THE COMMON ARUM 



Now that we have followed the arum through 

 its development to the flowering stage, and have 

 incidentally discovered that it provides a royal 

 feast of nectar, often for several hundreds of 

 midge-flieS; we may go farther and endeavour to 

 find the reason of the arum's generosity in this 

 direction. 



Like other living things, the arum does not 

 work for nothing, nor does it produce nectar for 

 midge -flies out of kindly feeling towards them. 

 We might almost say that the arum's scheme 

 for entrapping these little flies is a most artful 

 one, and more like the ingenious work of a 

 thinking animal than the blind instinct of a 

 mindless plant. 



In the first place, the arum bloom is not a 

 flower, but what the botanist terms an inflor- 

 escence, that is to say, it is a branch of flowers ; 

 just as a shoot of foxgloves is not a flower 

 but an inflorescence, or a branch of flowers. In 

 Fig. 29 (Plate 19) we see one of the blooms cut 

 open, the illustration showing it just before it 

 reaches the stage when the midges visit it. 

 Now, I have pointed out in the first chapter 

 that a perfect or complete flower consists of four 

 whorls, the green sepals, the coloured petals, the 

 stamens which produce the male fertilising pollen, 

 and the central carpels, or unripe fruits, to the 

 surface of which the pollen is conveyed in the 

 process of fertilisation. But a flower need not 

 always possess all these parts ; almost any whorl 

 may be missing. However, the stamens and 



