(402 ) 
96. After first iaanes of megaspore-mother-cell. XX 440. 
97. Four megaspores. XX 440. 
98. Mitoses of the pee on sac nuclei preceding eight-cell stage. < 440. 
99-100, Stages approaching definitive embryo-sac. Showing aggregation 
of starch. X 440. 
Ior. Illustrating first division of odspore and young endosperm. X 440. 
1o2. Embryo of five or six cells. oO. 
184. 
. Diagrammatic sketch showing relative proportions of embryo, endo- 
a and nucellus. (e) 
106, Same embryo with upper part of endosperm. X 184. 
to7. Older embryo, X 184. 
Benincasa hispida (PLATE 65). 
108. Apex of very young ovule before formation of archesporium. X 440. 
X 440. 
114. Ditto, slightly later. > 440. 
115. Showing lines of cleavage in embryo. X 440. 
116. Endosperm and disintegrating nucellus. > 440. 
Citrullus Citrullus (PLATES 65 AND 66). 
117. Apex of nucellus; primary sporogenous cell and tapetum. X 312. 
118. Process of formation of megaspores. oO. 
IIg-121. Two, four, and eight-cell stages in embryo-sac formation. X< 
oO. 
J21-122a. Different aspects of the embryo-sac near time of maturity. 
oo omitted from 122a. Oo. 
os Oéspore and growing Bee X 440. 
124. Diagram of embryo, endosperm and nucellus; 1’, representing 
“pocket” of cells around end of haustorium. Oo. 
x 4 
125. Embryo and upper part of endosperm indicated in 124. 440. 
126. Showing terminal portion of haustorium and structure of ‘‘ pocket.” 
312. 
Cucurbita Pepo (PLATES 66 AND 67). 
127. Primary sporogenous cell and tapetum (?). > 440. 
128. Same at later stage (megaspore-mother-cell). > 440. 
129. After first division of megaspore-mother-cell.  44o. 
1z9a. The four nen x 440. 
130. Four-celled embryo-sa X 440. 
131. Embryo-sac of eight ie Early stages in differentiation of parts. 
440, 
432. Definitive embryo-sac containing starch. Antipodals vestigial. 
x 440. 
