Reproduction 



351 



is the mere dusting of the stigmatic surfaces with pollen. 

 This pollen may be derived from the anthers of the same 

 blossom, from different flowers, individuals, or species. 



FIG. 95. Flowers of date-palm : staminate cluster (A) and blossoms (a) ; 

 pistillate cluster (B) and blossoms (6) . [After Swingle.] 



If such pollen-grains do not germinate, or if no germ-tubes 

 penetrate the stigma, they may awaken no more response 

 than so much dust. If we may acknowledge faith in the 

 current belief regarding pollen as a factor in " hay fever," 



