﻿94 
  REPOET 
  OF 
  COMMISSIONER 
  OF 
  FISH 
  AND 
  FISHERIES. 
  

  

  who 
  visited 
  the 
  station 
  in 
  December 
  and 
  made 
  a 
  thorough 
  examination 
  

   of 
  the 
  water 
  supply, 
  pipes, 
  pumps, 
  tanks, 
  aquarium, 
  and 
  fishes. 
  

  

  Under 
  date 
  of 
  December 
  1, 
  the 
  superintendent 
  had 
  reported 
  that 
  

   fish 
  could 
  not 
  be 
  kept 
  alive 
  in 
  the 
  aquaria 
  more 
  than 
  forty-eight 
  hours, 
  

   notwithstanding 
  every 
  possible 
  attention 
  and 
  care. 
  This 
  accorded 
  with 
  

   the 
  experience 
  during 
  the 
  previous 
  summer 
  when, 
  on 
  account 
  of 
  the 
  

   workers 
  in 
  the 
  laboratory 
  and 
  the 
  large 
  numbers 
  of 
  visitors 
  at 
  the 
  

   station, 
  an 
  effort 
  was 
  made 
  to 
  keep 
  the 
  aquaria 
  well 
  stocked. 
  These 
  

   aquaria 
  are 
  supplied 
  with 
  sea 
  water 
  from 
  the 
  same 
  tanks 
  that 
  feed 
  the 
  

   hatchery, 
  the 
  tanks 
  being 
  kept 
  full 
  by 
  two 
  steam 
  pumps 
  which 
  carry 
  

   the 
  water 
  from 
  the 
  basin 
  or 
  pool 
  in 
  front 
  of 
  the 
  hatchery. 
  

  

  Specimens 
  of 
  the 
  common 
  winter 
  fishes 
  available 
  for 
  the 
  aquaria 
  

   (white 
  perch, 
  tautog, 
  tomcod, 
  sculpins, 
  and 
  flat-fish), 
  caught 
  in 
  a 
  fyke 
  

   net 
  in 
  the 
  harbor 
  and 
  immediately 
  transferred 
  to 
  the 
  aquaria, 
  in 
  about 
  

   three 
  minutes 
  became 
  covered 
  with 
  minute 
  bubbles 
  of 
  gas. 
  These 
  

   bubbles 
  increased 
  in 
  number 
  and, 
  after 
  ten 
  minutes, 
  thickly 
  covered 
  

   the 
  fish, 
  giving 
  to 
  dark 
  species 
  like 
  the 
  tomcod 
  a 
  silvery 
  appearance. 
  

   When 
  a 
  fish 
  was 
  removed 
  from 
  the 
  water 
  a 
  moment 
  the 
  bubbles 
  imme- 
  

   diately 
  dissipated, 
  but 
  were 
  renewed, 
  as 
  before, 
  when 
  it 
  was 
  returned 
  

   to 
  the 
  water. 
  They 
  constantly 
  escaped 
  in 
  small 
  numbers 
  from 
  the 
  

   body 
  and 
  rose 
  to 
  the 
  surface 
  of 
  the 
  water, 
  while 
  a 
  sudden 
  movement 
  

   on 
  the 
  part 
  of 
  the 
  fish 
  released 
  a 
  cloud 
  of 
  thousands 
  of 
  bubbles. 
  After 
  

   a 
  short 
  time, 
  however, 
  it 
  was 
  again 
  covered 
  with 
  them, 
  «o 
  that 
  it 
  was 
  

   seldom 
  without 
  more 
  or 
  less 
  of 
  these 
  gas 
  bubbles 
  clinging 
  to 
  any 
  or 
  

   all 
  parts 
  of 
  the 
  body 
  and 
  fins. 
  After 
  a 
  period 
  varying 
  from 
  three 
  

   hours 
  to 
  several 
  days, 
  the 
  fish 
  died, 
  usually 
  with 
  spasmodic 
  convul- 
  

   sions. 
  Of 
  a 
  lot 
  of 
  about 
  100 
  specimens, 
  70 
  per 
  cent 
  were 
  dead 
  after 
  

   forty-eight 
  hours, 
  though 
  a 
  few 
  flat-fish 
  survived 
  four 
  days. 
  

  

  Dissection 
  of 
  the 
  bodies 
  showed 
  a 
  remarkable 
  condition. 
  The 
  blood 
  

   vascular 
  system 
  contained 
  notable 
  quantities 
  of 
  gas. 
  In 
  the 
  mildest 
  

   degree 
  this 
  appeared 
  as 
  large 
  bubbles 
  here 
  and 
  there 
  in 
  the 
  larger 
  

   vessels, 
  which 
  still 
  contained 
  blood. 
  In 
  the 
  extreme 
  cases 
  the 
  heart 
  

   itself 
  contained 
  gas 
  to 
  the 
  exclusion 
  of 
  the 
  blood. 
  The 
  bulbus 
  of 
  the 
  

   heart 
  was 
  often 
  greatly 
  distended 
  — 
  even 
  to 
  several 
  times 
  its 
  normal 
  

   bulk 
  — 
  its 
  walls 
  stretched 
  to 
  an 
  attenuated 
  thinness, 
  tense 
  and 
  firm 
  with 
  

   the 
  pressure 
  of 
  the 
  contained 
  gas 
  to 
  the 
  entire 
  exclusion 
  of 
  the 
  blood, 
  

   the 
  whole 
  resembling 
  the 
  air 
  bladder 
  of 
  a 
  small 
  fish. 
  The 
  auricle 
  

   sometimes 
  continued 
  beating, 
  but 
  without 
  propelling 
  any 
  blood. 
  

   Often 
  the 
  thick 
  wall 
  of 
  the 
  ventricle 
  was 
  emphysematous. 
  The 
  vessel 
  

   from 
  the 
  heart 
  to 
  the 
  gills 
  was 
  empty 
  of 
  blood, 
  and 
  in 
  the 
  gills 
  was 
  

   found 
  perhaps 
  the 
  most 
  constant 
  and 
  significant 
  lesion. 
  The 
  main 
  vessel 
  

   of 
  the 
  gill 
  filament 
  was 
  filled 
  with 
  gas, 
  which 
  was 
  often 
  seen 
  just 
  

   entering 
  the 
  capillaries 
  that 
  branch 
  from 
  this 
  vessel. 
  It 
  seldom 
  filled 
  

   these 
  capillaries, 
  however. 
  These 
  gas 
  plugs 
  of 
  the 
  gill 
  filaments 
  were 
  

   usually 
  present, 
  even 
  when 
  the 
  evidences 
  of 
  gas 
  within 
  the 
  body 
  were 
  

  

  