TI1K STORY-BOOK OF SCIKNC K 



The flower fades, but the ovary begins to ripen its 



seeds. 

 "The vallisneria is a plant that lives under the 



Aval or. It is very common in the Southern Canal. 



Its leaves resemble narrow green ribbons. It is dioe- 



cious, that is to say it has 

 flowers with stamens and 

 those with pistils on differ- 

 ent plants. The pistillate 

 flowers are borne on long, 

 tightly curled stems. The 

 blossoms with stamens 



Dioecious plants (male and fe- have only very short stems. 



male) of Vallisneria Spiralis 



current would carry away the pollen and pre- 

 vent its fastening itself on the stigmas, the quick- 

 ening action of the stamens on the pistil can- 

 not take place. So the vallisneria, fixed by its 

 roots in the mud, is obliged to send its flowers to 

 the surface of the water to let them blossom in the 

 open ai. It is easy for the pistillate flowers. They 

 unwind the curl that supports them, and mount to 

 the surface. But what will the staminate flowers 

 do, fastened as they are to the bottom with their 

 short stems?" 



1 i I cannot undertake to say, ' ' answered Jules. 



"Well, by their own strength, without any exter- 

 nal aid, these flowers pull away from their stems, 

 break their moorings, and mount to the surface to 

 rejoin the pistillate flowers. Then they open their 

 little white corollas and free their pollen to wind and 

 insects, which deposit it on the stigmas. After that 



