568 
JOURNAL  OF  HORTICULTURE  AND  COTTAGE  GARDENER. 
December  10,  1896 
good  late  Grapes  yet  remain.  Mr.  Radcliffe,  the  owner,  is  constantly 
improving  his  garden  and  enlarging  his  estates.  Outdoor  planting  is 
receiving  special  attention,  and  many  valnable  additions  are  being  made. 
The  whole  is  being  well  carried  out  by  Mr.  J.  Bedford,  the  gardener,  who 
has  had  charge  there  for  many  years. — Rdstious. 
The  forms,  STRUCTURE  and  FUNCTIONS  of  LEAVES. 
Botanists  divide  leaves  into  three  classes — floral,  scale,  and  foliage 
leaves,  but  the  most  important  are  the  foliage  leaves. 
The  flat  or  expanded  portion  of  leaves  is  termed  the  lamina  or 
blade.  It  assames  different  forms,  which  are  almost  endless  in  variety. 
They  may,  however,  be  grouped  under  two  heads — simple  and  compound. 
Simple  leaves  are  all  in  one  part,  frequently  with,  but  sometimes 
without  divisions.  In  the  simple  forms  the  divisions  are  only  partial. 
When  the  divisions  reach  the  midrib  the  leaf  becomes  a  compound 
form.  Some  simple  leaves  are  so  very  deeply  cut  that  it  becomes  a 
question  whether  they  are  simple  or  compound. 
The  leafstalk  when  present  is  termed  the  petiole,  and  varies  in  length 
with  different  leaves.  The  leaves  of  some  plants,  for  instance  the 
Wallflower,  have  no  petioles,  they  are  then  sessile  on  the  stem,  sitting 
upon  it  as  it  were. 
At  the  base  of  the  petioles  or  leafstalks  there  are  to  be  found  projec¬ 
tions  which  are  termed  stipules.  They  are  prominent  on  the  petiole  of 
the  Apple  leaf  and  Rose  leaf.  The  stipules  are  extraordinarily  developed 
in  the  Lathyrus  or  Pea  tribe,  while  the  real  leaf  and  also  the  petiole  are 
converted  into  tendrils. 
Some  plants  have  structures  which  look  like  leaves  but  which  are 
not  leaves.  In  the  Butcher’s  Broom  we  find  flowers  spring  from  what 
appears  to  be  the  surface  of  leaves,  but  which  are  really  flattened  branches ; 
in  the  older  the  fruit  will  be  found.  When  we  find  a  flower  or  fruit 
on  what  we  consider  to  be  a  leaf,  then  we  have  positive  evidence  that 
it  is  not  a  leaf  but  a  branch. 
The  green  flattened  structure  which  is  the  most  expanded  on  the 
Australian  Acacias  into  a  leaf-like  form  is  really  the  petiole  or  leaf¬ 
stalk,  the  real  leaves  being  stunted.  The  prickles  on  the  common  Furze 
are  the  structures  which  serve  these  plants  as  leaves.  The  flattened 
stems  of  the  Cactus  tribe  fulfil  the  functions  of  leaves. 
The  size  and  form  of  leaves  have  something  to  do  with  the  size 
and  thickness  of  stem.  The  leaf  is  best  adapted  for  that  particular 
stem  on  which  it  is  found,  but  we  do  not  find  generally  big  leaves  on 
small  stems. 
The  sub-kingdom  of  flowering  plants  is  divided  into  two  classes — 
dicotyledons  and  monocotyledons.  Both  these  classes  exhibit  differences 
more  or  less  in  all  the  parts,  but  one  of  the  chief  diflierences  lies  in  the 
evident  structure  of  the  leaves.  In  the  dicotyledon  class  the  leaves  are 
always  net  veined  ;  in  the  monocotyledons  they  are  parallel  veined. 
Grasses  and  cereals  are  examples  of  the  latter,  while  the  former  embraces 
a  great  variety  of  trees,  shrubs  and  plants. 
It  is  interesting  to  know  what  a  leaf  consists  of  beyond  what  we 
can  see  with  the  naked  eye. 
A  leaf  consists  of  several  layers  of  cells.  On  the  surface  there  is 
the  epidermis  or  protective  layer  of  flat  cells.  The  layer  immediately  on 
the  surface  is  the  cuticle,  and  from  this  in  many  plants  there  are 
prolongations  of  some  of  the  cells  into  what  we  know  as  hairs ;  they 
are  usually  very  fine  and  only  contain  one  cell.  Next  to  the  cuticle 
there  is  a  layer  of  large  cells  constituting  the  epidermis  proper,  and  it  is 
very  probable  the  single-celled  hairs  are  also  connected  with  this  layer, 
the  cuticle  simply  being  a  thin  outer  covering.  Much  larger  cells  are 
then  arranged  at  right  angles  known  as  pallisade  cells ;  these  contain 
the  chlorophyll,  the  green  colouring  matter.  Below  these  there  are  a 
number  of  stellate  shaped  cells,  not  arranged  closely  together,  but  at 
such  a  distance  that  a  large  amount  of  air  space  is  present.  Air  enters 
the  leaf  by  the  stomata  on  the  under  sides  chiefly,  but  they  are  situated 
both  on  the  upper  and  lower  epidermis,  the  latter  being  the  most 
numerously  furnished  with  them.  The  stomata  are  the  openings  or 
breathing  spaces  of  the  leaves. 
