502 
Max Morse 
are still attenuated and delicate. For a time there is no trace of 
tlie longitudinal split (fig. 59) althougli it appears later. There is a 
reduction in the number of threads here, during these stages, as in 
Periplaneta. 
During the synaptic stages, a chromosome-nucleolus is present 
(figs. 57, 58 and 59), which appears decidedly binary during the 
earlicr phases, the moieties becoming nearly fused later (fig. 59). 
Undoubtely this is the same body which we have designated by a 
similar name in the corresponding stages of Periplaneta. 
3. The secondary spermatoeyte. 
In the secondary spermatocytes, some metaphase plates contain 
eleven chromosomes (fig. 60) and others twelve (fig. 61). The material 
for the determination of this point is abundant and since the chromo- 
somes lie well separated from one another (figs. 60 and 61), there is 
no chance for error. The piasmosome or plasmosomes (for unlike 
Periplaneta , there are frequently two or more of these bodies), may 
be readily distinguished in any of the stains used, whether differential 
or otherwise, so that there is no chance of counting them as chro- 
mosomes. 
It is possible to follow the Orientation of the chromosomes of 
the metaphase in this species more clearlv than in Periplaneta. The 
process is represented in figure 62. The attachment of the spindle 
fibres is median in each case, so that the chromosomes are pulled 
out into bend rods or "V’s” (see text-figure III. i). 
We find, therefore, that the behavior of the cells in Leucophcea 
is similar to that shown in Periplaneta. The details of the various 
processes, however, differ more from those of Periplaneta than is the 
case with the other species to be spoken of and these latter are 
more closely related, phylogenetically, to Periplaneta. 
Stylopyga orientalis (L.). 
The principal interest attaclied to the spermatogenesis of this 
species is the relation maintained between the piasmosome and the 
odd chromosome. Even in the spermatogonia, a large plastin body 
occupies a conspicuous position in the metaphase plate, closely 
associated with a chromosome. As to whether the latter is the odd 
chromosome, could not be determined. During the growth period, 
the chromosome-nucleolus is accompanied by a piasmosome which at 
