Reconquest of the Water 



From the very moment when these tiny infant lobes 

 emerge from the protecting mother-sheath, the gentle 

 pulling and swaying of the current is acting upon them 

 and they yield to it ; indeed, they are always swaying 

 to and fro in the water, and in rivers seem never to 

 rest at all. 



According to one authority, it is sometimes possible 

 to produce the air-type of leaf under water by using 

 certain salts, which probably check the ordinary expan- 

 sion of submerged leaves.^ 



The real difficulty of water plants arises when flowers 

 have to be produced. In almost all cases the flowering 

 branches rise up above the surface, so that the stamens 

 and pistils are exposed to insects or the winds. But 

 the long-stalked water-lilies simply allow their flowers 

 to float upon the surface, where they are abundantly 

 visited by bees and crowds of other insects. The 

 beautiful arrangements of Vallisneria have been so often 

 explained that we prefer to describe the Canadian weed 

 (Elodea), which is not so well known. The female 

 flower has a very long flower-tube (about 4 to 8 inches), 

 which grows rapidly, and finally opens on the surface 

 of the water. It is beautifully buoyed up by three 

 rows of air-spaces, and so shaped that water cannot get 

 into the long funnel-shaped interior. The male flowers 

 break off and float up to the surface, where the stamens 

 open and set free the pollen. 



The little grains of pollen are covered with minute 

 spines. Because of these little projecting teeth, an air 

 film surrounds the pollen grain, so that it floats 

 (although itself heavier than water) and drifts about on 

 the surface. Should they by chance reach a female 

 flower, they are drawn by capillary attraction into its 

 funnel and so touch a stigma and effect fertilisation.* 

 The point of this story lies in the fact that many pollen 



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