Flagellar root maps allow speculative comparisons of root patterns and of their ontogeny.

A method of mapping the patterns of origin of flagellar roots around basal bodies in two-dimensional diagrams is suggested, making allowance for the varied orientations of members of a pair or quartet of basal bodies in a cell. The method is used to compare flagellar root patterns in a wide range of protistan groups, and appears to demonstrate similarities in many areas. Comparison of such patterns in three published examples shows that during the ontogeny of a basal body it may display first one root pattern and then another, so that the root array of a given basal body is not fixed but changes with the position and role of that basal body in the cell.