lent chromosomes are so disposed as to give the familiar "bouquet
stage," with the loops directed away from the centrosome and sphere
(_c_). Figures 12, 13, and 14 show the later development of the same
stage, the chromatin loops becoming thicker by the concentration of the
smaller granules to form the larger ones seen in figure 14. The loops
now straighten out and extend in various directions across the nuclear
space (figs. 15, 16, 17). In fig. 18_a_ a longitudinal split is seen in
several chromosomes. Figures 18_b_, 19, 20, and 21 show various stages
in the contraction of these split bivalent chromosomes to form
diamond-shaped tetrads, each side of which is a univalent daughter
chromosome. The tetrads come into the spindle in this form (figs. 22,
23), and change to the form shown in figure 24 during the metaphase
(figs. 22, 26, 28). Figures 25 and 27 show the 26 bivalent chromosomes,
or tetrads, in early and late metaphase, respectively, and figures 29,
30, and 31 in anaphase. This is certainly a reduction division, for the
tetrads are always somewhat elongated and come into the spindle with
their longer axes parallel with the axis of the spindle. The aberrant
bodies in these figures are probably remains of the nucleoli; they are
found only in iron-haematoxylin preparations. Figures 31 and 32 show
exceptional cases where the cell has divided. Usually the two daughter
nuclei are formed in an undivided cell. The resting-stage between the
two divisions is only partial. The nucleolus appears and divides into
two (figs. 33-36), and the chromosomes change into the dyad form (fig.
36), in which they come into the second maturation spindle (figs. 37,
38). The equatorial plate again shows 26 chromosomes (fig. 39). The
formation of the spermatozoa is peculiar in that the original
spermatocyte cell-body, as a rule, does not divide; but the four nuclei
resulting from the two maturation divisions develop into sperm-heads in
one cell. All have a nucleolus (fig. 41), and in a slightly later stage
(fig. 42) the elongated nuclei have a distinct centrosome and sphere at
the posterior end. Later stages are shown in figures 43, 44, and 45.

The points of greatest interest in the spermatogenesis of _Termopsis
angusticollis_ are, (1) the fact that no accessory chromosome is
present; (2) that the method of tetrad formation and reduction are
clear, despite the fact that the cells and the chromatin elements are
quite small; and (3) the failure