120 
Arlow Burdette Stout 
loosely aggregated and the individuals can often be distinguished. Tliere 
is considerable Variation in the degree of development attained by the 
spindle fibres and polar rays. Figiire 16 shows a well developed figure 
with rather unusually heavy astral rays; figure 17 is a somewhat later 
Stage of a more weakly developed spindle figure. 
The nuclear menibrane now forms about the whole group of daughter 
chromosomes while they are niassed together. The daughter nucleus 
so formed enlarges and the mass loosens up somewhat, the chromosomes 
become separated, and it is seen that they lie against the menibrane 
and are connected in series as shown in figures 18 and 5 a. For a time 
various chromosomes remain massed together as is seen in figure 18. 
One or more nucleoles appear simultaneously with the formation 
of the menibrane. The nucleus continues to increase in size, the chromo- 
sonies become more widely distributed iiiitil the condition of the resting 
nucleus is again reached. MeanwhUe the cell-plate forms from the cen- 
tral spindle fibres after which the fibroiis System disappears and the 
cytoplasni passes into a finely reticidated and vaciiolated condition. 
Folio wing the telophases there seems to be but little growth in the 
volnnie of the indmdual chromosomes. As one observes the resting 
nuclei he is impressed with the apparently sniaU amoiint of chroniatin 
compared with that present in the dmsion stages. This is partly due 
to the scattered position of the chromosomes because of which only a 
part of them appear in a single optical section. They are, however, niuch 
smaller during the resting stages. Their lisible increase in size is a pre- 
paration for division. 
Tlie characteristic featiires of the cell division in the root tips of 
Carex niay be summarized as foUows: 
1. The chromosomes are individuahzed bodies which can be iden- 
tified not only at every stage in the division, but in resting nuclei as well. 
2. They also maintain a serial arrangement which gives them a 
definite position relative to each other. This anangement in a discrete 
spirem is in evidence in resting nuclei, but is niost conspicuoiis in the 
prophases. 
3. The chromosomes also pass into the equatorial plate in the same 
serial order they had in the prophases and this order is probably main- 
tained through the anaphases. 
The nuclei in the cortex and in the central cylinder fiirther back 
in the root where division has ceased also show the chromosomes as de- 
finitely individuahzed bodies. Figure 1 shows this featiire in typical 
nuclei in elongated cells of the central cylinder. 
