178 WILD FLOWER PRESERVATION 



DEVICES FOR PREVENTING THE ENTRANCE OF 

 INSECTS UNABLE TO FERTILIZE THE FLOWER. 



Plants have many devices for preventing 

 the entrance of insects too small or otherwise 

 unable to fertilize their flowers. 



Some insects are too light to shake the pollen 

 out of the anthers, others so smooth that little 

 pollen would attach to their bodies, and some 

 so small that they could crawl into the flowers, 

 rob them of their honey and creep out again 

 without effecting fertilization. 



Hairs at, or in, the throats of flowers prevent 

 the ingress of small insects. (98) 



Hairs and sticky glands on the stems or 

 calyces of plants are also obstacles. When 

 such hairs are magnified they are often seen 

 to be clubbed, branched or hooked. (99, A and 



B) 



Bristly spines or recurved teeth on the bracts 

 protect the florets in some genera of Com- 

 positae. (100, 101) 



