EFFORT AND ACCOMPLISHMENT 199 



Our first sketch, borrowed 

 from Kerner, shows some of the 

 odd and diverse shapes. The 

 viscin acts as a sort of bird-lime 

 to fasten the pollen on the in- 

 sect; but sometimes it is pulled 

 out in long, slender threads, like 

 spider-webs, to entangle the in- 

 sect in its meshes. This happens 

 in the case of the Rhododendron 

 hirsutum, the evening-primrose, 

 and the fire-weed. Our second 

 sketch shows groups of pollen- 

 grains thus joined by filaments 

 into a tangled net to ensnare the 

 unwary visitor. All pollen- 

 grains are hollow cases contain- 

 ing fluid and living germ-cells. 

 They have a certain independent 

 life of their own, and a power 

 of spontaneous growth, as if 

 they were seeds in their own 

 right. By experiments, the pol- 

 len of some flowers has been 

 found to live three daj^s, that of 

 others seventy-six. Pollen of 

 palms and cycads if kept dry 



POLLEN GRAINS AND 

 FILAMENTS 



