Abstract
Two preparation techniques for light microscopy and 5 for scanning electron microscopy were compared. The most satisfactory method, both from a quantitative point of view, yielding the least variable results, and from a qualitative one, i.e., without causing any distortion of the pollen grains nor of exine structure and sculpture, was critical point drying with dehydration through acetone. The coating and acetolysis of the specimens induced quantitative and qualitative alterations.