56 THE PELAGIC STAGES OF YOUNG FISHES. 



PLATE XIX. 

 Species No. 25. 



Tigs. 1-7- 



Fig. 1. Just after the closing of the blastopore. Two kinds of pigment already richly developed, but wholly 



confined to the embryo. The three globules coalesce iu the course of a few minutes. X 5a. 

 Fig. 2. Eighteen hours later. A concentration of the yellow pigment in certain regions begins to manifest 



itself. The black chromatophores are fewer iu number than iu the preceding stage. X 55. 

 Just before hatching. No trace of pigment ou the yolk. X 55. 

 Just hatched. The dull brownish-yellow pigment in a state of expansion; it is somewhat denser 



in regions more clearly defined iu Fig. 5. 

 Twenty-four hours old. 

 Seventy-two hours old. Yellow pigment much increased on the reduced yolk-sac, as well as ou the 



head ami fore part of body. 

 Four days old. Most of the pigment has disappeared. 



