At sexual maturity, the germ cells in human male divide several times by mitosis to produce a large number of sperma logon ia. In growth phase, each spermatogonium actively grows to a larger primary spermatocyte by obtaining a nourishment from the nourishing cells. In maturation phase, each primary spermatocyte undergoes two successive divisions called maturation divisions. The primary spermatocyte undergoes first maturation division (meiotic) to produce two haploid daughter cells called secondary spermatocytes. Both secondary spermatocytes undergo second maturation division to form four haploid spermatids. The transformation of spermatids In to spermatozoa is called spermiogenesis or spermateliosis.