PLATE 5 



EXPLANATION OF FIGURES 



N. shooterii, second division. X 2000 



62 A, B, C Serial sections of entire spindle in side view, showing all 13 chro- 

 mosomes. 



63 and 64 Polar view of metaphase, showing 13 chromosomes. 



65 A, B Serial sections of entire spindle, XY lying side by side. 



66 Side view of anaphase. 



67 A, B Sister groups of early anaphase. 



68 The XY pairs from one individual, showing marked inequality. 



69 and 70 The XY pairs from two other individuals, showing less inequality. 

 71 to 74 The XY pairs from four other individuals, showing still less inequality 



and in some cases an apparent equality. 



75 A, B Sister anaphase groups from the same spindle, X and Y markedly 

 unequal. 



76 A, B Same, X and Y more nearly equal. (A small chromosome is missing 

 in A at the upper left hand corresponding with the one in B.) 



77 A, B Same, X and Y practically equal, making the two groups almost 

 identical. 



78 and 79 Spermatogonial groups, showing 26 chromosomes including five 

 large ones. 



80 Oogonial group, showing 26 chromosomes including six large ones. 



156 



