CHAPTER VIII. 
ESSENTIAL FLORAL LEAVES. 
THE andrecium and gynecium may collectively be called the 
essential organs, since they have to do with the formation of 
seed. 
It is a familiar fact that, at certain times of the year, brown 
patches appear on the backs of fern leaves. These are made up 
of minute cases filled with excessively small brown grains. The 
cases are termed sporangia, and the contained grains spores. 
Club-mosses, common in mountainous districts, also produce 
spores, and the yellow powder sold by chemists under the name 
of lycopodium consists entirely of these. ‘The bodies in question 
can give rise to new plants under favourable conditions. 
Flowering plants also produce spores. Pollen is made up of 
innumerable small grains which are of this nature, and every 
ovule, as we shall see further on, contains a cell, the embryo sac, 
which is also a spore. Since stamens and carpels produce these 
bodies, they may be termed spore-leaves or sporophylls, and 
from this point of view the flower may be defined as “a shoot 
modified for spore-bearing.”’ 
‘The stamens are termed male spore-leaves and the carpels 
female spore-leaves. 
The STaAMENS, as we have seen in the buttercup, differ very 
much from the typical leaf form. In the white waterlily, how- 
ever, there are all possible stages between them and petals (fig. 
39). On the other hand, no links connecting stamens and carpels 
are found in normal flowers. 
Number and Arrangement.—In acyclic and hemicyclic flowers 
a large number of spirally arranged stamens are found. An 
instructive example of the former kind is seen in the Scotch fir. 
The flowers of this plant (fig. 45) possess no perianth, and are 
of two kinds—male, with stameus only, and female, with carpels 
only. The ordinary ‘“‘ cones” are the latter, while the former are 
inuch smaller, and crowded together into clusters. They are best 
examined in June, when the pollen is ripe. Hach one consists of 
