﻿70 
  

  

  be 
  relied 
  upon 
  and 
  assigned 
  a 
  greater 
  value 
  than 
  those 
  

   of 
  most 
  amateurs. 
  

  

  THE 
  AKTIFK 
  lAL 
  I 
  MPUE<;.\ATI()N 
  OF 
  THE 
  VAiii. 
  

  

  Two 
  ripe 
  males 
  were 
  selected, 
  the 
  spermatozoa 
  from 
  

   which 
  was 
  very 
  active, 
  and 
  the 
  visceral 
  mass 
  was 
  cut 
  

   out 
  ; 
  all 
  parts 
  of 
  the 
  digestive 
  organs 
  were 
  then 
  removed, 
  

   leaving 
  the 
  generative 
  products 
  in 
  the 
  saucer. 
  The 
  lat- 
  

   ter 
  were 
  then 
  cliopped 
  up 
  as 
  tinely 
  as 
  possible 
  and 
  mixed 
  

   with 
  salt 
  water, 
  and 
  the 
  fragments 
  of 
  the 
  digestive 
  or- 
  

   gans, 
  mantles 
  nnd 
  gills 
  carefully 
  washed 
  out. 
  and 
  this 
  

   process 
  was 
  rei)eated 
  several 
  times 
  until 
  the 
  male 
  Huid 
  

   was 
  free 
  from 
  nil 
  deleterious 
  matter. 
  Two 
  female 
  oys- 
  

   ters 
  were 
  then 
  treated 
  in 
  a 
  like 
  manner, 
  and 
  finally 
  both 
  

   male 
  and 
  female 
  fluids 
  \\ 
  ere 
  mixed 
  thoroughly 
  in 
  a 
  glass 
  

   holding 
  one 
  half 
  pint 
  of 
  clean 
  salt 
  water. 
  The 
  fertiliza- 
  

   tion 
  was 
  accomp»lished 
  at 
  8.!K^i 
  P. 
  Vi. 
  on 
  June 
  6th. 
  The 
  

   following 
  are 
  the 
  noted 
  times 
  of 
  rhe 
  principle 
  changes 
  

   during 
  the 
  process 
  of 
  segjnentation 
  and 
  subsequent 
  de- 
  

   velopment 
  : 
  

  

  8.1'2 
  P. 
  M. 
  The 
  eggs 
  were 
  irregular 
  in 
  shape 
  and 
  cov- 
  

   ered 
  wifh 
  spermatozoa 
  — 
  gei-iuinative 
  vesicle 
  plainly 
  vis- 
  

   il^le 
  — 
  ai)pearance 
  exactly 
  as 
  figured 
  by 
  Brooks. 
  (Report 
  

   Com. 
  Fisheries, 
  Maryland— 
  PL 
  VIII— 
  Fig. 
  51. 
  

  

  8.32 
  P. 
  M. 
  Germinative 
  vesicle 
  had 
  disappeared 
  and 
  

   eggs 
  nearly 
  sinular 
  to 
  Brook's 
  fig. 
  52, 
  though 
  not 
  so 
  reg- 
  

   ular 
  in 
  outline. 
  

  

  The 
  wnter 
  was 
  now 
  siphoned 
  off 
  and 
  the 
  glass 
  half 
  

   filled 
  with 
  fresh 
  sea- 
  water. 
  

  

  10.08 
  P. 
  M. 
  One 
  hour 
  and 
  fifty-three 
  ndnutes 
  after 
  

   fertilization, 
  the 
  eggs 
  had 
  become 
  elongated, 
  and 
  the 
  

   polar 
  globule 
  was 
  easily 
  observed. 
  In 
  a 
  few 
  eggs 
  the 
  

   separation 
  of 
  the 
  micromeres 
  and 
  macromeres 
  could 
  be 
  

   distinguished. 
  The 
  ap[)earance 
  of 
  the 
  eggs 
  was 
  as 
  is 
  

   shown 
  in 
  Brook's 
  figs. 
  2, 
  3, 
  4 
  and 
  5. 
  the 
  larger 
  number 
  

   resembling 
  figs. 
  2 
  and 
  8. 
  

  

  At 
  11.10, 
  about 
  three 
  hours 
  after 
  fertilization, 
  all 
  the 
  

  

  