12 PAULINE H. DEDERER 
ends of the branches. The largest number of branches observed 
was 6 and this is probably the correct number as sections of later 
ovaries show that each egg cell is connected with five nurse cells. 
Stage c (figs. 38 and 39). The chromosomes are transformed 
into smaller irregular fragments which later assume the form 
of pale delicate threads. There is no trace of the uncoiling, of 
convoluted threads from the chromatin masses to form the 
leptotene stage, as described by Davis (’08) and Wilson CAZ) 
in the spermatogenesis of insects. 
Stage d (fig. 40): The presynaptic leptotene. The threads 
now appear more definite and convoluted. A few irregular clumps 
of chromatin may. be seen, but fewer detached fragments than 
before. Several free ends of the spireme are visible, but it is 
impossible to approximate the number of threads. 
Stage e (figs. 37 b and 43): The synaptic stage or synizesis. 
A study of this period gives most unsatisfactory results. The 
contraction figure seems to follow immediately upon the lep- 
totene stage. The spireme forms a deep-staining mass closely 
and intricately coiled. In some animals the synaptic knot 
shows two kinds of threads, thick and thin, indicating a pos- 
sible parasynapsis. In P. cynthia all parts show the same diam- 
eter throughout. 
Stage f (figs. 37 cand 44): Post-synaptic spireme. ‘The threads 
now begin to spread out through the nuclear cavity. A few free 
ends are visible. In other cases the spireme might be interpreted 
as continuous. It stains deeply as before, and is of the same 
thickness throughout. Several writers have stated that the 
nuclei are not enclosed at this time, the cells forming a syn- 
cytium. In many sections of this material, cell boundaries were 
not to be seen, but in other cases, particularly when Flemming’s 
fluid was used, they could be traced without any difficulty. The 
tubes connecting the cells stain very lightly at this see being 
only occasionally visible. 
From this point on, a gradual differentiation occurs between 
eggs and nurse cells, so that it is convenient to treat the two 
separately. The further nuclear changes in the nurse cells will 
be considered first. 
