The, Flower 



145 



are reduced to mere bunches of stamens and pistils 

 dangling, in the shape of long catkins, in the wind. 



Flowers show many different devices, the object of 

 which is to prevent them from self-fertilising them- 

 selves. The simplest and most common one is seen 

 when, as in the wallflower, the pistil stands up above 

 the stamens. It is thus the first thing to touch any bee 

 that visits the flower, and if some pollen is already on 

 the bee this will reach the pistil before its own pollen 

 does. 



Fig. 72. A. Laburnum flower. B. The stamens of a young Laburnum 

 flower before the pistil is ripe. C. The pistil of an older flower 

 with the stamens withered. 



Another arrangement very often found is for the 

 stamens and pistil to ripen at different times, that is to 

 say, when the pollen boxes open and the pollen is ready 

 for scattering, the pistil is still too young to receive it ; 

 later on, when the pistil is full grown, the stamens are 

 all withered, and any pollen to be of use must come 

 from some other flowers in which the stamens are at an 

 earlier stage. You will understand this process better 

 by looking at a laburnum flower (Fig. 72) : a bee alights 



G. 10 



