1904] OPPERMAN: LIFE HISTORY OF ASTER 359 
Moreover, the two small nuclei at the micropylar end of the 
embryo sac doubtless represent the synergids, now in a state of 
disintegration. Therefore, it seems to the writer most improbable 
that either egg had its originin asynergid. Iam aware that one 
of the two nuclei just above and at one side of the upper egg 
may represent the tube nucleus, but we have no direct evidence 
that such is the case, and it has not yet been demonstrated that 
the tube nucleus enters the embryo sac in Aster. Judging from 
the structure of the micropylar end of this embryo sac and from 
the position of the unusual nuclei, the most probable, and also the 
most simple interpretation of this phenomenon is that the upper 
egy apparatus was formed in the usual way, and that the lower 
egg and the endosperm nucleus associated with it were derived 
from one of the three original antipodal cells. 
We have here not only the remarkable occurrence of a dis- 
tinctly outlined egg associated with a large definitive nucleus in 
the antipodal region of the embryo sac, but also the interesting 
phenomenon of the fertilization of that egg. Whether a sperm 
nucleus has already fused with the upper egg or with the endo- 
sperm nucleus cannot be ascertained. One of the sperm nuclei, 
however, has passed to the lower part of the embryo sac to fuse 
with the lower oosphere. The sperm is more or less banana- 
shaped and is just pressing itself against the cytoplasm of the © 
egg. It has somewhat the appearance of the sperm nuclei of 
Paris quadrifolia, as described in the recent paper of Ernst 
(1902). 
This discovery of an antipodal functioning as an egg and 
about to be fertilized is a very significant fact, and has an impor- 
tant bearing on the problem of the homologies of the antipodals. 
It has been shown by different investigators that all the nuclei of 
the embryo sac except the antipodals are capable of being fer- 
tilized and may therefore be considered as potential eggs. As 
already stated, Chamberlain (1895) reports the occurrence of a 
Nucleus in the enlarged end cell of the antipodals, which he 
believes to be an oosphere, formed by one of the nuclei of the 
antipodal region surrounding itself with cytoplasm, and he 
Suggests that we need only to observe an actual case of fertiliza- 
