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C^p^v^    A    ' 
1  ^ 

a.  a 


TEE  STOKY  OF  THE  PLANTS. 


a 

THE   STOEY  OF 

THE    PLANTS. 


GEANT     ALLEN. 

—•3 

M 


o>* 
3^ 


WITH   ILLUSTRATIONS. 


LONDON:    GEORGE    NEWNES,   LTD. 

SOUTHAMPTON     STREET,     STRAND 

1895 


The  rights  of  translation  and  of  reproduction  are  reserved. 


PREFACE. 


IN  this  little  volume  I  have  endeavoured  to  give 
a  short  and  succinct  account  of  the  principal 
phenomena  of  plant  life,  in  language  suited  to 
the  comprehension  of  unscientific  readers.  As 
far  as  possible  I  have  avoided  technical  terms 
and  minute  detail,  while  I  have  tried  to  adopt  a 
more  philosophical  tone  than  is  usually  employed 
in  elementary  works.  I  have  treated  my  readers, 
not  as  children,  but  as  men  and  women,  endowed 
with  the  average  amount  of  intelligence  and 
insight,  and  anxious  to  obtain  some  sensible 
information  about  the  world  of  plants  which 
exists  all  round  them.  Acting  upon  this  basis, 
I  have  freely  admitted  the  main  results  of  the 
latest  investigations,  accepting  throughout  the 
evolutionary  theory,  and  making  the  study  of 
plants  a  first  introduction  to  the  great  modern 
principles  of  heredity,  variation,  natural  selec- 
tion, and  adaptation  to  the  environment.  Hence 
I  have  wasted  comparatively  little  space  on 
mere  structural  detail,  and  have  dwelt  as  much 
as  possible  on  those  more  interesting  features 
in  the  interrelation  of  the  plant  and  animal 
worlds  which  have  vivified  for  us  of  late  years 
the  dry  bones  of  the  old  technical  botany. 

My  principle  has  been  to  unfold  my  subject 
by  gradual  stages,  telling  the  reader  one  thing 
at  a  time,  and  building  up  by  degrees  his  know- 


i 


D  PREFACE. 

ledge  of  the  subject.  My  treatment  is,  therefore, 
to  some  extent  diagrammatic,  especially  in  the 
earlier  chapters  ;  but  I  endeavour  as  I  proceed 
to  correct  the  generalisations  and  fill  in  the 
gaps  of  the  first  crude  statement.  I  trust  that 
advanced  students  who  may  glance  at  this  little 
book  will  forgive  me  for  such  concessions  to  the 
weaker  brethren,  especially  when  they  see  that 
at  the  same  time  I  have  ventured  to  lay  before 
untechnical  readers  all  the  latest  results  of  the 
most  advanced  botanical  research,  as  far  as 
could  be  done  in  so  small  a  compass.  I  have 
even  made  bold  to  speak  at  times  of  "carbonic 
acid,"  where  I  ought  strictly  to  have  said 
"Carbon  dioxide."  and  to  glide  gently  over  the 
distinction  between  hydro-carbons  and  carbo- 
hydrates, which  could  interest  none  but  chemical 
students.  I  have  been  well  content  to  make 
these  trivial  sacrifices  of  formal  accuracy  in 
order  to  find  room  for  fuller  exposition  of  the 
delightful  relations  between  flowers  and  insects, 
birds  and  fruits,  soil  and  pla*it,  climate  and 
foliage.  In  one  word,  I  have  dwelt  more  on 
the  functions  and  habits  of  plants  than  on  their 
structure  and  classification.  At  the  same  time 
I  have  tried  to  lead  on  my  reader  by  gradual 
stages  to  the  further  study  of  plants  in  the 
concrete ;  and  I  shall  be  disappointed  if  my 
little  book  does  not  induce  a  considerable  pro- 
portion of  those  into  whose  hands  it  may  fall 
to  pursue  the  subject  further  in  our  fields  and 
woods  by  the  aid  of  a  Flora. 

G.  A. 

THE  CROFT,  HINDHEAD. 
April,  1895. 


CONTENTS. 


CHAP.  PAGE 

I.    INTRODUCTORY        .....  9 

II.    HOW   PLANTS   BEGAN    TO    BE    .                  .                  .  14 

III.  HOW  PLANTS  CAME  TO  DIFFER  FROM   ONE   ANOTHER  26 

IV.  HOW   PLANTS    EAT         ....  35 
V.    HOW    PLANTS   DRINK             .                 .                  .                  ,57 

VI.    HOW   PLANTS   MARRY  .                  .                  .  78 

VII.    VARIOUS    MARRIAGE    CUSTOMS  .  .  .93 

VIII.    MORE    MARRIAGE    CUSTOMS        .                  .                  .  113 

IX.    THE    WIND   AS   CARRIER        ....  135 

X.    HOW   FLOWERS    CLUB   TOGETHER            .                  .  147 

XI.    WHAT    PLANTS    DO   FOR   THEIR   YOUNG           .                  .  162 

XII.    THE    STEM  AND   BRANCHES       .                 .                  -  176 

XIII.    SOME   PLANT   BIOGRAPHIES                  .                  .                  .  198 

XIV.   THE   PAST    HISTORY   OF   PLANTS              .                 .  221 


CHAPTEE  I. 

INTRODUCTORY. 

I  PROPOSE  in  this  volume  to  write  in  brief  the 
history  of  plants,  their  origin  and  their  develop- 
ment. I  shall  deal  with  them  all,  both  big  and 
little,  from  the  cedar  that  is  in  Lebanon  to  the 
hyssop  that  springeth  out  of  the  wall.  I  shall 
endeavour  to  show  how  they  first  came  into 
existence,  and  by  what  slow  degrees  they  have 
been  altered  and  moulded  into  the  immense 
variety  of  tree,  shrub,  and  herb,  palm,  mush- 
room, and  sea- weed  we  now  behold  before  us. 
In  short,  I  shall  treat  the  history  of  plants  much 
as  one  treats  the  history  of  a  nation,  beginning 
with  their  simple  and  unobtrusive  origin,  and 
tracing  them  up  through  varying  stages  to  their 
highest  point  of  beauty  and  efficiency. 

Plants  are  living  things.  That  is  the  first 
idea  we  must  clearly  form  about  them.  They 
are  living  in  just  the  same  sense  that  you  and 
I  are.  They  were  born  from  a  seed,  the  joint 
product  of  two  previous  individuals,  their  father 
and  mother.  Plants  likewise  live  by  eating ; 
they  have  mouths  and  stomachs,  which  devour, 
digest,  and  assimilate  the  food  supplied  to  them. 
These  mouths  and  stomachs  exist  in  the  shape  of 
leaves,  whose  business  it  is  to  catch  floating 


10        THE  STORY  OF  THE  PLANTS. 

particles  of  carbonic  acid  in  the  air  around,  to 
suck  such  particles  in  by  means  of  countless 
lips,  and  to  extract  from  them  the  carbon  which 
is  the  principal  food  and  raw  material  of  plant 
life.  Plants  also  drink,  but,  unlike  ourselves, 
they  have  quite  different  mouths  to  eat  with  and 
to  drink  with.  They  take  in  their  more  solid 
constituent,  carbon,  with  their  leaves  from  the 
air ;  but  they  take  in  their  liquid  constituent, 
water,  with  their  roots  and  rootlets  from  the  soil 
beneath  them.  "  More  solid,"  I  say,  because 
the  greater  part  of  the  wood  and  harder  tissues 
of  plants  is  made  up  of  carbon,  in  combination 
with  other  less  important  materials ;  though, 
when  the  plants  eat  this  carbon,  it  is  not  in  the 
solid  form,  but  in  the  shape  of  a  gas,  carbonic 
acid,  as  I  shall  more  fully  explain  when  we  come 
to  consider  this  subject  in  detail,  For  the 
present,  it  will  be  enough  to  remember  that 
Plants  are  living  things,  which  eat  and  drink 
exactly  as  we  ourselves  do. 

Plants  also  marry  and  rear  families.  They 
have  two  distinct  sexes,  male  and  female — 
sometimes  separated  on  different  plants,  but 
more  often  united  on  the  same  stem,  or  even 
combined  in  the  same  flower.  For  flowers  are 
the  reproductive  parts  of  plants  ;  they  are  there 
for  the  purpose  of  producing  the  seeds,  from 
which  new  plants  spring,  and  by  means  of  which 
each  kind  is  perpetuated.  The  male  portions  of 
plants  of  the  higher  types  are  known  as  stamens , 
they  shed  a  yellow  powder  which  we  call  pollen, 
and  this  powder  has  a  fertilising  influence  on 
the  young  seeds  or  ovules.  The  female  portion 


INTRODUCTORY.  11 

of  plants  of  the  higher  types  is  known  as  the 
pistil ;  it  contains  tiny  undeveloped  knobs  or 
ovules,  which  can  only  swell  out  and  grow  into 
fruitful  seeds  provided  they  have  been  fertilised 
by  pollen  from  the  stamens  of  their  own  or  some 
other  flower.  The  ovules  thus  answer  very 
closely  to  the  eggs  of  animals.  After  they  have 
been  fertilised,  the  pistil  begins  to  mature  into 
what  we  call  a  fruit,  which  is  sometimes  a  sweet 
and  juicy  berry,  as  in  the  gr,ape  or  the  currant, 
but  more  often  a  dry  capsule,  as  in  the  poppy  or 
the  violet. 

Plants,  however,  unlike  animals,  are  usually 
fixed  and  rooted  to  one  spot.  This  makes  it 
practically  impossible  for  them  to  go  in  search 
of  mates,  like  birds  or  butterflies,  squirrels  or 
weasels.  So  they  are  obliged  to  depend  upon 
outside  agencies,  not  themselves,  for  the  con- 
veyance of  pollen  from  one  flower  to  another. 
Sometimes,  in  particular  plants,  such  as  the 
hazels  and  grasses,  it  is  the  wind  that  carries 
the  pollen  on  its  wings  from  one  blossom  to  its 
neighbour ;  and,  in  this  case,  the  stamens  which 
shed  the  pollen  hang  out  freely  to  the  breeze, 
while  the  pistil,  which  is  to  catch  it,  is  provided 
with  numberless  little  feathery  tails  to  receive 
the  passing  grains  of  fertilising  powder.  But 
oftener  still,  it  is  insects  that  perform  this  kind 
office  for  the  plant,  as  in  the  dog-rose,  the  holly- 
hock, and  the  greater  part  of  our  beautiful  garden 
flowers.  In  such  cases  the  plant  usually  makes 
its  blossom  very  attractive  with  bright-coloured 
petals,  so  as  to  allure  the  insect,  while  it  repays 
.him  for  his  trouble  in  carrying  a\vay  the  pollen 


12        THE  STOKY  OF  THE  PLANTS. 

by  giving  him  in  return  a  drop  of  honey.  The 
bee  or  butterfly  goes  there,  of  course,  for  the 
honey  alone,  unconscious  that  he  is  aiding  the 
plant  to  set  its  seeds;  but  the  plant  puts  the 
honey  there  in  order  to  entice  him  against  his 
will  to  transport  the  fertilising  powder  from 
flower  to  flower.  There  is  no  more  fascinating 
chapter  in  the  great  book  of  life  than  that  which 
deals  with  these  marriage  relations  of  the  flowers 
and  insects,  and  I  shall  explain  at  some  detail  in 
later  portions  of  this  little  work  some  of  the  most 
curious  and  interesting  of  such  devices. 

Again,  after  the  plant  has  had  its  flower 
fertilised,  and  has  set  its  seed,  it  has  to  place 
its  young  ones  out  in  the  world  to  the  greatest 
advantage.  If  it  merely  drops  them  under  its 
own  branches,  they  may  not  thrive  at  all;  it 
may  have  impoverished  the  soil  already  of  certain 
things  which  are  necessary  for  that  particular 
kind,  owing  to  causes  to  be  explained  hereafter ; 
and  even  where  this  is  not  the  case,  the  sur- 
rounding soil  may  be  so  fully  occupied  by  other 
plants  that  the  poor  little  seedlings  get  no 
chance  of  establishing  themselves.  To  meet 
such  emergencies,  plants  have  invented  all  sorts 
of  clever  dodges  for  dispersing  their  seeds,  into 
the  nature  of  which  we  will  go  in  full  in  the 
sequel.  Thus,  some  of  them  put  feathery  tops 
to  their  seeds  or  fruits,  like  the  thistle  and  the 
dandelion,  the  willow  and  the  cotton-bush,  by 
means  of  which  they  float  lightly  on  the  air,  and 
are  wafted  by  the  wind  to  new  and  favourable 
situations.  Others,  again,  bribe  animals  to  dis- 
perse them,  by  the  allurement  of  sweet  and  pulpy 


INTRODUCTORY.  13 

fruits,  like  the  strawberry  or  the  orange ;  and  in 
all  these  instances,  though  the  fruit  or  outer  coat 
is  edible,  the  actual  seed  itself  is  hard  and  indi- 
gestible, like  the  orange -pip,  or  is  covered  with  a 
solid  envelope  like  the  cherry-stone.  Numerous 
other  examples  we  shall  see  by  and  by  in  their 
proper  place.  For  the  present,  we  have  only  to 
remember  that  plants  to  some  extent  provide 
beforehand  for  their  children,  and  in  many  cases 
take  care  to  set  them  out  in  life  to  the  best 
possible  advantage. 

Most  of  these  points  to  which  I  am  here 
briefly  calling  your  attention  are  true  only  of 
the  higher  plants,  and  especially  of  land-plants. 
For  we  must  not  forget  that  plants,  like  animals, 
differ  immensely  from  one  another  in  dignity, 
rank,  and  relative  development.  There  are 
higher  and  lower  orders.  We  shall  have  to 
consider,  therefore,  their  grades  and  classes — 
to  find  out  why  some  are  big,  some  small ;  some 
annual,  some  perennial ;  why  some  are  rooted  in 
dry  land,  while  some  float  freely  about  in  water ; 
why  some  have  soft  stems  like  spinach  and 
celery,  while  others  have  hard  trunks  like  the 
oak  and  the  chestnut.  We  shall  also  have  to 
ask  ourselves  what  were  the  causes  which  made 
them  differ  at  first  from  one  another,  and  to 
what  agencies  they  owe  the  various  steps  in 
their  upward  development.  In  short,  we  must 
not  rest  content  with  merely  saying  that  the 
rose  is  like  this  and  the  cabbage  like  that ;  we 
must  try  to  find  out  what  gave  to  each  of  them 
its  main  distinctive  features.  We  must  "  con- 
sider the  lilies,  how  they  grow,"  and  must  seek 


14        THE  STOEY  OF  THE  PLANTS. 

to  account  for  their  growth  and  their  peculiari- 
ties. 

And  now  let  me  sum  up  again  these  central 
ideas  of  our  future  reading  on  plants  and  their 
history. 

Plants  are  living  things ;  they  eat  with  their 
leaves,  and  drink  with  their  rootlets.  They  take 
up  carbon  from  the  air,  and  water  from  the  soil, 
and  build  the  materials  so  derived  into  their  own 
bodies.  Plants  also  marry  and  are  given  in 
marriage.  They  have  often  two  sexes,  male  and 
female.  Each  seed  is  thus  the  product  of  a 
separate  father  and  mother.  Plants  are  of  many 
kinds,  and  we  must  inquire  by  and  by  how  they 
came  to  be  so.  Plants  live  on  sea  and  land,  and 
have  varieties  specially  fitted  for  almost  every 
situation.  Plants  have  very  varied  ways  of 
securing  the  fertilisation  of  their  flowers,  and 
look  after  the  future  of  their  young,  like  good 
parents  tha*  they  are,  in  many  different  man- 
ners. Plants  are  higher  and  lower,  exactly  like 
animals. 

These  are  some  of  the  points  we  must  proceed 
to  consider  at  greater  length  in  the  following 
pages. 

CHAPTER    II. 

HOW    PLANTS    BEGAN    TO    BE. 

WHICH  came  first — the  plant  or  the  animal  ? 

That  question  is  almost  as  absurd  as  if  one 
were  to  ask,  Which  came  first — the  beast  of 
prey,  or  the  animals  it  preys  upon  ?  Clearly, 


HOW    PLANTS    BEGAN    TO    BE.  15 

the  earliest  animals  could  not  possibly  have  been 
lions  and  tigers;  for  lions  and  tigers  could  not 
begin  to  exist  till  after  there  were  deer  and 
antelopes  for  them  to  hunt  and  devour.  Now 
the  general  connection  between  animals  and 
plants  is  somewhat  the  same  in  this  respect  as 
the  general  connection  between  beasts  of  prey 
and  the  creatures  they  feed  upon.  For  all 
animals  feed,  directly  or  indirectly,  upon 
plants  and  their  products.  Even  carnivorous 
animals  eat  sheep  and  rabbits,  let  us  say ;  but 
then,  the  sheep  and  the  rabbits  eat  grass  and 
clover.  In  the  last  resort,  plants  are  self- 
supporting  ;  animals  feed  upon  what  the  plants 
have  laid  by  for  their  own  uses.  Every  animal 
gets  all  its  material  (except  water)  directly  or 
indirectly  from  plants.  In  one  word,  plants  are  . 
the  only  things  that  Jcnoiv  how  to  manufacture  j 
living  material.  ?  •"*'  y 

Eoughly  speaking,  plants  are  the  producers 
and  animals  the  consumers.  Plants  are  like 
the  pine-tree  that  makes  the  wood ;  animals  are 
like  the  fire  that  burns  it  up  and  reduces  it  to 
its  previous  unorganised  condition. 

It  is  a  little  difficult  really  to  understand  the 
true  relation  of  plants  and  animals  without 
some  small  mental  effort;  yet  the  point  is  so 
important,  and  will  help  us  so  much  in  our  after 
inquiries  that  I  will  venture  upon  asking  you  to 
make  that  effort,  here  at  the  very  outset. 

If  you  take  a  piece  of  wood  or  coal,  you  have 
in  it  a  quantity  of  hydrogen  and  carbon,  almost 
unmixed  with  oxygen,  or  at  least  combined  with 
far  less  oxygen  than  they  are  capable  of  uniting 


(t  d          •.tus&St""' 

16        THE  STOKY  OF  THE  PLANTS. 

with.  Now  put  a  light  to  the  wood  or  coal,  and 
what  happens  ?  They  catch  fire,  as  we  say,  and 
burn  till  they  are  consumed.  And  what  is  the 
meaning  of  this  burning  ?  Why,  the  carbon  and 
hydrogen  are  rushing  together  with  oxygen — 
taking  up  all  the  oxygen  they  can  unite  with, 
and  forming  with  it  carbonic  acid  and  water. 
The  carbon  joins  the  oxygen  in  a  very  close 
embrace,  and  becomes  carbonic  acid  gas,  which 
goes  up  the  chimney  and  mixes  with  the 
atmosphere ;  the  hydrogen  joins  the  oxygen  in 
an  equally  intimate  union,  and  similarly  goes  off 
into  the  air  in  the  form  of  steam  or  watery 
vapour.  Burning,  in  fact,  is  nothing  more  than 
the  union  of  the  carbon  and  hydrogen  in  wood  or 
coal  with  the  oxygen  of  the  atmosphere.  But 
observe  that,  as  the  carbon  and  hydrogen  burn, 
/  they  give  off  Alight  and  heat.  This  light  and 
Jf  ,  heat  they  held^ktored  up  before  in  their  separate 
'  \  form  ;  it  was,  so  to  speak,  dormant  or""*!&t!£ht 

{within  them.  Free  carbon  and  free  hydrogen 
contain  an  amount  of  energy,  that  is  to  say  of 
latent  lighted  fln^arji-.  h^,  which  they  yield 
tTjJ  wjiejX-they  unite  with  free  oxygen.  A*ncl 
thou^Iithe^carb(5r^jid  hydrogen  in  wood  and 
coal  are  not  quite  free,  they  may  be  regarded  as 
free  for  our  present  purpose. 

Now,  -sdifice  did  this  light  and  heat  come 
from?  Well,  the  wood,  we  know,  is  part  of  a 
tree  which  has  grown  in  the  open  air,  by  the  aid 
of  sunshine.  The  coal  is  just  equally  part  of 
certain  very  ancient  plants,  long  pressed  beneath 
the  earth  and  crushed  and  hardened,  but  still 
possessing  the  plant-like  property  of  burning 


iiOW  PLANTS  fcEGAH   TO   BE.  1? 

when  lighted.  In  both  cases  the  light  and  heatj 
as  we  shall  see  more  fully  hereafter,  are  derived 
from  the  sun,  our  great  storehouse  of  energy.  •' 
The  sunshine  fell  upon  the  leaves  of  the  nlodern 
oak-tree,  or  of  the  very  antique  club -mosses 
which  constitute  coal,  and  separated^in  them  the 
carbon  from  the  oxygen  oT  caT'bo^mc^acid ,  and 
trie*  hydrogen  from  the  oxygen  of  tfe^^ii^"  m  ,' 
the  sap?  In  each  case  the  oxygen  was  turned 
loose  upon  the  air  in  its  free  form,  while  the 
carbon  and  the  hydrogen  (with  a  very  little 
oxygen  and  a  few  other  materials)  were  lelTln 

in  the  leaves 


and  wood  of  the^oak  or  tEe  club-mos.s.  But  the 
point  to  which  I  wish  now  specially  to  direct 
your  attention  is  this — the  sunlight  was  actually 
used  up  for  the  time  being  in  effecting  this 
separation  between  the  oxygen  611  the  one  hand, 
and' the  carbon  and  hydrogen  on  the  other.  As 
long  as  the  plant  remained  unburnt,  the  light 
and  heat  it  received  from  the  sun  lay  dormant 
within  it,  not  as  actual  light  and  heat,  but  as 
ggl^yajiprL  between  the  oxygen  and  the  hydrogen 
or  carbon.  Coal,  indeed,  has  been  well  described 
as  "  bottled  sunshine." 

More  than  this ;  it  took  just  as  much  light  anal 
heat  from  the  sun  "to  builcf  lip  ltEe~pTaht  as  you* 
can  get  out  of  the  plant  in  the  end  by  bum-j 
ing  it. 

Now,  let  us  burn  .our  piece  of  wood  or  coal, 
and  what  happens  ?  Why,  particles  of  oxygen 
rush  together  with  particles  of  carbon  in  the 
fuel,  and  form  carbonic  acid.  How  much 
carbonic  acid  ?  Just  as  much  as  it  took 


18        THE  STOKY  OP  THE  PLANTS. 

oi4iginally  to  build  that  part  of  the  plant  from. 
Simultaneously,  other  particles  of  oxygen  in  the 
air  rush  together  with  particles  of  hydrogen  in 
the  fuel,  and  form  water,  in  the  shape  of  steam. 
How  much  water  ?  Just  as  much  as  it  took 
originally  to  build  thaT^paf¥~bT^the  plant  from. 
As  they  unite,  they  give  out  their  dormant  heat 
and  light.  How  much  heat  and  light  ?  Just  as 
rryicjj  as  they  absorbed  in  the  act  of  building  up 
those  parts  of  the  plant  from  the  sunshine  that 
fell  upon  them. 

/  In  other  words,  the  same  quantity  of  oxygen 
\that  was  first  separated  from  the  carbon  and 
/  hydrogen  reunites  with  them  in  the  act  of  burn- 
|  ing,  and  the  same  amount  of  heat  and  lights,  that 
(were  requIEecL'lib  effect' "ffieir  separation  is  yielded 
up  again  in  the  act  of  reunion. 

Let  us  put  this  point  numerically,  and  I  will 
simplify  it  exceedingly,  so  as  to  make  my 
meaning  clearer.  Suppose  we  -begin  with  a 
particle  of  carbonic  acid  and  a  particle  of  water 
in  the  interior  of  a  green  leaf — the  carbonic  acid 
swallowed  from  the  air  by  the  leaf,  the  water 
brought  to  it  as  sap  from  the  roots.  Now,  under 
the  influence  of  sunlight,  these  materials  are 
separated  into  their  component  parts.  The 
particle  of  carbonic  acid  consists  of  one  atom  of 
carbon,  closely  locked  up  with  two  "'atoms  of 
oxygen.  It  takes  an  amount  of  sunlight,  which 
we  will  call  A,  to  unlocKTffis  union,  and  separate 
the  atoms.  The  oxygen  goes  off  free  into  the 
air,  and  the  carbon  remains  in  the  leaf  as 
material  for  building  the  plant  up.  Again,  the 
particle  of  water  consists  of  two  atoms  of 


HOW  PLANTS  BEGAN  TO  BE.  19 

hydrogen,  closely  locked  up  with  one  atom  of 
oxygen.  If  iaJTes  aEraTn75unT of  sunlight,  which 
we  will  call  B,  to  unlock  this  union  and  separate 
the  atoms.  The  oxygen  once  more  goes^ofF'freir  ' 
into  the  air,  and  the  hydrogen  joins  in  a  loose  ^ 
union  with  the  carbon  already  spoken  of.  Islow, 
burn  the  material  resulting  from  these  two  acts, 
and  what  happens?  Two  atoms  of  oxygen 
once  more  unite  with  the  one  atom  of  carbon,  to 
form  a  particle  of  carbonic  acid ;  one  atom  of 
oxygen  once  more  unites  with  the  two  atoms  of 
hydrogen  £o  form  a  particle  of  water,  and  there 
is  given  out  injhe^act  of  union  an  amount  of 
light  and  heat  exacfly^ n  equal  'to_  the  A  and  B 
originally  locked^  up7m  tne  act  °f  separating 
them. 

I  have  now  made  it  clear,  I  hope,  what  plant 
life  really  is  in  its  final  essence.     In  nature  at 
large,  the  elements  which  chiefly  compose  it — 
namely,  carbon  and  hydrogen — exist  only  in  very 
close  union  with  oxygen  ;  the  plant  is  a  machineA 
for  separating  these  elements  Irom  oxygen  under  f 
the  influence  of  sunlight,  and  building  them  up 
into  fresh  forms,  whose  great  peculiarity  is  that  | 
they  possess  energy  or  dormant  motion.  } 

Now  the  animal  is  the  exact  opposite  of  all 
this.     He  is  essentially  a  destroyer,  as  the  plant 
is  a  builder.     The  plant  produces  ;  the  animal  1 
consumes  ;  the  plant  makes  living  matter,  the  A 
animal  breaks  it  down  again.     He  is,  in    fact,  / 
a  slowjire,  where  plant  products  like  grasses, 
fruits,  nuts,  or  grains,  are  consumed  by  degrees 
and  reduced  once  more  to  their  original  condition. 

The  animal  eats  what  the  plant  laid  by.     He 


20  THE   STOEY  OF  THE   PLANTS. 

also  breathes — that  is  to  say,  takes  oxygen  into 
his  lungs.  Within  his  body  that  oxygen  once 
more  unites  with  the  carbon  and  the  hydrogen, 
and  is  given  out  again  in  union  with  them  as 
carbonic  acid  and  water.  Andythe  energy  tin  the 
plant  food,  thus  set  free  within  hfs'  body,  takeg 
the  jorm  of^anirnal  hfeat  and  animal  motion— 
/jipF^a^TKeerlergy  seE  free  iii  tne  locomotive 
takes  the  form  oi  heat  and  visible  movement. 
Animals  are  thus  the  absolute  converse  of 
plants ;  all  that  the  plants  did,  the  animal 
undoes  again. 

Briefly  to  recapitulate  this  rather  dry  subject, 
— the  plant  is  a  mechanism  for  scparajing^oxygen 
from  carbon  and  iiy drogen ,  and  ior^storing  up 
sun-energy.  The  animal  is  a  mechanism  for 
uniting  oxygen  with  carbon  and  hydrogen,  and 
for  usinjr  the  stored-up  sun-energy  as  heat  and 
motton. 

And  now  you  can  see  why  it  is  so  absurd  to 

ask,  Which  came  first,  the  plant  or  the  animal  ? 

You  might  as  well  ask,  Which  came  first,  the 

coal  or  the  fire  ?     All  the  living  material  in  the 

world  was  first  macle    and   laid  up  by  plants. 

;  They  alone  have  fop,  pnwp.r  t,n  taak^  living  or- 

rncrgyj-yielding    stuff  out   of    deadancl    inert 

\  water   or   carbon!*1,  acid.     Thejfare   the  origin 

and  foundation   of    liie.     Without   them    there 

could  be  no   living  thing  in  the  universe.     It 

i  is  in  their  green  parts  alone  that  the  wonderful 

!  transformation  of  dead  matter  into  living  bodies 

^  takes  place  ;  they  alone  know  how  to  store  up 

and  utilise  the  sunshine  that  falls  upon  them. 


HOW   PLANTS   BEGAN   TO   BE.  21 

All  the  animal  can  do  is  to  take  the  living 
material  the  plant  has  made  for  him,  and  to 
consume  it  slowly  in  his  own  body.  He 
destroys  it  (as  living  matter)  just  as  truly  as  a 
fire  does,  and  turns  it  loose  on  the  air  again  in 
the  dead  and  inert  forms  of  water  and  carbonic 
acid. 

It  is  clear,  then,  that  plants  must  have  come 
first,  and  animals  afterward.  The  earliest  living 
beings  must  needs  have  been  plants — very 
simple  plants ;  yet  essentially  plants  in  this — 
that  they  were  green,  and  that  they  separated 
carbon  and  hydrogen  from  oxygen  under  tne 
influence  of  sunlight.  It  is  that  above  every  - 
thing  that  makes  true  plants ;  •  though^ some 
degenerate  plants  have  now  given  up  their 
ancestral  habit,  and  behave  in  this  respect  much 
like  animals. 

How  did  the  first  plant  of  all  come  into 
being  ? 

About  that,  at  present,  we  know  very  little. 
We  can  only  guess  that,  in  the  early  ages  of 
the  world,  when  matter  was  fresher  and  more 
plastic  than  now,  certain  combinations  were  set 
up  between  atoms  under  the  influence  of  sun- 
light, which  formed  the  earliest  living  body. 
This  would  be  what  is  called  "  spontaneous 
generation."  Whether  such  spontaneous  genera- 
tion ever  took  place  is  much  disputed ;  though 
some  people  competent  to  form  an  opinion 
incline  to  believe  that  it  probably  did  take  place 
in  remote  times  and  under  special  conditions. 
But  it  is  certain,  or  almost  certain,  that  in  our 


22        THE  STOKY  OF  THE  PLANTS. 

own  days  at  least  spontaneous  generation  does 

not  take  place — perhaps  because  all  the  available 

material  is  otherwise  employed,  perhaps  because 

the  conditions  are  no  longer  favourable.     At  any 

/rate,  we  have  every  reason  to  suppose  that  at  the 

'  present  day  every  living  being,  whether  plant  or 

\animal,  is  the  product  of  a  previous  living  being, 

its  parent,  or  of  two  previous  living  beings,  its 

father  and  mother. 

Why  should  this  be  so?  Well,  if  you  think 
for  a  moment,  you  will  see  that  it  results  almost 
naturally  from  the  other  facts  we  have  so  far 
considered.  For  the  plant  is  a  machine  for.  \ 
making  living  ma^tey  m\t  pf  water  anH  carbonic 
acI37~under  the  influence  of  sunlight.  As  long 
as  sunlight,  direct  or  reflected,  in  sun  or  shade, 
falls  upon  a  green  plant,  the  plant  goes  on 
taking  up  carbonic  acid  from  the  air  by  means 
of  its  leaves,  and  water  from  the  earth  by  means 
of  its  roots,  and  continues  to  manufacture  from 
them  |resh  living  material.  Thus  it  must  be 
always  groiving,  as  we  say ;  in  other  words,  the 
mass  of  living  material  must  be  constantly 
increasing.  Now,  it  results  from  this  that  the 
plant  would  grow  in  time  unwieldily  large  ;  and 
/in  simple  types,  when  it  grows  very  large,  it 
\  splits  or  divides  into  two  portions.  That  is  the 
real  origin  of  what  we  call  KEPKODUCTION.  In 
its  simplest  forms,  reproduction  means  no  more 
than  this — that  a  rather  large  body,  which  cannot 
easily  hold  together,  divides  in  two,  and  that 
each  part  of  it  then  continues  to  live  and  grow 
exactly  as  the  whole  did. 

This  seems  odd  and  unfamiliar  to  you,  because 


\ 


HOW   PLANTS    BEGAN   TO   BE.  23 

you  are  thinking  of  large  and  very  advanced 
plants,  like  a  sweet-pea  or  a  potato.  But  you 
must  remember  that  we  are  dealing  here  with 
very  early  and  simple  plants,  and  that  these 
early  and  simple  plants  consist  for  the  most  part 
of  tiny  greeT?  pij,tftsf  floating  free  in  water.  They 
are  generally  invisible  to  the  naked  eye,  and  are 
in  point  of  fact  mere  specks  of  green  jelly.  Yet 
it  is  from  such  insignificant  atoms  as  these  that 
the  great  forest  trees  derive  their  origin,  through 
a  long  line  of  ancestors ;  and  if  we  wish  to 
understand  the  larger  and  more  developed 
plants,  we  must  begin  by  understanding  these 
their  simple  relations. 

Very  early  plants,  then,  floated  free  in  water  ; 
and  there  is  reason  to  believe  that  for  a  con- 
siderable period  in  the  beginnings  of  our  world 
there  was  no  dry  land  at  all ;  the  whole  surface 
of  the  globe  was  covered  by  one  boundless  ocean. 
At  any  rate,  most  of  the  simplest  and  earliest 
forms  of  life  now  remaining  to  us  inhabit  the 
water,  either  fresh  or  salt ;  while  almost  all  the 
higher  and  nobler  plants  and  animals  are  dwellers 
on  land.  Hence  it  is  not  unreasonable  to  con- 
clude that  life  began  in  the  sea,  and  only 
gradually  spread  itself  over  the  islands  and 
continents. 

Floating  jelly-like  plants  would  readily  reach 
a  size  at  which  it  would  be  convenient  for  them 
to  split  in  two  —  or  rather,  at  which  it  would  be 
difficult  for  them  to  hold  together ;  and  most 

:very  small  floating  plants  do^to  this,  jj^Y  continue \ 
to  grow,  up  to  a  certain  point,  and  then  divide  '] 
into  two  similar  and  equal  portions.  This  is  the  | 


24        THE  STORY  OF  THE  PLANTS. 

simplest  known  form  of  what  we  call  reproduc- 
tion. Of  course,  the  two  halves  into  which  the 
plant  thus  divides  itself  are  exactly  like  one 
another ;  and  that  gives  us  the  basis  for  what 
i  we  call  HEREDITY — that  is  to  say,  the  general 
similarity  between  parent  and  offspring.  This 
similarity  depends  upon  the  fact  that  the  two 
were  once  ono,  and  when  they  split  or  divide 
each  part  continues  to  possess  all  the  qualities 
of  the  original  mass  of  which  it  once  formed  a 
portion. 

You  will  observe  that  I  here  use  the  words, 
parent  and  offspring.  I  do  so,  partly  from 
custom,  and  partly  to  show  where  this  reasoning 
leads  us.  But  in  reality,  in  such  very  simple 
plants,  neither  part  of  the  divided  whole  can 
claim  to  be  either  parent  or  child ;  they  are 
equal  and  similar.  In  higher  plants,  however 
(as  in  higher  animals),  we  find  that  the  main 
portion  of  the  plant  continues  to  live  and  grow, 
and  sends  off  smaller  portions,  known  as  spores 
or  seeds,  to  reproduce  its  species.  Here,  we 
may  fairly  speak  of  the  larger  plant  as  the 
parent,  and  of  the  smaller  ones  which  it  de- 
taches from  itself  as  its  children  or  offspring. 

The  truth  is,  every  gradation  exists  in  nature 
between  these  two  extreme  cases.  The  different 
types  glide  imperceptibly  into  one  another. 
There  is  no  one  point  at  which  we  can  definitely 
say,  "Here  reproduction  by  splitting  or  division 
ceases,  and  reproduction  by  eggs,  or  by  spores 
or  seeds  begins." 

Again,  all  the  earlier  and  simpler  plants  are 
sexless  ;  they  simply  grow  till  they  divide,  and 


HOW    PLANTS    BEGAN    TO    BE.  25 

then  the  two  halves  continue  to  exist  inde- 
pendently. No  two  distinct  plants  or  parts  of 
plants  are  concerned  in  producing  each  new 
individual.  But  the  higher  plants,  like  the 
higher  animals,  are  male  and  female.  In  such 
cases  two  distinct  individuals  combine  to  form 
a  new  one.  They  are  its  father  and  mother,  so 
to  speak,  and  the  young  one  is  their  offspring. 
A  little  grain  of  pollen  produced  by  the  male 
plant  unites  with  a  little  ovule  or  seedlet  pro- 
duced by  the  female  ;  and  from  the  union  of  the 
two  springs  a  fresh  young  plant,  deriving  its 
peculiarities  about  equally  from  each  of  them. 
How  and  why  this  great  change  in  the  mode 
of  reproduction  takes  place  is  another  of  the 
questions  we  must  discuss  hereafter ;  I  will 
only  anticipate  now  the  result  of  this  discussion 
by  saying  briefly  beforehand  that  plants  gain  in 
this  way,  because  greater  variety  is  secured  in 
the  offspring,  and  because  the  weak  points  of  9 
one  parent  are  likely  to  be  reinforced  and  made  * 
good  by  the  other. 

Let  us  sum  up  our  conclusions  in  this  pre- 
liminary chapter : — 

Plants  are  an  older  type  of  life  than  animals. 
They  are  the  first  and  mosif  original  form  of 
living  beings,  and  wjthrmt,  J^e.m,  yp  Jifa  nf^a.ny 
sort  would  be  possible.  All  living  matter  is 
manufactured  by  plants  out  of  material  found 
floating  in  the  air,  under  the  influence  of  sun- 
light. How  plants  first  came  into  existence  we 
do  not  yet  know  ;  but  we  may  suspect  that  they 
grew,  in  very  simple  and  small  forms,  at  & 


26        THE  STORY  OF  THE  PLANTS. 

remote  period,  under  conditions  which  now  no 
longer  exist.  It  is  almost  certain  that  the  first 
plants  were  jelly-like  specks,  floating  freely  in 
water.  They  must  have  been  green,  and  must 
also  have  possessed  the  essential  plant-power  of 
building  up  fresh  living  material  when  sunlight 
fell  upon  them.  This  power  implies  the  other 
power  of  reproduction,  that  is  to  say  of  splitting 
up  into  two  or  more  similar  parts,  each  of  which 
continues  to  live  and  grow  like  the  original  body. 
From  such  simple  and  very  primordial  plants 
all  other  and  higher  forms  are  most  likely 
descended. 

CHAPTEE  III. 

HOW  PLANTS  CAME  TO  DIFFER  FKOM  ONE  ANOTHER. 

ALL  plants  are  not  now  alike.  Some  are  trees, 
some  herbs ;  some  are  roses,  some  buttercups. 
Yet  we  have  a  certain  amount  of  reason  to 
believe  that  they  are  all  descended  from  one  and 
the  same  original  ancestor ;  and  we  shall  see  by 
and  by  that  we  can  often  trace  the  various 
stages  in  their  long  development.  They  differ 
immensely.  Some  of  them  are  more  advanced 
and  more  complex  than  their  neighbours  ;  some 
are  small  and  low,  while  others  are  tall  and 
strong;  some,  like  nettles  and  grasses,  have 
simple  and  inconspicuous  flowers,  while  others, 
like  lilies  and  orchids,  have  beautiful  and  very 
complicated  blossoms,  highly  arranged  in  such 
ways  as  to  attract  and  entice  particular  insects 
to  visit  and  fertilise  them.  Again,  some  havq 


HOW   PLANTS    CAME    TO    DIFFEE.  27 

tiny  dry  fruits,  with  small  round  seeds,  which 
fall  on  the  ground  unheeded ;  while  others  have 
brilliant  red  or  yellow  berries,  or  winged  or 
feathery  seeds,  especially  fitted  for  special  modes 
of  dispersion.  In  short,  there  are  plants  which 
seem,  as  it  were,  very  low  and  uncivilised,  while 
there  are  others  which  display,  so  to  speak,  all 
the  latest  modern  inventions  and  improvements. 

The  question  is,  How  did  they  thus  come  to 
differ  from  one  another  ?  What  made  them 
vary  in  such  diverse  ways  from  the  primitive 
pattern  ? 

In  order  to  understand  the  answer  which 
modern  science  gives  to  this  question,  we  must 
first  glance  briefly  at  certain  early  steps  in  the 
history  of  the  process  which  we  call  creation  or 
evolution. 

The  earliest  plants,  we  saw,  were  in  all  pro- 
bability mere  tiny  green  jelly- specks,  floating 
free  in  water,  and  taking  from  it  small  quantities 
of  dissolved  carbonic  acid,  which  they  manu- 
factured for  themselves  into  green  living  material 
when  sunlight  fell  upon  them.  Now  we  shall 
have  to  consider  another  peculiarity  of  plants 
(and  of  animals  as  well)  before  we  can 
thoroughly  understand  the  first  stage  in  the 
upward  process  which  leads  at  last  to  the  pine 
and  the  lily,  the  palm  and  the  apple. 

Plants  are  made  up  of  separate  parts  or 
elements,  known  as  cells,  each  of  which  consists 
of  a  thin  cell- wall,  usually  containing  living 
material.  The  very  simplest  and  earliest  plants, 
however,  consist  of  a  single  such  cell  apiece ; 


28        THE  STORY  OF  THE  PLANTS. 

they  are  specks  of  green  jelly,  enclosed  by  a 
cell-wall,  alone  and  isolated.  In  such  cases, 
when  the  cell  grows  big  and  divides  in  two,  each 
half  floats  off  as  a  separate  cell,  or  a  separate 
plant,  and  continues  to  divide  again  and  again, 
as  long  as  it  can  get  a  sufficient  amount  of 
carbonic  acid  and  sunlight.  But  in  some 
instances  it  happens  that  the  new  cells,  when 
budded  out  from  the  old  ones,  do  not  float  off 
in  water,  but  remain  hanging  together  in  long 
strings  or  threads,  in  single  file,  as  you  may  see 
in  certain  simple  forms  of  hair-like  pond- weeds. 
These  weeds  consist  of  rows  of  cells,  stuck  one 
after  another,  not  unlike  rows  of  pearls  in  a 
necklace.  Of  course  the  individual  cells  are  too 
small  to  see  with  one's  unaided  eye ;  but  under 
a  microscope  you  can  see  them,  joined  end  to 
end,  so  as  to  form  a  sort  of  thread  or  long  line 
of  plant-cells.  This  is  the  beginning  of  the 
formation  of  the  higher  plants,  which  consist, 
I  indeed,  of  collections  of  cells,  arranged  either 
I  in  rows  or  in  flattened  blades,  or  many  deep 
|  together  in  complicated  order. 

However,  the  higher  plants  differ  from  the 
lower  ones  in  something  more  than  the  number 
and  complexity  of  the  cells  which  compose  them. 
They  are  very  varied ;  and  their  variety  adapts 
them  to  their  special  circumstances.  For 
example,  desert  plants,  like  the  cactuses,  have 
thick  and  fleshy  leaves  (or,  rather,  jointed  stems) 
to  store  up  water,  with  a  very  tough  skin  to 
prevent  evaporation.  The  flowers  of  each 
country,  again,  are  exactly  adapted  to  the 
insects  of  that  country;  and  so  are  the  fruits 


ItOW  PkANtfS   CAME   TO   DlFFEli.  29 


to  the  birds  that  swallow  and  disperse  them. 
How  did  this  all  come  about  ?     What  made  the 
adaptation  ?     It  is  a  result  of  two  great  under-  ) 
lying  principles  known  as  The  Struggle  for  Life,\ 
and  Natural  Selection. 

Since  each  early  plant  goes  on  growing  and 
dividing,  again  and  again,  as  fast  as  it  can,  it 
must  follow  in  time  that  a  great  number  of 
plants  will  soon  be  produced,  each  righting  with 
the  others  for  air  and  sunlight.  Now,  some  of 
them  must,  by  pure  accident  of  situation,  get 
better  placed  than  others  ;  and  these  will  pro- 
duce greater  numbers  of  descendants.  Again, 
unless  all  of  them  remained  utterly  uninfluenced 
by  circumstances  (which  is  not  likely)  it  must 
necessarily  happen  that  slight  differences  will 
come  to  exist  between  them.  These  differences 
of  outline,  or  shape,  or  cell-  wall,  may  happen  to 
make  it  easier  or  harder  for  the  plant  to  get 
access  to  carbonic  acid  and  sunlight,  or  to 
disperse  its  young,  or  to  fix  itself  favourably. 
Those  plants,  therefore,  which  happened  to  vary 
in  the  right  directions  would  most  easily  go  on 
living  and  produce  most  descendants,  whilA\ 
those  which  happened  to  vary  in  the  wrong 
directions  would  soonest  die  out  and  leave 
fewest  descendants. 

Well,  the  world  around  us,  both  of  plants  and 
animals,  is  full  of  creatures  all  struggling  against 
one  another,  and  all  competing  for  food  and  air? 
and  sunshine.     Moreover,  each  individual  pro-* 
duces  (as  a  rule)  a  'vast  number  of  young  ;  some- 
times, like  the  poppy,  many  thousand  seeds  on 
a  single  flower-stem.     Now  suppose  only  ten  of 


'60  THE    STOKY  OF   THE   PLANTS. 

those  seeds  succeed  in  growing  each  year.  In 
the  first  year,  that  poppy  will  have  produced  ten 
new  poppy  plants ;  the  year  after,  each  of  those 
ten  will  have  produced  ten  more,  making  the 
total  100 ;  in  the  third  year,  they  will  be  1,000 ; 
in  the  fourth,  10,000 ;  and  so  on  in  the  same 
progression  till  in  a  very  few  years  the  whole 
world  would  simply  be  full  of  poppies.  And 
similarly  with  animals.  If  every  egg  in  a  cod's 
roe  developed  into  a  mature  fish,  the  sea  would 
soon  be  one  solid  and  compact  mass  of  cod-fish. 

Why  doesn't  this  happen  ?  Because  every 
other  kind  is  producing  seeds  or  eggs  at  about 
the  same  rate,  and  every  one  of  them  is  fighting 
against  the  other  for  its  share  of  light  and  food 
and  soil  and  water.  The  stronger  or  better- 
adapted  survive,  while  the  weaker  or  less- 
adapted  go  to  the  wall,  and  are  starved  out  of 
existence.  At  first,  to  be  sure,  it  sounds  odd 
to  talk  of  a  Struggle  for  Life  among  plants,  which 
seem  too  fixed  and  inert  to  battle  against  one 
another.  But  they  do  battle  for  all  that.  Each 
root  is  striving  with  all  its  might  to  fix  itself 
underground  in  the  best  position ;  each  leaf  and 
stem  is  struggling  hard  to  overtop  its  neighbour, 
and  secure  its  fair  share  of  carbon  and  of  sun- 
shine. When  a  garden  is  abandoned,  you  can 
very  soon  see  the  result  of  this  struggle  ;  for  the 
flowers,  which  we  only  keep  alive  by  weeding — 
that  is  to  say,  by  uprooting  the  sturdier  com- 
petitors— are  soon  overgrown  and  killed  out  by 
the  weeds — that  is  to  say,  by  the  stronger  and 
better-adapted  native  plants  of  the  district. 

This,  then,  is  the  nature  and  meaning  of  these 


HOW   PLANTS    CAME    TO   DIFFEK.  31 

two  great  principles.  The  Struggle  for  Life 
means  that  more  creatures  are  produced  than 
there  is  room  in  the  world  for.  Natural  Selec- 
tion (or  Survival  of  the  Fittest)  means  that  among 
them  all,  those  which  happen  to  be  best  adapted 
to  their  particular  circumstances  oftenest  suc- 
ceed and  leave  most  offspring. 

By  the  action  of  the  two  great  principles  in 
question  (which  affect  all  life,  animal  or  vege- 
table) the  world  has  been  gradually  filled  with 
an  immense  variety  of  wonderful  and  beautiful 
creatures,  all  ultimately  descended  (as  modern 
thinkers  hold)  from  the  selfsame  ancestors. 
The  simple  little  green  jelly-speck,  which  is  the 
primitive  plant,  has  given  rise "  in  time  to  the 
sea- weeds  and  liverworts,  then  to  the  mosses 
and  ferns,  then  to  the  simplest  flowering  plants, 
thence  to  the  shrubs  and  trees,  and  finally  to 
all  the  immense  wealth  and  variety  of  fruits, 
flowers,  and  foliage  we  now  see  around  us. 

The  rest  of  this  book  will  consist  mainly  of  an 
exposition  of  the  results  brought  about  among 
plants  by  Variation,  the  Struggle  for  Life,  and 
Survival  of  the  Fittest.  But  before  we  go  on  to 
examine  them  in  detail,  I  shall  give  just  a  few 
characteristic  instances  which  show  the  mode  of 
action  of  these  important  principles. 

There  is  a  pretty  wild  flower  in  our  hedges 
called  a  red  campion,  or  "  Eobin  Hood/'  Now, 
a  single  red  campion  produces  in  a  year  three 
thousand  seeds.  But  there  are  not  three  thou- 
sand times  as  many  red  campions  this  year  as 
last,  nor  will  there  be  three  thousand  times  as 


32        THE  STORY  OF  THE  PLANTS* 

many  more  again  next  season.  Indeed,  if  an 
annual  plant  had  only  two  seeds,  each  of  which 
lived  and  produced  two  more,  and  so  on  con- 
tinually, in  twenty  years  its  descendants  would 
amount  to  no  less  than  a  million.  From  all  this 
it  necessarily  results  that  a  Struggle  for  Exis- 
tence must  take  place  among  plants ;  they  fight 
with  one  another  for  the  soil,  the  rain,  the 
carbon,  the  sunshine. 

Again,  take  such  a  wild  flower  as  this  very  red 
campion.  Why  has  it  light  pink  petals?  The 
reason  is,  to  attract  the  insects  which  fertilise 
it.  Flowers,  in  which  the  pollen  is  carried  by 
the  wind,  never  have  brilliant  or  conspicuous 
blossoms ;  but  flowers  which  are  fertilised  by 
insects  have  almost  always  coloured  petals  to  tell 
the  insects  where  to  find  the  honey.  How  did 
this  come  about?  In  this  way,  I  imagine  :  Many 
plants  produce  a  sweet  juice  on  their  leaves — for 
example,  the  common  laurel.  This  juice,  which 
is  probably  of  no  particular  use  to  them,  is  very 
greedily  eaten  by  insects.  Now  suppose  some 
flower,  by  accident  at  first,  happened  to  produce 
such  sweet  juice  near  its  stamens,  which  (as  we 
saw)  are  the  organs  for  making  pollen,  and  also 
near  its  pistil,  which  contains  its  young  seeds  or 
ovules.  Then  insects  would  naturally  visit  it  to 
eat  this  sweet  juice,  which  we  commonly  call 
honey.  In  eating  it,  they  would  dust  themselves 
over  with  the  floury  pollen,  by  pure  accident,  and 
they  would  carry  som,e  of  it  away  with  them  on 
their  heads  and  legs  to  the  next  flower  they 
visited.  Chance  would  make  them  often  rub  off 
the  pollen  and  fertilise  the  flower ;  and  as  such 


HOW  PLANTS  CAME   TO   tUFFEft.  33 

cross-fertilisation,  as  it  is  called,  is  good'  for  the 
plants,  producing  very  strong  and  vigorous 
seedlings,  the  young  ones  so  set  would  have 
the  best  chance  of  flourishing  and  surviving  in 
the  Struggle  for  Existence.  Thus  the  flowers 
which  made  most  honey  would  be  oftenest 
visited  and  crossed,  so  that  they  would  soon 
become  very  numerous.  Again,  if  they  hap- 
pened to  have  bright  leaves  near  the  honey, 
they  would  be  most  readily  discriminated,  and 
oftenest  visited.  So,  in  the  long  run,  it  has 
come  about  that  almost  all  the  flowers  fertilised 
by  insects  produce  honey  to  allure  them,  and 
have  brilliant  petals  to  guide  their  allies  to  the 
honey.  That,  in  fact,  is  what  beautiful  flowers 
are  for  —  to  attract  the  fertilising  bees  and 
butterflies  to  visit  and  impregnate  the  various 
blossoms. 

