1906] YAMANOUCHI~—POLYSIPHONIA VIOLACEA 447 
the mitotic figures is readily seen by estimating the number of chromosomes 
arranged in the equatorial plate. 
Fic. 128. Sporophytic nucleus in a process from the central cell, from which 
after a mitosis a carpospore will be formed; the nucleus in prophase; 40 chromo- 
somes may be counted. 
Fic. 129. Metaphase of the mitosis which separates the carpospore from the 
Stalk cell. 
Fic. 130. Polar view of the same mitosis cut obliquely, showing 40 chromo- 
somes. 
Fic. 131. Telophase of the same mitosis; the upper nucleus will lie in the 
Carpospore. 
Fic. 132. Section of a cystocarp, showing central cell (cc), stalk cell (sc), 
Catpospore (sp), and paranematal filaments (pf). 
Fic. 133. Stalk cells beginning to fuse together side by side, and their nuclei, 
with other nuclei remaining in the central cell, beginning to disorganize. 
Fie. 134. Disorganizing nuclei in the central cell. 
Fics. 135a-135d. Four sections of a procarp, showing the arrangement of the 
auxiliary cells (compare with diagram 3); the fusion nucleus in the carpogonium 
(carp) shows the mingling of male and female chromosomes. 
PLATE XXVI. 
The tetraspore formation. 
Fic. 136, P Tophase in a cell of the central siphon previous to the formation 
of pericentral cell, showing 4o chromosomes. 
Fic. 137. Metaphase of this mitosis. 
Fic. 138. Anaphase. 
Fic. 139. Polar view of anaphase; 40 chromosomes present. 
Fic. 140. Tip of a filament, showing stages in the formation of the tetraspore 
mother-cell; pc, pericentral cell; sc, stalk cell; tmc, tetraspore mother cell. 
1G. 141. Chromatin network in resting nucleus of pericentral cell. 
IG. 142. Metaphase of the mitosis in the pericentral cell; centrosphere-like 
structures present. 
Fic. 143. Late metaphase of the same. 
Fic. 144. Anaphase. : 
Fic. 145. Telophase; vacuole intruding between the daughter nuclei. 
Fic. 146, Tetraspore mother cell becoming separated from the stalk cell by 
the Cleavage furrow. : es 
1G. 147. Later stage of the above; tetraspore mother cell increased in size; 
the nucleus with delicate linin network. 
1G. 147a. Portion of linin reticulum in jig. 147 under higher i 
Fic. 148. Reticulum becoming transformed into a coarser chromatin network 
with here and there la knots upon the threads. : 
Fic. 148a, Porticas a wtwakboe fig. 148 under higher magnification. 
Fic. 149. Irregular network becoming transformed into more even threads. 
ification. 
