﻿514 
  REPORT 
  OF 
  COMMISSIONER 
  OF 
  FISH 
  AND 
  FISHERIES. 
  [26] 
  

  

  The 
  blood 
  becomes 
  red 
  in 
  color 
  before 
  the 
  embryo 
  leaves 
  the 
  egg. 
  The 
  

   vascular 
  system 
  is 
  better 
  developed 
  in 
  this 
  species 
  at 
  the 
  time 
  of 
  hatch- 
  

   ing 
  than 
  in 
  any 
  other 
  known 
  to 
  me, 
  as 
  well-defined 
  vascular 
  loops 
  

   already 
  exist 
  in 
  the 
  dorsal 
  and 
  ventral 
  median 
  fin-folds. 
  The 
  branchial 
  

   vessels, 
  arches, 
  and 
  opercula 
  are 
  also 
  in 
  an 
  advanced 
  condition 
  of 
  de- 
  

   velopment 
  at 
  this 
  period, 
  unusually 
  so 
  when 
  compared 
  with 
  the 
  embryos 
  

   of 
  most 
  other 
  forms 
  at 
  the 
  same 
  stage. 
  

  

  Lateral 
  sensory 
  or 
  segmental 
  sense 
  organs 
  are 
  developed 
  on 
  the 
  

   skin 
  at 
  the 
  time 
  of 
  hatching. 
  If 
  the 
  youug 
  fish 
  is 
  allowed 
  to 
  assume 
  

   its 
  normal 
  position 
  in 
  a 
  live-box, 
  and 
  the 
  microscope 
  applied, 
  looking 
  

   down 
  past 
  the 
  sides 
  of 
  the 
  body 
  from 
  above, 
  certain 
  thickenings 
  of 
  the 
  

   epiblast 
  or 
  integument 
  will 
  be 
  noticed. 
  These 
  thickenings 
  are 
  sur- 
  

   mounted 
  by 
  transparent 
  cells 
  which 
  project 
  freely 
  for 
  a 
  little 
  distance 
  

   from 
  the 
  general 
  level 
  of 
  the 
  surface. 
  The 
  outer 
  ends 
  of 
  these 
  cells, 
  ten 
  

   or 
  twelve 
  in 
  number, 
  are 
  somewhat 
  separated 
  from 
  one 
  another, 
  and 
  

   have 
  blunt 
  truncated 
  tips 
  which 
  are 
  not 
  surmounted 
  with 
  sensory 
  hairs 
  

   or 
  filaments. 
  The 
  segmental 
  sense 
  organs 
  of 
  the 
  lateral 
  line 
  in 
  the 
  

   young 
  stickleback, 
  therefore, 
  differ 
  very 
  widely 
  from 
  those 
  of 
  the 
  cod. 
  

   Fig. 
  27 
  represents 
  an 
  older 
  larva 
  in 
  which 
  the 
  lower 
  lobe 
  of 
  the 
  tail 
  is 
  

   beginning 
  to 
  develop. 
  

  

  THE 
  SPINNING 
  HABITS 
  OF 
  THE 
  ADULT 
  MALE 
  DURING 
  THE 
  BREED 
  

  

  ING 
  SEASON. 
  

  

  It 
  has 
  been 
  known 
  for 
  a 
  long 
  time 
  that 
  the 
  males 
  of 
  the 
  different 
  spe- 
  

   cies 
  of 
  sticklebacks 
  build 
  a 
  nest 
  in 
  which 
  they 
  place 
  the 
  eggs 
  laid 
  by 
  the 
  

   females. 
  The 
  water 
  is 
  continually 
  forced 
  through 
  the 
  mass 
  of 
  eggs 
  by 
  

   the 
  male 
  fish, 
  which 
  moves 
  his 
  fins 
  for 
  the 
  purpose, 
  and 
  also 
  draws 
  or 
  

   pumps 
  the 
  water 
  through 
  the 
  clump 
  of 
  eggs 
  with 
  his 
  mouth 
  in 
  execut- 
  

   ing 
  the 
  movements 
  of 
  the 
  jaws, 
  gills, 
  and 
  opercula 
  incident 
  to 
  respira- 
  

   tion. 
  Just 
  how 
  the 
  nest 
  was 
  built, 
  however, 
  never 
  seems 
  to 
  have 
  been 
  

   observed 
  until 
  about 
  1879 
  or 
  1880, 
  when 
  Mr. 
  W. 
  P. 
  Seal 
  noticed 
  that 
  

   the 
  nest 
  was 
  built 
  of 
  threads 
  drawn 
  out 
  through 
  an 
  opening 
  near 
  the 
  

   vent 
  of 
  the 
  male, 
  and 
  that 
  the 
  latter 
  wound 
  these 
  threads 
  round 
  the 
  clus- 
  

   ter 
  of 
  weeds 
  chosen 
  to 
  support 
  the 
  nest 
  in 
  a 
  wonderfully 
  intelligent 
  

   manner. 
  Specimens 
  with 
  which 
  this 
  gentleman 
  kindly 
  supplied 
  me 
  in 
  

   1881, 
  upon 
  dissection, 
  showed 
  that 
  there 
  was 
  present, 
  lying 
  on 
  the 
  right 
  

   side 
  of 
  the 
  rectum, 
  a 
  large 
  sack 
  filled 
  with 
  a 
  viscid 
  secretion, 
  and 
  that 
  

   this 
  was 
  the 
  source 
  of 
  the 
  material 
  of 
  which 
  the 
  threads 
  were 
  formed. 
  

   These 
  observations, 
  which 
  were 
  published 
  four 
  years 
  since, 
  have 
  appar- 
  

   ently 
  been 
  overlooked 
  by 
  Mobius, 
  42 
  avIio 
  has 
  recently 
  given 
  an 
  account 
  

   of 
  his 
  observations 
  on 
  the 
  spinning 
  organs 
  of 
  Spinachia 
  vulgaris 
  Flein., 
  

   though 
  his 
  observations 
  are 
  far 
  more 
  complete 
  than 
  were 
  my 
  own. 
  

  

  On 
  the 
  habits 
  of 
  the 
  male 
  Apeltes, 
  I 
  wrote 
  as 
  follows 
  in 
  1881: 
  "The 
  

   male 
  binds 
  the 
  nest 
  together 
  by 
  means 
  of 
  a 
  compound 
  thread 
  which 
  he 
  

  

  42 
  K. 
  Mobius. 
  Ueber 
  die 
  Eigeuschaften 
  uud 
  deu 
  Ursprung 
  der 
  Schleimfaden 
  des 
  See- 
  

   sticMingsnestes. 
  Arch. 
  f. 
  mikr. 
  Anat., 
  xxv, 
  1885, 
  1 
  plate. 
  Also, 
  Die 
  Niere 
  des 
  mann- 
  

   liclien 
  Seestichliugs, 
  eine 
  Spiundriise. 
  Biolog. 
  Ceiitralbl., 
  v, 
  1886, 
  pp. 
  647-648. 
  

  

  