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ment between the results of Mr. Sypkexs and the theory of pr Vries 
and Went, which looks upon the vacuoles as hereditary organs of 
the protoplast. If the nucleus were, during division, an isolated whole, 
the question about the origin of the vacuoles, present inside the 
spindle, would perhaps give some difficulty. But we saw, how the 
observations of Mr. SypkmNs prove that we have here ordinary 
vacuoles, already present in the granular protoplasm and which are 
shoved in between the spindle-threads from the outside with the 
protoplasm. 
Yet it will be desirable to give some nearer information about 
this process, since two somewhat divergent cases occur and here 
again a distinction must be made between the nuclear divisions in 
the parietal layer of protoplasm of the embryo-sac and those in the 
first endosperm-layer or in the meristem of the roots of Viera. 
In the latter cases, in which ordinary division of tissue-cells takes 
place, Mr. SypKens observed what follows. In these cells there are 
a number of vacuoles, which are about equivalent and lie round 
the nucleus in the granular protoplasm. After nuclear division this 
protoplasm with its relatively large vacuoles, penetrates into the spindle 
between the connecting-threads, as we saw above. This penetration 
here occurs as well in the equator as more in the neighbourhood of 
the daughter-nuclei. Hence it is the ordinary vacuoles of the mother- 
cell, which shove in between the daughter-nuclei with the protoplasm 
in which they he. Later, when the connecting-threads have been 
dissolved and cell-division takes place, these vacuoles, as well as 
those which did not penetrate into the spindle, are divided equally 
between the two daughter-cells. So the question is here very simple 
and in complete accordance with what vaN WIssELINGH found in 
Spirogyra. Ouly in this latter case the mother-cell has not several 
equivalent vacuoles but a single large one which penetrates laterally 
into the nuclear spindle. 
Somewhat different are the circumstances in the divisions of the 
parietal layer of protoplasm of the embryo-sac. This cell not only 
contains many nuclei but has also a somewhat different structure 
with regard to its vacuoles. If has namely one single large vacuole, 
filling the middle part of the cell, but besides in the parietal layer 
of protoplasm a great number of very small adventitious vacuoles, 
which were very conspicuous in the preparations of Mr. Sypkens, 
stained without washine out of the stain. Now, after nuclear 
division, the granular protoplasm with its many adventitious vacuoles 
penetrates between the daughter-nuelei and the free extremities of 
the connecting threads. From there it penetrates further towards 
