Plate V.

Figs. 137-141. Dyads contracting for second maturation mitosis.

142. Equatorial plate of second maturation spindle, containing 11 chromosomes.

143-144. Same, with 11 chromosomes and the element x.

145-147. Sections of second maturation spindles; element x dividing in 146 and 147.

148. Telophase of second mitosis.

149. Telophase of second mitosis, showing masses of chromatin left behind in cytoplasm.

150. Spermatid with extranuclear chromatin (a).

151. Similar stage; different view of spindle-remains (s) and of chromatin element (x₂).

152-153. Spermatid with divided spindle-substance and the corresponding double-tailed form.

154-155. Stages between 156 and 158.

156-157. Older spermatids than 151, showing spindle-remains (s) and centrosome (c).

158-160. Later stages in development of sperm-head.

161. Ripe spermatozoön.

162-168. Degenerate spermatids and spermatozoa.