The individuality of the chromosomes and their serial arrangement, etc. 117 
The Somatic Division. 
In entering the prophases, a nucleus enlarges slightly and the chromo- 
somes increase in size. They retain, however, the same shape they had 
in the resting nuclei. While increasing in size they separate somewhat 
froni each other and become quite evenly distributed against the niiclear 
membrane somewhat as the bivalent chromosomes are placed in dia- 
kinesis. They are also somewhat angular or even drawn out at different 
points as if connected witli each other by cross fibres from various direc- 
tions (figs. 5 b and 6). 
The chromosomes are at this stage almost isodiametric and their 
shape does not itself suggest the trend of the series, still in many of the 
nuclei in this stage of division the series can be followed at various places 
for sonie distance. The connecting Strands of linin are thin and are not 
sharply differentiated from the chromatin by the stain. 
Judging from the frequent occurrence of this stage in sections of 
root tips and young anthers, it must persist for sonie time. It may be 
characterized as the growth stage, and in it the chromosomes make 
their greatest visible increase in size. The resting nuclei ränge in diameter 
from 4,5 to 6,75 ,« with the chromosomes about 0,2 or 0,3 j» in diameter. 
In the prophase stage just described the nuclei are from 6,75 to 7,5 in 
diameter and the chromosomes are from 0,3 to 0,4 /t in diameter. Düring 
later stages of the prophases the nuclei enlarge but little. The chromo- 
somes, however, appear to enlarge somewhat. The relative sizes at 
various stages will be seen by comparison of figures 4, bb, 10, and 11. 
In passing from this stage the chromosomes niove in from the peri- 
phery of the nucleus and their apparent arrangement in a single con- 
tinuous spirem becomes more clear. The spireni is variously twisted and 
coiled about in the nuclear cavity. That it shows no breaks at all can 
not, of course, be estabhshed. There may be several rather long and 
more or less independent series. Figures 7a, 10, and 11 show several 
stages in the appearance of the spirem during the early prophases. 
It is, however, clear in these nuclei of Carex that the chromosomes 
in resting stages and very early prophases do not primarily form a reti- 
culum, but are connected in a series corresponding to the arrangement 
in the spirem as seen in the mid-prophase. The question as to the re- 
lation of the chromosomes from the paternal and maternal parents in the 
last previous fertilization is, of course, involved here and will be taken 
up in Connection with studies of the fertilization processes wliich I shall 
report later. 