Take  one  more  case — or,  rather,  the  same 
case,  extended  a  little  further.  The  red  cam- 
pion flowers  by  day,  and  is  fertilised  by  butter- 
flies; therefore  it  is  pink,  because  pink  is  an 
attractive  colour  in  the  daylight ;  and  it  is  scent- 
less, because  its  colour  alone  is  quite  enough  to 
attract  sufficient  insects.  But  it  has  a  close 
relation,  the  white  campion,  which  flowers  by 
night  only,  and  lays  itself  out  to  be  visited  by 
moths  in  the  twilight.  Why  is  this  kind  white  ? 
Because  no  other  colour  is  seen  so  well  in  the 
dusk ;  a  red  or  pink  blossom  would  then  be 
almost  invisible.  Moreover,  the  white  cam- 
pion is  heavily  scented,  as  are  almost  all  other 
night-flowering  blossoms,  like  the  jasmine,  the 
tuberose,  the  stephanotis,  and  the  gardenia. 
3 


34        THE  STOEY  OF  THE  PLANTS. 

Observe  the  numerous  points  of  similarity  :  all 
these  are  white ;  all  are  sweet-scented ;  all  are 
moth-fertilised.  Why  is  this?  Because  the 
scent  helps  to  show  the  moth  the  way  to  the 
flower  when  there  is  hardly  enough  light  for  him 
to  see  the  white  petals.  Thus  every  plant  is 
adapted  to  its  particular  station  in  life,  and  its 
adaptation  is  the  result  of  the  Struggle  for 
Existence,  and  Survival  of  the  Fittest. 

Briefly  put,  whatever  variation  helps  the  plant 
in  any  way  in  any  particular  place,  or  at  any 
particular  time,  is  likely  to  give  it  an  extra 
chance  in  the  fight,  and  is  therefore  reproduced 
in  all  its  descendants. 

So  that  is  how  plants  began  to  vary. 

To  sum  up.  Plants  grow,  because  they  keep 
on  continually  taking  in  carbon  and  hydrogen 
from  the  world  outside  them,  under  the  in- 
fluence of  sunlight.  They  multiply,  because 
when  they  have  attained  a  certain  size  they 
split  up  to  form  two  or  more  individuals.  They 
struggle  for  life  with  one  another,  because  more 
are  produced  than  can  find  means  of  livelihood. 
And  the  struggle  results  in  Survival  of  the  Fittest. 

Or,  looked  at  in  another  light.  Plants 
multiply,  and  as  they  multiply  by  division  the 
new  ones  on  the  whole  resemble  their  parents  ; 

Jthis  is  the  law  of  PifftfflJT-fy  But  they  do  not 
exactly  resemble  them  in  every  detail ;  this  is 
the  law  of  Variation.  And  as  some  variations 
are  to  the  good7and  some  to  the  bad,  the  better 
survive  and  produce  young  like  themselves 
oftener  than  the  worse  do ;  this  is  the  law  of 
Natural  Selection. 


CHAPTEK  IV. 

HOW    PLANTS   EAT. 

WE  saw  in  the  last  chapter  how  and  why  plants 
came  to  differ  from  one  another,  but  not  why 
they  came  to  be  divided  into  well-marked  groups 
or  kinds,  such  as  primroses,  daisies,  cabbages, 
oaks,  and  willows.  In  the  world  around  us  we 
observe  a  great  many  different  sorts  of  plants, 
not  all  mixed  up  together,  so  to  speak,  nor 
merging  into  one  another  by  endless  gradations, 
but  often  clearly  marked  off  by  definite  lines  into 
groups  or  families.  Thus  a  primrose  is  quite 
distinct  from  a  crocus,  and  an  oak  from  a  maple. 
For  the  present,  however,  I  do  not  propose  to  go 
into  the  question  of  how  they  came  to  be  divided 
into  such  natural  groups.  I  will  begin  by  telling 
you  briefly  how  plants  eat  and  drink,  marry  and 
rear  families,  and  then  will  return  later  on  to 
this  problem  of  the  Origin  of  Species,  as  it  is 
called,  and  the  pedigrees  and  relationships  of  the 
leading  plant  families. 

First  of  all,  then,  we  will  inquire,  How  Plants 
Eat.  And  in  this  inquiry  I  will  neglect  for  the 
most  part  the  very  early  and  simple  plants  we 
have  already  spoken  about,  and  will  chiefly 
deal  with  those  more  advanced  and  complicated 
types,  the  flowering  plants,  with  which  every- 
body is  familiar. 

Plants  Eat  with  their  Leaves.  The  leaves  are, 
in  fact,  their  mouths  and  stomachs. 


36  THE  STOHY  OF  THE 

Now,  what  is  a  leaf  ?  It  is  usually  a  rather 
thin,  flat  body,  often  with  two  parts,  a  stalk  and 
a  blade,  as  in  the  oak  or  the  beech ;  though 
sometimes  the  stalk  is  suppressed,  as  in  grass 
and  the  teasel.  Almost  always,  however,  the 
leaf  is  green :  it  is  broad  and  flat,  with  a  large 
expanded  surface,  and  this  surface  is  spread  out 
horizontally,  so  as  to  catch  as  much  as  possible 
of  the  sunlight  that  falls  upon  it.  Its  business  is 
to  swallow  carbonic  acid  from  the  air,  and  digest 
and  assimilate  it  under  the  influence  of  sunlight. 
And  as  different  situations  require  different 
treatment,  various  plants  have  leaves  of  very 
different  shapes,  each  adapted  to  the  habits  and 
manners  of  the  particular  kind  that  produces 
them.  The  difference  has  been  brought  about 
by  Natural  Selection. 

What  does  the  leaf  eat  ?  Carbonic  acid. 
There  is  a  small  quantity  of  this  gas  always 
floating  about  dispersed  in  the  air,  and  plants 
fight  with  one  another  to  get  as  much  as  possible 
of  it.  Most  people  imagine  plants  grow  out  of 
the  soil.  This  is  quite  a  mistake.  The  portion 
of  its  solid  material  which  a  plant  gets  out  of 
the  soil  (though  absolutely  necessary  to  it)  is 
hardly  worth  taking  into  consideration,  nume- 
rically speaking ;  by  far  the  larger  part  of  its 
substance  comes  directly  out  of  the  air  as 
carbon,  or  out  of  the  water  as  hydrogen  and 
oxygen.  You  can  easily  see  that  this  is  so  if 
you  dry  a  small  bush  thoroughly,  leaves  and 
all,  and  then  burn  it.  What  becomes  of  it 
in  such  circumstances  ?  You  will  find  that 
the  greater  part  of  it  disappears,  or  goes  off 


HOW   PLANTS    EAT.  37 

into  the  atmosphere ;  the  carbon,  uniting  with 
oxygen,  goes  off  in  the  form  of  carbonic  acid, 
while  the  hydrogen,  uniting  with  oxygen,  goes  off 
in  the  form  of  steam  or  vapour  of  water.  What 
is  there  left  ?  A  very  small  quantity  of  solid 
matter,  which  we  know  as  ash.  Well,  that  ash, 
which  returns  to  the  soil  in  the  solid  condition, 
is  practically  almost  the  only  part  the  plant  got 
from  the  soil ;  the  rest  returns  as  gas  and  vapour 
to  the  air  and  water,  from  which  the  plant  took 
them.  You  must  never  forget  this  most  im- 
portant fact,  that  plants  grow  mainly  from  air 
and  water,  and  hardly  at  all  from  the  soil  beneath 
them.  Unless  you  keep  it  firmly  in  mind, 
you  will  not  understand  a  great  deal  that 
follows. 

Why,  then,  do  gardeners  and  farmers  think  so 
much  about  the  soil  and  so  little  about  the  air, 
which  is  the  chief  source  of  all  living  material  ? 
We  shall  answer  that  question  in  the  next 
chapter,  when  we  come  to  consider  What  Plants 
Drink,  and  what  food  they  take  up  dissolved  in 
their  water. 

Carbonic  acid,  though  itself  a  gas,  is  the  chief 
source  of  the  solid  material  of  plants.  How  do 
plants  eat  it  ?  By  means  of  the  green  leaves, 
which  suck  in  floating  particles  of  the  gaseous 
food.  Their  eating  is  thus  more  like  breathing 
than  ours  :  nevertheless,  it  is  true  feeding  :  it  is 
their  way  of  taking  in  fresh  material  for  building 
up  their  bodies.  If  you  examine  a  thin  slice 
from  a  leaf  under  the  microscope,  you  will  find 
that  its  upper  surface  consists  of  a  layer  of  cells 


38        THE  STORY  OF  THE  PLANTS. 

with  transparent  walls,  and  no  colouring  matter 
(Fig.  1).  These  cells  are  full  of  water ;  they 
form  a  sort  of  water-cushion  on  the  top  of  the 
leaf,  which  drinks  in  carbonic  acid  (or,  to  be 
quite  correct,  its  floating  form,  carbon  dioxide) 
from  the  air  about  it.  Immediately  below  this 
cushion  of  water-cells  you  come  again  upon  a 


"oocooqqqqaqq 


FIG.    1. — A  THIN    SLICE    FBOM   A  LEAF,    SEEN   UNDER 

THE  MICROSCOPE.  On  top  are  water-cells,  which 
suck  in  carbonic  acid.  Beneath  these  are 
green  cells,  which  assimilate  it  under  the 
influence  of  sunlight.  The  spongy  lower 
portion  is  used  for  evaporation. 

firm  layer  of  closely-packed  green  cells,  filled  with 
living  green- stuff,  which  take  the  carbonic  acid 
in  turn  from  the  water-cells,  and  manufacture 
it  forthwith  into  sugars,  starches,  and  other 
materials  of  living  bodies.  The  lowest  spongy 
part  evaporates  unnecessary  water,  and  so  helps 
to  keep  U£_cirgulation, 


HOW   PLANTS   EAT.  39 

The  plant  has  often  many  hundred  leaves,  that 
is  to  say,  many  hundred  mouths  and  stomachs. 
Why  do  plants  need  so  many  when  we  have  but 
one?  Because  they  cannot  move,  and  because 
their  food  is  a  gas,  diffused  in  minute  quantities 
through  all  the  atmosphere.  They  have  to  suck 
it  in  wherever  they  can  find  it.  And  what  do 
they  do  with  the  carbonic  acid  when  once  they 
have  got  it?  Well,  to  answer  that  question, 
I  must  tell  you  a  little  more  about  what  the 
ordinary  green  leaf  is  made  of,  and  especially 
about  the  green-stuff  in  its  central  cells. 

Now  what  is  this  green-stuff?  It  is  the  true* 
life-material  of  the  plant,  the  origin  of  all  the 
ImngTna/Eter  in  nature.  You  and  I,  as  well  as  the 
plants  themselves,  are  entirely  built  up  of  living  ?' 
jelly  which  this  green-stuff  has  manufactured 
under  the  influence  of  sunlight.  And  the  mate- 
rial that  does  this  is  such  an  important  thing  in 
the  history  of  life  that  I  will  venture  to  trouble 
you  with  its  scientific  name,  CHLOROPHYLL. 
When  sunlight  falls  upon  the  Chlorophyll  ^>r 
green-stuff  in  a  living  leaf,  in  the  presence  of 
carbonic  acid  and  water,  the  chlorophyll  at  once 
proceeds  to  set  free  the  oxygen  (which  it  turns 
loose  upon  trie  air  again),  and  to  build  up  the 
carbon  and  hydrogen  (with  a  little  oxygen)  into 
a  material  called  starch.  This  starch,  as  you 
know,  possesses  jwergy — that  is  to  say,  latent 
light  and  dormant'  1TB9F"  and  rribvement,  because 
we  can  eat  it  and  burn  it  within  our  bodies. . 
Other  materials,  hydro-carbons  and  carbo-hy- 
drates, as  they  are  called,  are  made  in  the  same 
way.  The  main  use  of  leaves,  then,  is  to  eat 


40        THE  STORY  OF  THE  PLANTS. 

carbon  and  drink  water,  and,  under  the  influ- 
ence of  sunlight,  to  take  in  energy  and  build 
them  up  into  living  material.1*" 

The  starch  and  sugar  and  other  things  thus 
made  are  afterwards  dissolved  in  the  sap,  and 
used  by  the  plant  to  manufacture  new  cells  and 
leaves,  or  to  combine  with  other  important  mate- 
rials of  which  I  shall  speak  hereafter,  in  order 
to  form  fresh  living  chlorophyll. 

Now  we  know  what  leaves  are  for ;  and  you 
can  easily  see,  therefore,  that  they  are  by  far  the 
most  essential  and  important  part  of  the  entire 
plant.  Most  plants,  in  fact,  consist  of  little  else 
than  colonies  of  leaves,  together  with  the  flowers 
which  are  their  reproductive  organs.  We  have 
next  to  see  Wliat  Shapes  various  Leaves  assume, 
and  what  are  their  reasons  for  doing  so. 

The  leaf  has,  as  a  rule,  to  be  broad  and  flat, 
in  order  to  catch  as  much  carbon  as  possible ;  it 
has  also  usually  to  be  expanded  horizontally  to 
the  sunlight,  so  as  to  catch  and  fix  it.  For  this 
reason,  most  leaves  that  can  raise  themselves 
freely  to  the  sun  and  air  are  flat  and  horizontal. 
But  in  very  crowded  and  overgrown  spots,  like 
thickets  and  hedgerows,  the  leaves  have  to  fight 
hard  with  one  another  for  air  and  sunlight ;  and 
in  such  places  particular  kinds  of  plants  have 
been  developed,  with  leaves  of  special  forms 
adapted  to  the  situation.  The  fittest  have 
survived,  and  have  assumed  such  shapes  as 
natural  selection  dictated. 

Where  the  plants  are  large  and  grow  freely 
upward,  with  plenty  of  room,  the  leaves  are 


HOW   PLANTS   EAT.  41 

usually  broad  and  expanded,  as  in  the  tobacco- 
plant  and  the  sunflower.  Where  the  plants 
grow  thick  and  close  in  meadows,  the  leaves 
are  mostly  long  and  narrow,  like  grasses.  In 
overgrown  clumps  and  hedgerows  they  are 
generally  much  subdivided  into  numerous  little 
leaflets,  as  is  the  case  with  most  ferns,  and  also 
with  herb-Eobert,  chervil,  milfoil,  and  vetches. 
In  these  last  cases,  the  plant  wants  to  get  as 
much  of  the  floating  carbonic  acid,  and  of  the 
sunlight,  as  it  can ;  and  therefore  it  makes  its 
leaves  into  a  sort  of  divided  network,  so  as  to 
entrap  the  smallest  passing  atom  of  carbon,  and 
to  intercept  such  stray  rays  of  broken  sunlight 
as  have  not  been  caught  by  the  taller  plants 
above  it.  In  almost  all  cases,  too,  the  leaves 
on  the  same  plant  are  so  arranged  round  the 
stem  and  on  the  branches  as  to  interfere  with 
one  another  as  little  as  possible ;  they  are  placed 
in  an  order  which  allows  the  sunshine  to  reach 
every  leaf,  and  which  secures  a  free  passage  of 
air  between  them. 

An  interesting  example  of  the  way  some  of 
these  principles  work  out  in  practice  is  afforded 
us  by  a  common  little  English  pond-weed,  the 
water-crowfoot.  This  curious  plant  grows  in 
streams  and  lakes,  and  has  two  quite  different 
types  of  leaves,  one  floating,  and  one  submerged. 
The  floating  leaves  have  plenty  of  room  to  develop 
themselves  freely  on  the  surface  of  the  pond; 
they  loll  on  the  top,  well  supported  by  the  mass 
of  water  beneath ;  and,  as  there  is  little  compe- 
tition, they  can  get  an  almost  unlimited  supply 
of  carbonic  acid  and  sunshine,  Therefore,  they 


42        THE  STORY  OF  THE  PLANTS. 

are  large  and  roundish,  like  a  very  full  ivy-leaf. 
But  the  submerged  leaves  wave  up  and  down  in 
the  water  below,  and  have  to  catch  what  little 
dissolved  carbonic  acid  they  can  find  in  the  pond 
around  them.  Therefore  they  are  dissected  into 
endless  hair-like  ends,  which  move  freely  about 
in  the  moving  water  in  search  of  food- stuff.  The 
two  types  may  be  aptly  compared  to  lungs  and 
gills,  only  in  the  one  case  it  is  carbonic  acid  and 
in  the  other  case  oxygen,  that  the  highly-dissected 
organs  are  seeking  in  the  water. 

As  a  general  rule,  when  a  plant  can  spread  its 
leaves  freely  about  through  unoccupied  air,  with 
plenty  of  sunlight,  it  makes  them  circular,  or 
nearly  so,  and  supports  them  by  means  of  a  stem 
in  the  middle.  This  is  particularly  the  case  with 
floating  river-plants,  such  as  the  water-lily  and 
the  water-gentian.  But  even  terrestrial  plants, 
when  they  can  raise  their  foliage  easily  into 
unoccupied  space,  free  from  competition,  have 
similar  round  leaves,  supported  by  a  central 
leaf-stalk,  as  is  the  case  with  the  familiar  garden 
annual  popularly  (though  erroneously)  known  as 
nasturtium.  (Its  real  name  is  Tropaeplum.)  On 
the  other  hand,  when  a  plant  has^o  struggle 
hard  for  carbon  and  sunlight  in  overgrown 
thickets,  or  under  the  water,  it  has  usually  very 
much  subdivided  leaves,  minutely  cut,  again  and 
again,  into  endless  segments.  Submerged  leaves 
invariably  display  this  tendency. 

But  that  does  not  conclude  the  whole  set  of 
circumstances  which  govern  the  forms  and  size 
of  leaves,  Not  only  do  they  want  to  eat,  and  to 


HOW   PLANTS   EAT.  43 

have  access  to  sunshine ;  they  must  also  be  sup- 
ported or  held  in  place  so  as  to  catch  it.  For 
this  purpose  they  have  need  of  what  we  may 
venture  to  describe  as  foliar  architecture.  This 
architecture  takes  the  form  of  ribs  or  beams  of 
harder  material,  which  ramify  through  and  raise 
aloft  the  softer  and  actively  living  cell-stuff. 
They  are,  as  it  were,  the  skeleton  or  framework 
of  the  leaf ;  and  in  what  are  commonly  known 
as  "  skeleton  leaves  "  the  living  cell-stuff  between 
has  been  rotted  away,  so  as  to  display  this  harder 
underlying  skeleton  or  framework.  It  is  com- 
posed of  specially  hardened,  lengthened,  and 
strengthened  cells,  and  is  intended,  not  only  to 
do  certain  living  work  in  the  plant  (as  we  shall 
see  hereafter),  but  also  to  form  a  supporting 
scaffolding.  The  material  of  which  ribs  or 
beams  are  composed  is  called  "  vascular  tissue  " 
— a  not  very  well  chosen  name,  as  this  material 
has  only  a  slight  analogy  to  what  is  called  the 
vascular  system  (or  network  of  blood-vessels)  in 
an  animal  body.  It  is  much  more  like  the  bony 
skeleton.  Similarly,  the  ribs  themselves  are 
usually  called  veins — a  very  bad  name  again, 
as  they  are  much  more  like  the  bones  of  a  wing 
or  hand ;  they  are  mainly  there  for  support,  as 
a  bony  or  wooden  framework,  though  they  also 
act  for  the  conveyance  of  sap  or  water. 

And  now  we  are  in  a  position  to  begin  to 
understand  the  various  shapes  of  leaves  as  we 
see  them  in  nature.  They  depend  most  of  all 
upon  certain  inherited  types  of  ribs  or  so-called 
veins,  and  these  types  are  usually  pretty  constant 


44        THE  STOEY  OF  THE  PLANTS. 

in  great  groups  of  plants  closely  related  by 
descent  to  one  another.  The  immense  difference 
in  their  external  shape  (which  often  varies  enor- 
mously even  on  the  same  stem)  is  mainly  due  to 
the  relative  extent  to  which  the  framework  is 
filled  out  or  not  with  living  cell-stuff,  or,  as  it  is 
technically  called,  cellular  tissue. 

There  are  two  chief  ways  of  arranging  the  ribs 
or  veins  in  a  leaf,  which  may  be  distinguished  as 
the  finger-like  and  the  feather-like  methods  (in 


FIG.  2. — FINGER-VEINED  LEAVES.  The  veins  are  the  same 
in  the  three  leaves,  but  they  differ  in  the  amount  to 
which  they  are  filled  in. 

technical  language,  palmate  and  pinnate}.  In 
the  finger -like  plan  the  ribs  all  diverge  from  a 
common  point,  more  or  less  radially.  In  the 
feather -like  plan  the  ribs  are  arranged  in  oppo- 
site pairs  along  the  sides  of  a  common  line  or 
midrib.  Yet  even  these  two  distinct  plans 
merge  into  one  another  by  imperceptible  de- 
grees, as  you  can  see  if  you  look  at  the  accom- 
panying diagram. 

Now  let  us  take  first  the  finger-veined  type 
(Fig.  2).  Here,  if  all  the  interstices  of  the  ribs 
are  fully  filled  out  with  cellular  tissue,  we  get  a 


HOW  PLANTS  EAf. 


45 


roundish  leaf  like  that  of  the  so-called  nastur- 
tium. But  if  the  ribs  project  a  little  at  the  edge 
— in  other  words,  if  the  cellular  tissue  does  not 
quite  fill  out  the  whole  space  between  them — 
we  get  a  slightly  indented  leaf,  like  that  of  the 
scarlet  geranium  or  the  common  mallow.  If  the 
unfilled  spaces  between  the  ends  of  the  ribs  are 
much  greater,  then  the  ribs  project  into  marked 
points  or  lobes,  and  we  get  a  leaf  like  that  of  ivy. 


FIG.  3. — FEATHER-VEINED  LEAVES.    The  four  leaves  have 
similar  veins,  but  are  differently  filled  in. 

Carry  the  starving  of  the  cellular  tissue  a  little 
further  still,  and  we  have  a  deeply-indented  leaf 
like  that  of  the  castor-oil  plant.  Finally,  let  the 
spaces  unfilled  go  right  down  to  the  common 
centre  from  which  the  ribs  radiate,  and  we  get  a 
divided  or  compound  leaf,  like  that  of  the  horse- 
chestnut,  with  three,  five,  or  seven  separate 
leaflets.  (See  Fig.  5,  No.  1.) 

Similarly  with  the  feather -veined  type  (Fig.  3) ; 
the  spaces  between  the  ribs  may  be  more  or  less 
filled  with  cellular  tissue  in  any  degree  you 


46  THE  STORY  OF  THE  PLANTS. 

choose  to  mention.     When  they  are  Very  fully 
filled  out,  you  get  a  leaf  like  that  of  bladder 


senna.     A   little   more  pointed,  and  less   filled 
out  at  the  tips,  it  becomes  like  argel.     When 


Ro\v 


EAT. 


the  edge  is  not  quite  filled  out,  but  irregularly 
indented,  we  get  forms  like  the  oak  leaf. 
Finally,  when  the  indentations  go  to  the  very 
bottom  of  each  vein,  so  as  to  reach  the  midrib, 
we  get  a  compound  leaf  like  that  of  the  vetch, 
with  a  number  of  opposite  and  distinct  leaflets. 

The  reason  why  some  leaves  are  thus  more 
filled  out  than  others  is  simply  this :  it  depends 
upon  the  freedom  of  their  access  to  air  and 
sunlight.  I  do  not  mean 
the  freedom  of  access  of 
the  particular  leaf  or  the 
particular  plant,  but  the 
average  ancestral  free- 
dom of  access  in  the  kind 
they  belong  to.  Each 
kind  has  adapted  itself, 

as  a  rule,  to  certain  situa-  FIQ.  6.— i.  Parallel  veins,  as 
tions  for  which  it  has  seen  in  one  great  group  of 
special  advantages,  and 
it  has  learnt  by  the  teach- 
ing of  natural  selection 
to  produce  such  leaves 
as  best  fit  its  chosen  site 
and  habits.  Where  access  to  carbon  and  sunlight 
is  easy,  plants  usually  produce  very  full  round 
leaves,  with  all  the  interstices  between  the  ribs 
filled  amply  in  with  cellular  tissue  ;  but  where 
access  is  difficult,  they  usually  produce  rather 
starved  and  unfilled  leaves,  which  consist,  as  it 
were,  of  scarcely  covered  skeletons  (Figs.  4  and 
5).  This  last  condition  is  particularly  observable 
in  submerged  leaves,  and  in  those  which  grow 
in  very  crowded  situations. 


plants,  the  lilies.  II. 
Branching  veins,  as  seen 
in  another  great  group, 
the  trees  and  herbs  of  the 
usual  type. 


48  THE  STOKY  OF  THE  PLANTS. 

The  two  types  of  rib-arrangement  to  which  I 
have  already  called  attention  exist  for  the  most 
part  in  one  of  the  two  great  groups  of  flowering 
plants  about  which  I  shall  have  more  to  say  to 
you  hereafter.  There  is  yet  a  third  type,  how- 
ever, which  occurs  in  the  other  great  group  (that 
of  the  grasses  and  lilies),  and  it  is  known  as  the 
parallel  (Fig.  6).  In  this  type,  the  ribs  do  not 
form  a  radiating  network  at  all,  but  run  straight, 
or  nearly  so,  through  the  leaves.  Examples  of 
it  occur  in  almost  all  grasses,  and  in  tulips, 
daffodils,  lily  of  the  valley,  and  narcissus.  Leaves 
of  this  sort  have  seldom  any  leaf-stalk ;  they 
usually  rise  straight  out  of  the  ground,  more  or 
less  erect,  and  their  architectural  plan  is  gene- 
rally quite  simple.  They  are  seldom  toothed, 
and  hardly  ever  divided  into  deeply- cut  segments 
or  separate  leaflets. 

A  few  more  peculiarities  in  the  shapes  of 
leaves  must  still  be  noted,  and  a  few  words 
used  in  describing  them  must  be  explained  very 
briefly.  When  the  leaf  consists  all  of  one  piece, 
no  matter  how  much  cut  up  and  indented  at  the 
edge,  it  is  said  to  be  "simple";  but  if  it  is 
divided  into  distinct  leaflets  (as  in  Fig.  5),  it  is 
called  "compound."  If  the  edge  is  unindented 
all  round  (as  in  Fig.  6),  we  say  the  leaf  is  "  en- 
tire "  ;  if  the  ribs  form  small  projections  at  the 
edge  (as  in  Fig.  4),  we  call  it  "  toothed  "  ;  if  the 
divisions  are  deeper,  we  say  it  is  "lobed"  ;  and 
when  the  lobes  are  very  deeply  cut  indeed,  we 
call  it  "dissected."  Thus,  in  order  to  describe 
accurately  the  shape  of  a  leaf,  we  need  only  say 
which  way  it  is  veined  or  ribbed — whether  finger- 


ttOW   PLANTS   EAtf.  49 

wise,  feather- wise,  or  with  parallel  veins — and 
how  much,  if  at  all,  it  is  cut  or  divided. 

Endless  varieties,  however,  occur,  in  accord- 
ance with  the  peculiar  place  the  plant  and  its 
kind  have  been  developed  to  inhabit.  In 
climbing  plants,  for  example,  the  leaves  are 
usually  opposite,  so  as  to  clutch  more  readily, 
and  they  are  almost  always  more  or  less  heart- 
shaped  at  the  base,  as  in  convolvulus  and  black 
briony.  The  leaves  of  forest  trees,  on  the  other 
hand,  tend  to  be  what  is  known  as  ovate  in 
shape,  like  the  beech  and  the  poplar ;  while 
those  of  the  lime  are  a  little  one-sided,  in  order 
that  each  leaf  may  not  overshadow  and  rob  its 
neighbour.  This  one-sidedness  is  even  more 
markedly  seen  in  the  hot-house  begonias.  Some 
leaves,  again,  are  minutely  subdivided  into 
leaflets  twice  or  three  times  over ;  such  leaves 
are  said  to  be  doubly  or  trebly  compound.  But 
if  you  study  plants  as  they  grow  (and  this  book 
is  written  in  the  hope  that  it  may  induce  you  to 
do  so),  you  will  generally  be  able  to  see  that  the 
shapes  and  peculiarities  of  leaves  have  some 
obvious  reference  to  their  place  in  the  world, 
and  their  habits  and  manners. 

I  have  spoken  so  far  mainly  of  quite  central 
and  typical  leaves,  which  are  arranged  with  a 
single  view  to  the  need  for  feeding.  But  plants 
are  exposed  to  many  dangers  in  life  besides  the 
danger  of  starvation,  and  they  guard  in  various 
ways  against  all  these  dangers.  One  very 
obvious  one  is  the  danger  of  being  devoured 
by  grazing  animals,  and,  to  protect  themselves 
4 


50  THE  STOKY  OF  THE  PLANTS. 

against  it,  many  plants  produce  leaves  which  are 
prickly,  or  stinging,  or  otherwise  unpleasant. 
The  common  holly  is  a  familiar  instance.  In 
this  case  the  ribs  are  prolonged  into  stiff  and 
prickly  points,  which  wound  the  tender  noses 
of  donkeys  or  cattle.  We  can  easily  see  how 
such  a  protection  could  be  acquired  by  the 
holly-bush  through  the  action  of  Variation  and 
Natural  Selection.  For  holly  grows  chiefly  in 
rough  and  wild  spots,  where  all  the  green  leaves 
are  liable  to  be  eaten  by  herbivorous  animals. 
If,  therefore,  any  plant  showed  the  slightest 
tendency  towards  prickliness  or  thorniness,  it 
would  be  more  likely  to  survive  than  its  un- 
protected neighbours.  And  indeed,  as  a  matter 
of  fact,  you  will  soon  see  that  almost  all  the 
bushes  and  shrubs  which  frequent  commons, 
such  as  gorse,  butcher's  broom,  hawthorn, 
blackthorn,  and  heather,  are  more  or  less  spiny, 
though  in  most  of  these  cases  it  is  the  branches, 
not  the  leaves,  that  form  the  defensive  element. 
Holly,  however,  wastes  no  unnecessary  material 
on  defensive  spikes ;  for  though  the  lower  leaves, 
within  reach  of  the  cattle  and  donkeys,  are  very 
prickly  indeed,  you  will  find,  if  you  look,  that 
jthe  upper  ones,  above  six  or  eight  feet  from  the 
/ground,  are  smooth-edged  and  harmless.  These 
upper  leaves  stand  in  no  practical  danger  of 
being  eaten,  and  the  holly  therefore  takes  care 
to  throw  away  no  valuable  material  in  protecting 
them  from  a  wholly  imaginary  assailant. 

Often,  too,  in  these  prickly  plants  we  can 
trace  some  memorial  of  their  earlier  history. 
Gorse,  for  example,  is  a  peaflower^*by  family,  a 


HOW  PLANTS   EAT.  51 

member  of  the  great  group  of  "papilionaceous," 
or  butterfly-blossomed,  plants,  which  includes 
the  pea,  the  bean,  the  laburnum,  the  clover,  and 
many  other  familiar  trees,  shrubs,  and  climbers. 
It  is  descended  more  immediately  from  a  special 
set  of  trefoil-leaved  peaflowers,  like  the  clovers 
and  lucernes  ;  but,  owing  to  its  chosen  home  on 
open  uplands,  almost  all  its  upper  leaves  have 
been  transformed  for  purposes  of  defence  into 
sharp,  spine-like  prickles.  Indeed,  the  leaves 
and  branches  are  both  prickly  together,  so  that 
it  is  difficult  at  first  sight  to  discriminate  between 
them.  But  if  you  take  a  seedling  gorse  plant 
you  will  find  that  in  its  early  stages  it  still  pro- 
duces trefoil  leaves,  like  its  clover-like  ancestors; 
and  these  leaves  are  almost  exactly  similar  to 
those  of  the  common  genista  so  much  cultivated 
in  hot-houses.  As  the  plant  grows,  however, 
the  trefoil  leaves  gradually  give  place  to  long 
and  narrow  blades,  and  these  in  turn  to  prickly 
spines,  like  the  adult  gorse-leaves.  Hence  we 
'are  justified  in  believing  that  the  ancestors  of 
gorse  were  once  genistas,  bearing  trefoil  leaves  ; 
and  that  later,  through  the  action  of  natural 
selection,  the  prickliest  among  them  survived, 
till  they  acquired  their  existing  spiny  foliage. 
In  every  case,  indeed,  young  plants  tend  to  re-  j 
semble  their  earlier  ancestors,  and  only  as  they  I 
grow  up  acquire  their  later  and  more  special 
characteristics. 

And  now  I  must  add  one  word  about  the 
origin  of  leaves  in  general.  Very  simple  plants, 
we  saw,  consist  of  a  single  cell,  which  is  not 


52        THE  STORY  OF  THE  PLANTS. 

merely  a  leaf,  but  also  at  the  s;ime  time  a  flower, 
a  seed,  a  root,  a  branch,-  and  everything.  In 
other  words,  in  very  simple  plantslT single  cell 
does  rather  badly,  everything  which  in  more 
advancecTand  developed  "plan  is  is  better  done  by 
distinct  and  highly-adapted  organs.  The  whole 
evolution  of  plants  consists,  in  fact,  injbhe  tellmg 
off  of  particular  parts  to  do  betterwhat  $ie 
primitive  cell  did  for  itself  but  badly.  Above 
the  very  simple  plants  which  consist  of  a  single 
cell  come  other  plants,  which  consist  of  many 
cells  glace^^n^^n^ri^togejher^  as  in  the  case 
of  the  HhaTr  like"  water- weeds ;  and  above  these 
again  come  other  and  rather  higher  plants,  in 
which  the  cellular  tissue  assumes  the  form  of  a 
flat  and  leaf-like  blade,  as  in  many  broad  sea- 
weeds. None  of  these,  however,  are  called 
leaves  in  the  strict  sense,  because  they  consist 
of  cells  alone,  without  any  ribs  or  supporting 
framework.  The  higher  types,  however,  like 
ferns  and  flowering  plants,  have  such  ribs  or 
frameworks,  made  of  that  stiffer  and  tougher 
material  called  vascular  tissue.  This  is  the 
most  general  distinction  that  exists  between 
plants ;  the  higher  ones  are  knowrn  as  Vascular 
Plants,  including  all  those  with  true  leaves,  such 
as  the  common  trees,  herbs,  and  shrubs,  and  the 
ferns  and  grasses — in  fact,  almost  all  the  things 
ever  thought  of  as  plants  by  most  ordinary 
observers ;  the  lower  ones  are  known  as  Cellular 
Plants,  and  include  the  kinds  without  true 
. leaves  or  vascular  tissue,  such  as  the  seaweeds, 
fungi,  and  microscopic  plants  only  recognised 
as  a  rule  by  botanical  students. 


HOW   PLANTS   EAT.  53 

The  higher  plants,  then,  have  for  the  most 
part  special  organs,  the  leaves,  told  off  to  do 
work  for  them  as  mouths  and  stomachs;  while 
other  organs  are  told  off  to  do  other  special  work 
of  their  own — as  the  roots  to  drink,  the  flowers 
to  reproduce,  the  fruit  and  seeds  to  carry  on  the 
life  of  the  species  to  other  generations,  and  so 
forth,  down  to  the  hairs  that  protect  the  surface, 
or  the  glands  that  produce  honey  to  attract  the 
fertilising  insects.  To  the  end,  however,  all 
parts  of  the  plant  retain  the  power  to  eat  car- 
bonic acid,  if  necessary ;  so  that  many  higher 
plants  have  no  true  leaves,  but  use  portions  of 
\  the  stem  or  branches  for  the  purpose  of  feeding. 
Any  part  of  the  plant  which  contains  the  active 
living  green- stuff?  or  chlorophyll,  can  perform 
the  f unctiomT'bi  a  leaf.  In  very  dry  or  desert 
places,  leaves  would  be  useless,  because  their 
flat  and  exposed  blades  would  allow  the  water 
within  to  evaporate,  too  readily.  Hence  most 
desert  plants,  like  the  cactuses,  and  many  kinds 
of  acacias  and  euphorbias,  have  no  true  leaves 
at  all ;  in  their  place  they  have  thick  and  fleshy 
stgms,  often  very  leaf -like  in  shape,  and  curiously 
jointed.  These  stems  are  covered  with  a  thick, 
transparent  skin  or  epidermis,  to  resist  evapora- 
tion, and  are  protected  by  numerous  stinging 
hairs  or  spines,  which  serve  to  keep  off  the 
attacks  of  animals.  Stems  of  this  type  are  used 
as  reservoirs  of  water,  which  the  plant  sucks  up 
during  the  infrequent  rains  ;  and  as  they  con- 
tain chlorophyll,  like  leaves,  they  serve  in  just 
the  same  way  as  swallpwers  and  digesters  o^ 
carbonic  acid. 


54:  THE    STOEY   OF    THE    PLANTS. 

Many  other  plants  which  live  in  dry  or  sandy 
places,  like  our  common  English  stone-crops,  do 
not  go  quite  as  far  as  the  cactuses,  but  have 
thick  and  fleshy  leaves  on  thick  and  fleshy  stems, 
to  prevent  evaporation.  As  a  general  rule,  in- 
deed, the  drier  the  situation  a  plant  habitually 
frequents  the  fleshier  are  its  leaves,  and  the 
greater  its  tendency  to  make  the  stem  share  in 
the  work  of  feeding,  or  even  to  get  rid  of  foliage 
altogether.  In  Australia,  however,  most  of  the 
forest  trees,  like  the  eucalyptuses,  have  got  over 
the  same  difficulty  in  a  different  way ;  they  arrange 
their  leaves  on  the  stem  so  as  to  stand  vertically 
to  the  sun's  rays,  instead  of  horizontally,  which 
saves  evaporation,  and  makes  the  woodland 
almost  entirely  shadeless.  Many  of  these  Aus- 
tralian trees,  however,  have  no  true  leaves,  but 
use  in  their  place  flattened  green  branches. 

Some  plants  are  annuals,  and  some  peren- 
nials. When  annuals  have  flowered  and  set 
their  seed  they  wither  and  die.  But  perennials 
go  on  for  several  seasons.  Most  of  them,  how- 
ever, in  cold  climates  at  least,  shed  their  leaves 
on  the  approach  of  winter.  But  they  do  not 

•  lose  all  the  valuable  material  stored  up  in  them. 

f  Trees  and  shrubs  withdraw  the  starchy  matter 
into  a  special  layer  of  the  bark,  where  it  remains 

;  safe  from  the  winter  frosts,  and  is  used  up  again 
in  spring  in  forming  the  new  foliage.  This  new 
foliage  is  usually  provided  for  in  the  preceding 
season.  If  you  look  at  a  tree  in  late  autumn, 
after  the  leaves  have  fallen,  you  will  see  that  it 
is  covered  by  little  knobs  which  we  know  as 


HOW   PLANTS    EAT.  55 

buds.  These  buds  are  the  foliage  of  the  coming 
season.  The  outer  part  consists  of  several 
layers  of  dry  brown  scales,  which  serve  as  an 
overcoat  to  protect  the  tender  young  leaves 
within  from  the  chilly  weather.  But  the  inner 
layers  consist  of  the  delicate  young  leaves  them- 
selves, which  are  destined  to  sprout  and  grow 
as  soon  as  spring  comes  round  again.  Even 
the  scales,  indeed,  are  very  small  leaves,  with 
no  living  material  in  them  ;  they  are  sacrificed 
ByTKe"  plant,  as  it  were,  in  order  to  keep  the 
truer  leaves  within  snug  and  warm  for  the 
winter.  Nor  do  the  autumn  leaves  fall  off  by 
pure  accident ;  some  time  before  they  drop  the 
tree  arranges  for  their  fall  by  making  a  special 
row  of  empty  cells  where  the  leaf -stalk  joins  the 
stem  or  branch ;  and  when  frost  comes  on,  the 
leaf  separates  quietly  and  naturally  at  that  point, 
as  soon  as  the  valuable  starchy  and  living 
material  has  been  withdrawn  and  stored  in  the 
permanent  layers  of  the  bark  for  future  service. 

Smaller  and  more  succulent  plants  do  not 
thus  withdraw  their  living  material  into  the 
bark  in  autumn  ;  but  they  attain  much  the  same 
end  in  different  manners.  Thus  lilies  and 
onions  store  the  surplus  material  they  lay  by 
during  the  summer  at  the  base  of  their  long 
leaves,  and  the  swollen  bases  thus  formed  pro- 
duce what  we  call  a  bulb,  which  carries  on  the 
life  of  the  plant  to  the  next  season.  Other 
plants,  like  the  common  English  orchids,  store 
material  in  underground  tubers;  while  others, 
again,  and  by  far  the  greater  number,  so  store 
it  in  the  root,  which  is  sometimes  thick  and 


56        THE  STORY  OP  THE  PLANTS. 

swollen,  or  in  an  underground  stem  or  root- 
stock.  In  most  cases,  however,  perennial 
plants  take  care  to  keep  over  their  live  material 
from  one  season  to  the  other  by  some  such 
means  of  permanent  storage.  They  are,  so  to 
speak,  capitalists.  Natural  selection  has  of 
course  preserved  those  plants  which  thus  laid 
by  for  the  future,  and  has  killed  out  the  mere 
spendthrifts  which  were'  satisfied  to  live  for  the 
fleeting  moment  only.  The  soil  of  our  meadows 
in  winter  is  full  of  tubers,  bulbs,  and  root- 
stocks  ;  while  our  shrubs  and  trees  carry  over 
their  capital  from  season  to  season  in  their 
living  bark,  secure  from  injury.  In  one  way  or 
another  all  our  perennial  plants  manage  to  tide 
their  living  green-stuff,  or  at  least  its  raw 
material,  by  hook  or  by  crook,  over  the  dangers 
of  winter. 

I  have  given  so  much  space  to  the  subject  of 
leaves  because,  as  you  must  see,  the  leaf  is 
really  the  most  important  and  essential  part  of 
the  entire  plant — the  part  for  whose  sake  all  the 
rest  exists,  and  in  which  the  main  work  of 
making  living  material  out  of  lifeless  carbonic 
acid  and  water  is  concentrated. 

Let  us  sum  up  briefly  the  main  facts  we  have 
learned  in  this  long  chapter. 

Plants  eat  carbonic  acid  under  the  influence 
of  sunlight.  They  store  up  the  solar  energy 
thus  derived  in  starches  and  green-stuff  in  their 
own  bodies.  Very  simple  plants,  which  float 
freely  in  water,  eat  and  drink  with  all  portions 
of  their  surface,  But  higher  plants  eat  with 


HOW   PLANTS   DRINK.  57 

special  organs.  These  organs  are  known  as 
leaves,  and  are  the  parts  where  the  chief  busi- 
ness of  the  plant  is  transacted. 

A  leaf  is  an  expanded  mass  of  cells,  containing 
living  green-stuff,  supported  on  a  tougher  frame- 
work, or  rib-like  skeleton.  Leaves  take  in  car- 
bonic acid  by  means  of  tiny  absorbing  mouths, 
which  exist  on  their  upper  surface  ;  and  they 
turn  loose  most  of  the  oxygen,  by  the  aid  of 
sunlight,  building  up  the  carbon  into  starch, 
with  hydrogen  from  the  water  supplied  by  the 
roots  to  them.  Leaves  are  of  different  shapes, 
according  to  the  work  they  have  to  do  for  the 
plant  in  different  situations.  Where  carbon  and 
sunlight  abound  they  are  round,  or  nearly  so  ; 
where  carbon  and  sunlight  are  scanty,  or  much 
competed  for,  they  are  more  or  less  divided  into 
minute  sections. 

CHAPTER  V. 

HOW   PLANTS    DRINK. 

WE  have  now  learnt  that  plants  really  eat  for 
the  most  part  with  their  leaves.  They  grow,  on 
the  whole,  out  of  the  air,  not,  as  most  people 
seem  to  fancy,  out  of  the  soil.  Yet  you  must 
have  noticed  that  farmers  and  gardeners  think  a 
great  deal  about  the  ground  in  which  they  plant 
things,  and  very  little,  apparently,  about  the  air 
around  them.  What  is  the  reason  for  this 
curious  neglect  of  the  real  food  of  plants,  and 
this  curious  importance  attached  to  the  mould, 
or  soil  they  root  in  ? 


58         THE  STORY  OF  THE  PLANTS. 

That  is  the  question  we  shall  have  to  consider 
in  the  present  chapter  ;  and  I  shall  answer  it  in 
part  at  once  by  saying  beforehand  that,  though 
plants  do  grow  for  the  most  part  out  of  the  car- 
bonic acid  supplied  by  the  air  to  the  leaves,  they 
also  require  certain  things  from  the  soil,  less 
important  in  bulk,  but  extremely  necessary  for 
their  growth  and  development.  What  they  eat 
through  their  leaves  is  far  the  greatest  in 
amount ;  but  what  they  drink  through  their 
roots  is  nevertheless  indispensable  for  the  pro- 
duction of  that  living  green-stuff,  chlorophyll, 
which,  as  we  saw,  is  the  original  manufacturer 
1  and  prime  maker  of  all  the  material  of  life,  either 
vegetable  or  animal. 

Plants  have  roots.  These  roots  perform  for 
them  two  or  three  separate  functions.  They 
fix  the  plant  firmly  in  the  soil ;  they  suck  up 
the  water  which  circulates  in  the  sap ;  and  they 
also  gather  in  solution  certain  other  materials 
which  are  necessary  parts  of  the  plant's  living 
matter. 

The  first  and  most  obvious  function  of  the 
root  is  to  fix  the  plant  firmly  in  the  soil  it  grows 
in.  Very  early  floating  plants,  of  course,  have 
no  roots  at  all ;  they  take  in  water  and  the 
dissolved  materials  it  contains,  with  every  part 
of  their  surface  equally,  just  as  they  take  in 
carbonic  acid  with  every  part  of  their  surface 
equally.  They  are  all  root,  all  leaf,  all  flower, 
all  fruit.  But  higher  plants  tend  to  produce 
different  organs,  which  have  become  specially 


HOW   PLANTS   DEINK.  59 

adapted  by  natural  selection  for  special  purposes. 
If  you  sow  a  pea  or  bean  you  will  find  at  once 
that  the  young  seedling  begins  from  the  very 
first  to  distinguish  carefully  between  two  main 
parts  of  its  body.  In  one  direction,  it  pushes 
downward,  forming  a  tiny  root,  which  insinuates 
itself  with  care  among  the  stones  and  soil ;  in 
the  other  direction,  it  pushes  upward,  forming  a 
baby  stem,  which  gradually  clothes  itself  with 
leaves  and  flowers. 

The  tip  of  the  root  is  the  part  of  the  plant 
which  exercises  the  greatest  discrimination  and 
ingenuity,  so  much  so  that  Darwin  likened  it  to 
the  brain  of  animals.  For  it  goes  feeling  its 
way  underground,  touching  here,  recoiling  there, 
insinuating  little  fingers  among  pebbles  and 
crannies,  and  trying  its  best  by  endless  offshoots 
to  fix  the  plant  with  perfect  security.  Large 
trees,  in  particular,  need  very  firm  roots,  to  moor 
them  in  their  places,  and  withstand  the  force  of 
the  winds  to  which  they  are  often  subject.  After 
every  great  storm,  as  we  know,  big  oaks  and 
pines  may  be  seen  uprooted  by  the  power  of 
this  invisible  but  very  dangerous  enemy. 

The  root,  however,  does  not  serve  merely  to 
anchor  the  plant  to  one  spot,  and  secure  it  a 
place  in  which  to  grow  and  feed  ;  it  also  drinks 
water.  The  hairs  and  tips  of  the  root  absorb 
moisture  from  the  soil ;  and  this  water  circulates 
freely  as  sap  through  the  entire  plant,  dissolving 
and  carrying  with  it  the  starches  and  other 
materials  which  each  part  requires  for  its  growth 
find  nourishment  (Figs.  7,  8,  and  9),  Without 


60 


THE    STORY   OF   THE    PLANTS. 


water,  as  we  all  know,  plants  will  wither  and 
die ;  and  the  roots  push  downward  and  outward 
in  every  direction  in  search  of  this  necessary  of 
life  for  the  leaves  and  flowers. 

In  addition  to 
these  two  functions 
of  fixing  the  plant 
and  drinking  water, 
however,  roots  per- 
form a  third  and 
almost  more  impor- 
tant one  in  absorbing 
the  other  needful 
materials  of  plant  life 
from  the  soil  about 
them.  They  drink, 
not  water  alone,  but 
other  things  dis- 
solved in  it. 

What  are  these 
other  things?  Well, 
the  answer  to  that 
question  will  fairly 
round  off  our  first 
rough  idea  of  the 
raw  materials  that 
life  is  made  up  from. 

Fig.     7.       ROOT     OF     THE      CARROT.    AT, 

Fig.  8.  ROOT  OF  THE  FRooBiT,  We  saw  already  that 
FLOATING  IN  WATER.  Fig.  9.  plants  eat  carbon  and 
ROOT  OF  THE  RADISH.  The  hydrogen  from  the 
small  hair-like  ends  drink  in  air  ancj  water  .  out  of 
water  and  dissolved  food-salts.  tj>e^  they  manufac- 

ture   a  large   number  of   compounds,    such   as 


FIG.  7. 


FIG.  8. 


FIG.  9. 


HOW   PLANTS   DBINK. 


61 


'starches,  oils,  sugars,  and  so  forth,  all  of  which 
contain  a  littlc^oxygerjL,  but  far  less  than  the 
amount  containcHTnthe  carbonic  acid  and  water 
from  which  they  are  manufactured.     These  use- 
:ul  materials,  however,  though  possessing  energy, 
ihat  is  to  say  the  power^f-prddufijag  light  and\  / 
jeat^  and  motion,    are   not   exactly  livc^ stuffs ;  fa 
n  orfleyKPPSRtairi^c^^ 

1  Jsrtuff  of  all  tSBies,  animal  or  vegetable?)  proto- 
plasm,  we  must  have  a  four  lit.  dement,  \rntr  on  en  ;\ 
ind  that  element  is  supplied  by  tTiefTrlB  r  m* 
;olution. 

^o  now  you  see  the  full  importance  of  the\ 

" "  K  fc e  °^s  an<^  s*arcnes  manu-  / 

lactured  in  'the  '"^g|ivea\that  mysterious  body,  r 
nitrogen,  which  isnecessary'  Th"*^r3er  to  turn  \ 
these'tmngsmtQ  protoplasm  and  chlorophyll.  T> 

A  i'ew  offier"  things  besides  nitrogen  are  also 
needed  by  the  plant  from  the  soil ;  the  most 
important  of  these  are  apljlnrr  and  pfcosjgfcprns. 
The  plant,  however,  does  not  take  in  these 
substances  in  their  free  or  simple  form,  as 
nitrogen,  sulphur,  and  phosphorus,  but  in  com- 
position, as  soluble ,  nitrates,  sulphates,  and 
phosphates. 

Now,  I  am  not  going  to  trouble  you  with  a. 
long  chemical  account  of  how  the  plant  combines, 
these  various  materials — a  thing  about  which 
even  chemists  and  botanists  themselves  know  as 
yet  but  very  little.  It  will  be  enough  to  say 
here  that  the  \planti  builds  them  up  at  last  into  f 
.ex  body,  called  protoplasm  ;  f 


an  extremely  co? 


62  THE  STO&Y  OF  THE  PLANTS. 

livi 

tnmg  whihout 


\ 


and  this  Qrotoplasnjjs  thevultimate  living  matter, 
the  "  physicaT  basis  of  lii'e  ;      the 


which   there   could   be_  no    plants 
possible. 

