﻿10 
  Merriman: 
  Conjugation 
  of 
  Spirogyr^v 
  ternata 
  

  

  differences 
  in 
  the 
  form 
  of 
  the 
  conjugating 
  tubes 
  and 
  cell 
  contents 
  

   as 
  to 
  suggest 
  the 
  problems 
  investigated 
  in 
  this 
  paper. 
  

  

  A 
  sinuosity 
  is 
  to 
  be 
  noted 
  in 
  the 
  filaments 
  in 
  both 
  vegetative 
  

   and 
  fruiting 
  states, 
  associated 
  with 
  a 
  certain 
  degree 
  of 
  motility. 
  

   It 
  is 
  questionable 
  which 
  is 
  the 
  greater 
  contributory 
  factor 
  to 
  

  

  J 
  

  

  these 
  movements, 
  inequalities 
  of 
  growth 
  or 
  inequalities 
  in 
  the 
  

   turgor 
  of 
  the 
  cells, 
  increased 
  possibly 
  by 
  the 
  mucilaginous 
  layer 
  

   on 
  the 
  cell 
  wall. 
  When 
  in 
  a 
  state 
  of 
  conjugation 
  the 
  short 
  portions 
  

   of 
  threads 
  of 
  S. 
  maxima 
  which 
  are 
  contained 
  in 
  the 
  field 
  of 
  view 
  

   under 
  the 
  low 
  power 
  of 
  the 
  compound 
  microscope 
  can 
  be 
  seen 
  to 
  

   be 
  straight 
  and 
  to 
  consist 
  of 
  large 
  cells 
  joined 
  by 
  small 
  and 
  narrow 
  

   tubes. 
  The 
  fertile 
  cells 
  of 
  this 
  species 
  are 
  always 
  unswoUen. 
  

   In 
  5. 
  ternata 
  straight 
  threads 
  are 
  rarely 
  to 
  be 
  seen 
  and 
  then 
  only 
  

   in 
  the 
  earliest 
  stages 
  of 
  conjugation, 
  while 
  a 
  marked 
  feature 
  of 
  

   the 
  species 
  is 
  found 
  in 
  the 
  swollen 
  9 
  cells. 
  The 
  swelling 
  often 
  

   affects 
  the 
  cells 
  throughout 
  their 
  entire 
  length 
  and 
  sometimes 
  

   increases 
  their 
  volume 
  twofold, 
  if 
  the 
  extensions 
  of 
  the 
  conjugating 
  

   tubes 
  are 
  taken 
  into 
  account. 
  The 
  filaments 
  of 
  S. 
  ternata 
  not 
  

  

  sinuosity 
  

  

  two 
  

  

  in 
  spite 
  of 
  the 
  fact 
  that 
  there 
  are 
  certain 
  irregularities 
  in 
  the 
  number 
  

   of 
  the 
  cells. 
  A 
  comparison 
  of 
  numerous 
  threads, 
  whether 
  lying 
  

   in 
  water 
  or 
  preserving 
  fluids, 
  showed 
  that 
  the 
  filaments 
  always 
  

   assumed 
  curves 
  which 
  varied 
  from 
  those 
  slightly 
  bent 
  to 
  those 
  

   forming 
  semicircles. 
  Further 
  examination 
  disclosed 
  the 
  fact 
  

   that 
  the 
  9 
  threads 
  were 
  invariably 
  lying 
  on 
  the 
  outer 
  side 
  of 
  

   the 
  curve, 
  unless 
  displaced 
  or 
  twisted 
  in 
  mounting. 
  Often, 
  in 
  the 
  

   water, 
  the 
  conjugating 
  threads 
  would 
  naturally 
  tw^ist, 
  but 
  in 
  so 
  

   doing 
  the 
  9 
  thread, 
  after 
  a 
  turn 
  of 
  a 
  few 
  cells, 
  would 
  again 
  be 
  

   found 
  lying 
  outside 
  the 
  cf 
  filament. 
  . 
  • 
  

  

  r 
  

  

  S. 
  ternata 
  is 
  an 
  example 
  of 
  ty-pical 
  scalariform 
  conjugation, 
  

   for 
  in 
  the 
  hundreds 
  of 
  filaments 
  studied 
  the 
  movement 
  in 
  the 
  

   conjugating 
  cells 
  was 
  always 
  found 
  to 
  be 
  in 
  one 
  direction. 
  

   It 
  would 
  be 
  of 
  interest 
  to 
  discover 
  cases 
  of 
  cross 
  conjugation, 
  

   such 
  as 
  those 
  reported 
  by 
  Cunningham 
  (3) 
  in 
  a 
  smaller 
  species 
  of 
  

   Spirogyra. 
  If 
  forms 
  of 
  cross 
  conjugation 
  should 
  be 
  found, 
  where 
  

   regular 
  alternating 
  movements 
  of 
  contents 
  take 
  place, 
  cells 
  with 
  

   straight 
  outlines 
  would 
  seem 
  probable, 
  while 
  if 
  threads 
  were 
  found 
  

  

  