THE WORK OF FLOWERS 111 



Examine the stigma of the petunia to see if it is sticky. 

 Touch it to your tongue to learn if it is sweet. 



Before a seed will form, a pollen grain must alight on 

 the stigma. This is the first step in seed formation, which 

 we call pollination. 



It is a rule of Nature that the flowers of few plants care 

 to receive their own pollen. There are very few plants 

 but that have adapted themselves so that they receive 

 pollen from other plants of the same kind. The principal 

 agents in carrying pollen from one plant to another are 

 insects and the wind. 



87. The Flowers which depend upon Insects to carry 

 Pollen. - — Plants which depend upon insects to bring 

 them pollen or to transport their own have : 



(1) Bright colored flowers, which attract the bees and 

 other insects. 



(2) A perfume, or fragrance, as in the case of the clover 

 or plum blossom, which invites the insect. 



(3) Glands bearing nectar, which is gathered by insects 

 and made by bees into honey. 



(4) Pollen, which is gathered by insects for food and 

 which is called beebread when found in the cells of the 

 honeycomb. 



(5) The stigmas so placed that they come in contact 

 with the insect's body. 



(6) Pollen, which sticks to the insect's body. 



(7) Stigmas, which are expanded and sticky to receive 

 the pollen which the insect may bring from other plants. 



88. The Flowers which depend upon Wind to carry 

 Pollen. — Plants which send their pollen by the wind 

 or catch that which drifts through the air have : 



(1) Exposed flowers with no sepals or petals to stop 

 the drifting pollen. 



