804 THE POPULAR SCIENCE MONTHLY. 



We return, after this excursion into the curious world of the 

 AlgcB, to the higher plants, and inquire whether there are not spe- 

 cial adaptations to a life in the water in the conditions of their 

 blossoming. 



The flower of the phanerogam is adapted in general to life in 

 the air and the light. We find, therefore, that the flowers of 

 many water plants with floating leaves aim to reach the surface 

 of the water. They require for the transfer of the pollen to the 

 ovule the aid of the wind or of the insects which hover thickly 

 over the water. Their emergence is effected with the help of 

 floats of various kinds, of which it is sufficient to recall here a 

 much-cited example. In the Vallisneria, the long, grasslike leaves 

 of which form a kind of turf at the bottoms of some of the south 

 European lakes, the inconspicuous male flowers rise in knobby 

 bunches protected by a turgid envelope at the bottom of the 

 water. The female flowers stand singly on very long, threadlike 

 stems which rise to the top of the water. When the pollen has 

 matured, the covering of the male flowers opens and the flowers 

 escape in the form of little balls, which, being very light, rise at 

 once to the surface of the water. Here are unfolded three white 

 leaves, which, to use a figure of Kerner's, float around like pollen- 

 laden canoes, and are so wafted by the wind as to convey their 

 freight to the female flowers. While the fruit is forming, the 

 stems of the female flowers roll up spirally and draw the seeds 

 down into the protecting deeps, to remain there undisturbed till 

 the time of germination. The flowers of many water plants, ex- 

 cept for these processes, remain concealed in the deep through- 

 out their lives. They do not there bring all their functions to 

 fruiting, which can be accomplished only in the air. Without 

 color or fragrance, they are inconspicuous ; their structure is dis- 

 tinguishable only under close examination, and they are proved 

 to be real flowers only by their pollen-shedding and their forma- 

 tion of seeds. Again arise in water plants special tasks. It is in- 

 cumbent upon one to spread itself as widely as possible and estab- 

 lish its posterity in new places, where it may obtain room for free 

 development and will not be dwarfed under the shadow of larger 

 plants. The seeds, therefore, must not stay where they have fallen 

 when ripened. They must be scattered, and by all means carried 

 away from the immediate neighborhood of the mother plant. The 

 fruits or seeds of water plants are therefore largely endowed with 

 aids to swimming, by the help of which they can accomplish long 

 distances. They share this provision with many shore plants, the 

 whole existence of which is connected with the water in more than 

 one respect. Among these is the cocoa palm, the gigantic fruits 

 of which are comparatively very light. Filled within with cocoa- 

 nut milk and cocoa butter, food for the young sprout, they pos- 



