THE EFFECT OF TEMPERATURE ON THE RADIAL SYMMETRY OF STAURASTRUM POLYMORPHUM

Abstract
SUMMARY: Staurastrum polymorphum Bréb. is a desmid showing different types of symmetry within a clone. Low temperature favors the formation of the quadriradiate form; high temperature favors the formation of the triradiate form. The change from one form to the other has been observed to occur abruptly in a single division. Possible mechanisms for the effect are discussed. The work is correlated with field observations by a previous writer.