104 BOTANICAL GAZETTE [AUGUST 
and Hteracium, while in Antennaria and Wikstroemia they have 
been omitted entirely. The archesporial cell develops directly 
into an embryo sac in Balanophora elongata and Elastonema acumi- 
natum investigated by TrEvB, and in Balanophora globosa studied 
by Lorsy. The authors claim that the embryo develops apoga- 
mously. 
In Arceuthobium Oxycedri, according to JOHNSON, two small 
cells are cut off from the lower end of the “embryo sac mother cell.” 
Of the three cells thus formed, the uppermost one, that is, the one 
toward the micropyle, becomes the one-celled stage of the embryo 
sac. ‘TREUB has described the same for Loranthus sphaerocar pus. 
He refers to the two lower cells as “anticlines.’”’ These authors 
make no reference to megaspore formation, nor is the place of the 
reduction division known, yet we may assume that the cells just 
mentioned are megaspores. 
The development of the embryo sac 
Two embryo sacs are formed in each ovary, one from each 
chalazal nucleus, resulting from the division of the megaspore 
mother cell. Since the development of the two sacs is practically 
the same, we need follow the history of but one. The cell which 
gives rise to the gametophyte may be said to become the one- 
celled sac, and on dividing the two-nucleate sac is formed (figs. 14, 
17, 26). No traces of cell walls were observed between these two 
nuclei. Their division results in the formation of the four-nucleate 
sac, m which the two nuclei at each pole of the sac are sister nuclei 
(fig. 27). Simultaneously with the formation of the one-nucleate 
sac, starch and other food materials are being laid down within 
its cavity, and by the completion of the four-nucieate stage it is 
often so densely filled with these substances that the nuclei are 
almost completely hidden (fig. 28). This is especially true of the 
Sacs of Dendrophthora gracile. Ovules of this plant were found in 
which the nuclei of the sac were either degenerating or had entirely 
disappeared as a result of the abundant storage of food. In some 
examples one of the nucelli had been replaced by a cavity filled 
with food materials (fig. 29). The starch and other organic sub- 
stances associated with it evidently serve as nourishment for the 
