484 Introduction to the Study of Science 



pletely contain the flower when it is in the bud stage of develop- 

 ment. The sepals thus arranged form the calyx, or cup-like 

 part of the flower. The sepals, or the calyx, and the petals 

 of the corolla are included in what is known as the floral envelope. 



The buds show that this 

 phrase is appropriate. The 

 floral envelope contains and 

 protects the essential or re- 

 productive organs of the flower 

 or blossom. 

 Anther-' ^/ ^ (\ is ^\~~se fla i The essential parts of the 



FIG. 149. - Diagram of a typical flower, blossom Comprise two sets of 



organs. The first to be ob- 

 served are the small, stem-like parts ranged around inside the 

 corolla. These are the stamens. Each stamen has a swollen 

 or knob-like top, called the anther, which in the fully developed 

 blossom is covered with a fine flour or powder. The powdery 

 material, called the pollen, is very easily detached from the 

 anther, as one's nose or finger may show after smelling or exam- 

 ining the blossom. 



Remove carefully one by one the sepals and petals. To 

 what are the stamens attached? Inside the cycle formed by 

 them is a single stem or stalk which like a pestle is slightly 

 enlarged at the top and much more so at the bottom. The 

 whole part or organ is the pistil. The enlarged top is called 

 the stigma, or when divided into two or more parts, each of 

 the parts is called a stigma. 



The swollen part at the bottom of the pistil is the ovary or 

 egg-container. Cut an ovary of a blossom, such as an apple, 

 peach, or plum, into sections and examine with a magnifying 

 glass. The inner structure reveals a number of thin-walled 

 compartments each containing a very minute body called the 

 ovule or egg-cell. The ovules of a well -matured ovary are, 

 if fertilized, immature seeds. 



These two sets of parts, the stamens, with their pollen-covered 



