TABLE Y. 



Systematic Survey of some of the most important rhythmical variations ifi 



Egg-cleavage.^*^ 



Only the first column (Amphioxus) presents the original, palingenetic 

 cleavage- hythm, in regular geometrical progression. All the other columns 

 show the descended kenogenetic modifications. 



c = parent-cells. s = cleavage-cells. e = exoderm-cells. 



i = entoderm-cells. 



