﻿554 
  REPORT 
  OF 
  COMMISSIONER 
  OF 
  FISH 
  AND 
  FISHERIES. 
  [66] 
  

  

  EXPLANATION 
  OF 
  PLATE 
  V. 
  

  

  Apeltes 
  quadracus. 
  (Four-spined 
  Stickleback.) 
  

  

  Fig. 
  22. 
  Embryo 
  in 
  the 
  egg, 
  showing 
  the 
  asymmetrically 
  disposed 
  vitelline 
  vessels. 
  

   Figs. 
  23 
  and 
  24. 
  Other 
  views 
  of 
  the 
  same 
  stage, 
  showing 
  the 
  lateral 
  position 
  of 
  the 
  

  

  heart. 
  

   Fig. 
  25. 
  Dorsal 
  view 
  of 
  a 
  recently 
  hatched 
  embryo, 
  showing 
  the 
  distribution 
  of 
  the 
  

  

  brown 
  pigment 
  blotches 
  on 
  the 
  median 
  line 
  and 
  the 
  symmetry 
  in 
  the 
  distribution 
  

  

  of 
  the 
  vascular 
  channels 
  on 
  the 
  dorsal 
  side 
  of 
  the 
  yelk. 
  

   Fig. 
  26. 
  Side 
  view 
  of 
  the 
  same 
  stage, 
  showing 
  the 
  pigmentation 
  and 
  vascular 
  loops 
  in 
  

  

  the 
  dorsal 
  fin-fold. 
  

  

  