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.
A dip pen (or nib pen) consists of a metal nib with capillary channels, like that of a fountain pen, mounted on a handle or holder, often made of wood. A dip pen usually has no ink reservoir and must be repeatedly recharged with ink while drawing or writing. The dip pen has certain advantages over a fountain pen. It can use waterproof pigmented (particle-and-binder-based) inks, such as so-called India ink, drawing ink, or acrylic inks, which would destroy a fountain pen by clogging, as well as the traditional iron gall ink, which can cause corrosion in a fountain pen.