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.
The Ball Pen Side. One defining characteristic of a stylus pen is that it does not always have feature a working ink pen. Lots of stylus pens use ballpoint innovation. To make the pen work, ink is loaded into a pressurized tube capped on one end and sealed by a small metal roller ball on the other. The roller ball functions as a cap of its own, plugging off the end of the ink cartridge to keep the ink fresh and kept in the cylinder.