﻿Studies 
  on 
  Synap>sis. 
  

  

  305 
  

  

  writer 
  proposes 
  to 
  reserve 
  the 
  consideration 
  of 
  these 
  alternatives 
  to 
  Part 
  V 
  of 
  

   this 
  series. 
  

  

  (4) 
  The 
  method 
  described 
  in 
  the 
  present 
  communication 
  of 
  carrying 
  out 
  

   the 
  fermentation 
  of 
  substances 
  in 
  the 
  presence 
  of 
  one 
  or 
  other 
  of 
  the 
  

   products 
  of 
  the 
  reactions 
  added 
  at 
  the 
  outset 
  gives 
  promise, 
  in 
  the 
  writer's 
  

   opinion, 
  of 
  lending 
  valuable 
  aid 
  in 
  the 
  solution 
  of 
  the 
  problems 
  of 
  

   fermentation. 
  

  

  In 
  conclusion, 
  I 
  wish 
  to 
  express 
  my 
  thanks 
  to 
  Prof. 
  F. 
  Gowland 
  Hopkins, 
  

   F.R.S., 
  for 
  his 
  kind 
  help 
  and 
  criticism 
  during 
  the 
  course 
  of 
  this 
  research. 
  

   I 
  would 
  also 
  like 
  to 
  acknowledge 
  my 
  debt 
  to 
  Prof. 
  Arthur 
  Harden, 
  F.R.S., 
  

   for 
  his 
  valuable 
  criticism. 
  

  

  Studies 
  on 
  Synapsis. 
  II. 
  — 
  Parallel 
  Conjugation 
  and 
  the 
  Prophase 
  

   Complex 
  in 
  Periplaneta 
  with 
  Special 
  Reference 
  to 
  the 
  Pre- 
  

   meiotic 
  Telophase. 
  

  

  By 
  Lancelot 
  T. 
  Hogben, 
  M.A., 
  B.Sc. 
  (Lecturer 
  in 
  Zoology, 
  Imperial 
  

  

  College 
  of 
  Science). 
  

  

  (Communicated 
  by 
  Prof. 
  E. 
  W. 
  MacBride, 
  F.E.S.— 
  Received 
  May 
  15, 
  1920.) 
  

  

  [Plates 
  10-12.] 
  

  

  The 
  reality 
  of 
  synapsis, 
  or 
  the 
  pairing 
  of 
  chromosomes 
  of 
  biparental 
  origin 
  

   preparatory 
  to 
  their 
  segregation 
  during 
  the 
  maturation 
  divisions 
  of 
  the 
  germ 
  

   cells, 
  provides 
  at 
  present 
  the 
  most 
  fruitful 
  basis 
  for 
  any 
  attempt 
  to 
  correlate 
  

   genetio 
  phenomena 
  with 
  cell 
  structure 
  ; 
  and 
  it 
  rests 
  upon 
  data 
  derived 
  from 
  

   sources 
  that 
  are 
  strictly 
  independent 
  of 
  the 
  behaviour 
  of 
  the 
  chromosomes 
  

   during 
  the 
  remarkable 
  series 
  of 
  events 
  intercalated 
  in 
  the 
  prophase 
  of 
  the 
  

   heterotype 
  mitosis. 
  It 
  is, 
  however, 
  only 
  possible 
  to 
  gain 
  a 
  knowledge 
  

   regarding 
  the 
  manner 
  in 
  which 
  homologous 
  chromosomes 
  are 
  brought 
  into 
  

   association 
  with 
  one 
  another 
  by 
  a 
  study 
  of 
  the 
  meiotic 
  phase 
  itself. 
  To 
  the 
  

   earlier 
  workers 
  the 
  reality 
  of 
  synapsis 
  was 
  the 
  all-absorbing 
  problem, 
  while 
  

   the 
  means 
  by 
  which 
  it 
  is 
  effected 
  formed 
  a 
  secondary 
  consideration. 
  It 
  is 
  

   possible, 
  given 
  the 
  conjugation 
  of 
  chromosomes 
  derived 
  from 
  alternate 
  parents, 
  

   to 
  explain 
  the 
  independent 
  segregation 
  of 
  allelomorphic 
  pairs 
  on 
  the 
  

   assumption 
  that 
  their 
  material 
  basis 
  resides 
  in 
  different 
  bivalents; 
  while 
  

  

  