64 NATURE STUDY AND AGRICULTURE 
In mustard there are six; in peas, ten; in the rose there 
are several times as many. 
The Pistil.— The pistil has three parts, but sometimes 
only two can be easily recognized. Good examples for be- 
ginners to study are the mustard, pea, and bean. The lower 
end of the pistil is somewhat swollen. This is the ovary, 
and within it are the ovules which are to develop into seeds. 
The stem arising from the ovary is the style, and at the end 
is a slight enlargement called the stzgma. It may be recog- 
nized by its roughened and sticky surface to which the pollen 
adheres. In many flowers, as in the cultivated flax, we find 
a pistil with one ovary and several styles ‘and stigmas. 
Other flowers, like the anemone and buttercup, have a large 
number of small pistils in which only the ovary and stigma 
are noticeable, the style being very short. 
All these parts vary in number, shape, and relative size 
in different flowers, and in some flowers one or more of the 
parts may be wanting entirely. 
The Use of the Parts. — Pisiil and Seeds. — If we watch 
flowers until the petals fall off, and for a few weeks after, 
we shall see that the pistil of the pea and bean develops into 
a pod with seeds, and the pistils of all other kinds of flowers 
develop into various kinds of fruits, in each case containing 
one or more seeds. The production of seeds, then, is the 
office of the pistil. 
Use of Pollen.— But the pollen-bearing stamens are 
equally essential to the production of seeds and fruit, for it 
is easily shown that the seeds will not grow in the pistil 
‘unless pollen from the same kind of flower has fallen upon 
the stigma. This is called pollination. Of course, the stigma 
must be at the right age so that it will be sticky enough to 
hold the pollen fast. The grain of pollen will then sprout, and 
