Introduction: This is a personal account of the author's attempts to solve some of the problems associated with the fixation and embedding of difficult biological materials such as plant tissues, almost all insect tissues, and large pieces of tissues including whole organs.

Historically, the search began in the 1950's with the study of the maize root tip using the relatively new technique of electron microscopy. This system of cells, separated by thick and partially impermeable walls, did not respond well to the procedures most suitable for animal tissues. New approaches were needed and, in time, some were found that were at least useful if not ideal. A brief account of several of these is given in the following paragraphs.

Fixation of plant cells: Potassium permanganate was chosen very early in the study primarily because it worked better for plant cells than did any of the fixation procedures currently available.