 
similarity, as  those  of  the  Crossoptilon  and  peacock,  many- 
intermediate  ones  could  be  given,  in  whicli  the  characters 
follow  in  their  order  of  development  our  two  rules. 

As  most  insects  emerge  from  their  pupal  state  in  a 
mature  condition,  it  is  doubtful  whether  the  period  of  de- 
velopment determines  the  transference  of  their  characters 
to  one  or  both  sexes.  But  we  do  not  know  that  the  col- 
ored scales,  for  instance,  in  two  species  of  butterflies,  in 
one  of  which  the  sexes  diiFcr  in  color,  while  in  the  other 
they  are  alike,  are  developed  at  the  same  relative  age  in 
the  cocoon.  Nor  do  we  know  whether  all  the  scales  are 
simultaneously  developed  on  the  wings  of  the  same  spe- 
cies of  butterfly,  in  which  certain  colored  marks  are  con- 
fined to  one  sex,  while  other  marks  are  common  to  both 
sexes.  A  difference  of  this  kind  in  the  period  of  develop- 
ment is  not  so  improbable  as  it  may  at  first  appear  ;  for, 
with  the  Orthoptera,  which  assume  their  adult  state,  not 
by  a  single  metamorphosis,  but  by  a  succession  of  moults, 
the  young  males  of  some  species  at  first  resemble  the  fe- 
males, and  acquire  their  distinctive  masciilino  characters 
only  during  a  later  moult.  Strictly  analogous  cases  occur 
during  the  successive  moults  of  certain  male  crustaceans. 

We  have  as  yet  only  considered  the  transference  of 
characters,  relatively  to  their  period  of  development,  Avith 
species  in  a  natural  state ;  wx  will  now  turn  to  domesti- 
cated animals;  first  touching  on  monstrosities  and  dis- 
eases.    The  presence  of  supernumerary  digits,  and  the 

mage,  and  to  a  considerable  degrco  in  tlic  spcculiun,  \\bicli  is  pure  white 
in  the  male  and  grayish-white  in  the  female.  Now  the  young  males  at 
first  resemble,  in  all  respects,  the  female,  and  have  a  grayish-white  spec- 
ulum, but  this  becomes  pure  white  at  an  earlier  age  than  that  at  which 
the  adult  male  acquires  his  other  more  strongly-marked  se.wial  diflfcr- 
ences  in  plumage:  sec  Audubon,  'Ornithological  Biography,'  vol.  iii. 
1835,  pp.  219,250. 


Chap.  VIII.]  SEXUAL  SELECTION.  283 

absence  of  certain  phalanges,  must  be  determined  at  an 
early  embryonic  period — the  tendency  to  profuse  bleeding 
is  at  least  congenital,  as  is  probably  color-blindness — yet 
these  peculiarities,  and  other  similar  ones,  are  often  limit- 
ed in  their  transmission  to  one  sex  ;  so  that  the  rule  that 
characters  which  are  developed  at  an  early  period  tend  to 
be  transmitted  to  both  sexes,  here  wholly  fails.  But  this 
rule,  as  before  remarked,  does  not  appear  to  be  nearly  so 
generally  true  as  the  converse  proposition,  namely,  that 
characters  which  appear  late  in  life  in  one  sex  are  trans- 
mitted exclusively  to  the  same  sex.  From  the  fact  of  the 
above  abnormal  peculiarities  becoming  attached  to  one 
sex,  long  before  the  sexual  functions  are  active,  we  may 
infer  that  there  must  be  a  difference  of  some  kind  between 
the  sexes  at  an  extremely  early  age.  With  respect  to 
sexually-limited  diseases,  we  know  too  little  of  the  period 
at  which  they  originate,  to  draw  any  fair  conclusion. 
Gout,  however,  seems  to  fall  under  our  rule  ;  for  it  is  gen- 
erally caused  by  intemperance  after  early  youth,  and  is 
transmitted  from  the  father  to  his  sons  in  a  much  more 
marked  manner  than  to  his  daughters. 

In  the  various  domestic  breeds  of  sheep,  goats,  and 
cattle,  the  mules  differ  from  their  respective  females  in 
the  shape  or  development  of  their  horns,  forehead,  mane, 
dewlap,  tail,  and  hump  on  the  shoulders  ;  and  these  pecu- 
liarities, in  accordance  with  our  rule,  are  not  fully  devel- 
oped until  rather  late  in  life.  With  dogs,  the  sexes  do 
not  differ,  except  that  in  certain  breeds,  especially  in  the 
Scotch  deer-hound,  the  male  is  much  larger  and  heavier 
than  the  female  ;  and,  as  we  shall  see  in  a  future  chapter, 
the  male  goes  on  increasing  in  size  to  an  imusually  late 
period  of  life,  which  will  account,  according  to  our  rule, 
for  his  increased  size  being  transmitted  to  his  male  off- 
spring alone.  On  the  other  hand,  the  tortoise-shell  color 
of  the  hair,  which  is  confined  to  female  cats,  is  quite  dis- 


284  THE  rRINCIPLES  OF  [Pakt  II. 

tiuct  at  birth,  and  this  case  violates  our  rule.  There  is  a 
hreccl  of  pigeons  in  which  the  males  alone  arc  streaked 
Avilh  black,  and  the  streaks  can  be  detected  even  in  the 
nestlings ;  but  they  become  more  conspicuous  at  each  suc- 
cessive moult,  so  that  this  case  partly  opposes  and  partly 
supports  the  rule.  With  the  English  Carrier  and  Pouter 
])igeon  the  full  development  of  the  wattle  and  the  crop 
occurs  rather  late  in  life,  and  these  characters,  conform- 
ably with  our  rule,  are  transmitted  in  full  perfection  to 
the  males  alone.  The  following  cases  j^erhaps  come  with- 
in the  class  previously  alluded  to,  in  which  the  two  sexes 
have  varied  in  the  same  manner  at  a  rather  late  period  of 
life,  and  have  consequently  transferred  their  new  charac- 
ters to  both  sexes  at  a  corresponding  late  period  ;  and  if 
so,  such  cases  are  not  opjiosed  to  our  rule.  Thus  there 
are  sub-breeds  of  the  pigeon,  described  by  Neumeister,^" 
both  sexes  of  which  change  color  after  moulting  twice  or 
thrice,  as  does  likewise  the  Almond  Tumbler ;  neverthe- 
less these  changes,  though  occurring  rather  late  in  life, 
arc  common  to  both  sexes.  One  variety  of  the  Canary-bii'd, 
namely,  the  London  Prize,  offers  a  nearly  analogous  case. 
With  the  breeds  of  the  Fowl  the  inheritance  of  various 
characters  by  one  sex  or  by  both  sexes  seems  generally 
determined  by  the  period  at  which  such  characters  are 
developed.  Thus,  in  all  the  many  breeds  in  which  the 
adult  male  differs  greatly  in  color  from  the  female  and 
from  the  adult  male  parent-species,  he  differs  from  the 
young  male,  so  that  the  newly-acquired  characters  must 
have  appeared  at  a  rather  late  period  of  life.  On  the 
other  hand,  with  most  of  the  breeds  in  which  the  two 
sexes  resemble  each  other,  the  young  are  colored  in  nearly 
the  same  manner  as  their  parents,  and  this  renders  it  proba- 

80  'Das  Ganzc  der  Tuubcnzucbt,'  1837,  s.  21,  24.  For  the  case  of  the 
streaked  pigeons,  sec  Dr.  Chapuis,  '  Le  Pigeon  Voyageur  13elge,'  18G5, 
p.  87. 


CuAP.  VIII.]  SEXUAL  SELECTION.  285 

l)lc  tliat  their  colors  first  appeared  early  in  life.  We  have 
instances  of  this  fact  in  all  black  and  white  breeds,  in 
which  the  young  and  old  of  both  sexes  are  alike  ;  nor  can 
it  be  maintained  that  there  is  something  peculiar  in  a 
l)lack  or  white  plumage,  leading  to  its  transference  to 
both  sexes  ;  for  the  males  alone  of  many  natural  species 
are  either  black  or  white,  the  females  being  very  differ- 
ently colored.  With  the  so-called  Cuckoo  sub-breeds  of 
the  fowl,  in  which  the  feathers  ai'e  transversely  pencilled 
with  dark  stripes,  both  sexes  and  the  chickens  are  colored 
in  nearly  the  same  manner.  The  laced  plumage  of  the 
Sebright  bantam  is  the  same  in  both  sexes,  and  in  the 
chickens  the  feathers  are  tipped  with  black,  which  makes 
a  near  approach  to  lacing.  Spangled  Hamburgs,  however, 
ofter  a  partial  exception,  for  the  two  sexes,  though  not 
quite  alike,  resemble  each  other  more  closely  than  do  the 
sexes  of  the  aboriginal  parent-species,  yet  they  acquire 
their  characteristic  plumage  late  in  life,  for  the  chickens 
are  distinctly  pencilled.  Turning  to  other  characters  be- 
sides color :  the  males  alone  of  the  wild  parent-species  and 
of  most  domestic  breeds  possess  a  fairly  well-developed 
comb,  but  in  the  young  of  the  Spanish  fowl  it  is  largely 
developed  at  a  very  early  age,  and  apparently  in  conse- 
quence of  this  it  is  of  unusual  size  m  the  adult  females. 
In  the  Game  breeds  pugnacity  is  developed  at  a  wonder- 
fully early  age,  of  which  curious  proofs  could  be  given  ; 
and  this  character  is  transmitted  to  both  sexes,  so  that 
the  hens,  from  their  extreme  pugnacity,  are  now  generally 
exhibited  in  separate  pens.  With  the  Polish  breeds  the 
bony  protuberance  of  the  skull  which  supports  the  crest  is 
partially  developed  even  before  the  chickens  are  hatched, 
and  the  crest  itself  soon  begins  to  grow,  though  at  first 
feebly;"  and  in  this  breed  a  great  bony  protuberance 

31  For  full  particulars  and  references  on  all  these  points  respectiuj^ 
the  several  breeds  of  the  Fowl,  see  '  Variation  of  Animals  and  Flants  un- 


28G  THE   rrvINCirLES   OF  [Paut  II 

mul  an  iininciisc   crest  cliaractcrizc   tlic  adults  of  botli 
sexes. 

Finally,  from  what  wc  have  now  seen  of  t-lic  relation 
Avhich  exists  in  many  natural  species  and  domesticated 
races,  between  the  period  of  the  development  of  their 
characters  and  the  manner  of  their  transmission — for  ex- 
ample, the  striking  fact  of  the  early  growth  of  the  horns 
in  tlie  reindeer,  in  which  both  sexes  have  horns,  in  com- 
liarison  with  their  much  later  grow^th  in  the  other  species 
in  which  the  male  alone  bears  horns — we  may  conclude 
that  one  cause,  though  not  the  sole  cause,  of  characters 
being  exclusively  inherited  by  one  sex,  is  their  develop- 
ment at  a  late  age.  And  secondly,  that  one,  though  ap- 
])arently  a  less  efficient,  cause  of  characters  being  in- 
herited by  both  sexes  is  their  development  at  an  early 
age,  while  the  sexes  differ  but  little  in  constitution.  It 
appears,  however,  that  some  difference  must  exist  between 
the  sexes  even  during  an  early  embryonic  period,  for  char- 
acters developed  at  this  age  not  rarely  become  attached 
to  one  sex. 

Summary  and  conclucling  remarJcs, — From  the  fore- 
going discussion  on  the  various  laAVS  of  inheritance,  we 
learn  that  characters  often  or  even  generally  tend  to  be- 
come developed  in  the  same  sex,  at  the  same  age,  and  pe- 
riodically at  the  same  season  of  the  year,  in  which  they 
first  appeared  in  the  parents.  But  these  laws,  from  un- 
known causes,  are  very  liable  to  change.  Hence  the  suc- 
cessive stcjis  in  the  modification  of  a  species  might  readily 
be  transmitted  in  different  ways  ;  some  of  the  steps  being 
transmitted  to  one  sex,  and  some  to  both ;  some  to  the 
oflspring  at  one  age,  and  some  at  all  ages.     Not  only  arc 

dcr  Domestication,'  vol.  i.  pp.  250,  256.  In  regard  to  the  higher  ani- 
mals, the  sexual  difTercnces  ^Yllich  have  arisen  under  domestication  arc 
described  in  the  same  work  under  the  head  of  each  species. 


CiiAP.  VIII.]  SEXUAL  SELECTION.  287 

the  laws  of  inheritance  extremely  complex,  but  so  are  the 
causes  which  induce  and  govern  variability.  The  varia- 
tions thus  caused  are  preserved  and  accumulated  by  sexual 
selection,  which  is  in  itself  an  extremely  complex  affair, 
depending,  as  it  does,  on  ardor  in  love,  courage,  and  the 
rivalry  of  the  males,  and  on  the  pov/ers  of  perception, 
taste,  and  will,  of  the  female.  Sexual  selection  will  also 
be  dominated  by  natural  selection  for  the  general  welfare 
of  the  species.  Hence  the  manner  in  which  the  individu- 
als of  either  sex  or  of  both  sexes  are  affected  through 
sexual  selection  cannot  fail  to  be  complex  in  the  highest 
degi'ce. 

When  variations  occur  late  in  life  in  one  sex,  and  are 
transmitted  to  the  same'^sex  at  the  same  age,  the  other  sex 
and  the  young  are  necessarily  left  unmodified.  When 
they  occur  late  in  life,  but  are  transmitted  to  both  sexes 
at  the  same  age,  the  young  alone  are  left  unmodified. 
Variations,  however,  may  occur  at  any  period  of  life  in 
one  sex  or  in  both,  and  be  transmitted  to  both  sexes  at 
all  ages,  and  then  all  the  individuals  of  the  species  will 
be  similarly  modified.  In  the  following  chapters  it  will 
be  seen  that  all  these  cases  frequently  occur  under  nature. 

Sexual  selection  can  never  act  on  any  animal  while 
young,  before  the  age  for  reproduction  has  arrived.  From 
the  great  eagerness  of  the  male  it  has  generally  acted  on 
this  sex  and  not  on  the  females.  The  males  have  thus  be- 
come provided  with  weapons  for  fighting  with  their  rivals, 
or  with  organs  for  discovering  and  securely  holding  the 
female,  or  for  exciting  and  charming  her.  When  the  sexes 
differ  in  these  respects,  it  is  also,  as  we  have  seen,  an  ex- 
tremely general  law  that  the  adult  male  diflers  more  or 
less  from  the  young  male ;  and  we  may  conclude  from  this 
fact  that  the  successive  variations,  by  which  the  adult 
male  became  modified,  cannot  have  occurred  much  before 
the  age  for  reproduction.     How,  then,  are  we  to  account 


288  TDE  TRINCirLES   OF  [Part  II. 

for  tills  general  and  remarkable  coincidence  between  the 
period  of  variability  and  that  of  sexual  selection — princi- 
ples wliicli  are  quite  indejiendent  of  each  other?  I  think 
"wc  can  see  the  cause:  it  is  not  that  the  males  have  never 
varied  at  an  early  age,  but  that  such  variations  have  com- 
monly been  lost,  while  those  occurring  at  a  later  age  have 
been  preserved. 

All  animals  produce  more  offsprmg  than  can  survive 
to  maturity ;  and  we  have  every  reason  to  believe  that 
death  falls  heavily  on  the  weak  and  inexperienced  young. 
If,  then,  a  certain  proportion  of  the  offspring  were  to  vary 
at  birth  or  soon  aftervv^ard,  in  some  manner  Avhich  at  this 
age  was  of  no  service  to  them,  the  chance  of  the  preser- 
vation of  such  variations  would  be  small.  We  have  good 
evidence  under  domestication  how  soon  variations  of  all 
kinds  are  lost,  if  not  selected.  But  variations  which  oc- 
curred at  or  near  maturity,  and  which  were  of  immediate 
service  to  either  sex,  would  jirobably  be  preseiwed ;  as 
would  similar  variations  occurring  at  an  earlier  period  in 
any  individuals  which  happened  to  survive.  As  this  prin- 
ciple has  an  important  bearing  on  sexual  selection,  it  may 
be  advisable  to  give  an  imaginary  illustration.  -  We  will 
take  a  pair  of  animals,  neither  very  fertile  nor  the  reverse, 
and  assi;me  that  after  arriving  at  maturity  they  live  on  an 
average  for  five  years,  producing  each  year  five  young. 
They  would  thus  produce  25  offspring ;  and  it  would  not, 
I  think,  be  an  unfair  estimate  to  assume  that  18  or  20  out 
of  the  25  would  perish  before  maturity,  while  still  young 
and  inexperienced ;  the  remaining  seven  or  five  sufficing 
to  keep  up  the  stock  of  mature  individuals.  If  so,  we  can 
see  that  variations  which  occurred  during  youth,  for  in- 
stance, in  brightness,  and  Vtiiich  vrere  not  of  the  least  ser- 
vice to  the  young,  would  run  a  good  chance  of  being 
utterly  lost.  While  similar  variations,  which  occurring 
at  or  near  maturity  in  the  comparatively  few  individuals 


Chap.  VIII.]  SEXUAL   SELECTION.  289 

surviving  to  this  age,  and  which  immediately  gave  an  ad- 
vantage to  certain  males,  by  rendering  them  more  attrac- 
tive to  the  females,  would  be  likely  to  be  preserved.  No 
doubt  some  of  the  variations  in  brightness  which  occurred 
at  an  earlier  age  wovild  by  chance  be  preserved,  and 
eventually  give  to  the  male  the  same  advantage  as  those 
which  appeared  later ;  and  this  will  account  for  the  young 
males  commonly  partaking  to  a  certam  extent  (as  may  be 
observed  with  many  birds)  of  the  bright  colors  of  their 
adult  male  parents.  If  only  a  few  of  the  successive  varia- 
tions in  brightness  were  to  occur  at  a  late  age,  the  adult 
male  would  be  only  a  little  brighter  than  the  young  male ; 
and  such  cases  are  common. 

In  this  illustration  I  have  assumed  that  the  young 
varied  in  a  manner  which  was  of  no  service  to  them ;  but 
many  characters  proper  to  the  adult  male  would  be  actu- 
ally injurious  to  the  young — as  bright  colors  from  making 
them  conspicuous,  or  horns  of  large  size  from  expending 
much  vital  force.  Such  variations  in  the  young  would 
promptly  be  eliminated  through  natural  selection.  With 
the  adult  and  experienced  males,  on  the  other  hand,  the 
advantage  thus  derived  in  their  rivalry  with  other  males 
would  often  more  than  counterbalance  exposure  to  some 
degree  of  danger.  Thus  we  can  understand  how  it  is  that 
variations  which  must  originally  have  appeared  rather  late 
in  life  have  alone  or  in  chief  part  been  preserved  for  the 
development  of  secondary  sexual  characters  ;  and  the  re- 
markable coincidence  between  the  periods  of  variability 
and  of  sexual  selection  is  intelligible. 

As  variations  which  give  to  the  male  an  advantage  in 
fighting  with  other  males,  or  in  finding,  securing,  or  charm- 
ing the  female,  would  be  of  no  use  to  the  female,  they  will 
not  have  been  preserved  in  this  sex  either  during  youth  or 
maturity.  Consequently  such  valuations  would  be  ex- 
tremely liable  to  be  lost ;  and  the  female,  as  far  as  these 


290  THE   PRINCirLES  OF  [Paut  II. 

characters  arc  couccruetl,  would  be  left  unmodified,  except- 
ing in  60  far  as  she  may  have  received  them  by  transference 
from  the  male.  No  doubt  if  the  female  varied  and  trans- 
ferred serviceable  characters  to  her  male  oftspring,  these 
would  be  favored  through  sexual  selection ;  and  then  both 
sexes  would  thus  far  be  modified  in  the  same  manner.  But 
I  shall  hereafter  have  to  recur  to  these  more  intricate  con- 
tingencies. 

In  the  following  chapters,  I  shall  treat  of  tlie  secondary 
sexual  characters  in  animals  of  all  classes,  and  shall  en- 
deavor in  each  case  to  apply  the  principles  explained  in 
the  present  chapter.  The  lowest  classes  Avill  detain  us  for 
a  very  short  time,  but  the  higher  animals,  especially  birds, 
must  be  treated  at  considerable  length.  It  should  be  borne 
in  mind  that,  for  reasons  already  assigned,  I  intend  to  give 
only  a  few  illustrative  instances  of  the  innumerable  struct- 
ures by  the  aid  of  which  the  male  finds  the  female,  or, 
when  found,  holds  hei-.  On  the  other  hand,  all  structures 
and  instincts  by  which  the  male  conquers  other  males, 
and  by  which  he  allures  or  excites  the  female,  will  be  fully 
discussed,  as  these  are  in  many  ways  the  most  interesting. 


Sup2^lement  on  the  proportional  numbers  of  the  tico  sexes 
in  animals  belonging  to  varioxis  classes. 

As  no  one,  as  far  as  I  can  discover,  has  paid  attention 
to  the  relative  numbers  of  the  two  sexes  throughout  the 
animal  kingdom,  I  will  here  give  such  materials  as  I  have 
been  able  to  collect,  although  they  arc  extremely  imper- 
fect. They  consist  in  only  a  few  instances  of  actual  enu- 
meration, and  the  numbers  arc  not  very  large.  As  the 
proportions  are  knoAvn  Avith  certainty  on  a  large  scale  in 
the  case  of  man  alone,  I  will  first  give  them,  as  a  standard 
of  comparison. 


Chap.  VIII.]  SEXUAL   SELECTION.  291 

3Ian. — In  England  during  ten  years  (from  1857  to 
1860)  707,120  children  on  an  annual  average  have  been 
born  alive,  in  the  proportion  of  104.5  males  to  100  fe- 
males. But  in  1857  the  male  births  throughout  England 
were  as  105.2,  and  1865  as  104.0  to  100.  Looking  to 
separate  districts,  in  Buckinghamshire  (where  on  an  aver- 
age 5,000  children  are  annually  born)  the  'mean  propor- 
tion of  male  to  female  births,  during  the  whole  period  of 
the  above  ten  years,. was  as  102.8  to  100  ;  while  in  North 
"Wales  (where  the  average  annual  births  are  12,873)  it  was 
as  high  as  106.2  to  100.  Taking  a  still  smaller  district, 
viz.,  Rutlandshire  (where  the  annual  births  average  only 
739),  in  1864  the  male  births  were  as  114.6,  and  in  1862  as 
97.0  to  100;  but  even  in  this  small  district  the  average  of 
the  7,385  bu'ths  during  the  whole  ten  years  was  as  104.5 
to  100  ;  that  is,  m  the  same  ratio  as  throughout  Eugland.^^ 
The  proportions  are  sometimes  slightly  disturbed  by  un- 
known causes ;  thus  Prof.  Faye  states  that  "  in  some  dis- 
tricts of  Norway  there  has  been  during  a  decennial  period 
a  steady  deficiency  of  boys,  while  in  others  the  opposite 
condition  has  existed."  In  France  during  forty-four  years 
the  male  to  the  female  births  have  been  as  106.2  to  100; 
bu.t  during  this  period  it  has  occurred  five  times  in  one  de- 
partment, and  six  times  in  another,  that  the  female  births 
have  exceeded  the  males.  In  Russia  the  average  propor- 
tion is  as  high  as  108.9  to  100."  It  is  a  singular  fact  that 
with  Jews  the  proportion  of  male  births  is  decidedly  larger 
than  with  Christians  ;  thus  in  Pi'ussia  the  proportion  is  as 
113,  in  Breslau  as  114,  and  in  Livonia  as  120  to  100;  the 
Christian  births  in  these  countries  being  the  same  as  usual, 

3-  '  Twentj'-ninth  Annual  Report  of  the  Registrar-General  for  18G6.' 
Ill  this  report  (p.  xii)  a  special  decennial  table  is  given. 

^  For  Norway  and  Russia,  see  abstract  of  Prof.  Faye's  researches  in 
'British  and  Foreign  Medico-Chirurg.  Review,'  April,  1867,  pp.  343,  345 
For  France,  the  '  Annuaire  pour  I'An  18G7,'  p.  213. 


292  THE   rniNCIPLES   OF  [Part  II. 

for  instance,  in  Livonia  as  104  to  100."  It  is  a  still  more 
singnlar  fact  that  in  different;  nations,  under  different  con- 
ditions and  climates,  in  Naples,  Prussia,  AV^estplialia, 
France,  and  England,  the  excess  of  male  over  female 
births  is  less  when  they  arc  illegitimate  than  when  legiti- 
mate.°* 

In  various  parts  of  Europe,  according  to  Prof.  Fayc 
and  other  authors, "  a  still  greater  preponderance  of  males 
would  be  met  with,  if  death  struck  both  sexes  in  equal 
proportion  in  the  womb  and  during  birth.  But  the  fact 
is  that,  for  every  100  still-born  females,  we  have  in  sev- 
eral countries  from  134.6  to  144.9  still-born  males."  More- 
over during  the  first  four  or  five  years  of  life  more  male 
children  die  than  females ;  for  examj^le,  in  England,  dur- 
ing the  first  year,  126  boys  die  for  every  100  girls — a  pro- 
portion which  in  France  is  still  more  unfavorable." '°  As 
a  consequence  of  this  excess  in  the  death-rate  of  male 
children,  and  of  the  exposure  of  men  when  adult  to  vari- 
ous dangers,  and  of  their  tendency  to  emigrate,  the  fe- 
males in  all  old-settled  countries,  where  statistical  records 
have  been  kept,"  arc  found  to  preponderate  considerably 
over  the  males. 

^  In  regard  to  the  Jews,  see  M.  Tbury,  '  La  Loi  de  Production  des 
^'cxes,'  18G3,  p.  25. 

^^  Babbage,  '  Edinburgli  Journal  of  Science,'  1820,  vol.  i.  p.  88;  also 
p.  90,  on  still-born  children.  On  illegitimate  children  in  England,  sec 
'Report  of  Registrar-General  for  18GG,'  p.  xv. 

*''  'British  and  Foreign  Medico-Chirurg.  Rcviev/,'  April,  1807,  p.  343. 
Dr.  Stark  also  remarks  ('Tenth  Annual  Report  of  Births,  Deaths,  etc.,  in 
Scotland,'  1867,  p.  xxviii.)  that  "these  examples  may  suffice  to  show  that, 
at  almost  every  stage  of  life,  the  males  in  Scotland  have  a  greater  liabil- 
ity to  death  and  a  higher  death-rate  than  the  females.  The  fact,  how- 
ever, of  this  peculiarity  being  most  strongly  developed  at  that  infantile 
period  of  Ufe  when  the  dress,  food,  and  general  treatment  of  both  sexes 
are  alike,  seems  to  prove  that  the  higher  male  death-rate  is  an  impressed, 
natural,  and  constitutional  peculiarity  due  to  sex  alone." 

•*'  With  the  savage  Guaranys  of  Paraguay,  according  to  the  accurate 


Chap.  VIII.]  SEXUAL  SELECTION.  293 

It  has  often  been  supposed  that  the  relative  ages  of 
the  parents  determine  the  sex  of  the  offspring  ;  and  Prof. 
Leuckart  ^®  has  advanced  what  he  considers  sufficient  evi- 
dence, with  respect  to  man  and  certain  domesticated  ani- 
mals, to  show  that  this  is  one  important  factor  in  the 
result.  So,  again,  the  period  of  impregnation  has  been 
thought  to  be  the  efficient  cause ;  but  recent  observations 
discountenance  this  belief.  Again,  with  mankind  polyg- 
amy has  been  supposed  to  lead  to  the  birth  of  a  greater 
proportion  of  female  infants  ;  but  Dr.  J.  Campbell^"  care- 
fully attended  to  this  subject  in  the  harems  of  Siam,  and 
he  concludes  that  the  proportion  of  male  to  female  births 
is  the  same  as  from  monogamous  unions.  Hardly  any 
animal  has  been  rendered  so  highly  polygamous  as  our 
English  race-horses,  and  we  shall  immediately  see  that 
their  male  and  female  offsjn-ing  are  almost  exactly  equal 
in  number. 

Horses. — Mr.  Tegetraeier  has  been  so  kind  as  to  tabulate  for 
me  from  the  '  Racing  Calendar '  the  births  of  race-horses  during 
a  period  of  twenty-one  years,  viz.,  from  1846  to  1867;  1849  being 
omitted,  as  no  returns  were  tliat  year  published.  The  total  births 
have  been  25,560,*°  consisting  of  12,763  males  and  12,797  females, 
or  in  the  proportion  of  99.7  males  to  100  females.     As  these  num- 

Azara  ('Voyages  dans  I'Amerique  merid.,'  tom.  ii.  1809,  pp.  60,  170), 
the  women  in  proportion  to  the  men  are  as  14  to  13. 

2S  Leuckart  (in  Wagner,  '  Handveorterbuch  der  Phys.'  B.  iv.  1853,  s. 
774). 

2^  Anthropological  Eeview,  April,  1870,  p.  cviii. 

*^  During  the  last  eleven  years  a  record  has  been  kept  of  the  number 
of  mares  which  have  proved  barren  or  prematurely  slipped  their  foals ; 
and  it  deserves  notice,  as  showing  how  infertile  these  highly-nurtured 
and  I'ather  closely-interbred  animals  have  become,  that  not  far  from  one- 
third  of  the  mares  failed  to  produce  living  foals.  Thus,  during  1866,  809 
male  colts  and  816  female  colts  were  born,  and  743  mares  failed  to  pro- 
duce offspring.  During  1867,  836  males  and  902  females  were  born,  and 
79-Jl  mares  failed. 


294  THE  PRINCIPLES   OF  [Part  II. 

bers  are  tolerably  large,  and  a3  they  arc  drawn  from  all  parts  of 
England,  during  several  years,  we  may  with  much  confidence 
conclude  that  with  the  domestic  horse,  or  at  least  with  the  race- 
horse, the  two  sexes  are  produced  in  almost  equal  numbers.  The 
fluctuations  in  the  proportions  during  successive  j'cars  are  closely 
like  those  Avhich  occur  with  mankind,  when  a  small  and  thinly- 
populated  area  is  considered:  thus  in  1856  the  mak-  horses  were 
as  107.1,  and  in  18G7  as  only  92.G  to  100  females.  In  the  tabu- 
lated returns  the  proportions  vary  in  cycles,  for  the  males  ex- 
ceeded the  females  during  six  successive  years ;  and  the  females 
exceeded  the  males  during  two  periods  each  of  four  years  :  this, 
however,  may  bo  accidental ;  at  least  I  can  detect  nothing  of  the 
kind  with  man  in  the  decennial  table  in  the  Registrar's  Report  for 
18GG.  I  may  add  that  certain  mares,  and  this  holds  good  with 
certain  cows  and  with  women,  tend  to  produce  more  of  one  sex 
than  of  the  other;  Mr.  "Wright,  of  Yeldersley  House,  informs  me 
that  one  of  his  Arab  mares,  though  put  seven  times  to  different 
horses,  produced  seven  fillies. 

Dogs. — During  a  period  of  twelve  years,  from  18.'J7  to  18G8, 
the  births  of  a  large  number  of  greyhounds,  throughout  England, 
have  been  sent  to  the  'Field'  newspaper;  and  I  am  again  in- 
debted to  Mr.  Tegetmeier  for  carefully  tabulating  the  results. 
The  recorded  births  have  been  6,878,  consisting  of  3,605  males 
and  3,273  females,  that  is,  in  the  proportion  of  110.1  males  to  100 
females.  The  greatest  fluctuations  occurred  in  ISG-i,  when  the 
proportion  was  as  95.3  males,  and  in  18G7,  as  11G.3  males  to  100 
females.  The  above  average  proportion  of  110.1  to  100  is  prob- 
ably nearly  correct  in  the  case  of  the  greyhound,  but  whether  it 
would  hold  with  other  domesticated  breeds  is  in  some  degree 
doubtful.  Mr.  Cupples  has  inquired  from  several  great  breeders 
of  dogs,  and  finds  that  all  without  exception  believe  that  females 
are  produced  in  excess;  ho  suggests  that  this  belief  may  have 
arisen  from  females  being  less  valued  and  the  consequent  disap- 
pointment producing  a  stronger  impression  on  tlie  mind. 

Sheep. — The  sexes  of  sheep  are  not  ascertained  by  agricultur- 
ists until  several  months  after  birth,  at  the  period  when  the  males 
are  castrated ;  so  that  the  following  retui'ns  do  not  give  the  pro- 
portions at  birth.  Moreover,  I  find  that  several  great  breeders 
in  Scotland,  who  annually  raise  some  thousand  sheep,  arc  firmly 


Chap.  VIII.]  SEXUAL   SELECTION.  295 

convinced  tliat  a  larger  proportion  of  males  than  of  females  die 
during  the  first  one  or  two  years ;  therefore  the  proportion  of 
males  would  be  somewhat  greater  at  birth  than  at  the  age  of  cas- 
tration. This  is  a  remarkable  coincidence  with  what  occurs,  as 
we  have  seen,  with  mankind,  and  both  cases  probably  depend  on 
some  common  cause.  I  have  received  returns  from  four  gentle- 
men in  England  who  have  bred  lowland  sheep,  chiefly  Leicesters, 
during  the  last  ten  or  sixteen  years ;  they  amount  altogether  to 
8,905  births,  consisting  of  4,407  males  and  4,558  females;  that  is, 
in  the  proportion  of  90. 7  males  to  100  females.  With  respect  to 
Cheviot  and  black-faced  sheep  bred  in  Scotland,  I  have  received 
returns  from  six  breeders,  two  of  them  on  a  large  scale,  chiefly 
for  the  years  1867-1809,  but  some  of  the  z-eturns  extending  back 
to  1862.  The  total  number  recorded  amounts  to  50,085,  consist- 
ing of  25,071  males  a,nd  25,014  females,  or  in  the  proportion  of 
97.9  males  to  100  females.  If  we  take  the  English  and  Scotch 
returns  together,  the  total  number  amounts  to  59,650,  consisting 
of  29,478  males  and  30,172  females,  or  as  97.7  to  100.  So  that 
with  sheep  at  the  age  of  castration  the  females  are  certainly  in 
excess  of  the  males;  but  whether  this  would  hold  good  at  birth 
is  doubtful,  owing  to  the  greater  liability  in  the  males  to  early 
death." 

Of  Cattle  I  have  received  returns  from  nine  gentlemen  of  982 
births,  too  few  to  be  trusted ;  these  consisted  of  477  bull-calves 
and  505  cow-calves ;  i.  e.,  in  the  proportion  of  94.4  males  to  100 
females.  The  Eev.  W.  D.  Fox  informs  me  that  in  1867  out  of  34 
calves  born  on  a  farm  in  Derbyshire  only  one  was  a  bull.  Mr. 
Harrison  "Weir  writes  to  me  that  he  has  inquired  from  several 
breeders  of  Pigs^  and  most  of  them  estimate  the  male  to  the  fe- 
male births  as  about  7  to  6.  This  same  gentleman  has  bred  Rab- 
lits  for  many  years,  and  has  noticed  that  a  far  greater  number  of 
bucks  are  produced  than  does. 

^'  I  am  much  indebted  to  Mr.  Cupples  for  having  procured  for  me  the 
above  returns  from  Scotland,  as  well  as  some  of  the  following  returns  on 
cattle.  Mr.  R.  Elliot,  of  Laighwood,  first  called  my  attention  to  the 
premature  deaths  of  the  males — a  statement  subsequently  confirmed  by 
Mr.  Aitchison  and  others.  To  this  latter  gentleman,  and  to  Mr.  Payan, 
I  OTvc  my  thanks  for  the  larger  returns  on  sheep. 


29G  THE   I'RINCirLES   OF  [1'aut  II. 

Of  iiiamiiialia  iii  a  state  of  nature  I  have  been  able  to  learn 
very  little.  In  regard  to  the  common  rat,  I  have  received  con- 
nit'ting  statements.  Mr.  R.  Elliot,  of  Laiglnvood,  informs  me  that 
a  rat-catcher  assured  him  that  he  had  always  found  the  males  in 
great  excess,  even  with  the  young  in  the  nest.  In  consequence 
of  this,  Mr,  Elliot  himself  subsequently  examined  some  hundred 
old  ones,  and  found  the  statement  true.  Mr.  F.  Buckland  has 
bred  a  large  number  of  white  rats,  and  ho  also  believes  that  the 
males  greatly  exceed  the  females.  In  regard  to  Moles,  it  is  said 
that  "the  males  are  much  more  numerous  than  the  females ;"^'- 
and  as  the  catching  of  these  animals  is  a  special  occupation,  tlie 
statement  may  perhaps  be  trusted.  Sir  A.  Smith,  in  describing 
an  antelope  of  South  Africa^'  (Kodus  ellipsipri/7nnus),  remarks, 
that  in  the  herds  of  this  and  other  species,  the  males  are  few  in 
number  compared  with  the  females:  the  natives  believe  that  they 
are  born  in  this  proportion ;  others  believe  that  the  3'ounger  males 
are  exi)elled  from  the  herds,  and  Sir  A.  Smith  says,  that  though 
he  has  himself  never  seen  herds  consisting  of  young  males  alone, 
others  affirm  that  this  does  occur.  It  appears  probable  that  the 
young  males,  when  expelled  from  the  herd,  would  be  likely  to  fall 
a  prey  to  the  many  beasts  of  prey  of  the  country. 

BIRDS. 

With  respect  to  the  Fotcl,  I  have  received  only  one  account, 
niimely,  that  out  of  1,001  chickens  of  a  highly-bred  stock  of  Co- 
chins, reared  during  eight  years  by  Mr.  Stretch,  487  proved  males 
and  514  females:  i.  e.,  as  94.7 to  100.  In  regard  to  domestic  pig- 
eons there  is  good  evidence  that  the  males  are  produced  in  excess, 
or  that  their  lives  are  longer;  for  these  birds  invariably  pair,  and 
single  males,  as  Mr.  Tegetmeier  informs  me,  can  alway  be  pur- 
chased cheaper  than  females.  Usually  the  two  birds  reared  from 
the  two  eggs  laid  in  the  same  nest  consist  of  a  male  and  female ; 
but  Mr,  Harrison  "Weir,  wlio  has  been  so  large  a  breeder,  says  that 
he  has  often  bred  two  cocks  from  the  same  nest,  and  seldom  two 
hens;  moreover,  the  hen  is  generally  the  weaker  of  the  two,  and 
more  liable  to  perish. 

42  Boll,  'lILstory  of  IJrIti.sh  Quadnipedi^,'  p.  100. 

■*"' Illustrations  of  the  Zoology  of  South  Africa,'  1849,  pi.  2'J. 


