1900 | DEVELOPMENT OF THE POLLEN GRAIN 87 
nuclear segment bends upon itself, as in fg. 77, and with further 
growth the normal size is attained. The cytoplasm in Peltandra 
is very loosely netted, and in the vicinity of the nuclear mem- 
brane a marked radial arrangement of kinoplasmic fibers is evi- 
dent during the late stages of chromosome formation, as has been 
abundantly described and figured (figs. 17, 78). 
THE FIRST DIVISION. 
On the disappearance of the nuclear membrane in Symplo- 
carpus the kinoplasmic fibers entering the nuclear hollow are 
quickly oriented as a multipolar spindle with rather indefinite 
apices. The chromosomes are irregularly disposed on these , 
fibers. The next most abundant stage is a multipolar spindle of 
very few poles, as in fig. 6. Finally a bipolar spindle is formed, 
the apices of which do not end ina very definite point (jig. 8). 
When arranged upon the nuclear plate, it is difficult to inter- 
pret the exact form of the chromosomes in Symplocarpus,.as they 
are so short and thick that fission lines and lines of union are 
almost indistinguishable. Looking down upon the chromosomes 
in an axial view, they seem to be somewhat quadrangular. A 
side view of a single segment shows the line along which sepa- 
ration will take place ; anda polar view, fig. 72, seems to indicate 
that the knee representing the original bend must be directed 
toward the center. It would be difficult at this stage to deter- 
mine which plane represents the longitudinal fission and which 
the line of union of the doubled segment. The fission in a 
median plane is more distinct, and the external tips separate 
farther in this plane, as at a, fig. 7. Usually this is so evident, 
even before there is any separation of the daughter segments, as 
to make credible the view that they are so disposed as to sepa- 
rate qualitatively at the first division. 
In Peltandra there is a less definite multipolar spindle than 
m Symplocarpus, although in the former the general form of a 
multipolar spindle is evident (fig. 19). With the completion of 
the bipolar form, the chromosomes ate both centrally and periph- 
erally disposed. The complete spindle is drawn together loosely 
