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fs = 
(188 Structural and Physiological Botany. (Oe 
tube, and then develope into the embryo. Besides the em- 
_bryonié@ vesicles, the embryo-sac usually contains one or 
more cells, the function | 
of which is still un- 
known, and which are 
called the antipodal cells 
(Fig. 360), because they 
are usually found at the 
base of the embryo-sac. 
Of the: miumeronus 
pollen-tubes which, as a 
mile reach the ovule, 
one penetrates through 
the micropyle, and 
reaches the embryo-sac 
pither directly or ~ by 
forcing aside the tissue 
Fic. 360 —Upper part of the 
nucleus of the ovule of 
Crocus ; p the embryo-sac 
with its nucleus 2&; & 
the embryonic vesicles ; 
g the antipodal cells. (x 
75:) 
Fic. 361.—The process of fertilisation in Gladiolus segetum : 1. the two embryonic 
vesicles at the apex of the embryo-sac; 2’ +” the filiform apparatus ; y' y" the 
balls of protoplasm ready for fertilisation; se the wall of the embryo-sac ; 
II. a pollen-tube ¢ 4 which has just fertilised the two embryonic vesicles in con- 
tact with it: the cell-walls which surround the balls of protoplasm are still very 
thin: III. a somewhat later stage; the cell-walls are thicker ; the fertilised 
vesicle y/ is beginning to develope and to divide into two. (x 400.) 
