POLLEN, OR FLOWER-DUST 103 



family called by gardeners Monarda, which possess 

 the characteristic ridges, in this instance six in 

 number. 



The common vegetable-marrow flower of the 

 kitchen garden produces comparatively large 



Fig. 66. Pollen-grains with the surface reticulated in a regular 

 hexagonal manner 



spherical pollen-grains, shown in Fig. 68, with 

 eight to twelve conspicuous pores each closed with 

 a valve. The extine is studded with tiny spines, 

 and when the intine makes its egress in the 

 form of a pollen-tube it pushes through one of 

 the pores, throwing its closing valve to either 

 side, or removing it altogether : and even this 

 valve will often have several spines on its sur- 

 face. 



And here let us not fail to remember that we 