Chap.  VIII.]  SEXUAL   SELECTION.  297 

"With  respect  to  birds  in  a  state  of  nature,  Mr,  Gould  and 
others  "  are  convinced  that  the  males  are  generally  the  more 
numerous;  and  as  the  young  males  of  many  species  resemble  the 
females,  the  latter  would  naturally  appear  to  be  the  most  numer- 
ous. Large  numbers  of  pheasants  are  reared  by  Mr.  Baker,  of 
Leadenhall,  from  eggs  laid  by  wild  birds,  and  he  informs  Mr.  Jen- 
ner  Weir  that  four  or  five  males  to  one  female  are  generally  pro- 
duced. An  experienced  observer  remarks  *^  that  in  Scandinavia 
the  broods  of  the  capercailzie  and  black-cock  contain  more  males 
than  females ;  and  that  with  the  Dal-ripa  (a  kind  of  ptarmigan) 
moi'e  males  than  females  attend  the  lehs  or  places  of  courtship ; 
but  this  latter  circumstance  is  accounted  for  by  some  observers 
by  a  greater  number  of  hen-birds  being  killed  by  vermin.  From 
various  facts  given  by  White  of  Selbourne,*'' it  seems  clear  that  the 
males  of  the  partridge  must  be  in  considerable  excess  in  the  south 
of  England ;  and  I  have  been  assured  that  this  is  the  case  in  Scotr 
land.  Mr.  Weir,  on  inquiring  from  the  dealers  who  receive  at 
certain  seasons  large  numbers  of  ruffs  {Machetes  pugnax),  was  told 
that  the  males  are  much  the  most  numerous.  This  same  natural- 
ist has  also  inquired  for  me  from  the  bird-catchers,  who  annually 
catch  an  astonishing  number  of  various  small  species  alive  for  the 
London  market,  and  he  was  unhesitatingly  answered  by  an  old 
and  trustworthy  man,  that  with  the  chafiinch  the  males  are  in 
lai'ge  excess ;  he  thought  as  high  as  2  males  to  1  female,  or  at 
least  as  high  as  5  to  3."  The  males  of  the  blackbird,  he  likewise 
maintained,  were  by  far  the  most  numerous,  whether  caught  by 
traps  or  by  netting  at  night.  These  statements  may  apparently 
be  trusted,  because  the  same  man  said  that  the  sexes  are  about 
equal  with  the  lark,  the  twite  (Linaria  mo?itana),  and  goldfinch. 

*^  Brehm  ('  Illust.  Thierleben,'  B.  iv.  s.  990)  comes  to  the  same  con- 
clusion. 

■*5  On  the  authority  of  L.  Lloyd,  'Game  Birds  of  Sweden,'  1SG7,  pp. 
12,  132. 

^^  '  Nat.  Hist,  of  Selbourne,'  letter  xxis.  edit,  of  1825,  vol.  i.  p.  139. 

*'  Mr.  Jcnner  Weir  received  similar  information,  on  making  inquiries 
during  the  following  year.  To  show  the  number  of  chaffinches  caught,  I 
may  mention  that  in  1869  there  was  a  match  between  two  experts ;  and 
one  man  caught  in  a  day  62,  and  another  40,  male  chaffinches.  The 
greatest  number  ever  caught  by  one  man  in  a  single  day  was  VO. 


298  THE   rniNCIPLES  OF  [Part  II. 

On  tlio  other  haml,  he  is  certain  tliat  witli  the  common  linnet,  tlio 
females  preponderate  greatly,  but  unequally  during  different  years; 
during  some  years  he  has  found  the  females  to  the  males  as  four 
to  one.  It  should,  however,  be  borne  in  mind,  that  the  chief  sea- 
son for  catching  birds  docs  not  begin  till  September,  so  that  ■with 
some  species  partial  migrations  may  have  begiin,  and  the  flocks 
at  this  period  often  consist  of  hens  alone.  Mr.  Salvin  paid  par- 
ticular attention  to  the  sexes  of  the  humming-birds  in  Central 
America,  and  he  is  convinced  that  with  most  of  the  species  the 
males  ai'o  in  excess;  thus,  one  year  ho  procured  204  specimens 
belonging  to  ten  species,  and  these  consisted  of  1G6  males  and  of 
38  females.  "With  two  other  species  the  females  were  in  excess : 
but  the  proportions  apparently  vary  cither  during  different  sea- 
sons or  in  different  localities;  for  on  one  occasion  the  males  of 
Campyloptcrus  Tiemileucurus  were  to  the  females  as  five  to  two, 
and  on  another  occasion  "  in  exactly  the  reversed  ratio.  As  bear- 
ing on  this  latter  point,  I  may  add  that  Mr.  Powys  found  in  Corfu 
and  Epirus  the  sexes  of  the  cbaffmch  keeping  apart,  and  "  the  fe- 
males by  far  the  most  numerous;"  Avhile  in  Palestine  Mr.  Tris- 
tram found  "  the  male  flocks  appearing  greatly  to  exceed  the  fe- 
male in  number."  *'  So  again  with  the  Quiscalus  major,  Mr.  G. 
Taylor '"  says  that  in  Florida  there  were  "  very  few  females  in 
proportion  to  the  males,"  while  in  llonduras  the  proportion  was 
the  other  way,  the  species  there  having  the  character  of  a  i)0- 
lygamist. 

Fisn. 

"With  fish  the  proportional  numbers  of  the  sexes  can  be  ascer- 
tained only  by  catching  them  in  the  adult  or  nearly  adult  state  ; 
and  there  are  many  difficulties  in  arriving  at  any  just  conclusion. "^^ 
Infertile  females  miglit  readily  be  mistaken  for  males,  as  Dr.  Giin- 
ther  has  remai'kcd  to  me  in  regard  to  trout.     "With  some  species 

•"8  '  Ibis,'  vol  ii.  p.  260,  as  quoted  in  Gould's  '  Trochilidiv,'  18C1,  p.  52. 
For  the  foregoing  proportions,  I  am  indebted  to  Mr.  Salviu  for  a  table  of 
his  results. 

"  'Ibis,'  1800,  p.  137;  and  18C7,  p.  S09 

"iO'Ibis,'  18G2,  p.  187. 

*'  Lcuckart  quotes  Bloch  (Wagner,  'Ilandwurtctbuch  dor  ri.ys.' B. 
iv.  1853,  s.  775),  that  with  fish  there  arc  twice  as  many  males  as  females. 


Chap.  VIII.]  SEXUAL   SELECTION.  299 

the  males  are  believed  to  die  soou  after  fertilizing  the  ova.  "With 
many  species  the  males  are  of  much  smaller  size  than  the  females, 
so  that  a  large  number  of  males  would  escape  from  the  same  net 
by  which  the  females  were  caught.  M.  Carbonnier,^^  who  has 
especially  attended  to  the  natural  history  of  the  pike  {Esox  luchis) 
states  that  many  males,  owing  to  their  small  size,  are  devoured  by 
the  larger  females ;  and  he  believes  that  the  males  of  almost  all 
fish  are  exposed  from  the  same  cause  to  greater  danger  than  the 
females.  Nevertheless,  in  the  few  cases  in  which  the  proportional 
numbers  have  been  actually  observed,  the  males  appear  to  be 
largely  in  excess.  Thus,  Mr.  E.  Buist,  the  superintendent  of  the 
Stormontfield  experiments,  says  that  in  18G5,  out  of  70  salmon 
first  lauded  for  the  purpose  of  obtaining  the  ova,  upward  of  CO 
were  males.  In  18G7  he  again  "  calls  attention  to  the  vast  dispro- 
portion of  the  males  to  the  females.  "We  had  at  the  outset  at 
least  ten  males  to  one  female."  Afterward  sufiicicnt  females  for 
obtaining  ova  were  procured.  He  adds,  "  From  the  great  propor- 
tion of  the  males,  they  are  constantly  fighting  and  tearing  each 
other  on  the  spawning-beds."  ^^  This  disproportion,  no  doubt, 
can  be  accounted  for  in  part,  but  whether  wholly  is  very  doubtful, 
by  the  males  ascending  the  rivers  before  tlie  females.  Mr.  F. 
Buckland  remarks  in  regard  to  trout,  that  "it  is  a  curious  fact 
that  the  males  preponderate  very  largely  in  number  over  the  fe- 
males. It  invarially  happens  that  when  the  first  rush  of  fish  is 
made  to  the  net,  there  will  be  at  least  seven  or  eight  males  to  one 
female  found  captive.  I  cannot  quite  account  for  this ;  either  the 
males  are  more  numerous  than  the  females,  or  tlic  latter  seek 
safety  by  concealment  rather  than  flight."  He  then  adds  that,  by 
carefully  searching  the  banks,  suflicient  females  for  obtaining  ova 
can  be  found.'*  Mr.  II.  Lee  informs  me  that  out  of  212  trout, 
taken  for  this  purpose  in  Lord  Portsmouth's  park,  150  were  males 
and  62  females. 

"With  the  Cyprinidro  the  males  likewise  seem  to  be  in  excess; 
but  several  members  of  this  family,  viz.,  the  carp,  tench,  bream, 

52  Quoted  iu  the  'Farmer,'  March  18,  1869,  p.  369. 
6S  <  The  Stormontfield  PiscicuUural  Experiments,'  18G6,  p.  23.     Tho 
'Field'  newspaper,  June  29,  1867. 
^»  'Land  and  Water,'  1868,  p.  41. 


300  TUE  nilNCIPLES  OF  [Paut  II. 

and  minnow,  appear  regularly  to  follow  tlic  practice,  rare  in  the 
animal  kingdom,  of  polyandry;  for  the  female  while  spawning  is 
always  attended  by  two  males,  one  on  each  side,  and  in  the  case 
of  the  bream  by  three  or  four  males.  This  fact  is  so  well  known, 
that  it  is  always  recommended  to  stock  a  pond  with  two  male 
tenches  to  one  female,  or  at  least  with  three  males  to  two  females. 
With  the  minnow,  an  excellent  observer  states  that  on  the  spawn- 
ing-beds the  males  are  ten  times  as  numerous  as  the  females; 
when  a  female  comes  among  the  males,  "she  is  immediately 
pressed  closely  by  a  male  on  each  side ;  and  when  they  have  been 
in  that  situation  for  a  time,  are  superseded  by  other  two  males."  " 

INSECTS. 

In  this  class,  the  Lcpidoptera  alone  afford  the  means  of  judg- 
ing of  the  proportional  numbers  of  the  sexes ;  for  they  have  been 
collected  with  special  care  by  many  good  observers,  and  have 
been  largely  bred  from  the  egg  or  caterpillar  state.  I  had  hoped 
that  some  breeders  of  silk-moths  might  have  kept  an  exact  record, 
but  after  writing  to  France  and  Italy,  and  consulting  various 
treatises,  I  cannot  find  that  this  has  ever  been  done.  Tlie  gen- 
eral opinion  appears  to  be  that  the  sexes  are  nearly  equal,  but 
in  Italy,  as  I  hear  from  Prof.  Canestrini,  many  breeders  are 
convinced  that  the  females  are  produced  in  excess.  The  same 
naturalist,  however,  informs  me,  that  in  the  two  yearly  broods 
of  the  Ailantus  silk-moth  (Bomhjx  cyntlda)^  the  males  greatly 
preponderate  in  the  first,  while  in  the  second  the  two  sexes  arc 
nearly  equal,  or  the  females  rather  in  excess. 

In  regard  to  Butterflies  in  a  state  of  nature,  several  observers 
have  been  much  struck  by  the  apparently  enormous  preponder- 
ance of  the  males.^"    Thus  Mr.  Bates,"  in  speaking  of  the  species, 

'5  Yarrell,  '  Hist.  British  Fishes,'  vol.  i.  1836,  p.  307 ;  on  the  Ci/prinm 
carpio,  p.  331 ;  on  the  Tinea  vulyans,  p.  331 ;  on  the  Ahramh  brama,  p. 
336.  See,  for  the  minnow  {Leucisais  phozirnis),  '  Loudon's  Mag.  of  Xat. 
Hist.'  vol.  V.  1832,  p.  082. 

5"  Lcuckart  quotes  Mcinecke  (Wagner,  '  nandwiirtcrbuch  dor  Phys.' 
B.  iv.  1853,  s.  775)  that  with  Butterflies  the  males  arc  three  or  four 
times  as  numerous  as  the  females. 

"  '  The  Naturalist  on  the  Amazons,'  vol.  ii.  1863,  pp.  228,  347. 


Chap.  VIII.]  SEXUAL   SELECTION.  301 

no  less  than  about  a  hundred  in  number,  wliich  inliabit  the 
Upper  Amazons,  says  that  the  males  are  much  more  numerous 
than  the  females,  even  in  the  proportion  of  a  hundred  to  one. 
In  North  America,  Edwards,  who  had  great  experience,  esti- 
mates in  the  genus  Papilio  the  males  to  the  females  as  four  to 
one ;  and  Mr.  Walsh,  who  informed  me  of  this  statement,  says 
that  with  P.  turnus  this  is  certainly  the  case.  In  South  Africa, 
Mr.  R.  Trimen  found  the  males  in  excess  in  nineteen  species ;  ^^ 
and  in  one  of  these,  which  swarms  in  open  places,  he  estimated 
the  number  of  males  as  fifty  to  one  female.  With  another  spe- 
cies, in  which  the  males  are  numerous  in  certain  localities,  he 
collected  during  seven  years  only  five  females.  In  the  island  of 
Bourbon,  M.  Maillard  states  that  the  males  of  one  species  of 
Papilio  are  twenty  times  as  numerous  as  the  females.^'  Mr. 
Trimen  informs  me  that  as  far  as  he  has  himself  seen,  or  heard 
from  others,  it  is  rare  for  the  females  of  any  butterfly  to  exceed 
in  number  the  males ;  but  this  is  perliaps  the  case  with  three 
South  African  species.  Mr.  Wallace ""  states  that  the  females  of 
Ornitlioftera  ci'cesus,  in  the  Malay  archipelago,  are  more  common 
and  more  easily  caught  than  the  males  ;  but  this  is  a  rare  butter- 
fly. I  may  here  "add,  that  in  Ilyperythra,  a  genus  of  moths, 
Guen6e  says,  that  from  four  to  five  females  are  sent  in  collections 
from  India  for  one  male. 

When  this  subject  of  the  proportional  numbers  of  the  sexes 
of  insects  was  brought  before  the  Entomological  Society,^'  it  was 
generally  admitted  that  the  males  of  most  Lepidoptera,  in  the 
adult  or  imago  state,  are  caught  in  greater  numbers  than  the 
females ;  but  this  fact  was  attributed  by  various  observers  to  the 
more  retiring  habits  of  the  females,  and  to  the  males  emerging 
earlier  from  the  cocoon.  This  latter  circumstance  is  well  known 
to  occur  with  most  Lepidoptera,  as  well  as  with  other  insects. 
So  that,  as  M.  Personnat  remarks,  the  males  of  the  domesticated 
Bomlyx  yama-mai  arc  lost  at  the  beginning  of  the  season,  and 

^^  Four  of  these  cases  are  given  by  Mr.  Trimen  in  his  '  Rhopalocera 
Afrieae  Australis.' 

'"'Quoted  by  Trimen,  'Transact.  Ent.  Soc.'  vol.  v.  part  iv.  1866,  p. 
330. 

'''' '  Transact.  Linn.  Soc.'  vol.  xxv.  p.  3*7. 

•^' '  Troc.  Entomolog.  See.'  Feb.  11,  1868. 


302  THE   PRINCIPLES   OF  [Part  II. 

tlic  forn:ilcs  at  tho  cml,  from  the  want  of  mates/-  I  cannot,  how- 
ever, persuade  myself  tijat  these  causes  suffice  to  explain  the  great 
excess  of  males  in  the  cases,  above  given,  of  butterflies  which  are 
extremely  common  in  their  native  countries.  Mr.  Stainton,  who 
has  paid  such  close  attention  during  many  years  to  the  smaller 
moths,  informs  mo  that  when  ho  collected  them  in  the  imago 
state,  he  thought  that  the  males  were  ten  times  as  numerous  as 
tlie  females,  but  that,  since  ho  has  reared  them  on  a  largo  scale 
from  the  caterpillar  state,  he  is  convinced  that  the  females  are 
the  most  numerous.  Several  entomologists  concur  in  this  view. 
Mr.  Doubleday,  however,  and  some  others,  take  an  opposite  v\cvr, 
and  arc  convinced  that  they  have  reared  from  the  egg  and  cater- 
pillar states  a  larger  proportion  of  males  than  of  females. 

Besides  the  more  active  habits  of  the  males,  their  earlier 
emergence  from  the  cocoon,  and  their  frequenting  in  some  cases 
more  open  stations,  other  causes  may  be  assigned  for  an  apparent 
or  real  difference  in  the  proportional  numbers  of  the  sexes  of 
Lepidoptera,  when  captured  in  tho  imago  state,  and  when  reared 
from  the  egg  or  cateri)illar  state.  It  is  believed  by  many  breeders 
in  Italy,  as  I  hear  from  Prof.  Oanestrini,  that  the  female  cater- 
pillar of  the  silk-moth  suffers  more  from  tlie  recent  disease  tlian 
the  male ;  and  Dr.  Staudinger  informs  me  that  in  rearing  Lepi- 
doptera more  females  die  in  the  cocoon  than  males.  "With  many 
species  the  female  caterpillar  is  larger  than  the  male,  and  a  col- 
lector would  naturally  choose  the  finest  specimens,  and  thus  un- 
intentionally collect  a  larger  number  of  females.  Three  collect- 
ors have  told  me  that  this  was  their  practice ;  but  Dr.  TVallaco 
is  sure  that  most  collectors  take  all  the  specimens  which  they  can 
find  of  the  rarer  kinds,  which  alone  are  worth  the  trouble  of 
rearing.  Birds,  when  surrounded  by  cater])illars,  would  prob- 
ably devour  tho  largest ;  and  Prof.  Oanestrini  informs  me  that  in 
Italy  some  breeders  believe,  though  on  insufficient  evidence,  that 
in  tho  first  brood  of  tho  Ailantus  silk-moth,  the  wasps  destroy  a 
larger  number  of  the  female  than  of  the  male  caterpillars.  Dr. 
Wallace  further  remarks  that  female  caterpillars,  from  being 
larger  than  the  males,  require  more  time  for  their  development, 

•>*  Quoted  by  Dr.  Wallace  in  '  Pioc.  Eut.  Soc'  Sd  scries,  vol.  v.  18C7, 
p.  487. 


Chap.  VIII.]  SEXUAL   SELECTION.  303 

and  consume  more  food  and  moisture ;  and  thus  tlicy  would  bo 
exposed  during  a  longer  time  to  danger  from  ichneumons,  birds, 
etc.,  and  in  times  of  scarcity  would  perish  in  greater  numbers. 
Hence  it  appears  quite  possible  that,  in  a  state  of  nature,  fewer 
female  Lepidoptcra  may  reach  maturity  than  males  ;  and  for  our 
special  object  we  are  concerned  with  the  numbers  at  maturity, 
when  the  sexes  are  ready  to  propagate  their  kind. 

The  manner  in  which  the  males  of  certain  moths  congregate 
in  extraordinary  numbers  round  a  single  female,  apparently  indi- 
cates a  great  excess  of  males,  though  this  fact  may  perhaps  be 
accounted  for  by  the  earlier  emergence  of  the  males  from  their 
cocoons.  Mr.  Stainton  informs  me  that  from  twelve  to  twenty 
males  may  often  be  seen  congregated  round  a  female  Elachista 
rvfoeinerea.  It  is  well  known  that  if  a  virgin  Lasiocampa  quercus 
or  Saturnia  ca)yi7ii  be  exposed  in  a  cage,  vast  numbers  of  males 
collect  round  her,  and  if  confined  in  a  room  will  even  come  down 
the  chimney  to  her.  Mr.  Doubleday  believes  that  he  has  seen 
from  fifty  to  a  hundred  males  of  both  these  species  attracted  in 
the  course  of  a  single  day  by  a  female  under  confinement.  Mr. 
Trimen  exposed  in  the  Isle  of  Wight  a  box  in  which  a  female  of 
the  Lasiocampa  had  been  confined  on  the  previous  day,  and  five 
males  soon  endeavored  to  gain  admittance.  M.  Verreaux,  in 
Australia,  having  placed  the  female  of  a  small  Bombyx  in  a  box 
in  his  pocket,  was  followed  by  a  crowd  of  males,  so  that  about 
two  hundred  entered  the  house  with  him.^' 

Mr.  Doubleday  has  called  my  attention  to  Dr.  Staudinger's" 
list  of  Lepidoptera,  which  gives  the  prices  of  the  males  and 
females  of  800  species  or  well-marked  varieties  of  (Rhopalocera) 
butterflies.  The  prices  for  both  sexes  of  the  very  common  .species 
are  of  course  the  same ;  but  with  114  of  the  rarer  species  they 
differ ;  the  males  being  in  all  cases,  excepting  one,  the  cheapest. 
On  an  average  of  the  prices  of  the  113  species,  the  price  of  the 
male  to  that  of  the  female  is  as  100  to  149  ;  and  this  apparently 
indicates  that  inversely  the  males  exceed  the  females  in  number 
in  the  same  proportion.  About  2,000  species  or  varieties  of 
moths  (Ileterocera)  are  catalogued,  those  with  wingless  females 

^^  Blanchard, '  Metamorphoses,  Moeurs  des  Inscctcs,'  18C8,  pp.  225,  22G. 
^*  '  Lopidopteren-Doubblcttren  Liste,'  Berlin,  No.  x.  18G6. 


304  TUE   TRINCIPLES   OF  [Part  II. 

being  hero  excluded  on  account  of  tlie  difference  in  habits  of  the 
two  sexes  :  of  these  2,000  species,  141  differ  in  i)rice  according  to 
sex,  tlie  males  of  130  being  cheaper,  and  the  males  of  only  11 
being  dearer  than  the  females.  The  average  price  of  the  males 
of  the  130  species,  to  that  of  the  females,  is  as  100  to  143.  With 
respect  to  the  butterflies  in  this  priced  list,  Mr.  Doubleday  thinks 
(and  no  man  in  England  has  had  more  experience)  that  there  is 
nothing  in  the  habits  of  the  species  which  can  account  for  the 
difference  in  the  prices  of  the  two  sexes,  and  that  it  can  be  ac- 
counted for  only  by  an  excess  in  the  numbers  of  the  males.  But 
I  am  bound  to  add  that  Dr.  Staudinger  himself,  as  he  informs  me, 
is  of  a  different  opinion.  lie  thinks  that  the  less  active  habits  of 
the  females  and  the  earlier  emergence  of  the  males  will  account 
for  his  collectors  securing  a  larger  nimiber  of  males  than  of 
females,  and  consequently  for  the  lower  prices  of  the  former. 
"With  respect  to  specimens  reared  from  the  caterpillar-state,  Dr. 
Staudinger  believes,  as  previously  stated,  that  a  greater  number 
of  females  than  of  males  die  under  confinement  in  the  cocoons. 
He  adds  that  with  certain  species  one  sex  seems  to  preponderate 
over  the  other  during  certain  years. 

Of  direct  observations  on  the  sexes  of  Lepidoptera,  reared 
cither  from  eggs  or  caterpillars,  I  have  received  only  the  few  fol- 
lowing cases : 

Males.     F<?males. 

Tlic  Rev.  J.  Hc-llius,"  of  Exeter,  reared,  during  18C8,  images  of  73 

S])ecie8,  which  consisted  of 153  137 

Mr.  Albert  Jones,  of  Eltham,  reared,  during  1868,  imagos  of  9  species, 

which  consisted  of 159  12S 

Durini;  1869  he  reared  imagos  from  4  species,  consisting  of 114  112 

Mr.  Bucliler,  of  Emsworth,  Hants,  during  1869,  reared  imagos  from 

74  species,  consisting  of 180  169 

Dr.  Wallace,  of  Colchester,  reared  from  one  brood  of  Bombys 

Cynthia 53  48 

Dr.  Wallace  raised,  from  cocoons  of  Bombyx  Pernyi  sent  from 

China,  during  1860 221  123 

Dr.  ^\'allace  raised,  during  1868  and  1869,  from  two  lots  of  cocoons 

of  Bombyx  yaraa-mai 62  46 

Total 934  761 

So  that  in  these  eight  lots  of  cocoons  and  eggs,  m.ales  were 
produced  in  excess.     Taken  together,  the  proportion  of  males  is 

^'  Tlii.^  naturalist  has  been  so  kind  as  to  scud  mc  some  results  from 
former  years,  in  which  the  females  seemed  lo  preponderate;  but  so  many 
of  the  figures  were  estimates,  that  I  found  it  impossible  to  tabulate  them. 


Chap.  VIII.]  SEXUAL   SELECTION.  305 

as  122.7  to  100  females.  But  the  numbers  are  hardly  large 
enough  to  be  trustworthy. 

On  the  whole,  from  the  above  various  sources  of  evidence, 
all  pointing  to  the  same  direction,  I  infer  that,  with  most  species 
of  Lepidoptera,  the  males  in  the  imago  state  generally  exceed  the 
females  in  number,  whatever  the  proportions  may  be  at  their  first 
emergence  from  the  egg. 

With  reference  to  the  other  Orders  of  insects,  I  have  been 
able  to  collect  very  little  reliable  information.  "With  the  stag- 
beetle  {Lucanus  cermis)  "  the  males  appear  to  be  much  more 
numerous  than  the  females ; "  but  when,  as  Cornelius  remarked 
during  1867,  an  unusual  number  of  these  beetles  appeared  in  one 
part  of  Germany,  the  females  appeared  to  exceed  the  males  as 
six  to  one.  With  one  of  the  Elateridte,  the  males  are  said  to  be 
much  more  numerous  than  the  females,  and  "  two  or  three  are 
often  found  united  with  one  female;  "  '*  so  that  here  polyandry 
seems  to  prevail.  With  Siagonium  (Staphylinidie),  in  which  the 
males  are  furnished  with  horns,  "  the  females  are  far  more 
numerous  than  the  opposite  sex."  Mr.  Janson  stated  at  the 
Entomological  Society  that  the  females  of  the  bark-feeding 
Tomicus  villosus  are  so  common  as  to  be  a  plague,  while  the 
males  are  so  rare  as  to  be  hardly  known.  In  other  Orders,  from 
unknown  causes,  but  apparently  in  some  instances  owing  to 
parthenogenesis,  the  ujales  of  certain  species  have  never  been 
discovered,  or  are  excessively  rare,  as  with  several  of  the  Cyni- 
pidffi."  In  all  the  gall-making  Cynipidaj  known  to  Mr.  Walsh, 
the  females  are  four  or  five  times  as  numerous  as  the  males ;  and 
so  it  is,  as  he  informs  me,  with  the  gall-making  Cecidomyiife 
(Diptera).  With  some  common  species  of  Saw-flies  (Tenthre- 
dinaj)  Mr.  F.  Smith  has  reared  hundreds  of  specimens  from  larvai 
of  all  sizes,  but  has  never  reared  a  single  male  :  on  the  other 
hand,  Curtis  says,"^  that  with  certain  species  (Athalia),  bred  by 

«*  Giinther's  'Record  of  Zoological  Literature,'  1867,  p.  260.  On  the 
excess  of  female  Lucanus,  ibid.  p.  250.  On  the  males  of  Lucanus  in  Eng- 
land, Westwood,  'Modern  Class,  of  Insects,'  vol.  i.  p.  187.  On  the  Sia- 
gonium, ibid,  p  172. 

"  Walsh,  in  'The  American  Entomologist,'  vol.  i.  1869,  p.  103.  F 
Smith,  '  Record  of  Zoological  Literature,'  1867,  p.  328. 

'^  'Farm  Insects,'  pp.  45,  46. 
14 


30G  THE   PRINCIPLES  OF  [Part  II. 

liim,  the  males  to  tlic  females  were  as  six  to  one  ;  while  exactly 
the  reverse  occurred  with  the  mature  insects  of  the  same  species 
caught  in  the  fields.  "With  the  iN  europtera,  Mr.  "Walsh  states  that 
in  many,  but  by  no  means  in  all,  the  species  of  the  Odonatous 
groups  (Ephemerina),  there  is  a  great  overplus  of  males ;  in  the 
genus  Hctfcrina,  also,  the  males  are  generally  at  least  four  times 
as  numerous  as  the  females.  In  certain  species  in  the  genus 
Gomphus  the  males  are  equally  numerous,  while  in  two  other 
species  the  females  are  twice  or  thrice  as  numerous  as  the  males.  ■ 
In  some  European  species  of  Psocus  thousands  of  females  may  be 
collected  without  a  single  male,  while  with  other  species  of  the 
same  genus  both  sexes  are  common."  In  England,  Mr.  Mac- 
Lachlan  has  captured  hundreds  of  the  female  Ax>atania  muUebris, 
but  has  never  seen  the  male  ;  and  of  Boreus  hyemalis  only  four 
or  five  males  have  been  hero  seen.'"  With  most  of  these  species 
(excepting,  as  I  have  heard,  with  the  Tenlhredinai),  there  is  no 
reason  to  suppose  that  the  females  are  subject  to  parthenogene- 
sis ;  and  thus  we  see  how  ignorant  Ave  are  on  the  causes  of  the 
apparent  discrepancy  in  the  proportional  numbers  of  the  two 
sexes. 

In  the  other  Classes  of  the  Articulata  I  have  been  able  to  col- 
lect still  less  information.  "Witli  Spiders,  Mr.  Blackwall,  who  has 
carefully  attended  to  this  class  during  many  years,  writes  to  mo 
that  the  males,  from  their  more  erratic  habits,  are  more  com- 
monly seen,  and  therefore  appear  to  be  the  more  numerous. 
This  is  actually  the  case  with  a  few  species ;  but  he  mentions 
several  species  in  six  genera,  in  which  the  females  appear  to  bo 
much  more  numerous  than  the  males.^'  The  small  size  of  the 
males  in  comparison  with  the  females,  which  is  sometimes  car- 
ried to  an  extreme  degree,  and  their  widely-different  appearance, 
may  account  in  some  instances  for  their  rarity  in  collections.''* 

*'*'  '  Observations  on  N.  American  Xeuroptera,'  by  II.  Hagan  and  B.  D. 
Walsh,  'Proc.  Ent.  Soc.  Philadelphia,'  Oct.  18C3,  pp.  1G8,  223,  239. 

">  'Proc.  Ent.  Soc.  London,'  Feb.  17,  1808. 

■"  Another  great  authority  in  this  class,  Prof.  ThorcU  of  Upsala  ('  On 
European  Spiders,'  1869-'70,  part  i.  p.  205)  speaks  as  if  female  spiders 
were  generally  commoner  than  the  males. 

'-  See,  on  this  subject,  Mr.  Pickard-Cambridge,  as  quoted  in  '  Quar- 
terly Journal  of  Science,'  1808,  p.  120. 


Chap.  VIII.]  SEXUAL   SELECTION.  307 

Some  of  tlie  lower  Crustaceans  are  able  to  propagate  their 
kind  asexually,  and  tliis  will  account  for  the  extreme  rarity  of 
the  males.  With  some  other  forms  (as  with  Tanis  and  Cypris) 
there  is  reason  to  believe,  as  Fritz  Miiller  informs  me,  that  the 
male  is  much  shorter-lived  than  the  female,  which,  supposing 
the  two  sexes  to  be  at  lirst  equal  in  number,  would  explain  the 
scarcity  of  the  males.  On  the  other  hand,  this  same  naturalist 
has  invariably  taken,  on  the  shores  of  Brazil,  far  more  males 
than  females  of  the  Diastylida3  and  of  Cypridina;  thus,  with  a 
species  in  the  latter  genus,  sixty-three  specimens  caught  the 
same  day,  included  fifty-seven  males ;  but  he  suggests  that  this 
preponderance  may  be  due  to  some  unknown  difference  in  the 
habits  of  the  two  sexes.  With  one  of  the  higher  Brazilian  crabs, 
namely,  a  Gelasimus,  Fritz  Miiller  found  the  males  to  be  more 
numerous  than  the  females.  The  reverse  seems  to  be  the  case, 
according  to  the  large  experience  of  Mr.  C.  Spence  Bate,  with  six 
common  British  crabs,  the  names  of  which  he  has  given  me. 

On  the  Power  of  N'atural  Selection  to  regulate  the  pro- 
portional Numbers  of  the  Sexes,  and  General  Fertility. — 
In  some  peculiar  cases,  an  excess  in  the  number  of  one  sex 
over  the  other  might  be  a  great  advantage  to  a  species, 
as  with  the  sterile  females  of  social  insects,  or  with  those 
animals  in  which  more  than  one  male  is  requisite  to  ferti- 
lize the  female,  as  with  certain  cirripedes  and  perliaps 
certain  fishes.  An  inequality  between  the  sexes  in  these 
cases  might  have  been  acquired  through  natural  selection, 
but  from  their  rarity  they  need  not  here  be  further  con- 
sidered. In  all  ordinary  cases  an  inequality  would  be  no 
advantage  or  disadvantage  to  certain  individuals  more 
than  to  others;  and  therefore  it  could  hardly  have  re- 
sulted from  natural  selection.  We  must  attribute  the 
inequality  to  the  direct  action  of  tliose  unknown  condi- 
tions, which  with  mankind  lead  to  the  males  being  born 
in  a  somewhat  lai-ger  excess  in  certain  countries  than  in 
others,  or  which  cause  the  proportion  between  the  sexes 
to  differ  slightly  in  legitimate  and  illegitimate  births. 


308  THE  PRINCIPLES  OF  [Part  II. 

Let  us  now  take  the  case  of  a  species  producing,  from 
the  unlcnowu  causes  just  alluded  to,  an  excess  of  one  sex 
— we  will  say  of  males — these  being  superfluous  and  use- 
less, or  nearly  useless.  Could  the  sexes  he  equalized 
through  natural  selection  ?  "VVe  may  feel  sure,  from  all 
characters  being  variable,  that  certain  pairs  would  pro- 
duce a  somewhat  less  excess  of  males  over  females  than 
other  pairs.  The  former,  supposing  the  actual  number  of 
the  oSspring  to  remain  constant,  would  necessarily  pro- 
duce more  females,  and  would  therefore  be  more  pro- 
ductive. On  the  doctrine  of  chances  a  greater  number  of 
the  offspring  of  the  more  jiroductive  pairs  would  survive; 
and  these  would  inherit  a  tendency  to  procreate  fewer 
males  and  more  females.  Thus  a  tendency  toward  equali- 
zation of  the  sexes-  would  be  brought  about.  But  our 
supposed  species  would  by  this  j^rocess  be  rendered,  as 
just  remarked,  more  jiroductive ;  and  this  would  in  many 
cases  be  far  from  an  advantage  ;  for,  whenever  the  limit  to 
the  numbers  which  exist  dcj^ends,  not  on  destruction  by 
enemies,  but  on  the  amount  of  food,  increased  fertility 
will  lead  to  severer  competition  and  to  most  of  the  sur- 
vivors being  badly  fed.  In  this  case,  if  the  sexes  were 
equalized  by  an  increase  in  the  number  of  the  females,  a 
simultaneous  decrease  in  the  total  number  of  the  offspring 
would  be  beneficial,  or  even  necessary,  for  the  existence 
of  the  species ;  and  this,  I  believe,  could  be  effected  through 
natural  selection  in  the  manner  hereafter  to  be  described. 
The  same  train  of  reasoning  is  applicable  in  the  above,  as 
well  as  in  the  following  case,  if  wc  assume  that  females 
instead  of  males  are  produced  in  excess,  for  such  females 
froih  not  uniting  with  males  would  be  superfluous  and 
useless.  So  it  would  be  w4th  i.>olygamous  species,  if  we 
assume  the  excess  of  females  to  be  inordinately  great. 

An  excess  of  either  sex,  we  will  again  say  of  the  males, 
could,  however,  apparently  be  eliminated  through  natural 


CnAP.  VIII.]  SEXUAL   SELECTION.  309 

selection  in  another  and  indirect  manner,  namely,  by  an 
actual  diminution  of  the  males,  without  any  increase  of 
the  females,  and  consequently  without  any  increase  in  the 
productiveness  of  the  species.  From  the  variability  of  all 
chai-acters,  we  may  feel  assured  that  some  pairs,  inhabit- 
ing any  locality,  would  produce  a  rather  smaller  excess  of 
superfluous  males,  but  an  equal  number  of  productive 
females.  When  the  ofispring  from  the  more  and  the  less 
male-productive  parents  were  all  mingled  together,  none 
would  have  any  direct  advantage  over  the  others ;  but 
tliose  that  produced  few  superfluous  males  would  have 
one  great  indirect  advantage,  namely,  that  their  ova  or 
embryos  would  probably  be  larger  and  finer,  or  their 
young  better  nurtured  in  the  womb  and  afterward.  We 
see  this  principle  illustrated  with  plants ;  as  those  which 
bear  a  vast  number  of  seed  produce  small  ones ;  while 
those  which  bear  comparatively  few  seeds,  often  produce 
large  ones  well-stocked  with  nutriment  for  the  use  of  the 
seedlings."  Hence  the  ofispring  of  the  parents  which  had 
wasted  least  force  in  producing  superfiuous  males  would 
be  the  most  likely  to  survive,  and  would  inherit  the  same 
tendency  not  to  produce  superfiiious  males,  while  retain- 
ing their  full  fertility  in  the  production  of  females.  So  it 
would  be  with  the  converse  case  of  the  female  sex.  Any 
slight  excess,  however,  of  either  sex  could  hardly  be 
checked  in  so  indirect  a  manner.  Nor  indeed  has  a  con- 
siderable inequality  between  the  sexes  been  always  pre- 
vented, as  we  have  seen  in  some  of  the  cases  given  in  the 
previous  discussion.  In  these  cases  the  unknown  causes 
which  determine  the  sex  of  the  embryo,  and  which  under 
certain  conditions  lead  to  the  production  of  one  sex  in 

"  I  have  often  been  struck  with  the  fact  that,  in  several  species  of 
Primula,  the  seeds  in  the  capsules  which  contained  only  a  few  were 
very  much  larger  than  the  numerous  seeds  in  the  more  productive  cap- 

sules. 


310  THE   nilXCirLES   or  [Paut  II. 

excess  over  the  other,  have  not  been  mastered  by  the  sur- 
vival of  those  varieties  which  were  subjected  to  the  least 
waste  of  organized  matter  and  force  by  the  production  of 
sujoerfluous  individuals  of  either  sex.  Nevertheless  wo 
may  conclude  that  natural  selection  will  always  tend, 
though  sometimes  inefficiently,  to  equalize  the  relative 
numbers  of  the  two  sexes. 

Having  said  this  much  on  the  equalization  of  the 
sexes,  it  may  be  well  to  add  a  few  remarks  on  the  regula- 
tion through  natural  selection  of  the  ordinary  fertility  of 
species.  Mr.  Herbert  Spencer  has  shown  in  an  able  dis- 
cussion '*  that  with  all  organisms  a  ratio  exists  between 
what  lie  calls  individuation  and  genesis ;  whence  it  follows 
that  beings  which  consume  much  matter  or  force  in  their 
growth,  complicated  structure,  or  activity,  or  which  pro- 
duce ova  and  embryos  of  large  size,  or  which  expend 
much  energy  in  nurturing  their  young,  cannot  be  so  pro- 
ductive as  beings  of  an  opposite  nature.  Mr.  Spencer 
further  shows  that  minor  differences  in  fertility  will  be 
regulated  through  natural  selection.  Thus  the  fertility  of 
each  species  will  tend  to  increase,  from  the  more  fertile 
pairs  producing  a  larger  number  of  offspring,  and  these 
from  their  mere  number  will  have  the  best  chance  of  sur- 
viving, and  will  transmit  their  tendency  to  greater  fer- 
tility. The  only  check  to  a  continued  augmentation  of 
fertility  in  each  organism  seems  to  be  either  the  expendi- 
ture of  more  power  and  the  greater  risks  run  by  the 
parents  that  produce  a  more  numerous  progeny,  or  the 
contingency  of  very  numerous  eggs  and  young  being  pro- 
duced of  smaller  size,  or  less  vigorous,  or  subsequently 
not  so  well  mirtured.  To  strike  a  balance  in  any  case  be- 
tween the  disadvantages  which  follow  from  the  production 
of  a  numerous  progeny,  and  the  advantages  (such  as  the 

'■•  Tiinciplcs  of  Biology,'  vol.  ii.  1SG7,  cbiips.  ii.-xi. 


