148 77V THE GUIANA FOREST. 



Bees kept up a continual irritation in their search 

 for nectar, and caused the sensitive stigma to 

 recoil as it were and bring its petals closer 

 together. Only the bees with the longest pro- 

 boscis could now reach the reservoir, but there 

 were still enough of these to keep up the irritation. 

 As generation after generation passed, the deepen- 

 ing and elongation still continued, until now we 

 have flowers with tubes six inches or more in 

 depth, and humble bees, the proboscids of which 

 are able to sip nectar from the very deepest, at 

 the same time performing the necessary work of 

 fertilisation. 



A great deal more might be said of flowers, 

 but we are unable to deal with other than a few 

 of their contrivances, and must proceed to the fruit. 

 Here also the interdependence of plants and animals 

 is beautifully exemplified. But, instead of insects, 

 we now have to deal with birds, bats, rodents, 

 monkeys, and even fishes. Most of the fruits of 

 the tropics have succeeded in protecting them- 

 selves against insects, and are consequently never 

 subject to the attacks of wasps like their cousins 

 of more temperate climes. It is true that beetles 

 make sad havoc among them, but otherwise, their 

 thick skins are impenetrable to anything smaller 

 than birds or bats. The orange family seems to 



