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.
164-171. First spermatocyte, metaphase.
172. First spermatocyte, anaphase.
173-174. First spermatocyte, equatorial plates.
175-176. First spermatocyte, late anaphase.
177. Second spermatocyte, equatorial plates.
178-179. Second spermatocyte, telophase, a1, archoplasmic material.
180-186. Spermatids in different stages; a1, archoplasmic material from first spermatocyte spindle, a2 archoplasmic material from second maturation spindle.
Spruce-borers (Family Buprestidæ).
187. First spermatocyte, metaphase.
188-189. First spermatocyte, equatorial plates of two species, 10 and 11 chromosomes.
190. First spermatocyte, anaphase.
191. Second spermatocyte, equatorial plates containing 9 large chromosomes and 1 small one.
192. Chromosomes from prophase of the first spermatocyte, all from the same cyst.
