Grex (biology)

A grex is a multicellular aggregate of amoeba of the groups Acrasiomycota or Dictyosteliida that can be formed when the amoeba run out of food. The grex moves as a unit, and the individual organisms form a fruiting body, in which amoeba are differentiated into stalk cells and spore cells. The latter can be transported by wind or water a distance that is relatively great compared with what the organisms can achieve in their typical form; the former desiccate and die.