Davis. — Spermatogenesis. 



PLATE 7. 



Figs. 99-111. Successive stages of the monosome in the primary sperma- 

 j>' tocytes of Dissosteira Carolina. 



Figs. 112-114. Monosomes of Arphia tenebrosa during the late growth period. 



Figs. 115-124. Successive stages of the monosome in the primary sperma- 

 tocytes of Melanoplvs femoratus. 



Figs. 125-150. Successive stages of the monosome in the primary sperma- 

 tocytes of Stenohothrus curtipennis. 



Figs. 151-158. Successive stages of the monosome in the primary sperma- 

 tocytes of Steiroxys trilineata. 



Fig. 159. Rod-shaped tetrad of Hippiscus tuberculatus. 



Figs. 160-182 Dissostiera Carolina. 



Figs. 160-164. Successive stages of the rod-shaped type of tetrads. 

 Figs. 165-168. Successive stages of the cross-shaped type of tetrads. 

 Fig. 169. Extreme development of cross-shaped type of tetrad. 

 Figs. 170-174. Successive stages of ring-shaped tetrads. 

 Figs. 175-182. Successive stages of the crossed loops. 

 Figs. 183-188. Large loops of Stenobothrus curtipennis. 



