1904] MERRIMAN: VEGETATIVE CELL DIVISION 183 
taken from a series fixed in picro-sublimate solution. No 
nuclei in the prophase showing hyaline caps at the poles 
were found in this series. In the drawing of the upper part 
of the nucleus the cytoplasmic aggregations may be seen at the 
poles. The nucleus has elongated in the direction of the long 
axis of the cell. Indications are also present of the ingrowing 
cytoplasmic fibrillae which later meet the linin strands that join 
the spireme coils to each other and to the nuclear membrane. 
Fig. 18 from a series fixed by the same method represents a ple- 
rome cell in similar stage where the nuclear membrane has 
pushed out at the poles into the cytoplasmic aggregations. fig. 
28 from the same series may be taken as a later stage, where the 
nuclear reticulum has completely joined with the cytoplasmic 
fibrillations. The stages in material fixed in Flemming presents 
configurations similar to those in the material fixed in picro-sub- 
limate. An early stage from these preparations showing the 
pushing out.of the nuclear membrane at the poles is seen in jig. 
26,; a somewhat later stage in fg. 27, where the cytoplasmic 
fibrillations can scarcely be distinguished from the nuclear reticu- 
lum. In fig. 6, from another series fixed in Flemming’s solution 
in which the chromatin is well preserved, it would seem as 
though a vacuolization had taken place around the nucleus. 
There is no evidence of such vacuolization in figs. 77 and 25, taken 
from another series fixed in Flemming’s solution, both cells being 
in the same section of the root tip. In both these cells the 
nuclear membrane can be clearly traced, marking out the nuclear 
space from the cytoplasm. Fig. 25 is of a stage later than that 
shown in fig. 17. Here there are no signs of hyaline caps, but 
there is unmistakable evidence that the achromatic figure is 
formed by the elongation of the nucleus accompanied by the 
ingrowing of fibrillations from the cytoplasm. Fig. 30, from a 
preparation fixed in chrom-acetic, is a still later stage, where 
there is but the vaguest trace of a nuclear membrane. The achro- 
matic figure is well formed and indistinctly multipolar. The term 
“monaxial multipolar,” as applied by Hof to distinguish this 
form from the type of multipolar spindle found in the dividing 
macrospore, better describes the achromatic figure at this stage. 
