﻿546 
  REPORT 
  OF 
  COMMISSIONER 
  OF 
  FISH 
  AND 
  FISHERIES. 
  [58] 
  

  

  EXPLANATION 
  OF 
  PLATE 
  I. 
  

   Gadus 
  morrhua. 
  (The 
  Cod.) 
  

  

  Fig. 
  1. 
  Young 
  cod 
  5 
  mm 
  long 
  showing 
  the 
  large 
  supracephalic 
  integumentary 
  sinus 
  ss 
  

   over 
  the 
  head 
  and 
  body 
  ; 
  i, 
  intestine 
  ; 
  y, 
  yelk. 
  Viewed 
  from 
  the 
  side, 
  x 
  32. 
  

  

  Fig. 
  2. 
  Same, 
  viewed 
  obliquely 
  from 
  in 
  front 
  to 
  show 
  the 
  size 
  of 
  the 
  sinus 
  ss. 
  

  

  Fig. 
  3. 
  Position 
  of 
  cod's 
  egg 
  in 
  the 
  water 
  shortly 
  after 
  impregnation, 
  showing 
  the 
  

   polar 
  cells, 
  germinal 
  plasma, 
  and 
  micropyle 
  at 
  inferior 
  pole. 
  

  

  Fig. 
  4. 
  Illustrating 
  the 
  inferior 
  position 
  of 
  the 
  blastodisk 
  when 
  the 
  egg 
  of 
  the 
  cod 
  is 
  

   at 
  rest 
  at 
  the 
  surface 
  of 
  the 
  water. 
  

  

  Fig. 
  5. 
  Illustrating 
  the 
  slight 
  rotation 
  of 
  the 
  egg 
  as 
  the 
  embryo 
  is 
  gradually 
  length- 
  

   ened. 
  

  

  Fig. 
  6. 
  Illustrating 
  the 
  quarter-rotation 
  of 
  the 
  egg 
  when 
  the 
  blastopore 
  is 
  about 
  to 
  

   close, 
  bringing 
  the 
  embryo 
  into 
  an 
  inferior 
  position. 
  

  

  