﻿THE 
  MAIOTIC 
  PHASE 
  IN 
  ANIMALS 
  AND 
  PLANTS. 
  541 
  

  

  niaiotic 
  division 
  itself, 
  or 
  as 
  being 
  a 
  second 
  diaschistic 
  

   (heterotype) 
  mitosis. 
  This 
  we 
  have 
  found 
  now 
  not 
  to 
  be 
  

   the 
  case 
  ; 
  for 
  although 
  the 
  details 
  in 
  the 
  second 
  maiotic 
  

   division 
  in 
  these 
  fishes 
  are 
  extreinely 
  difficult 
  to 
  elucidate, 
  

   we 
  have 
  been 
  able, 
  through 
  a 
  careful 
  re-examination, 
  to 
  

   determine 
  that 
  the 
  apparent 
  similarity 
  of 
  the 
  phases 
  in 
  this 
  

   to 
  the 
  first 
  maiotic 
  series 
  is 
  fictitious, 
  and 
  that 
  in 
  reality 
  

   this 
  division 
  has 
  the 
  ordinary 
  pre-maiotic 
  anaschistic 
  

   chai'acters 
  as 
  in 
  other 
  animals 
  and 
  plants. 
  

  

  We 
  have 
  now 
  dealt 
  fully 
  with 
  a 
  typical 
  insect, 
  and 
  several 
  

   El 
  asm 
  ©branch 
  types, 
  and 
  the 
  intention 
  has 
  been 
  to 
  use 
  

   these 
  as 
  illustrations 
  of 
  the 
  manner 
  in 
  which 
  reproductive 
  

   elements 
  become 
  matured 
  in 
  widely 
  sundered 
  classes 
  of 
  

   animal 
  forms. 
  It 
  has 
  been 
  found 
  that 
  so 
  far 
  as 
  these 
  differeut 
  

   examples 
  are 
  concerned 
  there 
  is 
  a 
  complete 
  parallelism 
  among 
  

   them 
  all. 
  It 
  has 
  been 
  shown 
  further 
  that 
  the 
  similarity 
  which 
  

   exists 
  between 
  the 
  reduction 
  in 
  insects 
  and 
  Elasmobranchs 
  

   also 
  subsists 
  between 
  all 
  these 
  zoological 
  examples 
  and 
  the 
  

   various 
  vegetable 
  forms 
  previously 
  described. 
  Throughout 
  

   the 
  whole 
  series 
  the 
  pi'ocess 
  is 
  carried 
  out 
  on 
  an 
  essentially 
  

   similar 
  plan. 
  In 
  themselves, 
  and 
  certainly 
  when 
  we 
  bear 
  in 
  

   mind 
  what 
  has 
  already 
  been 
  ascertained 
  with 
  respect 
  to 
  a 
  host 
  

   of 
  other 
  animal 
  and 
  vegetable 
  forms, 
  the 
  present 
  examples 
  

   would 
  be 
  quite 
  sufficient 
  to 
  indicate 
  that 
  there 
  exists 
  through- 
  

   out 
  the 
  whole 
  range 
  of 
  living 
  forms 
  a 
  fundamental 
  similarity 
  

   in 
  the 
  manner 
  in 
  which 
  the 
  numerical 
  reduction 
  of 
  the 
  

   chromosomes 
  is 
  achieved. 
  Still, 
  it 
  will 
  also 
  be 
  apparent 
  that, 
  

   especially 
  among 
  the 
  vertebrate 
  class, 
  several 
  amphibia 
  and 
  

   mammals 
  have 
  been 
  dealt 
  with 
  by 
  various 
  authors 
  in 
  great 
  

   detail, 
  notably 
  salamander, 
  triton, 
  and 
  the 
  rat, 
  and 
  it 
  will 
  also 
  

   be 
  apparent 
  that 
  the 
  results 
  attained 
  in 
  relation 
  to 
  these 
  are 
  

   not 
  in 
  accord 
  with 
  those 
  put 
  forward 
  with 
  respect 
  to 
  insects 
  and 
  

   fishes 
  by 
  ourselves. 
  Especially 
  in 
  the 
  able 
  works 
  of 
  Flemming 
  

   and 
  Moves, 
  we 
  find 
  a 
  view 
  taken 
  with 
  respect 
  to 
  the 
  origin 
  of 
  

   the 
  diaschistic 
  (heterotype) 
  chromosomes 
  similar 
  to 
  that 
  held 
  

   by 
  many 
  botanists 
  with 
  respect 
  to 
  the 
  flowering 
  plants 
  — 
  

  

  