226 FLASHLIGHTS ON NATURE 



space free from competition, with no other plants 

 to interfere with them, as in the crowded meadows 

 and hedgerows of the land, they spread freely in 

 the sunshine on every side, drinking in from the 

 air the carbonic acid which is the chief food of 

 plants. In short, the round shape is that which 

 foliage naturally assumes when there is no com- 

 petition, no architectural or engineering difficulty, 

 plenty of food and plenty of sunshine. 



The frogbit as a whole, then, is not submerged 

 like the curled pond-weed ; it floats, not rooted, 

 but free. Yet when it comes to flowering, it has 

 to quit the water, just like the great water-beetles, 

 and emerge upon the open air above, so as to 

 expose its flowers to the fertilising insects. These 

 flowers are extremely delicate and beautiful, with 

 three papery white petals, and a yellow centre ; 

 they make the plant a real ornament to all the 

 ponds where it fixes its residence. The males and 

 females grow on separate plants, and aquatic flies 

 act as their ambassadors. Such is the summer life 

 of the frogbit, while fair weather lasts ; but, like 

 all other pond denizens, it has to reckon in the 

 end with the frozen season. 



It does so in a way slightly different from, though 

 analogous to, that of the curled pond-weed. No. 10 

 shows you the frogbit after the flowering season is 

 over, when it begins to anticipate the approach of 

 winter. It then sends out slender runners, like 

 those of the strawberry vine, on the end of each of 

 which is formed a winter bud, which answers to 

 the winter shoots of the curled pond-weed. By- 



