i88 OUR INSECT FRIENDS AND FOES 



answer. A bee visiting a thrum-eyed flower 

 thrusts its long proboscis down the corolla-tube 

 in search of the sip of nectar which it expects to 

 find. In doing this the insect brings the base of 

 its proboscis and the front of its head against the 

 stamens at the top of the tube, and some of the 

 golden pollen dust becomes attached; and so 

 long as it continues to visit the thrum-eyed 

 flowers, it will continue to collect, without 

 getting rid of any of the pollen grains. But 

 when the bee flies away to a pin-eyed Primrose, 

 then the part of its proboscis and head on which 

 the pollen of the thrum-eyed flower has collected, 

 will now come into contact with the long-styled 

 stigma at the top of the corolla-tube, and some 

 of the pollen grains will be rubbed off on to it, 

 and will fertilize it ; while at the same time the 

 insect will be collecting on the hairs of his 

 proboscis, lower down the corolla-tube, pollen 

 from the stamens of the pin-eyed flower, which 

 in turn will be rubbed off on to the sensitive 

 surface of the short-styled stigma of a thrum- 

 eyed flower. Here, then, is a most ingenious 

 arrangement for obtaining the benefit of cross- 

 fertilization through the visits of an insect, by 

 which it is assured that every pin-eyed blossom 

 shall always be fertilized by pollen from a thrum 

 eyed flower, and every thrum-eyed by a pin- 

 eyed one. 



A little later in the spring the beautiful dark 

 green leaves of the Cuckoo-pint, or Lords-and- 

 Ladies (Arum macutatum), attract our attention, 

 and amongst the leaves we see the paler tints 

 of the flower spathes, peeping up like little green 



