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.

Every society has rules about the menstruating body. What varies — enormously — is what those rules say, who they bind, and what they are understood to accomplish.

In the spring of 1904, on a farm called Rällinge in the Swedish province of Södermanland, a twelve-year-old boy turned up a small bronze man in a potato field. The figure sits cross-legged, wears a pointed cap, tugs at a pointed beard, and has an unmistakable erection. He is seven centimetres tall…

In 1810 an English officer of the East India Company named Edward Moor published The Hindu Pantheon, a compendium of Indian religious imagery assembled for a European readership. Among the plates was a smooth, rounded stone column set into a lipped circular base. Moor described it plainly as a…

In February 1838, a young officer of the Bengal Engineers named T. S. Burt left his assigned route in central India because the men carrying his palanquin told him there was something worth seeing in the forest. What he found, and reported later that year to the Asiatic Society of Bengal, was a…