CiiAP.  VIII.]  SEXUAL   SELECTION.  Gil 

escai^e  of  at  least  some  iudivicluals  from  various  dangers) 
is  quite  beyond  our  j)ower  of  judgment. 

When  an  organism  has  once  been  rendered  extremely 
fertile,  how  its  fertility  can  be  reduced  through  natural 
selection  is  not  so  clear  as  how  this  capacity  was  first  ac- 
quired. Yet  it  is  obvious  that  if  individuals  of  a  species, 
from  a  decrease  of  their  natural  enemies,  were  habitually 
reared  in  larger  numbei's  than  could  be  supported,  all  the 
members  would  suifer.  Nevertheless  the  offspring  from 
the  less  fertile  parents  would  have  no  direct  advantage 
over  the  offspring  from  the  more  fertile  parents,  when  all 
were  mingled  together  in  the  same  district.  All  the  in- 
dividuals would  mutually  tend  to  starve  each  other.  The 
offspring  indeed  of  the  less  fertile  pai*ents  would  lie  under 
one  great  disadvantage,  for,  from  the  simple  fact  of  being 
produced  in  smaller  numbers,  they  would  be  the  most  lia- 
ble to  extermination.  Indirectly,  however,  they  would 
partake  of  one  great  advantage ;  for,  under  the  supposed 
condition  of  severe  competition,  when  all  were  pressed  for 
food,  it  is  extremely  probable  that  those  individuals  which 
from  some  variation  in  their  constitution  produced  fewer 
eggs  or  young,  would  produce  them  of  greater  size  or 
vigor;  and  the  adults  reared  from  such  eggs  or  young- 
would  manifestly  have  the  best  chance  of  surviving,  and 
would  inherit  a  tendency  toward  lessened  fertility.  The 
parents,  moreover,  which  had  to  nourish  or  provide  for 
fewer  offspring  would  themselves  be  exposed  to  a  less  se- 
vere strain  in  the  struggle  for  existence,  and  would  have 
a  better  chance  of  surviving.  By  these  steps,  and  by  no 
others  as  far  as  I  can  see,  natural  selection,  \inder  the 
above  conditions  of  severe  competition  for  food,  would 
lead  to  the  formation  of  a  new  race  less  fertile,  but  better 
adapted  for  survival,  than  the  parent-iace. 


312  SEXUAL   SELECTION  [I'Ar.T  IL 


CHAPTER    IX. 

SECONDARY    SEXUAL     CHARACTERS    11^   THE   LOAVER    CLASSES 
OP   THE    AXIMAX   KIXGDOiL 

These  Characters  absent  in  the  Lowest  Classes. — Brilliant  Colors. — Mol- 
lusca. — Annelids. — Crustacea,  Secondary  Sexual  Characters  strongly 
developed;  Dimorphism;  Color;  Characters  not  acquired  before 
Maturity. — Spiders,  Sexual  Colors  of;  Stridulation  by  the  Males. — 
Myriapoda. 

Lsr  tlie  lowest  classes  llie  Uvo  sexes  are  not  rarely 
united  in  the  same  individual,  and  therefore  secondary 
sexual  characters  cannot  be  develoi)ed.  In  many  cases  in 
which  the  two  sexes  are  sej^arate,  both  are  permanently 
attached  to  some  support,  and  the  one  cannot  search  or 
struggle  for  the  other.  Moreover,  it  is  almost  certain  that 
these  animals  have  too  imperfect  senses  and  much  too  low 
mental  powers  to  feel  mutual  rivalry,  or  to  appreciate  each 
other's  beauty  or  other  attractions. 

Hence  in  these  classes,  such  as  the  Protozoa,  Ccelen- 
terata,  Echinodermata,  Scolccida,  true  secondary  sexual 
characters  do  not  occur;  and  this  fact  agrees  with  the 
belief  that  such  characters  in  the  higher  classes  have  been 
acquired  through  sexual  selectiou,  which  depends  on  the 
will,  desires,  and  choice,  of  cither  sex.  Xevertheless  some 
few  apparent  exceptions  occur ;  thus,  as  I  hear  from  Dr. 
Baird,  the  males  of  certain  Entozoa,  or  internal  parasitic 
Avorms,  difter  slightly  in  color  from  the  females  ;  but  we 


Chap.  IX.]  SEXUAL  SELECTION.  313 

have  no  reason  to  suppose  that  such  differences  have  been 
augmented  through  sexual  selection. 

Many  of  the  lower  animals,  whether  hermaphrodites 
or  with  the  sexes  separate,  are  ornamented  with  the  most 
brilliant  tints,  or  are  shaded  and  striped  in  an  elegant 
manner.  This  is  the  case  with  many  corals  and  sea-anem- 
ones (Actiness),  with  some  jelly-fisli  (Medusa,  Porpita, 
etc.),  with  some  Planariae,  Ascidians,  numerous  Star-fishes, 
Echini,  etc. ;  but  we  may  conclude,  from  the  reasons  al- 
ready indicated,  namely,  the  union  of  the  two  sexes  in 
some  of  these  animals,  the  permanently  affixed  condition 
of  others,  and  the  low  mental  powers  of  all,  that  such  col- 
ors do  not  serve  as  a  sexual  attraction,  and  have  not  been 
acquired  through  sexual  selection.  With  the  higher  ani- 
mals the  case  is  very  different ;  for  with  them  when  one 
sex  is  much  more  brilliantly  or  conspicuously  colored  than 
the  other,  and  there  is  no  difference  in  the  habits  of  the 
two  sexes  Avhich  will  account  for  this  difference,  we  have 
reason  to  believe  in  the  influence  of  sexual  selection  ;  and 
this  belief  is  strongly  confirmed  when  the  more  ornament- 
ed individuals,  which  are  almost  always  the  males,  dis- 
play their  attractions  before  the  other  sex.  We  may  also 
extend  this  conclusion  to  both  sexes,  when  colored  alike, 
if  their  colors  are  plainly  analogous  to  those  of  one  sex 
alone  in  certain  other  species  of  the  same  group. 

•  How,  then,  ai"e  we  to  account  for  the  beaiitiful  or  even 
gorgeous  colors  of  many  animals  in  the  lowest  classes  ? 
It  appears  very  doubtful  whether  such  colors  usually  serve 
as  a  protection ;  but  we  are  extremely  liable  to  err  in  i-e- 
gard  to  characters  of  all  kinds  in  relation  to  protection,  as 
v/ill  be  admitted  by  every  one  who  has  read  Mr.  Wal- 
lace's excellent  essay  on  this  subject.  It  would  not,  for 
instance,  at  first  occur  to  any  one  that  the  perfect  trans- 
parency of  the  Medusas,  or  jelly-fishes,  was  of  the  highest 
service  to  them  as  a  protection  ;  but  when  we  arc  remind- 


314  SEXUAL  SELECTION.  [Pakt  II. 

ed  by  Hiickcl  that  not  only  the  meclusoe  but  many  float- 
ing niollusca,  crustaceans,  and  even  small  oceanic  fishes 
partake  of  this  same  glass-like  structure,  we  can  hardly 
doubt  that  they  thus  escape  the  notice  of  pelagic  birds  and 
ether  enemies. 

Notwithstanding  our  ignorance  how  far  color  in  many 
cases  serves  as  a  protection,  the  most  probable  view  in  re- 
gard to  tlie  splendid  tmts  of  many  of  the  lowest  animals 
seems  to  be  that  their  colors  are  the  direct  result  either 
of  the  clicmical  nature  or  the  minute  structure  of  their 
tissues,  independently  of  any  benefit  thus  derived.  Hard- 
ly any  color  is  finer  than  that  of  arterial  blood ;  but  there 
is  no  reason  to  suppose  that  the  color  of  the  blood  is  in 
itself  any  advantage ;  and  though  it  adds  to  the  beauty 
of  the  maiden's  cheek,  no  one  will  pretend  that  it  has  been 
acquired  for  this  purpose.  So  again  with  many  animals, 
especially  the  lower  ones,  the  bile  is  richly  colored ;  thus 
the  extreme  beauty  of  the  Eoliclre  (naked  sea-slugs)  is 
chiefly  due,  as  I  am  informed  by  Mr.  Hancock,  to  the 
biliary  glands  seen  through  the  translucent  integuments ; 
this  beauty  being  probably  of  no  service  to  these  annuals. 
The  tints  of  the  decaying  leaves  in  an  American  forest  are 
described  by  every  one  as  gorgeous ;  yet  no  one  supposes 
that  these  tints  are  of  the  least  advantage  to  the  trees. 
Bearing  in  mind  how  many  substances  closely  analogous 
to  natural  organic  compounds  have  been  recently  foimed 
by  chemists,  and  which  exhibit  the  most  splendid  colors, 
it  woidd  have  been  a  strange  fact  if  substances  similarly 
colored  had  not  often  originated,  independently  of  any 
useful  end  being  thus  gained,  in  the  complex  laboratory 
of  living  organisms.  » 

Tlie  suh-kingdoni  of  the  Mollusca. — Throughout  this 
great  division  (taken  in  its  largest  acceptation)  of  the 
animal  kingdom,  secondary  sexual  characters,  such  as  we 


Chap.  IX.]  MOLLUSKS.  315 

are  here  considering,  never,  as  far  as  I  can  discover,  occur, 
JNor  could  they  be  expected  in  the  three  lowest  classes, 
namely,  in  the  Ascidians,  Polyzoa,  and  Brachiopods  (con- 
stituting the  Molluscoida  of  Huxley),  for  most  of  these 
animals  are  permanently  affixed  to  a  support  or  have  their 
sexes  united  in  the  same  individual.  In  the  Lamellibran- 
chiata,  or  biA^alve  shells,  hermaphroditism  is  not  rare.  In 
the  next  higher  class  of  the  Gasteropoda,  or  marine  uni- 
valve shells,  the  sexes  are  either  united  or  separate.  But 
in  this  latter  case  the  males  never  possess  special  organs 
for  finding,  securing,  or  charming  the  females,  or  for  fight- 
ing with  other  males.  The  sole  external  diflerence  be- 
tween the  sexes  consists,  as  I  am  informed  by  Mr.  Gwyn 
Jeffreys,  in  the  shell  sometimes  differing  a  little  in  form; 
for  instance,  the  shell  of  the  male  periwinkle  {Littorina 
littorea)  is  narrower  and  has  a  more  elongated  spire  than 
that  of  the  female.  But  differences  of  this  nature,  it  may 
be  presumed,  are  directly  connected  with  the  act  of  repro- 
duction or  with  the  development  of  the  ova. 

The  Gasteropoda,  though  capable  of  locomotion  and 
furnished  with  imperfect  eyes,  do  not  ajopear  to  be  en- 
dowed with  sufiicient  mental  powers  for  the  members  of 
the  same  sex  to  struggle  together  in  rivalry,  and  thus  to 
acquire  secondary  sexual  characters.  Nevertheless  with 
the  pulmoniferous  gasteropods,  or  land-shells,  the  pairing 
is  preceded  by  courtshi]) ;  for  these  animals,  though  her- 
maphrodites, are  compelled  by  their  structure  to  pair  to- 
gether. Agassiz  remarks,^  "  Quiconque  a  eu  I'occasion 
d'observer  les  amours  des  limagons,  ne  saurait  raettre  en 
doute  la  seduction  deployee  dans  les  mouvements  et  les 
allures  qui  preparent  et  accomplissent  lo  double  embrasse- 
ment  de  ces  hermaphrodites,"  These  animals  appear  also 
susceptible  of  some  degree  of  permanent  attachment :  an 
accurate  observer,  Mr.  Lonsdale,  informs  me  that  he  placed 
'  •  De  TEspice  ct  dc  la  Class.'  etc.,  18G9,  p.  100. 


316  SEXUAL  SELECTION.  [Part  U. 

a  pair  of  land-shells  {Helix  jjomatia),  one  of  which  was 
weakly,  into  a  small  and  ill-provided  garden.  After  a 
short  time  the  strong  and  healthy  individual  disappeared, 
and  was  traced  by  its  track  of  slime  over  a  wall  into  an 
adjoining  well-stocked  garden.  Mr,  Lonsdale  concluded 
that  it  had  deserted  its  sickly  mate ;  but  after  an  absence 
of  twenty-four  hoiirs  it  returned,  and  apparently  commu- 
nicated the  result  of  its  successful  exploration,  for  both 
then  started  along  the  same  track  and  disappeared  over 
the  wall. 

Even  in  the  highest  class  of  the  Mollusca,  namely,  the 
Cephalopoda  or  cuttle-fishes,  in  which  the  sexes  are  sepa- 
rate, secondary  sexual  characters  of  the  kind  which  we 
are  here  considering  do  not,  as  far  as  I  can  discover,  oc- 
cur. This  is  a  surprising  circumstance,  as  these  animals 
jjossess  highly-develoj^ed  sense-organs  and  have  consider- 
able mental  powers,  as  will  be  admitted  by  every  one 
who  has  watched  their  artful  endeavors  to  escape  from  an 
enemy.'  Certain  Cephaloi^oda,  however,  are  characterized 
by  one  extraordinary  sexual  character,  namely,  that  the 
male  element  collects  ■v\'ithin  one  of  the  arms  or  tentacles, 
which  is  then  cast  oiF,  and,  clinging  by  its  sucking-disks 
to  the  female,  lives  for  a  time  an  independent  life.  So 
completely  does  the  cast-off  arm  resemble  a  separate  ani- 
mal, that  it  was  described  by  Cuvier  as  a  i')arasitic  worm 
under  the  name  of  Hectocotyle.  But  this  marvellous 
structure  may  be  classed  as  a  primary  rather  than  as  a 
secondary  sexual  character. 

Although  with  the  Mollusca  sexual  selection  does  not 
seem  to  have  come  into  play,  yet  many  xmivalvc  and 
bivalve  shells,  such  as  volutes,  cones,  scallojis,  etc.,  are 
beautifully  colored  and  shaped.  The  colors  do  not  appear 
in  most  cases  to  be  of  any  use  as  a  protection  ;  tliey  are 

-  Sec,  for  instance,  the  account  ^Yhich  I  have  given  in  my  '  Journal 
of  Researches,'  1845,  p.  7. 


CiiAP.  IX.J  MOLLUSKS  AND   ANXELIDS.  317 

probably  the  direct  result,  as  in  the  lowest  classes,  of  tlie 
nature  of  the  tissues  ;  the  patterns  and  the  sculpture  of  the 
shell  depending  on  its  manner  of  growth.  The  amount 
of  light  seems  to  a  certain  extent  to  be  influential ;  for 
although,  as  repeatedly  stated  by  Mr.  Gwyn  Jeflreys, 
the  shells  of  some  species  living  at  a  profound  depth 
are  brightly  colored,  yet  we  generally  see  the  lower  sur- 
faces and  the  parts  covered  by  the  mantle  less  highly 
colored  than  the  upper  and  exposed  surfaces.'  In  some 
cases,  as  Avith  shells  living  among  corals  or  brightly-tinted 
sea-weeds,  the  bright  colors  may  serve  as  a  protection. 
But  many  of  the  niidibranch  mollusca,  or  sea-slugs,  are 
as  beautifully  colored  as  any  shells,  as  may  be  seen  in 
Messrs.  Alder  and  Hancock's  magnificent  work ;  and  from 
information  kindly  given  me  by  Mr.  Hancock,  it  is  ex- 
tremely doubtful  whether  these  colors  visually  serve  as  a 
protection.  With  some  species  this  may  be  the  case,  as 
with  one  which  lives  on  the  green  leaves  of  algse,  and  is 
itself  bright  green.  But  many  brightly-colored,  white  or 
otherwise  conspicuous  species,  do  not  seek  concealment ; 
while  again  some  equally  conspicuous  species,  as  well  as 
other  dull-colored  kinds,  live  under  stones  and  in  dark  re- 
cesses. So  that,  with  these  niidibranch  mollusks,  color 
apparently  does  not  stand  in  any  close  relation  to  the  na- 
ture of  the  places  which  they  inhabit. 

These  naked  sea-slugs  are  hermaphrodites,  yet  they 
pair  together,  as  do  land-snails,  many  of  which  have  ex- 
tremely pretty  shells.  It  is  conceivable  that  two  hermaph- 
rodites, attracted  by  each  other's  greater  beauty,  might 
unite  and  leave  offspring  which  would  inherit  their  par- 
ents' greater  beauty.      But   with   such   lowly-organized 

^  I  have  given  ('  Gcolog.  Observations  on  Yolcanic  Islands,'  18-14,  p. 
C3)  a  curious  instance  of  the  influence  of  light  on  the  colors  of  a  fron- 
descent  incrustation,  deposited  by  the  surf  on  the  coast-rocks  of  Ascen- 
BioD,  and  formed  by  the  solution  of  triturated  sea-shells. 


318  SEXUAL  SELECTION.  [Part  IL 

creatures  this  is  extremely  improbable.  Nor  is  it  at  all 
obvious  liow  the  offspring  from  the  more  beautiful  pairs 
of  hermaphrodites  would  have  any  advantage,  so  as  to  in- 
crease in  numbers,  over  the  offspring  of  the  less  beautiful, 
unless  indeed  vigor  and  beauty  generally  coincided.  We 
have  not  here  a  number  of  males  becoming  mature  before 
the  females,  and  the  more  beautiful  ones  selected  by  the 
more  vigorous  females.  If,  indeed,  brilliant  colors  were 
beneficial  to  an  hermaphrodite  animal  in  relation  to  its 
genei-al  habits  of  life,  the  more  brightly-tinted  individuals 
Avould  succeed  best  and  would  increase  in  number ;  but 
this  would  be  a  case  of  natural  and  not  of  sexual  selection. 

Suh-Mngdom  of  the  Yei'mes  or  Ammlosa :  Class,  An- 
nelida {or  Sea-worins). — In  this  class,  although  the  sexes 
(when  separate)  sometimes  differ  from  each  other  in  char- 
acters of  such  importance  that  they  have  been  placed  un- 
der distinct  genera  or  even  families,  yet  the  differences  do 
not  seem  of  the  kind  which  can  be  safely  attributed  to 
sexual  selection.  These  animals,  like  those  in  the  preced- 
ing classes,  apj^arently  stand  too  low  in  the  scale  for  the 
individuals  of  either  sex  to  exert  any  choice  in  selecting 
a  partner,  or  for  the  individuals  of  the  same  sex  to  strug- 
gle together  in  rivalry. 

Suh-Jcingdom  of  the  Arthropoda :  Class,  Crustacea. — 
In  this  great  class  we  first  meet  with  undoubted  second- 
ary sexual  characters,  often  developed  in  a  remarkable 
manner.  Unfortunately,  the  habits  of  crustaceans  are 
very  imjierfectly  known,  and  we  cannot  explain  the  uses 
of  many  structures  peculiar  to  one -sex.  "With  the  lower 
parasitic  species  the  males  are  of  small  size,  and  they 
alone  arc  furnished  with  perfect  swimming-legs,  antenna; 
and  sense-organs  ;  the  females  being  destitute  of  these  or- 
gans, with  their  bodies  often  consisting  of  a  mere   dis- 


Chap.  IX.]  CRUSTACEANS.  319 

torted  mass.  But  these  extraordinary  dilFerences  between 
the  two  sexes  are  no  doubt  related  to  their  widely-differ- 
ent habits  of  life,  and  consequently  do  not  concern  us. 
In  various  crustaceans,  belonging  to  distinct  families,  the 
anterior  antennae  are  furnished  with  peculiar  thread-like 
bodies,  which  are  believed  to  act  as  smelling-organs,  and 
these  are  much  more  numerous  in  the  males  than  in  the 
females.  As  the  males,  without  any  unusual  development 
of  their  olfactory  organs,  would  almost  certainly  be  able 
sooner  or  later  to  find  the  females,  the  increased  number 
of  the  smelling  -  threads  has  probably  been  acquired 
thi-ough  sexual  selection,  by  the  better  provided  males 
having  been  the  most  successful  in  finding  partners  and 
in  leaving  offsj^ring.  Fritz  Miiller  has  described  a  re- 
markable dimorphic  species  of  Tanais,  in  which  the  male 
is  rej^resented  by  two  distinct  forms,  never  graduating 
into  each  other.  In  the  one  form  the  male  is  furnished 
with  more  numerous  smelling-threads,  and  in  the  other 
form  with  more  powerful  and  more  elongated  chelae  or 
pincers  which  serve  to  hold  the  female.  Fritz  Miiller  sug- 
gests that  these  diiferences  between  the  two  male  forms 
of  the  same  species  must  have  originated  in  certain  indi- 
Adduals  having  varied  in  the  num.ber  of  the  smellinsf- 
threads,  while  otlier  individuals  varied  in  the  shape  and 
size  of  their  chelre ;  so  that  of  the  former,  those  which 
were  best  able  to  find  the  female,  and  of  the  latter,  those 
which  were  best  able  to  hold  her  ^vhen  found,  have  left 
the  greater  number  of  progeny  to  inherit  their  respecti^•e 
advantages.* 

In  some  of  the  lower  crustaceans,  the  right-hand  an- 
terior antenna  of   the  male  differs   greatly  in   structure 

*' Facts  and  Arguments  for  Darwin,'  English  translat.  1869,  p.  20. 
See  the  previous  discussion  on  the  olfactory  threads.  Sars  has  described 
a  somewhat  analogous  case  (as  quoted  in  'Nature,'  1870,  p.  455)  in  a 
Norwegian  crustacean,  the  Foiiioporehi  a^nh. 


320 


SEXUAL  SELECTION. 


[Part  II. 


from  the  left-hand  one,  the  latter  resembling  in  its  sim- 
ple tapering  joints  the  antenna;  of  the  female.    In  the  male 
the    modified    antenna   is   cither 

n 

swollen  in  the  middle  or  angu- 
larly bent,  or  converted  (fig.  3) 
into  an  elegant,  and  sometimes 
■wonderfully  complex,  prehensile 
organ. '^  It  serves,  as  I  hear  from 
Sir  J.  Lubbock,  to  hold  the  fe- 
male, and  for  this  same  purpose 
one  of  the  two  posterior  legs  [b) 
on  the  same  side  of  the  body  is 
converted  into  a  forceps.  In  an- 
other family  the  inferior  or  pos- 
terior antenna)  are  "  curiously  zig- 
zagged "  in  the  males  alone. 

In  the  higher  crustaceans  the 
anterior  legs  form  a  pair  of  chelae 
or  pincers,  and  these  are  gener- 
ally larger  in  the  male  than  in 
the  female.  In  many  species  the 
chelffi  on  the  opposite  sides  of  the 
body  are  of  unequal  size,  the  right- 
hand  one  being,  as  I  am  informed 
by  Mr.  D.  Spence  Bate,  generally, 
though  not  invariably,  the  largest. 
This  inequality  is  often  much  greater  in  the  male  than  in 
the  female.  The  two  chcloD  also  often  diflfer  in  structure 
(figs.  4  and  6),  the  sriialler  one  resembling  those  of  the  fe- 
male.   What  advantage  is  gained  by  their  inequality  in  size 


Fig.  3.— Labirlocera    Darwinii 
(from  Lubbock). 

a.  Part  of  ric^ht-hand  anterior 

nnteniia  of  male,  forming  a 
prelionsilc  organ. 

b.  Postorior  pair  of  the  thoracic 

logs  of  male. 

c.  Ditto  of  female. 


5  Sec  Sir  J.  Lubbock  in  'Annals,  and  Mas-  of  Nat.  Hirt.'  vol.  xi.  1853, 
pis.  i.  and  x. ;  and  vol.  xii.  (18o3)  pi.  vii.  Sec  also  Lubbock  in  '  Transact. 
Ent.  Soc'  vol.  iv.  new  series,  1856-1858,  p.  8.  With  respect  to  the  zig- 
zagged antcnnjc  mentioned  below,  sec  Fritz  Miiller,  '  Facts  and  Argu- 
ments for  Darwin,'  1850,  p.  40,  foot-note. 


Chap.  IX.] 


CRUSTACEANS. 


321 


on  the  opposite  sides  of  the  body,  and  by  the  inequality  be- 
ing much  greater  in  the  male  than  in  the  female ;  and  why, 


Fig.  4. — Anterior  part  of  body  of  Caliianassa  (from  Milne-Edwards),  showing 
the  unequal  and  differently-constructed  right  and  left-hand  chelse  of  the  male. 

N.B.— The  artist  by  mistake  has  reversed  the  drawing,  and  made  the  left- 
hand  chela  the  largest. 


Fig.  6. 

Fig.  5.— Second  log  of  male  Orchestia  Tucuratinga  (from  Fritz  Miiller). 
Fig.  C— Ditto  of  female. 


when  they  are  of  equal  size,  both  arc  often  much  larger 
in  the  male  than  in  the  female,  is  not  known.  The  chelaa 
are  sometimes  of  such  length  and  size  that  they  cannot 
possibly  be  used,  as  I  hear  from  Mr.  Spence  Bate,  for  car- 
rjnng  food  to  the  mouth.  In  the  males  of  certain  fresh- 
water prawns  (Palosmon)  the  right  leg  is  actually  longer 


32^  SEXUAL   SELECTION.  [Part  IL 

than  the  whole  body."  It  is  probable  that  the  great  size 
of  one  leg  with  its  chela;  may  aid  the  male  in  fighting 
with  his  rivals  ;  but  this  use  will  not  account  for  their  in- 
equality in  the  female  on  the  opposite  sides  of  the  body. 
In  Gelasimus,  according  to  a  statement  quoted  by  Milne- 
Edwards,'  the  male  and  female  live  in  the  same  burrow, 
which  is  worth  notice,  as  showing  that  they  pair,  and  the 
male  closes  the  mouth  of  the  burrow  with  one  of  its  chela?, 
which  is  enormously  developed ;  so  that  here  it  indirectly 
serves  as  a  means  of  defence.  Their  main  use,  however, 
probably  is  to  seize  and  to  secure  the  female,  and  this  in 
some  instances,  as  with  Gammarus,  is  known  to  be  the 
case.  The  sexes,  however,  of  the  common  shore-ci-ab 
( Carcinus  nicenas),  as  Mr.  Spence  Bate  informs  me,  unite 
directly  after  the  female  has  moulted  her  hard  shell,  and 
when  she  is  so  soft  that  she  would  be  injured  if  seized  by 
the  strong  pincers  of  the  male ;  but  as  she  is  caught  and 
carried  about  by  the  male  previously  to  the  act  of  moult- 
ing, she  could  then  be  seized  with  impunity. 

Fritz  Miiller  states  that  certain  species  of  ]\[elita  are 
distinguished  from  all  other  amphipods  by  the  females 
having  "  the  coxal  lamellae  of  the  penultimate  pair  of  feet 
produced  into  hook-like  processes,  of  which  the  males  lay 
hold  with  the  hands  of  the  first  pair."  The  development 
of  these  hook-like  processes  probably  resulted  from  those 
females  which  were  the  most  securely  held  during  the  act 
of  reproduction  having  left  the  largest  number  of  off- 
spring. Another  Brazilian  amphipod  {Orchestia  Dar- 
winii,  fig.  1)  is  described,  by  Fritz  Miiller,  as  presenting  a 
case  of  dimorphism,  like  that  of  Tanais ;  for  there  are  two 

*  See  a  paper  by  Mr.  C.  Spence  Bate,  witli  figures,  in  '  Proc.  Zoolog. 
Soc'  1868,  p.  363;  and  on  the  nomenclature  of  the  genus,  ibid.  p.  585. 
I  am  greatly  indebted  to  Mr.  Spence  Bate  for  nearly  all  the  above  state- 
ments with  respect  to  the  chela;  of  the  higher  crustaceans. 

'  '  Hist.  Xat.  des  Crust.'  torn.  ii.  1837,  p.  50. 


Chap.  IX.]  CRUSTACEANS.  323 

male  forms,  wliicli  difter  in  the  structure  of  their  chelae/ 
As  chete  of  either  shape  would  certainly  have  sufficed  to 
hold  the  female,  for  both  are  now  used  for  this  purpose, 
the  two  male  forms  jDrobably  originated,  by  some  having 
varied  in  one  manner  and  some  in  another ;  both  forms 
liaving  derived  certain  special  but  nearly  equal  advan- 
tages, from  their  differently-shaped  organs. 

It  is  not  known  that  male  crustaceans  fight  together 
for  the  possession  of  the  females,  but  this  is  probable ;  for 
with  most  animals  when  the  male  is  larger  than  the  female, 
he  seems  to  have  acquired  his  greater  size  by  having  con- 
quered during  many  generations  other  males.  N'ow,  Mr. 
Spence  Bate  informs  me  that  in  most  of  the  crustacean 
orders,  especially  in  the  highest  or  the  Brachyura,  the 
male  is  larger  than  the  female ;  the  parasitic  genera,  how- 
ever, in  which  the  sexes  follow  different  habits  of  life,  and 
most  of  the  Entomostraca  must  be  excepted.  The  chelae 
of  many  crustaceans  are  weapons  well  adapted  for  fight- 
ing. Thus  a  Devil-crab  {Portunus  puher)  was  seen  by  a 
son  of  Mr.  Bate  fighting  with  a  Carcinus  mcenas,  and  the 
latter  was  soon  throv\^n  on  its  back,  and  had  every  limb 
torn  from  its  body.  When  several  males  of  a  Brazilian 
Gelasimus,  a  species  furnished  with  immense  pincers,  were 
placed  together  by  Fritz  Miiller  in  a  glass  vessel,  they 
mutilated  and  killed  each  other.  Mr.  Bate  put  a  large 
male  Carcinus  mcenas  into  a  pan  of  water,  inhabited  by 
a  female  paired  with  a  smaller  .male ;  the  latter  was  soon 
dispossessed,  but,  as  Mr.  Bate  adds,  "  if  they  fought,  the 
victory  was  a  bloodless  one,  for  I  saw  no  wounds."  This 
same  naturalist  separated  a  male  sand-skipper  (so  common 
on  our  sea-shores),  Gammarus  tnarinus,  from  its  female, 
both  of  which  were  imprisoned  in  the  same  vessel  witli 
many  individuals  of  the  same  species.  The  female,  being 
thus  divorced,  joined  her  comrades.  After  an  interval  the 
^  Fritz  Miiller,  'Facts  and  Arguments  for  Darwin,'  1869,  pp.  25-28. 


324 


SEXUAL   SELECTION. 


[Part  IL 


male  was  again  put  into  the  f;anic  vessel  and  he  then,  after 
swimming  about  for  a  time,  dashed  into  the  crowd,  and 
without  any  fighting  at  once  took  away  his  wife.     This 


Fig.  7.— Orcbeatia  Darwinii  (from  Fritz  Muller\  sliowing  the  differently-con- 
structed chela  of  the  two  male  forms. 


fact  shows  that  in  the  Amphipoda,  an  order  low  in  the 
scale,  the  males  and  females  recognize  each  other,  and  are 
mutuallv  attached. 


Chap.  IX.]  CRCSTACEAXS.  325 

The  mental  powers  of  the  Crustacea  are  probably 
higher  than  might  have  been  expected.  Any  one  who 
has  tried  to  catch  one  of  the  shore-crabs,  so  numerous  on 
many  tropical  coasts,  will  have  perceived  how  wary  and 
alert  they  are.  There  is  a  large  crab  [Birgos  latro),  found 
on  coral  islands,  which  makes  at  the  bottom  of  a  deep 
burrow  a  thick  bed  of  the  picked  fibres  of  the  cocoa-nut. 
It  feeds  on  the  fallen  fruit  of  this  tree  by  tearing  oif  the 
husk,  fibre  by  fibre ;  and  it  always  begins  at  that  end 
where  the  three  eye-like  depressions  are  situated.  It  then 
breaks  through  one  of  these  eyes  by  hammering  with  its 
heavy  front  pincers,  and,  turning  round,  extracts  the  al- 
buminous core  with  its  narrow  posterior  pincers.  But  these 
actions  are  probably  instinctive,  so  that  they  would  be 
performed  as  well  by  a  young  as  by  an  old  animal.  The 
following  case,  however,  can  hardly  be  so  considered :  A 
trustworthy  naturalist,  Mr.  Gardner,'  while  watching  a 
shore-crab  (Gelasimus)  making  its  burrow,  threw  some 
shells  toward  the  hole.  One  rolled  in,  and  three  other 
shells  remained  within  a  few  inches  of  the  mouth.  In 
about  fire  minutes  the  crab  brought  out  the  shell  which 
had  fallen  in,  and  carried  it  away  to  the  distance  of  a 
foot ;  it  then  saw  the  three  other  shells  lying  near,  and 
evidently  thinking  that  they  might  likewise  roll  in,  carried 
them  to  the  spot  where  it  had  laid  the  first.  It  would,  I 
think,  be  difticitlt  to  distinguish  this  act  from  one  per- 
formed by  man  by  the  aid  of  reason. 

With  respect  to  color  which  so  often  differs  in  the 
two  sexes  of  animals  belonging  to  the  higher  classes,  Mr. 
Spence  Bate  does  not  know  of  any  well-marked  instances 
with  our  British  crustaceans.  In  some  cases,  however, 
the  male  and  female  differ  somewhat  in  tint,  but  Mr.  Bate 

'  'Travels  in  the  Interior  of  Brazil,'  184G,  p.  111.  I  have  given,  in 
my  '  Journal  of  Researches,'  p.  463,  an  account  of  the  habits  of  the 
Birgos. 


320  SEXUAL  SELECTION.  [Pai>.t  II, 

thinks  not  more  than  may  be  accounted  for  by  their  dif- 
ferent habits  of  life,  such  as  by  the  male  wandering 
more  about  and  being  thus  more  exposed  to  the  light. 
In  a  curious  Bornean  crab,  which  inhabits  sponges.  Mi*. 
Bate  could  always  distinguish  the  sexes  by  the  male  not 
having  the  ejndermis  so  much  rubbed  off.  Dr.  Power 
tried  to  distinguish  by  color  the  sexes  of  the  species 
which  inhabit  the  I\rauritius,  but  always  failed,  except 
with  one  sj^ecies  of  Squilla,  proably  the  JS.  stylifera^  the 
male  of  which  is  described  as  being  "  of  a  beautiful  blu- 
ish-green," with  some  of  the  appendages  cherry-red,  while 
the  female  is  clouded  with  brown  and  gray,  "  with  the 
red  about  her  much  less  vivid  than  in  the  male.""  In  this 
case,  we  may  suspect  the  agency  of  sexual  selection.  With 
Saphirina  (an  oceanic  genus  of  Entomostraca,  and  there- 
fore low  in  the  scale)  the  males  are  furnished  with  minute 
shields  or  cell-like  bodies,  which  exhibit  beautiful  chan- 
ging colors ;  these  being  absent  in  the  females,  and  in  the 
case  of  one  species  in  both  sexes."  It  Avould,  however,  be 
extremely  rash  to  conclude  that  these  curious  organs  serve 
merely  to  attract  the  females.  In  the  female  of  a  Brazil- 
ian species  of  Gelasimus,  the  v.hole  body,  as  I  am  informed 
by  Fritz  Mtiller,  is  of  a  nearly  uniform  grayish-brown. 
In  the  male  the  posterior  part  of  the  cephalo-thorax  is 
pure  white,  with  the  anterior  part  of  a  rich  green,  shading 
into  dark  brown ;  and  it  is  remarkable  that  these  colors 
are  liable  to  change  in  the  course  of  a  few  minutes — the 
white  becoming  dirty-gray  or  even  black,  the  green  "  los- 
ing much  of  its  brilliancy."  The  males  apparently  are 
much  more  numerous  than  the  females.  It  deserves  es- 
pecial notice  that  they  do  not  acquire  their  bright  colors 
until  they  become  mature.     They  differ  also  from  the  fe- 

'"  Mr.  Ch.  Frascr,  in  'Proc.  Zoolog.  Soc'  18G9,  p.  3.     I  am  indebted 
to  Mr.  Bate  for  the  statement  from  Dr.  Power. 

"  Clans,  'Die  freilebenden  roi)epoden,'  1863,  ?.  35. 


Chap.  IX.]  SPIDERS.  327 

males  in  tho  larger  size  of  their  Cheloe,  In  some  species 
of  the  genus,  probably  in  all,  the  sexes  pair  and  inhabit 
the  same  burrow.  They  are  also,  as  we  have  seen,  highly- 
intelligent  animals.  From  the  various  considerations  it 
seems  highly  probable  that  the  male  in  this  species  has  be- 
come gayly  ornamented  in  order  to  attract  or  excite  the 
female. 

It  has  just  been  stated  that  the  male  Gelasimus  does 
not  acquire  his  conspicuous  colors  until  mature  and  nearly 
ready  to  breed.  This  seems  the  general  rule  in  the  whole 
class  with  the  many  remarkable  differences  in  structure 
between  the  two  sexes.  We  shall  hereafter  find  the  same 
law  prevailing  throughout  the  great  sub-kingdom  of  the 
Vertebrata,  and  in  all  cases  it  is  eminently  distinctive  of 
characters  which  have  been  acquired  through  sexual  se- 
lection. Fritz  Miiller  '"  gives  some  striking  instances  of 
this  law ;  thus  the  male  sand-hopper  (Orchestia)  does  not 
acquire  his  large  claspers,  which  are  very  differently  con- 
structed from  those  of  the  female,  unttl  nearly  full  grown ; 
while  young  his  claspers  resemble  those  of  the  female. 
Thus,  again,  the  male  Brachyscelus  possesses,  like  all  other 
araphipods,  a  pair  of  posterior  antennte  ;  the  female,  and 
this  is  a  most  extraordinary  circumstance,  is  destitute  of 
them,  and  so  is  the  male  as  long  as  he  remains  immature. 

Class,  Araehnida  (Spiders). — The  males  are  often 
darker,  but  sometimes  lighter  than  the  females,  as  may  be 
seen  in  Mr.  Blackwall's  magnificent  work."  In  some  spe- 
cies the  sexes  differ  conspicuously  from  each  other  in  col- 
or; thus  the  female  of  Sparassus  smaragdulus  is  dullish 
green,  while  the  adult  male  has  the  abdomen  of  a  fine 
yellow,  with  three  longitudinal  stripes  of  rich  red.     In 

'-  '  Facts  and  Arguments,'  etc.,  p.  79. 

'3  '  A  History  of  the  Spiders  of  Great  Britain,'  1861-1864.  For  the 
following  facts,  see  pp.  102,  77,  88. 