Some  leaves  have  very  fleshy  smooth  surfaces,  others  are  ex¬ 
tremely  woolly  or  hairy.  Fleshy  leaves  are  almost  always  found  on 
plants  which  have  to  live  in  places  of  extreme  drought ;  Sedums,  Agaves, 
and  Aloes  are  examples  of  such.  The  leaves  of  plants  assume  modifi¬ 
cations  according  to  their  environment ;  for  instance,  the  Mullein,  a 
plant  usually  with  very  woolly  leaves,  may  perhaps  be  found  growing 
on  a  hill  with  an  excessive  amount  of  hairs,  while  down  in  the  valley 
it  may  scarcely  have  a  hair  at  all.  The  function  of  the  hairs  is  to 
conserve  moisture.  When  the  environment  of  the  plant  is  such  that 
the  plant  obtains  abundance  of  moisture,  then  the  hairs  are  not  required 
and  they  gradually  die  out  or  are  suppressed.  If  the  plant  has  to  endure 
excessive  dryness  in  a  dry  district  hairs  in  more  abundance  develop. 
Almost  all  water  plants  are  free  from  hairs. 
Water  plants  have  usually  two  kinds  of  leaves.  The  white  Water  Lily, 
Nympbaea  alba,  has  large  upper  leaves  which  float  on  the  surface  of  the 
water,  submitting  a  large  space  of  leaf  surface  to  the  atmosphere.  The 
lower  leaves,  which  are  constantly  submerged,  are  thin  and  narrow  and 
are  capable  of  moving  about. 
One  of  the  chief  functions  of  the  leaves  of  plants  is  to  assimilate 
the  fcod  received  from  the  roots  and  that  taken  in  by  the  stomata  from 
the  atmosphere — namely,  carbon  dioxide  and  free  oxygen.  The  elements 
received  from  the  air  is  gaseous  food,  that  from  the  roots  liquid.  Under 
the  influence  of  light  the  carbon  is  separated  from  the  oxygen.  The 
former  is  fixed  by  the  plant,  the  latter  set  free,  being  restored  to  the 
atmosphere.  The  carbon  also  combines  with  the  water  solution  from  the 
roots,  and  under  the  influence  of  sunlight  with  the  assistance  of  chlorophyll, 
or  green  colouring  matter,  certain  chemical  changes  are  undergone  and 
starch  is  formed.  By  the  action  of  a  ferment  the  starch  is  converted  into 
sugar,  which  becomes  soluble  enough  to  be  translocated  through  the 
whole  plant,  building  up  and  strengthening  existing  parts,  also  forming 
fresh  growth. 
Transpiration  is  an  important  function  of  leaves.  It  is  the  giving  off 
water  as  watery  vapour  ;  it  is  the  great  means  by  which  the  circulation 
of  the  sap  is  carried  on,  because  it  is  evident  that  the  more  moisture  there 
is  passes  away  from  the  leaves  the  more  must  be  drawn  up  from  the  roots. 
Thus,  according  to  the  weather  and  the  amount  of  light  will  the  various 
processes  of  absorption,  assimilation,  transpiration,  and  circulation  be 
carried  on. 
The  green  leaves  of  plants  do  an  immense  work.  We  may  regard 
leaves  as  so  many  nets  and  sails  to  catch  air  and  sunshine  ;  they  are  good 
absorbers  of  both,  and  the  heat  thus  acquired  does  work  of  great 
importance.  With  this  work,  which  may  be  termed  altered  sunshine,  the 
whole  of  our  food  from  the  vegetable  kingdom  is  built  up  and  brought 
into  valuable  form.  If  the  green  leaves  and  other  green  parts  of  plants 
were  to  disappear  from  the  earth  the  results  would  be  disastrous  to  animal 
life,  because  the  leaves  of  plants  take  up  substances  which  would  otherwise 
accumulate.  We  obtain  almost  all  the  necessaries  of  life  directly  or 
indirectly  from  the  action  of  green  leaves  and  other  green  parts  of 
plants,  but  principally  the  leaves.  Thus  the  disposal  of  natural  energy 
is  brought  into  convenient  form  for  food  and  very  many  purposes.  It  is, 
then,  desirable  that  plants  should  receive  as  much  light  in  the  form  of 
sunshine  as  possible. 
