74 WONDERS OF PLANT LIFE 



will, both at her entry and exit, be certain to 

 have her body freely powdered with the golden 

 dust. 



In such cases as these we see the relations of 

 the plant and its insect helper at their simplest. 

 Far more elaborate arrangements have been 

 devised to ensure the effective distribution of 

 pollen by insect agency. Many of these are 

 especially remarkable owing to the fact that the 

 flower is designed for the visits of one class of 

 insect, or perhaps for a single species. Thus a 

 number of exotic plants which are introduced 

 into British gardens can never be effectively 

 cross-fertilised, simply because none of our indi- 

 genous insects is fitted for the task. A rather 

 curious case is that of a Brazilian species, Araujia 

 albens, a plant which is of fairly easy culture in 

 the south of England. In its native country the 

 cross-pollination of the Araujia is carried out by 

 large humble-bees, strong enough to force their 

 way in and out of the curious trap-like contrivance 

 which guards the pollen masses. In other places, 

 however, where the plant has been introduced, 

 the flowers are largely visited by moths, which, 

 unaware of the curious device, thrust in their 

 probosces in search of the nectar. Too late the 

 unfortunate insects find that they are caught in 



