FLOWERS 



301 



Surrounding the pistil may be found a number of rather slender 

 stalks, with knobs, or enlargements, on the ends (see d, Fig. 132). 

 These structures are called stamens, 

 from a word meaning " thready." 



Flowers differ greatly in size and 

 shape, as well as in color and odor. 

 The various parts differ in many 

 ways, but the pistil and stamen are 

 always and everywhere the organs 

 that have directly to do with seed- 

 making ; and their work is essentially 

 the same in all flowers, no matter 

 how varied they may be in form and 

 arrangement. 



353. The ovary. On cutting open 

 the ovary of a flower we find that it 

 is a hollow box, with a number of 

 compartments in some species (see 

 Fig. 133), containing from one to 

 very many tiny rounded bodies that 

 are normally destined to become 

 seeds. These bodies are called ovules. 

 As time goes on, these ovules en- 

 large, and the ovary also becomes 

 larger. When the seeds are ripe, 

 the ovary has become the fruit. But 

 the changing of ovules into seeds is 

 not simply a matter of growth. Every 

 farmer and gardener knows that it is 

 possible to have a good lot of flowers 

 or blossoms with a very poor crop of 

 fruit, although the conditions for the 

 growth of the plants may be of the 

 best, and although there may be no 

 sign that there is anything diseased or out of order with the plants. 



FIG. 132. Structure of a flower 



The outer set of covering leaves, 

 , a, is called the calyx ; the single 

 parts are sepals. The inner layer, 

 b, b, is the corolla its parts are the 

 petals. The central organ is the 

 pistil; the main body of the pistil, 



f, is the ovary and contains one 

 or many little structures (ovules) 

 capable of becoming seeds. The 

 tip, <?, of the pistil is the stigma ; 

 this is connected with the ovary 

 by the style c. Surrounding the 

 pistil are a number of stamens, d, 

 consisting of a stalk, /i, called the 

 filament, and an enlarged capsule, 



g, called the anther. This con- 

 tains a mass of cells which can 

 be thrown out, *'; these loosened 



cells are called pollen 



