go BOTANICAL GAZETTE | FEBRUARY 
With the disappearance of the nuclear membrane, there 
is formed a clearly defined multipolar spindle, whose general 
axes from the first are perpendicular to the plane of the first 
division. This readily becomes bipolar in the usual manner. 
The form of the chromosomes as arranged on the nuclear plate 
is more or less quadranglar in front view, and oblong as observed 
from the poles. Viewed axially, there is an evident line of 
splitting, and on fission there result short, rod-shaped, daughter 
segments. The character of this division, of course, depends 
largely upon the character of the first division, and the doubt 
involved in this first division cannot now be cleared up. 
After the formation ’of the four nuclei denoting the future 
microspores, there is a slight reappearance of spindle connections 
between the daughter cells, or, rather, secondary spindles are 
differentiated with very delicate spindle fibers. 
THE MICROSPORE. 
Upon the dissolution of the. mother-cell membrane, the 
tapetal cells become free, and wander in between the maturing 
microspores, Coming in contact with these forming microspores, 
the tapetal cells lose their identity as distinct cells, forming @ 
general protoplasmic stratum, in which the nuclei persist for 
some time. Imbedded in this nourishing layer, the microspores 
rapidly increase in size, at the same time assuming a thicker 
wall. 
When first freed from the mother-cell membrane, the nuclei 
of these microspores do not show a single definite nucleolus. 
Instead, there are usually several irregular masses, which con- 
stitute the chromatin content. With the maturity of the spores, 
a single large nucleolus, more or less spherical in form, is evident, 
although there may be one or more much smaller bodies staining 
similarly. 
DIVISION OF THE MICROSPORE NUCLEUS. 
In neither plant: has the spirem stage of this division been 
Studien thidetat In Symplocarpus the earliest preparations of 
