zi2 BOTANICAL GAZETTE 
bata made up of slightly elongated cells five or six rows thick in 
median section. The integument, about five cells thick, has n 7 
grown well beyond the tip of the nucellus, and its lips have beco: 
somewhat appressed to form the long micropyle. The cells in 
innermost layer in the integument show active division in the dir 
tion of the greatest length of the nucellus, and by their dense pm 0 
plasm and large nuclei stand out aceeeiag ae as a definite laye 
which I shall designate as the “columnar tissue.’ 
After the disappearance of the megaspore sister cells the defail 
integument. The chalazal end is pointed, occupies at this time 
median position in the nucellus, and is apparently active in 
degeneration of the nucellar tissue, in accommodation to its 0 
sion. The daughter nuclei take places at opposite ends of the 
embryo sac (fig. 24), and quickly undergo the second (fig. 25) 4 
third divisions in the normal manner. 
The mature embryo sac is typical in every respect. It is elonga 
to four or five times its width, the sides lie next the columnar ti 
and the base continues to be pointed and median. The synergl 
lie side by side and the egg protrudes a little way below them, n 
the center of the sac. The cytoplasm of the synergidae is de 
and stains heavily with the Flemming triple; that of the egg is greath 
vacuolated. The antipodals lie well together in the conical bi 
of the sac (jig. 26). The polar nuclei meet midway between 
ends of the sac, and after their fusion the endosperm nucleus ¢ 
tinues to occupy this position (fig. 26). After the fusion of the po 
the remaining basal portion of the nucellus. In this activit 
antipodals do not take part. The base of the sac remains p 
but from being median now comes to lie against the columnar | 
at one side of the nucellus by means of the absorption of the nut 
tissue which lay between its previous position and the colu 
tissue. The further enlargement of the sac is accompanied 
pushing downward of the base between the nucellus and co! 
