﻿[15] 
  

  

  DEVELOPMENT 
  OF 
  OSSEOUS 
  FISHES. 
  

  

  503 
  

  

  Agassiz 
  really 
  were 
  of 
  the 
  same 
  species, 
  that 
  the 
  development 
  of 
  its 
  ova 
  

   occurs 
  in 
  fresh 
  as 
  well 
  as 
  in 
  sea- 
  water. 
  The 
  larva? 
  captured 
  and 
  figured 
  

   by 
  Agassiz, 
  32 
  though 
  it 
  is 
  nowhere 
  specifically 
  im- 
  

   plied 
  that 
  these 
  young 
  fishes 
  were 
  not 
  taken 
  from 
  

   fresh 
  water, 
  were 
  probably 
  captured 
  in 
  salt 
  water, 
  

   as 
  were 
  most 
  of 
  the 
  forms 
  figured 
  by 
  him. 
  Speci- 
  

   mens 
  in 
  my 
  possession 
  of 
  young 
  striped 
  bass 
  one 
  

   day 
  old, 
  hatched 
  from 
  ova 
  fertilized 
  with 
  the 
  milt 
  

   of 
  the 
  white 
  perch, 
  Eoccus 
  americanus 
  (Gmel.) 
  J. 
  

   and 
  G., 
  measure 
  3.5 
  mm 
  in 
  length, 
  or 
  the 
  same 
  as 
  

   the 
  youngest 
  stage 
  figured 
  by 
  Agassiz, 
  but 
  the 
  

   jaws 
  and 
  mouth 
  are 
  not 
  nearly 
  as 
  well 
  develoj)ed 
  

   and 
  the 
  intestine 
  is 
  relatively 
  much 
  longer, 
  nor 
  

   are 
  the 
  median 
  fin-folds 
  as 
  wide. 
  The 
  intestine 
  

   also 
  in 
  this 
  youngest 
  stage 
  extends 
  backward 
  be- 
  

   yond 
  the 
  yelk-sack 
  for 
  a 
  distance 
  equal 
  to 
  half 
  

   the 
  length 
  of 
  the 
  latter 
  before 
  it 
  reaches 
  the 
  edge 
  

   of 
  the 
  ventral 
  fin-fold 
  to 
  terminate 
  at 
  the 
  anus. 
  

   These 
  differences 
  lead 
  me 
  to 
  think 
  that 
  the 
  larval 
  

   fishes 
  figured 
  by 
  Mr. 
  Agassiz 
  as 
  pertaining 
  to 
  the 
  

   species 
  here 
  under 
  consideration, 
  must 
  belong 
  to 
  

   another 
  form, 
  as 
  none 
  of 
  his 
  figures 
  can 
  be 
  rec- 
  , 
  

   onciled 
  with 
  those 
  taken 
  from 
  larvae 
  of 
  the 
  striped 
  J 
  

   bass, 
  the 
  parentage 
  of 
  which 
  is 
  undoubted. 
  In 
  

   this 
  opinion 
  I 
  am 
  most 
  conclusively 
  confirmed 
  by 
  

   a 
  drawing 
  which 
  has 
  fallen 
  iuto 
  my 
  hands, 
  by 
  the 
  

   late 
  Prof. 
  Henry 
  J. 
  Rice, 
  the 
  figure 
  in 
  question 
  

   being 
  drawn 
  from 
  a 
  larval 
  bass 
  in 
  May, 
  1879, 
  on 
  

   the 
  sixteenth 
  day 
  after 
  hatching, 
  and 
  which 
  had 
  

   been 
  reared 
  from 
  a 
  lot 
  of 
  eggs 
  which 
  were 
  artifici- 
  

   ally 
  impregnated. 
  This 
  drawing, 
  which 
  is 
  repro- 
  

   duced 
  here, 
  fig. 
  7, 
  was 
  taken 
  from 
  a 
  young 
  fish 
  

   measuring 
  5 
  n,m 
  in 
  length, 
  and 
  disagrees 
  in 
  many 
  

   important 
  respects 
  from 
  a 
  young 
  fish 
  of 
  the 
  same 
  

   length 
  and 
  represented 
  in 
  fig. 
  3, 
  plate 
  i, 
  in 
  the 
  

   paper 
  by 
  Agassiz 
  already 
  cited. 
  The 
  figure 
  by 
  

   Rice 
  shows 
  the 
  tail 
  of 
  the 
  young 
  striped 
  bass 
  to 
  

   be 
  distinctly 
  spatulate 
  and 
  rounded, 
  and 
  not 
  

   tapering 
  and 
  rather 
  acutely 
  rounded, 
  as 
  figured 
  

   by 
  Agassiz. 
  In 
  Rice's 
  figure 
  the 
  anus 
  is 
  situated 
  

   at 
  a 
  poiut 
  very 
  nearly 
  midway 
  between 
  the 
  tip 
  ot 
  

   the 
  snout 
  and 
  the 
  eud 
  of 
  the 
  tail; 
  in 
  the 
  figure 
  

   of 
  the 
  same 
  stage 
  given 
  by 
  Agassiz 
  the 
  vent 
  opens 
  

   at 
  a 
  point 
  on 
  the 
  ventral 
  border 
  far 
  in 
  advance 
  of 
  

   a 
  point 
  situated 
  midway 
  between 
  the 
  end 
  of 
  the 
  snout 
  and 
  that 
  of 
  the 
  

  

  f 
  

  

  -Am 
  

  

  11\ 
  

  

  a 
  

  

  I 
  V\V 
  

  

  3 
  -A. 
  Agassiz. 
  On 
  the 
  young 
  stages 
  of 
  osseous 
  fishes. 
  

   Arts 
  and 
  Sci., 
  xvii, 
  188*2, 
  pp. 
  274-275, 
  pi. 
  i. 
  

  

  Part 
  iii, 
  Proc. 
  Aui. 
  Acad. 
  

  

  