WENRICH: SPERMATOGENESIS OF PHRYNOTETTIX MAGNUS. 63 
chromosomes upon the mitotic spindle of the first spermatocyte divi- 
sion. ‘The number thus appearing on the spindle is twelve (Plate 4, 
fig. 39). One of them is the accessory chromosome, which is a dyad 
and passes to one pole undivided (Plate 4, fig. 41, X). The eleven 
tetrads represent the other twenty-two spermatogonial chromosomes 
arranged in pairs. One daughter cell of each spermatocyte receives 
eleven dyads and the other receives twelve, the additional one in the 
latter case being the accessory chromosome. 
In the anaphase all the chromosomes appear as V’s, thus showing 
their dyad constitution (fig. 42 and 43). Before this, in the meta- 
phase, the separate chromatids are not discernible, but early in the 
anaphase they separate from each other at the end opposite that 
which is attached to the spindle-fiber, in this way giving rise to the 
V-shaped figures. The V-shaped arrangement persists until the 
metaphase of the succeeding division is reached. 
3. Secondary spermatocytes 'The secondary spermatocytes pre- 
sent only a short restingstage. For this stage, between the formation 
of the secondary spermatocytes and their division, we may employ 
the term interkinesis (intercinése) proposed by Grégoire (’05). The 
extent of diffusion reached by the dyads in interkinesis is much greater 
than that usually described for this stage, as will be seen from figures 
46 and 47 (Plate 4). The dyads reappear however, in the same 
orientation and relative positions that they had before diffusion. 
In the metaphase the dyads show the same double structure that 
they did in the anaphase of the immediately preceding division (Plate 
5, fig. 50-52). The two monads composing each dyad are separated 
from each other in the metaphase, and in the anaphase are carried to 
the poles of the spindle (fig. 54). Half of the secondary spermato- 
cytes show in the plates of the metaphase eleven chromosomes and 
the other half twelve chromosomes, as was to have been expected 
owing to the non-division of the monosome in the division of the 
primary spermatocytes. Figure 50 (Plate 5) shows eleven and 
figure 51 shows twelve chromosomes. 
The term reductional will be used to designate that one of the two 
maturation divisions which results in the separation of the chromo- 
somes that conjugated in synapsis. Correspondingly the term equa- 
tional will be applied to the division in which the halves of whole 
chromosomes are separated. Employing the terminology of Korschelt 
und Heider (’03), we may use the terms prereduction when the first 
maturation division is reductional, and postreduction when the second 
division is reductional. 
