PLATE 1 



EXPLANATION OF FIGURES 



1. A hybrid embryo (Fundulus 9 Scomber cf) nearly three weeks old. It is 

 nearly normal in structure and practically pure maternal in the chromatophore 

 complex. Note the total absence of the green chromatophores of the paternal 

 parent species, as contrasted with their presence in figures 2, 3, and 4. The egg 

 is 2.5 mm. in diameter. 



2 A subnormal hybrid embryo (Fundulus9 ScombercT ), showing the anterior 

 end of the body and the rather poorly differentiated eyes. On the large yolk mass 

 note both the square black chromatophores of Fundulus and the branching black 

 chromatophores of Scomber. Note also that the red chromatophores of Fundulus 

 and the green ones of Scomber are about equally numerous. The drawing was 

 made about two weeks after fertilization. 

 (Drawn from life by Kenji Toda.) 



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