Plate XII.
Doryphora decemlineata (Family Chrysomelidæ).
Figs. 151-152. Equatorial plates of spermatogonia, 36 chromosomes—35 large, 1 small.
153. First spermatocyte, synizesis stage.
154. First spermatocyte, synapsis stage.
155-158. First spermatocyte, spireme stages.
159. First spermatocyte, spireme segmented and split.
160-163. First spermatocyte, prophases.