198 OUR INSECT FRIENDS AND FOES 



to stand directly in front of the opening to the 

 honey tube. The result of this change of 

 position of the anther is that any humble-bee, 

 or other insect of about that size, visiting the 

 flower in search of nectar, must inevitably rub 

 some of the pollen off on to its breast. The 

 remaining stamens in turn ripen and assume the 

 same position, within three, to six or seven, days 

 from the first opening of the flower. After the 

 stamens have all come to maturity, the anthers 

 drop off and the filaments turn down out of the 

 way. The pistil, which in the mean time has 

 elongated, now assumes the position which the 

 stamens had previously occupied, with the 

 result that any humble-bee which had previously 

 visited a younger flower and dusted its breast 

 with pollen, will, on thrusting its proboscis 

 forward and pressing inwards to obtain the 

 nectar, deposit some of the pollen it has brought 

 from the younger flower on to the surface of 

 the stigma. 



There are many flowers which open only at 

 eventide, remaining fully expanded throughout 

 the night, and closing with the coming of the 

 dawn. These flowers have generally white, 

 pale pinkish, or bright yellow petals which 

 show out vividly in the dusk, and in addition 

 are frequently very fragrant during the evening 

 and night; the sweet scent being an additional 

 aid to the light-coloured petals in attracting the 

 visits of insects. The Nottingham Catchfly 

 (Silene nutans) is an interesting example, for 

 while with its sweet scent and pure white or 

 pinkish flowers it attracts night-flying moths 



