摘要:Histological characteristics of male reproductive organs were observed macrographically and microscopically in Japanese macaques aged 20 years old or more. As the senility proceeded, testicular weight and the diameter of the seminiferous tubules decreased. Likewise, the weights and epithelial heights of the seminal vesicle and prostate gland decreased in old males. Histologically, a proliferation of interstitial tissue was notable in every organ examined. Seminiferous epithelium decreased in height as the age of animal approached thirty years. Similarly, disorder of cellular association and decrease in the number of spermatogenic cells were observed in the seminiferous tubules.