Ajmani M L, Jain S P, Saxena S K
Anthropol Anz. 1985 Jun;43(2):179-86.
Five basic measurements of the male external genitalia were studied in 320 healthy male medical students belonging to the various parts of Nigeria (West Africa). Their ages range from 17 to 23 years. The measurements were as follows: average length of the penis (81.6 +/- 0.94 mm); circumference of the penis (88.3 +/- 0.02 mm); circumference of the scrotum (212.6 +/- 2.48 mm); length of right testis (46.8 +/- 0.54 mm); width of right testis (32.4 +/- 0.37 mm); length of left testis (46.0 +/- 0.53 mm); and width of left testis (31.4 +/- 0.36 mm). The size of the genitalia increases with the increase in age in younger year groups. The adult stages of genitalia development are reached at the age of 21 years in 89.0% of the individuals. The growth of the genitalia is continued with the increasing height and weight, but this growth slows down after attaining a definite height and weight.
对来自尼日利亚（西非）各地的320名健康男性医学生的男性外生殖器进行了五项基本测量。他们的年龄在17至23岁之间。测量结果如下：阴茎平均长度（81.6 +/- 0.94毫米）；阴茎周长（88.3 +/- 0.02毫米）；阴囊周长（212.6 +/- 2.48毫米）；右侧睾丸长度（46.8 +/- 0.54毫米）；右侧睾丸宽度（32.4 +/- 0.37毫米）；左侧睾丸长度（46.0 +/- 0.53毫米）；左侧睾丸宽度（31.4 +/- 0.36毫米）。在较年轻的年龄组中，生殖器的大小随着年龄的增长而增加。89.0%的个体在21岁时达到生殖器发育的成年阶段。生殖器的生长随着身高和体重的增加而持续，但在达到一定的身高和体重后，这种生长会减缓。
