spermiogenesis

right|thumb|200px|The process of spermatogenesis. 1. Primary spermatocyte 2. Secondary spermatocytes 3. Spermatids 4. Sperm

Spermiogenesis is the final stage of spermatogenesis, during which the spermatids develop into mature spermatozoa. At the beginning of the stage, the spermatid is a more or less circular cell containing a nucleus, Golgi apparatus, centriole and mitochondria; by the end of the process, it has radically transformed into an elongated spermatozoon, complete with a head, midpiece, and tail.