148 THE STORY OP THE PLANTS. 



three. In a very few large grasses, such as the 

 bamboos, the threefold arrangement is much 

 more conspicuous. As a rule the stamens of 

 grasses hang out freely to the wind, and the 

 stigmas are feathery and most graceful in out- 

 line (Fig. 31). The flowers are usually collected 

 in spikes like that of wheat, or in loose clusters 

 like oats; they frequently hang over in pen- 

 dulous bunches. Their success may be gathered 

 from the fact that almost all the great plains in 

 the world, such as the American prairies, the 

 Pampas, and the Steppes, are covered with 

 grasses ; while even in hilly countries the valleys 

 and downs are also largely clad with smaller 

 and more delicate species. No plants assume 

 so great a variety of divergent forms ; the total 

 number of kinds of grasses can hardly be 

 estimated ; in Britain alone we have more than 

 a hundred native species. 



I will give no further examples of wind- 

 fertilised flowers. If you look for yourself you 

 can find dozens on all sides in the fields around 

 you. They may almost always be recognised 

 by these two marked features of the hanging 

 stamens and the feathery stigma. 



Before I pass on to another subject, however, 

 I ought to mention that by no means all flowers 

 are regularly cross-fertilised. There are some 

 degraded types in which self-fertilisation has 

 become habitual. In these plants, which are 

 usually poor and feeble weeds like groundsel 

 and shepherd's purse, the stamens bend round 

 so as to impregnate the pistil in the same 

 blossom. In other less degraded cases the 



