136 Gager. — The Development of the Pollinium and 
The First Division of tjie Pollinium-Cell. 
The nucleus of the young pollinium-cell occupies an ap- 
proximately central position in the cell. As the cell increases 
in size the nucleus enlarges considerably, and the nucleolus 
especially becomes relatively very large, and stains strongly 
with the gentian-violet. The chromatin granules are dis- 
tributed evenly and apparently in a single row on the threads 
of the linin reticulum and stain deeply with the gentian. 
As the time for division approaches, the nucleus migrates 
to the cell-wall of the pollinium-cell and becomes closely 
appressed to it, flattening out at the place of contact (Fig. 26). 
The nuclear membrane seems to disappear along this region, 
and the nucleus gives every indication of being firmly fixed 
to the cell-wall. Previous to the formation of the spindle, 
the nucleolus frequently fragments (Fig. 27), as in the case 
of the nucleolus of the mother-cell, but no wart-like bodies 
could be determined, and there was no suggestion as to the 
mode of fragmentation. There was no evidence that the 
nucleolus always fragments previous to this division. 
The karyokinetic spindle is oriented at right angles to 
the cell-wall (Fig. 28), as described by Caldwell (1899) for 
Lemna minor , and Duggar (1900) for Symplocarpus foetidus 
and Peltandra undulata . It is probably of the ‘ multipolar 
< diarch ' type described by Strasburger (1900), though, on 
account of its minute size, this fact could not be determined 
with certainty. The spindle never becomes bipolar at either 
end as Caldwell and Duggar found, but the twelve chromo- 
somes in the late anaphase stage are arranged at the ends of 
the spindle in rows parallel to the cell-plate (Fig. 29). 
The formation of the cell-wall separating the two daughter- 
cells presents a very interesting figure. As the cell-plate 
lengthens, the ends of it bend toward the wall of the 
pollinium-cell in a manner similar to that described by 
Guignard (1882) for Neottia Nidus avis , by Duggar (1900) 
for Symplocarpus , and by Chamberlin (1899) {ox Finns Laricio, 
forming an arc which cuts off a small lenticular cell. As the 
