166 BOTANICAL GAZETTE [ SEPTEMBER 
insisted upon by Strasburger in two of his recent papers.® The 
difference between Strasburger’s observations and mine is that 
in the former only a small portion of any one fiber is used in the 
process of cell plate formation, while in the latter the substance 
of the whole fiber becomes transformed into a portion of thecell 
plate, z.¢., in the one case the cell plate is simply a product of 
the activity of the kinoplasmic fibers, the fibers themselves no! 
being used in the process, while in the other case the cell plate 
is a result of a change of form of the substance composing the 
fibers. The identity in character of the substance of the cell 
plate and that of the spindle fibers has an important bearing 02 
the relations of the different methods of cell division occu 
in different groups of plants. The process of free cell formatio’ 
in the embryo of Ephedra, as described by Strasburget, is a 
interesting case of kinoplasmic activity, in which the division takes 
place around a single nucleus instead of between two nuclei 
in regular cell division. The fact that the membranes # 
formed simultaneously would show that this process goes 0 
around all parts of the nucleus alike. It might be contrasted # | 
this respect with the formation of ascospores, as descr ais 
Harper, in which the growth of the membrane isa progressive om 
and the nucleus is consequently modified in form to esr 
necessity of kinoplasmic activity from one point alone. : 
method of division of the egg from the endosperm mother a 
and the synergids, as described by Mottier*, presents a Pr s 
intermediate between the method of free cell formation © 
Ephedra and that of regular cell division. Here, vie : 
are two nuclei lying adjacent to one another, 
formed in connecting spindles between them, 
the case of one synergid in Mottier’s jig. 24% - 
blindly in the cytoplasm, a cell plate is formed 10 such casts 
following the method of Ephedra. In all of the above ™ 
the formation of a membrane from the fibers is an est ee 
“ Ueber Cytoplasmastructur und Zellhiute. 
4*Ueber das Verhalten der Kerne bei der Entwickelung des & 
+ 123. 4 
der Vorginge bei der Befruchtung. Jahrb. f. wissen. Bot. 31° 
