324 BOTANICAL GAZETTE [OCTOBER 
writers is further evidence that in Spirogyra, as in Allium, we have 
here but a stage preparatory to the organization of chromosomes, 
and all bodies seen in preceding stages are but amorphous precipi- 
tates, their great variation being due to the colloidal nature of the 
chromatic substance. But slight pressure on the cover glass of 
these whole mounts appears to destroy the spireme appearances; 
the material then appears, as in sections, to consist of dark bodies 
and fine granules. These dark bodies sometimes appear as oblong 
granules. Examination of many slides and of some where the 
centrally lying material has been slightly displaced by the knife 
(fig. 17) indicates that the bodies appear oblong only because the 
filaments are seen endwise. There is nothing to indicate a definite 
-number of these darkly stained bodies which appear to be homologous 
with those termed chromosomes by Mitzcewrtcy (12), WISSEL- 
INGH (13), BERGHs (1), and others. Their appearance as lying in 
a spireme in whole mounts and their subsequent behavior in rela- 
tion to the finer granular material show them to be, with the 
other material, but parts of the as yet unorganized chromosomes. 
Returning to the study of the sections, we find a tendency of 
the deeply stained bodies to gather at the equatorial part of the 
cylinder in longitudinal rows (fig. 16). An illustration of this may 
be seen in the first section of a spindle, where both kinds of material 
show this longitudinal arrangement. A second section, cut deeper 
in the same spindle and so taking in less of the chromatic material, 
does not show such a bewildering array of bodies. Here the spireme 
formation can be seen as distinctly as in the case of the whole 
mounts. It is also in this stage that there can be seen a beginning 
of a trend of both kinds of material to the poles. This orientation 
of the chromatic material to the respective poles of the spindle, 
without the intervention of centrospheres, suggests that at this 
period in karyokinesis the chromatin masses may have acquired 
electrical charges, thus bringing about a state of mutual repulsion. 
A sharp split or rift along the equatorial circumference of the spindle 
does not appear, but instead, the interior (figs. 20-22) and then the 
esos! (fig. 23) becomes gradually cleared of material. As this 
clearing proceeds, it is coincident with an amalgamation (figs. 23; 
24) of the two kinds of material. Amalgamation when observed in 
