1913] VYAMANOUCHI—ZANARDINIA 23 
opposite poles (figs. 94-98). The chromosomes at the poles are 
aggregated together and two new daughter nuclei are formed 
(fig. 99). The daughter nuclei increase in size and reach a com- 
pletely resting condition (fig. 100). The second mitosis takes 
place simultaneously or in succession, with the two nuclei lying 
in the common cytoplasm of the mother cell (figs. 101-104), showing 
clearly in the metaphase 22 chromosomes, the reduced number 
(fig. 102). The 4 nuclei never divide any farther and never grow 
larger than the nuclei in the superficial vegetative cells. 






a 6 c 
FIG. 20.—Portions of thallus showing the origin of a zoosporangium: a, b, c, 2, 3, 
and 4 or 5 layers of superficial cells respectively, the outermost of which in each case 
are rows of zoosporangia. 
The relative position of the axes of the two mitoses and the 
longer axis of the mother cell is variable; the axis of the first mitotic 
figure is either in the direction of the axis of the mother cell or 
slightly oblique or at a right angle. In the second division, when 
the two mitotic figures occur at the same time, the relative position 
shows all possible directions of the axes. All of these mother 
cells show no polarity in regard to the axes of the mitotic figures. 
When the zoospore mother cell has reached the 4-nucleate 
stage, cleavage begins at the periphery of the protoplast, proceeds 
toward the inside, and the protoplasm is quickly cut by curved 
furrows, that finally divide it into uninucleate masses which are 
the zoospore primordia (figs. 106-108). The zoospore primordia 
