﻿17^ 
  BOTANICAL 
  GAZETTE. 
  [J^b'' 
  

  

  ally 
  bringing 
  to 
  them 
  the 
  crude 
  materials 
  from 
  which 
  starch, 
  fats, 
  pro- 
  

   teids, 
  etc., 
  are 
  made. 
  Hence 
  the 
  necessity 
  for 
  a 
  well 
  developed 
  vascular 
  

   system 
  in 
  connection 
  with 
  the 
  floral 
  organs. 
  For 
  it 
  is 
  w^ell 
  known 
  that 
  

   water 
  travels 
  through 
  wood 
  vessels, 
  and 
  Haberlandt 
  (among 
  others) 
  has 
  

   shown* 
  that 
  there 
  is 
  a 
  close 
  parallel 
  between 
  the 
  water 
  conducting 
  power 
  

   of 
  a 
  tissue 
  and 
  the 
  number 
  of 
  its 
  vessels 
  and 
  tracheids. 
  

  

  But 
  a 
  current 
  of 
  water 
  implies 
  evaporation. 
  Otherwise 
  there 
  could 
  

   .be 
  no 
  current, 
  only 
  stagnation. 
  Moreover 
  a 
  large 
  proportion 
  of 
  the 
  

   water 
  in 
  which 
  these 
  dissolved 
  substances 
  are 
  carried 
  is 
  not 
  itself 
  needed 
  

   for 
  growth 
  (at 
  least 
  not 
  after 
  the 
  flowers 
  have 
  expanded) 
  or 
  for 
  food 
  man- 
  

   ufacture. 
  It 
  must 
  be 
  gotten 
  rid 
  of 
  that 
  more 
  water 
  containing 
  needed 
  

   working 
  materials 
  may 
  take 
  its 
  place. 
  The 
  rapid 
  withering 
  of 
  cut 
  flow- 
  

   ers 
  18 
  the 
  logical 
  result 
  of 
  this 
  process 
  and 
  the 
  proof 
  of 
  evaporation. 
  Mi- 
  

   croscopic 
  eximination 
  shows, 
  too, 
  that 
  in 
  addition 
  to 
  the 
  commonly 
  deli- 
  

   cate 
  character 
  of 
  the 
  floral 
  organs 
  (and 
  envelopes 
  in 
  many 
  cases), 
  this 
  

   transpiration 
  is 
  often 
  aided 
  here, 
  as 
  from 
  leaf 
  surfaces, 
  by 
  the 
  presence 
  of 
  

   stomata. 
  Stadler 
  flnds 
  the 
  secretion 
  of 
  honey 
  through 
  stomata 
  to 
  be 
  the 
  

   "commonest 
  case."^ 
  The 
  fact, 
  too, 
  noticed 
  by 
  MiUler 
  and 
  others, 
  that 
  

   honey 
  issecreted 
  only 
  under,certain 
  conditions 
  of 
  temperature 
  and 
  sun- 
  

   hght, 
  points 
  to 
  the 
  conclusion 
  that 
  it 
  is 
  of 
  the 
  nature 
  of, 
  or 
  stands 
  in 
  

   close 
  relation 
  to, 
  evaporation. 
  

  

  _ 
  It 
  IS 
  a 
  well 
  known 
  fact 
  that 
  some 
  plants, 
  which 
  grow 
  in 
  soil 
  contain- 
  

   ing 
  much 
  hme, 
  have 
  upon 
  their 
  leaves 
  deposits 
  of 
  calcium 
  which.carried 
  

   m 
  solution 
  through 
  the 
  plant, 
  have 
  been 
  left 
  behind 
  when 
  the 
  water 
  was 
  

   evaporated 
  ; 
  e. 
  g.^ 
  species 
  of 
  saxifrage. 
  

  

  Fmally 
  we 
  have 
  to 
  notice 
  the 
  immediate 
  connection 
  with 
  the 
  nee 
  

   tary 
  on 
  the 
  one 
  hand, 
  and 
  with 
  the 
  vascular 
  tissue 
  on 
  the 
  other, 
  of 
  chlor- 
  

   ophyll 
  bearing 
  cells, 
  i. 
  e., 
  of 
  cells 
  in 
  which 
  the 
  crude 
  materials 
  brought 
  

   by 
  the 
  water 
  through 
  the 
  vessels 
  may 
  be 
  united 
  with 
  carbon 
  to 
  form 
  

   starch, 
  with 
  which, 
  again, 
  other 
  organic 
  compounds 
  may 
  be 
  produced. 
  

   These 
  substances 
  travel 
  by 
  osmosis. 
  from 
  cell 
  to 
  cell 
  until 
  they 
  reach 
  the 
  

   stomata, 
  if 
  there 
  are 
  any, 
  or 
  the 
  subepidermal-layer 
  of 
  cells 
  from 
  which 
  

   water 
  ,8 
  continually 
  being 
  drawn 
  by 
  vigorous 
  surface 
  evaporation. 
  As 
  

   the 
  hme-laden 
  water 
  of 
  saxifrage 
  takes 
  some 
  of 
  its 
  burden 
  to 
  the 
  very 
  

   end 
  of 
  Its 
  course, 
  leaving 
  it 
  only 
  when 
  the 
  force 
  of 
  vaporizatbn 
  puH^ 
  

   wrrl:"W^'' 
  '""'"' 
  ^^^^^°g 
  improbable 
  in 
  the 
  supposition 
  that 
  

   Ir 
  thfr^ 
  ^'i 
  T""^^' 
  °"'-^ 
  comparatively 
  speaking) 
  charged 
  with 
  su- 
  

   tiHH« 
  U 
  Itr 
  ^°^ 
  ™ 
  °^ 
  '^^''^^' 
  '^^^«"'d 
  ^^^^Y 
  some 
  of 
  that 
  with 
  it 
  un- 
  

  

  Sfl 
  it 
  VT?'^' 
  ''"^'^^S 
  '' 
  '^^'^ 
  ^« 
  ^ 
  saccharine 
  deposit. 
  

   arisBs 
  frl 
  J, 
  Vk 
  ! 
  V"" 
  "''^'^^ 
  ^"^■'^^^^ 
  of 
  tl^e 
  cases 
  observed 
  the 
  gluCO« 
  

   (SvTonh 
  W. 
  '"f 
  ' 
  •'^*"*^" 
  °^ 
  ^^^'^h; 
  in 
  a 
  few 
  cases 
  from 
  fatty 
  oilB 
  

   into 
  B 
  ar;h 
  T/'^'k 
  '■ 
  '-° 
  °*^^^^ 
  ^^°^ 
  ^^^^i^' 
  ^W^h 
  is 
  easily 
  converted 
  

  

  'BeUragezurKenntni^derCrr'ie'n.irs. 
  

  

  