328  "  SEXUAL  SELECTION.  [Part  IL 

some  species  of  Thomisirs  the  two  sexes  closely  resemble 
each  other ;  in  others  they  difier  much ;  thus  in  T.  citreus 
the  logs  and  body  of  the  female  are  pale  yellow  or  green, 
"while  the  front  legs  of  the  male  are  reddish-brov/n :  in  T. 
floricolens^  the  legs  of  the  female  are  pale-green,  those  of 
the  male  being  ringed  in  a  conspicuous  manner  with  vari- 
ous tints.  Numerous  analogous  cases  could  be  given  in  the 
genera  Epeira,  Nephila,  Philodromus,  Theridion,  Liny- 
phia,  etc.  It  is  often  difficult  to  say  which  of  the  two 
sexes  departs  most  from  the  ordinary  coloration  of  the 
genus  to  which  the  species  belong ;  but  Mi*.  Blackwall 
thinks  that,  as  a  general  rule,  it  is  the  male.  Both  sexes 
while  young,  as  I  am  infox"med  by  the  same  author,  usu- 
ally resemble  each  other ;  and  both  often  undergo  great 
changes  in  color  during  their  successive  moults  before  ar- 
riving at  maturity.  In  other  cases  the  male  alone  appears 
to  change  color.  Thus  the  male  of  the  above-mentioned 
brightly-colored  Sparassus  at  first  resembles  the  female 
and  acquires  his  peculiar  tints  only  when  nearly  adult. 
Spiders  are  possessed  of  acute  senses,  and  exhibit  much 
intelligence.  The  females  often  show,  as  is  well  known, 
the  strongest  affection  for  their  eggs,  which  tliey  carry 
about  enveloped  in  a  silken  web.  On  the  whole,  it  ap- 
jDoars  pi'obable  that  well-marked  differences  in  color  be- 
tween the  sexes  have  generally  i*esulted  from  sexual  se- 
lection, either  on  the  male  or  female  side.  But  doubts 
may  be  enteitained  on  this  head  from  the  extreme  varia- 
bility in  color  of  some  species,  for  instance,  of  Theridion 
Uneatum^  the  sexes  of  which  differ  when  adult ;  this  great 
variability  indicates  that  their  colors  have  not  been  sub- 
jected to  any  form  of  selection. 

Mr.  Blackwall  does  not  remember  to  have  seen  the 
males  of  any  species  fighting  together  for  tlie  possession 
of  the  female.  Nor,  judging  from  analogy,  is  this  proba- 
ble ;  for  the  males  are  generally  much  smaller  than  the 


Chap.  IX.]  .  SPIDERS.  329 

females,  sometimes  to  an  extraordinary  degree.**  Had 
the  males  been  in  the  habit  of  fighting  together,  they 
would,  it  is  probable,  have  gradually  acquired  greater 
size  and  strength.  Mr.  Blackwall  has  sometimes  seen 
two  or  more  males  on  the  same  web  with  a  single  female ; 
but  their  courtship  is  too  tedious  and  prolonged  an  alFair 
to  be  easily  observed.  The  male  is  extremely  cautious  in 
making  his  advances,  as  the  female  carries  her  coyness  to 
a  dangerous  pitch.  De  Geer  saw  a  male  that  "  in  the 
midst  of  his  preparatory  caresses  was  seized  by  the  object 
of  his  attractions,  enveloped  by  her  in  a  web  and  then  de- 
voured, a  sight  which,  as  he  adds,  filled  him  with  horror 
and  indignation."  " 

Westring  has  made  the  interesting  discovery  that  the 
males  of  several  species  of  Thei-idion  '°  have  the  power  of 
making  a  stridulating  sound  (like  that  made  by  many 
beetles  and  other  insects,  but  feebler),  while  the  females 
are  quite  mute.  The  apparatus  consists  of  a  serrated  ridge 
at  the  base  of  the  abdomen,  against  which  the  hard  hinder 
part  of  the  thorax  is  rubbed ;  and  of  this  structure  not  a 
trace  could  be  detected  in  the  females.  From  the  analogy 
of  the  Orthoptera  and  Homoptera,  to  be  described  in  the 
next  chapter,  we  may  feel  almost  sure  that  the  stridulation 
serves,  as  Westring  remarks,  either  to  call  or  to  excite 

'■*  Aug.  Vinson  ('  Araneides  des  lies  de  la  Reunion,'  pi.  vi.  figs.  1  and 
2)  gives  a  good  instance  of  the  small  size  of  the  male  Epeira  nigra.  In 
this  species,  as  I  may  add,  the  male  is  testaceous  and  the  female  black 
with  legs  banded  with  red.  Other  even  more  striking  cases  of  inequality 
in  size  between  the  sexes  have  been  recorded  ('  Quarterly  Journal  of 
Science,'  1868,  July,  p.  429);  but  I  have  not  seen  the  original  accoimts. 

'5  Kirby  and  Spence,  '  Introduction  to  Entomology,'  vol.  i.  1818,  p. 
280. 

'«  Theridion  (Asagena,  Sund.)  serratipes,  4-punctatum  et  guttatum ; 
see  Westring,  in   Kroyer,  'Naturhist.  Tidskrift,'  vol.  iv.  1842-1843,  p. 
349  ;  and  vol.  ii.  1846-1849,  p.  342.     See,  also,  for  other  species,  '  Ara- 
neae  Svecicae,'  p.  184. 
15 


330  SEXUAL  SELECTION.  [Part  II. 

the  female ;  and  tliis  is  the  first  case  in  tlie  ascending  scale 
of  the  animal  kingdom,  known  to  me,  of  sounds  emitted 
for  this  purpose. 

Class,  Myriapoda. — In  neither  of  the  two  orders  in 
this  class,  including  the  millipedes  and  centipedes,  can  I 
find  any  well-marked  instances  of  sexual  difierences  such 
as  more  particularly  concern  us.  In  Gloyneris  limbata, 
however,  and  perhaps  in  some  few  other  species,  the  males 
differ  slightly  in  color  from  the  females ;  but  this  Glomeris 
is  a  highly-variable  sijecies.  In  the  males  of  the  Diplo- 
poda,  the  legs  belonging  to  one  of  the  anterior  segments 
of  the  body,  or  to  the  posterior  segment,  are  modified  into 
prehensile  hooks  which  serve  to  secure  the  female.  In 
some  species  of  lulus  the  tarsi  of  the  male  are  furnished 
with  membranous  suckers  for  the  same  purpose.  It  is  a 
much  more  unusual  circumstance,  as  Ave  shall  see  when  we 
treat  of  Insects,  that  it  is  the  female  in  Lithobius  which  is 
furnished  with  prehensile  appendages  at  the  extremity  of 
the  body  for  holding  the  male." 

"  Walckenaer  et  P.  Gcrvais,  '  Hist,  Nat.  des  Insectes  ;  Apteres,  tona. 
iv.  18^7,  pp.  lY,  19,  08. 


Chap.  X.]  INSECTS.  331 


CHAPTER  X. 

SECONDAET   SEXUAL   CHARACTERS    OF   INSECTS. 

Diversified  Structures  possessed  by  the  Males  for  seizing  the  Females. — 
Difi'erences  between  the  Sexes,  of  -which  the  Meaning  is  not  under- 
stood.— Difference  in  Size  between  the  Sexes. — Thysanura. — Diptera. 
— Hemiptera. — Homoptera,  Musical  Powers  possessed  by  the  Males 
alone. — Orthoptera,  Musical  Instruments  of  the  Males,  much  diversi- 
fied in  Structure ;  Pugnacity ;  Colors. — Neuroptera,  Sexual  Differences 
in  Color. — Hymenoptera,  Pugnacity  and  Colors. — Coleoptera,- Colors  ; 
furnished  with  Great  Horns,  apparently  as  an  Ornament;  Battles; 
Stridulating  Organs  generally  common  to  Both  Sexes. 

In  the  immense  class  of  insects  the  sexes  sometimes 
differ  in  their  organs  for  locomotion,  and  often  in  their 
sense-organs,  as  in  the  pectinated  and  beautifully  plumose 
antennae  of  the  males  of  many  species.  In  one  of  the 
Ephemerae,  namely  Chloeon,  the  male  has  great  pillared 
eyes,  of  which  the  female  is  entirely  destitute.*  The  ocelli 
are  absent  in  the  females  of  certain  other  insects,  as  in  the 
Mutillidoe,  ■which  are  likewise  destitute  of  wings.  But  we 
are  chiefly  concerned  with  structures  by  which  one  male  is 
enabled  to  conquer  another,  either  in  battle  or  courtship, 
through  his  strength,  pugnacity,  ornaments,  or  music. 
The  innumerable  contrivances,  therefore,  by  which  the 
male  is  able  to  seize  tlie  female,  may  be  briefly  passed 
over.     Besides  the  complex  structures  at  the  apex  of  the 

^  Sir  J.  Lubbock,  '  Transact.  Linnean  Soc'  vol.  xxv.  1866,  p.  484. 
With  I'espect  to  the  Mutillidae  see  Westwood,  '  Mod.  Class,  of  Insects,' 
vol.  ii.  p.  213. 


332  SEXUAL  SFXECTION.  [Pakt  II. 

abdomen,  which  ouglit  perliaps  to  be  ranked  as  primary 
organs,'  "it  is  astonishing,"  as  Mr.  B.  D.  Walsh'  has  re- 
marked, "how  many  difterent  organs  are  worked  in  by 
Nature,  for  the  seemingly  insignificant  object  of  enabling 
the  male  to  grasp  the  female  firmly."  The  mandibles  or 
jaws  are  sometimes  used  for  this  purpose;  thus  the  male 
Corydalis  cornutus  (a  neuropterous  insect  in  some  degree 
allied  to  the  Dragon-fiies,  etc.)  has  immense  curved  jaws, 
many  times  longer  than  those  of  the  fcmiile ;  and  they  are 
smooth  instead  of  being  toothed,  by  which  means  he  is 
enabled  to  seize  her  without  injury.*  One  of  the  stag- 
beetles  of  North  America  (JJiccanus  elaj^hus)  uses  his  jaws, 
which  are  m\ich  larger  than  those  of  the  female,  for  the 
same  purpose,  but  probably  likewise  for  fighting.  In  one 
of  the  sand-wasps  (Ammophila)  the  jaws  in  the  two  sexes 
are  closely  alike,  but  are  used  for  widely-different  pur- 
poses ;  the  males,  as  Prof.  Westwood  observes,  "  are  ex- 
ceedingly ardent,  seizing  their  partners  round  the  neck 
with   their  sickle-shaped  jaws;"'   while   the  females  use 

*  These  organs  in  the  male  often  differ  in  closely-allied  species,  and 
afford  excellent  specific  characters.  But  their  importance  under  a  func- 
tional point  of  view,  as  Mr.  R.  MacLachlan  has  remarked  to  me,  has 
probably  been  overrated.  It  has  been  suggested,  that  slight  differences 
in  these  organs  would  suffice  to  prevent  the  intercrossing  of  well-marked 
varieties  or  incipient  species,  and  would  thus  aid  in  their  development. 
That  this  can  hardly  be  the.  case,  we  may  infer  from  the  many  recorded 
cases  (see,  for  instance,  Bronn,  'Geschichte  dcr  \atur,' B.  ii.  1843,  s. 
164;  and  Westwood,  'Transact.  Ent.  Soc' vol.  iii.  1842,  p.  195)ofdis. 
tinct  species  having  been  observed  in  union.  Mr.  MacLachlan  informs 
nie  (vide  'Stett.  Ent.  Zeitung,'  1867,  s.  155)  that  when  several  species  of 
Phryganidae,  which  present  strongly-pronounced  differences  of  this  kind, 
were  confined  together  by  Dr.  Aug.  Meyer,  thei/  coupled,  and  one  pair 
produced  fertile  ova. 

3  '  The  Practical  Entomologist,'  Philadelphia,  vol.  ii.  May,  1867,  p.  88. 
^  Mr.  Walsh,  ibid.  p.  107. 

*  '  Modern  Classification  of  Insects,'  vol.  ii.  1840,  pp.  206,  205.  Mr. 
Walsh,  who  called  my  attention  to  this  double  use  of  the  jaws,  says  that 
he  has  repeatedly  observed  this  fact. 


Chap.  X.] 


INSECTS. 


333 


these  organs   for   burrowing   in  sand-banks  and   making 
their  nests. 

The  tarsi  of  the  front-legs  are  dilated  in  many  male 
beetles,  or  are  furnished  with  broad  cushions  of  hairs ; 
and  in  many  genera  of  water-beetles  they  are  armed  with 
a  round  flat  sucker,  so  that  the  male  may  adhere  to  the 
slippery  body  of  the  female. 
It  is  a  much  more  unusual  cir- 
cumstance that  the  females  of 
some  water-beetles  (Dytiscus) 
have  their  elytra  deeply 
grooved,  and  in  Acilius  sul- 
catus  thickly  set  with  hairs, 
as  an  aid  to  the  male.  The 
females  of  some  other  water- 
beetles  (Hydroporus)  have 
their  elytra  punctured  for  the 
same  object. *  In  the  male  of 
Crabro  crihrarius  (fig.  8),  it  is 
the  tibia  which  is  dilated  into 
a  broad  horny  plate,  with  mi- 
nute membraneous  dots,  giv- 
ing to  it  a  singular  appearance 
like  that  of  a  riddle.'  In  the 
male  of  Penthe  (a  genus  of 
beetles)  a  few  of  the  middle  joints  of  the  antennae  are 
dilated  and  furnished  on  the  inferior  surface  with  cushions 
of  hair,  exactly  like  those  on  the  tarsi  of  the  Carabidas, 

^  We  have  here  a  curious  and  inexplicable  case  of  dimorphism,  for 
some  of  the  females  of  four  European  species  of  Dytiscus,  and  of  certain 
species  of  Hydroporus,  have  their  elytra  smooth ;  and  no  intermediate 
gradations  between  sulcated  or  punctured  and  quite  smooth  elytra  have 
been  observed.  See  Dr.  H.  Schaum,  as  quoted  in  the  '  Zoologist,'  vol. 
v.-vi.  1847-48,  p.  1896.  Also  Kirby  and  Spence,  'Introduction  to  En- 
tomology,' vol.  iii.  1826,  p.  305. 

'  Westwood,  '  Modern  Class.'  vol.  ii.  p.  193.    The  following  statement 


Fig.  8.— Crabro  cribrarius.     Upper 
figure,  ma;e  ;  lower  fii,'ure,  female. 


334 


SEXUAL   SELECTIQX. 


[Part  II. 


"nnd  obviously  for  the  same  end."  In  male  dragon-flics, 
"the  appendages  at  the  tip  of  the  tail  are  modified  in  an 
almost  infinite  variety  of  curious  patterns 
to  enable  them  to  embrace  the  neck  of  the 
female."  Lastly,  in  the  males  of  many  in- 
sects, the  legs  are  furnished  with  peculiar 
spines,  knobs,  or  spurs ;  or  the  whole  leg  is 
bowed  or  thickened,  but  this  is  by  no  means 
invariably  a  sexual  character ;  or  one  pair, 
or  all  three  pairs  are  elongated,  sometimes 
to  an  extravagant  length." 

In  all  the  orders,  the  sexes  of  many 
species  present  difierences,  of  which  the 
meaning  is  not  understood.  One  curious 
case  is  that  of  a  beetle  (fig.  9),  the  male  of 
which  has  the  left  mandible  much  enlarged ; 
so  that  the  mouth  is  greatly  distorted.  In 
another  Carabidous  beetle,  the  Eurygna- 
thus,'  we  have  tlie  unique  case,  as  far  as 
known  to  Mr.  Wollaston,  of  the  head  of  the 
female  being  much  broader  and  larger, 
though  in  a  variable  degree,  than  that  of 
the  male.  Any  number  of  such  cases  could 
be  given.  They  abound  in  the  Lepidoptera : 
one  of  the  most  extraordinary  is  that  cer- 
tain male  butterflies  have  their  fore-legs 
Fi  9  —  Taphro-  "^^rc  or  Icss  atrophied,  with  the  tibioD  and 
deres    (listortus  tarsi  reduced  to  mere  rudimentary  knobs. 

(much  enlarged).  •' 

Uppur     ligiirc.  ^hc  wincTS,  also,  in  the  two  sexes  often  differ 

male ;  lower  flg-  b   ■>  i 

ure,  female.         jji  ncuratiou,'"  and  sometimes  considerably 

about  Pcnthe,  and  others  in  inverted  commas,  are  taken  from  Mr.  Walsh, 
'  Practical  Entomologist,'  Philadelphia,  vol.  ii.  p.  88. 

*  Kirby  and  Spence,  '  Introduct.'  etc.,  vol.  iii.  pp.  332-336. 

'  'Insecta  Maderensia,'  1854,  p.  20. 

"  E.  Doubleday,  'Annals  and  Mag.  of  Nat.  Ilist.'  vol.  i.  1848,  p.  379. 


Chap.  X.]  INSECTS.  335 

in  outline,  as  in  the  Aricoris  epitus,  which  was  shown  to 
me  in  the  British  Museum  by  Mr.  A.  Butler.  The  males 
of  certain  South  American  butterflies  have  tufts  of  hair  on 
the  margins  of  the  wings,  and  horny  excrescences  on  the 
disks  of  the  posterior  pair."  In  several  British  butterflies, 
the  males  alone,  as  shown  by  Mr,  Wonfor,  are  in  parts 
clothed  with  peculiar  scales. 

The  purpose  of  the  luminosity  in  the  female  glow- 
worm is  likewise  not  understood ;  for  it  is  very  doubtful 
whether  the  primary  use  of  the  light  is  to  guide  the  male 
to  the  female.  It  is  no  serious  objection  to  this  latter  be- 
lief that  the  males  emit  a  feeble  light ;  for  secondary  sexu- 
al characters  pi'oper  to  one  sex  are  often  developed  in  a 
slight  degree  in  the  other  sex.  It  is  a  more  valid  objection 
that  the  larvte  shine,  and  in  some  species  brilliantly :  Fritz 
Miiller  informs  me  that  the  most  luminous  insect  which  he 
ever  beheld  in  Brazil  was  the  larva  of  some  beetle.  Both 
sexes  of  certain  luminous  species  of  Elater  emit  light. 
Kirby  and  Spence  suspect  that  the  phosphorescence  serves 
to  frighten  and  drive  away  enemies. 

Difference  in  Size  between  the  Sexes. — With  insects  of 
all  kinds  the  males  are  commonly  smaller  than  the  fe- 
males ;  '^  and  this  difierence  can  often  be  detected  even  in 
the  larval  state.  So  considerable  is  the  difierence  between 
the  male  and  female  cocoons  of  the  silk-moth  [Bombyx 
mori),  that  in  France  they  are  separated  by  a  particular 
mode  of  weighing.''     In  the  lower  classes  of  the  animal 

I  may  add  that  the  wings  in  certain  Hymenoptera  (see  Shuckard,  '  Fosso- 
rial  Hymenop.'  183*7,  pp.  39-43)  differ  in  neuration  according  to  sex. 

"  H.  W.  Bates,  in  'Journal  of  Proc.  Linn.  Soc'  vol.  vi.  1862,  p.  74. 
Mr.  Wonfor's  observations  are  quoted  in  '  Popular  Science  Review,'  1868, 
p.  343. 

"  Kirby  and  Spence,  '  Introduction  to  Entomology,'  vol.  iii.  p.  299. 

"  Robinet,  'Vers  h  Sole,'  1848,  p.  207. 


336  SEXUAL   SELECTION.  [Part  IL 

kingdom,  the  greater  size  of  the  females  seems  generally 
to  depend  on  their  developing  an  enormous  number  of  ova ; 
and  this  may  to  a  certain  extent  hold  good  with  insects. 
But  Dr.  Wallace  has  suggested  a  much  more  probable  ex- 
planation. He  finds,  after  carefully  attending  to  the  de- 
velopment of  the  caterpillars  of  Bomhyx  cynthia  and 
yama-mal,  and  especially  of  some  dwarfed  caterpillars 
reared  from  a  second  brood  on  unnatural  food,  "  that  in 
proportion  as  the  individual  moth  is  finer,  so  is  the  time 
required  for  its  metamorphosis  longer ;  and  for  this  reason 
the  female,  which  is  the  larger  and  heavier  insect,  from 
having  to  carry  her  numerous  eggs,  will  be  preceded  by 
the  male,  which  is  smaller  and  has  less  to  mature."  "  Now, 
as  most  insects  are  short-lived,  and  as  they  are  exposed  to 
many  dangers,  it  would  manifestly  be  advantageous  to  the 
female  to  be  impregnated  as  soon  as  possible.  This  end 
would  be  gained  by  the  males  being  first  matured  in  large 
numbers  ready  for  the  advent  of  the  females;  and  this 
again  would  naturally  follow,  as  Mr.  A.  R.  Wallace  has 
remarked,"  through  natural  selection ;  for  the  smaller 
males  would  be  first  matured,  and  thus  would  procreate  a 
large  number  of  offspring  which  would  inherit  the  reduced 
size  of  their  male  parents,  while  the  larger  males  from  be- 
ing matured  later  would  leave  fewer  offspring. 

There  are,  howcAcr,  exceptions  to  the  rule  of  male  in- 
sects being  smaller  than  the  females ;  and  some  of  these 
exceptions  are  intelligible.  Size  and  strength  would  be 
an  advantage  to  the  males,  which  fight  for  the  possession 
of  the  female;  and  m  these  cases  the  males,  as  with  the 
stag-beetle  (Lucanus),  are  larger  than  the  females.  There 
are,  liowever,  other  beetles  which  are  not  known  to  fight 
together,  of  which  the  males  exceed  the  females  in  size ; 
and  the  meaning  of  this  fact  is  not  known ;  but  in  some 

"  '  Transact.  Ent.  Soc'  3d  series,  vol.  v.  p.  486. 
1*  '  Journal  of  Proc.  Ent.  Soc'  Feb.  4,  186Y,  p.  Ixxi. 


Chap.  X.]  INSECTS.  337 

of  these  cases,  as  with  the  huge  Dynastes  and  Megasoma, 
we  can  at  least  see  that  there  would  be  no  necessity  for 
the  males  to  be  smaller  than  the  females,  in  order  to  be 
matured  before  them,  for  these  beetles  are  not  short-lived, 
and  there  would  be  ample  time  for  the  pairing  of  the  sexes. 
So,  again,  male  dragon-flies  (Libellulidse)  are  sometimes 
sensibly  larger,  and  never  smaller,  than  the  females  :"  and 
they  do  not,  as  Mr.  MacLachlan  believes,  generally  pair 
with  the  females,  until  a  week  or  fortnight  has  elapsed,  and 
until  they  have  assumed  their  proper  masculine  colors. 
But  the  most  curious  case,  showing  on  what  complex  and 
easily-overlooked  relations  so  trifling  a  character  as  a 
difference  in  size  between  the  sexes  may  depend,  is  that  of 
the  aculeate  Hymenoptera  ;  for  Mr.  F.  Smith  informs^  me 
that  throughout  nearly  the  whole  of  this  large  group  the 
males,  in  accordance  with  the  general  rule,  are  smaller 
than  the  females  and  emerge  about  a  week  before  them ; 
but  among  the  Bees,  the  males  of  Apis  melUJica,  Anthi- 
dium  tnanicatum  and  Anthophora  acervorwn,  and  among 
the  Fossores,  the  males  of  the  3Iethoca  ichneximonides^ 
are  larger  than  the  females.  The  explanation  of  this 
anomaly  is  that  a  marriage-flight  is  absolutely  necessary 
with  these  species,  and  the  males  require  great  strength 
and  size  in  order  to  carry  the  females  through  the  air.  In- 
creased size  has  here  been  acquired  in  opposition  to  the 
usual  relation  between  size  and  the  period  of  development, 
for  the  males,  though  larger,  emerge  l)efore  the  smaller  fe- 
males. 

We  will  now  review  the  several  Orders,  selecting  such 
facts  as  more  particularly  concern  us.  The  Lepidoptera 
(Butterflies  and  Moths)  will  be  retained  for  a  separate 
chapter. 

''  For  this  and  other  statements  on  the  size  of  the  sexes,  see  Kirby 
and  Spence,  ibid.  vol.  iii.  p.  300 ;  on  the  duration  of  life  in  insects,  see 
p.  844. 


338  SEXUAL   SELECTION.  [Part  U 

Order,  Thysanura. — The  members  of  this  Order  are 
lowly  organized  for  their  class.  They  are  wingless,  dull- 
colored,  minute  insects,  with  ugly,  almost  misshapen  heads 
and  bodies.  The  sexes  do  not  differ ;  but  they  offer  one 
interesting  fact,  by  showing  that  the  males  pay  sedulous 
court  to  their  females  even  low  down  in  the  animal  scale. 
Sir  J,  Lubbock,"  in  describing  the  Smynthurus  luteus, 
says :  "  It  is  very  amusing  to  see  these  little  creatures  co- 
quetting together.  The  male,  which  is  much  smaller  than 
the  female,  runs  round  her,  and  they  butt  one  another, 
standing  face  to  face,  and  moving  backward  and  forward 
like  two  playful  lambs.  Then  the  female  pretends  to  run 
away  and  the  male  runs  after  her  with  a  queer  appearance 
of  g.nger,  gets  in  front  and  stands  facing  her  again  ;  then 
she  turns  coyly  round,  but  he,  quicker  and  more  active, 
scuttles  round  too,  and  seems  to  whip  her  with  his  antennae ; 
then  for  a  bit  they  stand  face  to  face,  play  with  their  an- 
tennsB,  and  seem  to  be  all  in  all  to  one  another." 

Order,  Diptera  (Flies). — The  sexes  differ  little  in  color. 
The  greatest  difference,  known  to  Mr.  F.  Walker,  is  in  the 
genus  Bibio,  in  which  the  males  are  blackish  or  quite 
black,  and  the  females  obscure  brownish  orange.  The 
genus  Elaphomyia,  discovered  by  Mr.  Wallace  "  in  New 
Guinea,  is  highly  remarkable,  as  the  males  are  furnished 
with  horns,  of  which  the  females  are  qviite  destitute.  The 
horns  spring  from  beneath  the  eyes,  and  curiously  resemble 
those  of  stags,  being  either  branclied  or  palmated.  They 
equal  in  length  the  whole  of  the  body  in  one  of  the  spe- 
cies. They  might  be  thought  to  serve  for  fighting,  but,  as 
in  one  species  they  are  of  a  beautiful  pink-color,  edged 
with  black,  with  a  pale  central  stripe,  and  as  these  insects 
have  altogether  a  very  elegant  appearance,  it  is  perhaps 

"  '  Transact.  Linnean  Soc'  vol.  xxvi.  1868,  p.  296. 
"  '  The  Malay  Archipelago,'  vol  ii.  1869,  p.  313. 


Chap.  X.]  DIPTERA  AND   HEMIPTERA.  339 

more  probable  that  the  horns  serve  as  ornaments.  That 
the  males  of  some  Diptera  fight  together  is  certain ;  for 
Prof.  Westwood  "  has  several  times  seen  this  with  some 
species  of  Tipula  or  Harry-long-legs.  Many  observers 
believe  that  when  gnats  (Culiciclte)  dance  in  the  air  in  a 
body,  alternately  rising  and  falling,  the  males  are  courting 
the  females.  The  mental  faculties  of  the  Diptera  are 
probably  fairly  well  developed,  for  their  nervous  system 
is  more  higlily  developed  than  in  most  other  Orders  of  in- 
sects.'" 

Order,  Semiptera  (Field-Bugs). — Mr.  J.  W.  Douglas, 
who  has  particularly  attended  to  the  British  species,  has 
kindly  given  me  an  account  of  their  sexual  differences. 
The  males  of  some  species  are  furnished  with  wings, 
while  the  females  are  wingless ;  the  sexes  differ  in  the 
form  of  the  body  and  elytra;  in  the  second  joints  of  their 
antennae  and  in  their  tarsi ;  but,  as  the  signification  of 
these  differences  is  quite  unknown,  they  may  be  here 
passed  over.  The  females  are  generally  larger  and  more 
robust  than  the  males.  With  British,  and,  as  far  as  Mr. 
Douglas  knows,  with  exotic  species,  the  sexes  do  not  com- 
monly differ  much  in  color ;  but  in  about  six  British  spe- 
cies the  male  is  considerably  darker  than  the  female,  and 
in  about  four  other  species  the  female  is  darker  than  the 
male.  Both  sexes  of  some  species  are  beautifully  marked 
with  vermilion  and  black.  It  is  doubtful  whether  these 
colors  serve  as  a  protection.  If  in  any  species  the  males 
had  differed  from  the  females  in  an  analogous  manner,  we 
might  have  been  justified  in  attiibuting  such  conspicuous 
colors  to  sexual  selection  with  transference  to  both  sexes. 

Some  species  of  Reduvidoe  make  a  stridulating  noise  ; 

"  'Modern  Classification  of  Insects,'  vol.  ii.  1840,  p.  526. 
*•*  See  Mr.  B.  T.  Lowne's  very  interesting  work,  '  On  the  Anatomy  of 
the  Blow-Fly,  Musca  vomitoria,'  1870,  p.  14. 


340  SEXUAL   SELECTION.  [Part  I L 

and,  in  tlie  case  of  Pirates  stridulus^  this  is  said  "  to  be 
effected  by  the  movement  of  the  neck  within  the  pro- 
thoracic  cavity.  According  to  Westring,  Heduvius  per- 
so?iatus  also  stridulates.  But  I  have  not  been  able  to 
learn  any  particulars  about  these  insects ;  nor  have  I  any 
reason  to  suppose  that  they  differ  sexually  in  this  respect. 

Order,  Homoptera. — Every  one  who  has  wandered  in 
a  tropical  forest  must  have  been  astonished  at  the  din 
made  by  the  male  Cicadae.  The  females  ai-e  mute ;  as  the 
Grecian  poet  Xenarchus  says,  "  Happy  the  Cicadas  live, 
since  they  all  have  voiceless  wives."  The  noise  thus  made 
could  be  plainly  heard  on  board  the  "Beagle,"  when 
anchored  at  a  quarter  of  a  mile  from  the  shore  of  Brazil ; 
and  Captain  Hancock  says  it  can  be  heard  at  the  distance 
of  a  mile.  The  Greeks  formerly  kept,  and  the  Chinese 
now  keep,  these  insects  in  cages  for  the  sake  of  their  song, 
so  that  it  must  be  pleasing  to  the  ears  of  some  men." 
The  Cicadidje  usually  sing  during  the  day;  while  the 
Fulgoridse  appear  to  be  night-songsters.  The  sound,  ac- 
cording to  Landois,"'  who  has  recently  studied  the  subject, 
is  produced  by  the  vibration  of  the  lips  of  the  spiracles, 
which  are  set  into  motion  by  a  current  of  air  emitted  from 
the  tracheae.  It  is  increased  by  a  wonderfully  complex 
resounding  apparatus,  consisting  of  two  cavities  covered 
by  scales.  Hence  the  sound  may  truly  be  called  a  voice. 
In  the  female  the  musical  apparatus  is  present,  but  very 
much  less  developed  than  in  the  male,  and  is  never  used 
for  producing  sound. 

With  respect  to  the  object  of  the  music.  Dr.  Hartman, 

*'  Westwood,  '  Modern  Class,  of  Insects,'  vol.  ii.  p.  473. 

"  These  particulars  are  taken  from  Westwood's  '  Modern  Class,  of 
Insects,'  vol.  ii.  1840,  p.  422.  See,  also,  on  the  Fulgorida?,  Kirby  and 
Spence,  '  Introduct.'  vol.  ii.  p.  401. 

"  'Zeitschrift  fur  wissenschaft.  Zoolog.'  B.  xvii.  1867,  s.  152-158. 


Chap.  X.]  HOMOPTERA.  341 

in  speaking  of  the  cicada  septemdecim  of  the  United 
States,  says :"  "  The  drums  are  now  (June  6th  and  7th, 
1851)  heard  in  all  directions.  This  I  believe  to  be  the 
marital  summons  from  the  males.  •Standing  in  thick 
chestnut-sprouts  about  as  high  as  my  head,  where  hun- 
dreds were  around  me,  I  observed  the  females  coming 
around  the  drumming  males."  He  adds :  "  This  season 
(August,  1868)  a  dwarf  pear-tree  in  my  garden  produced 
about  fifty  larvre  of  Gic.  pruinosa ;  and  I  several  times 
noticed  the  females  to  alight  near  a  male  while  he  was  ut- 
tering his  clanging  notes."  Fritz  Mtiller  writes  to  me 
from  Southern  Brazil  that  he  has  often  listened  to  a  musi- 
cal contest  between  two  or  three  males  of  a  Cicada,  hav- 
ing a  particularly  loud  voice,  and  seated  at  a  considerable 
distance  from  each  other.  As  soon  as  the  first  had  fin- 
ished his  song,  a  second  immediately  began ;  and  after  he 
had  concluded,  another  began,  and  so  on.  As  there  is  so 
much  rivalry  between  the  males,  it  is  probable  that  the 
females  not  only  discover  them  by  the  sounds  emitted,  but 
that,  like  female  birds,  they  are  excited  or  allured  by  the 
male  with  the  most  atti'active  voice. 

I  have  not  found  any  well-marked  cases  of  ornamental 
differences  between  the  sexes  of  the  Homoptera.  Mr. 
Douglas  informs  me  that  there  are  three  British  species, 
in  which  the  male  is  black  or  marked  with  black  bands, 
while  the  females  are  pale-colored  or  obscure. 

Order,  Orthoptera. — The  males  in  the  three  saltatorial 
families  belonging  to  this  Order  are  remarkable  for  their 
musical  powers,  namely,  the  Achetidae  or  crickets,  the 
Locustidoe  for  which  there  is  no  exact  equivalent  name  in 
English,  and  the  Acridiidae  or  grasshoppers.  The  stridu- 
lation  produced  by  some  of  the  Locustidre  is  so  loud  that 

'*  I  am  indebted  to  Mr.  "Walsh  for  having  sent  me  this  extract  from  a 
'  Journal  of  the  Doings  of  Cicada  septemdecim,'  by  Dr.  Hartman. 


342 


SEXUAL   SELECTION. 


[Part  IL 


it  can  be  heard  during  the  niglit  at  the  distance  of  a 
mile ; "  and  that  made  by  certain  species  is  not  mimusical 
even  to  the  human  ear,  so  that  the  Indians  on  the  Ama- 
zons keep  them  in  wicker  cages.  All  observers  agree  that 
the  sounds  serve  either  to  call  or  excite  the  mute  females. 
But  it  has  been  noticed  "  that  the  male  migratory  locust 
of  Russia  (one  of  the  Acridiidaj),  while  coupled  with  the 
female,  stridulates  from  anger  or  jealousy  when  ap- 
proached by  another  male.  The  house-cricket  when  sur- 
prised at  night  uses  its  voice  to  warn  its  fellows."  In 
North  America  the  Katy-did    {Platyphyllum  concavum^ 

one  of  the  Locustidse)  is 
described  ^'  as  mounting 
on  the  upper  branches  of  a 
tree,  and  in  the  evening  be- 
ginning his  noisy  babble, 
while  rival  notes  issue  from 
the  neighboring  trees,  and 
the  groves  resound  with  the 
call  of  Katy  -  did  -  she  -  did 
the  live-long  night."  Mr. 
Bates,  in  speaking  of  the 
European  field-cricket  (one 
of  the  Achetidai),  says: 
"The  male  has  been  ob- 
served to  place  itself  in  the 
evening  at  the  entrance  of 
its  burrow,  and  stridulate 
until  a  female  approaches,  when  the  louder .  notes  are 
succeeded  by  a  more  subdued  tone,  while  the  success- 
ful musician  caresses  with  his  antennne  the  mate  he  has 

-'  L.  Guilding,  '  Transact.  Linn.  Soc'  vol.  xv.  p.  154. 
^^  Kiippen,  as  quoted  in  the  'Zooloffical  Record,'  for  1867,  p.  460. 
"  Gilbert  White,  'Nat.  Hist,  of  Selbornc,'  vol.  ii.  1825,  p.  262. 
"  Harris,  'Insects  of  New  England,'  1842,  p.  128. 


Fig.  10.— Qryllus  campestris  (from  Lan- 
dois). 

Risht-hand  floiire.  under  side  of  part  of 
the  wing-nervuro,  much  maguifled, 
showinn;  the  Iceth,  st. 

Left-hand  fitrure,  upper  surface  of  wing- 
cover,  with  the  projecting,  smooth  ner- 
vure,  r,  across  which  the  teeth  {st)  are 
scraped. 


Chap.  X.]  ORTHOPTERA.  343 

won."  ^®  Dr.  Scudder  was  able  to  excite  one  of  these  in- 
sects to  answer  him,  by  rubbing  on  a  file  with  a  quill. ^" 
In  both  sexes  a  remarkable  auditory  apparatus  has  been 
discovered  by, Von  Siebold,  situated  in  the  front  legs.^^ 

In  the  three  Families  the  sounds  are  differently  pro- 
duced. In  the  males  of  the  Achetidoe  both  wing-covers 
have  the  same  structure ;  and  this  in  the  field-cricket 
{Gryllus  canipestrls^  fig.  10)  consists,  as  described  by 
Landois,^''  of  from  131  to  138  sharp,  transverse  ridges  or 
teeth  {st)  on  the  under  side  of  one  of  the  nervures  of  the 
wing-cover.  This  toothed  nervure  is  rapidly  scraped 
across  a  projecting,  smooth,  hard  nervure  (r)  on  the  upper 
surface  of  the  opposite  wing.  First  one 
wing  is  rubbed  over  the  other,  and  then 
the  movement  is  reversed.  Both  wings 
are  raised  a  little  at  the  same  time,  so 
as  to  increase  the  resonance.  In  some 
species  the  wing-covers  of  the  males  are 
furnished  at  the  base  with  a  talc-like 
plate.''  I  have  here  given  a  drawing  (iig. 
11)  of  the  teeth  on  the  under  side  of  the  p-j^  -^-^^  —Teeth  of 
nervure  of  another  species  of  Gryllus,  viz.,      ^Sfcus^ffm 

G.  domestictlS.  Landois). 

In  the  Locustidee  the  opposite  wing-covers  differ  in 
structure  (fig.  12),  and  cannot,  as  in  the  last  family,  be  in- 
differently used  in  a  reversed  manner.  The  left  wing, 
which  acts  as  the  bow  of  the  fiddle,  lies  over  the  right 

^^  'The  Naturalist  on  the  Amazons,'  vol.  i.  1863,  p  252.  Mr.  Bates 
gives  a  very  interesting  discussion  on  the  gradations  in  the  musical  appa- 
ratus of  the  three  families.  See  also  Westwood,  *  Modem  Class.'  vol.  ii. 
pp.  445,  453. 

30  '  Proc.  Boston  Soc.  of  Nat.  Hist.'  vol.  xi.  April,  1868. 

3'  'Nouveau  Manuel  d'Anat.  Comp.'  (French  translat.),  torn.  i.  1850, 

p.  set. 

8'  'Zeitschrift  fiir  wissenschaft.  Zoolog.'  B.  xvii.  1867,  s.  117. 
^  Westwood,  '  Modem  Class,  of  Insects,'  vol  i.  p.  440. 


344 


SEXUAL   SELECTIOX. 


[I'aut  II. 


wing  which  serves  as  the  liddle  itself.  One  of  the  ner- 
vures  (a)  ou  the  under  surface  of  the  former  is  finely  ser- 
rated, aud  is  scraped  across  the  prominent  nervures  on  the 
upper  surface  of  the  opposite  or  right  wing.  In  our  Brit- 
isii  FJcasfjonura  viridisshna  it  appeared  to  me  that  the 
serrated  nervure  is  rubbed  against  the  rounded  hind 
corner  of  the  opposite  wing,  the  edge  of  which  is  thick- 
ened, colored  brown,  and  very  yharp.  In  the  right  wing, 
but  not  in  the  left,  there  is  a  little  plate,  as  transparent  as 
talc,  surrounded  by  nervures,  and  called  the  speculum. 
In  Ephippiger  vitium^  a  member  of  this  same  family,  we 
have  a  curioiis  subordinate  modification ;  for  the  wing- 
covers  are  greatly  reduced  in  size,  but  "  the  posterior  part 
of  the  pro-thorax  is  elevated  into  a  kind  of  dome  over  the 


Fig.  12.— Chlorocaslus  Tanana  (from  BatesV    a.  b.  Lobes  of  opposite  winjj-coveis. 


