8 AGRICULTURE 



contains little, immature, seed-like bodies, called ovules. 



Each ovule may become a seed. But before an ovule can 

 change into a seed, it must be fertilized; 

 that is, a grain of pollen must fall upon 

 the stigma and grow down into the ovule, 

 after which the latter becomes a seed. 



In a circle just outside of the pistil are a 

 number of slender stalks (six on the mustard 

 flower) called the stamens (1,4, Fig. 5 ). The 

 most important part of a stamen is the cap 

 at the top. This is the anther, or pollen 

 case. When the anther is mature, it bursts 



and frees a yellow powder, called pollen. 

 FIG. 6. A PISTIL 



Soon after this powder or pollen is shed, 

 the stamen, now useless, dies. The pollen must be carried 

 by insects or wind or otherwise to the sticky or rough 

 surface of the stigma in the same or in a different flower. 

 If pollen is not brought to the stigma, no seeds develop. 



In a layer just outside of the stamens is the bright- 

 colored part of the flower (2, Fig. 5). This is called the 

 corolla. In many plants, as in the mustard, it is divided 

 into a number of distinct pieces, each being really a colored 

 leaf, called a petal. Fig. 4 shows that there are four petals 

 in the mustard flower. In a layer just outside of these 

 are the green parts of the flower, called sepals (3, Fig. 5). 



Let us see whether most flowers have their parts arranged 

 in the same order, the pistil in the center, the stamens around 

 the pistil, the petals next to these, and outside of all, the 

 sepals. 



Peach blossom. The peach blossom has this same 