The  fall  of  the  leaf  is  essentially  a  vital  process.  When  a  leaf  dies 
on  a  branch  in  summer  it  adheres  more  closely  than  it  would  in  autumn, 
but  when  it  dies  in  the  natural  way  in  autumn  it  separates  easily  from 
the  branch,  leaving  a  scar  where  it  has  been  attached.  Prior  to  the 
fall  of  the  leaf  there  is  a  vast  amount  of  change  going  on,  chiefly  of  a 
chemical  character,  but  yet  considerable  physical  change.  The  material 
likely  to  be  of  further  use  to  the  plant  is  withdrawn  from  the  leaf  and 
stored  up  in  an  available  form  either  in  the  stem  or  root. 
Very  small  quantities  of  waste  material  are  taken  in  with  the  food. 
In  the  annual  fall  of  the  leaf  we  find  that  these  waste  matters  are 
removed  from  the  stem  or  root  into  the  leaf,  and  are  restored  again  to 
the  soil  with  the  annual  fall. — E.  D.  S. 
THE  YOUNG  GARDENERS’  DOMAIN. 
9 
*  A  Beginning. 
As  you  have  kindly  offered  to  devote  space  in  your  valuable  Journal 
to  the  younger  generation  of  the  craft,  I  hope  it  may  be  taken  advantage 
of  in  the  fullest  degree.  It  is  to  be  hoped  that  we  youngsters  shall  be 
enabled  to  prove  that  the  education  of  the  present-day  gardener  is  not 
degenerating,  as  some  of  our  critics  would  at  times  have  us  believe. 
Who  knows  but  from  our  ranks  may  be  found  young  fellows  who  in  time 
to  come  may  have  their  writings  as  much  sought  after  in  their  day  as  the 
writings  of  the  best  of  past  or  present  contributors.  Now,  young  gardeners, 
let  us  try  our  best  to  fit  ourselves  for  a  head  place  in  years  to  come,  with 
the  one  idea  of  reaching  the  topmost  rung  of  the  ladder  if  only  by  our 
own  exertions.  We  shall  lose  nothing  by  trying,  and  there  is  much  to 
be  gained.  We  cannot  lay  in  too  great  a  store  of  knowledge  while  we 
are  young.  We  know  there  are  many  temptations  to  lure  us  away,  but 
let  us  strive  against  them  and  determine  to  become  masters  of  our 
profession.  And  now,  Mr,  Editor,  this  is  the  first  attempt  of,  and  I  hope 
you  will  not  be  too  hard  on — Samuel  Sempee. 
[Our  printers  have  set  up  your  Latin  signature  as  it  appears,  and  as 
it  will  do  very  well  we  do  not  alter  it.  It  is  a  well-written  little 
contribution.  The  observations  taken  out,  though  creditable  to  the 
writer  of  them,  would  be  the  reverse  of  pleasing  to  the  gentleman 
referred  to,  and  he  would  be  pained  by  having  something  attributed  to 
him  to  which  he  has  no  claim.  Try  again.  We  shall  only  be  “hard” 
when  praise  preponderates.] 
The  Cinekaria, 
A  FEW  weeks  ago  we  had  a  suggestion  put  to  us  in  the  way  of 
offering  seasonable  hints  regarding  our  vocation  ;  I,  therefore,  offer  my 
views  on  the  culture  of  the  Cineraria  as  one  of  our  chief  greenhouse 
lants.  To  have  good  plants  for  early  flowering  the  seed  should 
e  sown  in  April  in  light  sandy  soil,  care  being  taken  not  to  sow  too 
thickly,  as  by  so  doing  the  plants  are  drawn  and  weakened.  They 
should  be  sturdy  plants  to  start  with,  and  then  let  it  be  the  aim  of  the 
grower  to  keep  them  so  by  judicious  ventilation.  Draughts  cause  the 
leaves  to  flag,  and  help  to  bring  on  inildew. 
After  sowing,  the  pans  should  be  placed  on  a  gentle  hotbed,  but  when 
the  seedlings  appear  removed  to  a  cooler  position,  and  eventually  into  a 
cold  frame.  When  large  enough  to  handle  let  them  be  pricked  off  in 
pang  of  light  soil,  and  before  they  become  crowded  placed  singly  in  large 
60’s  in  loam,  leaf  soil,  and  decomposed  Mushroom  bed  refuse,  keeping 
the  plants  close  for  a  day  or  two,  and  syringing  rathex'  lightly  twice  a 
day  in  bright  weather.  After  they  become  established  more  air  should 
be  given,  but  avoiding  cold  draughts. 
The  plants  ought  to  be  strong  enough  by  the  end  of  August  to  have  a 
shift  from  GO’S  to  24’8,  in  a  little  heavier  compost,  potting  rather  firmly. 
Care  must  be  taken  not  to  overwater,  but  rather  keep  them  on  the  dry 
side  till  they  have  become  established,  and  even  then  overwatering  is 
