Plate IV.
Blattella germanica.
Fig. 109. Similar stage to figs. 107 and 108; chromosomes U-shaped and not longitudinally split; two centrosomes present (c).
110. Longitudinally split chromosomes.
111-113. Various stages in formation of cross-shaped tetrads.
114-117. Bent rods, U-shapes, split rings, pairs of rods, and rod-shaped tetrads (116), which are equivalent to the crosses of figs. 112-113.
118-122. Metaphase of first maturation division, showing the element x in various positions.
123-127. First maturation spindle in metaphase.
128. Same in anaphase.
129-132. Late anaphase, showing element x double in 129, and a lagging tetrad in 130.
133. Telophase, with the element x in one daughter cell.
134-136. Prophase of second maturation mitosis, showing dyads and element x.
