Fig. 161. 
Fig. 177. 
Fig. 189. 
WiLcox, — Spermatogenesis. 
Figs. 139-158. 
Figs. 159, 160. 
Figs. 162, 163. 
Figs. 164-171. 
Figs. 172-176. 
Figs. 178-183. 
Figs. 184-188. 
PLATE IV. 
Caloptenus femur-rubrum. 
Spermatid metamorphosis. 
Spermatocytes, first division. 
Spermatocyte, preparatory to first division. 
Spermatocytes with chromatin in dumb-bell stage. 
Spermatogonia. 
Spermatocytes, stages in ring formation. 
Spermatocyte, first division. One centrosome is cut away in 
another section. 
Spermatocytes, ring stages. 
Spermatocytes, spirem stages. 
Spermatogonium, tripolar division. 
