Wilcox. — Spermatogenesis. 



PLATE II. 



Cicada tibicen. 



Figs. 44, 45. Advanced stages in the metamorphosis of spermatids. 



Figs. 46-48. Spermatogonia. 



Figs. 49-61. Spermatocytes, showing different positions of the hody I suppose to 



be the nucleolus. 

 Figs. 62-77. Metamorphosis of spermatids, X 1,400. 

 Figs. 78-103. Metamorphosis of giant spermatids, X 680. 

 Fig. 104. Normal spermatids from same microscopic field as Figures 78, 103, 



X 680. 



