Nuclear Division in the Hepatic ae, 483 
to the cell being in a very unstable condition, if I may so 
express it, and if it were not for the extreme regularity with 
which the aggregation phenomenon, above described, appears 
at this stage, I should have regarded it as merely an artificial 
contraction-effect induced by the reagents employed for 
fixing purposes. The close connexion of the linin with the 
nucleolus, and their relative alterations in staining capacity, 
suggests that in these cases the chromatin itself or some 
nearly allied substance may have been stored in the nucleolus 
and is now passing into the linin. At any rate it seems 
difficult to explain the juxtaposition of the two masses apart 
from some such hypothesis, since it does not seem to be 
related to the diffusion of reagents. It may be that it is 
connected with the formation of the spindle, the functional 
relation of the nucleolus to which has recently been suggested 
by Prof. Strasburger 1 . But the fact that the spindle is not 
formed till long after this phase is over, seems to be opposed 
to such a view as applied to this particular case, although 
it by no means follows that the nucleolus may not also be 
connected with the spindle formation in other plants, or 
perhaps in this one too, at a subsequent period. The ‘ aggre- 
gation ’ condition very soon passes over, and the linin filament 
becomes both shorter and thicker. Owing to the small size 
of the object, it is very difficult to be quite certain whether 
a longitudinal splitting of the thread occurs at this period, but 
I think I am justified in stating that it does, but it is of 
a somewhat irregular character and not very well marked. 
At uneven intervals the linin is seen to be very much thinner 
than at other places, and there may nearly always be distin- 
guished two thin filaments lying close together. In Pellia 
it is not nearly so easy to follow out the course of events 
at this stage as in Fossombronia , but what evidence there 
is, all points to the processes in both being in reality quite 
similar ; and this is especially true of the succeeding changes. 
Eventually the chromatin is seen to be almost confined to 
1 Strasburger, Karyokinetische Probleme, Pringsheims Jahrb. f. wiss. Bot., 
Bd. XXVIII. 
