Anthropology / Everything Human

Surprise! Semen Is Required

Sex

  • Origins

    Not all frogs begin as tadpoles. However, Lazzaro Spallanzani was the first to show that all frogs, dogs, and humans begin growing only if a male contributes his essence to the process.

    Surprise! Semen Is Required

    Reproduction seems so obvious to us now. Even if we don’t know the details, we know about the birds and the bees. For humans and an overwhelming number of other species, both female and male contribute stuff that, together, transmogrifies into babies. These days we take our understanding of the baby-making process so much for granted that it’s amusing to look back at the intellectual struggles of early …

  • Animalia

    The 19th Century anatomist Jones Quain dissected the human testicle, as illustrated by this engraving.

    When Sperm Compete, Nature’s Call Leads to Bigger … Testicles

    [In humans, the testes] are from an inch and a half to two inches long, about an inch and a quarter from the anterior to the posterior border, and nearly an inch from side to side. The weight of each varies from three-quarters of an ounce to an ounce, and the left is often a little the larger of the two. —Quain’s Elements of Anatomy, 1867 Success in …

  • Culture Lab