Pollen and sperm nuclei development in rye

The development of rye ( Secale cereale L. Gramineae ) pollen grains. was followed in the light microscope from the differentiating division in the microspore to pollen shedding. Particular attention was given to the localization of the generative cell before and during mitosis and to the change in the structure of sperm nuclei during pollen grain maturation.