What    is   protoplasm — this   mysterious    stuff, 
whferl  builds  up  the  bodies  of  plants  and  animals  ? 
^It  is  a  curious  transparent  jelly-like  substance, 
full  of  tiny  microscopic  grains,  and  composed  of 

Sometimes  it  is  almost  watery,  sometimes  half- 
horny,  but  as  a  rule  it  is  waxy  or  soft  in  texture. 
It  is  very  plastic.  Its  peculiar  characteristic  is 
that  it  is  restlessly  alive,  so  to  speak  ;  seen  under 
a  microscope,  it  moves  about  uneasily,  with  a 
strange  streaming  motion,  as  if  in  search  of 
something  it  wanted.  It  is,  in  point  of  fact,  the 
building-material  of  life  ;  and  out  of  it  the  living 
parts  of  every  creature  that  lives,  whetner  animal 
or  vegetable,  are  framed  and  compounded. 

/  But  it  is  plants  alone  that  know  how  to  make 
protoplasm.  Animals  can  only  take  it  ready- 

JL>  made,  -from  planta.  and  burn  it  up  again  6y 
feumonwitri  oxygen  in  their  own  bodies.  The 
jplant  manufactures  it.  The  animal  destroys  it. 
Chlorophyll  or  the  active  green-stuff  of  leaves  is 
a  special  modification  or  ^ariety  of  protoplasm ; 
and  chlorophyll \alon o/  possesses  the  power  to 
manufacture 


. 

material,  under  the  influence  of  sunlight,  from 
the  .dead  and  inert  bodies  around  it.  The 
materials  which  it  thus  produces  are  afterwards 

worked  up  by  the  plant,  together  with  the 
nitrogen,  sulphur,  and  phosphorus  supplied  by 
the  roots,  into  fresh  protoplasm  and  fresh 


HOW   PLANTS   DBINK.  63 

chlorophyll.  These  the  animal  may  afterwards 
eat,  either  in  the  form  of  leaves  like  grass,  or  in 
the  form  of  seeds  or  fruits,  like  corn,  rice,  or 
bananas. 

The  tiniest  primitive  one-celled  plant  con- 
tains protoplasm  and  chlorophyll  (though  a 
few  degenerate  plants,  like  fungi,  have  none 
of  the  living  green-stuff,  and  can  make  nonejL 
living  material  for  themselves,  but  depenHTTike 
animals,  upon  the  industry  of  others).  Every 
living  cell  of  every  plant  contains  protoplasm  ;  a 
cell  without  anyls  dead  and  lifeless.  Protoplasm, 
in  short,  is  the  only  living  material  we  know;  and 
its  life  constitutes  fne 
compounded  of  it. 

Well,  now  you  are  in  a  position  to  see  why 
the  farmer  and  the  gardener  attach  so  much 
importance  to  the  soil,  and  so  little,  apparently, 
to  the  air  and  the  sunlight.  The  reason  is  that 
the  air  is  everywhere  ;  you  get  it  for  nothing ; 
but  the  soil  costs  money,  and,  when  cultivated, 
it  requires  to  be  supplied  from  time  to  time  with 
fresh  stores  of  the  particular  materials  the  plants 
take  from  it. 

Let  me  give  two  simple  parallel  cases.  A  fire 
is  made  by  the  combination  of  two  sorts  of  fuel — 
coal  and  oxygen.  One  is  just  as  necessary  for 
fire-making  as  the  other.  But  we  buy  coal  dear, 
and  we  neglect  to  take  oxygen  into  consideration 
accordingly.  The  reason  is  that  oxygen  exists 
in  abundance  everywhere ;  so  we  don't  have  to 
buy  it.  If  we  paid  a  pound  a  ton  for  it,  as  we 
do  with  coal,  we  should  very  soon  remember 


t>4  THIS    STOliY   OF   THE   fLANTtJ. 

how  necessary  a  part  it  is  of  every  tire.  Even 
at  present  we  are  obliged  to  provide  for  its  free 
admission  by  the  bars  of  the  grate,  and  by 
checking  or  regulating  its  ingress  we  can 
slacken  or  quicken  the  burning  of  the  fire. 

Or,  to  take  another  analogy,  oxygen  is  just  as 
necessary  to  human  beings  and  other  animals  as 
food  and  drink  are.  But,  as  a  rule,  we  get 
•oxygen  everywhere  in  such  great  abundance 
that  we  never  think  of  taking  it  into  practical 
consideration.  Still,  in  the  Black  Hole  of  Cal- 
cutta, the  unhappy  prisoners  thoroughly  realised 
the  full  value  of  oxygen,  and  would  gladly  have 
paid  its  weight  in  gold  for  the  life-giving 
element. 

Now,  carbonic  acid,  on  which  plants  mainly 
live,  is  not  so  common  or  so  abundant  a  gas 
as  oxygen ;  but  still,  it  exists  in  considerable 
quantities  in  the  air  everywhere.  So  most  plants 
are  able  to  get  almost  as  much  as  they  need  of 
it.  Nevertheless,  submerged  plants,  and  plants 
that  grow  in  very  crowded  places,  seem  to  com- 
pete hard  with  one  another  for  this  aerial  food ; 
and  in  certain  cases  they  appear  to  live,  as  it 
were,  in  a  very  Black  Hole  of  Calcutta,  so  far  as 
regards  the  supply  of  this  necessary  material. 
In  farms  and  gardens,  however,  the  farmer  takes 
care  that  every  plant  shall  have  plenty  of  room 
and  space — in  other  words,  free  access  to  sun- 
light and  carbonic  acid.  He  "  gives  the  plants 
air,"  as  he  says,  not  knowing  that  he  is  really 
supplying  them  with  their  aerial  food- stuff.  He 
does  this  by  keeping  down  weeds — by  ploughing, 
by  digging,  by  hoeing,  or  tilling.  Indeed,  what 


HOW   PLANTS   DKINK.  65 

do  we  really  mean  by  cultivation  ?  Nothing 
more  than  destroying  the  native  vegetation  of  a 
place,  in  order  to  make  room  for  other  plants 
that  we  desire  to  multiply.  We  plough  out  the 
grasses  and  herbs  that  occupy  the  soil ;  we  sow 
or  plant  thinly  seeds  or  cuttings  of  corn  or  vines 
or  potatoes  that  \ve  desire  to  propagate.  We 
give  these  new  plants  plenty  of  space  and  air — - 
in  other  words,  free  access  to  sunlight  and  car- 
bonic acid.  And  that  is  the  fumHameritar  basis 
of"  cultivation — to  keep  down  certain  natural 
plants  of  the  place,  in  order  to  give  free  room 
to  others. 

But  as  the  crop-plants  require  to  root  them- 
selves, the  farmer  naturally  thinks  most  of  the 
soil  they  root  in — which  he  has  to  buy  or  rent, 
while  the  carbonic  acid  comes  freely  to  him, 
unperceived,  with  the  breath  of  heaven.  Where 
water  is  scarce,  as  in  irrigated  desert  lands,  the 
farmer  recognises  quite  equally  the  importance 
of  water.  But  he  never  recognises  the  true 
importance  of  carbonic  acid.  That  is  why  most 
people  wrongly  imagine  that  plants  grow  out  of 
the  soil,  not  out  of  the  air.  Still,  when  we  burn 
them,  the  truth  becomes  clear.  The  portion  of 
the  plants  derived  from  air  and  water  goes  off 
again  into  the  air  in  the  act  of  burning :  so  too 
does  the  nitrogen  :  the  remaining  portion  derived 
direct  from  the  soil  is  only  the  insignificant  resi- 
due returned  to  the  soil  as  ash  when  we  burn  the 
plant  up. 

Nevertheless,  the  farmer  often  needs  to  supply 
certain  raw  materials  to  the  soil  for  the  plants 
5 


66         THE  STORY  OF  THE  PLANTS. 

he  cultivates.  These  raw  materials  are  called 
manures  ;  they  are  mostly  rich^in.  nitrate,  pi ^  aa^- 
phosghatesj  and  as  they  are  usually  the  only 
tEings^ directly  supplied  to  plants  by  human 
agency — the  carbonic  acid  and  water  being 
supplied  by  wind  and  rain  in  the  ordinary 
course  of  nature — they  help  to  strengthen  the 
popular  misapprehension  that  plants  grow 
directly  out  of  the  soil.  Manures  consist  chiefly 
of  compounds  of  nitrogen,  phosphorus,  and  pot- 
ash. These  are  the  things  of  which  the  plants 
take  most  from  the  soil ;  and  when  the  crops 
are  cut  down  and  carried  away,  it  becomes 
necessary  to  restore  them.  This  is  generally 
done  by  means  of  farmyard  manure,  bones,  or 
guano.  Most  manures  are  really  the  remains 
or  droppings  of  animals ;  so  that  when  we  lay 
them  on  the  soil,  we  are  merely  returning  to  it 
in  another  form  what  the  animal  took  from  it 
when  he  eat  the  plants  up. 

All  plants,  however,  do  not  equally  exhaust 
the  soil  of  all  necessary  materials.  Some  require 
one  sort  of  food,  and  others  another.  That  is 
why  farmers  have  recourse  to  what  is  called 
rotation  of  crops,  so  as  to  follow  up  one  sort  of 
plant  in  a  field  by  another,  whose  needs  are 
different.  Thus  corn  is  alternated  with  swedes 
or  turnips.  Virgin  soil  will  produce  crops  for 
several  seasons  together  without  the  need  for 
manuring ;  but  when  many  crops  have  been  cut 
from  it  in  succession,  the  earth  gets  exhausted 
of  nitrates  and  phosphates,  and  then  it  becomes 
necessary  to  manure  and  to  rotate  the  crops  in  the 
ordinary  manner. 


HOW   PLANTS    DRINK.  67 

But  in  nature  crops  are  not,  as  a  rule,  removed 
from  the  soil ;  they  die  and  wither,  and  return 
to  it  for  the  most  part  whatever  they  took  from 
it.  The  dead  birds  and  insects,  and  the  droppings 
of  animals,  are  sufficient  manure  for  the  native 
woodland.  Still,  even  in  nature,  certain  plants 
more  or  less  exhaust  the  soil  of  certain  valuable 
materials;  and  therefore  natural  selection  has 
secured  a  sort  of  roundabout  rotation  of  crops 
in  a  way  of  which  I  shall  have  more  to  say  here- 
after. Many  plants,  for  example,  which  greatly 
exhaust  the  soil,  have  winged  or  feathery  seeds ; 
and  these  seeds  are  carried  by  the  wind  to  fresh 
spots,  where  they  alight  and  root  themselves,  in 
order  to  escape  the  exhausted  soil  in  the  neigh- 
bourhood of  their  mothers.  Other  plants  send 
out  runners,  as  they  are  called,  on  long  trailing 
branches,  which  root  at  a  distance,  and  so  start 
fresh  lives  in  unexhausted  places.  Yet  others 
have  tubers,  which  shift  their  place  from  year 
to  year ;  or  they  push  forth  underground  suckers, 
which  become  new  plants  at  a  distance  from  the 
parent.  All  these  are  different  natural  ways  for 
obtaining  what  is  practically  rotation  of  crops ; 
nature  invented  that  plan  millions  and  millions 
of  years  before  it  was  discovered  by  European 
farmers. 

Moreover,  nature  sometimes  even  goes  in  for 
deliberate  manuring.  Plants  like  buttercups 
and  daisies,  that  live  in  ordinary  meadow  soils, 
to  be  sure,  get  enough  nitrogen  and  sulphur 
and  other  such  constituents  from  the  mould 
in  which  they  are  rooted.  But  in  very  moist 


HOW    PLANTS    DRINK.  69 

and  boggy  soils  there  is  generally  ajlack_qf  these_ 
necessary  earth-given  elements  of  "protoplasm  ; 
and  natural  selection  has  therefore  favoured 
any  device  in  the  plants  which  grow  in  such 
places  for  obtaining  them  elsewhere.  This  they 
do  as  a  rule  by  catching  insects,  killing  them, 
sucking  their  juices,  and  using  them  up  as 
manure  for  manufacturing  their  own  protoplasm 
and  chlorophyll.  Our  pretty  little  English 
sundew  is  one  of  these  cruel  and  perfidious  plants 
(Fig.  10).  Its  leaves  are  round,  and  thickly 
covered  with  small  red  hairs,  which  are  rather 
bulbous  at  the  end,  and  very  sticky.  The 
bulbous  expansions,  in  point  of  fact,  are  small 
red  glands,  which  exude  a  viscid  digestive 
liquid.  When  a  small  fly  alights  on  the  leaf, 
attracted  by  the  smell  of  the  sticky  fluid,  he  is 
caught  and  held  by  its  gummy  mass  ;  the  hairs 
then  at  once  bend  over  and  clutch  him,  pouring 
out  fresh  slime  at  the  same  time,  which  very 
shortly  envelopes  and  digests  him.  In  the 
course  of  a  few  hours  the  leaf  has  sucked  the 
poor  victim's  juices,  and  used  them  up  in  the 
manufacture  of  its  own  protoplasm. 

Many  other  insect-eating  plants  exist  in  the 
marshy  soils  of  other  countries.  One  of  the 
best-known  is  the  Venus' 's  fly -trap  of  tropical 
or  subtropical  North  America.  In  this  curious 
plant  the  leaf  is  divided  into  two  portions,  one 
of  which  forms  a  jointed  snare  for  catching 
insects.  It  is  hinged  at  the  middle  ;  and  when 
a  fly  lights  upon  it,  the  two  edges  bend  over 
upon  him,  and  the  bristles  on  the  margin 
interlock  firmly.  As  long  as  the  insect  struggles 


70        THE  STORY  OF  THE  PLANTS. 

they  remain  tightly  closed ;  when  he  ceases  to 
move,  and  is  quite  dead,  they  open  once  more, 
and  set  their  trap  afresh  for  another  insect.  A 
great  many  such  carnivorous  and  insectivorous 
plants  are  now  known :  and  in  almost  every 
case  they  inhabit  places  where  the  marshy 
and  waterlogged  soil  is  markedly  wanting,  in 
ni^ogencorirpound§.  Insect- eating  leaves  are 
trms^aT Uevice  to  supply  the  plant  with  nitrogen 
by  means  of  its  foliage,  in  circumstances  where 
the  roots  prove  powerless  for  that  purpose. 

Simpler  forms  of  the  same  sort  of  habit  may 
be  seen  in  many  other  familiar  plants.  Thus 
our  English  catchflies  and  several  other  of  our 
common  weeds  have  sticky  glandular  stems, 
which  exude  a  viscid  secretion,  by  whose  aid 
they  catch  and  digest  flies.  This  is  the  begin- 
ning of  the  insect-eating  habit,  more  fully 
evolved  by  natural  selection  in  marsh-plants 
like  sundew,  and  especially  in  larger  subtropical 
types  like  the  Venus's  fly-trap.  If  you  collect 
English  wild-flowers  you  will  soon  perceive  that 
a  great  many  of  them  have  sticky  glands  on  the 
summit  of  the  stem,  near  the  flowering  heads  ; 
and  this  is  useful  to  them,  because  the  flowers 
and  seeds  are  particularly  in  want  of  nitrogenous 
matter  for  the  pollen  and  ovules  and  the  de- 
velopment of  the  seed.  In  short,  though  plants 
get  their  nitrogen  mainly  by  means  of  the  roots, 
they  often  lay  in  a  supplementary  store  by  their 
stems  and  their  foliage. 

Our  common  English  teasel  shows  us  the 
beginnings  of  another  form  of  insect-eating, 
which  is  highly  developed  in  certain  American 


HOW   PLANTS    DBINK.  71 

and  Asiatic  marsh-plants.  The  leaves  of  teasel 
grow  opposite  one  another,  joining  the  stem  at 
the  base,  so  as  to  form  between  them  a  sort  of 
cup  or  basin,  which  will  hold  water.  If  you 
look  close  into  this  water  you  will  find  that  it 
is  often  full  of  dead  midges  and  ants  ;  and  the 
plant  puts  forth  long  strings  of  living  protoplasm 
into  the  water,  which  suck  up  the  decaying 
juices  of  these  insects,  and  use  them  for  the 
manufacture  of  more  protoplasm  and  chlorophyll. 
In  this  case,  water  is  used  both  as  a  trap  and  as 
a  solvent ;  the  insects  are  first  drowned  in  the 
moat,  and  then  allowed  to  decay  and  digest 
themselves  in  it. 

Teasel,  however,  is  but  a  simple  example  of 
this  method  of  insect-catching.  Several  American 
marsh-dwellers,  collectively  known  as  pitcher- 
plants,  carry  the  same  device  a  great  deal 
further.  They  are  far  more  advanced  and 
developed  water-trap  setters.  The  Canadian 
side-saddle  plant  allures  insects  into  its  vase- 
shaped  leaves,  which  are  filled  with  sugar  and 
water.  This  is  just  the  same  plan  which  we 
ourselves  employ  to  catch  flies  when  we  trap 
them  in  a  glass  vessel  by  means  of  a  sweetened 
and  sticky  liquid.  The  pitchers  are  formed  by 
leaves  which  join  at  the  edges;  they  are  at- 
tractively coloured,  so  as  to  allure  the  flies  ;  and 
they  secrete  on  their  walls  a  honeyed  liquid, 
which  entices  the  victim  to  venture  further  and 
further  down  the  fatal  path.  But  the  inner  sides 
of  the  vase  are  set  with  stiff  down  ward -pointing 
hairs,  which  make  it  easy  to  go  on,  but  im- 
possible to  crawl  back  again.  So  the  flies  creep 


72 


THE   STOKY  OP   THE   PLANTS. 


down,  eating  away  at  the  sticky  sweet- stuff  as 
they  go,  till  they  reach  the  bottom  and  the 
hungry  water,  when  they  fall  in  by  hundreds, 


FIG.    11. AN   AUSTRALIAN    PITCHER    PLANT   WHICH 

EATS    INSECTS. 

and  are  drowned  and  digested.  I  have  found 
these  plants  often  by  the  sides  of  Canadian  bogs, 
with  a  whole  seething  mass  of  festering  and 


FIG.    12.— INSECT-EATING   PITCHERS   OF   THE   MALAYAN   NEPENTHES. 


74        THE  STOKY  OF  THK  PLANTS. 

decaying  insects  filling  up  every  one  of  their 
murderous  vases.  Other  pitcher-plants  are  found 
in  Australia  (Fig.  11). 

The  Nepenthes  of  the  Malayan  Archipelago  is 
a  still  more  remarkable  water-trap  insect-eater, 
in  which  the  pitcher  is  formed  by  a  curious  jug- 
like  prolongation  at  the  end  of  the  leaf  (Fig.  12). 
It  is  provided  with  a  lid,  and  its  rim  secretes  a 
sticky  sweet  liquid.  Insects  that  enter  the  jug 
are  prevented  from  escaping  by  strong  recurved 
hooks  ;  and  these  hooks  are  so  powerful  that  at 
times  they  have  been  known  even  to  capture 
small  birds  which  had  incautiously  entered. 
This  may  seem  curious,  but  it  is  not  odder  than 
the  fact  that  our  own  English  bladderwort,  a  water 
plant  with  pretty  yellow  flowers,  which  grows  in 
sluggish  streams,  has  submerged  bladders  that 
supply  it  with  manure,  not  only  from  water- 
beetles,  larvae,  and  other  insects,  but  also  from 
trout  and  other  young  fry  of  freshwater  fishes. 
I  may  add  that  while  the  sundew  and  other  live- 
insect  catchers  have  to  digest  their  prey, 
the  water-trap  makers  save  themselves  that 
additional  trouble  and  expense  by  macerating 
and  soaking  it  till  it  reaches  the  condition  of  a 
liquid  manure,  ready  dissolved  for  absorption, 
and  easy  to  assimilate. 

Thus  we  see  that  while  roots  are  the  chief 
organs  for  absorbing  nitrogenous  matter,  they 
are  often  supplemented  irfspecial  circumstances 
by  leaves  and  stems.  Moreover,  in  many  cases 
leaves  also  supply  the  plant  with  water.  On  the 
other  hand,  roots  often  fulfil  yet  another  function, 


HOW   PLANTS   DKINK.  75 

by  storing  up  food  for  the  plant  from  one  season 
to  another.  It  is  true  this  is  still  more  often 
done  by  underground  stems,  but  the  distinction 
between  the  two  is  very  technical,  and  I  do  not 
think  I  need  trouble  you  here  with  it.  Large 
trees  with  solid  trunks  usually  lay  by  their 
starch  and  other  valuable  materials  over  winter 
in  a  peculiar  living  layer  of  the  bark ;  and  here 
it  is  on  the  whole  fairly  free  from  danger.  Still, 
even  in  trees  the  lower  part  of  the  bark  is  often 
nibbled  by  such  animals  as  rabbits ;  and  to 
prevent  this  mischance  most  smaller  plants  bury 
their  rich  food- stuffs  underground  during  the  cold 
season.  For  whatever  will  feed  a  young  plant 
or  a  growing  shoot  will  also  just  equally  feed  an 
animal.  Hence  the  frequency  with  which  plants 
make  hoards  of  their  collected  food- stuffs  under- 
ground, for  use  next  season.  The  potato  is  a 
well-known  instance  of  such  underground  hoards ; 
the  plant  lays  by  in  what  are  technically  sub- 
terranean branches  a  supply  of  food- stuff  for 
next  season's  growth.  These  branches  are 
covered  with  undeveloped  buds,  which  the 
farmer  calls  "  eyes "  ;  and  from  each  of  these 
eyes  (if  the  potato  is  left  undisturbed,  as  nature 
meant  it  to  be)  a  branch  or  stem  will  start 
afresh  next  season.  It  will  use  up  the  starch 
and  other  foodstuffs  in  the  potato,  till  it  reaches 
the  light ;  and  there  it  will  begin  to  develop 
green  chlorophyll,  and  to  make  fresh  starch  for 
itself,  and  young  leaves  and  branches. 

An  immense  number  of  plants  thus  lay  by 
underground  stores  of  food  for  next  season's 
use.  Such  are  the  carrot,  the  beet,  and  the 


76        THE  STORY  OF  THE  PLANTS. 

turnip.  And  in  every  case  the  young  shoots 
that  spring  from  them  use  up  the  starches  and 
other  food-stuffs  at  first  exactly  as  an  animal 
would  do.  These  stores  are  often  protected 
against  animals  by  hard  coats  or  poisonous 
juices.  Many  well-known  examples  of  sub- 
terranean stores  occur  among  our  spring  garden 
flowers,  which  are  for  the  most  part  either 
bulbous  or  tuberous.  The  material  laid  by  in 
the  bulb  allows  them  to  start  flowering  early, 
while  annuals  and  other  unthrifty  plants  have 
to  wait  till  they  have  collected  enough  material 
in  the  same  year  to  flower  upon.  Hyacinths, 
tulips,  daffodils,  snowdrops,  crocuses,  and  the 
various  kinds  of  squills  and  jonquils  are  familiar 
examples  of  plants  which  lay  by  in  one  year 
material  for  the  next  year's  flowering  season. 
But  our  wild  flowers  do  the  same  thing  quite  as 
much,  though  less  obtrusively.  Our  earliest 
spring  buttercup  is  the  bulbous  buttercup,  which 
has  a  swollen  root-stock,  full  of  rich  material ; 
and  this  enables  it  to  flower  very  soon  indeed, 
while  the  fibrous  -  rooted  meadow  -  buttercup, 
which  closely  resembles  it  in  most  other  re- 
spects, has  to  wait  a  month  later,  and  then  to 
raise  a  much  taller  stem,  in  order  to  overtop  the 
summer  grasses,  which  by  that  time  have  reached 
a  considerable  height.  Still  earlier,  however,  is 
another  buttercup -like  plant,  the  lesser  celandine, 
which  has  material  laid  by  in  little  pill-like 
tubers  ;  and  these  have  given  it  its  curious  old 
English  name  of  pilewort.  Other  early  spring 
wild-flowers  are  the  wood  anemone  and  marsh- 
marigold,  with  rich  and  thick  almost  tuberous 


HOW   PLANTS    DEINK.  77 

root  stocks ;  the  bulbous  wild  hyacinth,  the 
tuberous  meadow  orchid,  and  the  common  arum, 
or  "lords  and  ladies,"  with  its  starchy  root,  very 
rich  in  food-stuffs.  Indeed,  in  every  case  where 
a  plant  flowers  very  early  in  spring,  you  may  be 
sure  the  material  for  its  flowering  was  laid  up 
by  the  plant  in  the  previous  year — that  it  is 
really  rather  a  case  of  delated  than  of  very  early 
flowering. 

This  is  especially  true  of  trees,  like  the  black- 
thorn or  the  flowering  almond,  where  the  flower- 
buds  are  usually  formed  over  winter,  and  only 
fully  developed  in  the  succeeding  spring.  The 
same  thing  happens  with  gorse ;  only  here,  a 
few  bushes  always  break  into  bloom  in  October 
or  November,  while  others  burst  spasmodically 
into  blossom  whenever  a  warm  and  sunny  spell 
occurs  in  January  or  February.  The  remaining 
bushes  are  covered  through  the  winter  with 
hairy  brown  buds,  and  burst  out  in  early  spring 
into  golden  masses  of  scented  blossom.  A  like 
arrangement  also  occurs  in  many  catkins,  which 
are  the  flowers  of  certain  trees  ;  the  catkins  of 
the  birch  and  the  alder,  for  example,  are  always 
formed  in  early  autumn,  though  they  only  break 
into  bloom  with  recurring  warmth  in  March  or 
April. 

We  have  travelled  away  so  far  from  our 
original  question  of  How  plants  drink,  that  a 
summary  of  this  chapter  is  even  more  necessary 
than  usual. 

Plants  drink  by  means  of  roots.  But  they 
take  up  by  them,  not  only  water,  which  is  their 


78         THE  STOKY  OF  THE  PLANTS. 

needful  solvent,  but  also  other  materials  urgently 
required  for  their  growth  and  development.  The 
most  important  of  these  materials  is  certainly 
j nitrogen,  which  forms  an  indispensable  com- 
\ponent  of  protoplasm  and  chlorophyll.  Where, 
however,  the  roots  do  not  supply  nitrogenous 
matter  in  sufficient  quantities,  plants  procure  it 
for  themselves  by  means  of  their  leaves  or  stems, 
and  therefore  become  insect-eating  or  flesh- 
eating.  Soils  get  exhausted  at  times  of  nitrates, 
phosphates,  and  other  necessary  materials  of 
plant-life.  The  farmer  meets  this  difficulty  by 
manuring,  and  by  rotation  of  crops.  Nature 
meets  it  by  dispersion  of  seeds.  Eoots,  however, 
have  other  functions  besides  drinking  water  and 
sucking  up  with  it  certain  dissolved  materials ; 
the  chief  of  these  other  functions  are  fixing  the 
plant  securely  in  the  ground,  and  affording  a 
safe  place  of  winter  storage  for  starches  and 
other  surplus  food-stuffs.  Many  plants  die  down 
almost  entirely,  above  ground,  in  winter, 
and  keep  their  raw  material  in  underground 
reservoirs,  most  of  which  are  stem-like  rather 
than  root-like.  Animals,  however,  find  out  these 
subterranean  reserves,  and  prey  upon  them ; 
hence  the  plants  often  secure  their  hoard  by 
nauseous  tastes  or  other  protective  devices. 

CHAPTEE  VI. 

HOW   PLANTS    MAKRY. 

WE   next  come   to  what  is  perhaps   the   most 
fascinating  chapter  of  all  in  the  life-history  of 


HOW   PLANTS   MABKY.  79 

plants — the  chapter  which  tells  us  how  they 
marry  and  are  given  in  marriage. 

In  order  that  you  may  fully  understand  this 
curious  and  delightful  subject,  however,  I  shall 
have  to  begin  by  telling  you  a  few  preliminary 
points  less  interesting  in  themselves,  and,  I  fear, 
at  times  not  a  little  troublesome. 

Flowers  are  the  husbands  and  wives  of  plants. 
And  in  some 
plants  the  sexes 
are  as  fully  sepa- 
rated as  in  birds 
or  beasts;  when 
once  you  know 
them,  you  can 
distinguish  at 
sight  a  male 
from  a  female 

flower  as  readily  ^ 

as  you  can  dis-   a    ^PP  ^  A 

tinguish  a   bull  FIG-  13. —A,  MALE,  &  B,  FEMALE  FLOWER 

from    a     nnw     nr        OF  A  SEDGE»   M™H  MAGNIFIED.       The 

om  a  cow,  or     gexes  ftre  here      ite   distinct  and 
a  peacock  irom      unlike. 
a  peahen  (Fig. 

13).  But  in  other  cases  the  sexes  are  muddled 
up  in  the  same  blossom  or  on  the  same  plant  in 
a  way  that  makes  it  rather  difficult  to  understand 
their  true  nature  without  a  little  pains  and  some 
close  attention. 

So  we  must  go  back  a  bit  for  light  to  the 
lower  plants.  Here  we  find  no  flowers  at  all, 
and  in  the  very  lowest  cases  of  any  nothing  in 
the  least  resembling  a  blossom.  Very  simple 
plants,  in  fact,  have  two  ways  of  reproducing. 


THE    STORY   OF    THE    PLANTS. 


The  earliest  way  is,  when  a  single  cell  divides  in 
the  middle,  to  form  two  others;  a  somewhat  less 
primitive  way  is  when  a  single  cell  breaks  sud- 
denly up,  and  produces  from  itself  a  whole 
swarm  of  young  ones.  In  both  these  ways, 
however,  there  is  no  trace  of  sex ;  only  one 
single  cell  is  concerned  in  the  process ;  the 
plants  have  a  mother,  perhaps,  but  certainly  not 
a  father. 

The  thread-like  pond-weeds,  however,  which 
are  slightly  higher  plants  in  the 
scale  of    being   than   the   single- 
celled  floating  types,  show  us  the 
first  beginnings  of  something  like 
plant-marriage.      These    hair-like 
little  weeds  consist  each  of  a  single 
thread  or  string  of  cells,  placed 
end  on  end  together,  like  beads 
or  pearls  in  a  necklet,   and  con- 
taining green   chlorophyll.      You 
can  find  them  in  almost  any  stag- 
nant pond  in  spring,  where  they 
no.  14.— BEGIN-  cling  to  the  side  in  soft  greenish 
NINGS  OF  SEX  moss-like  or  velvety  masses.    But 
IN  A  POND  WEED,  ft  vou  €xamine  one  slimy  string 
MAGNIFIED™01*  under    a    microscope,    you    will 
see    a    curious   thing   often   hap- 
pening between  the  threads  of  two  such  hair-like 
plants.     As  they  grow  side  by  side,  two  of  the 
strings  will   sometimes  range   themselves   just 
parallel  to  one  another,  with  their  cells  facing 
(Fig.    14).      Then   each   opposite  pair  of  cells 
begins  to  bulge  a  little  at  the  point  where  they 
nearly  touch  (a  and  b  in  the  figure),  till  at  last 


\ 


HOW   PLANTS   MABKY.  81 

they  join  and  coalesce  with  one  another  (c  and  d 
in  the  figure).  The  contents  of  one  cell  pass 
into  another  (at  e),  and  the  two  form  a  sort  of 
egg  (/),  which  lies  quiet  for  a  while,  and  then 
buds  out  into  a  new  thread  or  hair-like  plant  by 
division.  In  this  strange  process  we  have  the 
beginning  of  sex — the  first  hint  of  plant  and 
animal  marriages. 

What  is  the  meaning  and  good  of  it?  Why  do 
the  plants  act  thus  ?  That  question  we  don't  yet 
quite  understand,  perhaps ;  but  this  seems  to  be 
in  part  at  least  its  reason.  Protoplasm  requires 
to  be  kept,  as  it  were,  perpetually  young  and  ever 
fresh ;  it  cannot  afford  to  lose  its  elasticity  and 
its  plasticity.  If  it  does,  it  grows  old  in  time 
and  dies.  To  prevent  this  misfortune,  and  the 
death  of  all  things,  plants  and  animals  have 
invented  all  sorts  of  curious  expedients;  for 
example,  the  protoplasm  of  a  living  cell  some- 
times breaks  out  of  the  cell- wall,  and  undergoes 
a  process  which  is  called  "  rejuvenescence,"  or 
growing  young  again.  It  lies  quiet  for  awhile  in 
its  free  condition,  and  then  begins  to  build  up  a 
new  wall  afresh  for  itself.  It  seems  by  the 
process  of  breaking  out  to  have  gained  for  itself 
a  new  lease  of  life,  as  we  ourselves  often  do  by 
a  trip  abroad  or  change  of  scene  and  air  and 
occupation.  However  this  may  be,  it  is  certain 
at  least  that  the  union  of  two  cells  often  produces 
a  fresher,  stronger,  and  more  vigorous  young 
one  than  can  be  produced  by  mere  division  of  a 
single  cell.  In  some  way  or  other,  when  a 
plant  or  animal  reaches  maturity,  and  arrives 
at  the  limit  of  its  own  growth,  it  produces 
ft 


82         THE  STOEY  OF  THE  PLANTS 

stronger  and  livelier  young  by  so  combining 
with  another  of  its  own  species. 

In  the  thread-like  pond-weeds  the  two  uniting 
cells  are  practically  similar.  They  are  not  dis- 
tinguished as  male  and  female.  Neither  of  them 
is  larger  or  smaller  than  the  other;  neither  of 
them  is  more  active  or  more  vigorous  than  its 
consort.  But  in  the  higher  plants  a  marked 
difference  invariably  exists  between  the  two  cells 
that  join  to  form  the  new  individual — a  difference 
of  kind ;  we  have  sex  now  appearing.  One  of 
the  cells  is  smaller,  and  more  active ;  it  is  called 
a  male  cell  or  pollen  cell.  The  other  is  larger, 
richer,  and  more  passive ;  it  is  called  a  female 
cell,  or  ovule — that  is  to  say  in  plain  English,  a 
little  egg.  Now  the  nature  of  the  ovule  is  such 
that  it  cannot  grow  out  into  a  seed  or  young 
plant  till  it  has  been  united  with  and  fertilised 
by  the  smaller  but  more  active  and  lively  pollen- 
cell. 

Separate  organs  in  the  higher  plants  always 
produce  the  pollen-grain  and  the  ovule.  These 
organs  are  known  as  stamens  and  pistils  (Fig. 
15).  They  are  really  separate  individuals,  or 
males  and  females.  The  stamen  is  the  father 
of  the  seed,  so  to  speak,  and  the  pistil  its  mother. 

This  is  a  hard  saying,  I  know ;  and,  in  order 
that  you  may  understand  it,  I  must  begin  by 
telling  you  another  point  about  the  plant  which 
I  have  hitherto  to  some  extent  studiously  con- 
cealed from  you.  It  is  this — each  higher  plant 
is  not  so  much  a  single  individual  as  a  commu- 
nity or  colony. 

A  hive  of  bees  will  help  you  to  understand 


HOW   PLANTS   MARKY.  83 

this  difficult  paradox.  I  know  it  is  difficult; 
but,  if  only  you  will  face  it,  it  will  throw  floods 
of  light  in  due  time  on  parts  of  our  subject  we 
must  consider  hereafter.  So  let  us  look  at  it 
close.  A  hive  is  a  community.  It  consists  for 
the  most  part  of  workers,  who  are  practically 
neither  male  nor  female.  They  are  neuters,  as 
we  say ;  and  their  main  work  is  to  find  food  for 
the  whole  hive, 
including  them- 
selves and  the 
grubs  or  larvae 
which  are  the 
young  of  the 
species.  But,  in 
addition  to  these 
workers,  the  hive 
has  a  queen,  who 

i  tne  only  per-  FIG>  ^ — A  FLOWER,  WITH  ITS  PETALS 
feet  female,  or  REMOVED.  Outside  are  five  stamens, 
mother,  and  who  which  produce  pollen  :  in  the  centre 
lavs  the  eggs  *s  *ne  P*8^*  which  contains  the 
from  which  the  ovules  or  y°ung  seeds' 
larvae  are  produced ;  and  it  has  also  several 
drones,  who  are  the  males  of  the  community,  and 
fathers  of  the  larvae.  Thus  we  have  a  colony  or 
city,  as  it  were,  consisting  of  a  few  males,  a 
single  female,  and  a  whole  body  of  worker  or 
feeder  neuters. 

Now,  a  higher  plant,  like  a  cherry-tree  (to 
take  a  particular  example),  is  just  such  a  colony 
or  joint  community.  The  leaves,  each  of  which 
is  a  distinct  and  almost  self-supporting  indi- 
vidual, are  its  workers  and  feeders.  Like  the 


84        THE  STOEY  OF  THE  PLANTS. 

worker  bees,  too,  the  leaves  are  neuters — 
neither  true  males  nor  true  females.  They  feed 
&nd  lay  by,  and  from  them  new  leaves  are 
'continually  produced  in  the  buds  and  at  the 
lends  of  branches.  This  is  called  the  sexless 
/method  of  reproduction,  and  it  is  essentially 
j  similar  to  the  way  in  which  the  single-celled 
1  plant  or  the  simple  animal  divides  itself  sexlessly 
j^into  two  or  more  little  plantlets  or  animals. 
But,  in  addition  to  this  sexless  way,  the  plant 
also  at  certain  times  produces  other  sorts  of 
leaves  which  are  sexual  individuals,  and  these 
we  call,  in  the  lump,  flowers.  But  flowers  are 
not  all  alike  throughout.  They  consist  of  certain 
male  individuals,  the  stamens,  which  answer  to 
the  drones,  and  of  certain  female  individuals,  the 
pistils  or  carpels,  which  answer  to  the  queen  or 
mother  bee,  and  produce  the  ovules  or  little  eggs 
of  the  family.  A  cherry-tree  is  thus  a  plant- 
hive  or  colony,  consisting  for  the  most  part  of 
workers  or  leaves,  but  also  at  certain  times  of 
year  producing  male  and  female  members,  whose 
business  it  is  to  found  fresh  swarms,  as  it  were 
— to  produce  the  seeds  which  are  the  basis  and 
foundation  of  new  colonies. 

There  is  of  course  one  great  difference  between 
a  hive  and  a  plant,  and  that  is  that  in  the  hive 
the  individuals  are  separate  and  distinct,  while 
in  the  plant  they  are  combined  on  a  single  stem, 
which  serves  to  join  them.  In  this  respect 
plants  are  more  like  a  branch  of  coral,  which 
consists  of  a  number  of  distinct  animals  or 
polypes,  united  by  a  core  of  stony  material,  and 
a  living  mass  of  connecting  matter.  Yet  the 


HOW   PLANTS   MAEEY.  85 

difference  between  the  leaves  and  the  bees  is\ 
not  so  great  as  at  first  sight  appears ;  for  though) 
each  leaf  does  not  as  a  rule  live  separately,  it  is'; 
often  capable  of  doing  so  if  occasion  arises.  A 
single  leaf  of  stonecrop,  separated  from  the' 
parent  plant,  will  root  itself  and  grow  into  a 
fresh  colony ;  and  in  some  plants,  like  begonias, 
a  single  fragment  of  a  leaf,  if  placed  on  wet  soil, 
is  capable  of  growing  out  into  a  new  individual. 
In  other  cases  small  leaves  drop  off  from  a  plant 
as  bulbils,  and  root  and  grow  ;  while  in  others, 
again,  young  plants  sprout  out  from  the  edges 
of  old  leaves  to  form  new  colonies.  In  short, 
though  the  leaf  is  not  usually  a  distinct  plant,-* 
it  sometimes  is,  and  it  can  often  become  one ;  itfc 
frequently  gives  rise  in  a  sexless  way  to  fresh  v 
plant  colonies.  A  graver  difficulty  is  this :  the 
plant  differs  from  the  hive  in  being  more  closely 
connected  and  subordinated  in  its  parts — the 
stem  and  root  (which  bind  and  unite  it),  bringing 
water  and  nitrogenous  matter,  while  the  leaves 
elaborate  the  starch  and  protoplasm  and  other 
chief  food-stuffs.  Even  this  difference,  however, 
is  less  grave  than  it  seems,  if  we  remember  that 
the  queen  bee  and  the  larvae  are  similarly 
dependent  upon  the  workers  for  food  and 
protection.  A  plant,  in  short,  is  a  colony  of 
various  forms  of  leaves,  very  closely  united 
together  for  mutual  service,  and  very  much 
specialised  in  various  way's  among  themselves 
for  particular  functions. 

And  now  we  are  in  a  position  to  know  what 
work  the  flower  has  to  do  in  the  community. 


86        THE  STORY  OF  THE  PLANTS. 

It  is  a  collection  of  special  and  peculiar  leaves, 
told'  off  to  act  as  fathers  and  mothers  to  the 
seeds,  whence  are  to  be  born  future  plant 
swarms  or  future  colonies. 

A  flower,  in  its  simplest  form,  consists  of  a 
single  stamen  or  a  single  carpel — that  is  to  say, 
of  one  leaf  or  leaf -like  organ,  told  off  for  the 
production  of  pollen ;  or  of  one  leaf  or  leaf -like 
organ,  told  off  for  the  production  of  young  seeds 
or  ovules.  Flowers  as  simple  as  that  do  actually 
occur,  but  more  often  a  flower  is  much  more 
complex,  consisting  of  several  stamens  and 
several  carpels,  as  well  as  of  other  protective 
or  attractive  leaves,  often  highly  coloured  and 
conspicuous,  which  surround  or  envelop  these 
essential  organs. 

The  most  familiar  flowers,  as  we  actually 
know  them,  are  of  this  last  more  complex  type ; 
each  comprises  in  itself  several  male  and  several 
female  individuals.  The  male  individuals  are 
stamens,  each  of  which  generally  consists  of  two 
little  pollen-bags,  called  the  anthers,  and  a  rather 
slender  stalk  or  support,  known  as  the  filament. 
The  female  individuals  are  carpels,  each  of  which 
generally  consists  of  a  sort  of  sack  or  folded  leaf, 
enclosing  one  or  more  tiny  seeds  or  ovules. 

But  that  is  not  at  all  what  you  mean  by  a 
flower !  No ;  certainly  not ;  and  half  the  flowers 
you  meet  in  a  morning's  walk  you  do  not  take 
for  flowers  at  all,  and  pass  by  unrecognised. 
Such  are  the  green  or  inconspicuous  blossoms 
of  the  grasses,  nettles,  oaks,  and  sedges,  as  well 
as  those  of  the  pines,  the  dog's  mercury,  the 
spurge,  and  the  hazel.  What  you  mean  most 


HOW  PLANTS   MABBY. 


87 


by  a  flower  is  a  mass  of  red  or  yellow  petals, 
conspicuously  arranged  about  the  true  floral 
organs.  The  petals  form,  in  point  of  fact,  the 
popular  notion  of  a  flower— though  from  the 
point  of  view  of  science  they  are  comparatively  un- 
important, and  are 
commonly  spoken 
of  (with  the  calyx) 
as  "the  floral  en- 
velopes." It  is  the 
stamens  and  pistils 
(or  carpels)  that  are 
the  true  flowers ; 
they  do  the  mass  of 
the  real  work ;  and 
an  enormous  num- 
ber of  flowers  pos- 
sess these  organs 
alone,  without  any 
conspicuous  petals 
or  other  coloured 
surfaces. 

However,  if  you 
take  a  pretty  garden 
flower  (say  a  scarlet 
geranium)  as  a  typi- 
cal   example,    and 
begin  to  examine  it 
from  the  centre  out-   FIG.  16.— GRAINS  OF  POLLEN,  VERY 
ward  (which  is  the       MUCH  MAGNIFIED,  SENDING  OUT 
truest     way),     you       ™LLE»-TUBEB. 
will  find  it  consists  of  the  following  parts,  in  the 
following  order : — 

In  the  very  centre  of  all  comes  the  pistil, 


88        THE  STOEY  OF  THE  PLANTS. 

consisting  of  one  or  more  carpels,  and  con- 
taining the  embryo  seeds  or  ovules  (see  Fig.  15). 
Outside  this  part,  and  next  in  order,  come  the 
stamens,  which  are  most  often  three  or  six  in 
one  great  group  of  flowering  plants  (the  lilies), 
and  five,  ten,  or  more  in  the  other  (the  roses 
and  buttercups).  The  stamens  produce  grains 
of  pollen,  which  somehow  or  other,  either  by 
means  of  the  wind,  or  of  insects,  or  of  move- 
ments on  the  part  of  the  plant  itself,  are  sooner 
or  later  applied  to  the  sensitive  surface  or  stigma 
of  the  pistil.  As  soon  as  a  pollen-grain  reaches 
the  surface  of  the  stigma,  it  is  held  there  by  a 
sticky  secretion,  and  instantly  begins  to  send 
out  what  is  called  a  pollen- tube  (Fig.  16).  This 
pollen- tube  makes  its  way  down  the  long  stem 
or  style  which  joins  the  stigma  to  the  ovary,  and 
there  comes  in  contact  with  the  undeveloped 
ovules.  The  ovules  would  not  swell  and  grow 
into  seeds  of  themselves ;  but  the  moment  the 
pollen-tube  reaches  them,  they  quicken  into  life, 
and  begin  to  develop  into  fertile  seeds.  Unfer- 
tilised ovules  wither  away  or  come  to  nothing, 
but  fertilisation  by  pollen  makes  them  develop 
at  once  into  new  plant  colonies. 

Outside  these  essential  organs,  as  botanists 
call  them,  however,  come,  in  handsome  garden 
flowers,  two  other  sets  of  organs,  more  leaf-like 
in  appearance,  but  often  brightly  or  conspicu- 
ously coloured.  The  first  of  these  sets  of  organs, 
going  still  from  within  outward,  is  called  the 
petals,  or,  collectively,  the  corolla.  Sometimes, 
as  in  the  dog-rose  or  the  buttercup,  the  corolla 
consists  of  five  separate  petals;  sometimes,  as 


HOW   PLANTS   MABRY. 


89 


in  the  harebell  and  the  gentian,  it  has  five 
points,  or  lobes,  unit  it  at  the  base  into  a  single 
piece  (Fig.  17).  Last  of  all,  outside  the  corolla 
again  comes  another  row  or  layer,  called  the 
calyx,  which  sometimes  consists  of  five  separate 
leaves  or  sepals,  as  in  the  dog-rose  and  the  butter- 
cup, but  sometimes  has  five  points,  welded  at 
the  base  into  one  piece,  as  in  red  campion  and 


FIG.    17. — FLOWER    OP   A    SHRUBBERY   PLANT,    WEIGELIA, 
WITH     THE     PETALS     UNITED     INTO     SINGLE     COROLLA. 

I.  Entire  flower.  II.  The  same,  with  part  of  the 
corolla  cut  away.  III.  and  IV.  A  stamen,  fe, 
calyx ;  b,  corolla ;  s,  stamen  ;  a,  anther  of  the 
stamen  ;  g  and  ??,  parts  of  the  pistil. 

convolvulus.  It  is  these  last  comparatively 
unessential  but  very  conspicuous  parts  that 
most  people  think  of  when  they  say  "  a  flower.'1 

What  is  their  use  ?  Well,  they  are  not  essen- 
tial, like  the  pistil  and  stamens,  because  many 
flowers,  perhaps,  even  most  flowers,  do  without 


90        THE  STOKY  OF  THE  PLANTS. 

them  altogether.  But  they  are  very  useful  for 
all  that,  as  we  may  easily  guess,  because  they 
are  found  in  almost  all  the  most  advanced  and 
developed  flowers.  The  use  of  the  corolla,  with 
its  brilliantly  coloured  petals,  is  to  attract  insects 
to  the  flowers  and  induce  them  to  carry  pollen 
from  plant  to  plant.  That  is  why  they  are 
painted  red  and  blue  and  yellow ;  they  are  there 
as  advertisements  to  tell  the  bee  or  butterfly, 
"Here 'you  can  get  good  honey."  The  use  of 
the  calyx  is  usually  to  cover  up  the  flower  in  the 
bud,  to  keep  it  safe  from  cold,  and  to  protect  it 
from  the  attacks  of  insect  enemies,  who  often 
try  to  break  through  and  steal  the  half-developed 
pollen  in  the  bags  of  the  stamens  before  it  is 
ripe  and  ready  for  fertilising.  These  are  the 
chief  uses  of  the  calyx  or  outer  cup  of  the 
flower ;  but,  as  we  shall  see  hereafter,  it  serves 
many  other  useful  purposes  from  time  to  time 
in  various  kinds  of  flowers.  In  the  fuschia,  for 
example,  it  is  quite  as  brilliantly  coloured  as  the 
petals  of  the  corolla,  and  supplements  them  in 
the  work  of  attracting  insects.  In  the  winter 
cherry  or  Cape  gooseberry  it  forms  a  brilliant 
outer  envelope  or  covering  for  the  fruit,  which 
the  French  call  "cerise  en  chemise"  or  "cherry 
in  its  nightdress."  Other  uses  of  both  calyx 
and  corolla  will  come  out  by  and  by,  as  we 
proceed  to  examine  individual  instances. 

"  But  why,"  you  may  ask,  "  do  the  plants 
want  to  get  pollen  carried  from  plant  to  plant  ? 
Why  can't  each' flower  fertilise  itself  by  letting  its 
pollen  fall  upon  its  own  pistil  ?  "  Well,  the  ques- 
tion is  a  natural  one ;  and,  indeed,  many  flowers 


HOW   PLANTS   MARKY.  Ol 

do  actually  so  fertilise  themselves  with  their 
own  pollen.  But  such  flowers  are  almost  always 
poor  and  degenerate  kinds,  the  unsuccessful  in 
the  race,  the  outcasts  and  street  arabs  of  plant 
civilisation.  All  the  higher,  nobler,  and  more  • 
dominant  plants — the  plants  that  have  carved 
out  for  themselves  great  careers  in  the  world, 
and  that  occupy  the  best  posts  in  nature — have 
invented  some  mode  or  other  of  cross- fertilisa- 
tion, as  it  is  called,  that  is  to  say  some  plan  by 
which  the  pollen  of  one  plant  or  flower  fertilises 
the  pistil  of  another. 

What  does  this  mean?  Well,  regarding  the 
plant  as  a  colony,  you  will  see  at  once  that  the 
stamens  and  pistil  of  the  same  blossom  stand  to 
one  another  somewhat  in  the  relation  of  brothers  / 
and  sisters,  while  those  of  different  flowers  on  the  I 
same  plant  may  be  regarded  at  least  in  the  light  j 
of  first  cousins.  Now  the  very  same  thing  that 
makes  sex  and  marriage  desirable,  makes  close 
intermarriage  of  blood  relations  undesirable. 
"  Marrying  in  and  in,"  as  it  is  called,  tends  to 
produce  weak  and  feeble  offspring,  while  "an 
infusion  of  fresh  blood"  tends  to  make  both 
plants  and  animals  stronger  and  more  vigorous. 
Hence,  if  any  habit  chanced  to  arise  in  plants 
which  favoured  or  rendered  easier  such  cross- 
fertilisation,  it  would  result  in  stronger  and  more 
vigorous  young,  and  would  therefore  be  fixed  by 
natural  selection.  The  actual  consequence  is 
that  in  the  world  of  plants,  as  we  see  it  to-day, 
every  great  dominant  or  successful  race  has 
invented  some  means  of  cross-fertilisation,  either 
by  the  agency  of  wind  or  of  insects,  while  only 


92        THE  STOKY  OF  THE  PLANTS. 

ihe  miserable  riff-raff  and  outcasts  of  plant-life 
still  adhere  to  the  old  and  bad  method  of  fertili- 
sation by  means  of  the  pollen  of  their  own 
flowers. 

