448 BOTANICAL GAZETTE [JUNE 
the equatorial plane in such a manner that the end containing 
the two free ends of the original chromatin loop is in contact 
with the spindle fibers. The fibers gradually pull the chromo- 
somes apart in such a manner that the original chromatin loop 
is untwisted and finally cut in two by a transverse division. 
Thus the parts of each chromosome which pass to the daughter 
nuclei represent transverse halves of the original chromatin 
loop, formed from about one twelfth of the double spirem. 
2. The nucleus at first usually has about three nucleoli, each 
with one or more large granular vacuoles. After the longitudi- 
nal splitting of the chromatin band there arise in the nuclei 
numerous small vacuolate bodies. These are successively 
abstricted from the mother nucleolus by a process of budding, 
and give rise to numerous micronucleoli, which all pass out into 
the cytoplasm before the formation of the mother star, and 
later, at about the beginning of the close daughter skeins, these 
micronucleoli all pass back into the daughter nuclei, and by 
aggregation form the new nucleoli of the daughter nuclei. This 
process is repeated for every division of the female gameto- 
phyte. 
3. At about the time of the division of the chromatin 
granules, there appear in the cytoplasm peculiar cytoplasmic 
threads, which pass from one side of the cell to the other, and 
are mostly tangent to the nucleus. Ata later stage, at about 
the beginning of the nucleolar migration, these threads have 
disappeared, and numerous radiating threads pass out at right 
angles from the nuclear surface and extend to the cell walls. 
These radiations seem to hold some relation to the migration of 
the micronucleoli. Similar radiations appear around the daugh- 
ter nuclei, and the micronucleoli, as they are drawn into the 
daughter nuclei, seem to be in contact with these cytoplasmic 
threads. 
oe Ewo centrospheres appear beside the resting nucleus, and 
_ in the mother star stage a single centrosphere appears at each 
pole of the spindle; while a little later, during metakinesis, @ 
aS a _— at each es with a double centrosome. 
