Abstract: | A method is described for the simultaneous mounting and double staining of mature pollen grains. The medium consists of 50 ml. of glycerol jelly to which 2.5 ml. of methyl green and 2 ml. of phloxine, both in 50% alcoholic solutions, have been added. Prior to the application of the jelly-dye mixture, the pollen is washed with 70% ethanol to remove adhering oils and resins. The staining reaction is differential and permits the rapid classification of pollen grains. The “functional” pollen expands and stains with both dyes whereas the aborted grains remain shrunken and take only the methyl green wall stain. The same reaction functions with orchid seed. |