﻿Miscellaneous. 
  443 
  

  

  and 
  the 
  structure 
  of 
  the 
  parts 
  of 
  the 
  mouth 
  and 
  the 
  limbs, 
  as 
  well 
  

   as 
  the 
  relative 
  number 
  of 
  the 
  segments, 
  may 
  have 
  been 
  very 
  

   different 
  (leaving 
  quite 
  out 
  of 
  consideration 
  the 
  very 
  different 
  form 
  

   of 
  the 
  extremity 
  of 
  the 
  abdomen). 
  — 
  Anzeiger 
  d. 
  k. 
  Alcad. 
  Wis*. 
  

   Wien, 
  December 
  13, 
  1888, 
  p. 
  247. 
  

  

  On 
  the 
  Formation 
  of 
  the 
  Aniherozoids 
  of 
  the 
  Characea3. 
  

   By 
  M. 
  Leon 
  Guignauu. 
  

  

  The 
  antherozoids 
  of 
  the 
  Characea?, 
  Muscinea3, 
  and 
  vascular 
  Cryp- 
  

   togamia 
  have 
  the 
  form 
  of 
  a 
  spiral 
  filament 
  furnished 
  with 
  cilia, 
  

   originating 
  by 
  special 
  metamorphosis 
  of 
  the 
  contents 
  of 
  the 
  mother- 
  

   cell. 
  In 
  its 
  formation 
  the 
  nucleus 
  of 
  the 
  mother- 
  cell 
  plays 
  an 
  essen- 
  

   tial 
  part 
  ; 
  it 
  does 
  not 
  dissolve, 
  as 
  was 
  at 
  first 
  supposed, 
  but 
  concurs 
  

   directly 
  in 
  furnishing 
  the 
  body 
  of 
  the 
  antherozoid, 
  while 
  the 
  cilia 
  

   proceed 
  solely 
  from 
  the 
  protoplasm. 
  

  

  But 
  is 
  the 
  body 
  of 
  the 
  antherozoid 
  solely 
  derived 
  from 
  the 
  

   nucleus 
  or 
  both 
  from 
  the 
  nucleus 
  and 
  the 
  protoplasm 
  ? 
  If 
  it 
  is 
  fur- 
  

   nished 
  by 
  the 
  nucleus 
  alone, 
  nourished 
  by 
  all 
  the 
  portion 
  of 
  the 
  

   protoplasm 
  which 
  is 
  not 
  employed 
  in 
  the 
  formation 
  of 
  the 
  cilia, 
  how 
  

   is 
  this 
  metamorphosis 
  effected 
  ? 
  If, 
  on 
  the 
  contrary, 
  the 
  protoplasm 
  

   furnishes 
  a 
  portion 
  of 
  the 
  body, 
  does 
  the 
  differentiation 
  of 
  the 
  spiral 
  

   filament 
  commence 
  at 
  the 
  expense 
  of 
  the 
  protoplasm 
  and 
  not 
  of 
  the 
  

   nucleus, 
  as 
  has 
  recently 
  been 
  asserted 
  ? 
  Lastly, 
  how 
  and 
  at 
  what 
  

   moment 
  do 
  the 
  cilia 
  originate? 
  These 
  are 
  so 
  many 
  general 
  ques- 
  

   tions 
  upon 
  which 
  the 
  extant 
  data 
  are 
  insufficient 
  or 
  contradictory. 
  

  

  By 
  a 
  comparative 
  study 
  of 
  the 
  various 
  groups 
  of 
  Cryptogamia 
  the 
  

   author 
  has 
  been 
  enabled 
  to 
  clear 
  up 
  the 
  doubtful 
  points, 
  and 
  has 
  

   arrived 
  at 
  results 
  the 
  agreement 
  and 
  generality 
  of 
  which 
  render 
  

   them 
  interesting. 
  In 
  the 
  present 
  note 
  he 
  deals 
  with 
  the 
  Characeae. 
  

  

  In 
  these 
  plants 
  the 
  antheridian 
  filaments 
  are 
  formed 
  of 
  super- 
  

   posed 
  discoidal 
  joints, 
  which 
  represent 
  the 
  mother-cells 
  of 
  the 
  anthe- 
  

   rozoids. 
  To 
  ascertain 
  the 
  parts 
  played 
  by 
  the 
  nucleus 
  and 
  proto- 
  

   plasm 
  in 
  the 
  formation 
  of 
  the 
  latter 
  these 
  cells 
  must 
  be 
  dissociated 
  

   and 
  their 
  contents 
  carefully 
  isolated 
  after 
  fixation 
  and 
  hardening. 
  

   By 
  various 
  methods 
  of 
  double 
  coloration 
  the 
  substance 
  of 
  the 
  

   nucleus 
  may 
  be 
  very 
  clearly 
  distinguished 
  from 
  that 
  of 
  the 
  proto- 
  

   plasm, 
  and 
  all 
  stages 
  of 
  the 
  development 
  may 
  be 
  followed 
  step 
  by 
  

   step. 
  

  

  At 
  the 
  moment 
  when 
  the 
  antherozoid 
  is 
  about 
  to 
  originate 
  the 
  

   nucleus 
  moves 
  to 
  the 
  side 
  of 
  the 
  mother-cell, 
  so 
  that 
  its 
  outer 
  sur- 
  

   face 
  is 
  only 
  covered 
  by 
  a 
  very 
  thin 
  layer 
  of 
  hyaline 
  protoplasm. 
  

   On 
  this 
  outer 
  surface 
  a 
  small 
  thickening-band 
  afterwai'ds 
  appears, 
  

   more 
  refractive 
  than 
  the 
  rest 
  of 
  the 
  nucleus 
  which 
  produces 
  it 
  by 
  a 
  

   special 
  metamorphosis 
  of 
  its 
  substance. 
  This 
  band 
  forms 
  part 
  of 
  

   the 
  nucleus 
  without 
  producing 
  a 
  salient 
  crest 
  on 
  its 
  outer 
  surface, 
  

   and 
  following 
  its 
  contour 
  it 
  resembles 
  a 
  short 
  and 
  very 
  open 
  crescent. 
  

  

  