In 2016 the British gynecological charity The Eve Appeal showed 1,000 women a medical drawing of the female reproductive system and asked them to place six labels on it. Forty-four percent could not identify the vagina. Sixty percent could not identify the vulva. Fewer than a third placed all six…

Three studies, 307 women, one pooled figure: a mean labia minora length of 53.23 mm — about 2.10 inches — with a 95% confidence interval running from 43.50 to 62.96 mm. Mean width came in at 18.28 mm (0.72 in), confidence interval 14.93 to 21.64 mm.

Six weeks after fertilization, a human embryo is roughly 1.2 centimetres (0.5 inches) from crown to rump, and there is nothing about its lower body that would let anyone tell one from another. There is a ridge of tissue that could become a testis or an ovary. There is a small bud. There are two…

There is a drawer in most large natural history collections that visitors never get to open. It holds bacula — penis bones — sorted by species, labeled in copperplate, and quietly astonishing. A weasel's is a hooked splinter. A raccoon's looks like a small crochet needle.

Ask most adults to point to the vagina on a diagram and a good number will point at the outside of the body. It is one of the most common naming errors in everyday English, and it is worth correcting first, because almost everything else in female external anatomy is built on that distinction.

Latin had a word for acorn: glans. It covered nuts generally, and Latin lexicons such as Lewis and Short record the same word applied to the lead bullets Roman armies fired from slings — cast in the same tapered, rounded shape.

In 2015, researchers at King's College London pooled measurements from up to 15,521 men to build the reference nomograms still quoted in nearly every article about penile size. Buried in the methods section is a decision that says more about anatomical shape than the results ever could: the…

At six weeks in, the blueprint is identical after fertilization, a human embryo is roughly 10 to 14 mm long (about 0.4 to 0.6 in) — the length of a coffee bean. Along the back wall of its abdominal cavity sit two small ridges of tissue.

Humans are odd apes. But the popular version of how we are odd gets the details wrong in ways that are more interesting than the myth.