INTRODUCTION 23 
style to the ovary, where the ovule is situated, and 
the ovum thus becomes fertilised. The seed thus 
elaborated undergoes with the enclosed embryo a 
resting period and later germinates. 
But before this happens the flower must release 
the seed from its attachment to the parent plant, for 
some fall close to the latter and some are dispersed 
toa distance. It is obviously of advantage, owing to 
the intense struggle for existence, that the latter 
should happen. And as the means of dispersal of 
seeds are of exceeding interest, and a vital part of. 
the life functions of plants, they are described briefly 
hereafter. 
There are, of course, primarily large seeds and 
small seeds. The former are less likely to be dis- 
tributed far except by outside agency, such as 
animals. Small-seeded plants, of which the bulk of 
the British plant types are composed, have their 
seeds blown to a distance by the wind, of course, and 
there are other methods of dispersal of these plants. 
The ovule being enclosed in an ovary, after fertilisa- 
tion a covering or protection for the seed, called the 
fruit, is formed. 
The fruits are commonly termed seeds when the 
covering is meant, not the enclosed seed. The 
envelope which encloses the seed is called the peri- 
carp. But the word fruit really includes covering 
and enclosed seed. 
In order to understand the modes of dispersal some 
description of the types of fruits is necessary. 
