24 
whether one or more of these megaspore-cells develop '), are 
questions most probably of systematical interest as well, but 
lying beyond the scheme of this study. It is the number of 
megaspores formed, that interests us now, and whether it is 
possible that two or more megaspores enter in embryosac-for- 
mation, thus affecting the number of nuclei in the mature 
sac. When formulating these two points more exactly, it turns 
out that we have got to study the following lines of deviation 
from the normal type: 
1°. The possibilities of a reduction in the number of megaspores. 
It is known and needs no further commentary that the usual 
number of megaspores is four. Normally three of these desin- 
tegrate as soon as embryosac-development begins. Theoretically 
however we might as well expect a partial or total suppression 
of these non-functioning nuclei. The development of a reduc- 
tion in this direction is fully worked out and represented in 
fig. 3. The (normal) “row of four‘ is figured by A. B shows 
the “row of three“, © the “row of two* and in D “the 
embryosac-mothercell itself is seen functioning as an embryosac.‘ 
In agreement with this gradual suppression, respectively three, 
two, one or none megaspores are seen desintegrating. 
It must be emphasized here again that this reduction series 
rejects all presupposed connections between megaspore-forma- 
tion and chromatine-reduction. When there is a row of four 
or a row of three (fig. 3 A,B) chromatine-reduction is finished 
before embryosac development begins and so coincides with 
megaspore-formation. When however there is only a row of 
two (fig. 3C) the second reduction division — and when there 
is no row at all (fig. 3 D) both divisions — are shifted into 
the germinating megaspore. 
We have already moved some arguments in favour of our 
treating these two processns separately (p. 15, 16 and p. 19). 
Moreover the correctness of this conception will be confirmed 
later on, this idea of a reduction series being in full accordance 
with the vacuolation process. 
_ 1) Complete literature by Pau (1915, p. 110—144). 
