PLATE 20 



EXPLANATION OF FIGURES 



82 Total view of a living cardiectomized emliryo of Fundulus. Age nine 

 days. Operation at seventieth hour. Column of erythrocytes can be seen 

 through otocyst. Erythrocytes and endothelium present on anterior yolk but 

 absent on posterior yolk. Eyes very defective. 



83 Transverse section through the otocysts of the embryo represented in 

 figure 82. Erythrocytes indicate precardinal lines. Erth., erythrocytes. 



170 



