The focus of this review is on angioperm generative cell and sperm cells, and their interaction with the vegetative cell nucleus to form a functional assemblage termed as the male germ unit. The formulation of the male germ unit is believed to be an essential prerequisite for the successful completion of the unique process of double fertilization. that is,the fusion of one sperm with the egg to form the zygote and the fusion of the other sperm with the central cell to form the precursor of the nutritive endorperm tissue. Here, data from quantitative three-dimensional transmission electron microscopy are emphasized.