We  are  now  in  a  position  to  understand  the 
main  principles  which  govern  the  marriage  cus- 
toms of  plants ;  we  will  proceed  in  the  next 
chapter  to  consider  in  detail  how  these  prin- 
ciples work  out  in  particular  instances.  But 
first  we  must  sum  up  what  we  have  learnt  in 
this  chapter, 

Plants  marry  and  are  given  in  marriage.  The 
-  very  lowest  plants,  indeed,  are  sexless,  but  in 
:  the  higher  there  are  well-marked  distinctions  of 
male  and  female.  An  intermediate  stage  exists 
in  certain  thread-like  pond- weeds,  where  mar- 
Triage  or  intermixture  takes  place  between  two 
/  adjacent  cells,  neither  of  which  is  male  or  female. 
The  higher  plants,  however,  are  really  com- 
munities or  colonies,  of  which  the  leaves  are 
the  workers,  and  the  various  parts  of  the  flower 
the  males  and  females.  The  central  part  of  the 
flower,  known  as  the  pistil,  is  the  female  indi- 
vidual ;  it  produces  ovules,  or  young  seeds, 
which,  however,  cannot  grow  and  swell  without 
the  quickening  aid  of  pollen.  The  next  row  in 
the  flower,  known  as  the  stamens,  contains  the 
male  individuals ;  they  produce  pollen,  which 
lights  on  the  sensitive  surface  of  the  pistil,  sends 
out  tubes  of  very  active  living  matter,  and 
quickens  or  impregnates  the  ovules  in  the  pistil. 
Besides  these  necessary  organs  flowers  have 
often  two  other  sets  of  parts.  The  corolla, 


VARIOUS   MARRIAGE   CUSTOMS.  93 

which  is  made  up  of  petals,  united  or  distinct, 
is  usually  brightly  coloured,  and  acts  as  an 
advertisement  or  allurement  to  the  insects ;  it 
occurs  chiefly  in  insect  -  fertilised  flowers,  and 
generally  implies  the  presence  of  honey.  The 
calyx  or  outer  cup,  which  is  made  up  of  sepals, 
distinct  or  united,  acts  mainly  as  a  protective 
covering.  Plants  can  fertilise  themselves  if 
nec.egs.ary,  but  in  all  the  highest  and  most 
successful  plants  some  form  or  other  of  £ros§b. 
fertilisation  has  become  almost  universal.  Self- 
f ertilisation  goes  down  the  hill ;  cross-fertilisation 
is  the  road  to  success  and  vigour. 


CHAPTEB  VII. 

VARIOUS   MARRIAGE   CUSTOMS. 

THE  simplest  and  earliest  flowering  plants  had 
probably    only    three    sets    of    organs — leaves,  ^ 
stamens,    and  pistils  —  workers,    males,    and. 
females.     Their  flowers  consisted  at  best  of  the*' 
necessary  organs,  enclosed,  perhaps,  in   a  few 
protective  sheathing  leaves,  rather  smaller  than 
the  rest,    the  forerunners   of    a   calyx.      How, 
then,  did  modern  flowers  come  to  get  at   last 
their  brilliant  corollas? 

We  must  remember  that  anything  which  made 
flying  insects  visit  plants  would  be  of  use  to  the 
flowers,  as  promoting  cross-fertilisation.  Now, 
as  far  as  we  can  see  at  present,  before  flying 
insects  were  evolved  in  the  animal  world,  there 
could  have  been  no  such  things  as  bright-hued 


94:  THE    STORY   OF   THE   PLANTS. 

blossoms  in  the  vegetable  kingdom.  But  insects 
must  very  early  have  gone  about  eating  pollen 
on  plants,  as  they  do  to  this  day  in  many  in- 
stances ;  and  though  in  itself  this  would  be  a 
loss  to  the  plant,  yet  plants  have  often  found  it 
well  worth  their  while  to  pay  blackmail  to  in- 
sects in  return  for  some  benefit  incidentally 
conferred  upon  them.  Again,  as  the  insects  flew 
from  plant  to  plant,  they  would  be  sure  to  carry 
pollen  on  their  heads  and  legs ;  and  they  would 
rub  off  this  pollen  on  the  sticky  stigma  of  the 
next  flower  they  visited,  which  would  make 
them  on  the  whole  useful  and  profitable  visitors. 
So  the  plants,  finding  the  good  cross-fertilisation 
did  them,  began  in  time  to  bribe  the  insects  by 
producing  honey  in  the  neighbourhood  of  their 
pistils  and  stamens,  and  also  to  attract  their 
eyes  from  afar  by  means  of  those  alluring  and 
brilliantly  -  coloured  advertisements  which  we 
call  petals. 

I  don't  mean,  of  course,  that  the  plants  knew 
they  were  doing  all  this  ;  they  were  unconscious 
agents.  Whenever  any  variation  in  the  right 
direction  occurred  by  chance,  natural  selection 
immediately  favoured  it,  so  that  in  the  end  it 
comes  almost  to  the  same  thing  as  if  the  plant 
deliberately  intended  to  allure  the  insect;  and  for 
brevity's  sake  I  shall  often  so  word  things. 

How  did  the  plant  first  come  to  develop  such 
bright- hued  petals  ?  I  think  in  this  way.  Most 
early  types  of  flowers  have  a  great  many  stamens 
apiece,  and  these  stamens  are  so  extremely 
numerous  that  one  or  two  of  them  might  readily 
be  spared  for  any  other  purpose  the  plant  found 


VARIOUS   MARRIAGE   CUSTOMS.  95 

useful.  Gradually,  as  botanists  £  imagine,  an 
outer  row  of  these  stamens  got  flattened  out 
into  a  form  like  foliage  leaves,  only  without  any 
ribs  or  veins  to  speak  of,  and  developed  bright 
colours  to  attract  the  insects.  Such  a  flattened 
and  gaily-decked  stamen,  with  no  pollen-bearing 
bag,  is  what  we  call  a  petal.  It  is  usually  ex- 
panded, thin,  and  spongy,  and  it  is  admirably 
adapted  for  the  display  of  bright  colours. 

We  have  still  certain  flowers  among  us  which 
show  us  pretty  clearly  how  this  change  took  place. 
The  common  white  water-lily  is  one  of  them. 
In  the  centre  of  the  blossom,  in  that  beautiful 
plant,  we  find  a  large  pistil  and  numerous  sta- 
mens of  the  ordinary  sort,  with  round  stalks  or 
filaments,  and  yellow  pollen-bags  hanging  out  at 
their  ends.  Then,  as  we  move  outward,  we 
find  the  filaments  or  stalks  growing  flatter  and 
broader,  and  the  pollen-bags  gradually  less  and 
less  perfect.  Next  we  come  to  a  few  very  flat  and 
broad  stamens,  looking  just  like  petals,  but  with 
two  empty  pollen-bags,  or  sometimes  only  one, 
stuck  awkwardly  on  their  edges.  Last  of  all  we 
arrive  at  true  petals  without  a  trace  in  any 
way  of  pollen-bags.  I  believe  the  water-lily 
preserves  for  us  still  some  memory  of  the  plan 
by  which  petals  were  first  invented.  Such  relics 
of  old  conditions  are  common  both  in  plants  and 
animals ;  they  help  us  greatly  to  reconstruct  the 
history  of  the  path  by  which  the  various  kinds 
have  reached  their  present  perfection. 

Even  in  our  own  day,  in  plants  where  stamens 
are  numerous,  they  often  tend  to  develop  into 
petals,  especially  when  growing  in  very  rich 


96        THE  STOKY  OF  THE  PLANTS. 

soil,  or  under  cultivation.     This  is  what  we  call 

"  doubling  "  a  flower.     In  the  double  rose,  for 

example,  the  extra  petals  are  produced  from  the 

stamens   of   the  interior,  and  if  you  examine 

1  them  closely  you  will  see  that  they  often  show 

•  every  possible  gradation  and  intermediate  stage, 

I  from  the  perfect  stamen   to  the  perfect  petal. 

The  same  thing  readily  happens  with  buttercups, 

poppies,  and  many  other  flowers.     We  may  take 

it  for  granted,  then,  that  petals  are,  in  essence, 

a   single  outer  row   of   stamens,  flattened  and 

coloured,  and  set  apart  by  the  plant  to  advertise 

its  honey  to  insects,  and  so  induce  them  to  visit 

and  fertilise  it. 

In  the  largest  and  most  familiar  group  of 
flowering  plants,  to  which  almost  all  the  best- 
known  kinds  belong,  the  original  number  of 
petals  seems  to  have  been  five  ;  and  we  will  take 
this  number  as  regular  for  the  present,  explain- 
ing separately  those  cases  where  it  is  exceeded 
or  diminished.  The  common  ancestor  of  all 
these  plants,  we  may  conclude,  had  all  its  parts 
f  in  rows  of  five.  Thus  it  had  five,  ten,  or  fifteen 
'  carpels  in  its  pistil — that  is  to  say,  one,  two,  or 
'three  rows  of  five  carpels  each;  it  had  five,  ten, 
or  fifteen  stamens,  it  had  five  or  ten  petals,  and 
it  had  a  calyx,  outside  all,  of  five  sepals.  We 
will  now  proceed  to  examine  in  detail  some  of 
the  many  curious  marriage  customs  which  have 
arisen  among  the  group  of  plants  that  started 
with  this  ground -plan. 

One  great  family  of  plants  which  early  divided 
itself  from  this  great  central  stock  is  the  family 


VAEIOUS  MAKBIAGE  CUSTOMS.        97 

of  the  buttercups.  Our  common  English  bulbous 
buttercup  is  one  of  its  best-known  members.  It 
is  yellow  in  colour,  a  point  which  is  common  to 
most  Dearly  and  simple  flowers,  because  the 
stamens  are  generally  yellow,  and  when  they 
developed  into  petals  they  naturally  retained  at 
first  their  original  colouring.  Only  later  and  for 
various  special  reasons  did  certain  higher  flowers 
come  by  degrees  to  be  white,  pink,  red,  blue, 
purple,  or  variegated.  There  is  some  reason  to 
believe,  indeed,  that  the  various  other  colours 
were  developed  one  after  the  other  in  the  order  ' 
here  named,  and  to  the  present  day  all  the 
simplest  families  of  flowers  remain  chiefly 
yelSw,  as  do  the  simpler  and  earlier  members 
of  more  advanced  families. 

The  common  bulbous  buttercup  is  thus  pre- 
vailingly yellow,  because  it  is  an  early  and 
simple  type  of  flowTer.  It  consists  of  four  dis- 
tinct and  successive  layers,  or  whorls  of  organs. 
Outside  all  comes  a  calyx  of  five  sepals,  which 
cover  the  flower  in  the  bud,  but  are  hardly 
noticeable  in  the  open  blossom.  They  also 
serve  to  keep  off  ants  and  other  creeping  in- 
sects, for  which  purpose  they  are  turned  back 
on  the  stem,  and  are  covered  with  small  hairs. 
"  But  I  thought  the  plant  wanted  to  attract 
insects,"  you  will  say.  Yes,  the  right  kind  of 
insects,  the  flying  types,  which  go  from  one 
flower  to  another  of  the  same  sort,  and  so  pro- 
mote due  fertilisation.  Flying  insects,  attracted 
by  colour  and  shape  of  petals,  keep  tojQAejDrajad- 
of  honey  at  a  time  ;  they  never  mix  their  liquors. 
But  ants  are  drawn  on  by  the  smell  of  honey 
7 


98         THE  STORY  OF  THE  PLANTS. 

only ;  they  crawl  up  one  stem  after  another 
indiscriminately,  and  steal  the  nectar  which  the 
plant  intends  for  its  regular  winged  visitors. 
Even  if  they  do  occasionally  fertilise  a  flower, 
it  will  probably  be  with  pollen  of  another  kind, 
so  that  the  result  will  be,  not  a  perfect  plant,  but 
a  miserable  hybrid,  ill  adapted  for  any  condi- 
tions. Hence  plants  usually  possess  advanced 
devices  for  keeping  off  ants  and  other  climbing 
thieves  from  their  precious  honey.  Hairs  on 
the  stalk  and  calyx  are  enough  to  secure  this 
object  in  the  meadow  buttercup,  which  has  a  tall 
stem,  and  therefore  is  not  so  easily  climbed ; 
for  the  hairs,  small  as  they  look  to  us,  prove  to 
the  ant  a  perfect  forest  of  underwood.  But  in 
the  early  bulbous  buttercup,  which  has  a  shorter 
stem,  and  the  smell  of  whose  honey  is  therefore 
more  alluring  to  the  groundling  ant,  this  device 
is  not  alone  sufficient ;  so  the  calyx  on  opening 
turns  down  its  separate  sepals  close  against  the 
stem  in  such  a  way  as  to  form  a  sort  of  lobster- 
pot,  out  of  which  the  creeping  insect  can  never 
extricate  himself. 

Inside  the  calyx-layer  of  five  sepals  comes 
next  the  corolla-layer  of  five  petals.  These 
petals,  as  we  saw,  are  the  attractive  business 
advertisement  of  the  flower ;  they  contain  at  the 
base  of  each  a  tiny  honey-gland  or  nectary, 
which  is  covered  by  a  scale  or  small  inner  petal, 
so  to  speak,  to  protect  it  from  the  attacks  of 
thievish  insects.  But  when  the  bee  or  other 
proper  fertilising  agent  arrives  at  the  flower, 
he  lights  on  the  set  of  carpels  in  the  very  centre 
of  the  blossom,  and  proceeds  to  go  straight  for 


VAEIOUS   MAKEIAGE    CUSTOMS.  99 

the  little  store  of  honey.  As  he  does  so,  he 
turns  gradually  round  all  over  the  carpels,  and 
dusts  himself  with  pollen  from  the  ripe  stamens. 

And  now  we  must  notice  another  curious 
device  for  ensuring  cross-fertilisation  in  many 
flowers.  In  the  bulbous  buttercup  the  stamens 
and  carpels  do  not  come  to  maturity  together ; 
the  stamens  ripen  first,  and  after  them  the 
carpels.  How  does  this  ensure  cross-fertilisa- 
tion ?  Why,  if  the  bee  comes  to  a  flower  in  the 
first  or  male  stage,  in  which  the  stamens  are  at 
their  full,  and  discharging  pollen,  the  sensitive 
surfaces  or  stigmas  of  the  carpels  will  yet  be 
immature,  so  that  he  cannot  fertilise  them  with 
pollen  from  their  own  blossom.  He  can  only 
collect  there,  without  disbursing  anything.  But 
as  soon  as  he  comes  to  a  flower  in  its  second  or 
female  stage,  with  the  carpels  ripe,  and  their 
sensitive  surfaces  sticky,  he  will  rub  off  some 
of  the  pollen  he  has  thus  collected,  and  so  cross- 
fertilise  the  flower  he  is  visiting. 

Each  buttercup  thus  goes  through  two  stages. 
First,  its  stamens   ripen  from  without  inward,) 
till   all  have   shed   their  pollen   and  withered.  » 
Then  the  carpels  ripen  in  the  same  order,  till  ^ 
all  have  been  fertilised  by  the  appropriate  insect. 
Each  carpel  here  contains  a  single  seed,  which 
begins  to  swell  as  soon  as  the  ovary  is  impreg- 
nated. 

We  may  take  it  that  some  such  flower  as  that 
of  the  bulbous  buttercup  represents  the  qrig^njjl 
ancestor  of  all  the  buttercup  group,  from  which 
other  kinds  have  varied  in  many  directions. 
Omitting  for  the  present  all  questions  as  to  the 


100        THE  STORY  OF  THE  PLANTS. 

fruit  and  seed,  which  we  must  examine  at  length 
in  a  later  chapter,  I  will  now  proceed  briefly  to 
describe  a  few  of  these  variations  in  the  butter- 
cup family. 

The  true  buttercups  themselves  are  dis- 
tinguished from  all  other  members  of  the  group 
by  having  a  tiny  scale  over  the  nectary  or  honey- 
gland  at  the  base  of  the  petal,  or  at  least  by 
having  the  nectary  itself  as  a  visible  pit  or  small 
depression.  Almost  all  of  them  are  yellow, 
though  in  other  respects  they  differ  from  one 
another,  as  in  the  shape  of  the  leaves,  or  in 
the  way  in  which  the  sepals  are  turned  back 
to  form  a  protection  against  insects.  One  of  the 
yellow  buttercups,  too,  commonly  called  the 
lesser  celandine,  has  varied  from  the  rest  of 
the  race  in  a  peculiar  fashion ;  for  it  has  only 
three  sepals,  instead  of  five,  according  to  the 
usual  pattern ;  while,  as  if  to  make  up  for  this 
loss  in  one  part,  it  has  eight  petals  instead  of 
five  in  its  corolla.  I  merely  mention  this  fact 
to  show  how  many  small  changes  occur  in 
different  flowers,  even  within  the  limits  of  the 
same  family.  And  though  most  of  the  true 
buttercups  are  yellow,  a  few  are  wiiite,  such 
as  our  own  water-crowfoot,  and  the  alpine 
buttercup  called  bachelors'  buttons ;  while  still 
fewer  are  red,  like  the  turban  ranunculus  of  our 
spring  gardens. 

But  besides  the  true  buttercups,  we  have  also 
a  vast  group  of  buttercup-like  plants,  descen- 
dants of  the  same  primitive  five-petalled  an- 
cestor, and  regarded  as  members  of  the  butter- 
cup order.  In  these  we  can  trace  some  curious 


VARIOUS  MARRIAGE  CUSTOMS.       101 

gradations.  The  little  winter  aconite  of  our 
gardens  has  this  peculiarity :  the  petal  and 
nectary  have  grown  into  a  sort  of  tubular  honey- 
cup,  much  more  attractive  to  greedy  insects  than 
the  simple  scale-bearing  petal  of  the  buttercups. 
But  as  this  involves  loss  of  expanded  colour- 
surface,  the  winter  aconite  has  made  up  for 
the  deficiency  by  colouring  its  calyx  a  brilliant 
yellow,  so  as  to  resemble  a  coTolla.  Several 
other  buttercup-like  plants  have  even  lost  their 
petals  altogether,  and  make  coloured  sepals  do 
duty  in  their  place.  The  marsh-marigold,  for 
instance,  is  one  of  these  ;  what  look  like  petals 
in  it  are  really  very  brilliant  yellow  sepals. 
Moreover,  as  the  marsh-marigold  is  such  a  large 
and  handsome  flower,  it  easily  attracts  insects 
in  early  spring  ;  and  this  has  enabled  it  to  effect 
an  economy  in  the  matter  of  its  carpels  or  female 
organs.  In  the  buttercups,  we  saw,  these  were 
very  numerous,  and  each  contained  only  one 
seed  ;  in  the  marsh-marigold,  on  the  other  hand, 
they  are  reduced  to  five  or  ten,  but  each  contains 
a  large  number  of  seeds.  This  arrangement 
enables  a  few  acts  of  fertilisation  to  suffice  for 
the  whole  flower.  You  will  therefore  find  as 
a  rule  that  advanced  types  of  flowers  have  very 
few  carpels — s^rnetimes  only  one — and  that 
wrien  they  are  more  numerous  they  are  often 
combined  into  a  single  ovary,  with  one  sensitive 
surface,  so  that  one  fertilisation  is  enough  for 
the  whole  of  them. 

Three  familiar  but  highly-advanced  members 
of  the  buttercup  group  will  serve  to  show  the 
immense  changes  effected  in  this  respect  by 


102       THE  STORY  OP  THE  PLANTS. 

special  insect  fertilisation.     They  are  the  colum- 
bine, the  larkspur,  and  the  monkshood.     In  the 
simple  buttercups,  the  honey,  we  saw,  was  easily 
accessible  to  many   small  insects ;   but   in  the 
winter   aconite   it   was   made  more    secure   by 
being  kept,  as  it  were,  in  a  sort  of  deep  jar;  and 
in  these  highest  of  the  family  it  is  still  further 
hidden  away,  in  special  nooks  and  recesses,  like 
vases  or  pitchers,  so  as  to  be  only  procurable  by 
bees  and  butterflies.     These  higher  insects,  on 
'  the  other  hand,  are  the  safest  fertilisers,  because 
.  they  have  legs  and  a  proboscis  exactly  adapted 
» to  the  work  they  are  meant  for  ;  and  they  have 
4 also  as  a  rule  a  taste  for  red,  blue,  and  purple 
,  flowers,  rather  than  for  simple  white  or  yellow 
\  ones.     Hence  the  blossoms  that   specially   lay 
1  themselves  out  for  the  higher  insects  are  almost 
\  always  blue  or  purple. 

Columbine  still  retains  the  original  five  sepals 
and  five  petals  of  its  buttercup  ancestor.  But 
the  sepals  here  are  blue  or  purple,  and  are 
displayed  between  the  petals  in  a  most  curious 
manner,  so  as  to  help  in  the  coloured  advertise- 
ment of  the  honey.  The  petals,  on  the  other 
hand,  are  turned  into  long  spurred  horns,  each 
with  a  big  drop  of  honey  in  its  furthest  recess, 
securely  placed  where  only  an  insect  with  a  very 
long  proboscis  has  any  chance  of  reaching  it. 
Within  these  two  rows  come  the  numerous 
stamens  ;  and  within  them  again  a  set  of  five 
carpels,  each  many-seeded.  The  columbine  is 
so  secure  of  getting  its  seed  set  by  bees  or 
butterflies  that  it  is  able  to  dispense  with  the 
extra  carpels. 


VARIOUS  MARRIAGE  CUSTOMS.       103 

Larkspur  carries  the  same  devices   one  step 
further.     Here,   there  are  five  sepals,  coloured 
blue,  and  prolonged  into  a  spur   at   the   base, 
which   covers    the    nectaries.     Why  this   outer 
covering  ?     Well,  in  columbine,  thievish  insects 
like  wasps  often   eat   through  the  base  of  the 
spurred   sepals   and    steal    the  honey,   without 
benefiting  the  plant  in  any  way,  as  they  don't 
come  near  the  stamens  and  carpels.     Larkspur 
provides  against  that  evil  chance  by  covering  its 
honey  with  two  protective  coats  ;  for  within  the 
spur  of  the  sepals  lies  a  spurred  nectary  made 
up   of  the  petals.     The  petals   themselves   are 
reduced  to  two,  because  the  sepals  are  coloured, 
and  do  all  the  attractive  duty ;  and  besides,  even 
these   two  petals  are   combined   into  one,  as  a 
further  economy.     But  the  arrangement  of  the 
flower  is  so  admirable  for  ensuring  fertilisation 
that  the  plant  is  able  still   further  to  dispense 
with  unnecessary  parts  ;  so  many  larkspurs  have 
,  only  a   single   many-seeded    carpel.     Such    re- 
tductions   in    the   numbers  of  parts  are  always 
^a  sign  of  high  development.     Where  the  devices 
for  effecting  the  work  are  poor,  many  servants 
/are   necessary ;    where    labour-saving   improve- 
ments   have    been    largely    introduced,  a  very 
(few  will  do  the  same  work,  and  do  it  better. 

Monkshood,  again,  is  another  example  of  the 
same  tendency.  Here,  the  one-sidedness  which 
we  saw  in  the  larkspur  reaches  a  still  more 
advanced  development.  The  upper  sepal  is 
formed  into  a  brilliant  blue  hood,  and  it  covers 
two  curiously  shaped  petals,  which  contain  an 
abundant  store  of  honey.  This  arrangement  is 


104       THE  STORY  OF  THE  PLANTS. 

so  splendid  for  fertilisation  that  the  plant  is  able 
largely  to  reduce  its  number  of  stamens  ;  and 
though  it  has  three  carpels,  these  are  combined 
at  the  base,  thus  showing  the  first  step  towards 
a  united  ovary. 

I  have  treated  the  single  family  of  the  butter- 
cups at  some  length,  because  I  wished  to  show 
you  what  sort  of  variations  on  a  single  plan 
were  common  in  nature.  We  see  here  a  family, 
built  all  on  one  scheme,  but  altering  its  archi- 
tecture and  decoration  in  the  most  singular 
degree  in  its  different  members.  The  simplest 
4  kinds  are  circular,  symmetrical,  orderly,  and 
yellow ;  the  highest  are  irregular,  somewhat 
strangely  shaped,  and  blue  or  purple.  This  is 
the  general  line  of  evolution  in  flowers.  They 
.  begin  like  the  buttercup ;  they  end  like  the 
monkshood. 

Familiar  instances  of  round  or  radial  flowers, 
consisting  of  separate  petals,  are  the  dog-rose, 
the  poppy,  the  mallow,  and  the  herb-robert  or 
wild  geranium.  Most  of  these  have  five  sepals 
and  five  petals ;  but  in  the  poppy  the  petals  are 
usually  reduced  to  four,  and  the  sepals  to  two. 
Again,  a  good  instance  of  flowers  with  separate 
petals  which  have  become  one-sided  or  irregular, 
instead  of  circularly  symmetrical,  is  afforded  us 
by  the  peaflowers,  which  include  the  pea,  the 
bean,  the  sweet-pea,  the  laburnum,  the  broom, 
the  gorse,  the  vetch,  and  the  lupine.  This 
familiar  family,  known  to  botanists  as  the  papi- 
lionaceous or  butterfly-like  order  (I  trouble  you 
with  as  few  long  names  as  I  can,  so  you  must 


VARIOUS  MARRIAGE  CUSTOMS.      105 

forgive  one  or  two  occasionally),  is  one  of  the 
largest  in  the  world,  and  includes  a  vast  number 
of  the  most  useful  and  also  of  the  most  orna- 
mental species.  Tho  structure  of  the  flower, 
which  is  very  similar  in  them  all,  can  be  easily 
studied  in  the  broom  or  the  sweet-pea,  plants 
procurable  by  everybody.  There  are  still  five 
petals,  though  two  of  them  are  united  to  form 
a  lower  portion  of  the  flower,  known  as  the 
keel;  then  two  others  at  the  side  are  called 
the  wings  ;  while  a  broad  and  often  handsomely 
coloured  advertisement-petal  at  the  top  of  all  is 
called  the  standard.  The  sepals  are  often  com- 
bined into  a  single  calyx-piece,  though  as  a  rule 
the  calyx  still  retains  five  lobes  or  teeth,  a 
reminiscence  of  the  time  when  it  consisted  of 
five  distinct  and  separate  sepals.  The  stamens 
are  welded  together  into  a  sort  of  long  tube  ;  and 
the  pistil  is  reduced  to  a  single  carpel  or  pod, 
containing  a  few  big  seeds,  very  familiar  to  most 
of  us  in  the  case  of  the  pea,  the  bean,  and  the 
scarlet-runner.  This  shape  of  flower  has  proved 
so  successful  in  the  struggle  for  life  that  papi- 
lionaceous plants  are  now  common  everywhere, 
while  hundreds  of  different  kinds  are  known  in 
various  countries. 

Yet  closely   as  the   peaflowers   resemble  one 
another  in  general  aspect,  they  have  still  among 
themselves  a  curious  variety  of  marriage  customs. 
I  will   mention   two   only.     In   gorse,  a  flower  r 
which  everybody  can  easily  examine,  the  wings  I 
have  two  little  knobs  at  the  sides  for  the  bee  to  | 
alight  upon.     As  he  does  so,  the  corolla  springs  j 
open  elastically,  and  dusts  him  all  over  with  the  i 


106       THE  STOKY  OF  THE  PLANTS. 

fertilising  pollen.  But  once  it  has  burst,  it  re- 
mains permanently  open,  the  keel  hanging  down 
in  a  woe-begone  way,  so  that  no  bee  troubles 
himself  again  to  visit  it.  This  saves  time  for  the 
bees,  and  enables  them  quicker  to  fertilise  the 
remaining  flowers ;  for  when  they  see  a  gorse- 
blossom  "  sprung  "  as  we  call  it,  they  recognise 
at  once  that  it  has  already  been  fertilised,  and 
they  know  they  can  get  no  food  by  going  there. 
In  the  lupine,  on  the  other  hand,  and  in  the 
common  little  English  birdsfoot-trefoil,  the  keel 
is  sharp  at  the  point,  and  the  pollen  is  shed  into 
it  before  the  flower  fully  opens.  When  a  bee 
lights  on  the  knobs  at  the  side,  he  depresses  the 
1  keel,  and  the  pollen  is  pumped  out  against  his 
breast  in  the  most  beautiful  manner.  I  hope 
my  readers  will  try  some  of  these  experiments  in 
summer  for  themselves,  and  satisfy  their  own 
minds  whether  these  things  are  so. 

So  far,  we  have  dealt  mainly  with  flowers  in 
which  the  petals  are  all  still  distinct  and 
separate.  But  in  a  great  many  plants,  the  petals 
have  grown  together,  so  as  to  form  a  single 
piece,  a  "tubular  corolla,"  as  we  call  it.  This 
arrangement  is  very  well  seen  in  the  harebell, 
the  Canterbury  bell,  the  heath,  and  the  con- 
volvulus. How  did  such  an  arrangement  arise  ? 
Well,  in  many  flowers  even  with  distinct  petals 
there  is  a  slight  tendency  for  adjacent  parts  to 
adhere  at  the  base  ;  and  in  certain  blossoms 
this  tendency  to  adhesion  must  have  benefited 
the  plant,  because  it  would  allow  the  proper 
fertilising  insect  to  get  in  with  ease,  and  to  find 


VABIOUS  MARRIAGE  CUSTOMS. 


107 


his  way  at  once  to  the  stamens  and  stigma  or 
sensitive  surface.  The  consequence  is  that  the 
majority  of  the  higher  plants  have  now  corollas 
in  a  single  piece ;  and  most  of  these  are  also 
coloured  red,  blue,  or  purple.  Still,  even  now 
many  of  them  retain  marks  of  the  original  five 


FIG.  18. — PIN-EYED  PRIMROSE, 
CUT  OPEN  SO  AS  TO  SHOW 
THE  ARRANGEMENT  OF  THE 
STAMENS  AND  STIGMA. 


FIG.  19. — THRUM-EYED 
PRIMROSE,  CUT  OPEN 
SO  AS  TO  SHOW  STA- 
MENS AND  STIGMA. 


petals.  For  instance,  the  harebell  has  the  edge 
of  the  corolla  vandyked  into  five  marked  lobes  ; 
while  in  the  primrose,  only  the  base  of  the 
corolla  forms  a  tube  or  united  pipe,  the  outer 
part  being  composed  of  five  deeply-cut  lobes, 


108       THE  STORY  OP  THE  PLANTS. 

reminiscences  of  the  five  original  petals.  Indeed, 
some  relations  of  the  primrose,  such  as  the  pim- 
pernel and  the  woodland  loose-strife,  have  the 
petals  only  slightly  united  at  the  base,  and 
would  hardly  be  noticed  by  a  casual  observer 
as  possessing  a  tubular  corolla. 

There  is  one  marriage  custom  of  the  primrose, 
however,  so  very  interesting  that  we  must  not  pass 
it  by  even  in  so  brief  a  survey.  Most  children 
are  aware  that  we  have  in  our  woods  two  kinds 
of  primroses,  which  they  know  respectively  as 
pin-eyed  and  thrum-eyed.  In  the  pin-eyed 
form  (Fig.  18),  only  the  little  round  stigma  is 
visible  at  the  top  of  the  pipe,  while  the  stamens, 
here  joined  with  the  corolla-tube,  hang  out  like 
little  bags  half-way  down  the  neck  of  it.  In  the 
thrum-eyed  form  (Fig.  19),  on  the  other  hand, 
only  the  stamens  are  visible  at  the  top  of  the 
tube,  while  the  stigma,  erected  on  a  much 
shorter  style,  occupies  just  the  same  place  in 
the  tube  that  the  stamens  occupied  in  the  sister 
blossom.  Now,  each  primrose  plant  bears  only 
one  form  of  flower.  Therefore,  if  a  bee  begins 
visiting  a  thrum-eyed  form,  he  will  collect  pollen 
on  his  proboscis  at  the  very  base  only ;  and  as 
long  as  he  goes  on  visiting  thrum-eyed  flowers, 
he  can  only  collect,  without  getting  rid  of  any 
grains  on  the  deep-set  stigmas.  But  when  he 
flies  away  to  a  pin-eyed  blossom,  the  part  of  his 
proboscis  which  collected  pollen  before  will  now 
be  opposite  the  stigma,  and  will  fertilise  it ; 
while  at  the  same  time  he  will  be  gathering 
fresh  pollen  below,  to  be  rubbed  off  on  the  sensi- 
tive surface  of  a  short- sty  led  flower  in  due  season. 


VA1UOUS    MAEKIAGE    CUSTOMS.  109 

Thus  every  pin-eyed  blossom  must  always  be 
fertilised  by  a  thrum-eyed,  and  every  thrum-eyed 
by  a  pin-eyed  neighbour.  This  is  one  of  the 
most  ingenious  arrangements  known  for  cross- 
fertilisation. 

Much  as  I  should  like  to  dwell  further  on 
these  interesting  cases,  I  must  hurry  on  to 
complete  our  rapid  survey  of  a  great  subject. 
Flowers  like  the  harebell  and  the  primrose  are 
tubular  but  regular.  Other  flowers  with  a 
tubular  corolla  go  yet  a  step  further  and  are 
irregular  also.  This  irregularity,  like  that  of 
the  monkshood,  secures  for  them  in  the  end 
greater  certainty  of  fertilisation.  Two  well- 
known  groups  of  this  sort  are  the  sages,  on  the 
one  hand,  and  the  fox-gloves,  monkey-plants, 
and  snap-dragons  on  the  other.  I  shall  mention 
only  one  instance  of  special  devices  for  cross- 
fertilisation  in  these  groups,  that  of  the  various 
sages,  beautifully  seen  in  the  large  blue  salvias 
of  our  gardens.  In  this  plant  there  are  only  two 
stamens,  though  most  of  the  group  to  which  it 
belongs  have  four,  because  the  excellent  ar- 
rangements for  fertilisation  make  this  single 
pair  a  great  deal  more  effective  than  the  thirty 
or  forty  required  by  the  common  buttercup. 
For  the  stamens  are  delicately  poised  on  a  sort 
of  lever,  so  that  the  moment  the  bee  enters  the 
flower,  they  descend  and  embrace  him,  as  if  by 
magic.  While  the  stamens  alone  are  ripe,  this 
continues  to  happen  with  each  flower  he  visits  ; 
but  when  he  goes  away  to  an  older  blossom,  he 
finds  the  stigma  ripe,  and  bending  over  into  the 


110        THE  STORY  OF  THE  PLANTS. 

spot  previously  occupied  by  the  stamens.  You 
can  try  this  experiment  very  easily  for  yourself 
by  putting  a  straw  or  bent  of  grass  down  the 
tube  of  a  garden  salvia,  when  the  stamens  will 
at  once  bend  down  and  embrace  it  in  the  way  I 
have  mentioned. 

You  must  not  suppose,  however,  that  all 
flowers  are  fertilised  by  bees  and  butterflies. 
Many  plants  lay  themselves  out  for  quite  dif- 
ferent visitors.  Take  for  example  our  common 
English  figwort.  This  is  a  curious,  lurid-looking, 
reddish-brown  blossom,  shaped  somewhat  like  a 
helmet,  and  it  is  fertilised  almostexplusively  by 
wasps.  Its  shape  and  size  exactlyaSapt  it  for 
aTwasp's  head  ;  and  it  blooms  at  the  time  of 
year  when  wasps  are  numerous.  Now  wasps, 
as  you  know,  are  carnivorous  and  omnivorous 
creatures  ;  so  the  figwort,  to  attract  them,  looks 
as  meaty  as  it  can,  and  has  an  odour  not  unlike 
that  of  decaying  mutton.  Certain  tropical  flowers 
again  attract  carrion-flies,  and  these  have  big 
blossoms  that  look  like  decomposing  meat,  and 
smell  disgustingly.  A  South  African  flower  of 
this  sort,  the  Stapelia,  is  sometimes  cultivated 
as  a  curiosity  in  greenhouses.  I  have  already 
remarked  on  the  white  flowers  which  open  at 
night,  and  attract  tEe^moths  of  twilight ;  while 
others  again  lay  themselves  out  to  be  fertilised 
by  midges,  beetles,  and  other  insect  riff-raff. 
Most  of  these  have  the  honey  displayed  on  wide 
open  discs,  where  it  can  be  sipped  by  insects 
with  hardly  any  proboscis. 

In  our  latitudes  it  is  only  insects  that  so  act 


VAEIOUS    MARRIAGE    CUSTOMS.  Ill 

as  fertilisers  ;  but  in  the  tropics  the  work  of 
fertilisation  is  often  performed  by  birds,  such  as 
humming-birds,  sun-birds,  and  brush-tongued 
lories.  Many  of  the  most  brilliant  and  beautiful 
among  the  bell-shaped  tropical  flowers  have  been 
specially  developed  to  suit  the  tastes  and  habits 
of  these  comparatively  large  and  powerful  ferti- 
lisers. The  tongues  of  all,  but  especially  of  the 
humming-birds,  are  admirably  adapted  for  suck- 
ing honey  from  flowers,  as  they  are  long  and 
tubular,  sometimes  forked  at  the  tip,  and  often 
hairy  so  as  to  lick  up  both  honey  and  insects. 
The  length  of  the  beak  "and  tongue  varies  to  a 
great  extent  in  accordance  with  the  depth  of  the 
tube  in  the  flowers  they  fertilise.  Bird  and 
flower,  in  other  words,  have  each  been  developed 
to  suit  one  another.  The  same  sort  of  corre- 
spondence may  often  be  observed  between  in- 
sects and  flowers  developed  side  by  side  for 
mutual  convenience. 

One  more  point  I  should  like  to  touch  upon 
before  I  pass  away  from  this  part  of  the  subject ; 
and  that  is  the  lines  or  spots  so  often  found  on 
the  petals  of  highly  developed  flowers.  These 
for  the  most  part  act  as  honey-guides,  to  lead 
the  bee  or  other  fertilising  insect  direct  to  the 
nectar.  A  very  good  case  of  this  may  be  seen 
in  an  Indian  plant  which  is  found  in  every 
English  cottage  garden — that  is  to  say  the  so- 
called  nasturtium.  This  beautiful  blossom  can  » 
only  be  fertilised  by  humming-bird  hawk-moths, 
no  other  insect  in  Europe  at  least  having  a  L 
proboscis  long  enough  to  reach  to  the  bottom  of  J 


112        THE  STOEY  OF  THE  PLANTS. 

the  very  deep  spur  which  holds  the  honey. 
Now,  humming-bird  hawk-moths  do  not  light 
on  a  flower,  but  hover  lightly  poised  on  their 
quivering  wings  in  front  of  it.  So  all  the  ar- 
rangements of  the  flower  are  strictly  set  forth  in 
accordance  with  the  insect's  habit.  The  calyx 
consists  of  five  sepals  with  a  very  long  spur,  the 
end  of  which,  as  you  can  find  out  by  biting  it,  is 
full  of  honey.  Then  come  five  petals,  not,  how- 
ever, all  alike,  but  divided  into  two  distinct  sets, 
an  upper  pair  and  a  lower  triplet.  The  upper 
pair  are  broad  and  deeply-lined  with  dark  veins, 
which  all  converge  about  the  mouth  of  the  spur, 
and  so  show  the  inquiring  insect  exactly  where 
to  go  in  search  of  honey.  The  lower  three,  on 
the  other  hand,  have  no  lines  or  marks,  but 
possess  a  curious  sort  of  fence  running  right 
across  their  face,  intended  to  prevent  other 
flying  insects  from  alighting  and  rifling  the 
flower  without  fertilising  the  ovary.  This 
flower,  too,  has  two  successive  stages ;  it  opens 
male,  with  stamens  only,  which  bend  upward 
towards  the  insect ;  later,  it  becomes  female, 
the  stigma  opens  and  becomes  forked,  and  bends 
down  so  as  to  occupy  the  very  same  place  pre- 
viously occupied  by  the  ripe  stamens. 

A  great  many  well-known  flowers  have  such 
lines  as  honey-guides.  If  I  have  succeeded  so 
far  in  interesting  you  in  the  subject,  you  will 
find  it  a  pleasant  task  to  hunt  them  out  for 
yourself  in  the  violet,  the  scarlet  geranium,  the 
spotted  orchid,  and  the  tiger  lily. 

So  far  I  have  dealt  only  with  the  marriage 


MOKE  MAURI  AGE  CUSTOMS.        113 

arrangements  of  those  plants  which  are  fertilised 
by  insects  or  birds,  and  which  belong  to  the 
great  group  of  flowering  plants  descended  from 
an  early  common  ancestor  with  five  petals.  We  j 
must  next  deal  briefly  with  the  marriage  customs 
of  the  insect-fertilised  class  among  the  other 
great  group  whose  ancestor  started  with  but 
three  petals ;  and  after  that  we  must  go  on  to 
the  other  mode  of  fertilisation  by  means  of  the 
wind  or  of  self -impregnation. 

This  chapter  has  consisted  so  much  of  special 
cases  that  I  do  not  think  it  stands  in  the  same 
need  of  a  summary  as  all  its  predecessors. 


CHAPTEK  VIII. 

MORE  MARRIAGE  CUSTOMS, 

ALMOST  all  the  flowering  plants  with  which  most 
people  are  familiar — all,  indeed,  save  the  pines 
and  other  conifers — belong  to  one  or  other  of 
two  great  groups  or  alliances,  each  remotely 
descended  from  a  common  ancestor.  The 
flowers  we  have  hitherto  been  considering  are 
entirely  those  which  belong  to  one  out  of  these 
two  groups — the  group  which  started  with  rows 
of  five,  having  five  sepals,  five  petals,  five  or  ten 
stamens,  and  five  or  ten  carpels.  In  several 
cases,  certain  of  these  rows  have  been  simplified 
or  reduced  in  number ;  but  almost  always  we 
can  see  to  the  end  some  trace  of  the  original 
fivefold  arrangement.  This  fivefold  arrangement 
is  very  conspicuous  in  all  the  stonecrops,  and  it 
8 


114       THE  STORY  OF  THE  PLANTS. 

may  also  be  well  noticed  in  wild  geraniums,  and 
less  well  in  the  strawberry,  the  dog-rose,  and  the 
cinquefoil. 

In  the  present  chapter,  however,  I  propose  to 
go  on  to  sundry  flowers  of  the  other  great  group 
which  has  its  parts  in  rows  of  three,  and  to 
show  how  they  have  been  affected  By  insect 
visits.  This  will  give  us  a  clearer  view  of  the 
whole  subject,  while  it  will  also  form  a  general 
introduction  to  systematic  botany  for  those  of 
my  readers  who  may  be  induced  by  this  book  to 
carry  their  studies  in  this  direction  further. 

Before  proceeding,  however,  there  is  one  little 
point  I  should  like  to  note  about  the  fivefold 
flowers,  which  we  shall  find  much  more  common 
in  the  threefold,  and  among  the  wind-fertilised 
species.  This  is  the  separation  of  the  sexes  in 
different  blossoms  or  even  on  separate  plants. 
All  the  flowers  we  have  so  far  considered  have 
contained  both  male  and  female  portions — have 
been  made  up  of  stamens  and  carpels  united 
together  in  the  self -same  blossom.  But  many 
of  them,  as  you  will  recollect,  have  not  been 
actively  both  male  and  female  at  the  same 
moment.  The  stamens  ripened  first,  the  sensi- 
tive surface  of  the  carpels  afterwards ;  and  this, 
as  we  saw,  tended  to  promote  cross-fertilisation. 
But  if  in  any  species  all  the  stamens  in  certain 
flowers  were  to  be  suppressed  or  undeveloped, 
while  in  other  flowers  the  same  thing  happened 
to  the  carpels,  self-fertilisation  would  become  an 
absolute  impossibility,  and  every  blossom  would 
|  necessarily  be  impregnated  from  the  pollen  of  a 
\  neighbour.  Natural  selection  has  accordingly 


MORE  MARRIAGE  CUSTOMS.        115 

favoured  such  an  arrangement  in  a  considerable  j 
number  of  the  higher  plants.  In  such  cases 
some  of  the  flowers  consist  of  stamens  only, 
with  no  carpels ;  while  others  consist  of  carpels 
alone,  with  no  stamens.  But  as  all  are  de- 
scended from  ancestors  which  had  both  organs 
combined  in  the  same  flower,  remnants  of  the 
stamens  often  exist  in  the  female  flowers  as 
naked  filaments  or  barren  threads,  while 
remnants  of  the  carpels  equally  exist  in  the 
male  flowers  as  central  knobs  without  seeds  or 
ovules. 

The  beautiful  begonias,  so  much  cultivated  in 
conservatories,  give  us  an  excellent  example  of 
such  single-sex  flowers.  In  these  plants  the 
males  and  females  are  extremely  different.  The 
male  flower  has  four  coloured  and  petal-like 
sepals,  surrounding  a  number  of  central  stamens. 
The  female  flower  has  five  coloured  and  petal-like 
sepals,  surrounding  a  group  of  daintily-twisted 
central  stigmas,  while  at  the  base  of  the  blossom 
is  a  large  triangular  ovary,  containing  the  young 
seeds  or  ovules.  Usually  the  flowers  grow  in 
little  bunches  of  three,  each  bunch  consisting  of 
two  males  and  one  female. 

In  the  pumpkins,  cucumbers,  and  melons, 
separate  male  and  female  flowers  also  exist  on 
the  same  plant.  The  females  here  may  be  easily 
recognised  by  having  an  ovary  or  small  unde- 
veloped fruit  at  the  back  of  the  blossom,  which 
you  can  cut  across  so  as  to  show  the  young 
seeds  or  ovules  within  it.  As  the  proper  insects 
for  fertilising  cucumbers  and  melons  do  not  live 
in  England,  gardeners  usually  impregnate  the 


116       THE  STORY  OF  THE  PLANTS. 

female  flowers  by  bringing  pollen  from  the  males 
1    to  them  with  a  camel's  hair  brush.     This  pro- 
cess  is   commonly    known    as   "  setting "    the 
f  melons.      Many    other    garden    flowers    have 
I  separate  male  and  female  blossoms,  which  the 
\  beginner  can  easily  recognise  for  himself  if  he 
takes  the  trouble  to  look  for  them. 

In  the  instances  we  have  hitherto  considered, 
the  male  and  female  blossoms  live  on  the  same 
plant.  But  the  best  cross-fertilisation  of  all  is 
that  which  is  secured  where  the  fathers  and 
I  mothers  belong  to  totally  distinct  plants,  a  plan 
J  for  facilitating  which  we  have  already  seen  in 
^the  common  primrose.  Well,  now,  if  any 
species  took  to  producing  all  male  flowers  on 
one  plant,  and  all  females  on  another,  this  great 
end  would  become  absolutely  certain,  for  every 
blossom  would  then  always  be  fertilised  by  the 
pollen  brought  from  a  distinct  plant.  Many  such 
instances  have  accordingly  been  produced  in  the 
world  around  us  by  natural  selection.  Only,  the 
two  kinds  of  plants  must  always  grow  in  one 
another's  neighbourhood.  Hemp,  for  example, 
is  a  case  of  a  plant  where  such  an  arrangement 
already  exists  ;  some  plants  are  male  only,  while 
some  are  female.  Mistletoe  and  hops  are  other 
well-known  instances,  which  the  reader  should 
carefully  examine  for  himself  at  the  proper 
season. 

All  these  are  fivefold  flowers,  and  I  have 
brought  them  in  here  merely  because  one  of 
the  earliest  and  simplest  threefold  flowers  we 
are  going  to  consider  has  also  this  peculiarity 


MORE   MARRIAGE   CUSTOMS.  117 

of  separate  sexes.  This  is  the  common  arrow- 
head, a  plant  that  grows  in  watery  ditches,  and 
a  capital  example  of  the  threefold  type  in  its 
simpler  development.  Each  flower,  whether 
male  or  female,  has  a  green  calyx  of  three  small 
sepals,  and  a  white  corolla  of  three  much  larger 
and  somewhat  papery  petals  (Fig.  20).  ^  But  the 
male  flowers  have  in  their  centre  an  indefinite 
number  of  clustering  stamens ;  while  the  female 
flowers  have  an  equally  numerous  set  of  tiny 
carpels.  The  blossoms  grow  in  whorls  on  the 


II 


FIG.   20. — I.   MALE,    AND   II,    FEMALE   FLOWEKS 
OF   ARROWHEAD. 

same  stem,  the  males  above,  the  females  beneath 
them*  At  first  sight  you  would  think  this  a  bad 
arrangement,  because  you  might  fancy  pollen 
from  the  males  would  certainly  fall  or  blow  out 
upon  the  females  beneath  them.  But  the  plant 
prevents  that  catastrophe  by  a  very  simple 
dodge,  which  we  shall  have  occasion  to  notice 
in  many  other  parallel  cases.  The  flowers  open 
from  below  upward ;  thus  the  females  mature 
first,  and  are  fertilised  by  insects  which  bring  to 
fliSm.  pollen  from  other  plants  already  rifled ; 
later  on  the  males  follow  suit,  and  their  pollen 


118       THE  STORY  OF  THE  PLANTS. 

is  carried  off  by  the  visiting  insect  to  the  female 
flowers  on  the  next  plant  it  visits.  Indeed,  you 
may  gather  by  this  time  how  great  a  variety 
of  devices  natural  selection  has  produced  for 
securing  this  great  desideratum  of  fresh  blood, 
or  cross-fertilisation,  from  a  totally  distinct  plant 
colony. 

A  much  commoner  English  wild-flower  than 
the  arrowhead  shows  us  another  form  of  early 
threefold  blossom.  I 
mean  the  water-plan- 
tain (Fig.  21),  a  pretty 
feathery  weed,  which 
grows  by  the  side  of 
most  ponds  and  lake- 
lets. In  the  water- 
plantain  you  have  a 
flower  of  both  sexes 
combined ;  it  consists 
of  three  green  sepals, 

FIG.    21.— FLOWER     OF     WATER-  fnrrrijnfy       o        rirofppHvP 

PLANTAIN.     The  male  and  to™mg     a     P10™ 
female  parts  are  in  the  same  calyx  '>     tnree     delicate 
blossom.  pinky  -  white      petals, 

forming    the     corolla ; 

six  stamens — that  is  to  say,  two  rows  of  three 
each ;  and  a  number  of  small  one- seeded  carpels, 
exactly  as  in  the  buttercup,  which  occupies,  in 
fact,  the  corresponding  place  among  the  fivefold 
flowers. 

But  it  is  not  often  in  the  threefold  flowers  that 
we  get  the  calyx  green  and  the  corolla  coloured, 
as  in  these  simple  and  very  early  types.  Most 
often  in  this  great  group  of  plants  the  calyx  and 
corolla  are  both  brightly  coloured,  and  both  alike 


MOKE   MAEBIAGE    CUSTOMS.  119 

employed  as  effective  advertisements.  A  good 
case  of  this  sort  is  shown  in  the  flowering-rush, 
a  close  relation  of  the  arrowhead  and  the  water- 
plantain,  but  a  more  advanced  and  deve- 
loped plant  than  either  of  them.  Here  the 
calyx  and  corolla,  instead  of  forming  two  sepa- 
rate rows,  are  telescoped  into  one,  as  it  were, 
and  are  both  rose-coloured.  In  such  cases  we 
speak  of  the  combined  calyx  and  corolla  as  the 
perianth  (another  long  word,  with  which  I'm 
sorry  to  trouble  you).  In  such  perianths,  how- 
ever, even  when  all  the  pieces  are  of  the  same 
size  and  are  similarly  coloured,  you  can  see  if 
you  look  close  that  three  of  them  are  outside 
and  alternate  with  the  others ;  and  these  three 
are  really  the  calyx  in  disguise,  got  up  as  a 
corolla.  (An  excellent  example  of  this  arrange- 
ment is  afforded  by  the  common  garden  tulip.) 
Inside  its  six  rose-coloured  perianth-pieces,  the 
flowering-rush  has  nine  stamens,  arranged  in 
three  rows  of  three  stamens  each.  Finally,  in 
the  centre,  it  has  six  carpels,  equally  arranged 
in  two  rows  of  three.  Here  the  threefold 
architectural  ground-plan  of  the  flower  is  very 
apparent.  You  may  say,  in  short,  that  the 
original  scheme  of  the  two  great  groups  is  some- 
thing like  this :  five  sepals,  five  petals,  five 
stamens,  five  carpels ;  or  else,  three  sepals, 
three  petals,  three  stamens,  three  carpels.  But 
in  any  instance  there  may  be  two  or  more  such 
rows  of  any  organ,  especially  of  the  stamens ; 
in  any  instance  certain  parts  may  be  reduced 
in  number  or  entirely  suppressed ;  and  in  any 
instance  calyx  and  corolla  may  be  coloured 


120       THE  STORY  OF  THE  PLANTS. 

alike  so  as  almost  to  resemble  a  single  row  or 
perianth. 

