﻿MOSSES, 
  LIVEKWOKTS, 
  AND 
  FERNS 
  

  

  269 
  

  

  formed. 
  Special 
  anthericlial 
  heads 
  produce 
  antheridia 
  and 
  

   sperms, 
  and 
  special 
  archegonial 
  heads 
  produce 
  archegonia 
  and 
  

   eggs. 
  The 
  sperm 
  unites 
  with 
  the 
  egg 
  within 
  the 
  archegonium 
  

   on 
  the 
  underside 
  of 
  the 
  archegonial 
  head, 
  thus 
  forming 
  the 
  

   oospore. 
  The 
  oospore 
  grows 
  and 
  produces 
  an 
  inconspicuous 
  

   sporophyte, 
  which 
  in 
  turn 
  produces 
  asexual 
  spores. 
  1 
  

  

  255. 
  General 
  facts 
  about 
  ferns. 
  The 
  third 
  great 
  division 
  of 
  

   the 
  plant 
  kingdom 
  is 
  usually 
  spoken 
  of 
  as 
  the 
  ferns 
  (pteri- 
  

   dopliytes). 
  The 
  group 
  includes 
  other 
  classes, 
  two 
  of 
  which 
  are 
  

  

  nn 
  

  

  if] 
  -\s^ 
  \i 
  'fjr^/'jl/^S'Tj 
  

  

  B 
  ''rh 
  ' 
  

   FIG. 
  206. 
  A 
  common 
  liverwort 
  (Marchantia) 
  

  

  A, 
  an 
  antheridial 
  plant; 
  B, 
  an 
  archegonial 
  plant 
  ; 
  rhizoids 
  (rh) 
  and 
  midrib 
  (m) 
  

   of 
  the 
  leaf-like 
  flattened 
  body 
  (I) 
  ; 
  capsules 
  (c), 
  in 
  which 
  vegetative 
  reproductive 
  

   buds 
  are 
  formed; 
  the 
  upright 
  stalks 
  (s) 
  are 
  antheridial 
  () 
  and 
  archegonial 
  (or), 
  

   the 
  latter 
  being 
  distinguished 
  by 
  peculiar 
  rays 
  (r). 
  Slightly 
  more 
  than 
  natural 
  size 
  

  

  the 
  scouring 
  rushes, 
  or 
  horsetails, 
  and 
  the 
  club 
  mosses. 
  There 
  

   is 
  good 
  evidence 
  that 
  ferns 
  were 
  formerly 
  more 
  numerous 
  upon 
  

   the 
  earth 
  than 
  they 
  now 
  are, 
  and 
  some 
  of 
  the 
  early 
  ferns 
  were 
  

   of 
  much 
  larger 
  size 
  than 
  those 
  that 
  now 
  exist. 
  During 
  the 
  times 
  

   when 
  coal 
  was 
  being 
  formed 
  most 
  abundantly, 
  ferns 
  and 
  their 
  

   near 
  relatives 
  composed 
  a 
  conspicuous 
  part 
  of 
  the 
  flora. 
  Some 
  

  

  1 
  Discussion 
  of 
  the 
  different 
  kinds 
  of 
  liverworts 
  and 
  the 
  details 
  of 
  liver- 
  

   wort 
  reproduction 
  are 
  not 
  important 
  for 
  most 
  elementary 
  classes. 
  In 
  special 
  

   cases 
  where 
  it 
  is 
  deemed 
  best 
  to 
  make 
  further 
  study, 
  see 
  Bergen 
  and 
  Davis. 
  

   Principles 
  of 
  Botany. 
  

  

  