Generations , and General Cytology of the Uredineae . 331 
chromosomes (Fig. 19 a), but they lie so close together that their exact 
number and length are difficult to make out ; there are certainly at least ten. 
At this stage the spindle was first observed as a very short structure with 
well-marked centrosomes at each pole, lying among, but without any 
distinct relation to, the chromosomes (Fig. 19 b). From the fact that the 
centrosome with a mass of kinoplasm was first observed outside the 
nucleus, and from analogy with the second division, there can be no doubt 
that the spindle is formed in the cytoplasm, between two centrosomes 
which arise by division of the one observed earlier, and that it later comes 
into association with the chromosomes. 
The spindle gradually increases in length, and the closely packed, ill- 
defined chromosomes come into close relation with it (Fig. 20). As the 
spindle lengthens the chromosomes become confined to the more central 
part of the spindle (Figs. 21, 22), which, if originally oblique (Fig. 22 ), 
takes up a position parallel to the long axis of the germ-tube. The 
spindle still continues to elongate and the chromosomes to spread out, 
so that when the spindle has attained its full length, they occupy usually 
two-thirds of its length (Figs. 23-5). 
This stage, at which the spindle has reached its full length, seems to 
correspond with the metaphase, being the one most frequently met with ; 
but no distinct equatorial plate is ever formed. At this stage the form of 
the chromosomes is usually almost completely lost, and they appear to 
have partly fused together, a few free ends (Fig. 23) or the presence 
of irregular lumps of chromatin (Figs. 24, 25) alone suggesting their 
existence. 
The chromatin material then begins to move towards the poles, but 
rarely, as in Fig. 26, are two distinct polar groups to be seen. Usually this 
stage cannot be sharply distinguished from the last, and the chromatin 
lumps merely become strung out from pole to pole and often showing 
a tendency to form two elongated masses (Fig. 29). Sometimes two 
irregular twisted threads forming two clumps can be seen moving towards 
each pole (Fig. 28), and occasionally the masses moving towards the poles 
can be seen to have formed two chromatin networks (Fig. 27). After this 
stage, the suggestion of separate chromosomes becomes usually completely 
lost and the chromatin merely stretches out from pole to pole as two 
elongated dumb-bell-shaped masses (Fig. 30). The chromatin then 
collects at the poles, forming there one irregular mass (Fig. 31), or the 
distinction into separate masses may be clearly maintained at each pole 
( Fi g' 33)- 
During these stages the centrosomes show clear but faintly staining 
polar radiations, which are often of very considerable length (Fig. 24), and in 
the case shown in Fig. 31 extended to the free end of the germ-tube. When 
the chromatin has collected at the poles the two (or four) masses move apart 
