Studies in Spermatogenesis - LightNovelsOnl.com
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_Blepharida rhois_ (_Family Chrysomelidae_).
131-132. First spermatocyte, spireme stages, showing the heterochromosome group.
133-135. First spermatocyte, beginning of metakinesis.
136. First spermatocyte, equatorial plate, _x_ the unequal pair.
137. First spermatocyte, late anaphase, showing the heterochromosomes _l_ and _s_.
138. Second spermatocyte, equatorial plates.
139-140. Second spermatocyte, daughter plates of the two cla.s.ses.
_Silpha americana_ (_Family Silphidae_).
141. Equatorial plate of spermatogonium, 40 chromosomes--39 large, 1 small.
142. Resting nucleus of spermatogonium, showing 2 plasmosomes (_p_).
143-144. First spermatocyte, spireme stage.
145. First spermatocyte, prophase.
146-147. First spermatocyte, metaphase.
148. First spermatocyte, equatorial plate.
149. Second spermatocyte, equatorial plates.
150. Second spermatocyte, showing metakinesis of the small chromosome.
[Ill.u.s.tration: STEVENS PLATE XI.
N. M. S. del.
COLEOPTERA]
PLATE XII.
_Doryphora decemlineata_ (_Family Chrysomelidae_).
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, _a_{1}_, archoplasmic material.
180-186. Spermatids in different stages; _a_{1}_, archoplasmic material from first spermatocyte spindle, _a_{2}_ archoplasmic material from second maturation spindle.
_Spruce-borers_ (_Family Buprestidae_).
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.
[Ill.u.s.tration: STEVENS PLATE XII.
N. M. S. del
COLEOPTERA]
PLATE XIII.
_Adalia bipunctata_ (_Family Coccinellidae_).
FIG. 193. Equatorial plate of spermatogonium, 20 chromosomes--19 large, 1 small.
194. First spermatocyte, spireme stage, _x_ the heterochromosome group.
