84 BOTANICAL GAZETTE [ FEBRUARY 
before and after this condition indicate that in some obscure way 
it must have an effect in the distribution of chromatin to the 
spirem ribbon. The changes evident on the return of the chro- 
matin substance from synapsis are gradual but well marked. All 
phases of the return from this condition and leading to the spi- 
rem stage may be traced in a single anther. 
It has been suggested by some that during the early pro- 
phase of division the cytoplasm is more difficult to fix, and from 
this difficulty may result the contraction termed synapsis. There 
is, however, little evidence for assuming that the cytoplasm 1s 
then so difficult to fix, nor is this condition a constant attendant 
of improper fixing during early prophase stages. The effect of 
diffusion currents, moreover, could not well produce such effects 
as found in Symplocarpus, since diffusion currents sufficiently 
strong to wrap the thread into a chromatic ball would hardly 
leave the nucleolus attached in the characteristic manner mem- 
tioned. 
THE SPIREM STAGE AND SEGMENTATION. 
On freeing itself from the contracted condition by a gradual 
loosening of the coils, the spirem skein in Symplocarpus takes the 
gentian readily, and it is easily traced as one or few coils with 
no anastomoses. The wide looping of the coil is more evident 
at this period than at any other. The thread is then made up 
of numerous adjacent disks of chromatin substance almost homo 
geneous with the linin connections. The chromatin disks become 
more distinct, and the ribbon spaces more noticeable; hence 4 
somewhat nodulate appearance is presented, as in fig. 2. No 
evidence of a longitudinal splitting of the ribbon can be found 
at this time, 
During the initiation of the spirem stage the nucleolus has 4 
distinctly budded form, sometimes consisting of a single largé 
body and of one or two smaller ones closely united, or twe of 
nearly equal size. It is often very clear that the spirem thread 
is connected with these nuclear parts. 
Following that stage in Symplocarpus where the spirem thread 
is uniform, there occurs a more abrupt bending and twisting of 
