56 
There should be a normal development of the micropylar group, 
while at the other end a different number of nuclei, varying 
from 2 till 11, should be produced. Gow however has not seen 
all stadia of development. His record of what he has seen is 
very brief and the figures very few in number. Moreover these 
figures are only outlined and of no use for further research. 
Aglaonema simplex and A. modestum (CAMPBELL, 1912) are five- 
nucleate and of the D—IIa—3b type. 
V. CONCLUSIONS REGARDING SYSTEMATICS AND 
PHYLOGENY. 
Our knowledge of the embryosac development of most families 
is yet too scanty to justify any attempt at an exact system of 
the female gametophyte. The survey however still indicates 
certain tendencies in development and it furnishes some unex- 
pected evidences of relationship worth special mention. 
Among Piperaceae Peperomia shows a regular development 
of four megaspores and a regular reduction in the number ot 
nuclei produced by each of these megaspores. Exactly the same 
tendencies are occasionally met with in Piper. It is only by 
analising gametophytes as we did, that this relationship between 
a 16- and 5-nucleate sac came to light. 
Euphorbiaceae may be either 16-, 8-, 7-, 5- or 4-nucleate. Super- 
ficially any connection between hess types seems to be lacking. 
In fact, however, they are as closely related as possible. Ouly 
the chalazal group of nuclei is affected by a process of reduc- 
tion, which can go as far as total suppression. In the 16-nucleate 
sacs this process is combined with the Sieiceiaals of all four 
megaspores. 
In Penaeaceae the same sorbate of total suppression of 
the chalazal group with a tetrasporical condition is to be seen. 
All Onagraceae are like the Penaeaceac, except their developing 
only one of the four megaspores. 
: Monocotyledones show a great variety of types. Ceduetithe 
processes are still going on in every direction. The number of 
_ Megaspores ranges from four to one, and both the micropy lar 
