﻿26 
  Dr. 
  L. 
  Plate 
  on 
  Noctiluca 
  miliaria, 
  Sur. 
  

  

  and 
  longitudinal 
  grooves 
  are 
  often 
  wanting, 
  which 
  would 
  be 
  

   adverse 
  to 
  the 
  attempt 
  made 
  by 
  Biitschli 
  and 
  Pouchet 
  to 
  

   demonstrate 
  a 
  Dinoflagelliform 
  structure 
  in 
  the 
  swarmers 
  of 
  

   Noctiluca. 
  In 
  this 
  case 
  they 
  represent 
  ovate 
  or 
  oval 
  cor- 
  

   puscles, 
  somewhat 
  flattened 
  at 
  the 
  side 
  to 
  which 
  the 
  flagellum 
  

   is 
  attached. 
  The 
  animalcules 
  have 
  no 
  special 
  buccal 
  aper- 
  

   ture, 
  which 
  would 
  indicate 
  a 
  short 
  duration 
  for 
  this 
  stage 
  of 
  

   development. 
  

  

  The 
  fate 
  of 
  the 
  Noctilucce 
  which 
  have 
  lost 
  the 
  chief 
  mass 
  

   of 
  their 
  body 
  in 
  the 
  formation 
  of 
  buds 
  is 
  still 
  unknown. 
  In 
  

   some 
  animals 
  which 
  had 
  a 
  mature 
  s 
  warmer-disk 
  already 
  fur- 
  

   nished 
  with 
  cilia 
  I 
  was 
  still 
  able, 
  by 
  staining, 
  to 
  demonstrate 
  

   some 
  fragments 
  of 
  nucleus. 
  It 
  is 
  therefore 
  not 
  impossible 
  

   that 
  some 
  individuals 
  still 
  live 
  on 
  after 
  the 
  liberation 
  of 
  the 
  

   buds, 
  especially 
  as 
  here 
  and 
  there 
  considerable 
  portions 
  were 
  met 
  

   with 
  in 
  the 
  thin 
  web 
  of 
  plasma 
  which 
  always 
  remains. 
  The 
  

   Noctilucce 
  kept 
  by 
  me 
  in 
  the 
  moist 
  chamber 
  always 
  perished, 
  

   because 
  they 
  very 
  easily 
  collapse. 
  

  

  The 
  action 
  of 
  the 
  most 
  different 
  chemical 
  substances 
  and 
  

   physical 
  forces 
  upon 
  the 
  luminosity 
  of 
  Noctiluca 
  has 
  already 
  

   been 
  tried 
  by 
  a 
  great 
  number 
  of 
  naturalists. 
  They 
  all 
  arrived 
  

   at 
  the 
  result 
  that 
  the 
  luminosity 
  may 
  be 
  called 
  forth 
  by 
  any 
  

   strong 
  irritation 
  of 
  whatever 
  nature 
  so 
  long 
  as 
  the 
  air 
  is 
  not 
  

   excluded. 
  This 
  latter 
  circumstance 
  indicates 
  (as 
  the 
  light 
  is 
  

   extinguished 
  in 
  nitrogen) 
  that 
  the 
  luminosity 
  belongs 
  to 
  the 
  

   category 
  of 
  processes 
  of 
  oxidation. 
  It 
  is 
  not 
  difficult 
  to 
  

   adduce 
  some 
  further 
  observations 
  to 
  prove 
  the 
  correctness 
  of 
  

   this 
  proposition 
  ; 
  thus, 
  for 
  example, 
  the 
  luminosity 
  occurs 
  

   only 
  in 
  the 
  peripheral 
  plasma 
  of 
  the 
  body, 
  and, 
  further, 
  the 
  

   regenerative 
  states 
  of 
  Noctiluca 
  which 
  accumulate 
  at 
  the 
  

   bottom 
  of 
  a 
  vessel 
  standing 
  quietly, 
  and 
  which 
  still 
  fully 
  

   possess 
  their 
  luminous 
  power, 
  are 
  made 
  to 
  phosphoresce 
  with 
  

   much 
  more 
  difficulty 
  than 
  the 
  normal 
  individuals 
  swimming 
  

   at 
  the 
  surface, 
  because 
  the 
  latter 
  are 
  in 
  a 
  higher 
  degree 
  under 
  

   the 
  influence 
  of 
  the 
  atmospheric 
  air. 
  It 
  would 
  therefore 
  be 
  

   expected 
  that 
  saturation 
  with 
  oxygen 
  gas 
  would 
  call 
  forth 
  the 
  

   animal 
  phosphorescence 
  with 
  particular 
  intensity, 
  which 
  

   Quatrefages 
  * 
  disputes. 
  I 
  have 
  therefore 
  repeated 
  this 
  

   experiment, 
  and 
  in 
  some 
  cases 
  I 
  have 
  succeeded 
  by 
  passing 
  

   pure 
  oxygen 
  for 
  some 
  minutes 
  in 
  producing 
  a 
  dull 
  light, 
  

   which 
  was 
  still 
  uninterruptedly 
  visible 
  for 
  about 
  ten 
  minutes 
  

   after 
  the 
  evolution 
  of 
  the 
  gas. 
  That 
  the 
  experiment 
  some- 
  

   times 
  failed 
  was 
  probably 
  due 
  to 
  the 
  primitive 
  conditions 
  

   under 
  which 
  I 
  had 
  to 
  work. 
  

  

  * 
  ' 
  Ocniptes 
  Eeudus,' 
  tome 
  xxxi. 
  (1850), 
  p. 
  618. 
  

  

  