PLATE 5 



EXPLANATION OP FIGURES 



Growth stages. N. insulata 



41 Very young spermatocyte. X 2250. 



42-43 Formation of scattered masses of chromatin; mitochondrial body lies 

 outside nuclear membrane in fig. 43. X 2250. 



44-45 Formation of spireme; mitochondrial jjlate in fig. 45. X 2250. 



46 Oriented spireme. X 2250. 



47 Withdrawal of spireme loops from karyosphere. X 2250. 

 48-50 Disappearance of spireme loops. X 2250. 



51 Same as fig. 41, drawn to scale of figs. 52-53, to show increase in size of 

 nucleus during growth. X 1350. 

 52-56 Structure of karyosphere during late growth period. X 1350. 

 53 B Nuclear plate viewed from above. X 2250. 



56 From living material. X 1350. 



57 Irregular karyosphere before formation of aster; mitochondrial body has 

 disappeared. X 1350. 



58 Karyosphere rounded, after formation of aster. X 1350. 



59 Chromatin leaving plasmasome. X 1350. 



110 



