846 
Fraser and Snell .— The Vegelative 
straight or hooked rods (PI. LXII, Fig. 1). Some of them are sharply 
contracted near the middle, and all of them show a slight irregularity 
of outline. 
As they reach the narrow end of the spindle they shorten and 
thicken (Fig. 2), become more closely massed, and come into contact 
with their neighbours on either side. 
The daughter nuclei thus newly formed become rounder and more 
definite in outline, and a faint differentiation of the cytoplasm suggests 
that the nuclear membrane has been formed. At the same time the 
close aggregation of the chromosomes loosens, but each remains attached 
to its neighbours by threads of stainable material. While this is taking 
place slits are observed here and there in the middle line of each chromo¬ 
some and seem by their position to be due to the pull of the lateral 
attachments (Fig. 3). 
With the increase of the young nuclei in size both the slits and the 
cross attachments become more marked (Figs. 4, 5); after a time the 
nucleus reaches an approximately spherical shape, and the chromosome 
complex is spread over the surface of the sphere just inside the now clearly 
defined nuclear membrane (Fig. 6). Now also the nucleolus becomes 
visible, appearing first as a drop or drops of stainable material (Fig. 7), and 
usually in relation to one or more of the chromosomes. 
The chromosomes themselves become much less regular in outline 
as their stainable substance is aggregated here and there in irregular 
masses, leaving a relatively thin thread between (Figs. 7, 9). 
At this stage the centre of the nucleus in median section appears 
empty—except perhaps for the presence of one or two nucleoli—and 
is surrounded by a ring of chromatin threads. But above or below the 
middle line a network may be focused, and in it the split and laterally 
attached chromosomes are clearly recognized (Fig. 8). Their ends are by 
this time no longer to be found, and have presumably become joined either 
to those of their lateral neighbours or to those meeting them across the 
poles of the nucleus ; and the longitudinal slits have been pulled out 
to form diamond-shaped areas (Fig. 9). As time goes on, the limits of the 
individual chromosome become less obvious, but the extent to which they 
may be recognized depends partly also on the angle from which the nucleus 
is viewed. Thus the so-called resting stage is reached, and the nuclei, 
which may differ one from another considerably in size (cf. Figs. 9, 10), 
either pass into the ‘ permanent state \ or after a varying period once more 
prepare for division. 
The first indication that division is about to begin is found in the 
breaking down of certain threads of the reticulum which, in favourable 
cases, may be recognized as the cross attachments between the chromosomes 
of the preceding telophase. 
