70 



ETON NATOKE-STUDY 



fossilised until long after the appearance of many orders of flying 

 insects. 



It is best to watch one or two particular insects, such as 

 the honey bee and humble bee, and note what flowers they visit. 



FIGUKE 190. A Humble Bee visiting Snap-dragon. 



There are certain flowers, for instance, the crown-lily, to which the 

 bee does not go, though apparently it is full of nectar. What, then, 

 is the use of this nectar, and what insects does it attract ? 



A catalogue of plants and their insect visitors can be made in 

 which the time of opening and shutting of the corolla and the feeding- 

 time of the insects may be compared together. 



There can be no doubt that the changes of structure of many 

 flowers and insects directly depend on each other. 



