Sperm are produced by cells of the testicular tissue, and eggs are formed by the gradual maturation of primordial follicles in the storage ovaries. Spermatozoa are produced from the spermatogenic epithelium, which undergoes several meiotic divisions to form primary spermatocytes, which undergo meiosis to form secondary spermatocytes, which undergo meiosis to form spermatocytes, which are stored in the epididymis and gradually mature. Eggs, generally in the embryonic period, the female ovary already exists in the embryo, after birth a large number of eggs gradually formed, a large number of oocytes are wrapped in the primordial follicle, in the sex hormone stimulation, the primordial follicle gradually matured, and discharged to the pelvic cavity by the umbilical end of the fallopian tube picked up into the fallopian tube to meet with spermatozoa and form a fertilized egg. Sperm comes mainly from the testicular tissue and eggs from the ovaries.