126 BOTANICAL GAZETTE [AUGUST 
egg becomes broken up into smaller ones as the fusion nucleus 
approaches it, and in some cases almost disappears ; cften, how- 
ever, the distinct starch-containing protoplasmic sheath of the 
fusion nucleus or its daughter nuclei is surrounded on both sides 
by large vacuoles (fig. 777). 
The two daughter nuclei of the first division very soon pre- 
pare for. the second division. /zg. 722 shows such a nucleus in 
an early stage of mitosis. The chromatin is arranged in distinct 
rods, the linin granules have formed the reticulum, and the large 
plastin nucleolus is conspicuous. /%g. 123 represents a late 
anaphase in the spindle of the second division. The number of 
chromosomes is evidently greater than in the division of the cen- 
tral cell. At this time the distinctive protoplasm of the pro- 
embryo has filled the base of the archegonium and is becoming 
more and more distinct from the ordinary egg cytoplasm above 
it. During this division and the one following, the plastin 
nucleolus is frequently left outside of the daughter nuclei, and 
may be broken up into several parts which lie free in the cyto- 
plasm. ig. 72g gives the usual arrangement of the first four 
nuclei of the proembryo. They lie tetrad-fashion in the base of 
the archegonium, and a narrow zone of disorganizing protoplasm 
is beginning to appear above the starch-containing sheath around 
them. The cytoplasm is arranged in radiating lines from the 
nuclei. In fig. 726 the third division has taken place. Several 
plastin nucleoli are present in the cytoplasm. In fig. 125 the 
four nuclei of the second division are arranged in an unusual 
manner. They lie in one plane at the base of the archegonium 
and are bounded above by a large vacuole. 
Spindles of the third division do not have any definite 
arrangement in reference to each other or to the axis of the 
archegonium, but their position seems to depend a good deal 
upon the width of the archegonium. After the formation of the 
daughter nuclei, however, these become arranged as fig. 116. 
Two are situated side by side at the base, and six lie above them 
in one plane. While this is the usual arrangement, it is not 
uncommon to find only one at the base, while the other seven 
are arranged above it. In a few cases there were three below 
