﻿LOBSTER 
  AND 
  OLAM 
  INVESTIGATIONS. 
  169 
  

  

  From 
  Table 
  IV 
  it 
  will 
  be 
  seen 
  that 
  the 
  results 
  of 
  the 
  experiments 
  

   varied 
  g-reatly 
  daring 
  the 
  season. 
  First 
  was 
  a 
  period 
  of 
  partial 
  fail- 
  

   ure, 
  followed 
  about 
  the 
  middle 
  of 
  the 
  season 
  b}^ 
  one 
  of 
  success, 
  while 
  

   practicalh^ 
  all 
  the 
  experiments 
  from 
  June 
  25 
  to 
  the 
  close 
  were 
  total 
  

   failures. 
  It 
  should 
  not 
  be 
  forgotten, 
  however, 
  that 
  in 
  the 
  early 
  experi- 
  

   ments 
  at 
  Woods 
  Hole 
  it 
  was 
  unusual 
  to 
  rear 
  more 
  than 
  1 
  per 
  cent 
  of 
  a 
  

   given 
  number 
  of 
  lobster 
  fr}^ 
  to 
  the 
  fourth 
  stage, 
  no 
  matter 
  what 
  kind 
  

   of 
  inclosure 
  was 
  used 
  or 
  where 
  the 
  experiment 
  was 
  located. 
  In 
  the 
  

   experiments 
  of 
  1902, 
  10, 
  12, 
  and 
  even 
  20 
  per 
  cent 
  of 
  the 
  original 
  num- 
  

   ber 
  of 
  fry 
  were 
  successfully 
  carried 
  to 
  the 
  lobsterling 
  stage, 
  and 
  these 
  

   figures 
  are 
  based 
  on 
  actually 
  counted 
  fry, 
  not 
  on 
  estimates. 
  

  

  One 
  cause 
  attending 
  at 
  least 
  the 
  early 
  unsatisfactory 
  results 
  of 
  these 
  

   experiments 
  was 
  the 
  lack 
  of 
  sufficient 
  food. 
  Great 
  difficulty 
  was 
  

   experienced 
  in 
  finding 
  a 
  food 
  which 
  the 
  fry 
  would 
  eat 
  and 
  wdiich 
  could 
  

   be 
  obtained 
  in 
  sufficient 
  quantities 
  to 
  make 
  it 
  practicable. 
  Until 
  the 
  

   solution 
  of 
  this 
  problem 
  (which 
  is 
  discussed 
  fully 
  elsewhere), 
  the 
  young 
  

   lobsters 
  were 
  poorly 
  nourished, 
  growth 
  was 
  retarded, 
  parasites 
  flour- 
  

   ished; 
  and 
  these 
  conditions 
  were 
  aggravated 
  by 
  moving 
  the 
  plant 
  from 
  

   place 
  to 
  place. 
  For 
  two 
  or 
  three 
  weeks 
  after 
  the 
  time 
  the 
  food 
  supply 
  

   became 
  plentiful, 
  the 
  fry 
  in 
  all 
  the 
  experiments 
  grew 
  rapidly 
  and 
  were 
  

   strong 
  and 
  healthy. 
  In 
  one 
  week 
  more 
  than 
  2,000 
  lobsterlings 
  were 
  

   taken 
  from 
  six 
  bags, 
  one 
  bag 
  alone 
  yielding 
  725. 
  

  

  The 
  experiments 
  of 
  the 
  latter 
  part 
  of 
  the 
  season, 
  however, 
  were 
  

   most 
  disappointing. 
  Awnings 
  had 
  been 
  stretched 
  over 
  the 
  bags, 
  and 
  

   it 
  w^as 
  found 
  that 
  b}^ 
  excluding 
  the 
  direct 
  sunlight 
  the 
  diatoms 
  were 
  

   greatly 
  reduced 
  in 
  numbers, 
  but 
  even 
  the 
  disappearance 
  of 
  this 
  enemy 
  

   apparently 
  had 
  no 
  effect 
  in 
  decreasing 
  the 
  mortality. 
  The 
  develop- 
  

   ment 
  of 
  the 
  fry 
  was 
  different 
  from 
  that 
  heretofore 
  observed. 
  They 
  

   grew 
  well, 
  and 
  reached 
  the 
  third 
  stage 
  in 
  an 
  apparently 
  strong 
  and 
  

   healthy 
  condition 
  ; 
  they 
  were 
  free 
  of 
  diatoms, 
  were 
  vigorous 
  and 
  active, 
  

   and 
  fed 
  well; 
  but 
  within 
  a 
  day 
  or 
  two 
  all 
  had 
  died, 
  and 
  the 
  cause 
  of 
  

   this 
  mortality 
  could 
  not 
  be 
  determined. 
  It 
  was 
  noticed 
  that 
  man}^ 
  of 
  

   the 
  dead 
  lobsters, 
  and 
  occasionally 
  living 
  ones, 
  had 
  white 
  spots 
  on 
  their 
  

   bodies. 
  Professor 
  Gorham, 
  who 
  was 
  studying 
  the 
  diatoms, 
  examined 
  

   many 
  of 
  these 
  spots 
  and 
  found 
  them 
  to 
  be 
  colonies 
  of 
  a 
  mold 
  which 
  had 
  

   ramified 
  through 
  and 
  through 
  the 
  tissues. 
  Whether 
  this 
  was 
  the 
  pri- 
  

   mary 
  cause 
  of 
  death 
  Professor 
  Gorham 
  was 
  unable 
  to 
  determine. 
  After 
  

   its 
  appearance, 
  however, 
  it 
  was 
  almost 
  impossible 
  to 
  raise 
  a 
  single 
  lob- 
  

   sterling. 
  Frequent 
  changing 
  of 
  the 
  bags, 
  exclusion 
  or 
  presence 
  of 
  

   direct 
  sunlight, 
  or 
  changes 
  in 
  quantity 
  and 
  kind 
  of 
  food 
  made 
  no 
  

   apparent 
  difference. 
  

  

  That 
  bag 
  experiments 
  like 
  those 
  of 
  1901 
  would 
  not 
  have 
  been 
  more 
  

   successful 
  in 
  1902, 
  was 
  proved 
  by 
  experiment 
  before 
  the 
  completion 
  

   of 
  the 
  rearing 
  plant. 
  Fry 
  were 
  placed 
  in 
  one 
  of 
  the 
  cylindrical 
  bags 
  

   and 
  occasionally 
  stirred. 
  They 
  were 
  regularly 
  fed 
  and 
  had 
  excellent 
  

  

  