130 THE OAK 
fertilisation, and the fertilised egg-cell is now termed 
the oospore, and at once begins to grow into the 
embryo. 
It would be very interesting to describe at length 
all the remarkable details of these processes, and their 
morphological meaning in the light of modern biology, but 
the limits and purpose of this little book will not admit 
of that, and I must content myself with this brief résumé. 
During this process of fertilisation the cupule has 
grown up like a scaly wall round the ovary (fig. 34), and 
the tip of the latter is seen peeping out from its orifice. 
We are now in a position to understand generally 
the changes that convert the female flower into the 
_cupped acorn. ‘The fertilised oospore becomes the em- 
bryo (fig. 35, w); it grows at the expense of the contents 
of the embryo-sac, and develops a radicle, a plumule, 
and two relatively large cotyledons, which soon become 
so big that they occupy the whole space in the sac (fig. 
36). Moreover, the embryo-sac increases to make more 
room for this growing embryo. And now comes in a 
curious point. We saw that the ovary consisted of three 
chambers, each containing two ovules; each of these 
six ovules also had its embryo-sac, containing an ege- 
cell, &c., and each of the total of six egg-cells may be 
fertilised by the contents of so many pollen-tubes 
coming from pollen grains on the stigmas. But the 
rule is that five of the ovules with their contents 
perish at an early period, because one strong one takes 
the lead in development, and starves the rest by taking 
