﻿Latent 
  Characters 
  217 
  

  

  The 
  primary 
  leaves, 
  following 
  the 
  seed-leaves, 
  

   are 
  different 
  in 
  many 
  species 
  from 
  the 
  later 
  

   ones, 
  and 
  the 
  difference 
  is 
  extremely 
  pro- 
  

   nounced 
  in 
  some 
  cases 
  of 
  reduction. 
  Often, 
  

   when 
  leaves 
  are 
  lacking 
  in 
  the 
  adult 
  plant, 
  be- 
  

   ing 
  replaced 
  by 
  flattened 
  stalks 
  as 
  in 
  the 
  case 
  

   of 
  the 
  acacias, 
  or 
  by 
  thorns, 
  or 
  green 
  stems 
  and 
  

   twigs 
  as 
  in 
  the 
  prickly 
  broom 
  or 
  Ulex 
  europaeus, 
  

   the 
  first 
  leaves 
  of 
  the 
  young 
  plant 
  may 
  be 
  more 
  

   highly 
  differentiated, 
  being 
  pinnate 
  in 
  the 
  first 
  

   case 
  and 
  bearing 
  three 
  leaflets 
  in 
  the 
  second 
  in- 
  

   stance. 
  This 
  curious 
  behavior 
  which 
  is 
  very 
  

   common, 
  brings 
  the 
  plants, 
  when 
  young, 
  nearer 
  

   to 
  their 
  allies 
  than 
  in 
  the 
  adult 
  state, 
  and 
  mani- 
  

   festly 
  implies 
  that 
  the 
  more 
  perfect 
  state 
  of 
  

   the 
  leaves 
  is 
  latent 
  throughout 
  the 
  life 
  of 
  the 
  

   plant, 
  with 
  the 
  exception 
  of 
  the 
  early 
  juvenile 
  

   period. 
  

  

  Eucalyptus 
  Globulus, 
  the 
  Australian 
  gum- 
  

   tree, 
  has 
  opposite 
  and 
  broadly 
  sessile 
  leaves 
  

   during 
  the 
  first 
  years 
  of 
  its 
  life. 
  Later 
  these 
  

   disappear 
  and 
  are 
  replaced 
  by 
  long 
  sickle- 
  

   shaped 
  foliage 
  organs, 
  which 
  seem 
  to 
  be 
  scat- 
  

   tered 
  irregularly 
  along 
  the 
  branches. 
  The 
  juve- 
  

   nile 
  characters 
  manifestly 
  lie 
  dormant 
  during 
  

  

  */ 
  

  

  the 
  adult 
  period, 
  and 
  that 
  this 
  is 
  so, 
  may 
  be 
  

   shown 
  artificially 
  by 
  cutting 
  off 
  the 
  whole 
  crown 
  

   of 
  the 
  tree, 
  when 
  the 
  stem 
  responds 
  by 
  produc- 
  

   ing 
  numerous 
  new 
  branches, 
  which 
  assume 
  the 
  

  

  