Chap.  X.]  ORTHOPTERA.  345 

wing-covers,  and  which  has  probably  the  effect  of  increas- 
ing the  sound."  " 

We  thus  see  that  the  musical  apparatus  is  more  differ- 
entiated or  specialized  in  the  Locustidse,  which  includes, 
I  believe,  the  most  powerful  performers  in  the  Order,  than 
in  the  Achetidae,  in  which  both  wing-covers  have  the 
same  structure  and  the  same  function/''  Landois,  however, 
detected  in  one  of  the  Locustidge,  namely,  in  Decticus, 
a  short  and  narrow  roAV  of  small  teeth,  mere  rudiments,  on 
the  inferior  surface  of  the  right  wing-cover,  which  under- 
lies the  other  and  is  never  used  as  the  bow.  I  observed 
the  same  rudimentary  structure  on  the  under  side  of  the 
right  wing-cover  in  Phasgonura  viridissima.  Hence  we 
may  with  confidence  infer  that  the  Locustidoe  are  de- 
scended from  a  form,  in  which,  as  in  the  existing  Ache- 
tidae,  both  wing-covers  had  serrated  nervures  on  the  under 
surface,  and  could  be  indifferently  used  as  the  bow ;  but 
that  in  the  Locustidge  the  two  wing-covers  gradually  be- 
came differentiated  and  perfected,  on  the  principle  of  the 
division  of  labor,  the  one  to  act  exclusively  as  the  bow 
and  the  other  as  the  fiddle.  By  what  steps  the  more 
simple  apparatus  in  the  Achetidae  originated,  we  do  not 
know,  but  it  is  probable  that  the  basal  portions  of  the 
wing-covers  overlapped  each  other  formerly  as  at  present, 
and  that  the  friction  of  the  nervures  produced  a  grating 
sound,  as  I  find  is  now  the  case  with  the  wing-covers  of 
the  females.^'  A  grating  sound  thus  occasionally  and  ac- 
cidentally made  by  the  males,  if  it  served  them  ever  so 
little  as  a  love-call  to  the  females,  might  readily  have  been 
intensified  through  sexual  selection  by  fitting  variations  in 
the  roughness  of  the  nervures  having  been  continually 
preserved. 

^  "Westwood,  '  Modem  Class,  of  Insects,'  vol.  i.  p.  453. 

«^  Landois,  ibid.  s.  121,  122. 

'•  Mr.  Walsh  also  informs  me  that  he  has  noticed  that  the  female  of 


346 


SEXUAL   SELECTION. 


[Part  IL 


In  the  last  and  third  Family,  namely,  the  Acridiidse 
or  o-rasshoppcrs,  the  stridulation  is  produced  in  a  very 
diftercnt  nuuiner,  and  is  not  so  shrill,  according  to  Dr. 
Scudder  as  in  the  preceding  Families.  The  inner  surface 
of  the  femur  (fig.  13,  r)  is  furnished  with  a  longitudinal 
row  of  minute,  elegant,  lancet-shaped,  elastic  teeth,  from 
85  to  93  in  number;"  and  these  are  scraped  across  the 
sharp,  projecting  nervures  on  the  wing-covers,  which  are 
thus  made  to  vibrate  and  resound.     Harris"  says  that 

when  one  of  the  males 
begins  to  play,  he  first 
"bends  the  shank  of 
the  hind-leg  beneath  the 
thigh,  where  it  is  lodged 
in  a  furrow  designed  to 
receive  it,  and  then  draws 
the  leg  briskly  up  and 
down.  He  does  not  play 
both  fiddles  together,  but 
alternately  first  upon  one 
and  then  on  the  other." 

Fig.  13.— Hind-lcs^ofStenobothnispratorum:   T„  ,vio,i-tr  cnp^^pa  thp  bnsp 
r,  the  strululating  ridiic;    loWer  fl-ure,   "^  many  SpCCieS  tnc  oase 

the  teeth,  forming:  the  ridge,  much  mag-  f.f    f]-,p.    ohdonipn    is    hol- 
nilied  (from  Landois).  ^    OT.    int    auuoiiitu    it>    uui 

lowed  out  into  a  great 
cavity  which  is  believed  to  act  as  a  resounding-board.  In 
Pneumora  (fig.  14),  a  South  African  genus  belonging  to  this 
same  family,  we  meet  with  a  new  and  remarkable  modifi- 
cation :  in  the  males  a  small  notched  ridge  projects  ob- 
liquely from  each  side  of  the  abdomen,  against  which  the 
hind  femora  are  rubbed. '°    As  the  male  is  furnished  with 

the  Platiiphyllum  concavum,  "  when  captured,  makes  a  feeble  grating 
noise  by  shuffling  her  wing-covers  together." 
31  Landois,  ibid.  s.  113. 

38  'Insects  of  New  England,'  1842,  p.  133. 

39  Westwood,  '  Modem  Classification,'  vol.  i.  p.  462. 


Chap.  X.] 


ORTHOPTERA. 


547 


wings,  the  female  being  wingless,  it  is  remarkable  that 
the  thighs  are  not  rubbed  in  the  usual  manner  against  the 
wing-covers ;  but  this  may  perhaps  be  accounted  for  by 
the  unusually  small  size  of  the  hind-legs.  I  have  not  been 
able  to.  examine  the  inner  surface  of  the  thighs,  which, 
judging  from  analogy,  would  be  finely  serrated.  The 
species  of  Pneumora  have  been  more  profoundly  modified 
for  the  sake  of  stridulation  than  any  other  orthopterous 
insect ;  for  in  the  male  the  whole  body  has  been  converted 


Fig.  14.— Pnenmora  (from  specimens  in  the  Biitish  Museum).    Upper  figure, 
male  ;  lower  figure,  female. 


348  SEXUAL  SELECTION.  [Part  IL 

into  a  musical  instrument,  being  distended  with  air,  like  a 
great  pellucid  bladder,  so  as  to  increase  the  resonance. 
Mr.  Trimen  infonns  me  that  at  the  Cape  of  Good  Hope 
these  insects  make  a  wonderful  noise  during  the  night. 

There  is  one  exception  to  the  rule  that  the  females  in 
these  three  Families  are  destitute  of  an  eflScient  musical 
apparatus ;  for  both  sexes  of  Ephippiger  (Locustidse)  are 
said  *"  to  be  thus  provided.  This  case  may  be  compared 
with  that  of  the  reindeer,  in  which  species  alone  both 
sexes  possess  horns.  Although  the  female  orthoptera  are 
thus  almost  invariably  mute,  yet  Landois  *'  found  rudi- 
ments of  the  stridulating  organs  on  the  femora  of  the  fe- 
male Acridiidoe,  and  similar  rudiments  on  the  under  sur- 
face of  the  wing-covers  of  the  female  Achetid® ;  but  he 
failed  to  find  any  rudiments  in  the  females  of  Decticus, 
one  of  the  Locustida.  In  the  Homoptera,  the  mute  fe- 
males of  Cicada  have  the  proper  musical  apparatus  in  an 
undeveloped  state ;  and  we  shall  hereafter  meet,  in  other 
divisions  of  the  animal  kingdom,  with  innumerable  in- 
stances of  structures  proper  to  the  male  being  present  in 
a  rudimentary  condition  in  the  female.  Such  cases  appear 
at  first  sight  to  indicate  that  both  sexes  were  primordially 
constructed  in  the  same  manner,  but  that  certain  organs 
were  subsequently  lost  by  the  females.  It  is,  however,  a 
more  probable  view,  as  previously  explained,  that  the  or- 
gans in  question  were  acquired  by  the  males  and  partially 
transferred  to  the  females. 

Landois  has  observed  another  interesting  fact,  namely, 
that,  in  the  females  of  the  Acridiidte,  the  stridulating  teeth 
on  tlie  femora  remain  throughout  life  in  the  same  condition 
in  which  they  first  appear  in  both  sexes  during  the  larval 
state.  In  the  males,  on  the  other  hand,  they  become 
fully  developed   and   acquire   their   perfect   structure  at 

"  Westwood,  ibid.  vol.  i.  p.  453. 

«»  Landois,  ibid.  s.  115,  116,  120,  122. 


Chap.  X.]  ORTHOPTERA.  349 

the  last  moult,  when  the  insect  is  mature  and  ready  to 
breed. 

From  the  facts  now  given,  we  see  that  the  means  by 
which  the  males  produce  their  sounds  are  extremely  di- 
versified in  the  Orthoptera,  and  are  altogether  difierent 
from  those  employed  by  the  Homoptera,  But  throughout 
the  animal  kingdom  we  incessantly  find  the  same  object 
gained  by  the  most  diversified  means ;  this  being  due  to 
the  whole  organization  undergoing  in  the  course  of  ages 
multifarious  changes ;  and,  as  part  after  pai*t  varies,  differ- 
ent variations  are  taken  advantage  of  for  the  same  gen- 
eral purpose.  The  diversification  of  the  means  for  pro- 
ducing sound,  in  the  three  families  of  the  Orthoptera  and 
in  the  Homoptera,  impresses  the  mind  Avith  the  high  im- 
portance of  these  structures  to  the  males,  for  the  sake  of 
calling  or  alluring  the  females.  We  need  feel  no  surprise 
at  the  amount  of  modification  which  the  Orthoptera  have 
undergone  in  this  respect,  as  we  now  know,  from  Dr. 
Scudder's  remarkable  discovery,*^  that  there  has  been 
more  than  ample  time.  This  naturalist  has  lately  found  a 
fossil  insect  in  the  Devonian  formation  of  New  Bruns- 
wick,, which  is  furnished  with  "  the  well-known  tympanum 
or  stridulating  apparatus  of  the  male  Locustidoe."  This 
insect,  though  in  most  respects  related  to  the  ISTeuroptera, 
appears  to  connect,  as  is  so  often  the  case  with  very  an- 
cient forms,  the  two  Orders  of  the  Neuroptera  and  Or- 
thoptera which  are  now  generally  ranked  as  quite  distinct. 

I  have  but  little  more  to  say  on  the  Orthoptera.  Some 
of  the  species  are  very  pugnacious :  when  two  male  field- 
crickets  {Gryllus  campestris)  are  confined  together,  they 
fight  till  one  kills  the  other ;  and  the  species  of  Nantis  are 
described  as  manoeuvring  with  their  sword-like  front-limbs, 
like  hussars  with  their  sabres.     The  Chinese  keep  these 

*'  '  Transact.  Ent.  Soc'  3d  series,  vol.  ii.  ('  Journal  of  Proceedings,' 
p.  117.) 


350  SEXUAL   SELECTION.  [Part  IL 

insects  in  little  bamboo  cages  and  match  them  like  game- 
cocks." With  respect  to  color,  some  exotic  locusts  are 
beautifully  ornamented  ;  the  posterior  wings  being  marked 
with  red,  blue,  and  black ;  but,  as  throughout  the  Order 
the  two  sexes  rarely  differ  much  in  color,  it  is  doubtful 
whether  they  owe  these  bright  tints  to  sexual  selection. 
Conspicuous  colors  may  be  of  use  to  these  insects  as  a 
protection,  on  the  principle  to  be  explained  in  the  next 
chapter,  by  giving  notice  to  their  enemies  that  they  are 
unpalatable.  Thus  it  has  been  observed  "  that  an  Indian 
brightly-colored  locust  was  invariably  rejected  when  of- 
fered to  birds  and  lizards.  Some  cases,  however,  of  sex- 
ual differences  in  color  in  this  Order  are  known.  The 
male  of  an  American  ci'icket"  is  described  as  being  as 
white  as  ivory,  while  the  female  varies  from  almost  white 
to  greenish  yellow  or  dusky.  Mr.  Walsh  informs  me 
that  the  adult  male  of  Spectrum  femoratum  (one  of 
the  Phasmida?)  "is  of  a  shining  brownish-yellow  color; 
the  adult  female  being  of  a  dull,  opaque,  cinereous  brown; 
the  young  of  both  sexes  being  gi-een."  Lastly,  I  may 
mention  that  the  male  of  one  curious  kind  of  cricket "  is 
furnished  with  "a  long  membranous  appendage,  which 
falls  over  the  face  like  a  veil ; "  but  whether  this  serves 
as  an  ornament  is  not  known. 

Order,  Neuroptera. — Little  need  here  be  said,  except 
in  regard  to  color.  In  the  Ephemeridtc  the  sexes  often 
differ  slightly  in  their  obscure  tints ;  *'  but  it  is  not  prob- 

*'  Westwood,  '  Modern  Class,  of  Insects,'  vol.  i.  p.  427  ;  for  crickets, 
p.  445. 

**  Mr.  Ch.  Home,  in  'Proc.  Ent.  Soc'  May  3,  1869,  p.  xii. 

^' The  Oecanlhus  nivalis.  Harris,  '  Insects  of  Now  England,'  1842, 
p.  124. 

*"  Platyblemnus  :  Westwood,  '  Modern  Class.'  vol.  i.  p.  447. 

*'  B.  D.  Walsh,  the  Pscudo-neuroptera  of  Illinois,  in  '  Proc.  Ent.  Soc 
of  Philadelphia,'  1862,  p.  361. 


Chap.  X.'J  NEUROPTERA.  351 

able  that  the  males  are  thus  rendered  attractive  to  the 
females.     The  LibellulidoB  or  dragon-flies  are  ornamented 
with  splendid  green,  blue,  yellow,  and  vermilion  metallic 
tints ;  and  the  sexes  often  differ.     Thus,  the  males  of  some 
of  the  Agrionidte,  as  Prof.  Westwood  remarks,"  "  are  of 
a  rich  blue  with  black  wings,  while  the  females  ai-e  fine 
green  with  colorless  wings."     But  in  Agrion  Hamburii 
these  colors  are  exactly  reversed  in  the  two  sexes."     In  the 
extensive  North  American  genus  of  Hetaerina,  the  males 
alone  have  a  beautiful  carmine  spot  at  the  base  of  each 
wing.     In  Anax  Junius  the  basal  part  of  the  abdomen  in 
the  male  is  a  vivid  ultra-marine  blue,  and  in  the  female 
grass-green.     In  the  allied  genus  Gomphus,  on  the  other 
hand,  and  in  some  other  genera,  the  sexes  differ  but  little 
in  color.     Throughout  the  animal  kingdom,  similar  cases 
of  the  sexes  of  closely-allied  forms  either  differing  greatly, 
or  very  little,  or  not  at  all,  are   of  frequent  occurrence. 
Although  with  many  Libellulidse  there  is  so  wide  a  differ- 
ence in  color  between  the  sexes,  it  is  often  difficult  to  say 
which  is  the  most  brilliant ;  and  the  ordinary  coloration 
of  the  two  sexes  is  exactly  reversed,  as  we  have  just  seen, 
in  one  species  of  Agrion.     It  is  not  probable  that  their 
colors  in  any  case  have  been  gained  as  a  protection.     As 
Mr,  MacLachlan,  who  has  closely  attended  to  this  family, 
writes  to  me,  dragon-flies — the  tyrants  of  the  insect-world 
— are  the  least  liable  of  any  insect  to  be  attacked  by  birds 
or  other  enemies.     He  believes  that  their  bright  colors 
serve  as  a  sexual  attraction.    It  deserves  notice,  as  bearing 
on  this  subject,  that  certain  dragon-flies  appear  to  be  at- 
tracted by  particular  colors :  Mr.  Patterson  observed  ^°  that 
the  species  of  Agrionidse,  of  which  the  males  are  blue, 

^^ '  Modern  Class.'  vol.  ii.  p.  3*7. 

*9  Walsh,  ibid.  p.  381.    I  am  indebted  to  this  naturalist  for  the  follow- 
ing facts  on  Hetffirina,  Anax,  and  Gomphus. 
'"  'Transact.  Ent.  Soc.'  vol.  i.  1836,  p.  Ixxxl 


352  SEXUAL   SELECTION.  [Part  II. 

settled  in  numbers  on  the  blue  float  of  a  fishing-line ;  while 
two  other  species  were  attracted  by  shining  white  colors. 

It  is  an  interesting  fact,  first  observed  by  Schelver, 
that  the  males,  in  several  genera  belonging  to  two  sub- 
families, when  they  first  emerge  from  the  pupal  state  are 
colored  exactly  like  the  females ;  but  that  their  bodies  in 
a  short  time  assume  a  conspicuous  milky-blue  tint,  owing 
to  the  exudation  of  a  kind  of  oil,  soluble  in  ether  and  alco- 
hol. Mr,  MacLachlan  believes  that  in  the  male  of  Libel- 
lula  depressa  this  change  of  color  does  not  occur  until 
nearly  a  fortnight  after  the  metamorphosis,  when  the  sexes 
are  ready  to  pair. 

Certain  species  of  Neurothemis  present,  according  to 
Brauer,"  a  curious  case  of  dimorphism,  some  of  the  females 
having  their  wings  netted  in  the  usual  manner;  while 
other  females  have  them  "  very  richly  netted  as  in  the 
males  of  the  same  species."  Brauer  "  explains  the  phe- 
nomenon on  Darwinian  principles  by  the  supposition  that 
the  close  netting  of  the  veins  is  a  secondary  sexual  char- 
acter in  the  males."  This  latter  character  is  generally  de- 
veloped in  the  males  alone,  but  being,  like  every  other 
masculine  character,  latent  in  the  female,  is  occasionally 
developed  in  them.  We  have  here  an  illustration  of  the 
manner  in  which  the  two  sexes  of  many  animals  have 
probably  come  to  resemble  each  other,  namely,  by  varia- 
tions first  appearing  in  the  males,  being  preserved  in 
them,  and  then  transmitted  to  and  developed  in  the  fe- 
males ;  but  in  this  particular  genus  a  complete  transference 
is  occasionally  and  abruptly  efiected.  Mr.  MacLachlan 
informs  me  of  another  case  of  dimorphism  occurring  in 
several  species  of  Agrion  in  which  a  certain  number  of 
individuals  are  found  of  an  orange-color,  and  these  are  in- 
variably females.  This  is  probably  a  case  of  reversion, 
for  in  the  true  Libellulae,  when  the  sexes  differ  in  color, 

^'  See  abstract  in  the  'Zoological  Record'  for  1867,  p.  450. 


Chap.  X.]  HYMENOPTERA.  353 

the  females  are  always  orange  or  yellow,  so  that,  supposing 
Agrion  to  be  descended  from  some  primordial  form  hav- 
ing the  characteristic  sexual  colors  of  the  typical  Libelluloe, 
it  would  not  be  surprising  that  a  tendency  to  vary  in  this 
manner  should  occur  in  the  females  alone. 

Although  many  dragon-flies  are  such  large,  powerful, 
and  fierce  insects,  the  males  have  not  been  observed  by 
Mr.  MacLachlan  to  fight  together,  except,  as  he  believes, 
in  the  case  of  some  of  the  smaller  species  of  Agrion.  In 
another  very  distinct  group  in  this  Order,  namely,  in  the 
Termites  or  white  ants,  both  sexes  at  the  time  of  swarm- 
ing may  be  seen  running  about,  "  the  male  after  the  fe- 
male, sometimes  two  chasing  one  female,  and  contending 
with  great  eagerness  who  shall  win  the  prize."  ^^ 

Order,  Ilyinenoptera. — That  inimitable  observer  M. 
Fabre,"  in  describing  the  habits  of  Cerceris,  a  wasp-like 
insect,  remarks  that  "  fights  frequently  ensue  between  the 
males  for  the  possession  of  some  particular  female,  who 
sits  an  apparently  unconcerned  beholder  of  the  struggle 
for  supremacy,  and,  when  the  victory  is  decided,  quietly 
flies  away  in  company  with  the  conqueroi"."  Westwood  " 
says  that  the  males  of  one  of  the  saw-flies  (Tenthredinte) 
"have  been  found  fighting  together,  with  their  mandibles 
locked."  As  M.  Fabre  speaks  of  the  males  of  Cerceris 
striving  to  obtain  a  particular  female,  it  may  be  well  to 
bear  in  mind  that  insects  belonging  to  this  Order  have  the 
power  of  recognizing  each  other  after  long  intervals  of 
time,  and  are  deeply  attached.  For  instance,  Pierre  Huber, 
whose  accuracy  no  one  doubts,  separated  some  ants,  and 
when  after  an  interval  of  four  months  they  met  others 

'*  Kirby  and  Spence,  'Introduct.  to  Entomology,'  vol.  ii.  1818,  p.  35. 
*^  See  an  interesting  article,  "  The  Writings  of  Fabre,"  in  '  Nat.  Hist, 
Review,'  April,  1862,  p.  122. 

"  'Journal  of  Proc.  of  Entomolog.  Soc.'  Sept.  Y,  1863,  p.  169. 
16 


364  SEXUAL  SELECTION.  [Part  H. 

which  had  formerly  belonged  to  the  same  commiuiity, 
they  mutually  recognized  and  caressed  each  other  with 
their  antennie.  Had  they  been  strangers  they  would  have 
fought  together.  Again,  when  two  communities  engage 
in  a  battle,  the  ants  on  the  same  side  in  the  general  confu- 
sion sometimes  attack  each  other,  but  they  soon  perceive 
their  mistake,  and  tlie  one  ant  soothes  the  other." 

In  this  order  slight  differences  in  color,  according  to 
sex,  are  common,  but  conspicuous  differences  are  rare  ex- 
cept in  the  family  of  Bees ;  yet  both  sexes  of  certain 
groups  are  so  brilliantly  colored — for  instance,  in  Chrysis, 
in  which  vermilion  and  metallic  greens  prevail — that  we 
are  tempted  to  attribute  the  result  to  sexual  selection.  In 
the  Ichneumonidie,  according  to  Mr.  Walsh,"  the  males 
are  almost  universally  lighter  colored  than  the  females. 
On  the  other  hand,  in  the  Tenthredinida?  the  males  are 
generally  darker  than  the  females.  In  the  Siricidse  the 
sexes  frequently  diflfer:  thus  the  male  of  Sirex  juvencxis  is 
banded  with  orange,  while  the  female  is  dark  purple ;  but 
it  is  difficult  to  say  which  sex  is  the  most  ornamented. 
In  Tremex  columhae  the  female  is  much  brighter  colored 
than  the  male.  With  ants,  as  I  am  informed  by  Mr.  F. 
Smith,  the  males  of  several  species  are  black,  the  females 
being  testaceous.  In  the  family  of  Bees,  especially  in 
the  solitary  species,  as  I  hear  from  the  same  distinguished 
entomologist,  the  sexes  often  differ  in  color.  The  males 
are  generally  the  brightest,  and,  in  Bombus  as  well  as  in 
Apathus,  much  moi-e  variable  in  color  than  the  females. 
In  Anthophora  retiisa  the  male  is  of  a  rich  fulvous  brown, 
while  the  female  is  quite  black  :  so  are  the  females  of  sev- 
eral species  of  Xylocopa,  the  males  being  bright  yellow. 
In  an  Australian  bee  [Lestis  homhylans),  the  female  is  of 

"P.    Huber,  'Recherches  sur  les   Moeurs   des   Founnis,'  1810,  pp. 
150,  165. 

S6  'Proc.  Entomolog.  Soc.  of  Pliiladelpliia,'  18G6,  pp.  238,  239. 


Chap.  X.]  HYMENOPTERA.— COLEOPTERA.  355 

an  extremely  brilliant  steel-blue,  sometimes  tinted  with 
vivid  green ;  the  male  being  of  a  bright  brassy  color 
clothed  with  rich  fulvous  pubescence.  As  in  this  group 
the  females  are  pi-ovided  with  excellent  defensive  weap- 
ons in  their  stings,  it  is  not  probable  that  they  have  come 
to  diifer  in  color  from  the  males  for  the  sake  of  protection. 
Mutilla  Europcea  emits  a  stridulating  noise ;  and  ac- 
cording to  Goureau "  both  sexes  have  this  power.  He 
attributes  the  souud  to  the  friction  of  the  third  and  pre- 
ceding abdominal  segments;  and  I  find  that  these  sur- 
faces are  marked  with  very  fine  concentric  ridges,  but  so 
is  the  projecting  thoracic  collar,  on  which  the  head  artic- 
ulates ;  and  this  collar,  when  sci'atched  with  the  point  of 
a  needle,  emits  the  proper  sound.  It  is  rather  surprising 
that  both  sexes  should  have  the  power  of  stridulating,  as 
the  male  is  winged  and  the  female  windless.  It  is  notori- 
ous  that  Bees  express  certain  emotions,  as  of  anger,  by  the 
tone  of  their  humming,  as  do  some  dipterous  insects ;  but 
I  have  not  referred  to  these  sounds,  as  they  are  not  known 
to  be  in  any  way  connected  with  the  act  of  courtship. 

Order,  Goleoptera  (Beetles). — Many  beetles  are  col- 
ored so  as  to  resemble  the  surfaces  which  they  habitually 
frequent.  Other  species  are  ornamented  with  gorgeous 
metallic  tints — for  instance,  many  Carabidge,  which  live 
on  the  ground  and  have  the  power  of  defending  them- 
selves by  an  intensely  acrid  secretion — the  splendid  dia- 
mond-beetles which  are  protected  by  an  extremely  hard 
covering — many  species  of  Chrysomela,  such  as  C.  cere- 
alis,  a  large  species  beautifully  striped  with  various  col- 
ors, and  in  Britain  confined  to  the  bare  summit  of  Snow- 
don — and  a  host  of  other  species.  These  splendid  colors, 
which  are  often  arranged  in  stripes,  spots,  crosses,  and 
other  elegant  patterns,  can  hardly  be  beneficial,  as  a  pro- 

"  Quoted  by  Westwood,  '  Modem  Class,  of  Insects,'  vol.  ii.  p.  214. 


35G  SEXUAL   SELECTION.  [Part  II 

tection,  except  in  the  case  of  some  flower-feeding  species ; 
and  we  cannot  believe  that  they  are  purposeless.  Hence 
the  suspicion  arises  tliat  they  serve  as  a  sexual  attrac- 
tion ;  but  we  have  no  evidence  on  this  head,  for  the  sexes 
rarely  diflfer  in  color.  •  Blind  beetles,  which  cannot  of 
course  behold  each  other's  beauty,  never  exhibit,  as  I  hear 
from  Mr,  Waterhouse,  Jr.,  bright  colors,  though  they 
often  have  polished  coats  :  but  the  explanation  of  their 
obscurity  may  be  that  blind  insects  inhabit  caves  and 
other  obscure  stations. 

Some  Longicorns,  however,  especially  certain  Prioni- 
dce,  offer  an  exception  to  the  common  rule  that  the  sexes 
of  beetles  do  not  difter  in  color.  Most  of  these  insects  are 
large  and  splendidly  colored.  The  males  in  the  genus 
Pyrodes,^'  as  I  saw  in  Mr.  Bates's  collection,  are  generally 
redder  but  rather  duller  than  the  females,  the  latter  being 
colored  of  a  moi'e  or  less  splendid  golden  green.  On  the 
other  hand,  in  one  species  the  male  is  golden  green,  the 
female  being  richly  tinted  with  red  and  purple.  In  the 
genus  Esmeralda  the  sexes  differ  so  greatly  in  color  that 
they  have  been  ranked  as  distinct  species :  in  one  species 
both  are  of  a  beautiful  shining  green,  but  the  male  has  a 

68  pyrodes  pulcherrimus,  in  which  the  sexes  differ  conspicuously,  has 
been  described  by  Mr.  Bates  in  'Transact.  Ent.  Soc'  1869,  p.  50.  I  will 
specify  the  few  other  cases  in  which  I  have  heard  of  a  difl'erence  in  color 
between  the  sexes  of  beetles.  Kirby  and  Spence  ('  Introduct.  to  Ento- 
mology,' vol.  iii.  p.  301)  mention  a  Cantharis,  Meloe,  Rhagium,  and  the 
Leptura  tcstacta  ;  the  male  of  the  latter  being  testaceous,  with  a  black 
thorax,  and  the  female  of  a  dull  red  all  over.  These  two  latter  beetles 
belong  to  the  Order  of  Longicorns.  Messrs.  R.  Trimen  and  Waterhouse, 
Jr.,  inform  me  of  two  Laniellicorns,  viz.,  a  Peritrichia  and  Trichius,  the 
male  of  the  latter  being  more  obscurely  colored  than  the  female.  In 
Tillus  elouffaius  tlie  male  is  black,  and  the  female  always,  as  it  is  believed, 
of  a  dark-blue  color  with  a  red  thorax.  The  male,  also,  of  Orsodacna 
atra,  as  I  hear  from  Mr.  Walsh,  is  black,  the  female  (the  so-called 
0.  ruJicoUis)  having  a  rufous  thorax. 


Chap.  X.] 


COLEOPTERA. 


357 


red  thorax.  On  the  whole,  as  far  as  I  covild  judge,  the 
females  of  those  PrionidiB,  in  which  the  sexes  difler,  are 
colored  more  richly  than  the  males  ;  and  this  does  not  ac- 
cord with  the  common  rule  in  regard  to  color  when  ac- 
quired through  sexual  selection. 


Fig.  15.— Chalcosoma  atlas.    Upper  ficrure,  male  (reduced) ;  lower  figure,  female 
(natural  size). 


A  most  remarkable  distinction  between  the  sexes  of 
many  beetles  is  presented  by  the  great  horns  which  rise 
from  the  head,  thorax,  or  clypeus  of  the  males ;  and  in 
some  few  cases  from  the  under  surface  of  the  body.  These 
horns,  in  the  great  family  of  the  Lamellicorns,  resemble 
those  of  various  quadrupeds,  such  as  stags,  rhinoceroses, 
etc.,  and  are  wonderful  both  from  their  size  and  diversi- 
fied shapes.  Instead  of  describing  them,  I  have  given 
figures  of  the  males  and  females  of  some  of  the  more  re- 
markable  forms.     (Figs.   15    to  19.)      The  females  gen- 


858 


SEXUAL   SELECTION.  [Pabt  II. 


Fig.  10.— Copris  isidis.    (Left-hand  figures,  males.) 


FiQ.  17.— Phanseus  faunas. 


Fio.  18.— Dipelicus  cantorL 


Fig.  19.— OnthophaiTus  rangifer,  enlarged. 


Chap.  X.]  COLEOPTERA.  359 

erally  exhibit  rudiments  of  the  horns  in  the  form  of  small 
knobs  or  ridges ;  but  some  are  destitute  of  even  a  rudi- 
ment. On  the  other  hand,  the  horns  are  nearly  as  well 
developed  in  the  female  as  in  the  male  of  Phanoeus  lan- 
cifer,'  and  only  a  little  less  well  developed  in  the  females 
of  some  other  species  of  the  same  genus  and  of  Copris. 
In  the  several  subdivisions  of  the  family,  the  differences 
in  structure  of  the  horns  do  not  run  parallel,  as  I  am  in- 
formed by  Mr.  Bates,  with  their  more  important  and 
characteristic  differences  ;  thus,  within  the  same  natural 
section  of  the  genus  Onthophagus,  there  are  species  which 
have  either  a  single  cephalic  horn,  or  two  distinct  horns. 

In  almost  all  cases,  the  horns  are  remarkable  from 
their  excessive  variability ;  so  that  a  graduated  series 
can  be  formed,  from  the  most  highly-developed  males  to 
others  so  degenerate  that  they  can  barely  be  distinguished 
from  the  females.  Mr.  Walsh  "  found  that  in  Phanceus 
carnifex  the  horns  were  thrice  as  long  in  some  males  as 
in  others.  Mr.  Bates,  after  examining  above  a  hundred 
males  of  Onthophagus  rangifer  (fig.  19),  thought  that  he 
had  at  last  discovered  a  species  in  which  the  horns  did 
not  vary ;  but  further  research  proved  the  contrary. 

The  extraordinary  size  of  the  horns,  and  their  widely- 
different  structure  in  closely-allied  forms,  indicate  that 
they  have  been  formed  for  some  important  purpose  ;  but 
their  excessive  variability  in  the  males  of  the  same  species 
leads  to  the  inference  that  this  purpose  cannot  be  of  a 
definite  nature.  The  horns  do  not  show  marks  of  fric- 
tion, as  if  used  for  any  ordinary  work.  Some  authors 
suppose  "'  that  as  the  males  wander  much  more  than  the 
females,  they  require  horns  as  a  defence  against  their 
enemies ;  but  in  many  cases  the  horns  do  not  seem  well 
adapted  for  defence,  as  they  are  not  sharp.     The  most 

"  'Proc.  Entomolog.  Soc.  of  Philadelphia,'  1864,  p.  228. 

*"  Kirby  and  Spence,  '  Introduct.  Entomolog.'  vol.  iii.  p.  300. 


3G0  SEXUAL   SELECTION.  [Part  IL 

obvious  conjecture  is  that  they  are  used  by  the  males  for 

fighting  togetlicr ;  but  they  have  never  been  observed  to 
fight ;  nor  could  Mr.  Bates,  after  a  careful  examination  of 
numerous  species,  find  any  sufficient  evidence,  in  their 
mutihited  or  broken  condition,  of  their  having  been  thus 
used.  If  the  males  had  been  habitual  fighters,  their  size 
v/ould  probably  have  been  increased  through  sexual  selec- 
tion, so  as  to  have  exceeded  that  of  the  female ;  but  Mr. 
Bates,  after  comparing  the  two  sexes  in  above  a  hundred 
species  of  the  Copridoe,  does  not  find  in  well-developed  in- 
dividuals any  marked  diflerence  in  this  respect.  There  is, 
moreover,  one  beetle,  belonging  to  the  same  great  divis- 
ion of  the  Lamellicorns,  namely,  Lethrus,  the  males  of 
which  are  known  to  fight,  but  they  are  not  provided  with 
horns,  though  their  mandibles  are  much  larger  than  those 
of  the  female. 

The  conclusion,  which  best  agrees  with  the  fact  of  the 
horns  having  been  so  immensely  yet  not  fixedly  devel- 
oped— as  shown  by  their  extreme  variability  in  the  same 
species  and  by  their  extreme  diversity  in  closely-allied 
species — is  that  tliey  have  been  acquired  as  ornaments. 
This  view  will  at  first  appear  extremely 
improbable;  but  we  shall  hereafter  find 
with  many  animals,  standing  much  higher 
in  the  scale,  namely,  fishes,  amphibians, 
reptiles,  and  birds,  that  various  kinds  of 
crests,  knobs,  horns,  and  combs,  have 
been  developed  apparently  for  this  sole 
purpose. 
Fig.  20.  —  Onitis  fur-        The  malcs  of  Onitis  furcifer  (fig.  20) 

cifer,    male,   viewed  r        -i      ^        '.i         •      'i       '  •    „t.i „ 

from  beneath.  'ii'c  lumished  With   SHigular   projections 

on  their  anterior  femora,  and  with  a  great 

fork  or  pair  of  horns  on  the  lower  surface  of  the  thorax. 

This  situation  seems  extremely  ill-adapted  for  the  display 

of  these  projections,  and  they  may  be  of  some  real  service ; 


Chap.  X.]  COLEOPTERA.  361 

but  no  use  can  at  present  be  assigned  to  them.  It  is  a 
highly-remarkable  fact,  that  although  the  males  do  not  ex- 
hibit even  a  trace  of  horns  on  the  upper  surface  of  the 
body,  yet  in  the  females  a  rudiment  of  a  single  horn  on  the 
head  (fig.  21,  a),  and  of  a  crest  [b)  on  the  thorax,  are  plainly 
visible.     That  the   slightest  thoracic  crest  in  the  female 


Fig.  21.— Left-hand  figure,  male  of  Onitis  furcifer,  viewed  laterally.  Eight-hand 
figure,  female,  a.  Rudiment  of  cephalic  horn.  b.  Trace  of  thoracic  horn  or 
crest. 

is  a  rudiment  of  a  projection  proper  to  the  male,  though 
entirely  absent  in  the  male  of  this  particular  species,  is 
clear  :  for  the  female  of  JBuhas  bison  (a  form  which  comes 
next  to  Onitis)  has  a  similar  slight  crest  on  the  thorax, 
and  the  male  has  in  the  same  situation  a  great  projection. 
So  again  there  can  be  no  doubt  that  the  little  point  (a) 
on  the  head  of  the  female  Onitis  furcifer,  as  well  of  the 
females  of  two  or  three  allied  species,  is  a  rudimentary 
representative  of  the  cephalic  horn,  which  is  common  to 
the  males  of  so  many  lamellicorn  beetles,  as  in  Phaneeus, 
fig.  17.  The  males,  indeed,  of  some  unnamed  beetles  in 
the  British  Museum,  which  are  believed  actually  to  be- 
long to  the  genus  Onitis,  are  furnished  with  a  similar 
horn.  The  remarkable  nature  of  this  case  will  be  best 
perceived  by  an  illustration  :  the  Ruminant  quadrupeds 
run  parallel  with  the  lamellicorn  beetles,  in  some  females 
possessing  horns  as  large  as  those  of  the  male,  in  others 
having  them  much  smaller,  or  existing  as  mere  rudiments 
(though  this  is  as  rare  with  ruminants  as  it  is  common 


362  SEXUAL  SELECTION  [Pakt  H. 

with  Lamellicorns),  or  in  having  none  at  all.  Now,  if  a 
new  species  of  deer  or  sheep  were  discovered  with  the 
female  bearing  distinct  rudiments  of  horns,  while  the 
head  of  tlie  male  was  absolutely  smooth,  we  should  have 
a  case  like  that  of  Onitis  furcifer. 

In  this  case  the  old  belief  of  rudiments  having  been 
created  to  complete  the  scheme  of  Nature  is  so  far  from 
holding  good,  that  all  ordinary  rules  are  completely 
broken  through.  The  view  which  seems  the  most  proba- 
ble is  that  some  early  progenitor  of  Onitis  acquired,  like 
other  Lamellicorns,  horns  on  the  head  and  thorax,  and  then 
transferred  them,  in  a  rudimentary  condition,  as  with  so 
many  existing  species,  to  the  female,  by  whom  they  have 
ever  since  been  retained.  The  subsequent  loss  of  the 
horns  by  the  male  may  have  resulted  through  the  prin- 
ciple of  compensation  from  the  development  of  the  pro- 
jections on  the  lower  surface,  while  the  female  has  not 
been  thus  affected,  as  she  is  not  furnished  with  these  pro- 
jections, and  consequently  has  retained  the  rudiments  of 
the  horns  on  the  upper  surface.  Although  this  view  is 
supported  by  the  case  of  Bledius  immediately  to  be  given, 
yet  the  projections  on  the  lower  surface  differ  greatly  in 
structure  and  development  in  the  males  of  the  several  spe- 
cies of  Onitis,  and  are  even  rudimentary  in  some ;  never- 
theless the  upper  surface  in  all  these  species  is  quite  desti- 
tute of  horns.  As  secondary  sexual  characters  are  so  emi- 
nently variable,  it  is  possible  that  the  projections  on  the 
lower  surface  may  have  been  first  acquired  by  some  "pro- 
genitor of  Onitis  and  produced  their  effect  through  com- 
pensation, and  then  have  been  in  certain  cases  almost 
completely  lost. 

