Vol. 6, 1920 
BOTANY: 1. W. BAILEY 
199 
quire whether it ever occurs in other somatic tissues, and what relation 
it bears to those types of cell plate formation which previously have been 
described by Treub/ Strasburger*^ and Schiirhoff."^ The writer has accu- 
mulated considerable evidence which indicates that the phenomenon in 
question is not confined to the cambium, but occurs in other somatic 
tissues, in elongated or much flattened cells whose planes of division have 
Robinia Pseudo-Acacia L. 
E F G H 
K. Central portion of cambial initial, in tangential longitudinal extension, showing dis- 
appearance of two arcs of the kinoplasmic ring. X 900. 
F. Central portion of cambial initial, in tangential longitudinal extension, showing early 
kinoplasmasome stage in the formation of the cell plate. X 900. 
G. Cambial initial, in tangential longitudinal extension, showing later kinoplasmasome 
stage in the formation or the cell plate. X 450. 
H. The same. Radial longitudinal extension. X 450. 
n. Daughter nucleus. 
k. Kinoplasma. 
one long and one short dimension. Furthermore, a comparative study of 
cytokinesis in different somatic tissues and in cells of different shapes and 
sizes suggests that the various types of cell plate formation, described 
by Treub, Strasburger, Schiirhoff and the writer, are but different phases 
or stages of a single general or fundamental type of cytokinesis. The 
particular expressions of the phenomenon which may occur in any given 