There  is  one  more  point  about  the  flowering- 
rush  to  which  I  would  like  to  allude  before  going 
on  to  the  other  threefold  flowers,  and  that  is 
this.  In  arrowhead  and  water-plantain  the 
carpels  are  very  numerous,  but  each  one-seeded. 
In  flowering-rush,  on  the  other  hand,  which  has 
a  larger  and  handsomer  blossom,  more  attractive 
to  insects,  they  are  reduced  to  six ;  but  these 
six  have  many  seeds  in  each,  so  that  a  single 
act  of  fertilisation  suffices  for  each  of  them. 
You  may  remember  that  among  the  fivefold 
flowers  we  found  a  precisely  similar  advance  on 
the  part  of  the  marsh-marigold  above  the 
bulbous  and  meadow  buttercups.  This  sort  of 
advance  is  common  in  nature.  Where  a  flower 
learns  how  to  produce  many  seeds  in  a  carpel, 
it  can  soon  dispense  with  several  of  its  carpels, 
because  a  few  now  do  well  what  the  many  did 
badly.  Furthermore,  in  higher  plants,  there  is 
a  tendency  for  these  carpels  to  unite  so  as  to 
form  what  we  call  a  compound  ovary,  with  a 
single  style,  when  one  act  of  fertilisation  suffices 
for  all  of  them.  Such  combinations  or  labour- 
saving  arrangements  obviously  benefit  both  the 
insect  and  the  plant,  and  have  therefore  been 
doubly  favoured  by  natural  selection. 

We  see  this  advance  beautifully  illustrated  in 
the  largest  and  loveliest  family  of  the  threefold 
flowers,  the  lily  group,  which  contains  a  great 
number  of  the  handsomest  insect  -  fertilised 
blossoms,  and  is  therefore  deservedly  an  im- 
mense favourite  in  flower-gardens.  All  the  lilies 


MOKE  MAKKIAGE  CUSTOMS.       121 

have  a  perianth  (or  combined  calyx  and  corolla) 
of  six  almost  similar  HrTfTiantly-coloured  pieces 
(in  which,  however,  you  can  still,  as  a  rule, 
detect  the  sepals  by  their  habit  of  overlapping 
the  petals  in  the  bud).  Then  they  have  a  set  of  ; 
six  stamens.  Inside  that,  again,  they  have  a 
single  ovary,  but  if  you  cut  it  across  with  a 
penknife  you  will  see  at  once  it  contains  three 
chambers,  each  as  a  rule  with  several  seeds  j'lmd 
these  three  chambers  are  a  memorv^of  the  time 
when  the  ovary  consistecT  of  three  t  separai^ 
carpels.  From  their  midst  arises~^TsingfeTiong 
style ;  but  you  may  observe  all  the  same  that  it 
is  made  up  of  ffixea  o^jgjnfll  a.nfl  rh'nt.JTinti  iiliT^Tj' 
because  it  divides  at  the  top  into  three  stigmas 
or  sensitive  surfaces.  This  is  the  general  plan 
of  the  lily  group ;  but  in  certain  individual 
lilies  the  stigma  is  undivided,  and  in  others 
again  the  parts  are  increased  to  four  or  even  to 
eight,  so  as  to  obscure  the  primitive  threefold 
arrangement. 

Most  of  the  large  and  handsome  lilies  culti- 
vated in  gardens  have  perianths  of  separate 
pieces,  such  as  one  knows  so  well  in  the  tiger- 
lily,  the  Turk's-cap  lily,  and  the  beautiful  Japa- 
nese lilium  auratum.  They  have  also  abundant 
honey,  stored  in  a  deep  groove  of  the  spotted 
petals,  and  they  are  variegated  and  lined  in  such 
a  way  as  to  guide  insects  direct  to  their  store  of 
nectar.  But  the  family  has  been  so  successful 
with  the  higher  insects,  and  has  produced  such 
an  extraordinary  variety  of  very  beautiful  and 
brilliant  flowers,  that  it  is  quite  impossible  to 
speak  of  them  in  detail.  A  few  among  them, 


122       THE  STOKY  OF  THE  PLANTS. 

like  our  own  wild  hyacinth,  show  a  slight  ten- 
dency on  the  part  of  the  petals  and  sepals  to 
unite  into  a  bell-shaped  tube  ;  still,  even  here 
the  pieces  are  really  distinct  and  separate.  But 
in  the  true  garden  hyacinth  the  pieces  unite  into 
a  tubular  perianth,  like  the  tubular  corolla  of 
the  common  harebell,  except  that  in  the  harebell 
the  tube  is  formed  by  the  union  of  the  five 
petals,  while  in  the  hyacinth  it  is  formed  by  the 
similar  union  of  three  petals  and  three  sepals. 
A  still  higher  form  of  the  same  union  is  shown 
us  by  the  lily-of-the-valley,  in  which  the  six 
perianth-pieces  join  throughout  to  form  a  very 
beautiful  heather  -  like  cup  or  goblet.  Other 
familiar  members  of  this  great  lily  group,  which 
you  ought  to  examine  at  leisure  for  yourself,  in 
order  to  see  how  they  are  built  up,  are  aspa- 
ragus, Solomon's  seal,  fritillary,  tulip,  star-of- 
Bethlehem,  squill,  garlic,  onion,  tuberose,  and 
asphodel.  The  cultivated  lilies  of  one  sort  or 
another  to  be  found  in  our  gardens  may  be 
numbered  by  hundreds. 

A  family  of  threefold  flowers  almost  as  beauti- 
ful as  the  lily  group,  and  seldom  distinguished 
from  them  save  by  botanists,  is  that  which 
bears  the  pretty  Greek  name  of  amaryllids.  The 
amaryllids  are  lilies  which  differ  from  the  rest 
of  their  kind,  in  the  fact  that  the  perianth,  still 
composed  of  six  pieces,  has  grown  up  and  around 
the  ovary  so  as  to  seem  to  spring  from  above  it, 
not  below  it.  Such  flowers  are  said  to  have 
"inferior  ovaries."  In  other  respects  the 
amaryllids  closely  resemble  the  lilies,  having 
six  coloured  perianth-pieces,  six  stamens,  and 


MORE  MARRIAGE  CUSTOMS.        123 

an  ovary  of  three  chambers,  with  one  style  in 
common.  Several  of  the  amaryllids  are  such 
familiar  flowers  that  I  shall  venture  to  describe 
them  as  illustrative  examples. 

The  snowdrop  is  an  amaryllid  which  blossoms 
in  early  spring,  and  which  shows  in  a  simple 
form  the  chief  features  of  the  family.  It  has  six 
perianth-pieces,  but  these  are  still  distinctly 
recognisable  as  calyx  and  corolla.  The  three 
sepals  are  large  and  pure  white,  and  they 
enclose  the  petals ;  the  three  petals  are  dis- 
tinctly smaller,  and  tipped  with  green  in  a  very 
pretty  fashion.  The  summer  snowflake,  com- 
monly cultivated  in  old-fashioned  gardens,  is 
very  like  the  snowdrop,  only  here  the  difference 
between  sepals  and  petals  has  disappeared ;  all 
six  pieces  form  one  apparent  row,  white,  tipped 
with  green,  in  a  single  perianth. 

In  the  daffodils  and  narcissuses  we  get  a 
second  group  of  amaryllids  more  advanced  and 
developed.  Here  the  six  perianth-pieces  are 
almost  alike,  though  they  may  still  be  distin- 
guished as  sepals  and  petals  by  a  careful  ob- 
server. But  the  perianth,  which  is  tubular 
below,  divides  above  into  six  lobes,  beyond 
which  it  is  prolonged  again  into  what  is  called 
a  crown,  whose  real  nature  can  only  be  under- 
stood by  comparison  with  such  other  flowers  as 
the  campions,  where  scales  are  inserted  on  the 
tip  of  the  petals.  This  crown  is  comparatively 
little  developed  in  the  narcissus  and  the  jonquil; 
but  in  the  daffodil  it  has  become  by  far  the 
largest  and  most  conspicuous  part  of  the  entire 
flower,  so  as  completely  to  hide  the  bee  who 


124       THE  STOEY  OF  THE  PLANTS. 

visits  it.  Of  course  this  large  crown  assists 
fertilisation,  and  is  a  mark  of  advance  in  the 
daffodil  and  the  petticoat  narcissus.  I  hope 
these  few  remarks  will  induce  you  to  examine 
many  kinds  of  narcissus  in  detail,  in  order  to 
see  of  what  parts  they  are  compounded. 

This  seems  a  convenient  place  to  interpose 
another  remark  I  have  long  wanted  to  make, 
namely,  that  the  threefold  flowers  are  also  for 
the  most  part  distinguished  by  having  those 
narrow  grass-like  or  sword-shaped  leaves,  with 
parallel  ribs  or  veins,  about  which  I  told  you 
when  we  were  dealing  with  the  question  of 
varieties  of  foliage.  The  fivefold  flowers,  on 
the  other  hand,  have  usually  net-veined  leaves, 
either  feather-ribbed  or  finger-ribbed.  And  at 
the  risk  of  using  two  more  horrid  long  words,  I 
shall  venture  to  add  that  botanists  usually  speak 
of  the  threefold  group  as  monocotyledons,  and  of 
the  fivefold  group  as  dicotyledons.  I  did  not 
invent  those  words,  and  I  am  sorry  to  have 
to  use  them  here ;  but  I  will  explain  what 
they  mean  when  I  come  to  deal  with  seeds  and 
seedlings.  It  is  well  at  least  to  understand 
their  use  in  case  you  come  across  them  in  your 
future  reading. 

Another  family  of  threefold  flowers,  closely 
allied  to  the  amaryllids,  is  that  of  the  irises, 
many  examples  of  which  are  familiar  in  our 
flower-gardens.  It  only  differs  from  the  ama- 
ryllids, in  fact,  in  having  the  number  of  stamens 
still  further  reduced  to  three,  which  is  always 
a  sign  of  advance^  because  it  shows  that  the 
plants  are  so  sure  of  fertilisation  as  to  be  able 


MORE  MARRIAGE  CUSTOMS.        125 

to  dispense  with  all  unnecessary  pollen.  The 
ovary  is  also  inferior,  which  you  will  learn  in 
time  to  recognise  as  a  constant  sign  of  high 
development,  because  it  means  that  the  base  of 
the  corolla  and  calyx  have  coalesced  with  the 
carpels,  and  so  ensured  greater  certainty  of 
fertilisation.  Some  simple  members  of  the 
iris  group,  like  the  crocuses,  have  mere  tubular 
flowers,  with  a  very  long  funnel-like  base  to 
the  corolla,  and  with  the  ovary  buried  in  the 
ground  for  greater  safety.  They  are  early 
spring  blossoms,  which  need  much  protection 
against  cold;  therefore  they  thus  bury  their  ova- 
ries, and  sheathe  their  flower-buds  in  a  papery 
covering,  composed  of  a  thin  and  leathery  leaf. 
Whenever  a  sunny  day  comes  in  winter  the 
bees  venture  out ;  and  on  all  such  days,  even 
though  it  freeze  in  the  shade,  the  crocuses  are 
open  in  the  sunshine  to  welcome  them. 

But  other  irises  are  more  complicated,  like 
the  gladiolus,  and  still  more  the  garden  irises, 
in  which  the  difference  between  the  calyx  and 
corolla  is  carried  to  its  furthest  point  in  this 
family.  The  sepals  in  truefirises  are  large  and 
brilliantly  coloured ;  they  hang  over  gracefully ; 
the  petals  are  smaller  and  erect ;  the  stigmas 
are  so  expanded  as  to  look  like  petals ;  and 
they  arch  over  the  stamens  in  a  most  peculiar 
manner.  If  you  watch  a  bee  visiting  a  garden 
iris,  you  will  see  for  yourself  the  use  of  this 
most  peculiar  arrangement ;  the  bee  lights  on 
the  bending  sepal,  and  inserts  his  head  between 
the  stigma  and  the  stamen  in  a  way  which 
renders  fertilisation  simply  inevitable.  But  the 


126       THE  STORY  OF  THE  PLANTS. 

most  curious  part  of  it  all  is  that  the  flower, 
from  the  point  of  view  of  the  bee,  resembles 
three  distinct  and  separate  blossoms ;  he  alights 
one  after  another  on  each  bending  sepal,  and 
proceeds  to  search  for  honey  as  if  in  a  new 
flower. 

Highest  of  all  the  threefold  flowers,  and  most 
wonderful  in  their  marriage  customs,  are  the 


FIG.    22. — SINGLE   FLOWER   OF  ORCHID,   WITH  THE 

PERIANTH  CUT  AWAY.  The  honey  is  in  the 
spur,  n;  the  pollen -masses  are  marked  a; 
their  gummy  base  is  at  r ;  the  stigma  at  st. 

great  group  of  orchids,  some  of  which  grow  wild 
in  our  English  meadows,  while  others  fix  them- 
selves by  short  anchoring  roots  on  the  branches 
of  trees  in  the  tropical  forests.  Many  of  these 
last  produce  the  handsomest  and  most  extra- 
ordinary flowers  in  the  world,  and  they  are 


MORE  MARRIAGE  CUSTOMS.        127 

much  cultivated  accordingly  in  hothouses  and 
conservatories.  It  would  be  quite  impossible 
for  me  to  give  you  any  account  of  the  infinite 
devices  invented  by  these  plants  to  secure 
insect-fertilisation ;  and  even  the  structure  of 
the  flower  is  so  extremely  complex  that  I  can 
hardly  undertake  to  describe  it  to  you  intel- 
ligibly; but  I  will  give  you  such  a  brief  state- 
ment of  its  chief  peculiarities  as  will  enable  you 
to  see  how  highly  it  has  been  specialised  in 
adaptation  to  insect  visits. 

The  ovary  in  orchids  is  inferior,  and  curiously 
twisted.  It  supports  six  perianth-pieces,  three 
of  which  are  sepals,  often  long  and  very  hand- 
some ;  while  two  are  petals,  often  arching  like  a 
hood  over  the  centre  of  the  flower.  The  third 
petal,  called  the  lip,  is  quite  different  in  shape 
and  appearance  from  the  other  two,  and  usually 
hangs  down  in  a  very  conspicuous  manner. 
There  are  no  visible  stamens,  to  be  recognised 
as  such ;  but  the  pollen  is  contained  in  a  pair 
of  tiny  bags  or  sacks,  close  to  the  stigma.  It 
is  united  into  two  sticky  club-shaped  lumps, 
usually  called  the  pollen-masses  (Fig.  22).  In 
other  words,  the  orchids  have  got  rid  of  all  their 
stamens  except  one,  and  even  that  one  has  united 
with  the  stigma. 

I  will  only  describe  the  mode  of  fertilisation 
of  one  of  these  plants,  the  common  English 
spotted  orchis ;  but  it  will  suffice  to  show  you 
the  extreme  ingenuity  with  which  members  of 
the  family  often  arrange  their  matrimonial 
alliances.  The  spotted  orchis  has  a  long  tube 
or  spur  at  the  base  of  its  sepals  (Fig.  22,  ri),  and 


128 


THE    STORY   OF   THE    PLANTS. 


this  spur  contains  abundant  honey.  The  pollen- 
masses  are  neatly  lodged  in  two  little  sacks  or 
pockets  near  the  stigma,  and  are  so  placed  that 
their  lower  ends  come  against  the  bee's  head  as 
he  sucks  the  honey.  These  lower  ends  (r)  are 
gummy  or  viscid,  and  if  you  press  a  straw  or 
the  point  of  a  pencil  against  them,  the  pollen- 
masses  gum  themselves  to  it  naturally,  and 
come  readily  out  of  their  sacks  as  you  withdraw 
the  pencil  (Fig.  23),  In  the  same  way,  when 


I  P 


FIG.  23. — POLLEN-MASSES  OF  AN  OBCHID,  WITH- 
DRAWN ON  A  PENCIL.  In  I,  they  have  just 
been  removed.  In  II,  they  have  dried  and 
moved  forward. 

the  bee  presses  them  with  his  head,  the  pollen- 
masses  stick  to  it,  and  he  carries  them  away  with 
him  as  he  leaves  the  flower,  Just  at  first,  the 
pollen-masses  stand  erect  on  his  forehead;  but  as 
he  flies  through  the  air,  they  dry  and  contract, 
so  that  they  come  to  incline  forward  and  out- 
ward. By  the  time  he  reaches  another  plant 
they  have  assumed  such  a  position  that  they 
are  brought  into  contact  with  the  stigma  as  he 
sucks  the  honey.  But  the  stigma  is  gummy  too, 
and  makes  the  pollen  adhere  to  it,  and  in  this 


MORE  MARRIAGE  CUSTOMS. 


129 


way  cross-fertilisation  is  rendered  almost  a  dead 
certainty.  The  result  of  these  various  clever 
dodges  is  that  the  orchids  have  become  one  of 
the  dominant  plant-families  of  the  world,  and  in 
the  tropics  usurp  many  of  the  best  and  most 
favoured  positions  (Fig.  24). 

Darwin  has  written  a  most  romantic  book  on 
the  numerous  devices  by  which  orchids  alone 
attract  insects  to  fertilise  them.  I  will  say  no 
more  of  this  family,  therefore 
— the  highest  and  strangest 
among  the  threefold  flowers 
— save  merely  to  advise  those 
who  wish  to  know  more  of 
this  curious  subject  to  look 
it  up  in  his  charming  volume. 
Instead  of  pursuing  the 
matter  at  issue  further,  I 
will  give  one  final  example 
in  an  opposite  direction. 

An  opposite  direction,  I 
say,  because  all  the  threefold 
flowers  we  have  hitherto  been 
considering  are  examples 
of  a  strict  upward  move- 
ment of  evolution.  Each  group  we  have  ex- 
amined has  been  higher  and  more  complex 
than  the  group  before  it.  But  I  will  now  show 
you  an  instance,  if  not  of  degeneracy,  at  least  of 
extreme  simplification,  which  yet  produces  in 
the  end  the  best  possible  results.  This  instance 
is  that  of  the  common  English  arum,  known  to 
children  as  cuckoo-pint  or  "  lords  and  ladies " 
(Fig.  25). 

9 


no.    24. — THE    TWO 

POLLEN-MASSES,  VERY 
MUCH  ENLARGED. 


130       THE  STORY  OF  THE  PLANTS. 

The  structure  of  the  cuckoo-pint  is  very 
peculiar.  What  looks  like  the  flower  is  not 
really  any  part  of  the  flower  at  all,  but  a  large 


FIG.  25. — THE  COMMON  ARUM,  OB  CUCKOO- 
PINT,  SHOWING  THE  SPATHE  WHICH  SUR- 
ROUNDS THE  FLOWERS,  AND  THE  SPIKE 
STICKING  UP  IN  THE  MIDDLE. 

outer  leaf  or  spathe  surrounding  a  group  of  very 
tiny  blossoms.  You  can  understand  this  leaf 
better  if  you  look  at  a  narcissus  stalk,  where 


MOKE   MAKKIAGE   CUSTOMS. 


131 


a  very  similar  leaf  is  seen  to  enclose  a  whole 
bunch  of  buds  and  opening  flowers.  Only,  in 
the  narcissus  the  spathe  is  thin,  whitish,  and 
papery,  while  in  the  cuckoo-pint  it  is  expanded, 
green,  and  purple.  Though  not  a  corolla,  it 
serves  the  same  purpose  as  a  corolla  generally 
performs  :  it  attracts  insects 
to  the  compound  flower-head. 
Inside  the  spathe  we  find 
a  curious  club-shaped  mass, 
coloured  bright  purple,  and 
standing  straight  up  in  the 
middle  of  the  head.  This  is 
the  stem  or  axis  on  which  the 
separate  little  flowers  are 
arranged.  Cut  open  the  spathe, 
and  you  will  find  these  flowers 
below  in  the  centre  (Fig.  26). 
At  first  sight  what  you  see 
will  look  like  a  lot  of  confused 
little  knobs ;  but  when  you 
gaze  closer  you  will  see  they 
separate  themselves  into  three 
groups,  which  are  the  true 
flowers.  Lowest  of  all  on  the 
stem  come  the  female  blossoms, 
without  calyx  or  corolla,  each 
consisting  of  a  single  ovary. 
Above  these  in  a  group  come  the  male  flowers, 
equally  devoid  of  calyx  or  corolla,  and  each  con- 
sisting of  a  single  stamen.  Above  these  again 
come  abortive  or  misshapen  flowers,  each  of 
which  has  been  reduced  to  a  single  downward- 
pointing  hair.  I  will  explain  first  what  is  the 


132       THE  STOKY  OF  THE  PLANTS. 

use  of  these  flowers  in  the  cuckoo-pint  as  it 
stands  to-day,  and  then  I  will  go  back  to  con- 
sider by  what  steps  the  plant  came  to  develop 
them. 

The  upper  flowers,  which  look  like  hairs,  and 
point  all  downwards,  occupy  a  place  in  the 
compound  flower-head  just  opposite  the  con- 
spicuous narrowed  part  of  the  spathe  which 
surrounds  and  encloses  them.  At  this  narrow 
point  they  form  a  sort  of  lobster-pot.  It  is  easy 
enough  for  an  insect  to  creep  down  past  them, 
but  very  difficult  or  impossible  tefTiim  to  creep 
up  in  the  opposite  direction,  as  all  the  hairs 
point  sharply  downward.  Now,  when  the 
spathe  unfolds,  large  numbers  of  a  very  small 
midge  of  a  particular  species  are  attracted  into 
it  by  the  purple  club  which  rises  like  a  barber's 
pole  in  the  middle.  If  you  cut  a  cuckoo-pint 
open  during  its  flowering  period  you  will  always 
find  a  whole  mob  of  these  wee  flies,  crawling 
about  in  it  vaguely,  and  covered  from  head  to 
foot  with  pollen.  They  have  come  from  another 
cuckoo-pint  which  they  previolisIy^vTslte^T^ari^ 
they  have  brought  the  pollen  with  them  on  their 
wings  and  bodies.  But  when  they  first  reach 
the  head,  they  find  no  pollen  there ;  the^  JgrngJ^ 
flowers  at  the  bottom  ripen  first,  and  the  midges, 
creeping  over  the  sensitive  surface  of  these,  fer- 
tilise them  with  pollen  from  the  last  plant  they 
enterdd.  Finding  nothing  to  eat,  if  they  could 
they  would  crawl  out  again ;  but  they  can't,  for 
the  lobster-pot  hairs  prevent  them.  So  they 
stop  on  perforce,  having  unwittingly  fertilised 
the  female  flowers,  but  received  themselves  as 


MORE  MABBIAGE  CUSTOMS.        133 

yet  no  reward  for  their  trouble.  By  and  by, 
however,  rfjteE-Ali  the  female  flowers  have  been 
duly  fertilise3,  tne  males'  aBove  begin  to  ripen. 
When  the  stamens  reach  maturity,  they  shower 
down  a  whole  flood  of  golden  pollen  on  the 
expectant  midges.  Then  the  midges  positively 
roll  and  revel  in  the  flood,  eating  all  they  can, 
but  at  the  same  time  covering  themselves  all 
over  with  a  dust  of  pollen-grains.  As  soon  as 
the  pollen  is  all  shed,  the  downward-pointing 
hairs  wither  away;  the  lobster-pot  ceases  to  act; 
and  tHexmi3gBsr1lre  at  liberty  to  fly  away  to 
another  plant,  where  they  similarly  begin  to 
fertilise  the  female  flowers.  Observe  that,  if 
the  stamens  were  the^jfirst  to  ripen  here,  the 
pollen  would  fall  on  the  stigmas  of  the  same 
plant,  but  that,  by  making  the  stigma£"iT6  TTTeT* 
first  to  mature,  the  cuckoo-pint  secures  for  itself 
the  desired  end  of  cross-fertilisation. 

In  this  case  it  is  an  interesting  fact  that  all 
the  stages  which  led  to  the  existing  arrangement 
of  the  flowers  still  remain  visible  in  other  plants 
for  us.  These  very  reduced  little  blossoms  of  the 
cuckoo-pint,  consisting  each  of  a  single  carpel  or 
a  single  stamen,  arejet  tl^^jscgnx^ 
feet  blossoms^ whltfliTiad  once  a  regular  calyx 
and  corolla.  Near  relations  of  the  cuckoo-pint 
live  in  Europe  and  Africa  to  this  day,  which 
recapitulate  for  us,  as  it  were,  the  various  stages 
in  its  slow  evolution.  Some,  the  oldest  in  type, 
have  a  calyx  and  corolla,  green  and  inconspicu- 
ous, with  six  stamens  inside  them,  enclosing  a 
two  or  three-celled  ovary.  These  are  still  essen- 
tially lilies  in  structure.  But  they  have  the 


134       THE  STOEY  OP  THE  PLANTS. 

flowers  clustered,  as  in  cuckoo-pint,  on  a  thick 
club-stem,  and  they  have  an  open  spathe,  which 
more  or  less  protects  them.  Our  English  sweet- 
sedge  is  still  at  this  stage  of  evolution.  The 
marsh-calla  of  Northern  Europe  and  Canada,  on 
the  other  hand,  has  a  handsome  white  spathe  to 
attract  insects,  while  its  separate  flowers,  still 
both  male  and  female  together,  have  each  six 
stamens  and  a  single  ovary.  But  they  have  lost 
their  perianth.  The  common  white  arum  or 
"calla  lily"  of  cottage  gardens  has  a  bright 
yellow  spike  in  its  midst,  and  if  you  look  at  it 
closely  you  will  see  that  this  spike  consists 
entirely  of  a  great  cluster  of  stamens,  thickly 
massed  togetherT~Tne  top  of  the  s~pike~is  entirely 
composed  of  such  golden  stamens,  but  lower 
down  you  will  find  ovaries  embedded  here  and 
there  among  them,  each  ovary  as  a  rule  sur- 
rounded by  five  or  six  stamens.  Lastly,  in  the 
cuckoo-pint  the  lower  flowers  have  lost  their  com- 
plement of  stamens  altogether,  while  the  upper 
ones  have  similarly  lost  their  ovaries ;  moreover, 
a  few  of  the  topmost  have  been  converted  into 
the  curious  lobster-pot  hairs  which  assist,  as  I 
have  shown  you,  in  the  work  of  fertilisation. 
We  have  here  a  singular  and  instructive  example 
of  what  may  be  described  as  retrograde  develop- 
ment. 

And  now  we  must  go  on  to  those  modes  of 
fertilisation  which  are  effected  by  agencies  other 
than  insects. 


CHAPTEE  IX. 

THE    WIND    AS    CAKHIER. 

ALL  flowers  do  not  depend  for  fertilisation  upon 
insects.  In  many  plants  it  is  the  wind  that 
serves  the  purpose  of  common  carrier  of  pollen 
from  blossom  to  blossom. 

Clearly,  flowers  which  lay  themselves  out  to 
be  fertilised  by  the  wind  will  not  be  likely  to 
produce  the  same  devices  as  those  which  lay 
themselves  out  to  be  fertilised  by  insects. 
Natural  selection  here  will  favour  different  quali- 
ties. Bright- coloured  petals  and  stores  of  honey 
will  not  serve  to  allure  the  unconscious  breeze ; 
such  delicate  adjustments  of  part  to  part  as  we 
saw  in  the  case  of  bee  and  blossom  will  no  longer 
be  serviceable.  What  will  most  be  needed  now 
is  quantities  of  pollen  ;  and  that  pollen  must 
hang  out  in  such  a  way  from  the  cup  as  to  be 
easily  dislodged  by  passing  breezes.  Hence 
wind-fertilised  flowers  differ  from  insect-ferti- 
lised in  the  following  particulars.  They  have 
never  brilliant  corollas  or  calyxes.  The  stamens 
are  usually  very  numerous;  they  hang  out 
freely  on  long  stalks  or  filaments ;  and  they 
quiver  in  the  wind  with  the  slightest  movement. 
On  the  other  hand,  the  stigmas  are  feathery  and 
protrude  far  from  the  flower,  so  as  to  catch  every 
passing  grain  of  pollen.  More  frequently  than 
among  the  insect-fertilised  section,  the  sexes  are 
separated  on  different  plants  or  isolated  in  dis- 
tinct masses  on  neighbouring  branches.  But 

135 


136       THE  STOKY  OF  THE  PLANTS. 

numerous  devices   occur  to  prevent  self-fertili- 
sation. 

You  must  not  suppose,  again,  that  the  wind- 
fertilised  plants  form   a   group   by   themselves, 
distinct   in   origin  from  the  insect-fertilised,  as 
Uhe   three-petalled  group  is   distinct   from   the 
five-petalled.     On  the  contrary,  wind-fertilised 
,  kinds    are    found    abundantly    in     both    great 
^groups ;  it  is  a  matter  of  habit ;  so  much  so  that 
*  sometimes  a  type  has  taken  first  to  insect-fertili- 
sation and  then  to  wind-fertilisation,  with  com- 
paratively   slight    differences     in    its    external 
appearance.     Closely  related  plants  often  differ 
immensely  in  their  marriage  customs ;  each  has 
varied  in  the  way  that  best  suited  itself,  accord- 
ing as  insects  or  breezes  happened  to  serve  it 
most  readily.     In   my  own  opinion  all  wind- 
fertilised  plants  are  the  descendants  of  insect- 
fertilised  ancestors ;  but  I  do  not  know  whether 
in  this  belief  my  ideas  would  be  accepted  by 
most  modern  botanists. 

As  a  first  example  of  wind-fertilised  flowers, 
I  will  take  the  common  dog's  mercury,  a  well- 
known  English  wayside  flower,  frequent  in 
copses  and  hedgerows,  and  one  of  the  very 
earliest  to  blossom  in  spring.  In  this  species 
the  males  and  females  grow  on  senarate  plants. 
They  have  each  a  calyx  of  three  sepals  (two 
more  being  suppressed,  for  they  belong  by 
origin  to  the  fivefold  division).  The  males  have 
ten  or  twelve  stamens  apiece,  which  hang  out 
freely  with  long  stalks  to  the  breeze.  The 
females  have  a  two-chambered  ovary,  with 
rudiments  or  relics  of  some  two  or  three 


ttfiE   WIND   AS    CARRIED. 


137 


stamens  by  its  side,  showing  that  they  are 
descended  from  earlier  combined  rnale-and- 
female  ancestors.  The  relics,  however,  consist 
of  mere  empty  stalks  or  filaments,  without  any 
pollen-sacks.  Of  course  there  are  no  petals. 
Male  and  female  plants  grow  in  little  groups 
not  far  from  one  another  ;  and  the  pollen,  which 
is  dry  and  dusty,  is  carried  by  the  wind  from 
the  hanging  stamens  of  the  males  to  the  large 
and  salient  stigma  of 
the  female  flowers. 
A  still  better  ex- 
ample of  a  wind- 
fertilised  blossom  is 
afforded  us  by  the 
common  English 
salad  -  burnet,  a 
pretty  little  weed, 
very  frequent  on 
close-cropped  chalk 
downs  (Fig.  27). 
Here  the  individual 
flowers  are  ex- 
tremely small,  and 
they  are  crowded 
into  a  sort  of  mop- 
like  head  at  the  top  of  the  stem.  They  have  lost 
their  petals,  which  are  now  of  no  use  to  thenf; 
but  they  retain  a  calyx  of  four  sepals,  to  represent 
the  original  five  still  found  among  their  relations. 
For  salad-burnet,  in  spite  of  its  inconspicuous- 
ness,  belongs  to  the  family  of  the  roses,  and  we 
can  still  trace  in  this  order  a  regular  gradation 
from  handsome  flowers  like  the  dog-rose,  through 


FIG.  27. — A,  MALE,  AND  B,  FEMALE 
FLOWER  OF  SALAD-BURNET,  VERY 
MUCH  MAGNIFIED.  The  floWGIS 

grow  together  in  little  tassel- 
like  heads. 


138  THE  STORY  OF  THE  PLANTS. 

smaller  and  smaller  blossoms  like  the  strawberry 
and  the  potentilla,  to  green  petalless  types  like 
lady's-mantle  and  parsley-piert,  or,  last  of  all,  to 
wind-fertilised  blossoms  like  those  of  the  salad- 
burnet.  In  the  male  flowers  the  very  numerous 
stamens  hang  out  on  long  thread-like  stalks 
from  the  wee  green  cup,  so  that  the  wind  may 
readily  catch  and  carry  the  pollen :  in  the 
female  blossoms  the  stigma  is  divided  into 
plume-like  brushes,  which  readily  entrap  any 
passing  pollen-grain.  Moreover,  though  both 
kinds  of  flower  grow  on  the  same  head,  the 
females  are  mostly  at  the  top  of  the  bunch,  and 
the  males  below  them.  This  makes  it  difficult 
for  the  pollen  from  the  same  head  to  fertilise  the 
females,  as  it  would  easily  do  if  the  males  were 
at  the  top.  Nor  is  that  all ;  the  female  flowers 
open  first  on  each  head,  and  hang  out  their 
pretty  feathery  stigmas  to  the  breeze  that  bends 
the  stem  ;  as  soon  as  they  have  been  fertilised 
from  a  neighbour  plant,  the  males  in  turn  begin 
to  open,  and  shed  their  pollen  for  the  use  of 
other  flowers.  In  salad-burnet,  however,  the 
division  of  the  sexes  into  separate  flowers  has 
not  become  a  quite  fixed  habit ;  for,  though 
most  of  the  blossoms  are  either  maleor  female 
only,  as  shown  in  the  figure,  we  often  find  a  cup 
here  and  there  which  contains  both  stamens  and 
pistil  together. 

I  have  already  told  you  that  in  many  plants 
the  calyx  helps  the  corolla  as  an  advertisement 
for  insects ;  and  sometimes,  as  in  the  marsh- 
marigold  and  the  various  anemones,  where  there 
are  no  petals  at  all,  it  becomes  so  brilliant  as  to 


THE   WIND   AS    CAKRIEK.  139 

be  mistaken  for  petals  by  all  but  botanists.  One 
way  in  which  such  a  substitution  often  happens 
is  shown  us  by  the 
great  burnet,  which 
is  a  close  relation  of 
thesalad-burnet.  This 
plant,  after  having 
acquired  the  habit  of 
wind-fertilisation,  has 
taken  again  at  last 
to  insect  marriage. 
Having  lost  its  petals, 
however,  it  can't 
easily  redevelop  them ; 
30  it  has  had  instead 
to  make  its  calyx 
purple.  The  plant  as 
a  whole  closely  re- 
sembles the  salad- 
burnet ;  but  the 
flowers  are  rather 
different ;  the  stamens 
no  longer  hang  out 
of  the  calyx ;  the 
calyx  cup  is  more 
tubular ;  and  the 
stigma  is  shortened 
to  a  little  sticky  knob, 
instead  of  being 
divided  into  feathery 
fringes.  These  dif- 
ferences are  all  very  characteristic  of  the  con- 
trast between  wind  and  insect-fertilisation. 
The  common  nettle  supplies  us  with  an  excel- 


140  THE  STOBY  OF  THE  PLANTS. 

lent  example  of  another  form  of  wind-fertilisa- 
tion, carried  to  a  still  higher  pitch  of  develop- 
ment. Here  the  sexes  grow  on  different  plants, 
and  the  flowers  are  tiny,  green,  and  inconspicu- 
ous. The  males  consist  of  a  calyx  of  four  sepals, 
each  sepal  with  a  stamen  curiously  caught  under 
it  during  the  immature  stage.  But  as  soon  as 
they  ripen  they  burst  out  elastically,  and  shoot 
their  pollen  into  the  air  around  them.  In  this 
case,  and  in  many  like  it,  the  plant  itself  helps 
the  wind,  as  it  were,  to  disseminate  its  pollen. 

The  common  English  bur-reed  is  a  waterside 
plant  of  great  beauty  which  shows  us  another 
interesting  instance  of  wind-fertilisation  in  an 
advanced  condition  (Fig.  28).  Here  the  sepa- 
rate flowers  are  very  much  reduced — as  simple, 
in  fact,  as  those  of  the  cuckoo-pint.  The  males 
consist  of  nothing  but  stamens,  gathered  in  close 
globular  heads,  with  a  few  small  scales  inter- 
spersed among  them,  which  seem  to  represent 
the  last  relics  of  a  calyx.  The  females  are  made 
up  of  single  ovaries,  each  surrounded  by  three 
or  six  scales,  still  forming  a  simple  rudimentary 
calyx.  They,  too,  are  clustered  in  round  heads 
or  masses  on  antler-like  branches.  The  plant 
belongs  to  the  threefold  group,  and  represents 
a  very  degenerate  descendant  of  a  primitive 
ancestor  something  like  the  arrowhead  already 
described  in  the  last  chapter.  But  the  arrange- 
ment of  the  heads  on  the  stem  is  very  interest- 
ing. The  balls  at  the  top  are  entirely  composed 
of  male  flowers  ;  those  at  the  bottom  are  exclu- 
sively female.  The  female  flowers  ripen  first, 
and  receive  pollen  by  aid  of  the  wind  from  some 


THE   WIND   AS   CAKKIEK.  141 

other  plant  that  grows  close  by  them.  As  soon 
as  they  have  begun  to  set  their  seeds  the 
stigmas  wither,  and  then  the  male  flowers  open 
in  a  bright  yellow  mass,  the  stalks  of  their 
stamens  lengthening  out  as  they  do  so,  and 
allowing  the  wind  to  carry  the  pollen  freely. 
Here,  although  the  males  are  above,  the  pecu- 
liar arrangement  by  which  the  females  ripen 
first  makes  it  practically  impossible  for  the 
flowers  to  be  fertilised  by  pollen  from  their 
immediate  neighbours. 

The  devices  for  wind-fertilisation,  however, 
are  on  the  whole  less  interesting  than  those  for 
insect-fertilisation,  so  I  shall  devote  little  more 
space  to  describing  them.  I  will  only  add  that 
two  great  classes  of  plants  are  habitually  wind- 
fertilised  :  one  includes  the  majority  of  forest 
trees ;  the  other  includes  the  grasses,  sedges, 
and  many  other  common  meadow  plants. 

The  wind-fertilised  forest  trees  belong  for  the 
most  part  to  the  fivefold  group,  and  have  their 
flowers,  as  a  rule,  clustered  together  into  hang- 
ing and  pendulous  bunches,  which  we  call  cat- 
kins. It  is  obvious  why  trees  should  have 
adopted  this  mode  of  fertilisation,  because  they 
grow  high,  and  it  is  easy  for  the  wind  to  move 
freely  through  them.  For  this  reason,  most 
catkin-bearing  trees  flower  in  early  spring,  when 
winds  are  high,  and  when  the  trees  are  leafless ; 
because  then  the  foliage  doesn't  interfere  with 
the  proper  carnage  of  the  pollen.  In  summer 
the  leaves  would  get  in  the  way ;  the  pollen 
would  fall  on  them ;  and  the  stigmas  would  be 
hidden.  Most  catkins  are  long,  and  easily 


142       THE  STOKY  OF  THE  PLANTS. 

moved  by  the  wind ;  they  have  numerous 
flowers  in  each,  and  they  shake  out  enormous 
quantities  of  pollen.  This  you  can  see  for  your- 
self by  shaking  a  hazel  branch  in  the  flowering 
season,  when  you  will  find  yourself  covered  by 
a  perfect  shower  of  pollen. 

In  hazel  (Fig.  29)  the  male  and  female 
flowers  grow  on  the  same  tree,  but  are  most 
different  to  look  at.  You  would  hardly  take 


1 


FIG.  29. — FLOWERS  OP  THE  HAZEL.  I,  a  single 
male  flower,  removed  from  a  catkin.  II, 
a  pair  of  female  flowers.  Ill,  a  female 
catkin. 

them  for  corresponding  parts  of  the  same 
species.  The  male  flowers  are  grouped  in  long 
sausage-shaped  catkins,  each  blossom  covered 
with  a  tiny  brown  scale,  and  all  arranged  like 
tiles  on  a  roof  against  the  cold  of  winter.  There 
are  about  eight  stamens  to  each  blossom,  with 
little  trace  of  a  calyx  or  corolla.  But  the  females 
are  grouped  in  funny  little  buds,  like  crimson 
tufts,  well  protected  by  scales ;  they  consist  of 
the  future  hazel-nut,  with  a  red  style  and 
feathery  stigma  projecting  above  to  catch  the 
pollen.  Here  the  flowers  are  very  little  like 


THE    WIND   AS    CARRIER.  143 

the  regular  types  with  which  we  are  familiar; 
yet  intermediate  cases  help  to  bridge  over  the 
gap  for  us. 

For  example,  in  the  alder  we  get  a  type  which 
seems  to  stand  half-way  between  the  nettle  and 
the  hazel  (so  far,  I  mean,  as  the  arrangement  of 
the  flower  is  concerned,  for  otherwise  the  nettle 
belongs  to  a  quite  different  family).  The  male 
and  female  catkins  of  the  alder  grow  on  the 
same  tree ;  the  males  consist  of  numerous 
clustered  flowers,  three  together  under  a  scale, 
which  nevertheless,  when  we  take  the  trouble  to 
pick  them  out  and  examine  them  with  a  pocket  - 
lens,  are  seen  to  resemble  very  closely  the  male 
flowers  of  the  nettle.  Each  consists  of  a  four- 
lobed  calyx,  with  four  stamens  opposite  the 
sepals.  The  female  flowers  have  degenerated 
still  further,  and  consist  of  little  more  than  a 
scale  and  an  ovary. 

Other  well-known  wind-fertilised,  catkin-bear- 
ing trees  are  the  oak,  the  beech,  the  birch,  and 
the  hornbeam.  But  the  willows,  though  they 
bear  catkins,  and  were  once  no  doubt  wind- 
fertilised,  have  now  returned  once  more  to 
insect-fertilisation,  as  you  can  easily  convince 
yourself  if  you  stand  under  a  willow  tree  in 
early  spring,  when  you  will  hear  all  the  branches 
alive  with  the  buzzing  of  bees,  both  wild  and 
domestic.  Nevertheless,  the  willow,  having 
once  lost  its  petals,  has  been  unable  to  develop 
them  again.  Still,  its  catkins  are  far  hand- 
somer and  more  conspicuous  than  those  of  its 
wind-fertilised  cousins,  owing  to  the  pretty 
white  scales  of  the  female  bunches,  and  the 


144       THE  STORY  OF  THE  PLANTS. 

numerous  bright  yellow  stamens  of  the  males. 
It  is  this  that  causes  them  to  be  used  for 
"  palm "  in  churches  on  Palm  Sunday.  The 
male  and  female  catkins  grow  on  different  trees, 
so  as  to  ensure  cross-fertilisation,  and  the  dif- 
ference between  the  two  forms  is  greater  per- 
haps than  in  almost  any  other  plant,  the  males 
consisting  of  two  showy  stamens  behind  a 
winged  scale,  and  the  females  of  a  peculiar 
woolly-looking  ovary. 

Even  more  important  is  the  great  wind-ferti- 
lised group  of  the  grasses,  to  which  belong  by 
far  the  most  useful  food-plants  of  man,  such  as 
wheat,  rice,  barley,  Indian  corn,  and  millet. 

Grasses  are  for  the  most  part  plants  of  the 
open  wind-swept  plains,  and  they  seem  natu- 
rally to  take  therefore  to  wind-fertilisation. 
Their  flowers  are  generally  small,  clustered  into 
light  spikes  or  waving  panicles,  and  hung  out 
freely  to  the  breeze  on  slender  and  very  movable 
stems,  so  as  to  yield  their  pollen  to  every  breath 
of  air  that  passes.  Moreover,  the  plants  as  a 
whole  are  slender  and  waving,  so  that  they  bend 
before  the  breeze  in  the  mass,  as  one  often  sees 
in  a  meadow  or  cornfield.  Thus  the  grasses  are 
almost  the  pure  type  of  wind-fertilised  plants; 
certainly  they  have  carried  further  than  any 
other  race  the  devices  which  render  wind- 
fertilisation  more  certain. 

On  this  account  they  are  so  complicated  and 
varied  that  I  will  not  attempt  to  describe  them 
in  detail.  I  will  only  say  that  grasses  are 
| descendants  of  the  threefold  flowers,  and  in  all 
probability  degenerate  lilies.  Their  individual 


THE  WIND  AS  CAKBIER, 


145 


blossoms  usually  consist  of  a  very  degraded 
calyx  (d  and  e)  of  two  sepals  (one  of  which 
represents  a  pair  that  have  coalesced,  Fig.  30). 
Inside  these  sepals  come  two  very  minute  white 
petals  (c  and  c) ;  the  third  has  disappeared, 
owing  to  pressure  one-sidedly.  The  petals  can 


FIG.     30. — A     FLOWER      OF 
WHEAT,    WITH    ITS    PARTS 

DIVIDED  :  a,  the  carpel 
and  stigmas ;  b,  the 
stamens  ;  c,  the  petals, 
very  minute ;  d  and  e, 
the  calyx. 


FIG.  31. — FLOWER  OF  WHEAT, 
WITH  THE  CALYX  OF  TWO 
CHAFFY  SCALES  REMOVED. 

This  shows  the  arrange- 
ment of  petals,  stamens, 
and  ovary. 


scarcely  be  seen  without  the  aid  of  a  pocket- 
lens.  Next  come  three  stamens  (b),  the  only 
part  of  the  flower  which  still  preserves  the 
original  threefold  arrangement.  Last  of  all  we 
get  the  ovary  (a),  of  one  carpel,  one  seeded,  but 
with  two  feathery  stigmas,  which  were  once 
10 


146  THE  STORY  OP  THE  PLANTS, 

three.  In  a  very  few  large  grasses,  such  as  the 
bamboos,  the  threefold  arrangement  is  much 
more  conspicuous.  As  a  rule  the  stamens  of 
grasses  hang  out  freely  to  the  wind,  and  the 
stigmas  are  feathery  and  most  graceful  in  out- 
line (Fig.  31).  The  flowers  are  usually  collected 
in  spikes  like  that  of  wheat,  or  in  loose  clusters 
like  oats ;  they  frequently  hang  over  in  pen- 
dulous bunches.  Their  success  may  be  gathered 
from  the  fact  that  almost  all  the  great  plains  in 
the  world,  such  as  the  American  prairies,  the 
Pampas,  and  the  Steppes,  are  covered  with 
grasses  ;  while  even  in  hilly  countries  the  valleys 
and  downs  are  also  largely  clad  with  smaller 
and  more  delicate  species.  No  plants  assume 
so  great  a  variety  of  divergent  forms ;  the  total 
number  of  kinds  of  grasses  can  hardly  be 
estimated ;  in  Britain  alone  we  have  more  than 
a  hundred  native  species. 

I  will  give  no  further  examples  of  wind- 
fertilised  flowers.  If  you  look  for  yourself  you 
can  find  dozens  on  all  sides  in  the  fields  around 
you.  They  may  almost  always  be  recognised 
by  these  two  marked  features  of  the  hanging 
stamens  and  the  feathery  stigma. 

Before  I  pass  on  to  another  subject,  however, 
I  ought  to  mention  that  by  no  means  all  flowers 
are  regularly  cross- fertilised.  There  are  some 
degraded  types  in  which  self-fertilisation  has 
become  habitual.  In  these  plants,  which  are 
usually  poor  and  feeble  weeds  like  groundsel 
and  shepherd's  purse,  the  stamens  bend  round 
so  as  to  impregnate  the  pistil  in  the  same 
blossom.  In  other  less  degraded  cases  the 


HOW   FLOWEKS    CLUB    TOGETHER.  147 

flower  is  occasionally  cross-fertilised  by  insect 
visits  ;  but  if  no  insect  turns  up  in  time,  the 
stamens,  even  in  handsome  and  attractive 
blossoms,  often  bend  round  and  impregnate  the 
pistil.  A  very  good  example  of  this  is  seen  in  * 
our  smaller  English  mallow,  which  has  large 
mauve  flowers  to  attract  insects  ;  but  should 
none  come  to  visit  it,  the  stamens  and  stigmas 
at  last  intertwine,  and  self -fertilisation  takes 
place,  for  want  of  better.  Still,  as  a  general 
rule,  it  holds  good  that  self-fertilisation  belongs 
to  scrubby  and  degraded  plants  ;  it  is  only 
adopted  as  a  last  resort  when  all  other  means 
fail  by  the  superior  species. 


CHAPTEE  X. 

HOW  FLOWERS  CLUB  TOGETHER. 

IN  the  preceding  chapters  I  have  dealt  for  the 
most  part  with  individual  flowers ;  I  have 
spoken  of  them  separately,  and  of  the  work 
they  do  in  getting  the  seeds  set.  Incidentally, 
however,  it  has  been  necessary  at  times  to 
touch  slightly  upon  the  way  they  often  mass 
themselves  into  heads  or  clusters  for  various 
purposes ;  and  we  must  now  begin  to  consider 
more  seriously  the  origin  and  nature  of  these 
co-operative  societies. 

Very  large  flowers,  like  the  water-lily,  the 
tulip,  the  magnolia,  the  daffodil,  are  usually 
solitary  ;  they  suffice  by  themselves  to  attract 
in  sufficient  numbers  the  fertilising  insects. 


148  THE    STOEY   OF   THE   PLANTS. 

.  But  smaller  flowers  often  find  it  pays  them 
better  to  group  themselves  into  big  spikes  or 
masses,  as  one  sees,  for  example,  in  the  fox- 
glove and  the  lilac.  Such  an  arrangement 
makes  the  mass  more  conspicuous,  and  it  also 
induces  the  insect,  when  he  comes,  to  fertilise 
at  a  single  visit  a  large  number  of  distinct 
blossoms.  It  is  a  mutual  convenience  ;  for  the 
bee  or  butterfly,  it  saves  valuable  time ;  for  the 
splant,  it  ensures  more  prompt  and  certain 
fertilisation.  In  many  families,  therefore,  we 
can  trace  a  regular  gradation  between  large  and 
almost  solitary  flowers,  through  smaller  and 
somewhat  clustered  flowers,  to  very  small  and 
.  comparatively  crowded  flowers.  Thus  the 
largest  lilies  are  usually  solitary  or  grow  at 
best  three  or  four  together,  like  the  lilium 
auratum ;  in  the  tuberose  and  asphodel,  where 
the  individual  blossoms  are  smaller,  they  are 
gathered  together  in  big  upright  spikes  ;  in  the 
hyacinth,  the  clustering  is  closer  still;  while 
in  wild  garlic,  grape-hyacinth,  and  star-of- 
Bethlehem,  the  arrangement  assumes  the  form 
of  a  flat-topped  bunch  or  a  globular  cluster.  Of 
course,  small  flowers  are  sometimes  solitary, 
and  large  ones  sometimes  clustered ;  but  as  a 
general  rule  the  tendency  is  for  the  big  blossoms 
to  trust  to  their  own  individual  attractions,  and 
for  the  little  ones  to  feel  that  union  is  strength, 
and  to  organise  accordingly. 

Botanists  have  invented  many  technical 
names  for  various  groupings  of  flowers  in  par- 
ticular fashions,  with  most  of  which  I  will  not 
trouble  you.  It  will  be  sufficient  to  recall 


HOW  FLOWERS  CLUB  TOGETHER.      149 

mentally  the  very  different  way  in  which  the 
flowers  are  arranged  in  the  lily-of-the-valley,  the 
foxglove,  the  Solomon's  seal,  the  heath,  the 
scabious,  the  cowslip,  the  sweet-william,  the 
forget-me-not,  in  order  to  see  what  variety 
natural  selection  has  produced  in  all  these 
matters.  Two  instances  must  serve  to  illustrate 
their  mode  of  action.  The  foxglove  grows  in 
hedgerows  and  thickets,  and  turns  its  one-sided 
spike  towards  the  sun  and  the  open ;  its  flowers 
open  regularly  from  below  upward,  and  are 
fertilised  by  bees,  who  enter  the  blossoms,  and 
whose  body  is  beautifully  adapted  to  come  in 
contact,  first  with  the  stamens,  and  later  with 
the  stigma.  (Examine  this  familiar  flower  for 
yourself  in  the  proper  season.)  In  the  forget- 
me-not,  on  the  other  hand,  the  unopened  flowers 
are  coiled  up  like  a  scorpion's  tail ;  but  as  each 
one  opens,  the  stem  below  it  lengthens  and 
unrolls,  so  that  at  each  moment  the  two  or 
three  flowers  just  ready  for  fertilisation  are 
displayed  conspicuously  at  the  top  of  the 
apparent  cluster. 

