156 HYDROPHILY : ANEMOPHILY [CH. 



transferred from the male flowers to the stigmas of the 

 more or less distant female flowers, several agencies are 

 found effective, viz. wind, water, insects and other animals ; 

 but especially wind and insects. 



Water-pollination (Hydrophily) is rare, but occurs in 

 Vallisneria, and some other Hydrocharideae, where the 

 male flowers are detached and float like boats, and are 

 carried by currents of water, often aided by wind, to the 

 proximity of the female flowers, which project just above 

 the surface of the water and protrude their feathery 

 stigmas so that the pollen-laden anthers of the floating 

 male flowers rub the sticky pollen up against them. 



In Halophila and Zostera the pollen consists of deli- 

 cate long filaments which are carried under the water 

 and catch on to the long slender stigmas. 



Wind-pollination (Anemophily} is very common, as 

 exhibited by most of our native trees, Pines, Oaks, 

 Beeches, Birches, Poplars, and Walnut, by Grasses, Sedges, 

 Reeds, &c., and several marked characteristics are evident 

 in all of these otherwise very different plants. 



In the first place their flowers are small and numerous, 

 inconspicuous, and devoid of striking colours and scents, 

 or of honey. Many of them, especially where the foliage 

 is expansive and would interfere with the dispersal of the 

 pollen by wind, produce their flowers very early in spring 

 and shower the pollen in the high spring winds before the 

 leaf-buds have opened e.g. the Hazel while in others 

 (e.g. the Pines, Firs, &c.) the foliage is so thin that it 

 offers little obstacle to free passage of pollen-laden wind. 



Next we notice that the stigmas are for the most part 

 feathery and offer relatively large catchment-surfaces, as 

 in Grasses, Hazel, Hemp, &c., and the female flowers are 

 commonly grouped into dense inflorescences. 



Then we observe that enormous quantities of pollen 



