49 
(1914). This author describes the micropylar group as quite 
normal, while the primary chalazal nucleus divides only once, 
and sometimes twice, the six- or eight-nucleate sac thus cor- 
responding to A—I—8a (or la). 
Clintonia borealis’ embryosac (Smitu 1911) is of the Ay—I—5 
type. Here too the type is as pronounced as it was in the 
Onagraceae, and the resemblance to the Oenothera-sac Smiru 
did not fail to notice. Perhaps the suppression of the chalazal 
group may have been induced in this case by the peculiar tetra- 
sporical condition. 
Cypripedium (Pace 1907) was one of the very first abnormal 
sacs discovered, and has never been reinvestigated since. Though 
the description is by the hand of an eminent examiner like 
Miss Pace, when studying the figures of her richly illustrated 
article the conclusion forced itself upon us that not only an- 
other more probable interpretation is possible, but also that 
Miss Pacr’s interpretation does not cover all the data furnished 
by her illustrations. The author describes the development as 
follows: The megaspore-mother-cell gives rise to two daughter- 
cells, of which the inner one (exceptionally the outer one) be- 
comes the embryosac. (fig. 3, type C, p. 25). The primary embryosac- 
nucleus divides only twice. The direction of the spindle in the 
first division is |, of the spindles in the second divisin |. In 
the two-nucleate stage a large central vacuole between the 
nuclei is to be seen. Later the four nuclei should arrange 
themselves as an egg-apparatus, consisting of two synergids 
and the egg, and one free nucleus at the bottom or halfway 
the embryosac. At fertilisation triple fusion should occur be- 
tween this free nucleus, one of the synergids and the second 
male nucleus. i 
It is evident that a development like this cannot be explai- 
ued by the thoughts which underlie this study, based as they 
are upon a fargoing specialising of the nuclei. The large central 
vacuole in the two-nucleate stage places the character of these 
nuclei as micropylar and chalazal beyond doubt, and so accor- 
ding to Pace the chalazal group should have provided the egg, 
to say nothing about a synergid acting as upper polar nucleus. 
Ann, Jard. Bot. Buitenz. Vol. XXXII. 4 
