﻿402 
  G. 
  R. 
  Wieland 
  on 
  the 
  Cycadophyta. 
  

  

  Completer 
  accounts 
  of 
  the 
  genera 
  composing 
  the 
  sev- 
  

   eral 
  families 
  just 
  outlined, 
  with 
  notes 
  on 
  the 
  abundance 
  

   and 
  relative 
  range 
  of 
  important 
  forms 
  would 
  find 
  a 
  place 
  

   here. 
  But 
  such 
  extended 
  treatment 
  may 
  fairly 
  be 
  left 
  

   over 
  for 
  incorporation 
  in 
  studies 
  of 
  florae. 
  The 
  two 
  

   diagrams 
  appended 
  will, 
  however, 
  throw 
  some 
  further 
  

   light 
  on 
  the 
  main 
  facts 
  on 
  which 
  the 
  Cycadophyte 
  classi- 
  

   fication 
  must 
  rest. 
  

  

  In 
  the 
  first 
  diagram 
  the 
  approximate 
  time-range 
  and 
  

   relationships 
  of 
  the 
  better 
  known 
  or 
  the 
  more 
  character- 
  

   istic 
  Cycads 
  and 
  Hemicycads 
  are 
  given. 
  To 
  the 
  left 
  are 
  

   the 
  two 
  great 
  persistent 
  dioecious 
  lines 
  with 
  strobili 
  of 
  

   increased 
  size 
  [reaching 
  a 
  weight 
  of 
  100 
  pounds]. 
  It 
  is 
  

   unlikely 
  that 
  large 
  strobili 
  have 
  uniformly 
  characterized 
  

   the 
  cycads. 
  Earlier 
  views 
  have 
  implied 
  this 
  ; 
  but 
  neither 
  

   the 
  record 
  nor 
  theoretic 
  considerations 
  can 
  be 
  here 
  

   invoked. 
  The 
  reduction 
  and 
  consolidation 
  of 
  sporophylls 
  

   into 
  cones 
  is 
  ancient 
  ; 
  and 
  nearly 
  all 
  through 
  the 
  Permian 
  

   and 
  the 
  Trias, 
  sporophylls 
  are 
  small 
  and 
  cones 
  lax. 
  The 
  

   marvelous 
  conservation 
  of 
  the 
  cast 
  Lepidostrobus 
  browni, 
  

   a 
  compact 
  sizable 
  cone, 
  shows 
  that 
  larger 
  sclerous 
  cones 
  

   are 
  preserved 
  as 
  fossils, 
  fortuitously. 
  In 
  North 
  Amer- 
  

   ica 
  just 
  one 
  good 
  Araucaria 
  cone 
  has 
  been 
  recovered. 
  4 
  

  

  The 
  two 
  Cycadalean 
  arrowheads 
  fix 
  the 
  present 
  in 
  the 
  

   diagram 
  then, 
  as 
  the 
  era 
  of 
  specialized 
  great 
  cones, 
  seen 
  

   in 
  conifers 
  also 
  ; 
  while 
  the 
  succeeding 
  arrows 
  show 
  the 
  

   relative 
  persistence, 
  known 
  and 
  inferred, 
  of 
  the 
  lines 
  

   more 
  and 
  more 
  Hemiangiospermous. 
  In 
  a 
  sense 
  these 
  are 
  

   also 
  the 
  more 
  and 
  more 
  generalized 
  groups 
  ; 
  though 
  it 
  is 
  

   doubtless 
  consistent 
  to 
  regard 
  small 
  bisexual 
  flowers 
  as 
  

   denoting 
  specialization. 
  The 
  point 
  is 
  that 
  these 
  were 
  

   near 
  the 
  lines 
  destined 
  to 
  persist; 
  and 
  such, 
  while 
  mak- 
  

   ing 
  fundamental 
  changes 
  early, 
  must 
  from 
  period 
  to 
  

   period 
  hold 
  to 
  some 
  structural 
  mean, 
  passing 
  which 
  

   always 
  ends 
  in 
  extinction. 
  There 
  is 
  then 
  found 
  in 
  these 
  

   groups, 
  combined 
  with 
  varying 
  degrees 
  of 
  specialization, 
  

   a 
  profound 
  underlying 
  relationship 
  to 
  the 
  forms 
  leading 
  

   on 
  to 
  the 
  dominant 
  races 
  of 
  today. 
  

  

  Taking 
  the 
  Zamiae, 
  it 
  is 
  curious 
  to 
  find 
  so 
  fern-like 
  a 
  

   frond 
  as 
  Stangeria, 
  and 
  one 
  so 
  aberrant 
  as 
  Bowenia. 
  

   These 
  forms 
  are 
  more 
  ancient 
  than 
  the 
  record 
  indicates, 
  

   as 
  also 
  the 
  strobilar 
  crown 
  of 
  Cycas. 
  There 
  is 
  no 
  reason 
  

  

  This 
  is 
  the 
  Arauoafia 
  hrxpcra 
  (Wieland, 
  1908), 
  now 
  being 
  more 
  care- 
  

   fully 
  studied 
  in 
  the 
  course 
  of 
  a 
  joint 
  investigation 
  by 
  Dr. 
  Neil 
  E. 
  Stevens 
  

   and 
  myself, 
  taking 
  up 
  the 
  aplosporopliyllous 
  gymnosperms. 
  

  

  