518 WARO NAKAHARA 
first spermatocytic division in Forficula, namely, by bending 
of a rod and by opening up of a longitudinally split thread. 
Critical points 
In the entire history of the maturation of the germ cell the 
points where the interpretations diverge are, (1) an early stage 
when the double spireme develops, and (2) a later stage when 
the tetrad becomes formed. ‘These two stages will be designated 
for the sake of convenience as the ‘lepto-zygotene’ and ‘pachy- 
streptotene’ stages, respectively. 
The condition of the chromatin threads at the ‘lepto-zygotene’ 
stage was considered, not only by Meves (’96, 707, ’11), Kings- 
bury (98, 702), Duesburg (08), Fick (07, ’08), and others, but 
also by telosynaptists, as representing a longitudinal splitting 
and as essentially the same as in the corresponding stage of 
prophase in homotypic mitosis. Parasynaptists claim that this 
is the stage when a parallel conjugation, two by two, of simple 
chromatin threads takes place. 
As stated before, there is no evidence of conjugation, nor of 
splitting, in the case of Perla. The condition here might best 
be described as the development of a double spireme out of the 
chromatin reticulum of a resting nucleus, although the duality 
of the spireme may be best interpreted as a precocious splitting. 
In the first place, there are no definitely formed fine undivided 
leptotene threads in the nucleus before the double threads begin 
to appear. It is true that there are many ‘“‘thick and often 
double threads terminating in two undivided diverging thin 
threads like the branches of a Y, which often separate at a wide 
angle and may be traced for a long distance,’ but these are 
hardly adequate to base the conclusion that parasynapsis is 
taking place, because the condition may just as well, or better, 
be attributed to the rearrangement of the reticulum into double 
spiremes. As a matter of fact, the thick threads may be seen 
diverging into more than two thin threads, as observations by 
Fick (07) and also by Janssens and Dumex (’03) have shown. 
It must be concluded that, at least in the case of Perla, there is 
no evidence of synapsis at this stage. Also, since there are no 
clearly differentiated simple threads before the development of 
