POLLEN-BODIES OF THE ANGIOSPERMS. 
31 
hours, and I very often found tubes which had reached a con- 
siderable length, and appeared otherwise quite normal, to 
have within them the nucleus of the large cell, while the 
vegetative cell, or vegetative cells, remained on the intine 
quite intact (figs. 78, 79). In those cases in which the 
nuclei of the vegetative cells were free they generally, 
though not always, entered the tube, and that later than the 
large nuclei (fig. 77). 
Alisma plantago corresponds wholly with Bromus, except 
that the place where the vegetative cell is formed cannot be 
precisely indicated on the spherical Pollen-body. Attempts 
at cultivation were fruitless. 
In Arum ternatum the vegetative nucleus divides also into 
two. This can easily be seen in Pollen-bodies, which are 
crushed, and then immediately fixed with osmic acid (figs. 
70 — 72). The two small vegetative nuclei are then often still 
surrounded vritli their vegetative protoplasm (fig. 73). The 
nucleus of the large cells appears wrinkled up in the fresh 
Pollen-bodies ; when it is subjected to pressure it assumes 
the most strange forms, which are more or less star-shaped, 
often even the glove-shaped” form of Hartig (fig. 74). 
Cultivation proved barren. 
In the Cyperacece I found the most complicated phenomena 
of development. I specially examined Eleocharis palustris. 
Almost all stages of development can be found in the large 
spikelets. At the time when the lowermost blossoms have 
opened, the Pollen-bodies in the upper ones are still united 
and polygonal ; they have then a large nucleus in which 
one almost always sees several nucleoli (fig. 82). Later 
on the nucleus -divides, and, indeed, it would seem is 
complete usually before the separation of the individual 
Pollen-bodies. As soon, however, as the Pollen-bodies have 
become free and have taken their definite, almost spherical 
shape, a division takes place of that nucleus which lies 
towards the apex of the cell (fig. 84). One of the so 
formed sister-cells divides again, so that we thus have 
four nuclei in the Pollen-body, three small, oval ones 
lying close to one another in the point of the Pollen-body, 
and one large, more central (figs. 85, 86). In most 
nucleoli, often several, are to be seen ; that of the cen- 
tral nucleus surpasses the rest in size. Only exceptionally 
are four nuclei found in the point, giving a total of live. 
The protoplasm, which fills the point and surrounds the 
three little nuclei, often appears brighter than ^hat in the 
other part of the Pollen-body, and occasionally indications 
of plasmatic partition walls can be seen, which mark the 