All  the  cases  hitherto  given  refer  to  the  Lamellicorns, 
but  the  remains  of  some  few  other  beetles,  belonging  to 
two  widely-distinct  groups,  namely,  the  Curculionida^  and 
Staphylinidw,  are  furnished  with  horns — in  the  former  on 


Chap.  X.]  COLEOPTERA.  363 

the  lower  surface  of  the  body,"  in  the  latter  on  the  upper 
surface  of  the  head  and  thorax.  In  the  Staphylinidae  the 
horns  of  the  males  in  the  same  species  are  extraordinarily 
variable,  just  as  we  have  seen  with  the  Lamellicorns.     In 


Fig.  22.— Bledius  tauras,  magnified.    Left-hand  figure,  male ;  right-hand  figure, 

female. 

Siagonium  we  have  a  case  of  dimorphism,  for  the  males 
can  be  divided  into  two  sets,  differing  greatly  in  the  size 
of  their  bodies,  and  in  the  development  of  their  horns, 
without  any  intermediate  gradations.  In  a  species  of 
Bledius  (fig.  22),  also  belonging  to  the  Staphylinidae,  male 
specimens  can  be  found  in  the  same  locality,  as  Prof. 
"Westwood  states,  "in  which  the  central  horn  of  the  tho- 
rax is  very  large,  but  the  horns  of  the  head  quite  rudi- 
mental;  and  others,  in  which  the  thoracic  horn  is  much 
shorter,  while  the  protuberances  on  the  head  are  long."  " 
Here,  then,  we  apparently  have  an  instance  of  compensa- 
tion of  gi'owth,  which  throws  light  on  the  curious  case 
just  given  of  the  loss  of  the  upper  horns  by  the  males  of 
Onitis  farcifer. 

Law  of  Battle. — Some  male  beetles,  which  seem  ill 
fitted  for  fighting,  nevertheless  engage  in  conflicts  for  the 
possession  of  the  females.  Mr.  Wallace  "  saw  two  males 
of  Leptorhynchus  angustatus,  a  linear  beetle  with  a  much 

*•  Kirby  and  Spence,  iliid.  vol.  iii.  p.  329. 

'^  'Modern  Classification  of  Insects,'  vol.  i.  p.  1*72.  On  the  same  page 
there  is  an  account  of  Siagonium.  In  the  British  Museum  I  noticed  one 
male  specimen  of  Siagonium  in  an  intermediate  condition,  so  that  the 
dimorphism  is  not  strict. 

«»  'The  Malay  Archipelago,'  vol.  ii.  1869,  p.  278. 


3G4  SEXUAL   SELECTION.  [Part  IL 

elongated  rostrum,  "  fighting  for  a  female,  who  stood  close 
by  busy  at  licr  boring.  They  pushed  at  each  other  with 
their  rostra,  and  clawed  and  thumped  apparently  in  the 
greatest  rage."  The  smaller  male,  however,  "  soon  ran 
away,  acknowledging  himself  vanquished."  In  some  few 
cases  the  males  are  well  adapted  for  fighting,  by  possess- 
ing great  toothed  mandibles,  much  larger  than  those  of  the 
females.  This  is  the  case  with  the  common  stag-beetle 
{Liicanus  cervus),  the  males  of  which  emerge  from  the 
pupal  state  about  a  week  before  the  other  sex,  so  that 
several  may  often  be  seen  pursuing  the  same  female.  At 
this  period  they  engage  in  fierce  conflicts.  When  Mr.  A. 
H.  Davis  "  enclosed  two  males  with  one  female  in  a  box, 
the  larger  male  severely  pinched  the  smaller  one,  until  he 
resigned  his  pretensions.  A  friend  informs  me  that  when 
a  boy  he  often  put  the  males  together  to  see  them  fight, 
and  he  noticed  that  they  were  much  bolder  and  fiercer 
than  the  females,  as  is  well  known  to  be  the  case  with  the 
higher  animals.  The  males  would  seize  hold  of  his  finger, 
if  held  in  front,  but  not  so  the  females.  With  many 
of  the  Lucanida3,  as  well  as  with  the  above-mentioned 
Leptorhynchus,  the  males  are  larger  and  more  powerful 
insects  than  the  females.  The  two  sexes  of  Lethrus 
cephalotes  (one  of  the  Lamellicorns)  inhabit  the  same  bur- 
row ;  and  the  male  has  larger  mandibles  than  the  female. 
If,  during  the  breeding-season,  a  strange  male  attempts  to 
enter  the  burrow,  he  is  attacked  ;  the  female  does  not  re- 
main passive,  but  closes  the  mouth  of  the  burrow,  and  en- 
courages her  mate  by  continually  pushing  him  on  from 
behind.  The  action  does  not  cease  until  the  aggressor  is 
killed  or  runs  away."     The  two  sexes  of  another  lamelli- 


«*  '  Entomological  Magazine,'  vol.  i.  1833,  p.  82.  See  also,  on  the  con- 
flicts of  this  species,  Kirby  andSpcnce,  ibid.  vol.  iii.  p.  314  ;  and  West- 
wood,  ibid.  vol.  i.  p.  187. 

*°  Quoted  from  Fischer,  in  '  Diet.  Class.  d'Hist.  Nat.'  torn.  x.  p.  324. 


Chap.  X.]  COLEOPTERA.  365 

corn  beetle,  the  Ateuchus  cicatricosus,  live  in  pairs,  and 
seem  much  attached  to  each  other ;  the  male  excites  the 
female  to  roll  the  balls  of  dung  in  which  the  ova  are  de- 
posited ;  and,  if  she  is  removed,  he  becomes  much  agita- 
ted. If  the  male  is  removed,  the  female  ceases  all  work, 
and,  as  M.  Brulerie  "  believes,  would  remain  on  the  spot 
until  she  died. 

The  great  mandibles  of  the  male  Lucanidae  are  ex- 
tremely variable  both  in  size  and  structure,  and  in  this 
respect  resemble  the  horns  on  the  head  and  thorax  of 
many  male  Lamellicoms  and  Staphylinidse.  A  perfect 
series  can  be  formed  from  the  best-provided  to  the  worst- 
provided  or  degenerate  males.  Although  the  mandibles 
of  the  common  stag-beetle,  and  probably  of  many  other 
species,  are  used  as  efficient  weapons  for  fighting,  it  is 
doubtful  whether  their  great  size  can  thus  be  accounted 
for.  We  have  seen  that  with  the  Lucanus  elaphus  of 
North  America  they  are  used  for  seizing  the  female.  As 
they  are  so  conspicuous  and  so  elegantly  branched,  the 
suspicion  has  sometimes  crossed  my  mind  that  they  may 
be  serviceable  to  the  males  as  an  ornament,  in  the  same 
manner  as  the  horns  on  the  head  and  thorax  of  the 
various  above-described  species.  The  male  Ghiasognathus 
grantii  of  South  Chili — a  splendid  beetle  belonging  to  the 
same  family — has  enormously-developed  mandibles  (fig. 
23) ;  he  is  bold  and  pugnacious;  when  threatend  on  any 
side  he  faces  round,  opening  his  great  jaws,  and  at  the 
same  time  stridulating  loudly;  but  the  mandibles  were 
not  strong  enough  to  pinch  my  finger  so  as  to  cause 
actual  pain. 

Sexual  selection,  which  implies  the  possession  of  con- 
siderable perceptive  powers  and  of  strong  passions,  seems 
to  have  been  more  efiective  with  the  Lamellicoms  than 

^*  '  Ann.  Soc.  Eutomolog.  France,'  1866,  as  quoted  in  '  Journal  of 
Travel,'  by  A.  Murray,  1868,  p.  135. 


8UG- 


SEXUAL  SELECTION. 


[Part  II. 


with  any  other  family  of  the  Coleoptera  or  beetles.  With 
some  species  the  males  are  provided 
with  weapons  ior  lightmg ;  some  live 
in  i^airs  and  show  mutual  afiection  • 
many  have  the  power  of  stridulating 
when  excited  ;  many  are  furnished 
with  the  most  extraordinary  horns, 
apparently  for  the  sake  of  ornament ; 
some  which  are  diurnal  in  their  hab- 
its are  gorgeously  colored ;  and,  last- 
ly, several  of  the  largest  beetles  in 
the  world  belong  to  this  family,  which 
w^as  placed  by  Linnaeus  and  Fabri- 
cius  at  the  head  of  the  Order  of  the 
Coleoptera." 


Stridulating  organs.  —  Beetles 
belonging  to  many  and  widely-dis- 
tinct families  possess  these  organs. 
The  sound  can  sometimes  be  heard 
at  the  distance  of  several  feet  or  even 
yards,"  but  is  not  comparable  with 
tliat  produced  by  the  Orthoptera. 
The  part  which  may  be  called  the 
rasp  generally  consists  of  a  narrow 
slightly-raised  surface,  crossed  by 
very  fine,  parallel  ribs,  sometimes  so 
fine  as  to  cause  iridescent  colors,  and 
having  a  very  elegant  appearance 
under  the  microscope.  In  some  cases, 
for  instance,  Avith  Typhncus,  it  could 
be  plainly   seen  that  extremely  mi- 


!.  —  Chiasogiiathns 
i,  reduced.  Upper 
male ;  lower  figure. 


*'  Wcstwood,  'Modem  Class.'  vol.  i.  \i.  184. 

^*  Wollaston,  On  certain  musical  Curculionidee,  '  Annals  and  Mag.  of 
Kat.  Hist.'  vol.  vi.  1860,  p.  14. 


Chap.  X.] 


COLEOPTERA. 


367 


nute,  bristly,  scale-like  prominences,  which  cover  the 
whole  surrounding  surface  in  approximately  parallel  lines 
give  rise  to  the  ribs  of  the  rasp  by  becoming  confluent 
and  straight,  and  at  the  same  time  more  prominent  and 
smooth.  A  hard  ridge  on  any  adjoinhig  part  of  the  body, 
which  in  some  cases  is  specially  modified  for  the  pur- 
pose, serves  as  the  scraper  for  the  rasp.  The  scraper  is 
rapidly  moved  across  the  rasp,  or  conversely  the  rasp 
across  the  scraper. 

These  organs  are  situated  in  widely-different  positions. 
In  the  carrion-beetles  (Necrophorus)  two  parallel  rasps  (r, 
fig.  24)  stand  on  the  dorsal  surface  of  the  fifth  abdominal 


Fig.  24— Necrophorus  (from  Landois)     r.  The  two  rasps.  Left-hand  figure,  part 
of  the  rasp  highly  magnified. 

segment,  each  rasp  being  crossed,  as  described  by  Lan- 
dois," by  from  126  to  140  fine  ribs.  These  ribs  are 
scraped  by  the  posterior  margins  of  the  elytra,  a  small 
portion  of  which  projects  beyond  the  general  outline.  In 
many  Crioceridfe,  and  in  Clythra  ^-punctata  (one  of  the 
Chrysomelidoe),  and  in  some  Tenebrionida?,  etc.,"  the  rasp 

«'  'Zeitschrift  fiir  wiss.  Zoolog.'  B.  xvii.  1867,  s.  127. 

■"•  I  am  greatly  indebted  to  Mr.  G.  E.  Crotch  for  having  sent  me  nu- 
merous prepared  specimens  of  various  beetles  belonging  to  these  three 
families  and  others,  as  well  as  for  valuable  information  of  all  kinds.  He 
believes  that  the  power  of  stridulation  in  the  Clythra  has  not  been  pre- 
viously observed.  I  am  also  much  indebted  to  Mr.  E.  W.  Janson,  for 
information  and  specimens.    I  may  add  that  my  son,  Mr.  F.  Darwin,  finds 


3G8  SEXUAL   SELECTION.  [Part  n. 

is  seated  on  the  dorsal  apex  of  the  abdomen,  on  the  py- 
gidiura  or  pro-pygidium,  and  is  scraped  as  above  by  the 
elytra.  In  Heterocerus,  which  belongs  to  another  family, 
the  rasps  are  placed  on  the  sides  of  the  first  abdominal 
segment,  and  are  scraped  by  ridges  on  the  femora."  In 
certain  Curculionidje  and  Carabidoe,"  the  parts  are  com- 
pletely reversed  in  position,  for  the  rasps  are  seated  on  the 
inferior  surface  of  the  elytra,  near  their  apices,  or  along 
their  outer  margins,  and  the  edges  of  the  abdominal  seg- 
ments serve  as  the  scrapers.  In  Pelohius  hermanni  (one 
of  Dytiscida3  or  water-beetles)  a  strong  ridge  runs  parallel 
and  near  to  the  sutux-al  margin  of  the  elytra,  and  is 
crossed  by  ribs,  coarse  in  the  middle  part,  but  becoming 
gradually  finer  at  both  ends,  especially  at  the  upper  end ; 
when  this  insect  is  held  under  water  or  in  the  air,  a  strid- 
ulating  noise  is  produced  by  scraping  the  extreme  horny 
margin  of  the  abdomen  against  the  rasp.  In  a  great  num- 
ber of  long-horned  beetles  (Longicornia)  the  organs  are 
altogether  differently  situated,  the  rasp  being  on  the 
meso-thorax,  which  is  rubbed  against  the  pro-thorax; 
Landois  counted  238  very  fine  ribs  on  the  rasp  of  Ceramr 
byx  heros. 

Many  Lamellicorns  have  the  power  of  stridulating, 
and  the  organs  differ  greatly  in  position.  Some  species 
stridulate  very  loudly,  so  that  when  Mr.  F.  Smith  caught 

that  Dcrmcsies  murhiiis  stridulates,  but  he  searched  in  vain  for  the  appa- 
ratus. Scolytus  has  lately  been  described  by  Mr.  Algen  as  a  stridulator, 
in  the  'Edinburgh  Monthly  Magazine,'  1869,  Nov.,  p.  130. 

'•  SchiiJdte,  translated  in  '  Annals  and  Mag.  of  Nat.  Hist.'  vol.  xx. 
1867,  p.  37. 

'*  Westringhas  described  (Kroyer,  'Naturhist.  Tidskrift,'  B.  ii.  1848- 
'49,  p.  334)  the  stridulating  organs  in  these  two,  as  well  as  in  other  fam- 
ilies. In  the  Carabidye  I  have  examined  Elaphrus  ^tUginoxus  athA  BIcthisa 
multipundata,  sent  to  me  by  Mr.  Crotch.  In  Blethisa  the  transverse 
ridges  on  the  furrowed  border  of  the  abdominal  segment  do  not  come 
into  play,  as  far  as  I  could  judge,  in  scraping  the  rasps  on  the  elytra. 


Chap.  X.] 


COLEOPTERA. 


369 


a  Trox  sahulosus,  a  gamekeeper  who  stood  by  thought  that 
he  had  caught  a  mouse ;  but  I  failed  to  discover  the  proper 
organs  in  this  beetle.  In  Geotrupes  and  Typhseus  a  nar- 
now  ridge  runs  obliquely  across  (r,  fig.  25)  the  coxa  of 
each  hind-leg,  having  in  G.  stercorarlus  eighty-four  ribs, 
which  are  scraped  by  a  specially  projecting 
part  of  one  of  the  abdominal  segments.  In 
the  nearly-allied  Cop7'is  lunaris,  an  exces- 
sively narrow  fine  rasp  runs  along  the  sutu- 
ral  margin  of  the  elytra,  with  another  short 
rasp  near  the  basal  outer  margin  ;  but  in 
some  other  Coprini  the  rasp  is  seated,  ac- 
cording to  Leconte,"  on  the  dorsal  surface  of 
the  abdomen.  In  Oryctes  it  is  seated  on 
the  pro-pygidium,  and  in  some  other  Dy- 
nastini,  according  to  the  same  entomolo- 
gist, on  the  under  surface  of  the  elytra.  ^^ 
Lastly,  Westring  states  that  in  Omaloplia   Fig.  25.— Hind-leg 

,  ,  -IT  .1  of  Geotrupes  ster- 

brunnea   the   rasp   is   placed    on   the  pro-      corarUis     (from 
sternum,   and    the   scraper    on   the   meta- 

,  ,  r.  Rasp.    c.  Coxa. 

sternum,   the   parts    thus    occupymg    the     /.  Femur.  <.  Tibia. 
under  surface  of  the  body,  instead  of  the 
upper  surface  as  in  the  Longicorns. 

We  thus  see  that  the  stridulating  organs  in  the  difier- 
ent  coleopterous  families  are  wonderfully  diversified  in 
position,  but  not  much  in  structure.  Within  the  same 
family  some  species  are  provided  with  these  organs,  and 
some  are  quite  destitute  of  them.  This  diversity  is  intelli- 
gible, if  we  suppose  that  originally  various  species  made 
a  shuffling  or  hissing  noise  by  the  rubbing  together  of  the 
hard  and  rough  parts  of  their  bodies  Avhich  were  in  con- 
tact ;  and  that,  from  the  noise  thus  produced  being  in 
some  way  useful,  the  rough  surfaces  were  gradually  de- 

■"  I  am  indebted  to  Mr.  Walsh,  of  Illinois,  for  having  sent  me  extracts 
from  Leconte's  'Introduction  to  Entomology,'  pp.  101,  143. 


370  SEXUAL   SELECTION.  [Part  IL 

veloped  into  regular  stridulating  organs.  Some  beetles,  as 
they  move,  now  produce,  either  intentionally  or  uninten- 
tionally, a  shuffling  noise,  without  possessing  any  proper 
organs  for  the  purpose.  Mr.  Wallace  informs  me  that  the 
Muchirus  longi7nanus  (a  Lamellicorn,  w^th  the  anterior 
legs  wonderfully  elongated  in  the  male)  "  makes,  while 
moving,  a  low  hissing  sound  by  the  protrusion  and  con- 
traction of  the  abdomen ;  and  when  seized  it  produces  a 
grating  sound  by  rubbing  its  hind-legs  against  the  edges 
of  the  elytra."  The  hissing  soaind  is  clearly  due  to  a 
narrow  rasp  running  along  the  sutural  margin  of  each 
elytron;  and  I  could  likewise  make  the  grating  sound  by 
rubbing  the  shagreened  surface  of  the  femur  against  the 
granulated  margin  of  the  corresponding  elytron;  but  I 
could  not  here  detect  any  proper  rasp ;  nor  is  it  likely 
that  I  could  have  overlooked  it  in  so  large  an  insect. 
After  examining  Cychrus  and  reading  what  "VVestring  has 
written  in  his  two  papers  about  this  beetle,  it  seems  very 
doubtful  whetlier  it  possesses  any  true  rasp,  though  it  has 
the  power  of  emitting  a  sound. 

From  the  analogy  of  the  Orthoptera  and  Homoptera, 
I  expected  to  find  that  the  stridulating  organs  in  the 
Coleoptera  differed  according  to  sex ;  but  Landois,  who 
has  carefully  examined  several  species,  observed  no  such 
difference  ;  nor  did  Westring ;  nor  did  Mr.  G.  R.  Crotch 
in  preparing  the  numerous  specimens  which  he  had  the 
kindness  to  send  me  for  examination.  Any  slight  sexual 
difference,  however,  would  be  difficult  to  detect,  on  ac- 
count of  the  great  variability  of  these  organs.  Thus,  in 
the  first  pair  of  the  JVecrophorus  humator  and  of  the 
JPelobius  which  I  examined,  the  rasp  was  considerably 
larger  in  the  male  than  in  the  female ;  but  not  so  with 
succeeding  specimens.  In  Geotriipes  stercorarius  the  rasp 
appeared  to  me  thicker,  opaquer,  and  more  prominent  in 
three  males  than  in  the  same  number  of  females ;  conse- 


CuAP.  X.]  COLEOPTERA.  371 

quently  my  son,  Mr.  F.  Darwin,  in  order  to  discover 
whether  the  sexes  differed  in  their  power  of  stridulating, 
collected  fifty-seven  living  specimens,  which  he  separated 
into  two  lots,  according  as  they  made,  when  held  in  the 
same  manner,  a  greater  or  lesser  noise.  He  then  examined 
their  sexes,  but  found  that  the  males  were  very  nearly  in 
the  same  proportion  to  the  females  in  both  lots.  Mr.  F. 
Smith  has  kept  alive  numerous  specimens  of  Mononychus 
pseudacori  (Curculionidoe),  and  is  satisfied  that  both  sexes 
stridulate,  and  apparently  in  an  equal  degree. 

Nevertheless  the  power  of  stridulating  is  certainly  a 
sexual  character  in  some  few  Coleoptera.  Mr.  Crotch  has 
discovered  that  the  males  alone  of  two  species  of  Helio- 
pathes  (Tenebrionidse)  possess  stridulating  organs.  I  ex- 
amined five  males  of  H.  gibbus,  and  in  all  these  there  was 
a  well-developed  rasp,  partially  divided  into  two,  on  the 
dorsal  surface  of  the  terminal  abdominal  segment ;  while 
in  the  same  number  of  females  there  was  not  even  a  rudi- 
ment of  the  rasp,  the  membrane  of  this  segment  being 
transparent  and  much  thinner  than  in  the  male.  In  S. 
cribratostriatus  the  male  has  a  similar  rasp,  excepting 
that  it  is  not  partially  divided  into  two  portions,  and  the 
female  is  completely  destitute  of  this  organ ;  but  in  addi- 
tion the  male  has  on  the  apical  margins  of  the  elytra,  on 
each  side  of  the  suture,  three  or  four  short  longitudinal 
ridges,  which  are  crossed  by  extremely  fine  ribs,  parallel 
to  and  resembling  those  on  the  abdominal  rasp ;  whether 
these  ridges  serve  as  an  independent  rasp,  or  as  a  scraper 
for  the  abdominal  rasp,  I  could  not  decide ;  the  female 
exhibits  no  trace  of  this  latter  structure. 

Again,  in  three  species  of  the  Lamellicorn  genus 
Oryctes,  we  have  a  nearly  parallel  case.  In  the  females 
of  0.  gryphus  and  nasieornis  the  ribs  on  the  rasp  of  the 
pro-pygidium  are  less  continuous  and  less  distinct  than  in 
the  males ;  but  the  chief  difference  is  that  the  whole  upper 


372  SEXUAL   SELECTION.  [Part  H. 

surface  of  this  segment,  when  held  in  the  proper  light,  is 
seen  to  be  clothed  with  hairs,  wliich  are  absent  or  are  rep- 
resented by  excessively  fine  down  in  the  males.  It  should 
be  noticed  that,  in  all  Coleoptera,  the  eflfective  part  of  the 
rasp  is  destitute  of  hairs.  In  0.  senegalensis  the  differ- 
ence between  the  sexes  is  more  strongly  marked,  and  this 
is  best  seen  when  the  proper  segment  is  cleaned  and 
viewed  as  a  transparent  object.  In  the  female  the  whole 
surface  is  covered  with  little  separate  crests,  bearing 
spines  ;  while  in  the  male  these  crests  become,  in  proceed- 
ing toward  the  apex,  more  and  more  confluent,  regular, 
and  naked  ;  so  that  three-fourths  of  the  segment  is  covered 
with  extremely  fine  parallel  ribs,  which  are  quite  absent 
in  the  female.  In  the  females,  however,  of  all  three  spe- 
cies of  Oryctes,  when  the  abdomen  of  a  softened  specimen 
is  pushed  backward  and  forward,  a  slight  grating  or  strid- 
ulating  sound  can  be  produced. 

In  the  case  of  the  Heliopathes  and  Oryctes  there  can 
hardly  be  a  doubt  that  the  males  stridulate  in  order  to 
call  or  to  excite  the  females  ;  but  with  most  beetles  the 
stridulation  apparently  serves  both  sexes  as  a  mutual  call. 
This  view  is  not  rendered  improbable  from  beetles  stridu- 
lating  under  various  emotions ;  we  know  that  birds  use 
their  voices  for  many  jDurposes  besides  singing  to  their 
mates.  The  great  Chiasognathus  stridulates  in  anger  or 
defiance ;  many  species  do  the  same  from  distress  or  fear, 
when  held  so  that  they  cannot  escape :  Messrs.  Wollaston 
and  Crotch  were  able,  by  striking  the  hollow  stems  of 
trees  in  the  Canary  Islands,  to  discover  the  presence  of 
beetles  belonging  to  the  genus  Acalles  by  their  stridula- 
tion. Lastly,  the  male  Atcuchus  stridulates  to  encourage 
the  female  in  her  work,  and  from  distress  when  she  is  re- 
moved."    Some  naturalists  believe  that  beetles  make  this 

"*  M.  P.  de  la  Brulerie,  as  quoted  in  '  Journal  of  Travel,'  A.  Murray, 
vol.  i.  1868,  p.  laS. 


Chap.  X.]  COLEOPTERA.  3V3 

noise  to  frighten  away  their  enemies ;  but  I  cannot  think 
that  the  quadrupeds  and  birds  which  are  able  to  devour 
the  larger  beetles,  with  their  extremely  hard  coats,  would 
be  frightened  by  so  slight  a  grating  sound.  The  belief 
that  the  stridulation  serves  as  a  sexual  call  is  supported 
by  the  fact  that  death-ticks  {Anohiura  tesselatum)  are  well 
known  to  answer  each  other's  ticking,  or,  as  I  have  my- 
self observed,  a  tapping  noise  artificially  made ;  and  Mr. 
Doubleday  informs  me  that  he  has  twice  or  thrice  ob- 
served a  female  ticking,"  and  in  the  course  of  an  hour  or 
two  has  found  her  united  with  a  male,  and  on  one  occa- 
sion surrounded  by  several  males.  Finally,  it  seems 
probable  that  the  two  sexes  of  many  kinds  of  beetles  were 
at  first  enabled  to  find  each  other  by  the  slight  shuffling 
noise  produced  by  the  rubbing  together  of  the  adjoining 
parts  of  their  hard  bodies  ;  and  that  as  the  males  or 
females  which  made  the  greatest  noise  succeeded  best  in 
finding  partners,  the  rugosities  on  various  parts  of  their 
bodies  were  gradually  developed  by  means  of  sexual  se- 
lection into  true  stridulating  organs. 

■•'  Mr.  Doubleday  informs  me  that  "  the  noise  is  produced  by  the  in- 
sect raising  itself  on  its  legs  as  high  as  it  can,  and  then  striking  its  thorax 
five  or  six  times,  in  rapid  succession,  against  the  substance  upon  which 
it  is  sitting."  For  references  on  this  subject  see  Landois,  '  Zeitschrift 
fUr  wissen.  Zoolog.'  B.  xvii.  s.  131.  Olivier  says  (as  quoted  by  Kirby  and 
Spence,  '  Introduct.'  vol.  ii.  p.  395)  that  the  female  of  Fimelia  striata 
produces  a  rather  loud  sound  by  striking  her  abdomen  against  any  hard 
substance,  "  and  that  the  male,  obedient  to  this  call,  soon  attends  her, 
and  they  pair." 


374  SEXUAL  SELECTION.  [Part  IL 


CHAPTER  XI. 

INSECTS,  continued. — order  lepidopteea. 

Courtslup  of  Butterflies. —  Battles. —  Ticking  Noise. — Colors  common  to 
Both  Sexes,  or  more  brilliant  in  the  Males. — Examples. — Not  due  to 
the  Direct  Action  of  the  Conditions  of  Life. — Colors  adapted  for  Pro- 
tection.— Colors  of  Moths. — Display. — Perceptive  Powers  of  the  Lepi- 
doptera. — Variability. — Causes  of  the  Diiference  in  Color  between 
the  Males  and  Females. — Mimicry,  Female  Butterflies  more  brilliantly 
colored  than  the  Males. —  Bright  Colors  of  Caterpillars. — Summary 
and  Concluding  Eemarks  on  the  Secondary  Sexual  Characters  of  In- 
sects.— Birds  and  Insects  compared. 

In  this  great  Order  the  most  interesting  point  for  us  is 
the  difference  in  color  between  the  sexes  of  the  same  spe- 
cies, and  between  the  distinct  species  of  the  same  genus. 
Nearly  the  whole  of  the  following  chapter  will  be  devoted 
to  this  subject ;  but  I  will  first  make  a  few  remarks  on  one 
or  two  other  points.  Several  males  may  often  be  seen 
pursuing  and  crowding  round  the  same  female.  Their 
courtship  appears  to  be  a  prolonged  affair,  for  I  have  fre- 
(juently  watched  one  or  more  males  pirouetting  round  a 
female  until  I  became  tired,  without  seeing  the  end  of  the 
courtship.  Although  butterflies  are  such  weak  and  fragile 
creatures,  they  are  pugnacious,  and  an  Emperor  butterfly ' 
has  been  captured  with  the  tips  of  its  wings  broken  from 

*  Apatura  Iris:  'The  Entomologist's  Weekly  Intelligencer,'  1859,  p. 
139.  For  the  Borneau  Butterflies,  see  C.  Collingwood,  '  Rambles  of  a 
Naturalist,'  1868,  p.  183. 


Chap.  XL]  BUTTERFLIES   AND   MOTHS.  375 

a  conflict  with  another  male.  Mr.  Collingwood,  in  speak- 
ing of  the  frequent  battles  between  the  butterflies  of  Bor- 
neo, says,  "  They  whirl  round  each  other  with  the  greatest 
rapidity,  and  appear  to  be  incited  by  the  greatest  ferocity." 
One  case  is  known  of  a  butterfly,  namely,  the  Ageronia 
feronia,  which  makes  a  noise  like  that  produced  by  a 
toothed  wheel  passing  under  a  spring-catch,  and  which 
could  be  heard  at  the  distance  of  several  yards.  At  Rio  de 
Janeiro  this  sound  was  noticed  by  me,  only  when  two 
were  chasing  each  other  in  an  irregular  course,  so  that  it  is 
probably  made  during  the  courtship  of  the  sexes  ;  but  I 
neglected  to  attend  to  this  point.' 

Every  one  has  admired  the  extreme  beauty  of  many 
butterflies  and  of  some  moths  ;  and  we  are  led  to  ask,  How 
has  this  beauty  been  acquired  ?  Have  their  colors  and 
diversified  patterns  simply  resulted  from  the  direct  action 
of  the  physical  conditions  to  which  these  insects  have  been 
exposed,  without  any  benefit  being  thus  derived?  Or 
have  successive  variations  been  accumiilated  and  deter- 
mined either  as  a  protection  or  for  some  unknown  purpose, 
or  that  one  sex  might  be  rendered  attractive  to  the  other  ? 
And,  agam,  what  is  the  meaning  of  the  colors  being  wide- 
ly difierent  in  the  males  and  females  of  certain  species, 
and  alike  in  the  two  sexes  of  other  species  ?  Before  at- 
tempting to  answer  these  questions  a  body  of  facts  must 
be  given. 

With  most  of  our  English  butterflies,  both  those  which 
are  beautiful,  such  as  the  admiral,  peacock,  and  painted 
lady  (Vanessse),  and  those  which  are  plain-colored,  such 
as  the  meadow-browns  (Hipparchise),  the  sexes  are  alike. 
This  is  also  the  case  with  the  magnificent  Heliconidae  and 

*  See  my  '  Journal  of  Researches,'  1845,  p.  33.  Mr.  Doubleday  has 
detected  ('Proc.  Ent.  Soc'  March  3,  1845,  p.  123)  a  peculiar  mem- 
branous sac  at  the  base  of  the  front  wings,  which  is  probably  connected 
with  the  production  of  the  sound. 


37G  SEXUAL   SELECTION.  [Part  IL 

Danaidse  of  the  tropics.  But  in  certain  other  tropical 
groups,  and  with  some  of  our  English  butterflies,  as  the 
purple  emperor,  orange-tip,  etc.  [Apatura  Iris  and  An- 
thocharis  cardamines),  the  sexes  differ  either  greatly  or 
slightly  in  color.  No  language  suffices  to  describe  the 
splendor  of  tlie  males  of  some  tropical  species.  Even 
within  the  same  genus  we  often  find  species  presenting  an 
extraordinary  difierence  between  the  sexes,  while  others 
have  their  sexes  closely  alike.  Thus  in  the  South  Ameri- 
can genus  Epicalia,  Mr.  Bates,  to  whom  I  am  much  in- 
debted for  most  of  the  following  facts  and  for  looking  over 
this  whole  discussion,  informs  me  that  he  knows  twelve 
species,  the  two  sexes  of  which  haunt  the  same  stations 
(and  this  is  not  always  the  case  with  butterflies),  and 
therefore  cannot  have  been  differently  affected  by  external 
conditions.'  In  nine  of  these  species  the  males  rank  among 
the  most  brilliant  of  all  butterflies,  and  diftor  so  greatly 
from  the  comparatively  plain  females  that  they  were  for- 
merly placed  in  distinct  genera. — The  females  of  these 
nine  species  resemble  each  other  in  their  general  type  of 
coloration,  and  likewise  resemble  both  sexes  in  several 
allied  genera,  found  in  various  parts  of  the  world.  Hence, 
in  accordance  with  the  descent-theory,  we  may  infer  that 
these  nine  species,  and  probably  all  the  others  of  the  genus, 
are  descended  from  an  ancestral  form  which  was  colored 
in  nearly  the  same  manner.  In  the  tenth  species  the  fe- 
male still  retains  the  same  general  coloring,  but  the  male 
resembles  her,  so  that  he  is  colored  in  a  much  less  gaudy 
and  contrasted  manner  than  the  males  of  the  previous 
species.  In  the  eleventh  and  twelfth  species,  the  females 
depart  from  the  type  of  coloring  which  is  usual  with 
their  sex  in  this  genus,  for  they  are  gayly  decorated  in 

*  See  also  Mr.  Bates's  paper  in  '  Proc.  Ent.  Soc.  of  Philadelphia,' 
1865,  p.  206.  Also  Mr.  Wallace  on  the  same  subject,  in  regard  to  Dia- 
dema,  in  'Transact.  Entomolog.  Soc.  of  London,'  1869,  p.  278. 


Chap.  XL]  BUTTERFLIES  AND  MOTHS.  377 

nearly  the  same  manner  as  the  males,  but  in  a  somewhat 
less  degree.  Hence  in  these  two  species  the  bright  colors 
of  the  males  seem  to  have  been  transferred  to  the  females ; 
while  the  male  of  the  tenth  species  has  either  retained  or 
recovered  the  plain  colors  of  tlie  female  as  well  as  of  the 
parent-form  of  the  genns ;  the  two  sexes  being  thus  ren- 
dered in  both  cases,  though  in  an  opposite  manner,  nearly 
alike.  In  the  allied  genus  Eubagis,  both  sexes  of  some  of 
the  species  are  plain-colored  and  nearly  alike ;  while  with 
the  greater  number  the  males  are  decorated  with  beauti- 
ful  metallic  tints,  in  a  diversified  manner,  and  differ  much 
from  their  females.  The  females  throughout  the  genus  re- 
tain the  same  general  style  of  coloring,  so  that  they  com- 
monly resemble  each  other  much  more  closely  than  they 
resemble  their  own  proper  males. 

In  the  genus  Papilio,  all  the  species  of  the  ^neas 
group  are  remarkable  for  their  conspicuous  and  strongly- 
contrasted  colors,  and  they  illustrate  the  frequent  ten- 
dency to  gradation  in  the  amount  of  difference  between 
the  sexes.  In  a  few  species,  for  instance,  in  P.  ascanius, 
the  males  and  females  are  alike ;  in  others  the  males  are 
a  little  or  very  much  more  superbly  colored  than  the  fe- 
males. The  genus  Junonia,  allied  to  our  Vanessoo,  offers  a 
nearly  parallel  case,  for  although  the  sexes  of  most  of  the 
species  resemble  each  other  and  are  destitute  of  rich  col- 
ors, yet  in  certain  species,  as  in  Jl  oeno7ie,  the  male  is 
rather  more  brightly  colored  than  the  female,  and  in  a  few 
(for  instance,  J[  andreinia^d)  the  male  is  so  different  from 
the  female  that  he  might  be  mistaken  for  an  entirely  dis- 
tmct  species. 

Another  striking  case  was  pointed  out  to  me  in  the 
British  Museum  by  Mr.  A.  Butler,  namely,  one  of  the 
Tropical  American  Thecla?,  in  which  both  sexes  are  nearly 
alike  and  wonderfully  splendid;  in  another,  the  male  is 
colored  in  a  similai-ly  gorgeous  manner,  while  the  whole 
17 


378  SEXUAL  SELECTION.  [Paut  IL 

upper  surface  of  the  female  is  of  a  dull  uniform  brown. 
Our  common  little  English  blue  butterflies,  of  the  genus 
Lyca3na,  illustrate  the  various  differences  in  color  between 
the  sexes,  almost  as  well,  though  not  in  so  striking  a  man- 
ner, as  the  above  exotic  genera.  In  Lyccena  agestis  both 
sexes  have  wings  of  a  brown  color,  bordered  with  small 
ocellated  orange  spots,  and  are  consequently  alike.  In  L. 
oigon  the  wings  of  the  male  are  of  a  fine  blue,  bordered 
with  black ;  while  the  Avings  of  the  female  are  brown,  with 
a  similar  border,  and  closely  resemble  those  of  L.  agestis. 
Lastly,  in  L.  arioji  both  sexes  are  of  a  blue  color  and 
nearly  alike,  though  in  the  female  the  edges  of  the  wings 
are  rather  duskier,  with  the  black  spots  j^lainer ;  and  in  a 
bright-blue  Indian  species  both  sexes  are  still  more  closely 
alike. 

I  have  given  the  foregoing  cases  in  some  detail,  in 
order  to  show,  in  the  first  place,  that,  when  the  sexes  of 
butterflies  differ,  the  male  as  a  general  rule  is  the  most 
beautiful,  and  departs  most  from  the  usual  type  of  color- 
ing of  the  group  to  which  the  species  belongs.  Hence  in 
most  groups  the  females  of  the  several  species  resemble 
each  other  much  more  closely  than  do  the  males.  In 
some  exceptional  cases,  liowever,  to  which  I  shall  here- 
after allude,  the  females  are  colored  more  splendidly  than 
the  males.  In  the  second  place,  these  cases  have  been 
given  to  bring  clearly  before  the  mind  that,  within  the 
same  genus,  the  two  sexes  frequently  j^resent  every  gra- 
dation from  no  difference  in  color  to  so  great  a  difference 
that  it  was  long  before  the  two  wei-e  placed  by  entomolo- 
gists in  the  same  genus.  In  the  third  place,  we  have  seen 
that,  when  the  sexes  nearly  resemble  each  other,  this  ap- 
parently may  be  due  either  to  the  male  having  transferred 
his  colors  to  the  female,  or  to  the  male  having  retained, 
or  perhaps  i-ecovercd,  the  primordial  colors  of  the  genus 
to  which  the  species  belongs.     It  also  deserves  notice  that 


CiiAP.  XI.]  BUTTERFLIES   AND   MOTHS.  379 

in  those  groups  in  which  the  sexes  present  any  difierence 
of  color,  the  females  usually  resemble  the  males  to  a  cer- 
tain extent,  so  that,  when  the  males  are  beautiful  to  an  ex- 
traordinary degree,  the  females  almost  invariably  exhibit 
some  degree  of  beauty.  From  the  numerous  cases  of  gra- 
dation in  the  amount  of  diiference  between  the  sexes,  and 
from  the  prevalence  of  the  same  general  type  of  coloration 
throughout  the  whole  of  the  same  group,  Ave  may  con- 
clude that  the  causes,  whatever  they  may  be,  which  have 
determined  the  brilliant  coloring  of  the  males  alone  of 
some  species,  and  of  both  sexes  in  a  more  or  less  equal 
degree  of  other  species,  have  genei'ally  been  the  same. 

