THE MEIOTIC PHENOMENA IN BLAPS 87 
c. Synizesis. So far as the euchromosomes are concerned, 
very little can be added to my former account of this stage (14, 
p. 55). Once formed, these bodies begin to shift their peripheral 
position and become crowded near that pole of the nucleus near- 
est the sphere and centrosome. The degree of contraction is 
slightly variable according to the individual; in some specimens 
a mass of clumped chromosomes is formed, in which it is impos- 
sible to detect individual chromosomes, while in others the 
process does not go so far, although the chromosomes become 
restricted to a half of the nucleus. 
This stage represents the synizesis of other forms, with only 
the difference that, whereas in the latter the contraction usually 
takes place after the leptotene threads have arisen, in Blaps it 
occurs at an earlier stage. Figure 71 shows the beginning of the 
process. In figure 72 two cells in this stage have been repre- 
sented; the nucleus in the cell to the left is seen in optical sec- 
tion. Figure 73 shows the same condition as seen in polar view. 
d., Unraveling stage. This stage is marked, as in other forms, 
by a resolution of all the prochromosomes (with the exception 
of the X-chromosome) into closely convoluted threads which 
then unravel to form the thin threads of the succeeding stage. 
This process is rather difficult to follow in the euchromosomes on 
account of their small size and crowded condition at the pole of the 
nucleus, but in the M-chromosomes it is almost as conspicuous 
as in the best objects that have been studied (fig. 76, a, 6). 
The polar position of the prochromosomes is retained during 
the unraveling stage. Figure 75 shows some phases of this proc- 
ess In a spermatocyte seen in polar view; some threads have al- 
ready appeared, other prochromosomes are unraveling and a few 
are still in the massive condition. 
e. Leptotene stage. ‘The leptotene threads produced by the 
process just described are restricted to the pole of the nucleus in 
contact with the sphere. In polar views it is possible to detect 
the presence of delicate threads, somewhat wavy in appearance, 
the shortest of which are the euchromosomes and small com- 
ponents of the X-complex (fig. 77). Two other threads, much 
longer, conspicuous, and connected with a dense mass, are the 
