﻿Stability 
  and 
  Real 
  Atavism 
  179 
  

  

  of 
  the 
  same 
  variety 
  have 
  been 
  derived 
  in 
  this 
  

   way 
  from 
  one 
  primitive, 
  aberrant 
  individual. 
  

   We 
  may 
  disregard 
  variegated 
  leaves, 
  spotted 
  or 
  

   marked 
  with 
  white 
  or 
  yellow, 
  because 
  they 
  are 
  

   too 
  inconstant 
  types. 
  

  

  We 
  may 
  next 
  turn 
  our 
  attention 
  to 
  the 
  va- 
  

   rieties 
  of 
  trees 
  with 
  cut 
  leaves, 
  as 
  the 
  oak- 
  

   leaved 
  Laburnum, 
  the 
  parsley-leaved 
  vine 
  and 
  

   the 
  fern-leaved 
  birch. 
  Here 
  the 
  margin 
  of 
  the 
  

   leaves 
  is 
  deeply 
  cut 
  and 
  divided 
  by 
  many 
  

   incisions, 
  which 
  sometimes 
  change 
  only 
  the 
  

   outer 
  parts 
  of 
  the 
  blade, 
  but 
  in 
  other 
  cases 
  may 
  

   go 
  farther 
  and 
  reach, 
  or 
  nearly 
  reach, 
  the 
  mid- 
  

   vein, 
  and 
  change 
  the 
  simple 
  leaf 
  into 
  a 
  seem- 
  

   ingly 
  compound 
  structure. 
  The 
  anomaly 
  may 
  

   even 
  lead 
  to 
  the 
  almost 
  complete 
  loss 
  of 
  all 
  the 
  

   chorophyll-tissue 
  and 
  the 
  greater 
  part 
  of 
  the 
  

   lateral 
  veins, 
  as 
  in 
  the 
  case 
  of 
  the 
  cut-leaved 
  

   beech 
  or 
  Fagus 
  .sylvatica 
  pectinata. 
  

  

  Such 
  varieties 
  are 
  often 
  apt 
  to 
  revert 
  by 
  buds 
  

   to 
  the 
  common 
  forms. 
  The 
  cut-leaved 
  beech 
  

   sometimes 
  reverts 
  partially 
  only, 
  and 
  the 
  

   branches 
  often 
  display 
  the 
  different 
  forms 
  of 
  

   cut-leaved, 
  fern-like, 
  oak-leaved 
  and 
  other 
  vari- 
  

   ously 
  shaped 
  leaves 
  on 
  the 
  same 
  twigs. 
  But 
  

   this 
  is 
  merely 
  due 
  to 
  the 
  wide 
  variability 
  of 
  the 
  

   degree 
  of 
  fissure 
  and 
  is 
  to 
  be 
  considered 
  only 
  as 
  

   a 
  fluctuation 
  between 
  somewhat 
  widely 
  distant 
  

   extremes, 
  which 
  may 
  even 
  apparently 
  include 
  

  

  