332 Blackman . — On the Fertilization , Alternation of 
and the spindle becomes stretched out and very narrow ; the centrosomes and 
radiations are however still clearly visible (Fig. 31). The daughter-nuclei 
are then formed ; each is a somewhat pear-shaped body and consists of 
a mass of perfectly homogeneous staining material. At the pointed end 
of each, the centrosome can be clearly observed ; it is not attached directly 
to the nucleus, but is connected with it by means of a small portion of 
kinoplasmic material which seems to correspond with the end of the 
former spindle (Fig. 33). The centrosome shows distinct radiations 
(F>g- 33 )- 
Under the conditions under which the teleutospores were germinated 
the two second divisions follow immediately on the first. The centrosome 
becomes divided into two (Fig. 34), and between them the spindle appears 
(Fig. 34 a ). At the same stage the nucleus becomes larger and irregular 
in shape, and a few granules appear in it ; in Fig. 34 a they are to be seen 
just where the spindle is in contact with the nucleus, over the edge of 
which it lies. The spindle then becomes arranged in the long axis of the 
germ-tube, and shows distinct polar radiations, while the nucleus, which 
has shown no definite wall from its first formation, is seen as a mass 
of chromatin lying in an irregular way over the spindle (Fig. 35). The 
chromatin then becomes more symmetrically arranged round the spindle, 
and is seen to be granular throughout (Figs. 36, 37). The chromatin then 
takes the form of a distinct network , which at first covers only part of the 
spindle (Fig. 38 a) t but soon spreads over the whole of it, leaving only the 
centrosomes visible (Fig. 38 b). The network of chromatin then becomes 
drawn apart as two portions towards the poles (Fig. 39). In a later stage 
the threads which connected the two main masses may remain visible for 
a time at the poles, and resemble chromosomes (Fig. 40). The chromatin 
then collects at each pole usually as a single mass (Fig. 41), but not 
infrequently it forms two distinct masses (Fig. 41 a). The four daughter- 
nuclei when they are first formed show, as in Fig. 42, a somewhat pear- 
shaped mass of lightly staining homogeneous material, which bears at the 
pointed end a mass of kinoplasm and a distinct centrosome, as in the 
corresponding stage of the first division. The promycelium then becomes 
divided into four cells, and the nuclei gradually take on a normal appear- 
ance, a chromatin network becoming visible and the centrosome apparently 
disappearing (Fig. 43). 
It is clear that though the division in the promycelium of Gymno- 
sporangium is much more typical than Sapin-Trouffy supposed, yet there 
is certainly no chromosome-formation in the second division, and in the 
first division, though distinct chromosomes appear to be present, they seem 
soon to lose their individuality, so that of their splitting or regular separation 
there is very considerable doubt. 
The two chromatin-groups, which are often to be observed both in 
