478 ANDREWS: EmMBRYO-SAC OF HYBANTHUS CONCOLOR 
divisions in the tapetal region is not shown. Instances were no- 
ticed where before and also after the formation of the primary 
tapetal cell the mother-cell of the embryo-sac divided longitu- 
dinally. These, however, in every instance divided into cells 
like those usually surrounding the embryo-sac mother-cell but 
were more granular. 
The embryo-sac mother-cell divided first into two and then 
into four cells in the usual way. These divisions were often very 
irregular, as in some cases (FIG. 3) they were nearly vertical, and 
as shown by FIG. 4 were completely vertical after the first division. 
The formation of the embryo-sac by the dissolution of these four 
cells generally begins with the lowest one of the tetrad and proceeds 
apically as regards the ovule through the other three. This is 
not always the case, for some instances were noticed in this same 
plant where the dissolution began with the next to the lowest 
cell of the tetrad as shown in Fic. 7. The embryo-sac, formed by 
the destruction of the tetrad as well as some of the surrounding 
cells, is very large. 
The egg apparatus and antipodal cells in this plant are un- 
usually large, as shown by Fic. 8. They frequently extend nearly 
across the embryo-sac lengthwise. The secondary nucleus was 
usually rather small. 
INDIANA UNIVERSITY, 
BLOOMINGTON, INDIANA. 
