118 BOTANICAL GAZETTE [FEBRUARY 
(fig. 7), but later a large vacuole appears below and sometimes a 
smaller one above the nucleus, the latter consequently taking a position 
nearer the top of the cell (jig. 8). The mature mother cell shows, in 
the cytoplasm below the vacuole, a peculiar kinoplasmic mass (jig. 8) 
similar to those already reported in the mother cells of Thuja (7), 
Taxodium (1), Larix (6), and Taxus (2), and in the eggs of Thuja 
and Taxodium. The significance of this mass has not been deter- 
mined. 
The nucleus soon goes into synapsis (fig. 9), the kinoplasmic 
mass disappearing about the same time. In the single preparation 
showing the next stage, the eight chromosomes, which result from 
synapsis, divide even before the disappearance of the nuclear mem- 
brane and entrance of the spindle fibers, although the latter are visible 
in the surrounding cytoplasm (jig. 10). The chromosomes give no 
indication of their second division, although in some forms such indica- 
tions are usual. Repeated counting of chromosomes on spindles in 
various stages through the prothallium gave the constant number eight. 
Terrap.—The spindle of the first division is peculiar in being 
obliquely placed (figs. rr, 12), possibly as a result of the vacuole in the 
lower part of the cell, the kinoplasmic fibers extending only in the 
cytoplasm next the wall. The lower of the two cells resulting from 
this division is slightly larger (fig. 6) than its sister. It soon mark- 
edly exceeds the other cell, however, the dividing wall arching up 
into the latter (fig. 13). The division of the lower cell (figs. 14, 15) 
precedes that of the upper, which in some cases does not divide at 
all (fig. 14). Usually, however, a linear tetrad is formed (jig. 16), 
the lowest spore of which enlarges rapidly, absorbing the contents of 
the other three. Although the linear arrangement of the four spores 
is most common, other forms of tetrads were observed. One case of 
a bilateral tetrad (fig. 18), and two instances of the transverse division 
of the lower cell followed by the vertical division of the upper cell were 
found. In one of the latter the nucleus of the upper cell has divided, but 
the separating wall has failed to appear (fig. 9). In all cases the lowest 
spore, the one nearest the chalaza, enlarges before the upper ones do, 
and by absorbing material from them and monopolizing most of the 
material coming into the ovule prevents their further development. 
Similar to this earlier development of the lowest spore of the tetrad is 