There  are  two  forms  of  cluster,  however,  so 
specially  important  that  I  cannot  pass  them 
over  here  without  some  words  of  explanation. 
These  are  the  umbel  and  the  head,  both  of 
frequent  occurrence.  An  umbel  is  a  cluster  in 
which  the  flowers,  standing  on  separate  stalks, 
reach  at  last  the  same  level,  so  as  to  form  a 
flat-topped  mass,  like  the  surface  of  a  table. 
An  immense  family  of  plants  has  very  small 
flowers  arranged  in  such  an  order ;  they  are 
known  as  umbellates,  and  they  include  hemlock, 


150       THE  STOKY  OF  THE  PLANTS. 

fool's     parsley,     cow-parsnip,     carrot,    chervil, 
celery,     angelica,     and    samphire.      In    other 


FIG.    32. — CLUSTEBS    OF    FLOWERS.       I,    Spike   of 

mercury,  green,  wind-fertilised.  II,  panicle 
of  a  grass  (brome),  green,  wind-fertilised. 
Ill,  head  of  Dutch  clover,  the  upper  flowers 
unvisited  as  yet  by  insects;  the  lower  fer- 
tilised, and  turning  down  to  make  room  for 
their  neighbours. 

families  the  same  form  of  cluster  is  seen 


HOW   FLOWERS    CLUB    TOGETHEE.  151 

ivy  and  garlic.  A  head,  again,  is  a  cluster  in 
which  the  individual  flowers  are  set  close  on 
very  short  stalks  or  none  at  all  in  a  round  ball 
or  a  circle.  Clover  and  scabious  are  excellent 
examples  of  this  sort  of  co-operation. 

If  you  examine  a  head  of  common  white  Dutch 
clover   (Fig.  32,  iii.),  you  will  see  for  yourself 
that  it  is  not,  as  you  might  suppose,  a  single 
flower,  but  a  thick  mass  of  small  white  pea-like 
blossoms,  each  on  a  stalk  of  its  own,  and  each 
provided    with    calyx,    corolla,    stamens,    and 
pistil.     They  are  fertilised  by  bees  ;  and  as  soon  I 
as  the  bee  has  impregnated   each  blossom,  it) 
turns  down  and  closes  over,  so  as  to  warn  the 
future  visitor   that   he    has   nothing  to  expect) 
there.     The  flowers  open  from  below  and  with- 
out, upward  and  inward ;  and  there  is  always  a 
broad   line   between   the    rifled    and    fertilised 
flowers,  which  hang  down   as  if   retired   from 
business,  and  the  fresh  and  upstanding  virgin 
blossoms,  which  court  the  bees  with  their  bright, 
corollas.     Sometimes  you  will  find  a  head  of 
clover  in  which  all  the  flowers  save  one  have  ^ 
already  been  fertilised  ;  and  this  one,  a  solitary  * 
old  maid  as  it  were,  stands  up  in  the  centre  still 
waiting  for  the  bees  to  come  and  fertilise  it. 

By  far  the  most  interesting  form  of  head, 
however,  is  that  which  occurs  in  the  daisy,  the 
sunflower,  the  dandelion,  and  their  allies,  where 
the  club  or  co-operative  society  of  united  blos- 
soms so  closely  simulates  a  single  flower  as  to 
be  universally  mistaken  for  one  by  all  but 
botanical  observers.  To  the  world  at  large  a 
daisy  or  a  dahlia  is  simply  a  flower ;  in  reality 


152       THE  STORY  OF  THE  PLANTS. 

it  is  nothing  of  the  sort,  but  a  city  or  com- 
munity   of    distinct    flowers,    differing    widely 
from  one  another  in  structure  and  function,  but 
all  banded  together  in  due  subordination  for  the 
purpose  of  effecting  a  common  object.     There  is 
a  vast  and  very  varied  family  of  such  united 
flowers,  known  as  the  composites ;  it  stands  at 
^    the   head   of    the   fivefold    group   of    flowering 
-?  .plantisTas  the  orchids  stand  at  the  head  of  the 


FIG.  33. — SINGLE   FLORET  FIG.     34. — SINGLE     FLORET 

FROM     THE     CENTRE    OF  FROM    THE   CENTRE    OF   A 

A   DAISY.  DAISY,  WITH  THE  COROLLA 

OPENED,  MUCH  ENLARGED. 

threefold  ;  and  it  is  so  widely  spread,  it  includes 
so  large  a  proportion  of  the  best-known  plants, 
and  it  fills  so  great  a  space  in  the  vegetable 
world  generally,  that  I  cannot  possibly  pass  it 
over  even  in  so  brief  and  hasty  a  history  as  this 
of  the  development  of  plants  on  the  surface  of 
our  planet. 

If  you  pick  a  daisy    you  will  think  at  first 
sight  it  is  a  single  flower.      But  if  you   look 


HOW   FLOWEKS    CLUB    TOGETHER. 


153 


closer  into  it  you  will  see  it  is  really  a  great 
group  of  flowers— a  compound  flower-head,  com- 
posed of  many  dozen  distinct  blossoms  or  florets, 
as  we  call  them  (Fig.  33).  These,  however,  are 
not  all  alike.  The  florets  in  the  centre,  which 
you  took  no  doubt  at  first  sight  for  the  stamens 
and  pistils,  are  small  yellow  tubular  blossoms, 
each  with  a  combined  corolla  of  five  lobes,  little 
or  no  visible  calyx,  five 
stamens  united  in  a  ring 
round  the  style,  and  a 
pistil  consisting  of  an  in- 
ferior ovary,  with  a  style 
divided  above  into  a  two- 
fold stigma  (Fig.  34) .  Here 
we  have  clear  evidence 
that  the  plant  belongs  by 
origin  to  the  five-petalled 
group ;  it  rather  resembles 
the  harebell,  in  the  plan 
of  its  flower,  on  a  much 
smaller  scale  ;  but  it  has 
almost  lost  all  trace  of  a 
separate  calyx,  it  has  its 
five  petals  united  into  a  FIG.  35. 
tubular  corolla,  it  has  still 
its  original  five  stamens, 
but  its  carpels  are  now 
reduced  to  one,  with  a 
single  seed,  though  traces  of  an  earlier  inter- 
mediate stage,  when  the  carpels  were  two, 
remains  even  yet  in  the  divided  stigma. 

So  much  for  the  inner  flowers  or  florets  in  the 
daisy.     The  outer  ones,  which  you  took  at  first 


-SINGLE  FLORET 
FROM  THE  RAY  OF  A  DAISY, 
PINK  AND  WHITE,  WITH 
AN  OVARY,  BUT  NO  STA- 
MENS. 


; 


154       THE  STOKY  OF  THE  PLANTS. 

no  doubt  for  petals,  are  very  different  indeed 
from  these  central  blossoms.  They  have  an 
extremely  curious  long,  strap-shaped  corolla 
(Fig.  35),  open  down  the  side,  but  tubular  at  its 
base,  as  if  it  had  been  split  through  the  greater 
part  of  its  length  by  a  sharp  penknife.  Instead 
of  being  yellow,  too,  these  outer  florets  are 
white,  slightly  tinged  with  pink,  and  they  form 
the  largest  and  most  attractive  part  of  the  whole 
flower-head.  Furthermore,  they  are  female 
only  ;  they  have  a  style  and  ovary,  but  no 
[stamens.  Clearly,  we  have  here  a  flower-head 
with  numerous  unlike  flowers,  which  at  once 
suggests  the  idea  of  a  division  of  labour  between 
the  component  members.  How  this  division 
works  we  shall  see  in  the  sequel. 

The  best  way  to  see  it  is  to  follow  up  in  detail 
the  evolution  of  the  daisy  and  the  other  com- 
posifeT^tfom  an  earlier  ancestor.  We  saw 
already  how  the  petals  combined  in  the  harebell 
and  many  other  flowers  so  as  to  form  a  tubular 
corolla.  A  purple  flower  of  some  such  type 
seems  to  have  been  the  starting-point  for  the 
development  of  the  great  composite  family.  The 
individual  blossoms  in  the  common  ancestral 
form  seem  to  have  been  small  and  numerous ; 
and,  as  often  happens  with  small  flowers,  they 
found  that  by  grouping  themselves  together  in 
a  flat  head  they  succeeded  much  better  in 
attracting  the  attention  of  the  fertilising  insects. 
Many  other  tubular  flowers  that  are  not  com- 
posites have  independently  hit  upon  the  same 
device  ;  such  are  the  scabious,  the  devil' s-bit, 
the  sheep's-bit,  and  the  rampion.  But  these 


HOW    FLOWEES    CLUB    TOGETHEK.  155 

flowers  differ  from  the  true  composites  in  two 
or  three  particulars.  In  the  first  place,  each 
tiny  flower  has  a  distinct  green  calyx,  of  five 
sepals ;  while  the  composites  have  none,  or  at 
least  a  degraded  one.  In  the  second  place,  the. 
stamens  are  free,  while  in  the  composites  they 
have  united  in  a  ring  or  cylinder.  In  the  third 
place,  the  ovary  is  divided  into  from  two  to  five 
cells,  a  reminiscence  of  the  original  five  distinct 
carpels ;  whereas  in  the  composites  t?ie  ovary  is 
always  single  and  one-seeded.  In  all  these 
respects,  therefore,  the  composites  are  later  and 
more  advanced  types  than,  say,  the  sheep's-bit, 
which  is  a  flower-head  composed  of  very  tiny 
harebells. 

The  composites,  then,  started  with  florets 
which  had  little  or  no  calyx,  th£^sepal£jiaving 
been  converted  into  tiny  feathery Tiairs,  used  to 
float  the  fruit"  (aS'  in  thistledow~ri~~ahd  dandelion) , 
about  which  we  shall  have  more  to  say  in  a 
future  chapter.  They  had  a  corolla  of  five 
purple  petals,  combined  into  a  single  tube. 
Inside  this  again  came  five  united  stamens,  and 
in  the  midst  of  all  an  inferior  ovary  with  a 
divided  stigma.  Hundreds  of  different  kinds  of 
composites  now  existing  on  the  earth  retain  to 
this  day,  in  the  midst  of  the  greatest  external 
diversity,  these  essential  features,  or  the  greater 
part  of  them. 

You  may  take  the  thistle  as  a  good  example  of 
the  composite  flowers  in  an  early  and  relatively 
simple  stage  of  development  (Fig.  36).  Here 
the  whole  flower-head  resembles  a  single  large 
purple  blossom,  To  increase  the  resemblance, 


156 


THE    STOKY   OF   THE    PLANTS. 


it  has  below  it  what  seems  at  first  sight  to  be  a 
big  green  calyx  of  very  numerous  sepals.  What 
is  this  deceptive  object  ?  Well,  it  is  called  an 
involucre,  and  it  really  acts  to  the  compound 

flower-head  very 
much  as  the  calyx 
acts  to  the  single 
blossom.  The 
florets  having  got 
rid  of  their  sepa- 
rate calyxes,  the 
flower-head  pro- 
vides itself  with 
a  cup  of  leaves 
(technically  called 
bracts),  which  pro- 
tect the  unopened 
head  in  its  early 
stages,  and  serve 
to  keep  off  ants 
or  other  creeping 
insects  exactly  as 
a  calyx  does  for 
the  single  flower. 
Inside  this  invo- 
lucre, again,  all 
the  florets  of  the 
thistle  are  equal 
and  similar.  Each 
has  a  tiny  calyx, 
hardly  recognis- 
able as  such,  made  up  of  feathery  hairs  which 
cap  the  inferior  ovary.  Within  this  fallacious 
calyx,  once  more,  the  floret  has  a  purple  corolla 


TIG.  36. — FLOWER  -  HEAD  OP  A 
THISTLE,  CONSISTING  OF  VERY 
NUMEROUS  PURPLE  FLORETS, 
ALL  EQUAL  AND  SIMILAR. 


HOW  FLOWEBS   CLUB   TOGETHER.  157 

of  five  petals,  united  into  a  tube.     Then  come 
the  five  united  stamens,  and  the  pistil  with  its 
divided  stigma.    This  is  the  simplest  and  central  -, 
form  of  composite,  from  which  the  others  are 
descended  with  various  modifications. 

To  this  central  type  belong  a  large  number  of 
well-known  plants,  both  useful  and  ornamental, 
though  more  particularly  deleterious.  Among 
them  may  be  mentioned  the  various  thistles, 
such  as  the  common  thistle,  the  milk  thistle,  the 
Scotch  thistle,  and  so  forth,  most  of  which  have 
their  involucres,  and  often  their  leaves  as  well, 
extremely  prickly,  so  as  to  ward  off  the  attacks 
of  goats  and  cattle.  The  burdock,  the  artichoke, 
the  saw-wort,  and  the  globe-thistle  also  belong  to 
the  same  central  division.  Among  these  earlier 
composites,  however,  there  is  one  group,  that  of 
the  centauries,  which  leads  us  gradually  on  to 
the  next  division.  Our  commonest  centaury  in 
Britain  (known  to  boys  as  hardheads)  has  all  the 
florets  equal  and  similar,  and  looks  in  the  flower 
very  much  like  a  thistle.  But  one  of  its  forms, 
and  most  of  the  cultivated  garden  centauries, 
have  the  outer  florets  much  larger  and  more 
broadly  open  than  the  central  ones,  so  that  they 
form  an  external  petal-like  row,  which  adds 
greatly  to  the  attractiveness  of  the  entire  flower- 
head.  Of  this  type,  the  common  blue  cornflower 
is  a  familiar  example.  Clearly  the  plant  has 
here  developed  the  outer  florets  more  than  the 
inner  ones  in  order  to  make  them  act  as  extra 
special  attractions  to  the  insect  fertilisers. 

The  more  familiar  type  of  composites  so  much 
cultivated  in  gardens  carries  these  tactics  a  step 


158  THE  STOKY  OF  THE  PLANTS, 

further.  We  saw  reason  to  believe  in  a  previous 
chapter  that  pgfel^  ^gre^ori^inally  sepals,  flat- 
tened and  brightly  coloured, ~an3 told  on  Tor  the 
special  attractive  function.  Just  in  the  same 
way  the  ray-florets  of  the  daisy,  the  sunflower, 
the  single  dahlia,  and  the  aster  are  florets  which 
have  been  flattened  and  partially  or  wholly 
sterilised  in  order  to  act  as  allurements  to 
insects.  The  ray-floret  acts  for  the  compound 
flower-head  as  the  petal  acts  for  the  individual 
blossom. 

In  many  other  families  of  plants  besides  the 
composites  we  get  foreshadowings,  so  to  speak, 
of  this  mode  of  procedure.  The  outer  flowers  of 
a  cluster,  be  it  head  or  umbel,  are  often  rendered 
larger  so  as  to  increase  the  effective  attractive- 
ness of  the  whole ;  and  sometimes  they  are 
sacrificed  to  the  inner  ones  by  being  made 
neuter  or  sterile,  that  is  to  say,  being  deprived 
of  stamens  and  pistil.  Thus  in  cow-parsnip, 
which  is  a  member  of  the  same  family  as  the 
carrot  and  the  hemlock,  the  outer  flowers  of  each 
umbel  are  much  larger  than  the  central  ones, 
while  in  the  wild  guelder-rose  the  central 
flowers  alone  are  fertile,  the  outer  ones  being 
converted  into  mere  expanded  white  corollas 
with  no  essential  floral  organs.  But  it  is  the 
composites  that  have  carried  this  process  of 
division  of  labour  furthest,  by  making  the  ray- 
florets  into  mere  petal-like  straps,  which  do  no 
work  themselves,  but  simply  serve  to  attract  the 
fertilising  insects  to  the  compound  flower-head. 

An  immense  number  of  these  composites  with 
flattened  ray-florets  grow  in  our  fields  or  are 


HOW   FLOWERS   CLUB   tfOGEtfHEB.  159 


cultivated  in  our  gardens.  In  the  simpler 
among  them,  such  as  the  sunflower,  the  corn- 
marigold,  the  ragwort,  and  the  golden-rod,  both 
ray-florets  and  central  florets  are  simply  yellow. 
But  in  others,  such  as  the  daisy,  the  ox-eye 
daisy,  the  aster,  and  the  camomile,  the  ray- 
florets  differ  in  colour  from  those  of  the  centre  ; 
the  latter  remain  yellow,  while  the  former 
become  white,  or  are  tinged  with  pink,  or  even 
flaunt  forth  in  scarlet,  crimson,  blue,  or  purple. 
Of  this  class  one  may  mention  as  familiar 
instances  the  dahlia,  the  zinnia,  the  Michaelmas 
daisies,  the  cinerarias,  and  the  pretty  coreopsis 
so  common  in  our  gardens.  Gardeners,  how- 
ever, are  not  content  to  let  us  admire  these 
flowers  as  nature  made  them.  They  generally 
"double"  them  —  that  is  to  say,  by  carefully 
selecting  certain  natural  varieties,  they  produce 
a  form  in  which  all  the  florets  have  at  last 
become  neutral  and  strap-  shaped.  This  is  well 
seen  in  the  garden  chrysanthemum,  where,  how- 
ever, if  you  open  the  very  centre  of  the  doubled 
flower-head,  you  will  generally  find  in  its  midst 
a  few  remaining  fertile  tubular  blossoms.  The 
same  process  is  also  well  seen  in  the  various 
stages  between  the  single  and  the  double  dahlia. 
Such  "double"  composites  can  set  little  or  no 
seed,  and  are  therefore  from  the  point  of  view  of 
the  plant  mere  abortions.  Nor  are  they  beautiful 
to  an  eye  accustomed  to  the  ground  plan  of  floral 
architecture.  Remember,  of  course,  that  what 
we  call  "  a  double  flower  "  in  a  rose,  a  butter- 
cup, or  any  other  simple  blossom  is  one  in 
which  the  stamens  have  been  converted  into 


160       THE  STOEY  OF  THE  PLANTS. 

supernumerary  and  useless  petals ;  while  in  a 
composite  it  is  a  flower-head  in  which  the  central 
florets  have  been  converted  into  barren  ray-florets. 
In  either  case,  however,  the  result  is  the  same — 
the  flowers  are  rendered  abortive  and  sterile. 

Nature's  way  is  quite  different.  Here  is  how 
she  manages  the  fertilisation  of  one  of  these  ray- 
bearing  composites — say  for  example  the  sun- 
flower, where  the  individual  florets  are  quite  big 
enough  to  enable  one  to  follow  the  process  with 
the  naked  eye.  The  large  yellow  rays  act  as 
advertisements ;  the  bee,  attracted  by  them, 
settles  on  the  outer  edgo.  and  fertilises  the 
flowers  from  without  inward.  To  meet  this 
habit  of  his,  the  florets  of  tire  sunflower  pass 
through  four  regular  stages.  They  opeji^P^S 
without  inward.  In  the  centre  are  unopened 
buds.  Next  come  open  flowers,  in  which  the 
stamens  are  shedding  their  pollen,  while  the 
stigmas  are  still  hidden  within  the  tube.  Third 
in  order,  we  get  florets  in  which  the  stamens 
have  withered,  while  the  stigmas  have  now 
ripened  Imcf  opened.  Last  of  all,  we  get,  next 
to  the  rays,  a  set  of  overblown  florets,  engaged 
in  maturing  their  fertilised  fruits.  The  bee  thus 
comes  first  to  the  florets  in  the  female  stage, 
which  he  fertilises  with  pollen  from  the  last 
uplant  he  visited ;  he  then  goes  on  to  florets  in 
the  male  stage,  where  he  collects  more  pollen 
for  tKeTnext  plant  to  which  he  chooses  to  devote 
his  attention.  The  florets  of  the  sunflower  are 
interesting  also  for  the  fact  that,  unlike  most 
composites,  they  still  retain  obvious  traces  of 
a  true 


BLOWERS    CLUB    TOGETHER.  161 

Hie  composites  which  produce  purple ^  or  blue 
ray-florets  to  attract  insects  are  in  some  ways  the 
highest  of  their  class.  Still,  there  is  another 
group  of  composites  which  has  proceeded  a 
little  further  in  ojae  direction  ;  and  that  is  the 
group  which  includes  the  dandelions.  In  these 
heads  all  the  florets  alike  have  become  strap- 
shaped  or  ray-like ;  but  they  differ  from  the 
double  composites  of  the  gardeners  in  this,  that 
each  floret  sUU^retains  its  stamens  and  pistil. 
The  composites^aoT"'"ffie  dandelion  group  are 
chiefly  weeds  like  the  hawkbit  and  the  sow- 
thistle.  A  few  are  cultivated  as  vegetables, 
such  as  lettuce,  salsify,  chicory,  and  endive ; 
fewer  still  are  prized  for  their  flowers  for 
ornamental  purposes,  such  as  the  orange  hawk- 
weed.  The  prevailing  colour  in  this  class  is 
yellow,  and  the  devices  for  insect-fertilisation 
are  not  nearly  so  high  as  in  the  ray-bearing 
group.  I  regard  them  as  to  a  great  extent  a 
retrograde  tribe  of  the  composite  family. 

In  this  chapter  I  have  dealt  chiefly  with  the 
co-operative  clubbing  together  of  insect-fertilised 
flowers,  for  purposes  of  mutual  convenience  ;  but 
you  must  not  forget  that  similar  clubs  exist  also 
among  the  wind-fertilised  blossoms  in  quite  equal 
profusion.  Such  are  the  catkins  of  forest  trees, 
the  panicles  of  grasses,  the  spikes  of  sedges,  and 
the  heads  of  the  black-cap  rush  and  many  other 
water-plants.  Some  of  these,  such  as  the  bur- 
reed,  we  have  already  considered. 

Lastly,  I  ought  to  add  that  where  the  flowers 
themselves  are  inconspicuous,  attention  is  often 
called  to  them  by  a  bright-coloured  leaf  or  group 
11 


162       THE  STORY  OF  THE  PLANTS. 

of  leaves  in  their  immediate  neighbourhood.  We 
saw  an  instance  of  this  in  the  great  white  spathe 
or  folding  leaf  which  encloses  the  male  and 
female  flowers  of  the  "  calla  lily."  In  the 
greenhouse  poinsettia  the  individual  flowers  are 
tiny  and  unnoticeable ;  but  they  are  rich  in 
honey,  and  round  them  has  been  developed  a 
great  bunch  of  brilliant  scarlet  leaves  which 
renders  them  among  the  most  decorative 
objects  in  nature.  A  lavender  that  grows  in 
Southern  Europe  has  dusky  brown  flowers ; 
but  the  bunch  is  crowned  by  a  number  of 
mauve  or  lilac  leaves,  hung  out  like  flags  to 
attract  the  insects.  A  scarlet  salvia  much 
grown  in  windows  similarly  supplements  its 
rather  handsome  flowers  by  much  handsomer 
calyxes  and  bracts  which  make  it  a  perfect  blaze 
of  splendid  colour.  It  doesn't  matter  to  the 
plant  how  it  produces  its  effect;  all  it  cares 
for  is  that  by  hook  or  by  crook  it  should 
attract  its  insects  and  get  itself  fertilised. 


CHAPTEK  XI. 

WHAT  PLANTS  DO  FOB  THEIR  YOUNG. 

AFTER  the  flower  is  fertilised  it  has  to  set  its 
seed.  And  after  the  seed  is  set  the  plant  has  to 
sow  and  disperse  it. 

Now,  the  fruit  and  seed  form  the  most  difficult 
part  of  technical  botany,  and  I  will  not  apologise 
for  treating  them  here  a  little  cavalierly.  I  will 
tell  you  no  more  about  them  than  it  is  actually 


WHAt   PLANTS   DO    FOE   tfHElft   YOUNG.        163 

necessary  you  should  know,  leaving  you  to 
pursue  the  subject  if  you  will  in  more  formal 
treatises. 

The  pistil,  after  it  has  been  fertilised  and 
arrived  at  maturity,  is  called  the  fruit.  In 
flowers  like  the  buttercup,  where  there  are 
many  carpels,  the  fruit  consists  of  distinct 
parts,  each  one-seeded  little  nuts  in  the  meadow 
buttercup,  but  many-seeded  pods  in  the  marsh- 
marigold  and  the  larkspur.  Where  the  carpels 
have  combined  into  a  single  ovary,  we  get  a 
many-chambered  fruit,  as  in  the  poppy,  which 
consists,  when  cut  across,  of  ten  seed-bearing 
chambers.  Most  fruits  are  dry  capsules  or  pods, 
either  single,  as  in  the  pea,  the  bean,  the  vetch, 
and  the  laburnum  ;  or  double,  as  in  the  wallflower 
and  shepherd* s-purse  ;  or  many-chambered,  as 
in  the  lily,  the  wild  hyacinth,  the  poppy,  the 
campion.  As  a  rule  the  fruit  consists  of  as 
many  carpels  or  as  many  chambers  as  the 
unfertilised  ovary. 

Fruits  are  often  dispersed  entire,  and  this  is 
especially  true  when  they  contain  only  one  or 
two  seeds.  In  such  instances  they  sometimes 
fall  on  the  ground  direct,  as  is  the  case  with 
most  nuts ;  or  else  they  have  wings  or  para- 
chutes which  enable  the  wind  to  seize  them, 
and  carry  them  to  a  distance,  where  they  can 
alight  on  unexhausted  soil,  far  away  from  the 
roots  of  the  mother  plant.  Such  fruits  are 
common  among  forest  trees.  The  maples,  for 
example,  have  a  double  fruit,  often  called  a 
key,  which  the  wind  whirls  away  as  soon  as  the 
seeds  are  ready  for  dispersion  (Figs.  37,  38,  39, 


164 


THE   STOBY  OF  THE   PLANTS. 


40,  41).     In  the  lime,  the  common  stalk  of  the 
flowers  is  winged  by  a  thin  leaf ;  and  when  the 


little  nuts  are  ripe  the  wind  detaches  them  and 
carries  them  away  by  means  of  this  joint  para- 
chute. In  the  birch,  elm,  and  ash  the  fruit  is 


WHAT  PLANTS  DO  FOE  THEIE  YOUNG.   165 

a  one-seeded  nut,  with  its  edge  produced  into 
a  leathery  or  papery  wing,  which  serves  to 
float  it. 

But  more  often  the  fruit  at  maturity  opens 
and  scatters  its  seeds,  as  we  see  in  the  pea,  the 
wild  hyacinth,  and  the  iris.  Sometimes  the 
seeds  so  released  merely  drop  upon  the  ground, 
but  most  often  some  device  exists  for  scattering 
them  to  a  distance,  so  as  to  obtain  the  advantage 
of  unexhausted  soil  for  the  young  seedling.  Thus 
most  capsules  open  at  the  top,  so  that  the  seeds 
can  only  drop  out  when  the  wind  is  high  enough 
to  carry  them  to  some  distance.  In  the  poppy- 
head  the  capsule  opens  by  pores  at  the  side, 
and,  if  you  shake  one  as  it  grows,  you  will  find 
it  takes  a  considerable  shaking  to  dislodge  the 
seeds  from  the  walls  of  their  chamber.  Thus 
only  in  high  winds  are  the  poppy  seeds  dis- 
persed. In  the  mouse-ear  chickweed  the  cap- 
sule is  directed  slightly  upward  at  the  end  for 
a  similar  purpose.  Sometimes,  again,  the  valves 
of  the  fruit  open  elastically  and  shoot  out  the 
seeds ;  this  device  is  familiarly  known  in  the 
garden  balsam,  and  it  occurs  also  in  the  little 
English  wallcress.  The  sandbox-tree  of  the 
West  Indies  has  a  large  round  woody  capsule, 
which  bursts  with  a  report  like  a  pistol,  and 
scatters  its  seeds  with  such  violence  as  to  inflict 
a  severe  wound  upon  anybody  who  happens  to 
be  struck  by  them. 

Where  seeds  are  numerous,  they  are  oftenest 
dispersed  in  some  such  manner,  by  the  capsule 
opening  naturally  and  scattering  its  contents ; 
but  where  they  are  few  in  number,  it  more, 


166 


THE    STOEY   OF   THE   PLANTS. 


frequently  happens  that  the  fruit  does  not  open, 
as  in  the  oak  or  the  elm  ;  and  when  there  is 
only  one  seed,  the  fruit  and  seed  become  almost 


indistinguishable,  and  are  popularly  regarded  as 
a  seed  only.  For  example,  in  the  pea,  we  dis- 
tinguish at  once  between  the  pod,  which  is  a 
fruit  containing  many  seeds,  and  the  pea  which 


WHAT  PLANTS  DO  FOE  THEIR  YOUNG.    167 

is  one  such  seed  among  the  many ;  but  in  wheat 
or  oats  the  fruit  is  small  and  one-seeded,  and  its 
covering  is  so  closely  united  with  the  seed  as  to 
be  practically  inseparable.  Fruits  like  these  do 
not  open,  and  are  dispersed  whole.  The  fruits 
of  most  composites  are  crowned  by  the  feather- 
like  hairs  which  represent  the  calyx,  and  float 
on  the  breeze  as  thistledown  or  dandelion-clocks 
(Figs.  42,  43,  44,  45).  John-go-to-bed-at-noon, 
an  English  composite  of  the  dandelion  type,  has 
a  very  remarkable  and  highly-developed  para- 
chute of  this  description.  In  the  anemones  and 
clematis  the  fruit  consists  of  several  distinct 
one-seeded  carpels,  each  furnished  with  a  long 
feathery  awn  for  the  purpose  of  floating;  our 
common  English  clematis  or  traveller's  joy, 
when  in  the  fruiting  condition,  is  known  on  this 
account  as  "old  man's  beard."  Floating  fruits 
like  these,  or  those  of  many  sedges  and  grasses, 
will  often  be  carried  by  the  wind  for  miles 
together.  A  well-known  example  of  this  type 
is  the  sedge  commonly  though  wrongly  described 
as  cotton-grass. 

In  other  instances  it  is  the  seed,  not  the  fruit, 
that  is  winged  or  feathered.  The  pod  of  the 
willow  opens  at  maturity,  and  allows  a  large 
number  of  cottony  seeds  to  escape  upon  the 
breeze.  The  same  thing  happens  in  the  beau- 
tiful rose-bay  and  the  other  willow-herbs. 
Cotton  is  composed  of  the  similar  floating  hairs 
attached  to  the  seeds  of  a  sub-tropical  mallow- 
like  tree. 

You  will  have  observed,  however,  that  not  one 


168       THE  STORY  OF  THE  PLANTS. 

of  the  fruits  which  I  have  hitherto  mentioned 
is  a  fruit  at  all  in  the  common  or  popular  accep- 
tation of  the  word.  They  are  only  at  best  what 
most  people  call  pods  or  capsules.  A  true  fruit, 
as  most  people  think  of  it,  is  coloured,  juicy, 
pulpy,  sweet,  and  edible.  How  did  such  fruits 
come  into  existence,  and  what  is  the  use  of 
them? 

Well,  just  as  certain  plants  desire  to  attract 
insects  to  fertilise  their  flowers,  so  do  other 
plants  desire  to  attract  birds  and  beasts  to 
disseminate  their  fruits  for  them.  If  any  fruit 
happened  to  possess  a  coloured  and  juicy  outer 
coat,  or  to  show  any  tendency  towards  the 
production  of  such  a  coat,  it  would  sooner  or 
later  be  eaten  by  animals.  If  the  animal 
digested  the  actual  seed,  however,  so  much 
the  worse  for  the  plant,  and  we  shall  see  by 
and  by  that  most  plants  take  great  care  to 
prevent  their  true  seeds  being  eaten  and  assimi- 
latecl  by  animals.  But  if  the  seed  was  very 
small  and  tough,  or  had  a  stony  covering,  it 
would  either  be  passed  through  the  animal's  body 
undigested,  or  else  thrown  away  by  him  when 
he  had  finished  eating  the  pulpy  exterior.  So, 
many  plants  have  acquired  fruits  of  this  de- 
scription— edible  fruits,  intended  for  the  attrac- 
tion of  birds  and  animals.  As  a  rule  the  animals 
disperse  the  seeds  in  the  well-manured  soil  near 
their  own  nests  or  lairs,  so  that  the  young  plants 
produced  from  such  fruits  start  in  life  under 
exceptional  advantages. 

Fruits  that  seek  to  attract  animals  use  much 
the  sarne  baits  to  allure  them  in  the  way  of 


WHAT  PLANTS  DO  FOR  THEIR  YOUNG.    1G9 

colour  and  sweet  taste  as  do  the  flowers  that 
seek  to  attract  insects.  But  just  as  almost  any 
part  of  the  flower  may  be  brightly  coloured,  so 
almost  any  part  of  the  fruit  may  be  sweet  and 
pulpy.  Thus  we  get  an  astonishing  and  rather 
embarrassing  variety  of  special  devices  in  this 
matter. 

A  few  instances  must  suffice  us.  In  the 
raspberry  and  blackberry  the  fruit  consists  of 
separate  carpels,  in  each  of  which  the  outer 
coat  becomes  soft  and  sweet,  while  the  actual 
seed  is  hard  and  nut-like.  In  the  one  case  the 
fruit  is  red,  in  the  other  black,  but  very  con- 
spicuous among  the  green  leaves  in  autumn. 
These  berries  are  eaten  by  birds,  and  their  seeds 
are  dispersed  in  copse  or  hedgerow.  But  in  the 
strawberry,  which  is  a  near  relation  of  both, 
with  a  very  similar  flower,  the  actual  carpels 
remain  to  the  end  quite  small  and  seed -like ; 
they  are  the  tiny  black  objects  scattered  about 
in  pits  like  miniature  nuts  over  the  surface  of 
the  ripe  berry.  Here  it  is  the  common  recep- 
tacle of  the  fruit  that  swells'outf  andT  reddens, 
the  part  answering  to  the  central  piece  which 
comes  out  whole  in  the  middle  of  the  raspberry ; 
so  that  what  we  eat  in  the  one  fruit  is  the  very  \ 
same  part  as  what  we  throw  away  in  the  other.  \ 
In  the  plum,  the  cherry,  and  the  peach,  on  the 
other  hand,  there  is  but  one  carpel,  and  its  outer 
covering  grows  soft,  sweet,  and  brightly  coloured; 
while  the  actual  seed,  though  soft,  is  contained 
in  a  hard  and  stony  jacket,  an  inner  layer  of  the 
fruit  coat.  Here  the  true  seed  is  what  we  call 
the  kernel,  but  it  is  amply  protected  by  its  bone- 


170       THE  STORY  OF  THE  PLANTS. 

like  coverlet.  In  the  apple  and  pear  the  ovary 
is  inferior ;  the  fruit  is  thus  crowned  by  the 
remains  of  the  calyx ;  if  you  cut  it  across  you 
will  find  it  consists  of  a  fleshy  part,  which  is  the 
swollen  stem,  enclosing  the  true  fruit  or  core, 
with  a  number  of  seeds  which  we  call  the  pips. 
All  these  fruits  belong  to  the  family  of  the  roses ; 
they  serve  to  show  the  immense  variety  ol  plan 
and  structure  which  occurs  even  in  closely  re- 
lated species.  Other  succulent  fruits  of  the 
same  family  are  the  rose-hip,  the  haw,  the 
medlar,  and  the  nectarine. 

Among  familiar  woodland  fruits  dispersed  by 
birds  I  may  mention  the  elderberry,  the  dog- 
wood, the  honeysuckle,  the  whortleberry,  the 
holly,  the  cuckoo-pint,  the  barberry,  and  the 
spindle-tree.  The  white  berries  of  the  mistletoe, 
which  is  a  parasitic  plant,  are  eaten  by  the 
missel-thrush,  a  bird  who  has  a  special  affection 
for  this  particular  food.  But  they  are  very 
sticky,  and  the  seeds  therefore  adhere  to  the 
bird's  beak  and  feet.  To  get  rid  of  them,  he 
rubs  them  off  on  the  fork  of  a  poplar  branch,  or 
in  the  bark  of  an  apple-tree,  which  are  the  exact 
places  where  the  mistletoe  most  desires  to  place 

I  itself.   Many  such  close  correspondences  between 

1  bird  and  fruit  exist  in  nature. 

Our  northern  berries  are  chiefly  designed  to 
be  eaten  by  small  birds  like  robins  and  haw- 
finches. But  in  southern  climates  larger  fruits 
exist,  adapted  to  the  tastes  of  larger  animals 
such  as  parrots,  toucans,  hornbills,  fruit-bats, 
and  monkeys.  Our  own  small  kinds  can  gene- 
rally be  eaten  whole?  like  the  currant  and  the 


WHAT  PLANTS  DO  FOB  THEIR  YOUNG.    171 

strawberry  ;  but  these  large  southern  fruits  have 
often  a  bitter  or  unpleasant  or  very  thick  rind, 
which  the  birds  or  monkeys,  for  whose  use  they 
are  intended,  know  how  to  strip  off  them. 
Cases  in  point  are  the  orange,  the  lemon,  the 
shaddock,  the  banana,  the  pine-apple,  the 
mango,  the  custard-apple,  and  the  breadfruit. 
The  melon,  cucumber,  pumpkin,  gourd,  vegetable 
marrow,  and  water-melon  are  other  southern 


FIG.    4t>. 


FIG.    47. 


FIG.    48. 


ADHESIVE  FRUITS.     Fig.  46,  of  houndstoDgue.     Fig.  47,  of 
cleavers.    Fig.  48,  of  herb-bennet. 

forms  cultivated  in  the  north  for  the  sake  of 
their  fruits.  In  the  pomegranate  the  fruit  itself 
is  a  dry  capsule,  but  the  seeds  are  each  enclosed 
in  a  separate  juicy  coat.  The  grape  is  a  fruit  too 
well  known  to  require  detailed  description. 

As  flowers  sometimes  club  together,  so  also  do 
fruits.  In  the  mulberry  the  apparent  berry  is 
really  made  up  of  the  distinct  carpels  of  several 
separate  flowers,  which  grow  together  as  they 


172       THE  STORY  OP  THE  PLANTS. 

ripen ;  while  the  fig  is  a  hollow  stalk,  in  which 
numerous  tiny  fruits,  commonly  called  seeds,  are 
closely  embedded. 

In  all  these  cases  animals  act  as  willing  agents 
in  the  dispersal  of  fruits  or  seeds.  But  some- 
times the  plant  compels  them  to  carry  its  seeds 
against  their  will.  Thus  the  fruits  of  the  hounds- 
tongue  (Fig.  46)  consist  of  four  small  nuts,  covered 
with  hook-like  prickles,  which  cling  to  the  coats 
of  sheep  or  cattle.  The  beasts  rub  these  annoying 
burdens  off  against  bushes  or  hedges,  and  so 
disseminate  the  seeds  in  suitable  places  for  ger- 
mination. The  double  fruit  of  cleavers  (Fig.  47) 
is  also  supplied  with  similar  prickles,  while  that 
of  herb-bennet  (Fig.  48)  has  a  long  curved  awn 
whicji  makes  it  catch  at  once  on  any  passing 
animal. 

There  are  a  large  number  of  fruits,  however, 
with  richly  stored  seeds,  which  desire  rather  to 
escape  the  notice  of  animals,  some  of  whom,  like 
squirrels  and  dormice,  try  to  make  their  living 
out  of  them.  These  we  call  nuts.  Their  tactics 
are  the  exact  opposite  of  those  pursued  by  the 
edible  fruits.  For  the  edible  fruits  strive  to 
attract  animals  to  disperse  them ;  the  nuts,  on 
the  contrary,  having  the  actual  seed  richly  stored 
with  oils  and  starches,  desire  to  protect  it  from 
being  eaten  and  destroyed.  Hence  they  are 
generally  green  when  on  the  tree,  so  as  to 
escape  notice,  and  brown  when  lying  on  the 
ground  beneath  it.  Cases  of  these  protectively- 
arranged  fruits,  with  hard  shells  and  often  with 
nauseous  external  coverings  (some  of  which  are 


WHA1?   PLANTS   1>O   FOB  THEIR  tOUNG.        173 

not  regarded  as  nuts  in  the  strict  botanical 
sense),  are  the  walnut,  the  hazel-nut,  the  coco- 
nut, the  chestnut,  the  acorn,  the  lime-nut,  the 
almond,  and  the  hickory-nut.  In  the  Brazil  nut 
the  seeds  (which  are  what  we  commonly  call  the 
nuts)  are  enclosed  in  a  solid  shell  like  that  of  a 
coco-nut,  and  are  themselves  also  hard  and  nut- 
like.  In  the  chestnut  the  fruit  is  a  prickly 
capsule,  inside  which  lie  the  seeds,  which  we 
know  as  chestnuts. 

But  why  have  some  plants  so  many  seeds  and 
some  so  few?  Well,  the  simpler  and  earlier 
types  produce  a  very  large  number  of  ill-pro- 
vided seeds,  which  they  turn  loose  upon  the 
world  to  shift  for  themselves  almost  from  the 
outset.  Many  of  them  perish,  but  a  few  survive. 
On  the  other  hand,  the  more  advanced  plants, 
as  a  rule,  produce  only  a  small  number  of  seeds, 
but  each  of  these  is  well  provided  with  starches 
and  oils  for  the  growth  of  the  young  plant ;  and 
as  most  such  survive,  any  tendency  in  the  direc- 
tion of  laying  by  food- stuffs  would  of  course  be 
favoured  by  natural  selection.  Just  so  among 
animals,  a  codfish  produces  nearly  a  million 
eggs,  of  which  only  two  or  three  on  an  average 
survive  to  maturity ;  while  a  bird  produces  half 
a  dozen  large  and  well- stored  eggs,  and  a  cow  or 
a  horse  rarely  brings  forth  more  than  one  calf  or 
foal  at  a  birth.  Decrease  in  the  number  of  seeds/ 
is  a  fair  jrou^h  test,  of  relative  progress. 

In  nuts,  you  can  see  at  once,  the  seeds  are 
very  richly  stored,  and  the  young  plant  starts 
in  life,  able  to  draw  for  a  time  on  these  ready- 


174  THE  sfomr  OF 

made  food-stuffs,  until  its  green  leaves  are  in  a 
position  to  lay  by  starches  "and  protoplasm  in 
plenty  for  it.  It  draws  by  degrees  upon  the 
/accumulated  materials.  Such  plants  are  like 
'  capitalists  who  can  start  their  sons  well  in  life 
with  a  good  beginning.  On  the  other  hand,  the 
poppy  has  to  set  out  on  its  career  with  a  very 
poor  equipment ;  it  must  begin  picking  up  car- 
bonic acid  for  itself  almost  from  the  outset. 
Such  plants  are  like  street  arabs,  compelled 
to  shift  as  best  they  can  from  their  earliest 
days.  A  coco-nut  starts  so  well  that  the  young 
palm  can  grow  to  a  considerable  size  without 
working  for  itself ;  so  to  a  less  degree  do  wal- 
nuts, hazels,  and  oak-trees.  Among  other  sets 
of  plants  there  are  two  great  groups  which  have 
especially  learned  to  lay  by  food  for  their  seed- 
lings— the  peaflower  family  and  the  grasses. 
In  both  these  cases  the  young  plants  start  in  life 
with  exceptional  advantages.  But  what  will 
feed  a  young  plant  will  also  feed  an  animal. 
Hence  men  live  largely  in  different  countries 
off  such  richly-stored  seeds — among  nuts,  the 
coco-nut,  the  chestnut,  and  the  walnut ;  among 
peaflower  seeds,  the  pea,  the  bean,  the  vetch, 
the  lentil;  among  grasses,  wheat,  rice,  barley, 
Indian  corn,  rye,  millet. 

Eecollect,  however,  that  in  all  these  cases  the 
plant  does  not  desire  the  seed  to  be  eaten.  It 
stored  the  tissues  richly  for  its  own  sake  and  its 
offspring's  alone,  and  we  come  and  rob  it.  So, 
too,  with  the  edible  roots  or  tubers,  such  as 
potatoes,  yams,  turnips,  beet-root,  and  so  forth ; 
the  plant  meant  to  use  them  for  its  own  future 


WHAT  PLANTS  DO  FOR  THEIR  YOUNG.      175 

growth ;  man  appropriates  them  and  disappoints 
its  natural  expectations.  It  is  quite  different 
with  the  succulent  fruits,  like  the  date  and  the 
plantain,  which  form  in  many  countries  the 
staple  food  of  great  populations ;  nature  meant 
those  to  be  eaten  by  animals,  and  offered  the 
pulp  in  return  for  the  benefit  of  dispersion. 

Finally,  when  the  seed  is  put  into  the  ground 
and  exposed  to  warmth  and  moisture,  it  begins 
to  germinate.  This  it  does  by  sending  up  a 
small  growing  shoot  towards  the  light,  which 
soon  develops  green  leaves  ;  as  well  as  by 
sending  down  a  root  towards  the  earth,  which 
soon  begins  to  suck  up  water,  together  with  the 
dissolved  nitrogenous  matter.  That  is  the  be- 
ginning of  a  fresh  plant-colony,  which  thus  owes 
its  existence  to  two  separate  individuals,  a  father 
and  a  mother.  The  seed  consists  of  two_  first 
seed-leaves  in  the  fivefold  plants,  as  you  can  see 
very  well  in  a  sprouHng  bean,  and  of  one  such 
seed-leaf  in  the  threefold  division,  as  you  can 
see  very  well  in  a  sprouting  grain  of  wheat,  or, 
still  better,  a  lily  seed.  These  earliest  leaves 
are  technically  known  as  seed-leaves  or  cotyle- 
dons, and  that  is  why  the  fivefold  plants  are 
known  to  botanists  by  the  awkward  name  of 
dicotyledons,  while  the  threefold  are  called 
monocotyledons.  These  names  mean  merely 
plants  with  two  or  with  one  seed-leaf. 


CHAPTER    XII. 

THE    STEM    AND    BRANCHES. 

You  may  have  observed  that  so  far  I  have  told 
you  a  good  deal  about  leaves  and  roots,  flowers 
and  seeds,  but  little  or  nothing  about  the  nature 
of  the  stems  and  branches  that  bear  them.  I 
have  done  this  on  purpose;  for  my  object  has 
been  to  give  you  as  much  information  at  a  time 
as  you  could  then  and  there  understand,  build- 
ing up  by  degrees  your  conception  of  plant 
economy.  Now,  leaves  and  flowers  are,  so  to 
speak,  the  units  of  the  plant-colony,  while  stem 
and  branches  are  the  community  as  a  whole  and 
the  mode  of  its  organisation.  You  must  know 
something  about  the  component  parts  before 
you  can  get  to  understand  the  whole  built  up 
of  them  ;  you  must  have  seen  the  individual 
citizens  themselves  before  you  can  comprehend 
the  city  or  nation  composed  by  their  union. 

The  stem,  then,  is  the  part  of  the  plant-colony 
which  does  not  consist  of  individual  leaves, 
either  digestive  or  floral,  but  which  binds  them 
all  together,  raises  them  visibly  to  the  air,  and 
supplies  them  with  water,  nitrogenous  matter, 
and  the  results  of  previous  assimilation  else- 
where. The  stem  and  branches  are  common 
property,  as  it  were ;  they  belong  to  the  com- 
munity :  they  represent  the  scaffolding,  the 
framework,  the  canals,  the  roads,  the  streets, 
the  sewers,  of  the  compound  plant-colony. 

How  did  stems  begin  to  exist  at  all  ?     The 

176 


SFEM   AND 


17? 


taost  probable  answer  to  that  question  we  ;owe, 
not  to  any  professional  botanist,  but  to  our 
great  philosopher,  Mr-.  Herbert  Spencer. 

The  simplest  and  earliest  plants,  we  saw-, 
were  mere  small  floating  cells,  endowed  with 
active  chlorophyll.  Next  in  the  upward  order 
of^evolution  came  rows  of  such  cells,  arranged 
in  long  lines,  like  hairs  or  threads,  or  like 
pearls  in  a  necklace, 
as  in  the  green  ooze 
of  ponds  and  lake- 
lets. Above  these 
simple  plants,  again , 
come  flat  expanded 
collections  of  cells, 
as  in  the  fronds  of 
seaweeds.  Now,  all 
these  kinds  of  plant 
are  stemless.  But 
suppose  in  such  a 

plant    as    the    last,      FIG.  49. — FIRST  STEPS  IN  THE 
one    frond    or    leaf         EVOLUTION  OF  THE  STEM. 
took  to  growing  out 

of  the  middle  of  another,  as  it  actually  does 
in  many  instances,  we  should  get  the  beginning 
of  a  compound  plant,  many-leaved,  and  with  a 
sort  of  early  or  nascent  stem,  formed  by  the 
part  that  was  common  to  many  of  the  leaves, 
like  a  midrib.  The  accompanying  diagram 
(Fig.  49)  will  make  this  clearer  than  any  amount 
of  description  could  possibly  make  it.  Starting 
from  such  a  point,  certain  plants  would  soon 
find  they  were  thus  enabled  to  overtop  others, 
and  to  obtain  freer  access  to  lighr"ancf  carbonic 
12 


178        THE  STORY  OF  THE  PLANTS. 

acid.  Gradually,  natural  selection  would  ensure 
that  the  common  central  part  of  the  growing 
plant,  the  developing  stem,  should  become 
harder  and  more  resisting  than  the  rest,  so  as 
to  stand  up  against  the  wind  and  other  opposing 
forces.  At  last  there  would  thus  arise  a  clearly- 
marked  trunk,  simple  at  first,  but  later  on 
branching,  which  would  lift  the  leaves  and 
flowers  to  a  considerable  height,  and  hang  them 
out  in  such  a  way  as  to  caTjcrTTihe  sunlight  and 
air  to  the  best  advantage,  or  to  attract  the 
fertilising  insects  or  court  the  wind  under  the 
fairest  conditions.  I  leave  you  to  think  out  for 
yourself  the  various  stages  of  the  process  by 
which  natural  selection  must  in  the  end  secure 
these  desirable  objects. 

In  order  to  understand  the  nature  of  the  stem, 
in  its  fully  developed  form,  however,  we  must 
remember  that  it  has  three  main  functions. 
The  first  is,  to  rajise  the  foliage,  with  the  flowers 
and  fruits  as  well,  visibly  above  the  surface  of 
the  ground  on  which  they  grow,  so  that  the 
leaves  may  gain  the  freest  possible  access  to 
rays  of  sunlight  and  to  carbonic  acid,  while  the 
flowers  and  fruit  may  receive  the  attentions  of 
insects  and  birds,  or  other  fertilising  and  dis- 
tributing agents.  The  second  is,  to  conduct 
from  the  root  to  the  foliage  and  other  growing 
parts  wrhat  is  commonly  called  the  raw  sap — 
that  is  to  say,  the  body  of  water  absorbed  by 
the  rootlets,  together  with  the  nitrogenous 
matter  and  food-salts  dissolved  in  it,  all  of 
which  are  needed  for  the  ultimate  manufacture 


THE    STEM    AND    BRANCHES.  179 

of  protoplasm  and  chlorophyll.  The  third  is,  to 
carry  away  and  distribute  the  various  matured 
products  of  plant  life,  such  as  starches,  sugars, 
oils,  and  protoplasm,  from  the  places  in  which 
they  are  produced  (such  as  the  leaves)  to  tho 
places  where  they  are  needed  for  building  up 
the  various  parts  of  the  compound  organism 
(such  as  the  flowers  and  fruit  or  the  growing 
shoots),  as  well  as  to  the  places  where  such 
materials  are  to  be  stored  up  for  safety  or  for 
future  use  (as,  for  example,  the  tubers  and  roots, 
or  the  buds,  bulbs,  and  other  dormant  organs). 
Each  of  these  three  essential  functions  we  must 
now  proceed  to  consider  separately. 

