PLATE 1 



EXPLANATION OF FIGURES 



I to 10 Spermatogonia! prophases, early and late. Figure 9 shows a possible 

 sex element. 



II to 14 Spermatogonial metaphase. Stage A. Figures 12 and 14 show 

 possible sex elements. 



15 Transitional from Stage A to Stage B. 



16 and 17 Spermatogonial metaphase. Stage B. 



564 



