Descriptive and quantitative observations of the plasmalemma and nuclear envelope of freeze-fractured root cells are reported for quiescent and early germinating maize embryos. The numerical density of particles exposed on the extracellular fracture faces of the plasmalemma increases significantly between 12 and 24 hr of germination while it remains unchanged on the protoplasmic fracture faces. The plasmalemma is significantly thicker after 24 hr of germination probably due partially to its enrichment in particles. Between 24 and 72 hr of germination there is a significant increase in the density of nucleopores. The fine structure of the nucleopores changes between 4 and 24 hr of germination. The first 24 hr of germination are also characterized by a spectacular rise in the density of particles of the two nuclear membranes. The results are discussed with respect to germination, particularly that of the maize embryo in which several cellular and molecular aspects have already been studied.