In  order  to  raise  the  leaves  and  branches 
visibly  above  the  ground  into  the  air  above  it, 
the  stem  is  made  much  stronger  and  stouter 
than  the  ordinary  leaf -tissue.  If  the  plant  does 
not  rise  very  high  above  the  ground,  indeed,  as 
in  the  case  of  small  herbs,  and  especially  of 
annuals,  its  stem  need  not  be  very  hard  or  stiff, 
and  is  often  in  point  of  fact  quite  green  and 
succulent.  But  just  in  proportion  as  plants 
grow  tall  and  spreading,  carry  masses  of  foliage, 
and  are  exposed  to  heavy  winds,  do  they  need 
to  form  a  stout  and  woody  stem,  which  shall 
support  the  constant  weight  of  the  leaves,  or 
even  bear  up  under  the  load  of  snow  which  may 
cover  the  boughs  in  wintry  weather.  Thus,  a 
tapering  tree  like  the  Scotch  fir  requires  a  com- 
paratively smaller  stem  than  an  oak,  because  its 
branches  do  not  spread  far  and  wide,  while  its 
single  leaves  are  thin  and  needle-like  ;  whereas 


180  THE   'STORY   OF   THE   PLANTS. 

the  oak,  with  its  massive  boughs  extending  fax* 
and  wide  on  every  side,  and  covered  with  a 
weight  of  large  and  expanded  absorbent  leaves, 
requires  a  peculiarly  thick  and  buttressed  stem 
to  support  its  burden.  Both  in  girth  and  in 
texture  it  must  differ  widely  from  the  loose  and 
swaying  pine-tree.  Every  stem  is  thus  a  piece 
of  ingenious  engineering  architecture,  adapted 
on  the  average  to  the  exact  weight  it  will  have 
to  bear,  and  the  exact  strains  of  wind  and 
weather  to  which  on  the  average  it  may  count 
upon  being  exposed  in  the  course  of  its  life- 
history.  We  see  the  result  of  occasional  failure 
of  adaptation  in  this  respect  after  every  great 
storm,  when  the  corn  in  the  fields  is  beaten 
down  by  hail,  or  the  fir-trees  in  the  forest  are- 
snapped  off  short  like  straw  by  the  force  of  the 
tempest.  But  the  survivors  in  the  long  run  are 
those  which  have  succeeded  best  in  resisting 
even  such  unusual  stresses ;  and  it  is  they  that 
become  the  parents  of  after  generations,  which 
of  course  inherit  their  powers  of  resistance. 

Most  stems,  at  least  of  perennial  plants,  and 
all  those  of  bushes,  shrubs,  and  forest  trees,  are 
strengthened  for  the  purpose  of  resisting  such 
strains  by  means  of  a  material  which  we  call 
wood.  And  what  is  wood  ?  Well,  it  is  an 
extremely  hard  and  close-grained  tissue,  manu- 
factured by  the  plant  out  of  its  ordinary  cells 
by  a  deposit  on  their  walls  of  thickening  matter. 
This  process  of  thickening  goes  on  in  each  cell 
until  the  hollow  of  the  centre  is  almost  entirely 
filled  up  by  the  thickening  material,  leaving  only 
a  small  vacant  space  in  the  very  middle.  The 


THE    STEM    AND    BKANCHES.  181 

thickening  matter,  which  consists  for  the  most 
part  of  carbon  and  hydrogen,  is  built  up  there 
by  the  protoplasm  of  the  cell  itself  :  but  as  soon 
as  the  process  is  quite  complete,  the  protoplasm 
emigrates  from  the  cell  entirely,  and  goes  to 
some  other  place  where  it  is  more  urgently 
needed.  Thus  wood  is  made  up  of  dead  cells, 
whose  walls  are  immensely  thickened,  but  whose 
living  contents  have  migrated  elsewhere. 

In  large  perennial  stems,  like  those  of  oaks 
and  elms,  a  fresh  ring  of  wood  is  added  each 
year  outside  the  ring  of  the  last  growing  season. 
This  new  ring  of  wood  is  interposed  between  the 
bark  (of  which  I  shall  speak  presently)  and  the 
older  wood  of  the  core  or  heart,  which  was 
similarly  laid  down  when  the  tree  was  younger. 
In  this  way,  the  number  of  rings,  one  inside 
another,  enables  us  roughly  to  estimate  the  age 
of  a  tree  when  we  cut  it  down ;  though,  strictly 
speaking,  we  can  only  tell  how  many  times 
growth  in  its  trunk  was  renewed  or  retarded. 
Still,  as  a  fair  general  test,  the  number  of  rings 
in  a  trunk  give  us  an  approximate  idea  of  the 
age  of  the  individual  tree  that  produced  it. 

The  principle  is  only  true,  however,  of  the 
great  group  of  dicotyledonous  trees,  such  as 
beeches  or  ashes,  as  well  as  of  the  pines  and 
other  conifers.  In  monocotyledonous  trees,  like 
the  palms  and  bamboos,  the  stem  does  not 
increase  in  quite  the  same  wray  from  within 
outward,  and  there  are  therefore  no  rings  of 
annual  growth  to  judge  by.  Palms  rise  from 
the  ground  as  big  or  nearly  as  big  at  the  begin- 
ning as  they  will  ever  be  in  the  end ;  and  though 


182       THE  STOKY  OF  THE  PLANTS. 

each  year  they  rise  higher  and  higher  into  the 
air,  and  produce  a  fresh  bunch  of  leaves  at  their 
summit,  they  seldom  branch,  and  they  never 
produce  large  buttressed  sterns  like  the  oak  or 
the  chestnut. 

The  second  main  function  of  the  stem  is  to 
convey  the  raw  sap  absorbed  by  the  roots  to  the 
leaves  and  branches,  and  especially  to  the 
growing  points.  This  is  such  a  very  important 
element  in  plant  life  that  we  must  now  consider 
it  in  some  little  detail. 

If  you  look  for  a  moment  at  a  great  spreading 
oak-tree,  with  its  top  rising  forty  or  fifty  feet 
above  the  level  of  the  ground,  and  its  roots 
spreading  as  far  and  as  deep  beneath  the  earth, 
you  will  see  at  once  how  serious  and  difficult  a 
mechanical  problem  it  is  for  the  plant  to  raise 
up  water  from  so  great  a  depth  to  so  great  a 
height  without  the  aid  of  pump  or  siphon.  For 
the  plant  can  no  more  work^miragles  than  you 
or  I  can.  Yet  every  leaf  must  be  constantly 
supplied  with  water,  that  prime  necessary  of 
life,  or  it  will  wither  and  die ;  and  every  growing 
part  must  obtain  it  in  abundance,  in  order  to 
give  that  plasticity  and  freedom  which  are 
needful  for  the  earlier  constructive  processes. 
^Protoplasm  itself  can  effect  nothing  without  the 
assistance  of  water  as  a  solvent  for  all  materials 
<jit  employs  in  its  operations. 

How  does  the  plant  get  over  these  difficulties  ? 
Well,  the  stem  is  well  provided  with  a  whole 
system  of  upward  distributing  vessels  in  which 
water  may  be  conveyed  to  the  various  parts, 


THE    STEM    AND    BBANCHES.  183 

just  as  it  is  conveyed  in  towns  through  the  pipes 
and  taps  wherever  it  is  needed.  But  what  is 
the  motive  power  for  this  mechanical  work  ? 
How  does  the  plant  raise  so  much  liquid  to  such 
a  ^considerable  height,  without  the  intervention 
of  any  visible  and  tangible  machinery? 

Two  main  agents  are  employed  for  this  pur- 
pose. The  one  is  known  as  root-pressure;  the 
other  as  evaporation. 

I  begin  with  the  former.  The  cells  of  which 
roots  are  made  up  are  most  ingeniously  con- 
structed so  as  to  exert  this  peculiar  form  of 
pressure.  Each  one  of  them  has  at  its  outer 
or  free  end,  where  it  comes  into  contact  with 
the  moist  earth,  a  wall  of  such  a  nature  that  it 
very  readily  absorbs  water,  and  allows  the  water 
so  absorbed  to  flow  freely  through  it  inward. 
But  once  in,  the  water  seems  almost  as  if 
imprisoned  in  a  pump  ;  it  cannot  pass  outward 
again,  only  inward  and  upward.  You  may 
compare  the  cell  in  this  respect  with  those 
mechanical  \^&*o$  which  yield  readily  to  the 
pressure  of  fluids  from  outside,  but  instantly  4 
close  when  a  fluid  from  inside  attempts  to  pass; 
through  them.  In  this  way  the  outer  cells  of* 
the  hairs  on  the  roots,  which  come  in  contact 
with  the  moistened  soil,  get  distended  with 
water,  and  swell  and  swell,  till  at  last  their 
walls  will  give  no  longer,  and  their  own  elas- 
ticity forces  the  water  out  of  them.  But  the 
water  cannot  flow  back  ;  so  it  has  to  flow  for- 
ward. Again,  each  cell  or  vessel  which  the 
stream  afterwards  enters  is  constructed  on  just 
the  same  general  principle  as  the  absorbent 


184  THE    STORY   OF   THE   PLANTS.. 

root-cells  ;  it  allows  water  to  pass  into  it  freely 
/from  below  upward,  but  does  not  allow  it  to 
vpass;  back  again  from  above  downward.  Thus 
we  get  a  constant  state  of  whiat  is  called 
tiirgidiiy  in  the  lower  cells ;  they  are  as  full  as 
they  can  hold,  and  they  keep  on  contracting 
elastically,  so  as  to  expel  the  water  they  contain 
into  other  cells  next  in  order  above  them.  By 
means  of  such  root-pressure,  as  it  is  called,  raw 
sap  is  being  for  ever  forced  up  from  the  soil 
beneath  into  the  stem  and  branches,  to  supply 
the  leaves  with  water  and  food-salts,  especially 
in  early  spring,  when  the  processes  of  growth 
are  most  active  and  vigorous. 

It  is  owing  to  this  peculiar  property  of  root- 
pressure  that  cut  stems  " bleed"  or  exude  sap, 
especially  in  spring-time.  The  root-pressure 
continues  of  itself  in  spite  of  the  fact  that  the 
stem  has  been  divided ;  and  the  sap  absorbed 
by  the  roots  is  thus  forced  out  at  the  other  end 
by  the  continuous  elasticity  of  the  cells  and 
vessels.  The  fact  that  severed  stems  will  thus 
"  bleed  "  or  exude  raw  sap  shows  in  itself  the 
reality  of  root-pressure. 

But  root-pressure  alone  would  not  fully  suffice 
to  r-aise  so  large  ft  bo4y  of  water  as  the  plant 
requires  \o>  SQ  great  a  hpigh^  above  the  earth's 
surface^  Jt  fs  therefore  largely  supplemented 
an4  assisted  by  the  second  or  subsidiary  power 
pf  evaporation.  This  evaporation,  QJC  "  transpi- 
ration "  as  it  is  generally  called,  is  just  as 
necessary  and  essential  to  plants  as  breathing 
is  to  men  and  animals. 

We  must  therefore  enter  a  little  more  fully 


THE    STEM    AND    BRANCHES.  185 

here  into  the  nature  of  so  important  and  uni- 
versal a  plant  function.  You  will  remember 
that  when  we  were  discussing  the  nature  of 
leaves,  I  gave  you  a  woodcut  of  a  thin  slice 
through  a  leaf  (Fig.  1)  which  showed  the  blade 
as  naturally  divided  into  an  upper  and  under 
portion.  The  upper  portion  consisted  of  very 
close-set  green  cells,  containing  living,  chloro- 
phyll, and  covered  by  a  single  transparent 
water-layer,  which  absorbed  carbonic  acid  from 
the  air  about,  and  passed  it  on  to  be  digested 
by  the  living  chlorophyll-layer  just  beneath  it. 
But  the  under  portion  was  sparse-looking  and 
spongy  ;  it  was  composed  of  cells  loosely 
arranged  among  themselves,  and  interspersed 
with  great  empty  spaces.  I  told  you  but  little 
at  the  time  of  the  function  or  use  of  this  lower 
portion  ;  we  must  return  to  it  now  in  the 
present  connection,  as  a  component  element  in 
the  task  of  water-supply. 

The  low£r  portion  of  most  leaves  is  the  part 
employeoin  the  great  and  necessary  work  of 
evaporation. 

For  this  purpose  the  tissue  at  the  under  side 
of  the  leaf  is  composed  of  loose  and  spongy  cells 
which  have  much  of  their  surface  exposed  to  the 
empty  spaces  between  them  :  and  these  empty 
spaces  are  really  air-cavities.  The  object  of  the 
cavities,  indeed,  is  to  facilitate  evaporation. 
Liquid  transpires  into  them  from  the  various 
cells  through  the  wall  that  bounds  them.  How 
fast  water  evaporates  in  the  leaves  of  plants  we 
all  know  by  experience  in  a  thousand  ways. 
We  know,  for  instance,  that  if  we  pick  bunches 


186       THE  STOKY  OF  THE  PLANTS. 

•of  flowers  and  leave  them  in  the  sun  without 
water,  they  fade  and  dry  up  in  a  very  short 
time.  We  also  know  that  if  we  forget  to  water 
plants  in  pots,  the  plants  similarly  dry  up 
and  die  after  a  few  hours'  exposure.  Leaves, 
in  fact,  are  purposely  arranged  in  most  cases 
so  as  to  encourage  a  very  rapid  evaporation ; 
and  evaporation  is  one  of  their  chief  means  of 
\aising  water  from  the  roots  to  the  growing  and 
living  portions. 

If  you  examine  the  under  side  of  a  leaf  under 
the  microscope,  you  will  find  it  is  covered  by 
hundreds  of  little  pores  which  look  exactly  like 
mouths,  and  which  are  guarded  by  two  cells 
whose  resemblance  to  lips  is  absurdly  obvious. 
These  pores  are  commonly  known  to  botanists 
by  the  awkward  name  of  stomata,  which  is  the 
Greek  for  mouths  ;  and  mouths  they  really  are 
to  all  external  appearance.  You  must  not 
suppose,  however,  that  they  are  truly  mouths 
in  the  sense  of  being  the  organs  with  which  the 
plant  eats ;  the  upper  surface  of  the  leaf,  as  we 
saw,  with  its  layer  of  water-cells  and  its  assimila- 
ting chlorophyll-bodies,  really  answers  in  the 
plant  to  our  mouths  and  stomachs.  The  stomata 
or  pores  are  much  more  like  the  openings  in 
the  skin  by  which  we  perspire  ;  only  perspira- 
tion or  evaporation  is  an  even  more  important 
part  of  life  to  the  plant  than.it  is  to  the  animal. 
Each  of  the  stomata  opens  into  an  air-cavity  ; 
and  through  it  the  liquid  evaporated  from  the 
cells  passes  out  as  vapour  into  the  open  air. 
Many  leaves  have  thousands  of  such  pores  on 
their  lower  surface ;  they  may  easily  be  recog- 


THE    STEM   AND    BBANCHES.  187 

nised  under  the  microscope  by  means  of  the 
curious  guard-cells  which  look  like  lips,  and 
which  give  the  pores,  in  fact,  their  strange 
mouth-like  aspect. 

What  is  the  use  of  these  lips  ?  Well,  they 
are  employed  for  opening  and  closing  the  evapo- 
rating pores,  or  stomata.  In  dry  weather  it  is  not 
desirable  that  the  pores  should  be  open,  for  then 
evaporation  should  be  limited  as  far  as  possible. 
So,  under  these  conditions,  the  lips  contract,  and 
the  pore  closes.  Excessive  evaporation  at  such 
times  would,  of  course,  damage  or  destroy  the 
Toliage  ;  the  plant  desires  rather  to  store  up  and 
retain  its  stock  of  moisture.  But  after  rain,  and 
in  damp  weather,  the  roots  suck  up  abundant 
water ;  and  then  it  becomes  desirable  that 
evaporation  should  go  on,  and  the  leaves  and 
growing  shoots  should  be  supplied  with  liquid 
food,  as  well  as  with  the  nitrogenous  matter  and 
salts  dissolved  in  it.  Hence  at  such  times  the 
pores  open  wide,  and  allow  the  water  in  the 
form  of  vapour  to  exude  from  them  freely. 

The  object  of  this  evaporation,  again,  is  two- 
fold. In  the  first  place,  it  supplements  root- 
pressure  as  a  means  of  raising  water  to  the 
leaves  and  growing  shoots ;  and  in  the  second 
place,  by  getting  rid  of  superfluous  liquid,  it 
leaves  the  nitrogenous  material  and  the  food- 
salts  in  a  more  concentrated  form,  at  the  very 
points  where  they  are  just  then  needed  for  the 
formation  of  fresh  living  protoplasm  and  other  / 
useful  constructive  factors  of  plant-life.  But  how 
does  evaporation  raise  water  from  the  ground  ? 
In  this  way.  The  living  contents  of  each  cell 


188       THE  STORY  OF  THE  PLANTS. 

on  the  upward  path  have  a  natural  chemical 
affinity  for  water,  and  will  suck  it  up  greedily 
wherever  they  can  get  it.  Thus  each  part,  as 
fast  as  it  loses  water  by  evaporation,  takes  up 
more  water  in  turn  from  its  next  neighbour 
below ;  and  that  once  more  withdraws  it  from 
the  cell  beneath  it ;  and  so  on  step  by  step  until 
we  reach  the  actual  absorbent  root-hairs.  Eoot- 
pressure  by  itself  could  not  raise  water  as  high 
as  we  often  see  it  raised  in  great  forest  trees  and 
tropical  climbers ;  it  has  not  enough  mechanical 
motor  power.  But  here  evaporation  comes  in, 
to  aid  it  in  its  task ;  and  the  real  motor  power 
in  this  last  case  is  the  very  potent  force  of 
chemical  attraction. 

What  I  have  said  here  about  evaporation,  and 
the  way  it  is  conducted  by  means  of  pores  on  the 
surface  of  the  leaves,  is  true  of  the  vast  majority 
of  green  plants ;  but  considerable  varieties  and 
modifications  occur,  of  course,  in  accordance 
with  the  necessities  of  various  situations.  For 
example,  the  brooms  and  many  other  shrubs  of 
the  same  twiggy  type  have  few  green  leaves,  but 
in  their  stead  produce  lithe  green  stems,  filled 
with  active  chlorophyll.  These  stems  and 
branches  do  all  the  work  usually  performed 
by  ordinary  foliage.  Stems  and  twigs  of  this 
type  are  covered  with  mouth-like  pores,  or 
stomata,  in  exactly  the  same  way  as  the  under 
side  of  leaves  in  most  other  species.  Similarly, 
the  very  flattened  leaf-like  branches  of  the 
butcher's  broom,  and  of  the  Australian  aca- 
cias and  other  Australasian  trees,  are  well 
supplied  with  like  pores  for  purposes  of  evapora- 


STEM  AND   BHANCHEg.  189 

tion.  Again,  while  the  pores  are  usually  found 
on  the  under  surface  of  the  leaf,  they  are  situated 
on  the  upper  surface  of  leaves  which  float  on 
water,  like  the  water-lily  and  the  water-crow- 
foot ;  because  in  such  plants  they  would  be 
obviously  useless  for  purposes  of  evaporation  on 
the  lower  side,  which  is  in  contact  with  the 
water.  Some  leaves  have  the  stomata  on  both 
sides  alike,  especially  when  no  one  side  is  much 
more  exposed  to  sunlight  than  another.  But 
wherever  they  are  found,  they  always  lie  above 
masses  of  loose  and  spongy  cell-tissue,  in  whose 
meshes  and  air-spaces  evaporation  can  go  on 
readily. 

On  the  other  hand,  as  I  noted  before,  leaves 
which  grow  in  very  dry  or  desert  situations 
require  as  much  as  possible  to  curtail  evapo- 
ration. Such  leaves  are  therefore  usually  thick 
and  fleshy,  and  possess  a  very  small  allowance 
of  pores.  The  forms  of  several  leaves,  again, 
are  largely  dependent  upon  the  necessity  for 
keeping  the  pores  free  from  wetting,  and  pro- 
moting evaporation  whenever  it  is  needful  for 
the  plant's  health  and  growth ;  and  this  is 
particularly  the  case  with  what  are  called 
"rolled  leaves,"  such  as  one  sees  in  the 
heaths  and  the  common  rock-roses.  Many  such 
additional  principles  have  always  to  be  taken 
into  consideration  in  attempting  to  account  for 
the  various  shapes  of  foliage  :  indeed,  we  can 
•only  rightly  understand  the  form  of  any  given  leaf 
when  we  know  all  about  its  habits  and  its  native 
situation. 

The  stem,  then,  besides  raising  the  leaves  and 


190  THE    StOKY   OF   THE    t>LANT3. 

flowers,  for  which  purpose  it  is  often  streng- 
thened by  means  of  mechanical  woody  tissue, 
also  acts  as  a  conductor  of  raw  sap  from  the  tips 
of  the  roots  to  the  leaves  and  growing  points, 
for  which  purpose  it  is  further  provided  with  an 
elaborate  system  of  canals  and  vessels,  running 
direct  from  the  absorbent  root  to  all  parts  of  the 
compound  plant  community. 

The  third  function  of  the  stem  and  branches 
is  to  convey  and  distribute  the  elaborated  pro- 
ducts of  plant-chemistry  and  plant-manufacture 
from  the  places  where  they  are  made  to  the 
places  where  they  are  needed  for  practical 
purposes. 

I  We  saw  long  since  that  starches,  sugars,  pro- 
toplasms, and  chlorophyll  are  manufactured  in 
the  leaves  under  the  influence  of  sunlight ;  and 
from  the  materials  so  manufactured  every  part 
of  the  plant  must  ultimately  be  constructed. 
But  we  never  said  a  word  at  the  time  about  the 
means  by  which  the  materials  in  question  were 
carried  about  and  distributed  to  the  various 
organs  in  need  of  them.  Nevertheless,  a  mo- 
ment's consideration  will  show  you  that  new 
leaves  and  shoots  must  necessarily  be  built  up 
at  the  expense  of  materials  supplied  by  the 
older  ones  ;  that  flowers,  fruits,  and  seeds  must* 
be  constructed  from  protoplasm  handed  over 
for  their  use  by  the  neighbouring  foliage.  Nay 
more  ;  the  root  itself  grows  and  spreads ;  and 
the  very  tips  of  the  roots,  which  themselves^f 
course  can  manufacture  nothing,  must  be  sup- 
plied  from, above. with  most  active  and  discrimi- 


THE    STEM    AND    BRANCHES.-  I9l 

hating  protoplasm,  to  guide  their  ffioVements. 
Whence  do  they  get  it  ?  From  the  factory  in 
the  foliage.  Thus,  from  the  summit  of  the  tallest 
tree  down  to  the  lowest  root  that  fastens  it  in 
the  soil,  there  runs  a  complex  system  of  pipes 
and  tubes  for  the  special  conveyance  of  elaborated 
material ;  and  this  system  supplies  every  grow- 
ing part  with  the  food- stuff  necessary  for  its 
particular  growth,  and  every  living  part  with  the 
food-stuff  necessary  for  maintaining  its  life  and 
activity,  An  interchange  of  protoplasmic  matter, 
starches,  and  sugars,  goes  on  continually  through 
the  entire  organism. 

This  downwar^^d  fmf.wa.rrl  stream  of  living  \  / 
matter,  carrying  along  with  it  live  protoplasm 
and  other  foods  or  manufactured  materials,  must 
be    carefully    distinguished    from    the    upward 
stream  of  crude  sap  which  rises  from  the  roots  ' 
to  the  leaves  and  branches.     The  one  contains 
only  such  raw  materials  of  life  as  are  supplied 
by  the  soil — namely,  nitrogenous  matter,  water, 
and   food-saltst;    the  other  contains  the  things 
eaten  from  the  air  by  the  plant  in  its  leaves,  I 
and  afterwards  worked  up   by  it   into   sugars,/  £• 
starches,  protoplasm,  and  chlorophyll. 

Stems  are  usually  covered  outside  for  purposes 
of  protection  by  a  more  or  less  thick  integument, 
which  in  trees  and  shrubs  assumes  the  corky 
form  we  know  as  bark.  Bark  consists  of  d,eacl 
and  empty  cells,  thickened  with  a  lighter 
thickening  matter  than  wood,  and  presenting 
as  a  rule  a  rather  spongy  appearance.  But 
beneath  the  bark  comes  a ^i^nci^_layer_Qf  living 


192  THE   STOftY    OF   Tftfc   PLANTS. 

material,  interposed  between  the  corky  dead  I 
cells  of  the  integument  and  the  woody  dead  • 
cells  of  the  interior.  This  living  layer  extends 
over  stem,  twigs,  and  branches :  it  forms  the 
binding  and  connecting  portion  of  the  entire 
plant  community  ;  it  links  together  in  one  united 
/whole  the  living  material  of  the  leaves,  and  shoots 
v  \with  the  living  material  of  the  roots  arid  rootlets. 
It  is  thus^the  stem,  above  all,  that  gives  to  the 
complex  plant  colony  of  foliage  and  flowers 
whatever  organic  unity  and  individuality  it  ever 
possesses. 

All  situations,  however,  are  not  alike.  Just 
as  here  this  sort  of  leaf  succeeds,  and  there  that, 
so  in  stems  and  branches,  here  this  form  does 
best,  and  there  again  the  other.  The  shape  of 
the  stem  and  branches,  in  fact,  is  the  shape  of 
the  entire  plant  colony ;  and  it  is  arranged  to 
suit,  on  the  average  of  instances,  the  convenience 
of  all  its  component  members.  Much  depends 
on  the  shape  of  the  leaves ;  much  on  the  condi- 
tions of  wind  or  calm,  shade  or  sunshine. 

Some  plants  are  annuals.  These  require  no 
large  and  permanent  stem  ;  they  spring  from 
the  seed  each  year,  like  peas,  or  wheat,  or 
poppies ;  they  make  a  stem  and  leaves ;  they 
produce  their  flowers ;  they  set,  and  ripen,  and 
scatter  their  seed ;  and  then  they  wither  away 
and  are  done  with  for  ever.  Hundreds  of  such 
plants  occur  in  our  fields  and  gardens.  Even 
these  annuals,  however,  differ  greatly  in  the 
amount  of  their  stem  and  branches.  Some 
are  quite  low,  humble,  and  succulent,  like 


THE    STEM   AND    BRANCHES.  193 

chickweed  and  sandwort ;  others  have  tall  and 
comparatively  stout  stems,  like  wheat,  oats,  and 
barley,  or  still  more,  like  the  sunflower.  As  a 
rule,  annuals  are  not  very  large  ;  but  a  few  rich 
seeds  produce  strong  young  plants  which  even 
within  a  single  year  attain  an  astounding  size ; 
this  is  the  case  with  the  garden  poppy,  the 
tobacco  plant,  and  the  Indian  corn,  and  even 
more  so  with  certain  climbing  annuals,  such  as 
the  gourd,  the  cucumber,  the  melon,  and  the 
pumpkin. 

Many  plants,  however,  find  it  pays  them  better 
to  produce  a  hard  and  woody  stem,  which  lasts 
from  year  to  year,  and  enables  them  to  put  forth 
fresh  leaves  and  shoots  in  each  succeeding 
season.  Among  these,  again,  great  varieties 
exist.  Some  have  merely  a  rather  short  and 
stout  stem  with  many  bundles  of  water-vessels, 
as  in  the  pink  and  the  wallflower.  Their  growth 
is  herbaceous.  Others,  however,  produce  that 
more  solid  form  of  tissue  which  we  know  as 
wood,  and  which  is  made  up  of  cells  whose  walls 
have  become  much  thickened  and  hardened. 
Among  the  woody  group,  again,  we  may  dis- 
tinguish many  intermediate  varieties,  from  the 
mere  shrub  or  bush,  like  the  heath  and  the 
broom,  through  small  trees  like  the  rhodo- 
dendron, the  lilac,  the  hawthorn,  and  the  holly, 
to  such  great  spreading  monsters  of  the  forest  as 
the  oak,  the  ash,  the  pine,  the  chestnut,  and  the 
maple. 

Once  more,  some  plants  produce  an  under- 
ground stem,  and  send  up  from  this  fresh  annual 
branches.     That   is  the   case   with  hops,   with 
13 


194        THE  STORY  OF  THE  PLANTS. 

meadow-sweet,  and  with  buttercup,  as  well  as 
with  many  of  our  garden  flowers.  When  a 
plant  becomes  perennial,  it  is  a  mere  question  of 
its  own  convenience  whether  it  chooses  to  produce 
a  thick  and  woody  stem,  like  trees  and  bushes, 
or  to  lay  up  material  in  underground  roots, 
stocks,  and  branches,  like  the  potato,  the  dahlia, 
the  lilies,  the  bulbous  buttercup,  the  crocus,  the 
iris,  the  Jerusalem  artichoke,  and  the  meadow 
orchis. 

Ordinary  people  divide  most  plants  into  three 
groups — herbs,  shrubs,  and  trees.  But  I  think 
you  will  have  seen  from  what  I  have  just  said, 
that  in  every  great  family  of  plants  different  kinds 
have  found  it  worth  while  to  adopt  any  one  of 
these  forms  at  will,  according  to  circumstances. 
Trees,  in  other  words,  do  not  form  a  natural 
group  by  themselves  ;  any  family  of  plant  may 
happen  to  develop  a  tree-like  species.  Thus 
the  herb-like  clover  and  the  tall  tree-like  labur- 
num are  closely  related  peaflowers.  Most  of 
the  composites  are  mere  herbs  or  shrubs,  but  a 
very  few  of  them  in  the  South  Sea  Islands  have 
grown  into  large  and  much-branched  trees.  The 
grasses  are  mainly  herbs ;  but  some  of  them, 
like  the  bamboos,  have  developed  tall  and  tree- 
like stems,  much  branched  and  feathery. 

Take  the  single  family  of  the  roses,  for  example, 
so  familiar  to  most  of  us ;  some  of  them  are  mere 
annual  weeds,  like  the  tiny  parsley-piert  that 
occurs  as  a  pest  in  every  garden.  Others,  again, 
are  perennials  with  low  tufted  stems,  like  the 
strawberry  ;  or  creeping,  like  the  cinquefoil ;  or 
rising  into  a  spike,  like  the  burnet  and  the  agri- 


THE    STEM   AND    BKANCHES.  195 

mony.  Yet  others  become  scrambling  bushes, 
like  the  blackberry  and  the  raspberry.  In  the 
blackthorn  and  the  hawthorn  the  bush  has 
become  more  erect  and  tree-like.  Both  types  of 
growth  occur  in  the  dog-rose  and  many  other 
roses.  The  cherry  attains  the  size  and  etature 
of  a  small  tree.  The  mountain-ash  is  bigger ; 
the  apple-tree  bigger  still ;  while  the  pear  often 
grows  to  a  considerable  height  and  much  spread- 
ing dignity.  These  are  all  members  of  the  rose 
family.  Here,  therefore,  every  variety  of  shape 
and  size  is  well  represented  within  the  limits  of 
a  single  order. 

One  word  must  be  given  to  the  varieties  of  the 
stem.  Sometimes,  as  in  the  oak,  the  trunk  is 
much  branched  and  intricate ;  sometimes,  as  in 
the  date-palm,  simple  and  unbranched,  bearing 
only  a  single  tuft  of  circularly  arranged  leaves. 
But  the  most  interesting  in  this  respect  are  the 
climbing  and  twisting  stems,  which  do  not  take 
the  trouble  to  support  themselves,  but  lean  for 
aid  upon  the  trunk  of  some  stronger  and  more 
upright  neighbour.  Stems  of  this  sort  are 
familiar  to  us  all  in  the  hop  and  the  bindweed. 
In  other  climbers  the  stems  do  not  twine  to  any 
great  extent,  but  the  plants  support  themselves 
by  root-like  processes,  as  in  ivy,  or  by  tendrils, 
as  in  the  vine,  or  by  twisted  leaf-stalks,  as  in 
the  canary  creeper.  Others  cling  by  means  of 
suckers,  as  the  Ampelopsis  Veitchii,  or  hang  by 
opposite  leaves,  like  clematis,  or  cling  by  hooked 
hairs,  as  is  the  case  with  cleavers.  In  certain 
instances,  such  creeping  or  climbing  plants  tend 
to  become  parasitic — that  is  to  say,  they  fasten 


196        THE  STOKY  OF  THE  PLANTS. 

themselves  by  sucker-like  mouths  to  the  bark  of 
the  harder  plant  up  which  they  climb,  and  feed 
upon  its  already  elaborated  juices.  Our  English 
dodder  is  an  example  of  such  a  plant.  It  has  no 
leaves  of  its  own,  but  consists  entirely  of  a  mass 
of  red  stems,  bearing  clusters  of  pretty  pale  pink 
flowers. 

Other  plants  show  another  form  of  parasitism. 
Misletoe  is  one  of  these.  It  fastens  itself  to  a 
poplar  or  an  apple-tree  (very  seldom  an  oak)  and 
sucks  its  juices.  But  it  has  also  green  leaves  of 
its  own,  which  do  real  work  of  eating  and 
assimilating  as  well.  It  is  therefore  not  quite 
such  a  parasite  as  the  dodder.  Several  plants 
are  similarly  half-parasitic  on  the  roots  of  wheat 
and  grasses.  Among  them  I  may  mention,  as 
English  instances,  the  cow-wheat,  the  yellow 
rattle,  and  the  pretty  little  eyebright. 

Broomrape  is  a  parasite  of  a  different  sort.  It 
grows  on  the  roots  of  clover,  and  has  no  true 
leaves ;  in  their  place  it  produces  short  scales, 
which  contain  no  chlorophyll.  Several  other 
plants  are  also  devoid  of  chlorophyll,  and  there- 
fore cannot  eat  carbonic  acid,  for  themselves. 
They  live  like  animals  on  materials  laid  by  for 
them  by  other  plants.  Such  are  toothwort,  a 
pale  rose-coloured  leafless  plant,  with  pretty 
spiked  flowers,  which  grows  by  suckers  on  the 
roots  of  hazel-trees.  The  bird's  nest  orchid,  a 
delicate  brown  plant  with  curious  ghost-like 
blossoms,  feeds  rather  on  the  organised  matter 
in  decaying  leaves  among  thick  beechwoods.  In 
this  book  I  have  purposely  confined  your  atten- 
tion for  the  most  part  to  the  true  green  plants, 


THE    STEM   AND    BKANCHES.  197 

which  are  the  central  and  most  truly  plant-like 
type ;  but  I  ought  to  tell  you  now  that  a  great 
many  plants,  especially  among  the  lower  kinds, 
behave  in  this  respect  much  more  like  animals  : 
instead  of  manufacturing  fresh  starches  and 
protoplasms  for  themselves  from  carbonic  acid, 
under  the  influence  of  sunlight,  they  eat  up 
what  has  already  been  made  by  other  and  more 
industrious  species.  Such  plants  are  retrograde. 
They  are  products  of  degeneracy.  Amoiign&hem 
I  may  specially  mention  all  the  fungi,  like  mush- 
rooms, toadstools,  mould,  and  mildew,  as  well  as 
the  bacilli  and  bacteria,  microscopic  and  de- 
generate plants  which  cause  decomposition. 
Their  life  is  more  like  that  of  animals  than  of 
true  vegetables. 

In  tropical  forests,  where  the  soil  is  almost 
monopolised  by  huge  spreading  trees,  the  smaller 
plants  have  been  forced  to  secure  their  fair  share 
of  light  and  air  by  somewhat  different  means 
from  those  which  are  common  in  cooler  climates. 
Many  of  them,  without  being  parasitic,  have 
learnt  to  attach  themselves  by  their  roots  to  the 
outer  bark  of  the  trees,  and  so  to  get  at  the 
light,  no  ray  of  which  ever  struggles  through  the 
living  canopy  of  green  in  the  dense  jungle. 
These  plants  have  green  leaves,  and  eat  for 
themselves ;  but  they  use  the  boughs  of  their 
host  instead  of  soil  to  root  themselves  in.  Such 
plants  are  technically  known  as  epiphytes.  This 
is  the  mode  of  life  of  most  of  the  handsome 
orchids  cultivated  in  our  conservatories. 

Now  let  us  recapitulate.     The  stem  unites  the 


198       THE  STORY  OF  THE  PLANTS. 

various  parts  of  the  plant — the  root,  the  leaves, 
the  flowers,  the  fruit.  It  conducts  water  and 
nitrogenous  matter  from  the  soil  to  the  foliage. 
It  also  carries  the  manufactured  materials  from 
the  points  where  they  are  made  to  the  points 
where  they  are  wanted  for  the  growth  of  fresh 
organs.  It  supports  and  raises  the  whole  plant 
colony.  Finally,  it  stores  up  material  in 
drought  or  winter,  which  it  uses  for  new 
branches,  leaves,  or  flowers,  when  rain  or 
spring  or  favourable  conditions  in  due  time 
come  round  again. 


CHAPTEE   XIII. 

SOME    PLANT    BIOGRAPHIES. 

WE  have  considered  so  far  the  various  elements 
which  go  to  make  up  the  life  of  plants — how 
they  eat  and  drink,  how  they  digest  and  assimi- 
late, how  they  marry  and  get  fertilised,  how  they 
produce  their  fruit  and  set  their  seeds,  finally 
how  they  are  linked  together  in  all  their  parts 
by  stem  and  vessels  into  a  single  community. 
But  up  to  the  present  moment  we  have  con- 
sidered these  elements  in  isolation  only,  as  so 
many  processes  the  union  of  which  makes  up 
what  we  call  the  life  of  an  oak,  or  a  lily,  or 
a  strawberry  plant.  In  order  really  to  under- 
stand how  all  these  principles  work  together  in 
practical  action,  we  ought  to  take  a  few  specimen 
lives  of  real  concrete  plants,  and  trace  them 
through  direct,  from  the  cradle  to  the  grave, 


SOME   PLANT   BIOGRAPHIES.  199 

with  all  their  vicissitudes.  I  propose,  therefore, 
in  this  chapter  to  give  you  brief  sketches  of  one 
or  two  such  life-histories  ;  and  I  hope  these  few 
hints  may  encourage  you  to  find  out  many  more 
for  yourself,  by  personal  study  of  plants  in  their 
native  surroundings. 

"  In  their  native  surroundings,"  I  say,  since 
all  life  is  really,  in  Mr.  Herbert  Spencer's  famous 

*  phrase,  "  adaptation  to  the  environment ;  "  and 

*  therefore  we  can  only  understand  and  discover 
the  use  and  meaning  of  each  part  or  organ  by 
watching  the  plant  in  its  own  home,  and  among 
the    general    conditions    by    which    it   and   its 
ancestors  have  always  been  limited.     It  would 
be   impossible,  for  example,  to  see  the  use   of 
the  thick  outer  covering  of  the  coconut    (from 
which  coconut  matting  is  manufactured)  if   we 
did  not   know   that   the    coconut    palm   grows 
naturally  by  the  sea  shore  in  tropical  islands, 
and  frequently  drops  its   fruits  into  the  water 
beneath  it.     The  nuts  are  thus  carried  by  the 
waves   and   currents   from   islet    to    islet  ;    and 
the  coconut  palm,  which  is  a  denizen  of   sea- 
sand,    owes  to  this   curious   method   of  water- 
carriage  its  wide  dispersion  among  the  coral-reefs 
of  the  Pacific.     But  a  plant  that  is  so  dispersed 
must    needs   make    provision   against    wetting, 
bruising,  and  sinking  in  the  sea  ;  and  since  only 
those   coconuts  would  get  dispersed  over  wide 
spaces  of  water  which  happened  to  possess  a 
good  coating  of  fibre,  the  existing  plant  has  come 
to  produce  the  existing  nut  as  we  know  it — richly 
stored   with  food  for  the  young  palm  while  it 
makes  its  first  steps  among  the  barren  rocks  and 


200       THE  STOBY  OF  THE  PLANTS. 

sand-banks,  and  well  provided  by  its  shaggy 
outer  coat  against  the  dangers  of  the  sea,  the 
reefs,  and  the  breakers.  Similarly,  we  could 
never  understand  the  cactus  except  as  a  native 
of  the  dry  plains  of  Mexico.  Or  again,  there  is 
an  orchid  in  Madagascar  with  a  spur  containing 
honey  at  a  depth  of  eighteen  inches.  Now,  no 
European  insect  could  possibly  reach  so  deep  a 
deposit ;  but  a  Madagascar  moth  has  a  gigantic 
proboscis,  exactly  fitted  for  sucking  the  nectary 
and  fertilising  the  flowers.  Thus  no  plant  can 
properly  be  understood  apart  from  its  native 
place ;  and  I  have  therefore  confined  myself  for 
the  most  part  in  these  few  brief  life-histories  to 
native  British  plants,  whose  circumstances  and 
surroundings  are  known  to  everybody. 

As  an  example  of  a  very  simple  and  easy  life- 
history,  I  will  take  first  a  little  wayside  weed, 
commonly  known  as  whitlow-grass,  but  called 
by  botanists,  in  their  scientific  Latin,  Draba 
rcrna.  This  curious  little  herb  is  not  a  grass  at 
all  (as  its  name  might  make  you  think),  but  a 
member  of  the  great  family  of  the  crucifers, 
succulent  plants  with  four  petals  and  six  stamens 
in  each  flower,  to  which  the  cabbage,  the  turnip, 
the  sea-kale,  and  many  other  well-known  garden 
species  belong.  But  whitlow-grass  is  not  a  large 
and  conspicuous  plant  like  any  of  these  ;  it  is  one 
of  the  smallest  and  shortest-lived  of  our  British 
weeds.  It  has  managed  to  carve  itself  out  a 
place  in  nature  on  the  dry  banks  and  in  clefts  of 
rock  during  the  few  weeks  in  spring  while  such 
spots  are  as  yet  unoccupied  by  more  permanent 
denizens.  The  herb  starts  from  a  very  minute 


SOME    PLANT   BIOGRAPHIES.  201 

seed,  dropped  on  the  soil  by  the  parent  plant 
many  months  before,  and  patiently  waiting  its 
time  to  develop  till  winter  frosts  are  over,  and 
warmer  weather  and  moisture  begin  to  quicken 
its  tiny  seed-leaves.  As  soon  as  these  have 
opened  and  used  up  their  very  small  stock  of 
internal  nutriment,  the  young  plant  begins  to 
produce  on  its  own  account  a  rosette  of  little 
oblong  green  leaves,  pressed  close  to  the  ground 
for  warmth  and  shelter.  They  eat  as  they  go, 
and  make  fresh  leaves  again  out  of  the  absorbed 
and  assimilated  material.  Direct  sunshine  falls 
upon  them  full  front ;  and  as  no  other  foliage 
overshadows  them  or  competes  in  their  neigh- 
bourhood for  carbonic  acid,  they  grow  apace  into 
a  little  tuft  of  spreading  leaves,  about  half  an 
inch  long  or  less,  and  forming  in  the  mass  a 
rough  circle.  For  about  a  week  or  ten  days  the 
little  mouths  go  on  drinking  in  carbonic  acid  as 
fast  as  they  can,  and  manufacturing  it  under  the 
influence  of  sunlight  into  starches  and  proto- 
plasm. At  the  did  of  that  time  they  have 
collected  enough  material  to  send  up  a  slender 
blossoming  stem,  about  an  inch  high  or  more, 
bearing  no  leaves,  but  developing  at  the  top  a 
few  tiny  flower-buds.  These  shortly  open  and 
display  their  flowers,  very  small  and  incon- 
spicuous, with  four  wee  white  petals,  each  so 
deeply  cleft  that  they  resemble  eight  to  a  casual 
observer.  Inside  the  petals  are  six  little  active 
stamens ;  and  inside  the  stamens  again  a  two- 
celled  ovary.  The  blossoms  are  visited  and 
fertilised  on  warm  March  mornings  by  small 
spring  midges,  attracted  by  the  petals.  They 


202       THE  STOBY  OF  THE  PLANTS. 

immediately  set  their  seeds  in  the  flat  green 
capsule,  ripen  them  rapidly  in  the  eye  of  the 
sun,  and  shed  them  at  once,  the  whole  life  of  the 
plant  thus  seldom  exceeding  three  or  four  weeks 
in  a  favourable  season.  At  the  same  time,  the 
leaves  and  roots  wither,  as  the  material  they 
contained  is  rapidly  withdrawn  from  them,  and 
used  up  in  the  process  of  maturing  the  seeds ;  so 
tlfat  as  soon  as  the  fruiting  is  quite  complete, 
the  plant  dies  down,  having  exhausted  itself 
utterly  in  the  two  short  acts  of  flowering  and 
seed-bearing.  During  the  remaining  ten  months 
of  the  year  or  thereabouts,  there  are  no  more 
whitlow-grasses  at  all  in  existence ;  the  species 
remains  dormant,  as  it  were,  for  a  whole  long 
period  in  the  form  of  seeds  lying  buried  in  the 
soil,  and  only  springs  to  life  again  when  the 
return  of  March  gives  it  warning  that  its  day 
has  once  more  come  round  to  it. 

Contrast  with  this  brief  and  very  spasmodic 
life  of  some  thirty  days  the  comparatively  long 
though  otherwise  extremely  similar  biography 
of  the  Mexican  agave,  commonly  cultivated  in 
hothouses  in  England,  and  largely  grown  in 
the  open  air  in  the  South  of  Europe  under 
the  (incorrect)  name  of  "  American  aloes." 
The  agave  is  a  large  and  strikingly  handsome 
lily  of  the  amaryllis  family,  about  which  I  have 
already  told  you  something  in  a  previous  chapter. 
It  begins  life  as  a  small  plant,  like  a  London 
pride,  springing  from  a  comparatively  large  and 
richly-stored  seed  on  its  own  dry  prairies.  Its 
leaves,  which  spread  in  a  rosette,  are  not  unlike 
those  of  the  house-leek  in  shape ;  they  are  very 


SOME    PLANT   BIOGRAPHIES.  203 

large,  thick,  and  fleshy.  But  as  they  grow  in 
the  hot  and  dry  climate  of  Mexico,  an  almost 
desert  country,  with  a  very  small  rainfall,  they 
have  a  particularly  hard  outer  skin,  so  as  to 
prevent  undue  evaporation ;  and  they  are  pro- 
tected against  the  attacks  of  herbivorous  animals 
by  being  spiny  at  the  edges,  and  ending  in 
a  stout  and  dagger-like  point  of  the  most  for- 
midable description.  The  centre  of  the  plant 
is  occupied  by  a  sort  of  sheath  of  leaves,  con- 
cealing the  growing  point.  For  several  years 
the  round  bunch  of  outer  leaves  grows  bigger 
and  bigger,  till  it  attains  a  diameter  of  ten  or 
fifteen  feet  at  the  base,  seeming  still  like  a  huge 
rosette,  with  hardly  any  visible  stem  to  speak  of. 
Meanwhile  these  huge  leaves  are  busy  all  the 
time,  eating  and  assimilating,  and  storing  up 
manufactured  food- stuffs  as  hard  as  they  can  in 
their  thick  and  swollen  bases.  After  six  or 
seven  years  in  their  native  climate,  the  plant  feels 
itself  in  a  position  to  send  up  a  flowering  stalk, 
which  is  formed  from  the  materials  already  laid 
by  in  these  immensely  thick  and  richly-stored  leaf 
bases.  The  stalk  springs  from  the  middle  of  the 
central  leaf-sheath.  In  a  very  few  weeks  the 
agave  has  sent  up  from  this  point  a  huge  flower- 
ing scape,  twenty  or  thirty  feet  high,  and  a  foot 
or  fifteen  inches  thick  at  the  bottom.  On  this 
scape  it  produces  with  extraordinary  rapidity  a 
vast  number  of  large  and  showy  yellow  flowers, 
which  look  not  unlike  an  enormous  candelabrum, 
with  many  divided  branches.  The  plant  is 
enabled  to  produce  this  immense  flowering  stem 
and  these  numerous  flowers  in  so  short  a  period, 


204       THE  STORY  OF  THE  PLANTS. 

because  it  draws  upon  its  large  store  of  elabo- 
rated material  for  the  purpose.  But  as  the 
flowering  stem  rises,  and  the  flowers  unfold,  and 
the  big  fruits  and  seeds  develop  and  ripen,  the 
leaves  below  grow  gradually  flaccid  and  empty  ; 
and  their  bases  shrink,  being  depleted  of  their 
store  of  valuable  food-stuffs ;  so  that  by  the  time 

[  the  seeds  are  ripe,  the  whole  plant  is  used  up, 
having  exhausted  itself,  like  the  tiny  whitlow- 

)  grass,  in  the  act  of  fruiting.  It  then  dies  down 
altogether,  and  never  recovers,  though  new 
plants  or  offsets  usually  develop  at  its  base  from 
side  buds,  after  the  original  agave  has  begun  to 
wither.  In  English  hothouses  it  takes  thirty 
or  forty  years  before  the  agave  has  collected 
enough  material  to  send  up  a  stem  and  flower  ; 
hence  the  common  exaggeration  that  it  needs  a 
hundred  years  for  "  the  blossoming  of  an  aloe." 

As  a  familiar  example  of  a  very  different  kind 
of  perennial  plant,  we  may  take  our  English 
beech- tree.  The  beech  sets  out  in  life  as  a 
tender  young  seedling,  which  grows  from  a  good- 
sized  triangular  nut,  whose  cotyledons  are  well- 
stored  with  food- stuffs  for  its  early  development. 
As  the  nut  germinates,  the  cotyledons  open  out, 
become  flat  and  green,  like  thick  fleshy  leaves, 
and  begin  to  absorb  carbonic  acid  from  the  air, 
which  they  work  up  at  once  with  the  material 
supplied  by  the  tiny  root  into  protoplasm  and 
chlorophyll.  In  the  angle  between  them  a  young 
shoot  develops,  which  soon  puts  forth  delicate 
blades  of  true  foliage  leaves  ;  and  these  in  turn 
grow  and  assimilate  material  under  the  influence 
of  sunlight.  In  the  first  year  the  little  beech-tree 


SOME    PLANT    BIOGRAPHIES.  205 

is  but  a  tiny  sapling,  with  a  short  stem,  already 
woody ;  but  year  after  year,  this  stem  grows 
higher,  branches  out  and  divides,  and  slowly 
clothes  itself  in  the  smooth  grey  bark  charac- 
teristic of  the  species.  The  particular  way  in 
which  it  branches  is  this  :  each  autumn  there  is 
formed  at  the  base  of  every  leaf  a  winter  bud, 
long  and  brown,  and  covered  with  close  scales, 
which  enable  it  to  survive  the  cold  of  winter. 
When  spring  comes  round  again,  each  one  of 
these  buds  develops  in  turn  into  a  leafy  branch, 
so  that  (accidents  excepted)  there  are  as  many 
new  branches  or  twigs  every  year  as  there  were 
leaves  on  the  tree  in  the  preceding  season.  The 
young  leaves  and  branches  emerge  slowly  and 
cautiously  from  the  buds  in  spring,  for  fear  of 
frost ;  they  are  protected  at  first  by  certain  scaly 
brown  coverings  known  as  stipules.  Gradually, 
however,  as  the  weather  grows  warmer,  the 
stipules  fall  off,  and  display  the  tender  green 
leaves,  exposed  to  the  air,  but  still  folded  to- 
gether. As  soon  as  they  car*,  trust  the  season, 
however,  the  leaves  unfold,  though  they  are  still 
thickly  covered  at  the  edges  by  protective  hairs, 
which  afterwards  fall  off,  but  which  guard  the 
fresh  green  chlorophyll  in  the  cells  just  at  first 
both  from  chilly  winds  and  from  the  injurious 
effect  of  excessive  sunlight.  Year  after  year 
the  beech-tree  grows  by  so  subdividing  and 
adding  branch  to  branch ;  while  its  stem  in- 
creases by  yearly  rings  of  growth,  till  it  attains 
at  length  considerable  dimensions. 

