91色情片

Why is the scrotum so wrinkly?

Neil Smith, By email, no address supplied

We pay 拢25 for every answer published in New Scientist. To answer this question 鈥� or ask a new one 鈥� visit newscientist.com/lastword. Terms and conditions apply.

This article appeared in print under the headline 鈥淣utty question鈥