144 



DISPERSION OF POLLEN BY THE WIND. 



anthers borne by these filaments are broad and for the most part heart-shaped; the 

 two lobes of which each anther is composed only open on the side turned to the sky, 



Fig. 233.— Mountain Pine {Plnus Pumilio). 



1 A sinf'le polliniferous scale (stamen) seen from above. "- Three polliniferous scales, one above the other, seen from the side. 

 The pollen falling from each anther alights on the upper surface of the stamen next below, s Two spilces of polhmferous 

 scales. * Branch with apical group of staminal flowers from which pollen is being discharged, s Female flower, i, 2 x 10; 

 sx8; 5x2; * natural size. 



so that the small gaping slit through which the pollen has to be discharged into the 

 air faces upw^ard. Consistently with this fact we find that in Plantains it takes 

 a couple of days to disperse all the pollen. The same category includes the Ehiis 



