DAVIS: SPERMATOGENESIS. 109 
cytes the autosomes become broken down to a greater extent than in the 
Acrididae, and the chromatin is scattered through the nucleus in 
irregular masses (Fig. 193). I have, however, been unable to dis- 
tinguish any nuclear membrane at this stage, although the nucleus is 
well defined. Figure 194 is a prophase of the second maturation 
division, the longitudinal split in the large autosome being clearly 
shown. Figure 195 shows the metaphase, and Figures 196 and 197 
different stages of the anaphase of the second division. In the large 
autosomes this division is plainly longitudinal and equational, since: 
it is, in all probability, along the plane of the longitudinal split. Here, 
again, the plane of division cannot be determined in the remaining” 
autosomes, but is probably longitudinal. In Figures 198 and 199 is. 
shown the beginning of the telophase of the second division. 
Thus, in the case of the large bivalent autosome both divisions are 
longitudinal, although the first is really a reducing division. In the 
other autosomes the first division is probably transverse, the second 
longitudinal. I have been unable to find the slightest evidence that 
both maturation divisions are transverse, as is held by Otte (:06) to 
be the case in Locusta. 
2. Monosome. 
The monosome in Steiroxys, unlike that in most of the Acrididae,. 
can be easily followed throughout both maturation divisions. At the 
beginning of the maturation period the monosome, which in the pre- 
ceding stage formed a flattened vacuolated plate, becomes more 
compact and is soon converted into a U-shaped element (Plate 7, Figs. 
155-158) by the development of a longitudinal split. It is interesting to: 
note that the monosome has at this time practically the same form as 
during the early growth period, except that it is now much shortened 
and thickened. The arms of the U become closely apposed and 
during the metaphase of the first maturation division (Plate 5, Fig. 73) 
the monosome is seen as a longitudinally split rod lying nearer one 
spindle pole than the other. It usually lies in the cytoplasm at a short 
distance from the spindle, but in favorable cases can be plainly seen 
to be connected by mantle fibers with the nearest pole. As in the 
Acrididae, the monosome (Plate 8, Fig. 190) does not divide during 
the first division. In the majority of cases it passes to one pole of the 
spindle with the autosomes, but occasionally it lags behind (Fig. 191). 
In such cases it never enters the nucleus of the secondary spermato- 
cyte, but lies outside in the cytoplasm, where it forms a conspicuous 
U-shaped element. Figure 193 represents two adjoining secondary 
