﻿LOBSTER 
  AND 
  CLAM 
  INVESTIGATIONS. 
  181 
  

  

  Synedra 
  gallioni 
  Ehrenberg. 
  

  

  Synedraaffinis 
  Kiitzing. 
  

  

  Tabellaria 
  (Striatella) 
  unipuiictata 
  Agardh. 
  

  

  Navicula 
  sp. 
  

  

  Cocconeis 
  scutelluni 
  Ehrenberg. 
  

  

  Melosira 
  sp. 
  

  

  Melosira 
  nummuloides 
  Agardh. 
  

  

  Cocconeis 
  sp. 
  

  

  It 
  seems 
  as 
  if 
  in 
  these 
  bags 
  we 
  had 
  an 
  ideal 
  method 
  of 
  growing 
  

   diatoms 
  in 
  large 
  numbers 
  under 
  the 
  most 
  favorable 
  conditions 
  for 
  dis- 
  

   tributing 
  them 
  to 
  the 
  fry. 
  The 
  circulation 
  of 
  water 
  is 
  continually 
  

   throwing 
  the 
  fry 
  against 
  the 
  sides 
  of 
  the 
  bags, 
  and 
  if 
  these 
  bags 
  are 
  

   foul 
  with 
  a 
  growth 
  of 
  diatoms, 
  the 
  fry 
  will 
  become 
  foul 
  almost 
  as 
  soon 
  

   as 
  they 
  are 
  placed 
  in 
  the 
  bags. 
  

  

  PRESENCE 
  OF 
  DIATOMS 
  AT 
  OTHER 
  LOCALITIES. 
  

  

  At 
  Woods 
  Hole, 
  as 
  we 
  have 
  already 
  seen, 
  the 
  species 
  of 
  diatoms 
  

   that 
  trouble 
  the 
  lobster 
  fry 
  are 
  distributed 
  quite 
  generally 
  in 
  the 
  water 
  

   and 
  on 
  all 
  submerged 
  objects. 
  It 
  was 
  desirable 
  to 
  determine 
  whether 
  

   the 
  same 
  conditions 
  exist 
  at 
  other 
  places 
  along 
  the 
  coast, 
  and 
  examina- 
  

   tions 
  were 
  made 
  with 
  this 
  in 
  view. 
  

  

  Conditions 
  at 
  Gloucester^ 
  Mass. 
  — 
  In 
  the 
  hatching 
  jars 
  at 
  Gloucester, 
  

   on 
  the 
  inside 
  of 
  the 
  glass 
  and 
  on 
  the 
  tubes, 
  June 
  21, 
  1902, 
  there 
  were 
  

   found 
  a 
  very 
  few 
  Licnvyphora 
  tincta^ 
  along 
  with 
  several 
  other 
  species 
  

   {('o.scinodiscus 
  sp., 
  Cocconeis 
  sp., 
  Navicula 
  sp., 
  Rhahdonenia 
  arcua- 
  

   taiii). 
  In 
  no 
  case 
  were 
  diatoms 
  as 
  abundant 
  as 
  in 
  the 
  same 
  places 
  in 
  the 
  

   Woods 
  Hole 
  jars, 
  however. 
  In 
  fact, 
  considerable 
  search 
  was 
  required 
  

   to 
  find 
  any, 
  and 
  none 
  of 
  the 
  fry 
  taken 
  from 
  the 
  hatching 
  jars 
  at 
  

   Gloucester 
  showed 
  a 
  single 
  diatom. 
  They 
  were 
  perfectly 
  clean, 
  in 
  

   decided 
  contrast 
  to 
  the 
  condition 
  of 
  the 
  fry 
  in 
  the 
  jars 
  at 
  Woods 
  Hole. 
  

  

  Conditions 
  at 
  Wicliford., 
  R. 
  I. 
  — 
  Experiments 
  in 
  lobster 
  culture 
  have 
  

   been 
  carried 
  on 
  for 
  the 
  past 
  three 
  summers 
  (1900, 
  1901, 
  1902) 
  at 
  

   Wickford, 
  R. 
  I., 
  at 
  the 
  floating 
  laboratory 
  and 
  hatchery 
  of 
  the 
  Rhode 
  

   Island 
  Fish 
  Commission. 
  The 
  flrst 
  year 
  the 
  fry 
  were 
  confined 
  in 
  large 
  

   square 
  bags 
  made 
  of 
  scrim, 
  fastened 
  to 
  a 
  float 
  and 
  weighted 
  at 
  the 
  

   lower 
  corners. 
  A 
  few 
  unsuccessful 
  experiments 
  were 
  made 
  with 
  cars. 
  

   One 
  experiment 
  was 
  tried 
  in 
  which 
  the 
  water 
  in 
  the 
  bags 
  was 
  contin- 
  

   ually 
  stirred 
  with 
  an 
  oar 
  for 
  six 
  days. 
  Doctor 
  Mead 
  states 
  in 
  the 
  

   Report 
  of 
  the 
  Rhode 
  Island 
  Fish 
  Commission 
  for 
  1901 
  (page 
  71) 
  that 
  

   "a 
  larger 
  proportion 
  of 
  fry 
  was 
  obtained 
  from 
  this 
  experiment 
  than 
  

   from 
  any 
  other 
  ever 
  tried 
  at 
  Wickford, 
  Woods 
  Hole, 
  or 
  elsewhere, 
  and 
  

   also 
  that 
  one 
  of 
  the 
  most 
  encouraging 
  results 
  of 
  the 
  experiment 
  was 
  the 
  

   clean 
  and 
  healthy 
  appearance 
  of 
  the 
  fry 
  at 
  all 
  stages. 
  The 
  continual 
  

   stirring 
  prevented 
  the 
  accumulation 
  of 
  the 
  parasites 
  found 
  on 
  the 
  

   bodies 
  of 
  nearly 
  all 
  specimens 
  in 
  the 
  other 
  lots." 
  This 
  seems 
  to 
  indi- 
  

  

  