increase in pollen aperture number, suggesting that pollen apertures are under strong selection pressure. This trend can be observed by comparing the aperture patterns in basal angiosperms (including monocots) with those of eudicots. Different developmental strate-gies operate for pollen apertures in basal angiosperms
Reuse your fountain pen by refilling the ink. Use the method that is suitable for your type of pen. 1  Fill ink in a piston converter pen by removing the cap and barrel and then dipping the nib inside the ink bottle. 2  Lower the piston to remove the air inside. 3  When you pull up the piston, the ink will be sucked in.
Battersea Pen Home: Pen sales, repairs, refills, vintage fountain pens. The modern Parker Duofold fountain pen comes in two sizes: the International and the larger Centennial version. The Centennial is about the same size as the original Senior, and the International is similar to the original Special. There is only ONE size of ballpoint and pencil.