As  so  many  gorgeous  butterflies  inhabit  the  tropics,  it 
has  often  been  supposed  that  they  owe  their  colors  to  the 
great  heat  and  moisture  of  these  zones ;  but  Mr.  Bates  * 
has  shown,  by  the  comparison  of  various  closely-allied 
groups  of  insects  from  the  temjoerate  and  tropical  regions, 
that  this  view  cannot  be  maintained ;  and  the  evidence 
becomes  conclusive  when  brilliantly-colored  males  and 
plain-colored  females  of  the  same  species  inhabit  the  same 
district,  feed  on  the  same  food,  and  follow  exactly  the 
same  habits  of  life.  Even  when  the  sexes  resemble  each 
other,  we  can  hardly  believe  that  their  brilliant  and  beau- 
tifully-arranged colors  are  the  purposeless  result  of  the 
nature  of  the  tissues,  and  the  action  of  the  surrounding- 
conditions. 

With  animals  of  all  kinds,  v/henever  color  has  been 
modified  for  some  special  purpose,  this  has  been,  as  far  as 
we  can  judge,  either  for  protection  or  as  an  attraction  be- 
tween the  sexes.  With  many  species  of  butterflies  the 
upper  surfaces  of  the  wings  ai"e  obscurely  colored,  and 
this  in  all  probability  leads  to  their  escaping  observation 
and  danger.  But  butterflies  when  at  rest  would  be  j)ar- 
ticularly  liable  to  be  attacked  by  their  enemies ;  and  al- 
*  '  The  Naturalist  on  the  Amazons,'  vol.  i.  1863,  p.  19. 


380  SEXUAL  SELECTIOX.  [Part  II. 

most  all  the  kinds  when  resting  raise  their  wings  verti- 
cally over  their  backs,  so  that  the  lower  sides  alone  are 
exposed  to  view.  Hence  it  is  this  side  which  in  many- 
cases  is  obviously  colored  so  as  to  imitate  the  surfaces  on 
which  these  insects  commonly  rest.  Dr.  Rossler,  I  be- 
lieve, first  noticed  the  similarity  of  the  closed  wings  of 
certain  VanesssB  and  other  butterflies  to  the  bark  of  trees. 
Many  analogous  and  striking  facts  could  be  given.  The 
most  interesting  one  is  that  recorded  by  Mr.  Wallace  " 
of  a  common  Indian  and  Sumatran  buttei-fly  (Kallima), 
which  disappears  like  magic  when  it  settles  in  a  bush ; 
for  it  hides  its  head  and  antennre  between  its  closed 
wings,  and  these,  in  form,  color,  and  veining,  cannot  be 
distinguished  from  a  withered  leaf  together  with  the  foot- 
stalk. In  some  other  cases  the  lower  surfaces  of  the 
wings  are  brilliantly  colored,  and  yet  are  protective ;  thus 
in  Thecla  rubi  the  wings  vrhen  closed  are  of  an  emerald 
green  and  resemble  the  young  leaves  of  the  bramble,  on 
which  this  butterfly  in  the  spring  may  often  be  seen 
seated. 

Although  the  obscure  tints  of  the  upper  or  under  sur- 
face of  many  butterflies  no  doubt  serve  to  conceal  them, 
yet  we  cannot  possibly  extend  this  vievv^  to  the  brilliant 
and  conspicuous  colors  of  many  kinds,  such  as  our  admiral 
and  peacock  Vanessoe,  our  white  cabbage-butterflies  (Pie- 
ris),  or  the  great  swallow-tail  Papilio  which  haunts  the 
open  fens — for  these  butterflies  are  thus  rendered  visible 
to  every  living  creature.  With  these  species  both  sexes 
are  alike;  but  in  the  common  brimstone  butterfly  (^Go- 
neptery?::,  rhamni)  the  male  is  of  an  intense  yellovv',  while 
the  female  is  much  paler ;  and  in  the  orange-tip  [Ant/io- 
charis    cardamines)   the   males    alone  have  the    bright 

''  See  the  interesting  article  in  the  '  Westminster  Review,'  July,  ISGT, 
p.  10.  A  woodcut  of  the  Kallima  is  given  by  Mr.  Wallace  in  '  Tlard- 
v.-icke's  Seienco  Gossip,'  Sept.,  ISC'/,  p.  10(5. 


Chap.  XI.]  BUTTERFLIES  AND   MOTHS.  381 

orange  tips  to  their  wings.  In  these  cases  the  males  and 
females  are  equally  conspicuous,  and  it  is  not  credible 
that  their  difference  in  color  stands  in  any  relation  to  or- 
dinary protection.  Nevertheless,  it  is  possible  that  the 
conspicuous  colors  of  many  species  may  be  in  an  indirect 
manner  beneficial,  as  will  hereafter  be  explained,  by  lead- 
ing their  enemies  at  once  to  recognize  them  as  unpala- 
table. Even  in  this  case  it  does  not  certainly  follow  that 
their  bright  colors  and  beautiful  patterns  were  acquired 
for  this  special  purpose.  In  some  other  remarkable  cases, 
beauty  has  been  gained  for  the  sake  of  protection,  through 
the  imitation  of  other  beautiful  species,  which  inhabit  the 
same  district  and  enjoy  an  immunity  from  attack  by  be- 
ing in  some  way  offensive  to  their  enemies. 

The  female  of  our  orange-tip  butterfly,  above  referred 
to,  and  of  an  American  species  {Anth.  genutia)  probably 
show  us,  as  Mr.  Walsh  has  remarked  to  me,  the  primordial 
colors  of  the  parent-species  of  the  genus ;  for  both  sexes 
of  four  or  five  widely-distributed  species  are  coloi'ed  in 
nearly  the  same  manner.  We  may  infer  here,  as  in  several 
previous  cases,  that  it  is  the  males  of  Anth.  cardmnines 
and  genutia  which  have  departed  from  the  usual  type  of 
coloring  of  their  genus.  In  the  Anth.  sara  from  California, 
the  orange-tips  have  become  partially  developed  in  the  fe- 
male ;  for  her  wings  are  tipped  with  reddish  orange,  but 
paler  than  in  the  male,  and  slightly  different  in  some  other 
respects.  In  an  allied  Indian  form,  the  Iphias  glaucippe^ 
the  orange-tips  are  fully  developed  in  both  sexes.  In  this 
Iphias  the  under  surface  of  the  wings  marvellously  resem- 
bles, as  pointed  out  to  me  by  Mr.  A.  Butler,  a  pale-col- 
ored leaf ;  and,  in  our  English  orange-tip,  the  under  surface 
resembles  the  flower-head  of  the  wild-parsley,  on  which  it 
may  be  seen  going  to  rest  at  night."     The  same  reasoning 

«  See  the  interesting  observations  by  Mr.  T.  W.  "Wood,  '  The  Stu- 
dent,' Sept.  1868,  p.  81. 


382  SEXUAL  SELECTION.  [Part  IL 

power  which  comjicls  us  to  believe  that  the  lower  surfaces 
have  here  been  colored  for  the  sake  of  protection,  leads  us 
to  deny  that  the  wings  have  been  tipped,  especially  when 
this  character  is  confined  to  the  males,  with  bright  orange 
for  the  same  jnirpose. 

Turning  now  to  Moths :  most  of  these  rest  motionless 
with  their  wings  de2')ressed  dm-ing  the  whole  or  greater 
part  of  the  day ;  and  the  upper  surfaces  of  their  wings 
are  often  shaded  and  colored  in  an  admii-able  manner,  as 
Mr.  Wallace  has  remarked,  for  escaping  detection.  With 
most  of  the  Bombycidce  and  Noctuida;,'  when  at  rest,  the 
front-wings  overlap  and  conceal  the  hind- wings ;  so  that 
the  latter  might  be  brightly  colored  without  much  risk  ; 
and  they  are  thus  colored  in  many  species  of  both  families. 
During  the  act  of  flight,  moths  would  often  be  able  to  es- 
cape from  their  enemies ;  nevertheless,  as  the  hind-"vvings 
are  then  fully  exposed  to  view,  their  bright  colors  must 
generally  have  been  acqiiired  at  the  cost  of  some  little 
risk.  But  the  following  fact  shows  us  how  cautious  we 
ought  to  be  in  drawing  conclusions  on  this  head.  The 
common  yellow  under-wings  (Triphaena)  often  fly  about 
during  the  day  or  early  evening,  and  are  then  conspicuous 
from  the  color  of  their  hind-wings.  It  would  naturally 
be  thought  that  this  would  be  a  source  of  danger ;  but 
Mr.  J.  Jenner  Weir  believes  that  it  actually  serves  them 
as  a  means  of  escape,  for  birds  strike  at  these  brightly- 
colored  and  fragile  surfaces,  instead  of  at  the  body.  For 
instance,  Mr.  Weir  turned  into  his  aviary  a  vigorous  spe- 
cimen of  Triphaena  2n'0)it(ba,  which  was  instantly  pur- 
sued by  a  robin ;  but,  the  bird's  attention  being  caught 
by  the  colored  wings,  the  moth  was  not  captured  until 
after  about  fifty  attcni})ts,  and  small  portions  of  the  wings 
were  repeatedly  broken  off.     lie  tried  the  same  experi- 

'  Mr.  Wallace  in  '  Ilardwickc's  Science  Gossip,'  Sept.  ISGT,  p.  193. 


Chap.  XI.]  BUTTERFLIES  AND   MOTES.  383 

meut,  in  the  open  air,  with  a  T.  f.mhria  and  swallow ; 
but  the  hirge  size  of  this  moth  probably  interfered  with 
its  capture/  We  are  thus  reminded  of  a  statement  made 
by  Mr.  Wallace,'  namely,  that,  in  the  Brazilian  forests  and 
Malayan  islands,  many  common  and  highly-decorated  but- 
terflies are  weak  flyers,  though  furnished  with  a  broad  ex- 
panse of  wings ;  and  they  "  are  often  captured  with  pierced 
and  broken  wings,  as  if  they  had  been  seized  by  birds, 
from  which  they  had  escaped :  if  the  wings  had  been  much 
smaller  in  proportion  to  the  body,  it  seems  probable  that 
the  insect  would  more  frequently  have  been  struck  or 
pierced  in  a  vital  part,  and  thus  the  increased  expanse  of 
the  T^dngs  may  have  been  indirectly  beneficial." 

Displcoj. — The  bright  colors  of  butterflies  and  of  some 
moths  are  specially  arranged  for  display,  whether  or  not 
they  serve  in  addition  as  a  protection.  Bright  colors 
would  not  be  visible  during  the  night :  and  there  can  be 
no  doubt  that  moths,  taken  as  a  body,  are  much  less  gayly 
decorated  than  butterflies,  all  of  which  are  diurnal  in  their 
habits.  But  the  moths  in  certain  families,  such  as  the 
ZygsenidiB,  various  Sphingidre,  UraniidaB,  some  Arctiidce 
and  Saturniidse,  fly  about  during  the  day  or  early  evening, 
and  many  of  these  are  exti*emely  beautiful,  being  far  more 
brightly  colored  than  the  strictly  nocturnal  khids.  A  few 
exceptional  cases,  however,  of  brightly-colored  nocturnal 
species  have  been  recorded." 

There  is  evidence  of  another  kind  in  regard  to  display. 

«  See  also,  on  this  subject,  Mr.  Weir's  paper  hi  '  Transact.  Ent.  Soc' 
1869,  p.  23. 

9  '  Westminster  Review,'  July,  1867,  p.  16. 

'"  For  instance,  Lithosia ;  but  Prof.  Westwood  ('  Modern  Class,  of 
Insects,'  vol.  ii.  p.  300)  seems  surprised  at  this  case.  On  the  relative 
colors  of  diurnal  and  nocturnal  Lepidoptera,  see  ibid.  pp.  333,  392  ;  also 
Ha.-n.=,  '  Treatise  on  thn  Insect;;  of  Xew  England,'  18-12,  p.  315. 


384  SEXUAL   SELECTION.  [Part  IL 

ButterJBlies,  as  before  remarked,  elevate  their  wings  when 
at  rest,  and  while  basking  in  the  sunshine  often  alternately 
raise  and  depress  them,  thus  exposing  to  full  view  both 
surfaces ;  and,  although  the  lower  surface  is  often  colored 
in  an  obscure  manner  as  a  protection,  yet  in  many  species 
it  is  as  highly  colored  as  the  upper  surface,  and  sometimes 
in  a  veiy  different  manner.  In  some  tropical  species  the 
lower  surface  is  even  more  brilliantly  colored  than  the 
upper."  In  one  English  fritillary,  the  Argymiis  aglaia, 
the  lower  surface  alone  is  ornamented  with  shining  silver 
disks.  Nevertheless,  as  a  general  rule,  the  upper  surface, 
which  is  i^robably  the  most  fully  exposed,  is  colored  more 
brightly  and  in  a  more  diversified  manner  than  the  lower. 
Hence  the  lower  surface  generally  affords  to  entomologists 
the  most  useful  character  for  detecting  the  affinities  of 
the  various  species. 

NoAV  if  we  turn  to  the  enormous  group  of  moths,  which 
do  not  habitually  expose  to  full  view  the  under  surfoce  of 
their  wings,  this  side  is  very  rarely,  as  I  hear  from  Mr. 
Stainton,  colored  more  brightly  than  the  upper  side,  or 
even  with  equal  bi'ightness.  Some  exceptions  to  the  rule, 
either  real  or  apparent,  must  be  noticed,  as  that  of  Hypo- 
pira,  specified  by  Mr.  Wormald."  Mr.  R.  Trimen  informs 
me  that,  in  Guenee's  great  work,  three  moths  are  figured, 
in  which  the  under  surface  is  much  the  most  brilliant. 
For  instance,  in  the  Australian  Gasti-ophora  the  upper 
surface  of  the  fore-wing  is  pale  grayish-ochreous,  while 
the  lower  surface  is  magnificently  ornamented  by  an  ocel- 
lus of  cobalt-blue,  placed  in  the  midst  of  a  black  mark, 
surrounded  by  orange-yellow,  and  this  by  bluish-white. 

"  Such  differences  between  the  upper  and  lower  surfaces  of  the  wings 
of  several  species  of  Papilio  may  be  seen  ui  the  beautiful  plates  to  Mr. 
Wallace's  Memoir  on  the  PapilionidiB  of  the  Malayan  Region,  in  '  Trans- 
act. Linn.  Soc.'  vol.  xxv.  part  i.  18G5. 

'■^  '  Proc.  Ent.  Soc'  March  2,  1808. 


Chap.  XL]  BUTTERFLIES  AND   MOTHS.  385 

But  the  habits  of  these  three  moths  are  unknoAvn ;  so  that 
no  explanation  can  be  given  of  theii*  unusual  style  of  col- 
oring. Mr.  Trimeu  also  informs  me  that  the  lower  sur- 
face of  the  wings  in  certain  other  Geometrae  "  and  quadri- 
fid  Noctuse  is  either  more  variegated  or  more  brightly- 
colored  than  the  xipper  surface  ;  but  some  of  these  species 
have  the  habit  of  "  holding  their  wings  quite  erect  over 
their  backs,  retaining  them  in  this  position  for  a  consider- 
able time,"  and  thus  exposing  to  view  the  under  surface. 
Other  species,  when  settled  on  the  ground  or  herbage, 
have  the  habit  of  now  and  then  suddenly  and  slightly 
lifting  up  their  wings.  Hence,  the  lower  surface  of  the 
Avings  being  more  brightly  colored  than  the  upper  surface, 
in  certain  moths,  is  not  so  anomalous  a  circumstance  as  it 
at  first  appears.  The  Saturniidse  include  some  of  the 
most  beautiful  of  all  moths,  their  wings  being  decorated, 
as  in  our  British  Emperor  moth,  with  fine  ocelli ;  and  Mr. 
T.  W.  Yfood  "  observes  that  they  resemble  butterflies  in 
some  of  their  movements  ;  "  for  instance,  in  the  gentle 
waving  up  and  down  of  the  wings,  as  if  for  display,  which 
is  more  characteristic  of  diurnal  than  of  nocturnal  Lepi- 
doptera." 

It  is  a  singular  fact  that  no  British  moths,  nor,  as  far 
as  I  can  discover,  hardly  any  foreign  species,  which  are 
brilliantly  colored,  differ  much  in  color  according  to  sex  ; 
though  this  is  the  case  with  many  brilliant  butterflies. 
The  male,  however,  of  one  American  moth,  the  Saturnia 
lo,  is  described  as  having  its  fore-wings  deep  yellow, 
curiously  marked  with  purplish-red  spots ;  while  the  wings 
of  the  female  are  purple-brown,  marked  with  gray  lines." 
The  British  moths  which  differ  sexually  in  color  are  all 

'3  See  also  an  account  of  the  South  American  genus  Erateina  (one  of 
the  Geometrae)  in  '  Transact.  Ent.  Soc'  new  series,  vol.  v,  pis.  xv.,  xvi. 
1*  '  Proc.  Ent.  Soc.  of  London,'  July  6,  1868,  p.  xxvii. 
15  Harri:-,  '  Treatise,'  etc.,  edited  by  Flint,  18G2,  p.  395. 


3SG  SEXUAL  SELECTION.  [Part  IL 

brown,  or  various  tints  of  dull  yelloAV,  or  nearly  -white. 
In  several  species  tlie  males  are  much  darker  than  the 
females,"  and  these  belong  to  groups  ■which  generally  fly 
about  during  the  afternoon.  On  the  other  hand,  in  many 
genera,  as  Mr.  Stainton  inforais  me,  the  males  have  the 
hind-wings  whiter  than  those  of  the  female — of  which  fact 
Agrotis  exclamationis  offers  a  good  instance.  The  males 
are  thus  rendered  more  conspicuous  than  the  females, 
while  flying  about  in  the  dusk.  In  the  Ghost  Moth  {He- 
2)ialus  humiili)  the  difference  is  more  strongly  marked ; 
the  males  being  white,  and  the  females  yellow,  with 
darker  markings.  It  is  difficult  to  conjecture  what  the 
meaning  can  be  of  these  differences  between  the  sexes  in 
the  shades  of  darkness  or  lightness ;  but  we  can  hardly 
suppose  that  they  are  the  result  of  mere  variability  with 
sexually-limited  inheritance,  independently  of  any  benefit 
thus  derived. 

From  the  foregoing  statements  it  is  impossible  to  ad- 
mit that  the  brilliant  colors  of  butterflies  and  of  some  few 
moths  have  commonly  been  acquired  for  the  sake  of  pro- 
tection. We  have  seen  that  their  colors  and  elegant  pat- 
terns are  arranged  and  exhibited  as  if  for  display.  Hence 
I  am  led  to  suppose  that  the  females  generally  prefer,  or 

'*  For  instanoe,  I  observe  in  my  son's  cabinet  that  the  males  are 
darker  than  tlie  females  in  the  Lasiocampa  guefcus,  Odoncsiis potaioria, 
Jhjpocjymna  dispar,  Dasyclilra  picdibiinda,  and  Cycnia  7nendica.  In  this 
latter  species  the  difference  in  color  between  the  two  sexes  is  strongly 
marked ;  and  Mr.  Wallace  infonns  me  that  we  here  have,  as  he  believe?, 
an  instance  of  protective  mimicry  confined  to  one  sex,  as  will  hereafter 
be  more  fully  explained.  The  white  female  of  the  Cycnia  resembles  the 
very  common  Spilosoma  mcnthrasti,  both  sexes  of  which  are  white ;  and 
J[r.  Stainton  observed  that  this  latter  moth  was  rejected  with  utter  dis- 
trust by  a  whole  brood  of  young  turkeys,  which  were  fond  of  eating  other 
inoths  ;  so  that,  if  the  Cycnia  was  commonly  mistaken  by  British  birds 
for  the  Spilosoma,  it  would  escape  being  devoured,  and  its  white  decep- 
tive color  would  thus  be  highlv  beneficial. 


Chap.  XI.]  BUTTERFLIES  AND  MOTHS.  387 

are  most  excited  by  the  more  brilliant  males  ;  for  on  any 
other  supposition  the  males  would  be  ornamented,  as  far 
as  we  can  see,  for  no  purpose.  "We  know  that  ants  and 
certain  lamellicorn  beetles  are  capable  of  feeling  an  at- 
tachment for  each  other,  and  that  ants  recognize  their  fel- 
lows after  an  interval  of  several  months.  Hence  there  is 
no  abstract  improbability  in  the  Lepidoptera,  which  prob- 
ably stand  nearly  or  quite  as  high  in  the  scale  as  these 
insects,  having  sufficient  mental  capacity  to  admire  bright 
colors.  They  certainly  discover  flowers  by  color,  and,  as 
I  have  elsewhere  shown,  the  plants  which  are  fertilized 
exclusively  by  the  wind  never  have  a  conspicuously-col- 
ored corolla.  The  Humming-bird  Sphinx  may  often  be 
seen  to  swoop  down  from  a  distance  on  a  bunch  of  flowers 
in  the  midst  of  green  foliage ;  and  I  have  been  assured 
by  a  friend  that  these  moths  repeatedly  visited  flowers 
painted  on  the  walls  of  a  room  in  the  south  of  France. 
The  common  white  butterfly,  as  I  hear  from  Mr.  Double- 
day,  often  flies  down  to  a  bit  of  paper  on  the  ground,  no 
doubt  mistaking  it  for  one  of  its  own  species.  Mr.  Col- 
lingwood,"  in  speaking  of  the  difficulty  of  collecting  cer- 
tain butterflies  in  the  Malay  Archipelago,  states  that  "  a 
dead  'specimen  pinned  upon  a  conspicuous  twig  will  often 
arrest  an  insect  of  the  same  species  in  its  headlong  flight 
and  bring  it  down  within  easy  reach  of  the  net,  especially 
if  it  be  of  the  oj^posite  sex." 

The  courtship  of  butterflies  is  a  prolonged  afiliir. 
The  males  sometimes  fight  together  in  rivalry ;  and  many 
may  be  seen  pursuing  or  crowding  round  the  same  female. 
If,  then,  the  females  do  not  prefer  one  male  to  another, 
the  pairing  must  be  left  to  mere  chance,  and  this  does 
not  appear  to  me  a  probable  event.  If,  on  the  other  hand, 
the  females  habitually,  or  even  occasionally,  prefer  the 
more  beautiful  males,  the  colors  of  the  latter  will  have 
1'  '  Rambles  of  a  Naturalir-t  in  the  Chinese  Seas,'  1868,  p.  182. 


3S8  SEXUAL  SELECTION.  [Part  IL 

been  i*endered  brighter  by  degrees,  and  will  have  been 
transmitted  to  both  sexes  or  to  one  sex,  according  to 
which  law  of  inheritance  prevailed.  The  process  of  sexual 
selection  Avill  have  been  much  facilitated,  if  the  conclu- 
sions arrived  at  from  various  kinds  of  evidence  in  the  sup- 
plement to  the  ninth  chapter  can  be  trusted ;  namely,  that 
the  males  of  many  Lepidoptcra,  at  least  in  the  imago 
state,  greatly  exceed  in  number  the  females. 

Some  facts,  however,  are  opposed  to  the  belief  that 
female  biitterflies  prefer  the  more  beautiful  males ;  thus, 
as  I  have  been  assured  by  several  observers,  fresh  females 
may  frequently  be  seen  paired  with  battered,  faded,  or 
dingy  males ;  but  this  is  a  circumstance  which  could  hard- 
ly fail  often  to  follow  from  the  males  emerging  from  theii- 
cocoons  earlier  than  the  females.  With  moths  of  the 
family  of  the  Bombycida?,  the  sexes  pair  immediately  after 
assuming  the  imago  state ;  for  they  cannot  feed,  owing  to 
the  rudimentary  condition  of  their  mouths.  The  females, 
as  several  entomologists  have  remarked  to  me,  lie  in  an  ' 
almost  torpid  state,  and  appear  not  to  evince  the  least 
choice  in  regard  to  their  partners.  This  is  the  case  with 
the  common  silk-moth  (7>.  mori),  as  I  have  been  told  by 
some  Continental  and  English  breeders.  Dr.  "Wallace, 
who  has  had  such  immense  experience  in  breeding  Bom- 
byx  cynthia,  is  convinced  that  the  females  evince  no  choice 
or  preference.  He  has  kept  above  300  of  these  moths  liv- 
ing together,  and  has  often  found  the  most  vigorous  fe- 
males mated  with  stunted  males.  The  reverse  apparently 
seldom  occurs ;  for,  as  he  believes,  the  more  vigorous 
males  pass  over  the  weakly  females,  being  attracted  by 
those  endowed  with  most  vitality.  Although  we  have 
Ijcen  indii-ectly  induced  to  believe  that  the  females  of 
many  species  prefer  the  more  beautiful  males,  I  have  no 
reason  to  suspect,  either  with  moths  or  butterflies,  that 
the  males  are  attracted  by  the  beauty  of  the  females.     If 


CirAr.  XL]  BUTTERFLIES  AND   MOTHS.  389 

the  more  beautiful  females  had  been  continually  preferred, 
it  is  almost  certain,  from  the  colors  of  butterflies  being  so 
frequently  transmitted  to  one  sex  alone,  that  the  females 
would  often  have  been  rendered  more  beautiful  than  their 
male  jjartners.  But  this  does  not  occur  except  in  a  few 
instances ;  and  these  can  be  explained,  as  we  shall  pres- 
ently see,  on  the  principle  of  mimicry  and  protection. 

As  sexual  selection  primarily*  depends  on  variability,  a 
few  words  must  be  added  on  this  subject.  In  respect  to 
color  there  is  no  difficulty,  as  any  number  of  highly-varia- 
ble Lepidoptera  could  be  named.  One  good  instance  will 
suffice :  Mr.  Bates  showed  me  a  whole  series  of  specimens 
of  Papilio  sesostris  and  childrence  ;  in  the  latter  the  males 
varied  much  in  the  extent  of  the  beautifully-enamelled 
green  patch  on  the  fore-wings,  and  in  the  size  of  the  white 
mark,  as  well  as  of  the  splendid  crimson  stripe  on  the 
hind-wings ;  so  that  there  was  a  great  conti-ast  between 
the  most  and  least  gaudy  males.  The  male  of  Papilio 
sesostris,  though  a  beautiful  insect,  is  much  less  so  than 
2\  childrencB.  It  likewise  varies  a  little  in  the  size  of  the 
green  patch  on  the  fore-wings,  and  in  the  occasional  ap- 
pearance of  a  small  crimson  sti'ipe  on  the  hind-wings,  bor- 
rowed, as  it  would  seem,  from  its  owm  female ;  for  the  fe- 
males of  this  and  of  many  other  species  in  the  -iEneas 
group  possess  this  crimson  stripe.  Hence,  between  the 
brightest  specimens  of  P.  sesostris  and  the  least  bright  of 
P.  childreiice,  there  w^as  but  a  small  interval ;  and  it  was 
evident  that,  as  far  as  mere  variability  is  concerned,  there 
would  be  no  difficulty  in  permanently  increasing,  by  means 
of  selection,  the  beauty  of  either  species.  The  variability 
is  here  almost  confined  to  the  male  sex  ;  but  Mr.  Wallace 
and  Mr,   Bates   have  shown  '^  that  the  females  of  some 

18  Wallace  on  the  PapilionidfC  of  the  Malayan  Region,  in  '  Transact. 
Linn.  Soc'  vol.  xxv.  1865,  pp.  8,  36.     A  striking  case  of  a  rare  variety, 


30O  SEXUAL  SELECTION.  [Part  IL 

otlicr  species  are  extremely  variable,  the  males  being 
nearly  constant.  As  I  have  before  mentioned  the  Ghost 
Moth  {Hepialus  huniuU)  as  one  of  the  best  instances  in 
Britain  of  a  difference  in  color  between  the  sexes  of 
moths,  it  may  be  worth  adding "  that,  in  the  Shetland 
Islands,  males  are  frequently  found  which  closely  resem- 
ble the  females.  In  a  future  chapter  I  shall  have  occasion 
to  show  that  the  beautiful  eye-like  spots  or  ocelli,  so  com- 
mon on  tlie  wings  of  many  Lepidoptera,  are  eminently 
variable. 

On  the  whole,  althougn  many  serious  objections  may 
be  urged,  it  seems  probable  that  most  of  the  species  of 
Le2)idoptera  which  are  brilliantly  colored,  owe  their  col- 
ors to  sexual  selection,  excepting  in  certain  cases,  pres- 
ently to  be  mentioned,  in  which  conspicuous  colors  are 
beneficial  as  a  protection.  From  the  ardor  of  the  male 
throughout  the  animal  kingdom,  he  is  generally  Avilling  to 
accept  any  female ;  and  it  is  the  female  which  usually  ex- 
erts a  choice.  Hence,  if  sexual  selection  has  here  acted, 
the  male,  when  the  sexes  differ,  ought  to  be  the  most 
brilliantly  colored  ;  and  this  undoubtedly  is  the  ordinary 
rule.  When  the  sexes  are  brilliantly  colored  and  resem- 
ble each  other,  the  characters  acquired  by  the  males  ap- 
pear to  have  been  transmitted  to  both  sexes.  But  will 
this  explanation  of  the  similarity  and  dissimilarity  in 
color  between  the  sexes  suffice  ? 

The  males  and  females  of  the  same  species  of  butterfly 
are  knoAvn  "  in  several  cases  to  inhabit  different  stations, 

strictly  intermediate  between  two  other  well-marked  female  varieties,  is 
given  by  Mr.  "Wallace.     See  also  Mr.  Bates,  in  '  I'roc.  Entomolog.  Soc 
Nov.  19,  18C(),  p.  xl. 

"  Mr.  R.  MacLaclilan,  '  Transact.  Ent.  Soc'  vol.  ii.  part  6th,  3d  series, 
186C,  p.  459. 

^^  II.  W.  Bates,  'The  Naturalist  on  the  Amazons,'  vol.  ii.  1863,  p. 
228.     A.  R.  Wallace,  in  '  Transact.  Linn.  Soc'  vol.  xxv.  1865,  p.  10. 


Chap.  XL]  BUTTERFLIES  AND  MOTHS.  391 

the  former  commonly  basking  in  the  sunshine,  the  latter 
haunting  gloomy  forests.  It  is  therefore  possible  that 
different  conditions  of  life  may  have  acted  directly  on  the 
two  sexes ;  but  this  is  not  probable,^*  as  in  the  adult  state 
they  are  exposed  during  a  very  short  period  to  different 
conditions  ;  and  the  larvce  of  both  are  exposed  to  the  same 
conditions.  Mr.  Wallace  believes  that  the  less  brilliant 
colors  of  the  female  have  been  specially  gained  in  all  or 
almost  all  cases  for  the  sake  of  protection.  On  the  con- 
trary, it  seems  to  me  more  probable  that  the  males  alone, 
in  the  large  majority  of  cases,  have  acquired  their  bright 
colors  through  sexual  selection,  the  females  having  been 
but  little  modified.  Consequently  tlie  females  of  distinct 
but  allied  species  ought  to  resemble  each  other  much 
more  closely  than  do  the  males  of  the  same  species  ;  and 
this  is  the  general  rule.  The  females  thus  apj)roximately 
show  us  the  primordial  coloring  of  the  parent-species  of 
the  group  to  which  they  belong.  They  have,  however, 
almost  always  been  modified  to  a  certain  extent  by  some 
of  the  successive  stejDS  of  variation,  through  the  accumula- 
tion of  which  the  males  were  rendered  beautiful,  having 
been  transferred  to  them.  The  males  and  females  of  allied 
though  distinct  species  will  also  generally  have  been  ex- 
posed during  their  prolonged  larval  state  to  different  con- 
ditions, and  may  have  been  thus  indirectly  affected; 
though  with  the  males  any  slight  change  of  color  thus 
caused  will  often  have  been  completely  masked  by  the 
brilliant  tints  gained  through  sexual  selection.  When  we 
treat  of  Birds,  I  shall  have  to  discuss  the  whole  question 
whether  the  differences  in  color  between  the  males  and 
females  have  been  in  part  specially  gained  by  the  latter 
as  a  protection ;  so  that  I  will  here  only  give  unavoidable 
details. 

^^  On  this  whole  subject,  see  '  The  Variation  of  Animals  and  Plants 
under  Domestication,'  vol.  ii.  1868,  chap,  xsiii. 


392  SEXUAL  SELECTION.  [Paht  II. 

Ill  all  cases  when  the  more  common  form  of  equal  in- 
heritance by  both  sexes  has  prevailed,  the  selection  of 
bright-colored  males  would  tend  to  make  the  females 
bright-colored ;  and  the  selection  of  dull-colored  females 
would  tend  to  make  the  males  dull.  If  both  processes 
were  carried  on  simultaneously,  they  would  tend  to  neu- 
tralize each  other.  As  far  as  I  can  see,  it  Avould  be  ex- 
tremely difficult  to  change  through  selection  the  one  form 
of  inheritance  into  the  other.  But,  by  the  selection  of  suc- 
cessive variations,  which  were  fi-om  the  first  sexually  lim- 
ited in  their  transmission,  there  would  not  be  the  slightest 
difficulty  in  giving  bright  colors-  to  the  males  alone,  and 
at  the  same  time,  or  subsequently,  dull  colors  to  the  fe- 
males alone.  In  this  latter  manner  female  butterflies  and 
moths  may,  as  I  fully  admit,  have  been  rendered  incon- 
spicuous for  the  sake  of  protection,  and  widely  different 
from  their  males. 

Mr.  Wallace  ^'  has  argued  with  much  force  in  favor  of 
his  view  that,  when  the  sexes  diffi?r,  the  female  has  been 
specially  modified  for  the  sake  of  pi'otection ;  and  that 
has  been  efiected  by  one  form  of  inheritance,  namely,  the 
transmission  of  characters  to  both  sexes,  having  been 
changed  through  the  agency  of  natural  selection  into  the 
other  form,  namely,  transmission  to  one  sex.  I  was  at 
first  strongly  inclined  to  accept  this  view;  but, the  more  I 
have  studied  the  various  classes  throughout  the  animal 
kingdom,  the  less  probable  it  has  appeared.  Mr.  Wallace 
urges  that  both  sexes  of  the  JIelieo7iidce,  Danaidce^Acro- 
eidce,  are  equally  brilliant  because  both  are  protected 
from  the  attacks  of  birds  and  other  enemies,  by  their  of- 
fensive odor ;  but  that  in  other  groups,  Avhich  do  not 
possess  this  immunity,  the  females  have  been  rendered 

=•- A.  R.  Wallace,  in  'The  Journal  of  Travel,'  vol.  i.  1868,  p.  88. 
'  ^Vcstmiuster  Review,'  July,  186Y,  p.  37.  Sec  also  Messrs.  Wallace  and 
ISatcs  in  Troc.  Ent.  Poc.'  Nov.  19,  ISCG,  p.  xxxix. 


Chap.  XL]  BUTTERFLIES  AND   MOTHS.  393 

inconspicuous,  from  having  more  need  of  protection  than 
the  males.     This  supposed  difference  in  the  "  need  of  pro- 
tection by  the  two  sexes  "  is  rather  deceptive,  and  requires 
some  discussion.     It  is  obvious  that  bi'ightly-colored  indi- 
viduals, whether  males  or  females,  would  equally  attract, 
and  obscurely-colored  individuals  equally  escape,  the  at- 
tention of  their  enemies.     But  we  are  concerned  with  the 
effects  of  the  destruction  or  preservation  of  certain  indi- 
viduals, of  either  sex,  on  the  character  of  the  race.     With 
insects,  after  the  male  has  fertilized  the  female,  and  after 
the  latter  has  laid  her  eggs,  the  greater  or  less  immunity 
from  danger  of  either  sex  could  not  possibly  have  any 
elFect  on  the  offspring.     Before  the  sexes  have  performed 
their  proper  functions,  if  they  existed  in  equal  numbers 
and  if  they  strictly  paired  (all  other  circumstances  being 
the   same),  the   preservation  of  the   males   and   females 
would  be  equally  impoi'tant  for  the  existence  of  the  spe- 
cies  and  for  the  character   of  the  offspring.     But  with 
most  animals,  as  is  known  to  be  the  case  with  the  do- 
mestic  silk-moth,   the   male   can    fertilize    two   or   three 
females  ;  so  that  the  destruction  of  the  males  would  not 
be  so  injurious  to  the  species  as  that  of  the  females.     On 
the  other  hand.  Dr.  Wallace  believes  that  with  moths  the 
progeny  from  a  second   or    tliird  fertilization    is  apt    to 
be  weakly,  and  therefore  would  not  have  so  good  chance 
of  surviving.     When   the  males  exist  in  much  greater 
numbers  than  the  females,  no  doubt  many  males  might 
be  destroyed  with  impunity  to  the  species  ;  but  I  cannot 
see  that  the  results  of  ordinary  selection  for  the  sake  of 
protection  would  be  influenced  by  the  sexes  existing  in 
unequal  numbers ;  for  the  same  pi'oportion  of  the  more 
conspicuous  individuals,  whether  males  or  females,  would 
probably  be  destroyed.     If,  indeed,  the  males  presented  a 
greater  range  of  variation  in  color,  the  result  would  be 
different ;  but  we  need  not  here  follow  out  such  complex 


391  SEXUAL   SELECTION.  [Part  IL 

details.  On  the  Avhole,  I  cannot  perceive  that  an  ine- 
quality in  the  numbers  of  the  two  sexes  would  influence 
in  any  marked  manner  the  effects  of  ordinary  selection  on 
the  character  of  the  offspring. 

Female  Lepidoptera  require,  as  Mr.  "Wallace  insists, 
some  days  to  deposit  their  fertilized  ova  and  to  search 
for  a  i^roper  place ;  during  this  period  (while  the  life  of 
the  male  was  of  no  importance)  the  brighter-colored  fe- 
males would  be  exposed  to  danger  and  would  be  liable  to 
be  destroyed.  The  duller-colored  females,  on  the  other 
hand,  would  survive,  and  thus  would  influence,  it  might  be 
thought,  in  a  marked  manner  the  character  of  the  species 
— either  of  both  sexes  or  of  one  sex,  accoi'ding  to  which 
form  of  inheritance  prevailed.  But  it  must  not  be  for- 
gotten that  the  males  emerge  from  the  cocoon-state  some 
days  before  the  females,  and  during  this  period,  while 
the  unborn  females  were  safe,  the  brighter-colored  males 
would  be  exposed  to  danger;  so  that  ultimately  both 
sexes  would  probably  be  exposed  during  a  nearly  equal 
length  of  time  to  danger,  and  the  elimination  of  conspicu- 
ous colors  would  not  be  much  more  effective  in  the  one 
than  tlie  other  sex. 

It  is  a  more  important  consideration  tliat  female  Le- 
pidoptera, as  Mr.  AVallace  remarks,  and  as  is  knov»'n  to 
every  collector,  are  generally  slower  flyers  than  the  males. 
Consequently  the  latter,  if  exposed  to  greater  danger 
from  being  conspicuously  colored,  might  be  able  to  escape 
from  their  enemies,  while  the  similarly-colored  females 
v.'ould  be  destroyed ;  and  thus  the  females  would  have  the 
most  influence  in  modifying  the  color  of  their  progeny. 

