Reinier (also sometimes spelled Regnier) de Graaf (
1641-
1673) was a
Dutch physician who made important discoveries studying the
pancreas and
mammalian reproductive organs, the most important of which was the discovery of the
egg…more or less.
De Graaf studied medicine at the
University of Angers in
France, graduating in
1665. He returned to the Netherlands, settling in
Delft in
1667, where he established a medical practice and would spend the rest of his life.
In
1672, he was using a primitive
microscope to study
ovaries. Incidentally, de Graaf was the first to call them ovaries. He discovered what he thought were eggs, but what he was actually looking at were the protective sacs of fluid in the wall of the ovary where the eggs grow, which would be later called
graafian follicles.
Regardless of what he actually saw, it transformed current theories of reproduction. Previously, it was thought that
menstrual fluid formed the
fetus – instant baby, just add
semen! Now, de Graaf’s theory that the eggs traveled down the
fallopian tubes to the
womb challenged the prevailing view. But the male medical establishment refused to believe that women contributed to the organizational formation of the baby, and asserted that the egg merely contained and nurtured the sperm. Soon enough though, theories were proposed that gave the egg all the credit. It would be another century before
Lazzaro Spallanzani put one and one together.