(359) 
case of the mother-cell are nuclear structures at all distinct 
(fg. 109). Figures rog, rro and srzz are all drawn to the 
The embryo-sac as the time of fertilization approaches 
assumes a familiar aspect (fig. 172). Some of the more im- 
portant features of the embryo-sac of en¢ncasa are the 
prominence of the egg-apparatus and the antipodals and the 
absence of starch, at least up to the stage of development in- 
dicated by figure 772. The cytoplasm surrounding the polar 
nuclei appears to be rather scant and filled with numerous 
vacuoles. The complete fusion of the polar nuclei was not 
observed. 
The antipodals, though quite prominent, are here also of 
only transient duration. They were not found in any prepara- 
tions of material beyond the fertilization stage, and seem in 
this case to have no special function. As indicated in figure 
112 they seem to be on the eve of disintegration. 
The endosperm is quite similar to some that we have 
already found in previous cases (jig. zz4). In this case also 
it is distributed in a sac-like form, which in the upper portions 
is of the usual thickness (fg. r7¢) but in the lower part is a 
very thin film. Jn this condition, before the first division of 
the fertilized egg, it has made considerable inroads upon the 
tissue of the nucellus. About ten nuclei have been formed 
and these are scattered about irregularly. The division of 
these nuclei, as usual, takes place simultaneously (fig. 773). 
The endosperm of Benzucasa, like that of Lagenaria, soon 
forms a solid mass of cellular tissue (jig. 776). In this case 
also the peripheral portion becomes denser, and in the upper 
portion this takes place earlier than in the lower. The same 
figure shows the appearance of the cells of the nucellus when 
in contact with the endosperm. The first extension of the 
endosperm is toward the chalaza and while the growth is 
rapid in this manner it remains non-cellular. Upon forma- 
tion of cell-walls, growth is retarded. 
The oéspore remains for a short time undivided (fgs. rz}, 
rrg). A globular or pyriform mass of cells is soon formed 
