68o Campbell. — Studies on the Araceae. 
In the specimen figured in Fig. 37 one of the synergidae 
was conspicuous, while the second one was smaller, with 
a smaller nucleus ; whether this inequality is frequent in 
Spathicarpa was not determined. 
The Endosperm. 
The endosperm-nucleus increases a good deal in size before 
its first division. It lies just above the antipodal cells, and is 
imbedded in a mass of granular cytoplasm, which exhibits 
a more or less reticulate appearance in sections, probably 
indicating a vacuolate structure in the living state. The 
endosperm-nucleus has a conspicuous nucleolus, and is much 
richer in chromatin than the egg-nucleus. The first division 
of the nucleus was not seen, but from the appearance of the 
very young endosperm there is little question that the first 
division results in the cutting off of a basal endosperm-cell 
from the embryo-sac. The youngest stage observed (Fig. 40) 
consisted of three basal endosperm-cells, with exceedingly 
delicate membranes, and a fourth nucleus lying free in the 
base of the undivided portion of the embryo-sac. From 
a study of older stages, it is clear that the development of the 
endosperm proceeds from the base toward the apex of the 
sac, which soon becomes entirely filled with the cellular 
endosperm. The large, thin-walled primary endosperm-cells 
divide further, so that the cells of the endosperm become 
smaller and their membranes thicker. 
The Antipodal Cells. 
The three small antipodal cells present at the time of 
fertilization are stimulated into active growth and show an 
extraordinary development. Not infrequently, in somewhat 
later stages, four or occasionally more antipodal cells are 
present, but it is probable that the increased number is due to 
a division of one or more of the original antipodal cells, 
subsequent to fertilization. The small compressed antipodal 
cells of the embryo-sac at the time of fertilization elongate 
