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Garden Work 
by two large cells — the synergidse — into the interior of 
the embryo sac. During the growth of the pollen tube there 
are three nuclei in it: one large vegetative nucleus, which is 
concerned with the growth of the tube itself, and two smaller 
nuclei, which are the generative nuclei. When the pollen 
tube has made its full 
growth, and reached 
the inside of the em- 
bryo sac, the apex is 
absorbed, the gener- 
ative nuclei, with part 
of the protoplasm of the 
tube, pass out into the 
embryo sac, and one of 
them makes its way 
to the oosphere — a 
large naked cell within 
the embryo sac — and 
unites with its nucleus. 
This is fertilization. 
The oosphere then 
becomes the oospore. 
Section of an Ovule showing entry of the Pollen- n • r j 
tube into the Embryo-sac A Cell Wall IS formed 
round it, and cell 
division goes on rapidly, ultimately forming the embryo, 
or rudimentary plant. 
In dicotyledonous seeds — the bean, &c. — the whole of 
the food material is stored up in the embryo itself — in the 
fleshy seed leaves, or cotyledons. But in the monocoty- 
ledonous seeds — wheat, &c. — the food material— starch, 
&c. — is stored up in the cells outside the embryo. 