During   many  such   seasons   of    growth    the 
beech-tree  does  not  flower ;  all  the  material  it 


206       THE  STORY  OF  THE  PLANTS. 

manufactures  through  the  summer  in  its  large 
flat  leaves  it  lays  by  in  its  stem  to  supply  the 
young  shoots  and  branches  at  the  beginning  of 
the  subsequent  season.  But  at  last,  when  it  has 
reached  the  height  and  girth  of  a  small  tree,  it 

/  begins  to  store  up  protoplasm  and  starches  for 
blossom  also.  Some  of  its  buds  are  now  leaf- 

"buds,  but  some  are  flower-buds,  produced  in 
autumn,  and  held  over  till  April.  In  the  spring 
these  flower-buds  lengthen  and  produce  bunches 
of  blossoms,  which  we  call  catkins,  some  of 
them  males,  and  some  females,  but  both  sexes 
growing  on  the  same  tree  together.  They 
bloom,  like  most  otEer  catkins,  in  the  early 
spring,  while  the  leaves  are  still  very  little 
developed,  so  as  to  prevent  the  foliage  from 
interfering  with  the  carriage  of  the  pollen.  The 
males  are  produced  in  hanging  clusters  an  inch 


.  or  so  long  ;  while  the  females  stand  u^  in  small 
globular  bunches,  on  erect  flower^sTems.  They 
are  wind-fertilised ;  and  shortly  after  flowering, 
the  male  catkins  d.rop  off  entire,  having  done 
their  life-work,  while  the  females  swell  out  into 
the  familiar  husks  or  four-valved  cups,  con- 
taining each  some  two  or  three  triangular 
nuts,  richly  stored  with  food-stuffs. 

The  agave  only  flowers  once,  and  then  dies 
down,  exhausted.  But  the  beech  goes  on 
flowerin^or  "many  years  together,  and  grows 
meanwhile  larger  and  larger  in  bulk,  its  trunk 
increasing  in  girth,  and  becoming  buttressed  at 
the  base,  so  as  to  support  the  large  head  of 
branches  and  the  dense  mass  of  foliage.  For 
the  boughs  are  so  arranged  that  a  great  crown 


SOME    PLANT    BIOGKAPHIES.  207 

of  leaves  is  exposed  in  summer  to  the  sun  and 
air  at  the  outer  circumference  of  the  dome- 
shaped  mass ;  and  in  this  way  every  leaf  gets 
its  fair  share  of  light  and  carbon,  and  interferes 
as  little  as  possible  with  the  work  of  its  neigh- 
bours. Old  beeches  will  grow  to  more  than 
100  feet  in  height,  and  live  for  probably  three  or 
four  centuries.  At  last,  however,  their  proto- 
plasm grows  old  and  seems  to  get  enfeebled ; 
the  trunk  decays,  and  the  entire  tree  falls  first 
into  dotage,  then  dies  by  slow  degrees  of  pure 
senility. 

The  common  vetch  is  another  familiar  plant 
whose  life -history  introduces  to  us  some  totally 
different  yet  interesting  features.  It  belongs  to 
the  wide-spread  family  of  the  peaflowers,  to 
which  I  have  already  more  than  once  alluded, 
and  it  takes  its  origin  from  a  comparatively  large 
and  rich  round  seed,  not  unlike  a  pea,  whose 
cotyledons  are  well  stored  with  supplies  of  starch 
and  other  food- stuffs.  It  sends  up  at  first  a 
short  spreading  stem,  which  twines  or  trails 
over  surrounding  plants,  developing  as  it  goes 
very  curious  leaves  of  a  compound  character. 
Each  leaf  consists  of  five  or  six  pairs  of  leaflets, 
placed  opposite  one  another  on  the  common 
stalk  in  the  feather- veined  fashion.  But  the 
four  or  five  leaflets  at  the  end  of  each  leaf- 
stalk do  not  develop  any  flat  blade  at  all,  and 
are  quite  unleaflike  in  appearance :  they  are 
transformed,  indeed,  into  long  thin  tendrils, 
which  catch  hold  of  neighbouring  branches  or 
stems  of  grasses,  twine  spirally  round  them,  and 
so  enable  the  vetch  to  climb  up  bodily  in  spite 


208       THE  STORY  OP  THE  PLANTS. 

of  its  weak  stem,  and  raise  its  leaves  and  flowers 
to  the  air  and  the  sunlight. 

At  the  base  of  every  leaf,  again,  you  will  find, 
if  you  look,  two  arrow-shaped  appendages,  which 
block  the  way  up  the  stem  towards  the  deve- 
loping flowers  for  useless  creeping  insects  such 
as  steal  the  honey  without  assisting  fertilisation. 
On  each  appendage  is  a  curious  black  spot,  the 
use  or  function  of  which  is  not  apparent  while 
the  blossoms  are  in  the  bud.  But  after  a  few 
weeks'  growth,  the  vetch  begins  to  produce 
solitary  flowers  in  the  angle  of  each  upper 
leaf ;  flowers  of  the  usual  pea-blossom  type, 
but  pink  or  reddish  purple,  and  handsome  or 
attractive.  These  flowers  contain  abundant 
honey  to  allure  the  proper  fertilising  insects. 
Just  as  they  open,  however,  the  black  spot  on 
the  arrow-headed  appendages  of  the  lower 
leaves,  in  whose  angles  there  are  no  flowers, 
begins  also  to  secrete  a  little  drop  of  honey. 

What  is  the  use  of  this  device  ?  Well,  if 
you  watch  the  vetch  carefully,  you  will  soon 
see  that  ants,  enticed  by  the  smell  of  honey  in 
the  opening  flowers,  crawl  up  the  stem  in  hopes 
of  stealing  it.  But  ants,  as  we  know,  are 
thieves,  not  fertilisers.  As  soon  as  they  reach 
the  first  black  spot,  they  stop  and  lick  up  the 
honey  secreted  by  the  gland,  and  then  try  to 
pass  on  to  the  next  appendage  above  it.  But 
the  arrow-shaped  barbs,  turned  back  against  the 
stem,  block  their  further  progress ;  and  even  if 
they  manage  to  squeeze  themselves  through  with 
an  effort,  they  are  met  just  above  by  another 
honey-gland  and  another  barrier  in  the  shape  of 


SOME    PLANT    BIOGRAPHIES  209 

a  second  arrow-shaped  appendage.  No  ant  ever 
gets  beyond  the  third  or  fourth  barricade ;  the 
device  is  efficient :  the  vetch  thus  offers  black- 
mail to  creeping  thieves  in  the  shape  of  stem- 
honey,  in  order  to  guard  from  their  depredations 
the  far  more  valuable  and  useful  honey  in  the 
flowers,  which  is  intended  to  attract  the  fertilising 
insects. 

When  the  purple  flowers  have  in  due  time 
been  fertilised,  they  produce  long  narrow  pods, 
each  containing  about  a  dozen  round  pea-like 
seeds.  As  the  pods  ripen,  the  plant  shrivels  up, 
and  usually  dies  away,  leaving  only  the  ripe 
seeds  to  represent  its  kind  through  the  winter. 
But  sometimes,  in  damp  and  luxuriant  autumns, 
the  stem  struggles  through  the  winter  to  a  second 
season,  and  flowers  again  in  the  succeeding 
summer.  We  express  this  fact  as  a  rule  by 
saying  that  the  vetch  is  usually  an  annual,  but 
occasionally  a  biennial. 

With  most  annuals,  such  as   wheat  or  sun- 
flower, thg^yvhqle  strength  d:  the  plant.j^used^ 
up  in  tSepfod  ilc  Lion  of  seed  T  ana  as Tsoonas 
the   seed  is  set,   the    plant    dies    immediately. 
Where   annuals  have    the    sexes    on    separate 
plants,    however,   thejm£j£_4jlan^ 
as    they    have    sheT^TheirpolIen^ 
being  thus  complete ;  while  the^females  live^og 
till  their  seed  has  ripened. 

Common  coltsfoot  is  another  well-known  plant 
whose  life-history  shows  some  points  of  great 
interest.  It  grows  in  the  first  instance  from 
a  feathery  fruit,  one- seeded  and  seed- like,  which 
is  carried  by  the  wind,  often  from  a  greafe 
14 


SlO  T?ltE    StfOKY   OF   tfHE    PLANTS* 

distance.  These  flying  fruits  alight  at  last 
upon  some  patch  of  bare  or  newly-turned  soil, 
such  as  the  bank  of  a  stream  where  there  has 
been  lately  a  landslip,  or  the  side  of  a  railway 
cutting.  These  bare  situations  alone  suit  the 
habits  of  the  baby  coltsfoot ;  if  the  fruit  happens 
to  settle  on  a  light  soil,  already  thickly  covered 
with  luxuriant  vegetation,  it  cannot  compete 
against  the  established  possessors.  But  the 
winged  fruits,  being  dispersed  on  every  side, 
enable  many  young  plants  to  start  well  in  life 
on  the  poor  stiff  clays  which  best  suit  the  con- 
stitution of  this  riverside  weed.  The  seedling 
grows  fast  in  such  circumstances,  and  soon  pro- 
duces large  angular  leaves,  very  broad  and  thick, 
which  in  the  adult  plant  have  often  a  diameter 
of  five  or  six  inches.  They  are  green  above, 
where  they  catch  the  sunlight  and  devour 
carbonic  acid  ;  but  underneath  they  are  covered 
with  a  thick  white  wool,  which  is  there  for  a 
curious  and  interesting  purpose.  The  damp 
clay  valleys  and  river  glens  where  coltsfoot 
lives  by  choice  are  filled  till  noon  every  day 
with  mist  and  vapour ;  and  heavy  dew  is 
deposited  there  every  night  through  the  summer 
season.  Now,  if  this  dew  were  allowed  to  clog 
the  evaporation  pores  or  stomata  on  the  leaves  of 
•coltsfoot,  the  plant  would  not  be  able  to  raise: 
water  or  proceed  with  its  work  except  for  per- 
haps a  few  hours  daily.  To  prevent  this  mis- 
•  fortune,  the  under  side  of  the  leaves  is  thickly 
covered  with  a  white  coat  of  wool,  on  which  no- 
dew  forms,  and  off  which  water  rolls  in  little- 
-round  drops,  as  you  have  seen  it  roll  off  a  serge5 


PLAN*  BIOGRAPHIES.  211 

table-cloth.  By  this  ingenious  device  the  colts- 
foot manages  to  keep  its  evaporation  pores  dry 
and  open,  in  spite  of  its  damp  and  moisture- 
laden  situation.  One  may  say,  indeed,  that 
every  point  in  the  structure  of  every  plant  has 
thus  some  special  purpose;  indeed,  one  large 
object  of  the  study  of  plants  is  to  enable  us  to 
understand  and  explain  such  hidden  purposes  in 
the  economy  of  nature. 

During  its  early  life,  once  more,  the  young 
plant  of  coltsfoot  is  constantly  engaged,  like  the 
whitlow-grass  and  the  agave,  in  laying  hy 
material  fqr.  its  future  flowering  "season,  jiu't 
it  does  not  lay  by,  as  they  do,  in  its  expanded 
le  aves  or  other  portions  of  its  body  visible  above 
g  round  ;  instead  of  that,  it  puts  forth  a  creeping 
underground  stem  or  root-stock,  which  pushes 
its  way  sideways  through  the  tough  clay  soil, 
often  for  several  feet,  and  sends  up  at  intervals 
groups  of  large  roundish  leaves,  such  as  I  have 
already  described,  to  work  above  ground  for  it. 
You  might  easily  take  each  such  group  for  a 
separate  plant,  unless  you  dug  up  the  root- stock 
and  saw  that  they  were  really  the  scattered 
foliage  of  one  subterranean  stem,  which  grows 
horizontally  instead  of  upward.  During  the 
summer  the  coltsfoot  lays  by  in  this  buried 
root-stock  quantities  of  rich  material  for  next 
year's  leaves  and  for  its  future  flowers.  In 
winter  the  leaves  die  down,  and  you  see  not 
a  trace  of  the  plant  above  ground.  But  in  very 
early  spring,  as  soon  as  the  soil  thaws,  certain 
special  buds  begin  to  sprout  on  the  underground 
stem,  and  send  up  tall  naked  scapes  or  flower- 


^12        THfc  STORY  OF  THE  PLANTS; 

stems,  usually  growing  in  tufts  together,  and 
each  crowned  by  a  single  large  fluffy  yellow 
flower-head.  These  stems  are  covered  below 
by  short  purplish  scales ;  and  their  purple 
colouring  matter  enables  them  to  catch  and 
utilise  to  the  utmost  the  scanty  sunshine  that 
falls  upon  the  plant  in  chilly  March  weather. 
For  this  particular  colouring  matter  has  the 
special  property  of  converting  the  ehergy  in. 
rays  of  light  into  heat  for  warming  the  plant. 
The  scape  is  also  wrapped  up  in  a  sort  of 
cottony  Wool,  which  helps  to  keep  it  warm  ;  and 
the  unopened  flower-head  turns  downward  at 
first  for  still  further  safety  against  chill  or 
injury.  These  various  devices  enable  the  colts- 
foot to  blossom  earlier  in  the  season  than  almost 
any  other  insect-fertilised  flower,  and  so  to 
monopolise  the  time  and  attention  of  the  first 
flower-haunting  March  insects. 

Coltsfoot  is  a  composite  by  family ;  so  its 
flowers  are  collected  together  into  a  head,  after 
the  ancestral  fashion,  and  enclosed  by  an  in- 
volucre which  closely  resembles  a  calyx.  But 
the  type  of  flower-head  differs  somewhat  from 
that  in  any  of  the  composite  plants  I  have 
hitherto  described  for  you,  because  its  outer 
florets  are  not  flat  and  ray-shaped,  but  strap-like 
or  needle-shaped.  The  inner  florets,  however, 
are  bell-shaped,  and  much  like  those  of  the 
common  daisy.  The  naked  scapes,  each  re- 
sembling to  the  eye  a  shoot  of  asparagus,  and 
each  crowned  by  a  single  fluffy  yellow  flower-head, 
are  familiar  objects  on  banks  or  railway  cuttings 
in  the  first  days  of  spring ;  I  have  known  them 


SOME    PLANT    BIOGKAPHIES.  213 

open  as  early  as  the  12th  of  January,  in  sunny 
weather.  But  they  grow  entirely  without 
leaves,  and  are  produced  at  the  expense "of ~tKe 
material  laid  up  in  the  underground  stem  by 
last  season's  foliage.  They  blossom,  are/ 
fertilised,  set  their  seeds,  turn  into  heads  of 
white  feathery  down,  and  produce  ripe  fruits 
which  blow  away  and  get  dispersed,  all  before 
the  leaves  begin  to  appear  at  all  above  the^soiT 
Thus  you  never  can  see  the  foliage  and  flowers 
together  ;  it  is  only  by  close  observation  that 
you  can  discover  for  yourself  the  connection 
between  the  heads  of  yellow  flowers  which  come 
up  in  early  spring,  and  the  groups  of  large 
angular  woolly  leaves  which  follow  them  in  the 
same  spots  much  later  in  the  season. 

The  life-history  of  the  coltsfoot  introduces  us 
also  to  another  conception  which  we  must  clearly 
understand  if  we  wish  to  know  anything  about 
many  plant  biographies.  I  have  said  already 
that  parts  of  one  and  the  same  coltsfoot  plant 
might  easily  be  mistaken  for  separate  indi- 
viduals ;  and,  indeed,  if  the  stem  gets  severed, 
particular  groups  of  leaves  may  live  on  as  such, 
in  two  or  more  distinct  portions.  This  leads  us 
on  to  the  consideration  of  a  great  group  of 
plants  like  the  common  wild  strawberry,  in 
which  a  regular  system  of  subdivision  exists, 
and  in  which  new  plants  are  habitually  pro- 
duced by  offsets  or  runners,  as  well  as  by  seed- 
lings. Such  a  method  of  increase  is  to  some 
extent  a  survival  into  higher  types  of  the  primi- 
tive, mode  of  reproduction  by  subdivision. 

A  strawberry  plant  grows' in  the  first  instance 


214       THE  STORY  OF  THE  PLANTS. 

from  a  seed,  which  was  embedded  in  a  carpel  or 
seed-like  fruitlet  on  the  ripe  red  swollen  recep- 
tacle which  we  commonly  call  *§T?frawBerry. 
This  seed  germinates,  and  produces  a  seedling, 
which  puts  forth  small  green  leaves,  divided 
into  three  leaflets  each  at  the  end  of  a  long  and 
slender  leaf -stalk.  As  it  grows  older,  however, 
besides  its  own  tufted  perennial  stem  or  stock, 
it  sends  out  on  every  side  long  branches  or 
runners,  which  are  in  fact  horizontal  or  creeping 
stems  in  search  of  new  rooting  places.  These 
stems  run  along  the  ground  for  some  inches, 
and  then  root  afresh.  At  each  such  rooting- 
point,  the  plant  sends  up  a  fresh  bunch  of  leaves, 
which  gradually  grows  into  a  distinct  colony,  by 
the  decay  of  the  intermediate  portion  or  runner. 
Again,  this  new  plant  itself  in  turn  sends  forth 
runners  in  every  direction  all  round  it ;  so  that 
often  the  ground  is  covered  for  yards  by  a  net- 
work of  strawberry  plants,  all  ultimately  derived 
from  a  single  seedling.  Theoretically,  we  must 
regard  them  all  as  severed  parts  of  one  and  the 
same  plant,  accidentally  divided  from  the  main 
stem,  since  only  the  union  of  two  different 
parents  can  give  us  a  totally  distinct  individual. 
But  practically  they  are  separate  and  indepen- 
dent plants,  competing  with  one  another  thence- 
forth for  food,  soil,  and  sunshine. 

A  great  many  plants  are  habitually  propagated 
in  such  indirect  ways,  as  well  as  by  the  normal 
method  of  flowering  and  seeding.  Indeed,  it  is 
difficult  to  separate  the  two  processes  of  mere 
growth,  as  shown  in  budding  or  branching,  and 
reproduction  by  subdivision,  as  shown  in  the 


SOME    PLANT   BIOGKAPHIES.  215 

springing  of  saplings  from  the  roots  or  stem, 
the  production  of  runners,  the  division  of  bulbs, 
and  the  rooting  of  suckers.  I  will  therefore  give 
here  a  few  select  instances  of  these  frequent 
incidents  in  the  life-history  of  various  species. 

The  tiger-lilies  of  our  gardens  produce  little 
dark  buds,  often  called  bulbils,  in  the  angles  of 
their  foliage  leaves.  These  buds  at  last  fall  off 
and  root  themselves  in  the  soil,  forming  to  all 
appearance  independent  plants.  Much  the 
same  thing  happens  with  many  English  wild- 
flowers.  For  example,  in  the  plant  known  'as 
coral-root  (allied  to  the  cuckoo-flower)  little  bud- 
bulbs  are  formed  in  the  angles  of  the  leaves, 
which  drop  on  the  damp  soil  of  the  woods 
where  the  plant  grows,  and  there  develop  into 
new  individuals.  In  this  last-named  case  the 
plant  seldom  sets  its  fruit  at  all,  the  reproduction 
being  almost  entirely  carried  on  by  means  of  the 
bulbils.  Such  instances  suggest  to  us  the 
pregnant  idea  that  a  seed  is  nothing  more  than 
a  bud  or  young  shoot,  to  whose  making  two 
separate  parents  have  contributed.  There  is,  in 
short,  no  essential  difference  between  the  two 
processes  of  growth  and  reproduction. 

Again,  in  the  common  lesser  celandine  the 
root-stock  emits  a  large  number  of  tiny  pill-like 
tubers,  which  grow  and  lay  by  rich  material 
underground  (derived  from  the  leaves)  during 
the  summer  season.  In  the  succeeding  spring, 
however,  each  of  these  tubers  develops  again 
into  a  separate  plant,  in  a  way  with  which 
the  familiar  instance  of  the  potato  has  made  us 
familiar,  In  the  crocus,  once  more,  and  many 


216        THE  STORY  OF  THE  PLANTS. 

other  bulbous  plants,  several  small  bulbs  are  pro- 
duced each  year  by  the  side  of  the  large  one,  and 
these  smaller  bulbs  are  of  course,  strictly  speak- 
ing, mere  branches  of  the  original  crocus-stem. 
But  they  grow  separate  at  last,  by  the  decay  or 
death  of  the  central  bulb,  and  themselves  in 
turn  produce  at  their  side  yet  other  bulbs,  which 
become  the  centres  of  still  newer  families.  We 
may  parallel  these  cases  with  those  of  trees  whose 
boughs  bend  down  and  root  in  the  ground  so  as 
to  become  in  time  independent  individuals  ;  or 
with  runners  like  those  of  the  strawberry  and 
the  creeping  buttercup,  which  root  and  grow 
afresh  into  separate  plantlets. 

Sometimes  still  more  curious  things  happen 
to  plants  in  the  way  of  reproduction  by  sub- 
division. There  is  an  English  pondweed,  for 
example,  which  grows  in  shallow  pools  liable  to 
be  frozen  over  in  severe  winters.  As  cold 
weather  approaches,  the  top  of  the  growing 
shoots  in  this  particular  pondweed  break  off 
of  themselves,  much  as  leaves  do  at  falling  time. 
But  they  break  off  with  all  their  living  material 
still  preserved  within  them  undisturbed  ;  and 
they  then  sink  and  retire  to  the  unfrozen 
depths  of  the  pond,  where  they  remain  unhurt 
till  spring  comes  round  again.  This  is  just 
what  the  frogs  and  newts  and  other  animal 
inhabitants  of  the  pond  do  at  the  same  time,  to 
prevent  getting  frozen.  Next  year  the  severed 
tops  send  out  roots  in  the  soft  mud  of  the  bottom, 
and  grow  up  afresh  into  new  green  pondweeds. 

It  is  therefore  impossible  to  make  any  broad 
line  of  distinction  in  this  way  between  what  may 


SOME    PLANT    BIOGRAPHIES.  217 

be  considered  as  modes  of  individual  persistence  in 
the  self-same  plants,  and  what  may  be  regarded 
as  modes  of  reproduction  by  subdivision.  Some 
plants,  like  couch-grass  and  elm,  are  almost 
always  surrounded  by  young  shoots  which  may 
ultimately  become  to  all  intents  and  purposes 
independent  individuals ;  while  others,  like 
corn-poppy  or  Scotch  fir,  never  produce  any  off- 
sets or  suckers.  In  the  meadow  orchids  each 
plant  produces  every  summer  a  second  tuber  by 
the  side  of  the  old  one  ;  and  from  the  top  of 
this  tuber  the  next  year's  stem  arises  in  due 
time  with  its  spike  of  flowers.  Here  we  may 
fairly  regard  the  tuber  as  a  simple  means  of 
persistence  in  the  plant  itself ;  there  is  nothing 
we  could  possibly  call  reproduction.  But  in 
many  lilies  the  older  bulbs  produce  numerous 
small  branch  bulbs  at  their  sides ;  and  these 
younger  bulbs  may  become  practically  indepen- 
dent, each  of  them  sending  up  in  the  course  of 
time  its  own  stem  and  its  own  spike  of 
flowers. 

Even  when  the  main  trunk  of  a  tree  is  dead, 
through  sheer  old  age,  it  often  happens,  as  in 
the  elm  and  birch,  that  the  roots  send  up  fresh 
young  shoots,  which  may  grow  again,  and 
prolong  the  life  of  the  plant  indefinitely.  In 
stone-crops  and  other  succulent  herbs,  which 
grow  in  very  dry  and  desert  situations,  the 
merest  fragment  of  a  stem,  dropped  on  moist 
soil,  will  send  out  roots  and  grow  afresh 
into  a  new  individual.  Cactuses  and  other 
desert  plants  have  often  to  resist  immense 
drought,  and  therefore  possess  extraordinary 


218        THE  STORY  OF  THE  PLANTS. 

vitality  in  this  way.  They  will  grow  again  from 
the  merest  cut  end  under  favourable  conditions. 
These  few  short  hints  as  to  the  life-history  of 
various  plants  in  different  circumstances  will 
serve  to  show  you  how  vast  is  their  variety. 
Every  plant,  indeed,  has  endless  ways  and 
tricks  of  its  own ;  and  every  point  in  its 
structure,  however  unobtrusive,  has  some 
purpose  to  serve  in  its  domestic  economy.  Thus 
the  ivy-leaved  toad-flax,  which  grows  on  dry 
walls,  has  straight  flower-stalks,  which  become 
bent  or  curved  when  the  flowering  is  over. 
Why  is  this  ?  Well,  the  plant  has  acquired  the 
habit  of  bending  round  its  flower-stalk  after  the 
blossoming  season,  because  it  cannot  sow  its 
seeds  on  the  bare  stone,  so  it  hunts  about 
diligently  for  a  crevice  among  the  mortar  into 
which  it  proceeds  to  insert  its  capsule,  so  that 
the  seedlings  may  start  fair  in  a  fit  and  proper 
place  for  their  due  germination.  So,  too,  the 
subterranean  clover,  growing  on  close-cropped 
hillocks  much  nibbled  over  by  sheep,  where  its 
pods  of  rich  seeds  would  be  certainly  devoured 
if  exposed  on  a  long  stalk  like  that  of  other 
clovers,  has  developed  a  few  abortive  corkscrew- 
like  blossoms  in  the  centre  of  its  flower-head, 
by  whose  aid  the  whole  group  of  pods  burrows 
its  wayj  spirally  into  the  soil  beneath ;  so  that 
the  plant  thus  at  once  escapes  its  herbivorous 
enemies,  and  sows  its  own  seed  for  itself  auto- 
matically. It  would  be  impossible  in  our  space 
to  do  more  than  thus  briefly  indicate  by  two  or 
three  examples  the  immense  number  and  variety 
of  these  special  adaptations.  Every  plant  has 


SOME    PLANT    BIOGRAPHIES.  219 

hundreds  of  them.  There  is  not  a  tiny  hair  on 
the  surface  of  a  flower,  not  a  spot  or  a  streak  in 
the  blade  of  a  leaf,  not  a  pit  or  depression  on  the 
skin  of  a  seed,  that  has  not  its  function.  And 
close  study  of  nature  rewards  us  most  of  all 
for  our  trouble  in  this,  that  it  reveals  to  us 
every  day  some  delightful  surprise,  forces  on 
our  attention  some  hitherto  unsuspected  but 
romantic  relation  of  structure  and  purpose. 

I  will  mention  but  one  more  case  as  a  typical 
example.  There  exists  as  a  rule  a  definite 
relation  between  the  shape  and  arrangement  of 
the  leaves  in  plants,  and  the  shape  and  arrange- 
ment of  the  roots  and  rootlets,  with  regard  to 
water-supply.  Each  plant,  in  point  of  fact,  is 
like  the  roof  of  a  house  as  respects  the  amount 
of  rain  which  it  catches  arid  drains  away ;  and 
it  is  important  for  each  that  it  should  utilise  to 
the  utmost  its  own  particular  supply  of  drainage 
or  rain  water.  Hence  you  will  find  that  some 
plants,  like  the  dock,  have  large  channeled 
leaves,  with  a  leaf -stalk  traversed  by  a  depres- 
sion like  a  drainage  runnel :  plants  of  this  type 
carry  off  all  the  water  that  falls  upon  them 
towards  the  centre,  inwards.  But  such  plants 
have  always  also  a  descending  tap-root,  which 
instantly  catches  and  drinks  up  the  water  poured 
by  the  drainage  system  of  the  leaves  towards 
the  middle  of  the  plant.  In  other  plants,  again, 
however,  with  round  leaf-stalks  and  outward 
pointed  leaves,  the  water  that  falls  upon  the 
foliage  drains  outward  towards  the  circum- 
ference ;  and  in  all  such  plants  the  roots,  in- 
stead of  descending  straight  down,  are  spread- 


220        THE  STORY  OF  THE  PLANTS. 

ing  and  diffused,  so  as  to  go  outward  towards 
the  point  where  the  water  drips  on  them. 
Moreover,  in  this  latter  case  it  is  found,  on 
digging  up  the  plant  carefully,  that  the  ab- 
sorbent tips  of  the  rootlets  are  clustered 
thickest  about  the  exact  spots  where  the  leaves 
habitually  drop  the  water  down  upon  them. 
Every  plant  is  thus  to  some  extent  a  catchment- 
basin  which  utilises  its  own  rainfall :  it  collects 
rain  for  itself,  and  conducts  it  by  a  definite 
system  of  pipes  and  channels  to  the  precise 
spots  in  the  soil  where  it  can  best  be  sucked  up 
for  the  plant's  own  purposes. 

On  the  other  hand,  while  every  part  of  every 
plant  is  thus  minutely  arranged  for  the  common 
advantage,  every  species  of  plant  and  animal 
fights  only  for  its  own  hand  against  all  comers. 
Nature  is  therefore  one  vast  theatre  of  plot  and 
counterplot.  The  parasites  prey  on  the  vegeta- 
tive kinds  ;  the  vegetative  kinds  respond  in  turn 
by  developing  checks  to  counteract  the  parasites. 
The  squirrels  produce  sharper  and  ever  sharper 
teeth  to  gnaw  through  the  nutshells ;  the  nut- 
trees  retaliate  by  producing  for  their  part  thicker 
and  ever  thicker  shells  to  baffle  the  squirrels. 
And  this  play  and  by-play  goes  on  unceasingly 
from  generation  to  generation  ;  because  only  the 
cleverest  squirrels  can  ever  get  enough  nuts  to 
live  upon ;  and  only  the  hardest-shelled  and 
bitterest-rinded  nuts  can  escape  the  continual 
assaults  of  the  squirrels.  In  order,  therefore, 
really  to  understand  the  structure  and  life  of 
any  one  species,  we  should  have  to  know  in  the 
minutest  detail  all  about  its  native  conditions, 


THE    PAST    HISTORY    OF    PLANTS  221 

its  soil,  its  surroundings,  its  allies,  its  hired 
friends,  its  blackmailing  foes,  its  exterminating 
enemies.  Such  exhaustive  knowledge  of  the 
tiniest  weed  is  clearly  impossible ;  but,  even  the 
little  episodes  we  can  pick  out  piecemeal  are  full 
of  romance,  of  charm,  and  of  novelty. 


CHAPTEE  XIV. 

THE    PAST    HISTORY   OF   PLANTS. 

I  PROMISED  some  time  since  to  return  in  due 
season  to  the  question  why  plants,  as  a  rule, 
exhibit  distinct  kinds  or  species,  instead  of 
merging  gradually  one  into  another  by  imper- 
ceptible degrees.  This  problem  is  generally 
known  as  the  problem  of  the  origin  of  species. 
You  might  perhaps  expect  (since  plants  have 
grown  and  developed,  as  we  have  seen,  one  out 
of  the  other)  that  they  would  consist  at  present  of 
an  unbroken  series,  each  melting  into  each,  from 
the  highest  to  the  lowest.  This,  however,  is 
not  really  the  case ;  they  form  on  the  contrary 
groups  of  distinct  kinds  :  and  the  reason  is,  that 
natural  selection  acts  on  the  whole  in  the  oppo- 
site direction.  It  tends  to  make  plants  group 
themselves  into  definite  bodies  or  species,  all 
alike  within  the  body,  and  well  marked  off  from 
all  others  outside  it. 

Here  is  the  way  this  arrangement  comeb 
about.  As  situations  and  circumstances  vary, 
a  form  is  at  last  arrived  at  in  each  situation 
which  approximately  fits  the  particular  circum- 

^"       '"  ^ 


222       THE  STOKY  OP  THE  PLANTS. 

stances.  This  form  may  perhaps  vary  again  in 
other  situations,  and  give  rise  to  individuals 
better  adapted  to  the  second  set  of  circum- 
stances. But  just  in  proportion  as  such  in- 
dividuals surpass  in  adaptation  one  another  will 
they  live  down  the  less  adapted.  Hence,  the 
intermediate  forms  will  tend  to  perish,  and  the 
world  to  be  filled  in  the  end  with  groups  of 
plants,  each  distinct  from  others,  and  each 
relatively  fixed  and  similar  within  its  own 
limits. 

At  all  times,  and  in  all  places,  this  process  of 
variation  and  adaptation  is  continually  going 
on ;  new  kinds  are  being  formed,  and  inter- 
mediates are  dying  out  between  them.  For  the 
intermediates  are  necessarily  less  adapted  than 
the  older  form  to  the  old  conditions,  and  than 
the  newer  form  to  the  new  ones. 

Moreover,  when  any  great  point  of  advantage 
is  once  gained  by  a  kind,  it  tends  to  go  on  and 
be  preserved,  while  variations  in  other  parts 
continue  uninterrupted.  Thus,  the  first  com- 
posite plant  (to  take  a  concrete  example)  gained 
by  the  massing  of  its  flowers  into  a  compact 
head  :  and  it  then  became  a  starting-point  for 
fresh  developments,  each  of  which  maintained 
the  massed  flower-head,  with  its  ring  of  united 
stamens,  while  adding  to  the  type  some  fresh 
point  of  its  own,  which  specially  adapted  it  to  a 
particular  situation.  So,  too,  the  first  peaflower 
gained  by  the  peculiar  form  of  its  oddly-shaped 
corolla,  and  therefore  became  the  ancestor  of 
many  separate  kinds,  each  of  which  retains  the 
general  pea-like  type  of  blossom,  while  differing 


THE   PAST   HlSTOIiY    OF    PLANTS.  223 

in  other  respects  as  widely  from  its  neighbours 
as  gorse  and  clover,  peas  and  laburnum,  broom 
and  vetches,  scarlet-runners  and  lupines.  A 
group  of  kinds,  so  derived  from  a  common  pro* 
genitor,  but  preserving  throughout  one  or  more 
of  that  progenitor's  peculiarities  while  differing 
much  in  other  respects  among  themselves,  is 
called  a  family.  Thus  we  speak  of  the  family 
of  the  peaflowers,  the  family  of  the  roses,  the 
family  of  the  lilies,  the  family  of  the  orchids. 
Each  family  may  include  several  minor  groups, 
Jmown  as  genera  (in  the  singular,  a  genus) ;  and  • 
each  such  genus  may  further  include  several 
distinct  kinds  or  species. 

For  example,  all  the  peaflower  family  are  dis- 
tinguished by  their  possession  of  a  peculiar 
blossom  whose  corolla  consists  of  a  standard,  a 
keel,  and  two  wings,  like  sweet-pea  or  broom. 
This  family  contains  several  genera,  one  of 
which  is  that  of  the  clovers,  including  certain 
peaflowers  which  have  learned  to  mass  their 
blossoms  into  a  roundish  head,  and  have  trefoil 
leaves,  and  very  few  seeds  in  the  short  seed-pod. 
The  clovers,  again,  are  subdivided  into  species  or 
kinds,  such  as  purple  clover,  Dutch  clover,  hop 
•clover,  and  hare's  foot  clover ;  in  Britain  alone, 
we  have  twenty-one  such  distinct  species  or 
kinds  of  clover.  You  will  see  at  once  that  this 
method  of  grouping  by  ancestral  forms  enables 
us  largely  to  reconstruct  the  history  of  each 
particular  plant  or  animal. 

Why  don't  these  kinds  cross  freely  with  one  \ 
•another,    and   so    produce    an    endless    set    of 
puzzling  hybrids  ?     Well,  they  do  occasionally  ;  J 


224       THE  STORY  OP  THE  PLANTS. 

and  such  mongrel  forms  often  show  us  every 
possible  variation  between  the  two  parents. 
But  this  can  only  happen  when  the  parent  stocks 
are  very  close  to  one  another;  and  even  then, 
the  hybrids  tend  to  die  out  rapidly.  Why? 
Because  each  of  the  parents  is  better  adapted  to 
a  particular  situation  ;  the  hybrid  usually  falls 
between  two  stools,  and  gets  killed  down  accord- 
ingly. It  cannot  stand  the  competition  of  the 
true  species.  New  kinds,  however,  may  some- 
times take  their  rise  from  chance  hybrids,, 
which  happen  to  possess  some  combination  of 
advantages. 

Thus  plants  in  the  mass,  as  we  see  them 
around  us  at  the  present  day,  are  divisible  into 
several  well-marked  groups,  some  of  which  are 
now  dominant  or  leading  orders,  while  others 
are  hardly  more  than  mere  belated  stragglers  or 
loitering  representatives  of  types  once  common, 
but  now  outstripped  in  the  race  by  younger 
competitors.  I  cannot  close  without  briefly 
describing  to  you  the  main  divisions  of  such 
orders  or  groups,  as  now  accepted  by  modern 
botanists. 

The  widest  distinction  of  all  between  plants  is 
that  which  marks  off  the  simpler  and  earlier 
forms,  which  are  wholly  composed  of  cells,  from 
the  higher  and  stem-forming  types,  which  are 
also  provided  with  systems  of  vessels  and  woody 
tissue.  The  first  class  is  known  as  CELLULAB 
I  PLANTS  ;  the  second  class  as  VASCULAR  PLANTS. 
These  are  the  greatest  and  most  general 
divisions. 


THE    PAST    HISTORY   OP   PLANTS.  225 

The  CELLULAR  PLANTS  comprise  many  sorts, 
from  the  simple  one-celled  types  which  float 
freely  in  water,  up  to  the  relatively  high  and 
complex  seaweeds,  which  produce  large  fleshy 
fronds,  and  often  display  a  considerable  division 
of  labour  between  their  various  parts  and  organs. 
Still,  as  most  of  them  live  in  water,  either  fresh 
or  salt,  and  wave  freely  about  in  the  liquid  that 
surrounds  them,  they  have  no  need  of  an  elabo- 
rate system  of  conducting  vessels,  because  every 
part  can  drink  in  water  and  dissolved  food- salts 
from  the  neighbouring  pond,  sea,  or  river.  Still 
less  have  they  any  necessity  for  a  woody  stem, 
which  would  only  be  a  disadvantage  to  them  in 
stormy  weather.  Hence  most  of  the  cellular 
plants  (with  certain  exceptions  to  be  noted  here- 
after) are  water- weeds ;  while  most  of  the 
vascular  plants  (with  other  exceptions  to  be 
similarly  treated)  are  land  plants.  In  particular 
trees  and  shrubs,  the  highest  forms  of  plant  life, 
are  invariably  terrestrial. 

Various  successive  stages  of  these  cellular 
plants  may  be  briefly  described  in  rough  out- 
line. First  of  all  we  get  the  simple  one-celled 
plant,  the  lowest  type  of  all,  consisting  of  a 
single  mass  of  protoplasm,  generally  with 
chlorophyll,  surrounded  by  a  cell- wall.  Next 
above  these  come  the  hair-like  water-weeds, 
which  consist  of  rows  of  such  simple  cells, 
placed  end  to  end  in  single  file,  one  in  front  of 
another,  like  pearls  in  a  necklace.  These  kinds 
are  many-celled,  but  each  cell  is  here  in  contact 
with  two  others  only,  one  below,  and  one  above 
it.  Thirdly,  we  get  the  flat  leaf-like  water- 


226  THE    STOKY   OF   THE   PLANTS. 

weeds,  which  have  thin  green  fronds,  composed 
of  a  single  broad  sheet  of  cells,  not  a  hair-like 
row ;  each  cell  has  here  many  cells  around  it, 
but  all  lie  in  one  plane ;  the  sheet  is  only  one 
cell  thick  ;  it  does  not  spread  abroad  in  more 
than  two  directions.  Lastly,  we  get  the  ordi- 
nary thick-fronded  seaweed,  in  which  sheets  of 
cells,  many  layers  deep,  grow  in  divided  masses 
on  rope-like  bases,  and  closely  resemble  to  the 
eye  true  vascular  plants  with  stems,  leaves,  and 
branches. 

Most  of  these  cellular  plants,  when  they 
possess  green  chlorophyll,  are  known  as  algce. 

There  are  several  low  forms  of  plants,  how- 
ever, which  do  not  possess  chlorophyll,  but  live 
at  the  expense  of  other  plants,  exactly  as 
animals  do.  These  are  generally  known  in  the 
lump  as  fungi.  Many  of  them  are  terrestrial. 
The  distinction,  however,  is  not  a  genealogical 
one.  Cellular  plants  of  various  grades  have 
often  taken,  time  after  time,  to  this  lower 
parasitic  or  carrion-eating  habit ;  and  though 
they  therefore  resemble  one  another  externally 
in  their  absence  of  green  colour,  in  their  usual 
whiteness  and  fleshiness,  and  in  their  mush- 
room-like substance,  they  do  not  really  form  a 
natural  class ;  their  resemblance  is  due  to  their 
habits  only.  In  short,  we  call  any  cellular  plant 
a  fungus,  if  instead  of  supporting  itself  by  green 
cells,  it  has  adopted  the  trick  of  living  on 
organised  material  already  laid  up  by  other 
plants  or  animals. 

Among  these  fungus-like  plants,  again,  some 
of  the  simplest  and  lowest  are  the  celebrated 


THE    PAST    HISTOBY   OF   PLANTS.  227 

bacteria,  which  are  one-celled  organisms,  living 
in  stagnant  or  putrid  fluids,  and  also  in  the 
bodies  and  blood  of  diseased  animals.  They 
answer  among  fungi  to  the  one-celled  alga. 
Many  of  them  cause  infectious  diseases ;  such 
are  the  bacilli  of  diphtheria,  typhus,  cholera, 
consumption,  small-pox,  and  influenza.  Sur- 
rounded by  a  suitable  nutritious  fluid,  these  tiny 
parasitic  plants  increase  with  extraordinary  and 
fatal  rapidity.  Though  they  are  really  one- 
celled,  and  reproduce  by  cell-division,  they  often 
hang  together  in  rude  lumps  or  clusters  which 
simulate  to  some  extent  the  many-celled  bodies. 
In  this  book,  however,  where  we  have  concen- 
trated our  attention  mainly  on  the  true  or  green 
plants,  I  have  not  thought  it  well  to  dwell  at 
any  length  on  the  habits  or  structure  of  these 
animal-like  organisms. 

Another  well-known  group  of  small  fungus- 
like  plants  is  that  which  contains  the  yeast- 
fungus,  a  one-celled  plant,  which  reproduces  by 
budding. 

The  higher  fungi  are  many-celled,  and  often 
possess  well-marked  organs  for  different  pur- 
poses. They  answer  rather  to  the  seaweeds 
and  higher  alga.  Familiar  examples  are  the 
common  moulds,  which  form  on  jam,  dead 
fruit,  and  other  decaying  material.  Some  of 
them,  like  the  smut  of  wheat  and  oats,  are 
parasitic  on  growing  plants,  and  most  dangerous 
enemies  to  green  vegetation.  The  highest  fungi 
are  the  groups  which  include  the  mushroom, 
the  puff-ball,  and  all  those  other  large  and 
curiously-shaped  forms  commonly  lumped  to- 


228        THE  STORY  OF  THE  PLANTS. 

gether  in  popular  language  under  the  name  of 
toadstools.  Their  anatomy  and  physiology  is 
extremely  complex. 

To  recapitulate  ;  CELLULAR  PLANTS  belong  to 
two  main  types  ;  those  which  contain  chlorophyll, 
and  live  like  plants  by  eating  and  assimilating 
carbon  under  the  influence  of  sunshine ;  these 
are  generally  grouped  together  in  a  rough  class  as 
ALG.E  :  and  those  which  contain  no  chlorophyll, 
but  live,  like  animals,  by  using  up  or  destroying 
the  carbon-compounds  already  stored  up  by 
green  plants ;  these  are  generally  grouped  to- 
gether in  a  rough  class  as  FUNGI. 

The  lichens  form  a  curious  mixed  group, 
whose  strange  habits  cannot  here  be  described 
at  any  adequate  length ;  they  are  not  so  much 
separate  plants  as  united  colonies  of  algae  and 
fungi,  in  which  the  green  alga  does  the  main 
work  of  collecting  food,  while  the  parasitic 
fungus,  increasing  with  it  at  the  same  rate,  eats 
it  up  in  part,  while  contributing  in  turn  in  various 
ways  to  the  general  good  of  the  compound 
community.  This  is  therefore  hardly  a  case  of 
pure  destructive  parasitism,  but  rather  one  of 
a  co-operative  society  banded  together  on  pur- 
pose for  mutual  advantage. 

The  mosses  and  liverworts,  once  more,  show 
us  an  intermediate  stage  between  the  true 
cellular  and  the  true  vascular  plants.  They 
have  a  rudimentary  stem,  and  beginnings  of 
vessels,  r  They  have  also  leaves,  or'~  organs 
equivalent  to  them  ;  and  they  display  the  first 
approach  to  something  like  flowers. 


THE    PAST    HISTORY    OF   PLANTS.  229 

r 

The  VASCULAR  PLANTS,  again,  which  are 
characterised  by  the  possession  of  special  vessels 
for  the  conveyance  of  sap  and  organised  material, 
and  by  the  presence  of  more  or  less  woody  fibres, 
are  divisible  into  two  main  groups — iheflowerless, 
and  the  flowering. 

The  flcnverless  group  of  Vascular  Plants  are 
mainly  represented  by  the  ferns  and  horsetails. 
These  were  at  one  time  the  leading  vegetation 
of  the  entire  world,  far  outnumbering  in  kinds 
all  the  rest  put  together.  But  they  have  now 
been  lived  down  by  the  flowering  plants,  which 
at  present  compose  the  main  mass  of  the  plant 
aristocracy. 

The  flowering  plants,  once  more,  fall  into  two 
main  groups ;  the  small  but  widespread  group  of 
naked-seeded  plants ,  including  the  cycads,  pines, 
firs,  cypresses,  and  yews;  and  the  very  large 
group  of  fruit-bearing  plants,  including  almost 
all  the  kinds  of  herb,  shrub,  bush,  or  tree 
familiarly  known  to  you,  as  well  as  almost  all 
those  various  plants  with  which  we  have  busied 
ourselves  in  this  little  volume.  You  will  thus 
see  that  the  vast  majority  of  species  in  the 
vegetable  kingdom  belong  to  small  and  relatively 
inconspicuous  orders.  Indeed,  for  the  most 
part,  we  habitually  disregard  the  cellular  plants, 
thinking  only  of  the  vascular ;  while  among  the 
vascular  themselves,  again,  we  disregard  the 
flowerless,  thinking  only  of  the  flowering;  and 
among  the  flowering  kinds,  we  concentrate  our 
attention  as  a  rule  on  the  fruit-producing  group 
(in  the  botanical  sense  of  the  word')  and  neglect 
the  naked-seeded.  In  short,  we  usually  confine 


230        THE  STORY  OF  THE  PLANTS. 

our  attention  to  the  highest  division  of  the 
highest  group  of  the  highest  half  of  the  vegetable 
kingdom.  The  rest  are  for  us  mere  inconspicu- 
ous mosses,  moulds,  or  seaweeds. 

The  fruit-producing  group  of  flowering  plants 
are  finally  divided  into  the  dicotyledons  and  the 
monocotyledons,  whose  chief  differences  I  have 
already  pointed  out  to  you.  And  to  complete 
our  picture  of  this  infinite  hierarchy,  the  dicoty- 
ledons, once  more,  are  divided  into  various 
families,  such  as  the  buttercups,  the  roses,  the 
crucifers,  the  composites,  the  labiates,  the 
umbellates,  the  saxifrages,  and  the  catkin- 
bearers.  The  buttercup  family,  in  particular  (to 
select  a  single  group),  is  further  divisible  into 
genera,  such  as  buttercup,  marsh  marigold, 
larkspur,  anemone,  clematis,  and  aconite  ;  while 
the  buttercup  genus  (to  take  one  only  among 
these)  comprises  in  turn  a  vast  number  of 
species,  such  as  the  water-crowfoot,  the  ivy- 
leaved  crowfoot,  the  meadow  buttercup,  the 
bulbous  buttercup,  the  lesser  celandine,  the 
goldilocks,  and  so  on  for  pages.  Similarly,  the 
monocotyledons  are  divided  into  various  families, 
such  as  the  orchids,  lilies,  grasses,  and  sedges : 
the  families  are  divided  into  many  genera ;  and 
each  genus  into  several  species.  The  infinite 
variety  of  circumstances  is  such  that  each  type 
goes  on  varying  and  varying  for  ever  in  order  to 
nt  itself  for  the  endless  situations  it  is  called 
upon  to  fill,  and  the  endless  diversity  in  the 
accidents  of  climate  or  soil  or  position  that  it 
may  chance  to  come  across.  Thus  we  have  in 
England* more  than  a  hundred  different  kinds  of 


THE    PAST   HISTOEY   OF    PLANTS.  231 

grasses,  each   specially  adapted  for   some   one 
particular  situation. 

Only  the  closest  individual  study  can  give  any 
adequate  idea  of  this  immense  diversity  of 
plants  in  nature. 

The  geological  history  of  the  world  shows  us 
that  the  development  of  plants  has  been  slow 
and  progressive.  In  the  earliest  rocks  (of  which 
an  account  is  given  in  another  volume  of  this 
series),  we  get  few  traces  of  any  plants  but  the 
lowest :  so  that  at  that  time  it  is  probable  none 
but  seaweeds  and  their  like  existed — cellular 
plants  which  contain  hardly  any  parts  solid 
enough  for  preservation.  By  the  age  when  the 
coal  was  laid  down,  however,  ferns,  horsetails, 
ami  many  gigantic  extinct  plants  with  solid 
stems  had  begun  to  exist ;  but  few  or  no  flower- 
ing plants,  except  conifers,  had  yet  been  de- 
veloped. Lajer  still  came  the  true  flowering 
plants,  witrTcovered  seeds ,  at  first  in  simple  and 
antiquated  forms,  but  becoming  more  complex 
as  birds,  mammals,  and  flying  insects  of  the 
flower-haunting  types  were  developed  side  by 
side  with  them  to  visit  and  fertilise  them  or  to 
disperse  their  seeds.  Succulent  fruits,  of  course, 
could  only  arise  when  tribes  of  fruit-eaters  had 
been  evolved  to  assist  them  ;  while  such  special 
bee-fertilised  types  as  the  sage  group,  and  such 
complex  forms  as  the  orchids  and  composites, 
requiring  the  aid  of  highly-developed  insects, 
are  of  extremely  recent  evolution.  Plant  and  J 
animal 'life  have  continually  reacted  upon  one  j 
another. 


232       THE  STOKY  OF  THE  PLANTS. 

Whoever  has  been  interested  in  the  study  of 
plants  by  this  little  book  may  be  glad  to  know 
what  is  the  best  way  of  continuing  his  acquaint- 
ance with  the  subject  in  future.  Nothing 
gives  one  such  a  grasp  of  the  facts  of  botany 
and  of  life  in  general  as  careful  study  of  the 
plants  which  grow  in  one's  own  country. 
Students  in  the  British  Isles  should  therefore 
buy  a  copy  of  Bentham  and  Hooker's  British 
Flora,  and  seek  by  the  aid  of  the  key  at  its 
beginning  to  identify  for  themselves  every 
flowering  plant  they  come  across  in  our  woods 
and  meadows.  American  students  should  get 
in  like  manner  Asa  Gray's  Manual  of  Botany.  In 
the  course  of  identifying  all  the  plants  you  find, 
you  will  begin  to  understand  the  nature  of  plant 
life  and  the  course  of  plant  evolution  in  a  way 
that  is  quite  impossible  through  any  mere 
book-reading.  Buy  also  a  simple  platyscopic 
lens,  and  a  sharp  penknife  to  assist  you  in 
dissection.  Armed  with  these  simple  but  useful 
tools,  you  will  soon  make  rapid  and  solid  progress 
in  the  knowledge  of  nature. 

For  further  and  more  detailed  information  on 
the  laws  of  plant  life,  you  cannot  do  better  than 
consult  Kerner  and  Oliver's  Natural  History  of 
Plants,  which  sets  forth  in  full  an  immense 
number  of  interesting  and  curious  facts,  in 
language  comprehensible  to  any  attentive  and 
careful  student. 


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