Beer . — Shi dies in Spore Development. III. 647 
markedly in appearance from the sharply defined heterotype spindle, with 
its acute polar extremities. 
The daughter chromosomes continue to move apart until they reach 
the ends of the spindle, where they become closely massed and intertangled 
in two groups corresponding to the two daughter nuclei (Fig. 9). After 
a time the tangle of chromosomes begins to open a little in each daughter 
nucleus, and a new nuclear wall is developed. At this stage of the telo- 
phase the chromosomes are still seen to be arranged for the most part with 
their long axes parallel with the longitudinal axis of the spindle. That is 
to say, they still roughly occupy the positions in which they reached the 
spindle extremities at the conclusion of the metaphase. No vacuolation, 
such as occurs in some other plants, is to be seen in the chromosomes of 
Equisetum . Their substance remains adherent at certain spots where they 
had come into contact when closely massed together at the conclusion ot 
the metaphase, and these points of junction become drawn out into con- 
necting threads when the chromosomes again separate from one another 
during the telophase. The chromosome substance becomes distributed 
along these anastomotic junctions and new lines of connexion appear to 
develop between the chromosomes, so that gradually the outlines of the 
chromosomes become obscured and the young nucleus is seen to contain 
a chromatic reticulum (Figs. 10, 11). This condition endures until the 
prophase of the succeeding division, when the anastomoses are again with- 
drawn and the chromosomes once more become recognizable as distinct 
entities, occupying, roughly, the same relative positions which they held at 
the conclusion of the telophase. 
The activities performed by the so-called ‘ resting ’ nucleus can evidently 
be most satisfactorily performed when the chromatic contents are diffused 
more or less evenly through the nuclear cavity, whilst for the mitotic 
division concentration of this material is essential. It appears to be of 
relatively small importance how the diffusion of the chromatin is effected. 
In some cases it is attained chiefly through the vacuolization of the chromo- 
some bodies ; in others the chromosomes break up into shorter lengths and 
eventually into granules, whilst in such cases as Equisetum the development 
of anastomotic connexions between the chromosomes and the distribution 
of their substance along these branches are the most important factors in 
obtaining a diffusion of the chromatin through the nucleus. I11 any case, 
however this diffusion of the chromosome substance is brought about in the 
telophase, the same steps usually appear to be retraced during the prophase 
of the succeeding division. 
In Equisetum , therefore, the telophase finally leads to the development 
of a typical resting reticulum such as the one with which we started this 
apex by the microtome knife, but the occurrence of obtuse ends was so constant and invariable 
a phenomenon in my preparations that I felt obliged to reject this interpretation. 
