45 
leaving one free polar-nucleus in the cavity of the sac. Ulti- 
mately these four polar nuclei fuse, giving rise to the primary 
endosperm nucleus. The whole development thus answers to the 
form. AAAA—I—5, (fig. 10, p. 43) which is in close agreement 
with the condition in other Euphorbiaceae. Drsstatorrs (1911) 
incredible statement about there being a full tetrad and still 
a 16-nucleate sac in Euphorbia virgata could not be confirmed 
by Mopitewsk1 (1911) as we can easely understand now. 
Garcinia Kydia and G. Treubii as, described by Trevs (1911) 
and Moringa oleifera Lam. (Rutcers 1922) show a reduction in 
both groups. At the micropylar end the division, which ought 
to give rise to the upper polar nucleus, does not occur, at the 
other end development is stopped after the first division. These 
two chalazal nuclei fuse and act as embryosac nucleas, the whole 
development thus corresponding to A—-[la—3b. 
The Podostemaceae investigated by Went (1909, 1910, 1912) 
are of a remarkable uniformity as to the development of the 
embryosac. There is no doubt about the existence of a primary 
micropylar and a primary chalazal nucleus in the two-nucleate 
stage. The chalazal nucleus soon desintegrates while the other 
one develops normally. Formula C—I—4. Lawia Zeylanica (Mac- 
nus, 1913) is less reduced. Here the primary chalazal nucleus 
fuses with the upper polar nucleus: C—I—4. Podostemon subu- 
latus, Hydrobium olivaceum and Farmeria Metzgerioides on the 
other hand seem to represent a more reduced condition. The 
full-grown embryosac shows the customary four nuclei, but in 
these cases no desorganising or fusing nuclei are to be seen 
during the development of the sac. It is evident that the cha- 
lazal group is entirely suppressed, for the usual polarity and 
vacuolation at the two-nucleate stage is missing. The difference 
between the two-nucleate stage of e.g. Lawia and that of Po- 
dostemon etc. can be illustrated by a comparision of fig. 9 
(Taf. XI) and fig. 56 (Taf. XIV) of Magnus’ publication. Also 
the direction of the spindles in the next (last) division leaves 
no doubt about the micropylar character of all four nuclei. It 
is true that the four nuclei are not crowded together at the 
top of the sac as may be seen by the Onagraceae, but the 
