ILLUSTRATED TERMS. 



15 



The Pistil or Seed-Bearing Organ is divided into three 

 parts : the Ovary, the Style and the Stigma. (Fig. 50.) 



The Ovary is the lower, expanded part of the pistil which 

 contains the ovules, or undeveloped seeds. (Fig. 50.) 



The Style is the slender stalk that usually surmounts the 

 ovary. (Fig. 50.) 



The Stigma is the flat or variously formed body that termi- 

 nates the style. (Fig. 50.) Unlike the other organs of the 

 plant, it is not covered by a thin skin or epidermis. Its surface 

 is, therefore, moist and rough, so that it readily receives and 

 holds the pollen when it is deposited upon its surface. 



t|W St/gma 



Bah*i* 



~.rAT*ir 



Ktn 



Srru 



fumur. 



FIG. 48. 



FIG. 49. 



FIG. 51. FIG. 52. 



Each tiny pollen grain that alights upon the stigma sends 

 out from its under surface a minute tube which pierces down 

 through the style until it reaches an ovule below, which it 

 quickens into life. This is known as the process of Fertiliza- 

 tion. The ovules then develope into Seeds, and the ovary 

 enlarges into the Fruit or Seed Vessel. 



Cross-Fertilization takes place when the pollen of one 

 flower is carried to the stigma of another by some extraneous 

 agency, such as the wind or animal life. 