There  is  one  other  consideration :  bright  colors,  as  far 
as  sexual  selection  is  concerned,  are  commonly  of  no  ser- 
vice to  the  females  ;  so  that  if  the  latter  varied  in  bright- 
ness, and  the  variations  were  sexually  limited  in  their 
transmission,  it  Avould  depend  on  mere  chance  whether 


Chap.  XL]  BUTTERFLIES  AND   MOTHS.  395 

the  females  had  their  bright  colors  increased;  and  this 
.v/ould  tend  throughout  the  Order  to  diminish  the  number 
of  sj)ecies  with  brightly-colored  females  in  comjjarison 
with  the  species  having  brightly-colored  males.  On  the 
other  hand,  as  bright  colors  are  suj)posed  to  be  highly  ser- 
viceable to  the  males  in  their  love-struggles,  the  brighter 
males  (as  we  shall  see  in  the  chapter  on  Birds)  although 
exposed  to  rather  greater  danger,  would  on  an  average 
procreate  a  greater  number  of  offspring  than  the  duller 
males.  In  this  case,  if  the  variations  were  limited  in  their 
transmission  to  the  male  sex,  the  males  alone  would  be 
rendered  more  brilliantly  colored;  but  if  the  variations 
were  not  thus  limited,  the  preservation  and  augmentation 
of  such  variations  would  depend  on  whether  more  evil 
was  caused  to  the  species  by  the  females  being  rendered 
conspicuous,  than  good  to  the  males  by  certain  individuals 
being  successful  over  their  rivals. 

As  there  can  hardly  be  a  doubt  that  both  sexes  of 
many  butterflies  and  moths  have  been  rendered  dull-col- 
ored for  the  sake  of  protection,  so  it  may  have  been  with 
the  females  alone  of  some  species  in  which  successive 
variations  toward  dulness  first  appeared  in  the  female  sex, 
and  wex-e  from  the  first  limited  in  their  transmission  to 
the  same  sex.  If  not  thus  limited,  both  sexes  would  be- 
come dull-colored.  We  shall  immediately  see,  when  we 
treat  of  mimicry,  that  the  females  alone  of  certain  but- 
terflies have  been  rendered  extremely  beautiful  for  the 
sake  of  protection,  without  any  of  the  successive  protec- 
tive variations  having  been  transferred  to  the  male,  to 
vv^hoin  they  could  not  possibly  have  been  in  the  least  de- 
gree injurious,  and  therefore  could  not  have  been  elimi- 
nated through  natural  selection.  Whether  in  each  par- 
ticular species,  in  which  the  sexes  difler  in  color,  it  is  the 
female  Avhich  has  been  specially  modified  for  the  sake  of 
protection ;  or  whether  it  is  the  male  which  has  been  sj^c- 


396  SEXUAL  SELECTION.  [Pakt  IL 

cially  modified  for  the  sake  of  sexual  attraction,  the  fe- 
male having  retained  her  primordial  coloring  only  slightly 
changed  through  the  agencies  before  alluded  to ;  or 
whether  again  both  sexes  have  been  modified,  the  fe- 
male for  protection  and  the  male  for  sexual  attraction,  can 
only  be  definitely  decided  when  we  know  the  life-history 
of  each  species. 

Without  distinct  evidence,  I  am  unwilling  to  admit 
that  a  double  process  of  selection  has  long  been  going  on 
with  a  multitude  of  species — the  males  having  been  ren- 
dered more  brilliant  by  beating  their  rivals ;  and  the  fe- 
males more  dull-colored  by  having  escaped  from  their 
enemies.  "We  may  take  as  an  instance  the  common  brim- 
stone butterfly  (Gonepteryx),  which  appears  early  in  the 
spring  before  any  other  kind.  The  male  of  this  species  is 
of  a  far  more  intense  yellow  than  the  female,  though  she 
is  almost  equally  conspicuous ;  and  in  this  case  it  does 
not  seem  probable  that  she  specially  acquired  her  pale 
tints  as  a  protection,  though  it  is  probable  that  the  male 
acquired  his  bright  colors  as  a  sexual  attraction.  The  fe- 
male of  Anthocaris  cardamines  docs  not  possess  the  beau- 
tiful orange  tips  to  her  wings  with  which  the  male  is  or- 
namented ;  consequently  she  closely  resembles  the  white 
butterflies  (Pieris)  so  common  in  our  gardens ;  but  we 
have  no  evidence  that  this  resemblance  is  beneficial.  On 
the  contrary,  as  she  resembles  both  sexes  of  several  spe- 
cies of  the  same  genus  inhabiting  various  quarters  of  the 
world,  it  is  more  probable  that  she  has  simply  retained  to 
a  large  extent  her  primordial  colors. 

Various  facts  support  the  conclusion  that,  with  the 
greater  number  of  brilliantly-colored  Lepidoptera,  it  is  the 
male  which  has  been  modified;  the  two  sexes  having 
come  to  dificr  from  each  other,  or  to  resemble  each  other, 
according  to  which  form  of  inheritance  has  prevailed.  In- 
heritance is  governed  by  so  many  imknown  laws  or  con- 


CuAP.  XI.]  BUTTERFLIES  AND   MOTHS.  397 

ditions,  that  they  seem  to  us  to  be  most  capricious  in  their 
action ; "  and  we  can  so  far  understand  how  it  is  that  with 
closely-allied  si^ecies  the  sexes  of  some  differ  to  an  aston- 
ishing degree,  while  the  sexes  of  others  are  identical  in 
color.  As  the  successive  steps  in  the  process  of  variation 
are  necessarily  all  transmitted  through  the  female,  a 
greater  or  less  number  of  such  steps  might  readily  become 
developed  in  her ;  and  thus  we  can  understand  the  fre- 
quent gradations  from  an  extreme  difference  to  no  differ- 
ence at  all  between  the  sexes  of  the  species  within  the 
same  group.  These  cases  of  gradation  are  much  too  com- 
mon to  favor  the  supposition  that  we  here  see  females  ac- 
tually undergoing  the  process  of  transition  and  losing 
their  brightness  for  the  sake  of  protection  ;  for  we  have 
every  reason  to  conclude  that  at  any  one  time  the  greater 
number  of  species  are  in  a  fixed  condition.  With  respect 
to  the  differences  between  the  females  of  the  species  in 
the  same  genus  or  family,  we  can  perceive  that  they  de- 
pend, at  least  in  part,  on  the  females  partaking  of  the  col- 
ors of  their  respective  males.  This  is  well  illustrated  in 
those  groups  in  which  the  males  are  ornamented  to  an  ex- 
traordinary degree ;  for  the  females  in  these  groups  gener- 
ally partake  to  a  certain  extent  of  the  splendor  of  their 
male  partners.  Lastly,  we  continually  find,  as  already 
remarked,  that  the  females  of  almost  all  the  species  in  the 
same  genus,  or  even  family,  resemble  each  other  much 
more  closely  in  color  than  do  the  males ;  and  this  indi- 
cates that  the  males  have  undergone  a  greater  amount  of 
modification  than  the  females. 

Mhnicry. — This  principle  was  first  made  clear  in  an  ad- 
mirable paper  by  Mr.  Bates,"  who  thus  threv/  a  flood  of 

52  '  The  Variation  of  Animals  and  Plants  under  Domestication,'  vol.  ii. 
chap.  xii.  p.  lY. 

"  '  Transact.  Linn.  See.'  vol.  xxiii.  1862,  p.  405. 


398  SEXUAL  SELECTION.  [Part  H. 

light  on  many  obscure  problems.  It  bad  previously  been 
observed  tliat  certain  butterflies  in  South  America,  belong- 
ing to  quite  distinct  families,  resembled  the  Ileliconi- 
dce  so  closely,  in  every  stripe  and  shade  of  color,  that 
they  could  not  be  distinguished  except  by  an  experi- 
enced entomologist.  As  the  Heliconidje  are  colored  in 
their  usual  manner,  while  the  others  depart  from  the  usual 
coloring  of  the  grou2)S  to  which  they  belong,  it  is  clear 
that  the  latter  are  the  imitators,  and  the  Heliconidoe  the 
imitated.  Mr.  Bates  further  observed  that  the  imitating 
species  are  comparatively  rare,  while  the  imitated  swarm 
in  large  numbers;  the  two  sets  living  mingled  togeth- 
er. From  the  fact  of  the,  Heliconidse  being  conspicuous 
and  beautiful  insects,  yet  so  numerous  in  individuals  and 
species,  he  concluded  that  they  must  be  protected  from 
the  attacks  of  birds  by  some  secretion  or  odor ;  and  this 
hypothesis  has  now  been  confirmed  by  a  considerable 
body  of  curious  evidence.'^  From  these  considerations 
Mr.  Bates  inferred  that  the  butterflies  which  imitate  the 
protected  species  had  acquired  their  present  marvellously 
deceptive  appearance  through  variation  and  natural  se- 
lection, in  order  to  be  mistaken  for  the  protected  kinds 
and  thus  to  escape  being  devoiired.  ISTo  explanation  is 
here  attempted  of  the  brilliant  colors  of  the  imitated,  but 
only  of  the  imitating  butterflies.  We  must  account  for  the 
colors  of  the  former  in  the  same  general  manner  as  in 
the  cases  previously  discussed  in  this  chapter.  Since 
the  publication  of  Mr.  Bates's  paper,  similar  and  equally 
striking  facts  have  been  observed  by  Mr.  Wallace  ^''  in  the 
Malayan  region,  and  by  Mr.  Trimen  in  South  Africa, 
As  some  writers "'  have  felt  much  difficulty  in  under- 

"  '  Proc.  Ent.  Soc'  Dec.  3,  1866,  p.  xiv 

86 'Transact.  Linn.  Soc' vol.  xxv.   1805,  p.   1;  also  '  Transact.  Ent. 
Soc'  vol.  iv.  (3d  series),  1867,  p.  301. 

'^  See  an  in£rcnio\is  article  entitled  "  PifTiculties  of  the  Theory  of  Nat- 


Chap.  XI.]  BUTTERFLIES  AND   MOTHS.  399 

standing  how  the  first  steps  in  the  process  of  mimicry 
could  have  been  effected  through  natural  selection,  it  may 
be  v/ell  to  remark  that  the  process  probably  has  never 
commenced  with  forms  widely  dissimilar  in  color.  But, 
with  two  species  moderately  like  each  other,  the  closest 
resemblance,  if  beneficial  to  either  form,  could  readily  be 
thus  gained ;  and,  if  the  imitated  form  was  subsequently 
and  gradually  modified  through  sexual  selection  or  any 
other  means,  the  imitatino-  form  would  be  led  alonsc  the 
same  track,  and  thus  be  modified  to  almost  any  extent,  so 
that  it  might  ultimately  assume  an  appearance  or  coloring 
wholly  vmlike  that  of  the  other  members  of  the  group  to 
which  it  belonged.  As  extremely  slight  variations  in  col- 
or would  not  in  many  cases  sufiice  to  render  a  species  so 
like  another  protected  species  as  to  lead  to  its  preserva- 
tion, it  should  be  remembered  that  many  species  of  Lepi- 
doptera  are  liable  to  considerable  and  abrupt  variations  in 
color.  A  few  instances  have  been  given  in  this  chapter ; 
but  under  this  point  of  view  Mi*.  Bates's  original  j)aper 
on  mimicry,  as  well  as  Mr.  Wallace's  papers,  should  be 
consulted. 

In  the  foregoing  cases  both  sexes  of  the  imitating  spe- 
cies resemble  the  imitated ;  but  occasionally  the  female 
alone  mocks  a  brilliantly-colored  and  protected  species 
inhabiting  the  same  district.  Consequently  the  female 
differs  in  color  from  her  own  male,  and,  which  is  a  rare  and 
anomalous  circumstance,  is  the  more  brightly-colored  of  the 
two.  In  all  the  few  species  of  Pierida3,  in  which  the  female 
is  more  conspicuously  colored  than  the  male,  she  imitates, 

ural  Selection,"  in  the  'Month,'  1869.  The  writer  strangely  supposes 
that  I  attribute  the  variations  in  color  of  the  Lepidoptera,  by  which  cer- 
tain species  belonging  to  distinct  families  have  come  to  resemble  others, 
to  reversion  to  a  common  progenitor ;  but  there  is  no  more  reason  to 
attribute  these  variations  to  reversion  than  in  the  case  of  any  ordinary 
variation. 


(00  SEXUAL  SELECTION.  [Paut  II. 

as  I  am  informed  by  Mr.  Wallace,  some  protected  species 
inhabiting  the  same  region.  The  female  of  Diadema 
anomala  is  rich  purple-brown  with  almost  the  whole 
surface  glossed  with  satiny  blue,  and  she  closely  imitates 
the  Euploea  midanixis^  "  one  of  the  commonest  butter- 
flies of  the  East;"  while  the  male  is  bronzy  or  olive- 
brown,  with  only  a  slight  blue  gloss  on  the  outer  parts 
of  the  wings.''*  Both  sexes  of  this  Diadema  and  of  D. 
holina  follow  the  same  habits  of  life,  so  that  the  differ- 
ences in  color  between  the  sexes  cannot  be  accounted 
for  by  exposure  to  different  conditions  ;  ^'  even  if  this  ex- 
planation were  admissible  in  other  instances.'" 

The  above  cases,  of  female  butterflies  which  are  more 
brightly-colored  than  the  males,  show  us,  firstly,  that 
variations  have  arisen  in  a  state  of  nature  in  the  female 
sex,  and  have  been  transmitted  exclusively,  or  almost  ex- 
clusively, to  the  same  sex  ;  and,  secondly,  that  this  form 
of  iulieritance  has  not  been  determined  through  natural 
selection.  For,  if  we  assume  that  the  females,  before  they 
became  brightly  colored  in  imitation  of  some  protected 
kind,  were  exposed  during  each  season  for  a  longer  period 
to  danger  than  the  males,  or  if  we  assume  that  they 
could  not  escape  so  swiftly  from  their  enemies,  we  can 
understand  how  they  alone  might  originally  have  acquired 
through  natural  selection  and  sexually-limited  inheritance 
their  present  protective  colors.  But,  except  on  the  prin- 
ciple of  these  variations  having  been  transmitted  exclu- 
sively to  the  female  offspring,  we  cannot  understand  wliy 
the  males  should  have  remained  dull-colored;  for  it  would 

-8  Wallace,  "  Notes  on  Eastern  Butterflies,"  '  Transact.  Ent.  Soc' 
18G9,  p.  287. 

"^Wallace,  in  'Westminster  Kevicw,'  Jul)',  1SG7,  p.  3*7;  and  in 
'  Journal  of  Travel  and  Nat.  Hist.'  vol.  i.  1SG8,  p.  88. 

'"  See  remarks  by  Messrs.  Bates  and  Wallace,  in  '  Proc.  Ent.  Soc.' 
Nov.  10,  18GG,  p.  xsxix. 


Chap.  XI.]  BUTTERFLIES   AND   MOTHS.  401 

surely  not  have  been  in  any  way  injurious  to  each  indi- 
vidual male  to  have  partaken  by  inheritance  of  the  pro- 
tective colors  of  the  female,  and  thus  to  have  had  a  better 
chance  of  escaping  destruction.  In  a  group  in  which 
brilliant  colors  are  so  common  as  with  butterflies,  it  can- 
not be  supposed  that  the  males  have  been  kept  dull-col- 
ored through  sexual  selection  by  the  females  rejecting  the 
individuals  which  were  rendered  as  beautiful  as  them- 
selves. We  may,  therefore,  conclude  that  in  these  cases 
inheritance  by  one  sex  is  not  due  to  the  modification 
through  natural  selection  of  a  tendency  to  equal  inherit- 
ance by  both  sexes. 

It  may  be  well  here  to  give  an  analogous  case  in  an- 
otlier  Order,  of  characters  acquired  only  by  the  female, 
though  not  in  the  least  injurious,  as  far  as  we  can  judge, 
to  the  male.  Among  the  Phasmidoe,  or  spectre-insects, 
Mr.  Wallace  states  that  it  is  often  the  females  alone  that 
so  strikingly  resemble  loaves,  while  the  males  show  only 
a  rude  approximation."  Now,  whatever  may  be  the  hab- 
its of  these  insects,  it  is  highly  improbable  that  it  could 
be  disadvantageous  to  the  males  to  escape  detection  by 
resembling  leaves."      Hence  we  may  conclude  that  the 

2'  See  ilr.  Wallace  in  '  Westminster  Review,'  July,  186Y,  pp.  11,  37. 
The  male  of  no  butterfly,  as  Mr.  Wallace  informs  me,  is  known  to  differ  in 
color,  as  a  protection,  from  the  female ;  and  he  asks  me  how  I  can  ex- 
plain this  fact  on  the  principle  that  one  sex  alone  has  varied  and  has 
transmitted  its  variations  exclusively  to  the  same  sex,  without  the  aid  of 
selection  to  check  the  variations  being  inherited  by  the  other  sex.  No 
doubt,  if  it  could  be  shown  that  the  females  of  very  many  species  had  been 
rendered  beautiful  through  protective  mimicry,  but  that  this  has  never 
occurred  with  the  males,  it  would  be  a  serious  difficulty.  But  the  number 
of  cases  as  yet  known  hardly  suffices  for  fair  judgment.  We  can  see 
that  the  males,  from  having  the  power  of  flying  more  swiftly,  and  thus 
escaping  danger,  would  not  be  so  likely  as  the  females  to  have  had  their 
colors  modified  for  the  sake  of  protection ;  but  this  would  not  in  the 
least  have  interfered  with  their  receiving  protective  colors  through  in- 

18 


402  SEXUAL  SELECTION.  [1>aut  II. 

females  alone  in  this  latter  as  iu  the  previous  cases  origi- 
nally varied  in  certain  characters ;  these  characters  hav- 
ing been  preserved  and  augmented  tlirough  ordinary  se- 
lection for  the  sake  of  protection,  and  from  the  first  trans- 
mitted to  the  female  offspring  alone. 

Bright  Colors  of  Caterpillars. — "While  reflecting  on 
the  beauty  of  many  butterflies,  it  occurred  to  me  that 
some  caterpillars  were-  splendidly  colored,  and  as  sexual 
selection  could  not  possibly  have  liere  acted,  it  appeared 
rash  to  attribute  the  beauty  of  the  mature  insect  to  this 
agency,  unless  the  bright  colors  of  their  larvre  could  be  in 
some  manner  explained.  In  the  first  jilacc,  it  may  be  ob- 
served that  the  colors  of  caterpillars  do  not  stand  in  any 
close  correlation  with  those  of  the  mature  insect.  Sec- 
ondly, their  bright  colors  do  not  serve  in  any  ordinary 
manner  as  a  protection.  As  an  instance  of  this,  Mr.  Bates 
informs  me  that  the  most  conspicuous  caterpillar  which  he 
ever  beheld  (that  of  a  Sphinx)  lived  on  the  large  green 
leaves  of  a  tree  on  the  oj^en  llanos  of  South  America ;  it 
was  about  four  inches  in  length,  transversely  banded  with 
black  and  yellow,  and  with  its  head,  legs,  and  tail  of  a 
bright  red.     Hence  it  cauglit  the  eye  of  any  man  who 

heritance  fi-om  the  females.  In  the  second  place,  it  is  probable  that 
sexual  selection  would  actually  tend  to  prevent  a  beautiful  male  from 
becoming  obscure,  for  the  less  brilliant  individuals  would  be  less  attrac- 
tive to  the  females.  Supposing  that  the  beauty  of  the  male  of  any  species 
had  been  mainly  acquired  through  sexual  selection,  yet  if  this  beauty 
likewise  served  as  a  protection,  the  acquisition  would  have  been  aided 
by  natural  selection.  But  it  would  be  quite  beyond  our  power  to  dis- 
tinguish between  the  two  processes  of  sexual  and  ordinary  selection. 
Hence  it  is  not  likely  that  wo  should  be  able  to  adduce  cases  of  the  males 
having  been  rendered  brilliant  exclusively  through  protective  mimicry, 
though  this  is  comparatively  easy  with  the  females,  which  have  rarely  or 
never  been  rendered  beautiful,  as  far  as  we  can  judge,  for  the  sake  of 
sexual  attraction,  although  they  have  often  received  beauty  through  in- 
heritance from  their  male  parents. 


Chap.  XL]  BUTTERFLIES  AND   MOTHS.  403 

passed  by  at  the  distance  of  many  yards,  and  no  doubt  of 
every  passing  bird. 

I  then  applied  to  Mr.  Wallace,  who  has  an  innate 
genius  for  solving  difficulties.  After  some  consideration 
he  replied :  "  Most  caterpillars  require  protection,  as  may 
be  inferred  from  some  kinds  being  furnished  with  spines 
or  irritating  hairs,  and  from  many  being  colored  green  like 
the  leaves  on  which  they  feed,  or  curiously  like  the  twigs 
of  the  ti-ees  on  which  they  live."  I  may  add  as  another 
instance  of  protection,  that  there  is  a  caterpillar  of  a  moth, 
as  I  am  informed  by  Mr.  J.  Mansel  Weale,  which  lives  on 
the  mimosas  in  South  Africa,  and  fabricates  for  itself  a 
case,  quite  undistinguishable  from  the  surrounding  thorns. 
From  such  consideration  Mr.  Wallace  thought  it  probable 
that  conspicuously-colored  caterpillars  were  protected  by 
having  a  nauseous  taste ;  but  as  their  skin  is  extremely 
tender,  and  as  their  intestines  readily  protrude  from  a 
wound,  a  slight  peck  from  the  beak  of  a  bird  would  be  as 
fatal  to  them  as  if  they  had  been  devoured.  Hence,  as 
Mr.  Wallace  remarks,  "  distastefulness  alone  would  be  in- 
sufficient to  protect  a  cateri^illar  unless  some  outward  sign 
indicated  to  its  would-be  destroyer  that  its  prey  was  a  dis- 
gusting morsel."  Under  these  circumstances  it  would 
be  highly  advantageous  to  a  caterpillar  to  be  instanta- 
neously and  certainly  recognized  as  unpalatable  by  all 
birds  and  other  animals.  Thus  the  most  gaudy  colors 
would  be  serviceable,  and  might  have  been  gained  by 
variation  and  the  survival  of  the  most  easily-recognized 
individuals. 

This  hypothesis  appears  at  first  sight  very  bold ;  but 
when  it  was  brought  before  the  Entomological  Society  ''^ 
it  was  supported  by  various  statements ;  and  Mr.  J.  Jen- 
ner  Weir,  who  keeps  a  large  number  of  birds  in  an  aviary, 

'2  'Proc.  Entomolog.  Soc'  Dec.  3,  1866,  p.  xlv.,  and  March  4,  1867, 
p.  Ixxx. 


404  SEXUAL   SELECTION.  [Part  II. 

has  made,  as  he  iulbrms  me,  numerous  trials,  and  finds  no 
exception  to  the  rule,  that  all  caterpillars  of  nocturnal  and 
retiring  habits  Vv'ith  smooth  skins,  all  of  a  green  color,  and 
all  Avhicli  imitate  twigs,  arc  greedily  devom-ed  by  his  birds. 
The  liairy  and  spinose  kinds  are  invariably  rejected,  as 
were  four  conspicuously-colored  species.  AVhen  the  birds 
rejected  a  caterpillar,  they  plainly  showed,  by  shaking 
their  heads  and  cleansing  their  beaks,  that  they  were  dis- 
gusted by  the  taste."  Three  conspicuous  kinds  of  caterpil- 
lars and  moths  were  also  given  by  Mr.  A.  Butler  to  some 
lizards  and  frogs,  and  were  rejected  ;  though  other  kinds 
v>'ere  eagerly  eaten.  Thus  the  probable  truth  of  xflr.  Wal- 
lace's view  is  confirmed,  namely,  that  certain  caterpillars 
have  been  made  conspicuous  for  their  own  good,  so  as  lo 
be  easily  recognized  by  their  enemies,  on  nearly  the  same 
principle  that  certain  poisons  are  colored  by  druggists  for 
the  good  of  man.  This  view  will,  it  is  probable,  be  here- 
after extended  to  many  animals,  which  are  colored  in  a 
conspicuous  manner. 

Summary  and  Concluding  Memarlcs  on  Insects. — 
Looking  back  to  the  several  Orders,  we  haA^e  seen  that 
the  sexes  often  difl;er  in  various  characters,  the  meaning 
of  which  is  not  understood.  The  sexes,  also,  often  differ 
in  their  organs  of  sense  or  locomotion,  so  that  the  males 
may  quickly  discover  or  reacli  the  females,  and  still  oftcncr 
in  the  males  possessing  diversified  contrivances  for  retairi- 
ing  the  females  when  found.  But  we  are  not  here  much 
concerned  with  sexual  differences  of  these  kinds. 

In  almost  all  the  Orders,  the  males  of  some  species, 
even  of  weak  and  delicate  kinds,  arc  known  to  be  highly 
pugnacious ;  and  some  few  are  furnished  with  special  weap- 
ons for  fighting  with  their  rivals.     But  the  law  of  battle 

"^  See  Mr.  J.  Jenner  Weirs  paper  on  insects  and  insectivorous  birds, 
in  'Transact.  Ent.  Soc'  1860,  p.  21  ;  also  Mr.  Butler's  paper,  ibid.  p.  27. 


Chap.  XL]  SUMMARY   OX   INSECTS.  405 

does  uot  prevail  nearly  so  widely  with  insects  as  with  the 
higher  animals.  Hence  probably  it  is  that  the  males  have 
not  often  been  rendered  larger  and  stronger  than  the  fe- 
males. On  the  contrary,  they  ai*e  nsually  smaller,  in  order 
that  they  may  be  developed  within  a  shorter  time,  so  as  to 
be  ready  in  large  numbers  for  the  emergence  of  the 
females. 

In  two  families  of  the  Homoptera  the  males  alone  pos- 
sess, in  an  efficient  state,  organs  which  may  be  called  vo- 
cal ;  and  in  three  families  of  the  Orthoptera  the  males  alone 
possess  stridulating  organs.  In  both  cases  these  organs 
are  incessantly  used  during  the  breeding-season,  not  only 
for  calling  the  females,  but  for  charming  or  exciting  them 
in  rivalry  with  other  males.  No  one,  who  admits  the  agen- 
cy of  natural  selection,  will  dispute  that  theSe  musical 
instruments  have  been  acquired  through  sexual  selection. 
In  four  other  Orders  the  members  of  one  sex,  or  more 
commonly  of  both  sexes,  are  provided  with  organs  for 
producing  various  sounds,  which  apparently  serve  merely 
as  call-notes.  Even  when  both  sexes  are  thus  provided, 
the  individuals  which  were  able  to  make  the  loudest  or 
most  continuous  noise  would  gain  partners  before  those 
which  were  less  noisy,  so  that  their  organs  have  probably 
been  gained  through  sexual  selection.  It  is  instructive  to 
reflect  on  the  wonderful  diversity  of  the  means  for  produ- 
cing sound,  possessed  by  the  males  alone  or  by  both  sexes 
in  no  less  than  six  Orders,  and  which  were  possessed  by  at 
least  one  insect  at  an  extremely  remote  geological  epoch. 
We  thus  learn  how  effectual  sexual  selection  has  been  in 
leading  to  modifications  of  structure,  which  sometimes,  as 
with  the  Homoptera,  are  of  an  important  nature. 

For  the  reasons  assigned  in  the  last  chapter,  it  is  prob- 
able that  the  great  horns  of  the  males  of  many  lamellicorn, 
and  some  other  beetles,  have  been  acquired  as  ornaments. 
So  perhaps  it  may  be  with  certain  other  peculiarities  con- 


400  SEXUAL  SELECTION.  [Part  IL 

lined  to  the  male  sex.  From  the  small  yize  of  insects,  we 
are  apt  to  undervalue  their  appearance.  If  we  could  im- 
agine a  male  Chalcosoma  (fig.  15)  with  its  polished, bronzed 
coat-of-mail,  and  vast  complex  horns,  magnified  to  the 
size  of  a  horse  or  even  of  a  dog,  it  would  be  one  of  the 
most  imposing  animals  in  the  world. 

The  coloring  of  insects  is  a  complex  and  obscure  sub- 
ject. When  the  male  difibrs  slightly  from  the  female, 
and  neither  is  brilliantly  colored,  it  is  probable  that  the 
two  sexes  have  varied  in  a  slightly  difterent  manner,  with 
the  variations  transmitted  to  the  same  sex,  without  any 
benefit  having  been  thus  derived  or  evil  suffered.  When 
the  male  is  brilliantly  colored  and  differs  conspicuously 
from  the  female,  as  with  some  dragon-flies  and  many  but- 
terflies, it  IS  probable  that  he  alone  has  been  modified,  and 
tliat  he  owes  his  colors  to  sexual  selection ;  while  the  fe- 
male has  retained  a  primordial  or  very  ancient  type  of 
coloring,  slightly  modified  by  the  agencies  before  explained, 
and  has  therefore  not  been  rendered  obscure,  at  least  in 
most  cases,  for  the  sake  of  protection.  But  the  female 
alone  has  sometimes  been  colored  brilliantly  so  as  to  imi- 
tate other  protected  species  inhabiting  the  same  district. 
When  the  sexes  resemble  each  other  and  both  are  obscure- 
ly colored,  there  is  no  doubt  that  they  have  been  in  a 
miiltitude  of  cases  colored  for  the  sake  of  protection.  So 
it  is  in  some  instances  when  both  are  brightly  colored, 
causing  them  to  resemble  surrounding  objects  such  as 
flowers,  or  other  protected  species,  or  indirectly  by  giving 
notice  to  their  enemies  that  they  are  of  an  unpalatable 
nature.  In  many  other  cases  in  which  the  sexes  resemble 
each  other  and  are  brilliantly  colored,  especially  when  the 
colors  are  arranged  for  display,  we  may  conclude  that  they 
have  been  gained  by  the  male  sex  as  an  attraction,  and 
have  been  transferred  to  both  sexes.  We  are  more  es- 
pecially led  to  this  conclusion  whenever  the  same  type  of 


Chap.  XL]  SUMMARY   ON   INSECTS.  407 

^^loration  prevails  throughout  a  group,  aud  we  find  that 
the  males  of  some  species  differ  widely  in  color  from  the 
females,  while  both  sexes  of  other  species  are  quite  alike, 
with  intermediate  gradations  connecting  these  extreme 
states. 

In  the  same  manner  as  bright  colors  have  often  been 
partially  transferred  from  the  males  to  the  females,  so  it 
has  been  with  the  extraordinary  horns  of  many  lamellicorn 
and  some  other  beetles.  So,  again,  the  vocal  or  instru- 
mental organs  proper  to  the  males  of  the  Homoptera  and 
Orthoptera  have  generally  been  transferred  in  a  rudimen- 
tary, or  even  in  a  nearly  perfect  condition  to  the  females ; 
yet  not  sufficiently  i:)erfect  to  be  used  for  producing  sound. 
It  is  also  an  interesting  fact,  as  bearing  on  sexual  selec- 
tion, that  the  stridulating  organs  of  certain  male  Orthop- 
tera are  not  fully  developed  until  the  last  moult ;  and  that 
the  colors  of  certain  male  dragon-flies  are  not  fully  devel- 
oped until  some  little  time  after  their  emergence  from  the 
pupal  state,  and  when  they  are  ready  to  breed. 

Sexual  selection  implies  that  the  more  attractive  indi- 
viduals are  preferred  by  the  opposite  sex ;  and  as  with  in- 
sects, when  the  sexes  differ,  it  is  the  male  whicli,  with 
rare  exceptions,  is  the  most  ornamented  and  departs  most 
from  the  type  to  wliich  the  species  belongs,  and  as  it  is 
the  male  which  searches  eagerly  for  the  female,  we  must 
suppose  that  the  females  habitually  or  occasionally  prefer 
the  more  beautiful  males,  and  that  these  have  thus  ac- 
quired their  beauty.  That  in  most  or  all  the  orders  the 
females  have  the  power  of  rejecting  any  particular  male, 
we  may  safely  infer  from  the  many  singular  contrivances 
})0ssessed  by  the  males,  such  as  great  jaws,  adhesive 
cushions,  spines,  elongated  legs,  etc.,  for  seizing  the 
female ;  for  these  contrivances  show  that  there  is  some 
difficulty  in  the  act.  In  the  case  of  unions  between  dis- 
tinct species,  of  which  many  instances  have  been  recorded, 


408  SEXUAL  SELECTION.  [Part  IL 

the  female  must  have  been  a  consenting  party.  Judging 
from  what  we  know  of  the  perceptive  powers  and  aifec- 
tions  of  various  insects,  there  is  no  antecedent  improba- 
bility in  sexual  selection  having  come  largely  into  action ; 
but  we  have  as  yet  no  direct  evidence  on  this  head,  and 
some  facts  are  opposed  to  the  belief.  Nevertheless,  when 
we  sec  many  males  pursuing  the  same  female,  Ave  can 
hardly  believe  that  the  jjairing  is  left  to  blind  chance — 
that  the  female  exerts  no  choice,  and  is  not  influenced  by 
the  gorgeous  colors  or  other  ornaments  with  which  the 
male  alone  is  decorated. 

If  we  admit  that  the  females  of  the  Homoptera  and 
Orthoptera  appreciate  the  musical  tones  emitted  by  their 
male  partners,  and  that  the  various  instruments  for  this 
purpose  have  been  perfected  through  sexual  selection, 
there  is  little  improbability  in  the  females  of  other  insects 
appreciating  beauty  in  form  or  color,  and  consequently  in 
such  characters  having  been  thus  gained  by  the  males. 
But,  from  the  circumstance  of  color  being  so  variable,  and 
from  its  having  been  so  often  modified  for  the  sake  of  pro- 
tection, it  is  extremely  difficult  to  decide  in  how  large  a 
proportion  of  cases  sexual  selection  has  come  into  play. 
This  is  more  especially  difiicult  in  those  Orders  such  as  the 
Ox'thoptera,  Hymcnoptera,  and  Coleoptera,  in  which  the 
two  sexes  rarely  differ  much  in  color ;  for  Ave  are  thus  cut 
off  from  our  best  evidence  of  some  relation  between  the 
reproduction  of  the  species  and  color.  With  the  Coleop- 
tera, however,  as  before  remarked,  it  is  in  the  great  lamel- 
licorn  group,  placed  by  some  authors  at  the  head  of  tlie 
Order,  and  in  Avhich  we  sometimes  see  a  mutual  attach- 
ment between  the  sexes,  tliat  Ave  find  the  males  of  some 
species  possessing  Aveapons  for  sexual  strife,  others  fur- 
nished with  Avonderful  horns,  many  Avith  stridulating  or- 
gans, and  others  ornamented  Avith  splendid  metallic  tints. 
Hence  it  seems  probable  that  all  these  characters  have 


CxiAP.  XL]  SUMMARY   ON   INSECTS.  409 

been  gained  though  the  same  means,  namely,  sexual  selec- 
tion. 

When  v/e  treat  of  Birds,  we  shall  see  that  they  pre- 
sent in  their  secondary  sexual  characters  the  closest  anal- 
ogy with  insects.  Thus,  many  male  birds  are  highly  pug- 
nacious, and  some  are  furnished  with  special  weapons  for 
ligliting  with  their  rivals.  They  possess  organs  which  are 
used  during  the  breeding-season  for  producing  vocal  and 
instrumental  music.  They  are  frequently  ornamented 
with  combs,  horns,  wattles,  and  plumes,  of  the  most  diver- 
sified kinds,  and  are  decorated  with  beautiful  colors,  all 
evidently  for  the  sake  of  display.  We  shall  find  that,  as 
with  insects,  both  sexes,  in  certain  groups,  are  equally 
beautiful,  and  are  equally  provided  with  ornaments  which 
are  usually  confined  to  the  male  sex.  In  other  groups 
both  sexes  are  equally  plain-colored  and  imornamented. 
Lastly,  in  some  few  anomalous  cases,  the  females  are  more 
beautiful  than  the  males.  We  shall  often  find,  in  the 
same  group  of  birds,  every  gradation  from  no  difierence 
between  the  sexes  to  an  extreme  difierence.  In  the  latter 
case  we  shall  see  that  the  females,  like  female  insects,  often 
possess  more  or  less  plain  traces  of  the  characters  which 
properly  belong  to  the  males.  The  analogy,  indeed,  in  all 
these  I'espects,  between  birds  and  insects,  is  curiously 
close.  Whatever  explanation  applies  to  the  one  class 
probably  applies  to  the  other ;  and  this  explanation,  as  we 
shall  hereafter  attempt  to  show,  is  almost  certainly  sexual 
selection. 


END    OF   VOL.    I. 


THE  ORIGIN  OF  SPECIES, 

By  CHARLES  DARWIN. 


A  new  American  edition  of  "The  Origin  of  Species,"  later  than  the  latest 
English  edition,  has  just  been  published,  with  the  author's  most  recent  cor- 
rections and  additions. 

In  the  whole  history  of  the  progress  of  knowledge  there  is  no  case  so  re- 
markable of  a  system  of  doctrines,  at  first  generally  condemned  as  false  and 
absurd,  coming  into  general  acceptance  in  the  scientific  world  in  a  single 
decade.  From  the  following  statements,  the  reader  will  infer  the  estimate 
that  is  now  placed  upon  the  man  and  his  works  by  the  highest  authorities. 

"  Personally  and  practically  exercised  in  zoology,  in  minute  anatomy,  in 
geology ;  a  student  of  geographical  distribution,  not  on  maps  and  in  museums 
only,  but  by  long  voyages  and  laborious  collection  ;  having  largely  advanced 
each  of  these  branches  of  science,  and  having  spent  many  years  in  gathering 
and  sifting  materials  for  his  present  work,  the  store  of  accurately-registereil 
facts  upon  which  the  author  of  the  'Origin  of  Species'  is  able  to  draw  at 
will  is  prodigious."^Prof.  T.  H.  Huxley. 

"  Far  abler  men  than  myself  may  confess  tliat  they  have  not  that  imtiring 
patience  in  accumulating,  and  that  wonderful  skill  in  using,  large  masses  of 
facts  of  the  most  varied  kind — that  wide  and  accurate  physiological  knowl- 
edge— that  acuteness  in  devising,  that  skill  in  carrying  out  experiments,  and 
that  admirable  style  of  cc;i;position,  at  once  clear,  persuasive,  and  judicial, 
qualities  which,  in  their  harmonious  combination,  mark  out  Mr.  Darwin  as 
the  man,  perhaps  of  all  men  now  living,  best  fitted  for  the  great  work  he 
has  undertaken  and  accomplished." — Alfeed  Russell  Wallace. 

In  Germany  these  views  are  rapidly  extending.  Prof.  Giekie,  a  distin- 
guished British  geologist,  attended  the  recent  Congress  of  German  Natural- 
ists and  Physicians,  at  Innspruck,  in  which  some  eight  hundred  savants 
were  present,  and  thus  writes : 

"What  specially  struck  me  was  the  universal  sway  which  the  writings 
of  Darwin  now  exercise  over  the  German  mind.  You  see  it  on  every  side,  in 
private  conversation,  in  printed  papers,  in  all  the  many  sections  into  which 
such  a  meeting  as  that  at  Innspruck  divides.  Darwin's  name  is  often  men- 
tioned, and  always  with  the  profoundcst  veneration.  But  even  where  no  al- 
lusion is  specially  made  to  him,  nay,  even  more  markedly,  where  such  allusion 
is  absent,  we  see  how  thoroughly  his  doctrines  have  permeated  the  scientific 
min'd,  even  in  those  departments  of  knowledge  which  might  seem  at  first 
sight  to  be  farthest  from  natural  history.  '  You  are  still  discussing  in  Eng- 
land,' said  a  German  friend  to  me,  '  whether  or  not  the  tlieory  of  Darwin  can 
be  true.  "We  have  got  a  long  way  beyond  that  here.  His  theory  is  now  our 
common  starting-point.'  And,  so  far  as  my  experience  went,  I  found  it  to 
be  so." 

U.    ^T'FLElTOISr    &;    CO..    r>Taljlisliers. 


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