﻿tliat 
  time, 
  our 
  operations 
  were 
  iTstricted 
  almost 
  exclu- 
  

   sively 
  witliiii 
  experimental 
  limits. 
  

  

  Prof. 
  Baird, 
  1'. 
  S. 
  Commissioner 
  of 
  Fish 
  ami 
  P^isher- 
  

   ies, 
  liavin*;- 
  kindly 
  ^'ent 
  with 
  n)e 
  Prof. 
  John 
  A. 
  Ryder, 
  a 
  

   young 
  naturalist 
  of 
  thoi-ouiih 
  training 
  atid 
  expert 
  in 
  

   mioroseoj)i(' 
  work, 
  we 
  wei'e 
  a))h' 
  to 
  study 
  the 
  embryology 
  

   of 
  the 
  mackerel 
  and 
  porgy 
  in 
  a 
  xery 
  thoi-ough 
  and 
  satis- 
  

   factory 
  mannei'. 
  The 
  result 
  of 
  Prof. 
  Ryder's 
  investiga- 
  

   tions 
  will 
  1)e 
  found 
  in 
  a 
  i)aper 
  prei)ai"ed 
  1)y 
  him 
  upon 
  this 
  

   subject, 
  and 
  which 
  Avill 
  l)e 
  ])iil)lishHd 
  in 
  Prof. 
  Haird's 
  

   report 
  to 
  Congi-ess. 
  

  

  As 
  the 
  eggs 
  of 
  tlu^ 
  inackeivd. 
  uidike 
  those 
  of 
  the 
  shad, 
  

   are 
  so!uewhat 
  lighter 
  tlian 
  water 
  and 
  manifest 
  a 
  conse- 
  

   quent 
  tendency 
  to 
  lloat 
  ii})on 
  the 
  siii-face, 
  the 
  a))paratus 
  

   used 
  in 
  the 
  cidtivation 
  of 
  shad 
  cannot 
  be 
  efhciently 
  em- 
  

   ployed 
  in 
  thei]' 
  manipulation. 
  It 
  is. 
  theiefore, 
  necessary 
  

   that 
  some 
  other 
  form 
  of 
  ap])aratiis 
  should 
  be 
  devised, 
  as 
  

   that 
  used 
  in 
  the 
  shad-hatching 
  operaticms 
  is 
  so 
  con- 
  

   structed 
  that 
  a 
  ciii'rent 
  of 
  water 
  flows 
  in 
  at 
  the 
  bottom, 
  

   buoying 
  up 
  the 
  egus, 
  keeping 
  them 
  constantly 
  in 
  motion, 
  

   and 
  momentarily 
  bi'inging 
  fi-esh 
  [lai'ticles 
  of 
  water 
  in 
  

   contact 
  with 
  each 
  egg. 
  

  

  Such 
  a 
  ciiiieut. 
  eithej-in 
  the 
  conical 
  vessels 
  or 
  in 
  the 
  

   cyliudiicai 
  j)lunge 
  buckets— 
  ])oth 
  of 
  which 
  forms 
  of 
  

   api)aratLis 
  have 
  been 
  described 
  iu 
  })i'evious 
  reports 
  — 
  acts 
  

   ar/ainsf 
  the 
  gravity 
  of 
  the 
  eggs 
  of 
  the 
  shad 
  '. 
  but 
  in 
  the 
  

   case 
  of 
  those 
  of 
  the 
  mackerel, 
  and 
  of 
  all 
  others 
  that 
  have 
  

   a 
  tendency 
  to 
  lloat, 
  the 
  curi-ent 
  acts 
  wifJi 
  such 
  tendency 
  

   and 
  causes 
  the 
  eggs 
  to 
  })ile 
  in 
  masses 
  at 
  the 
  suj'face 
  of 
  

   the 
  wat« 
  r. 
  Several 
  forms 
  of 
  apparatus, 
  in 
  Avhich 
  the 
  

   direction 
  of 
  the 
  current 
  is 
  i-eversed. 
  have 
  been 
  experi- 
  

   mented 
  with, 
  and 
  are 
  found 
  to 
  act 
  most 
  satisfactorily. 
  

  

  It 
  is 
  h(»i)ed 
  that 
  dui'ing 
  the 
  next 
  season 
  the 
  work 
  (^an 
  

   be 
  c(mducte(l 
  at 
  the 
  |)ro])er 
  places 
  and 
  on 
  a 
  sutliciently 
  

   large 
  scale 
  to 
  enal)le 
  us 
  to 
  delei-miiie 
  which 
  form 
  of 
  the 
  

   vessels 
  that 
  have 
  already 
  been 
  ex]>ei'imented 
  with 
  can 
  

   be 
  opej-ated 
  witli 
  the 
  best 
  results 
  and 
  with 
  the 
  greatest 
  

  

  