I was that child who asked “Why is the sky blue?” until I was satisfied with the answer I was given. My mother quickly adapted to my questions; she bought my brother and me a set of encyclopedias and a “how science works” book series along with two dictionaries. She gave us both unlimited access to the public library and encouraged me to bestow some questions on the librarians. We were both encouraged to read anything we wanted, no matter how challenging the material or how questionable in nature the material was deemed by other mothers.
Our mother never stifled our creativity, intelligence or curiosity. Perhaps this is why I still ask questions to this day. I want to know as much as I can about everything that interests me, which is one reason I spend more time reading and researching than watching television.
The other day I was reading a book for some ideas for some Tweets and found information that excited me. I discovered a treasure trove of anatomy-related information about sex and reproduction. I want to share this information because it is just good stuff to know.
The Italian anatomist Gabriel Fallopius was born in 1523 in Modena, Italy, and served as a canon of the cathedral of Modena before returning to the study of medicine. In 1549, Fallopius became a professor of anatomy at the University of Pisa. He performed multitudes of dissections using human cadavers and described his work in the book Observationes anatomicae, which was published in 1561.
Fallopius described many of the major nerves of the head and face as well as the semicircular canals of the inner ear, which control the body’s equilibrium. In his dissection work, Fallopius discovered and described two slender tubes that connect the ovaries to the uterus, but he was unable to determine the exact function of the tubes. Other scientists would eventually discover that fertilization of the egg takes place in these tubes, which are now called the Fallopian tubes in honor of Fallopius.
In my opinion, Fallopius’ greatest works involve his naming several major structures of the female reproductive system. He was enamored with female anatomy and did much work in this area during his dissection research. Fallopius named the vagina, which is Latin for “sheath,” and the placenta, which is Latin for “flat cake.” The placenta is the vascular disk-like organ that connects the embryo to the uterine wall via the umbilical cord.
Fallopius named the clitoris, which is the small, hooded erectile organ located at the upper end of the vulva. He knew the clitoris was extremely sensitive, but he did not know why. A doctor during the 20th century figured out the clitoris is the major organ for female sexual orgasm.
One of Fallopius’ students was an Italian man called Hieronymus Fabricius, who was born in 1537 under the name Geronimo Fabrizio. He studied Greek and Latin languages and philosophy in Padua before engaging in the study of medicine under Fallopius, which is when Fabricius learned, and then exceled at, anatomy and surgery. After Fallopius’ death in 1562, Fabricius became his successor at the University of Padua, becoming the chairs of anatomy and surgery at the school.
Among Fabricius’ greatest achievements include the discovery of how blood circulates in the human body, especially through the veins, and his research on fetuses.
Fabricius was the first known anatomist to perform dissections in an anatomical theatre where students could watch his work in person. Through the dissection of animals, Fabricius investigated the formation of the fetus. In 1586, Fabricius performed a dissection of the uterus and placenta of a pregnant woman. A few years after this, Fabricius began to lecture on the formation of the fetus and provided private lessons on the subject of embryology, which is the branch of biology dealing with the development of an embryo from the fertilization of the ovum, or egg, to the fetus stage.
His publication of two treatises on embryology made important contributions to that field. The treatise written about the Formulation of the Egg and of the Chick was published after his death. Both treatises contained impressive illustrations depicting the uterus and comparative studies of the fetuses of dogs, cats, mice, rabbits, goats, guinea pigs, sheep, cows, horses, pigs, birds, sharks and humans. Fabricius is called “the father of embryology” because he was one of the first to study and illustrate the human uterus.
Another Italian who made remarkable discoveries in the fields of science and reproduction is Lazzaro Spallanzani, who was born in 1729 in Scandiano, Italy. He studied mathematics, philosophy and languages at a Jesuit seminary in Reggio, became a physiologist, was a professor of natural history at the University of Pavia and was the first to describe the basis of sexual reproduction. Interestingly, Spallanzani was a practicing chaste, celibate Roman Catholic priest even when he studied matters of science and taught at university.
In 1779, Spallanzani showed for the first time that physical contact between the male seminal fluid and the female egg was necessary to develop a fetus. Prior to his discovery, most people, including scientists and even Spallanzani himself, believed in “remote fertilization,” in which an egg could be fertilized without direct contact with seminal fluid. It was commonly thought if an egg was exposed to invisible “spermatic vapor” it would then develop into an embryo. Since male vapor could not be seen, its existence was a matter of faith.
Due to his religious beliefs, Spallanzani could not experiment with human sperm, so he primarily used frogs in his experiments. Spallanzani made tiny waterproof taffeta pants and dressed male frogs in these pants. He then released these taffeta-panted male frogs into an area with naked females. The male frogs mounted the females and ejaculated into their pants, giving Spallanzani a supply of frog sperm for use in his experiments on reproduction.
Spallanzani attempted to prove the existence of “spermatic vapor” by attaching freshly laid toad spawn (eggs) into a watch glass and then inverting it over another watch glass containing toad seminal fluid. The belief at the time was that the sperm would migrate through the air to stimulate the eggs. Nothing happened until Spallanzani mixed eggs directly into the seminal fluid; this is when he produced tadpoles and become one of the first scientists to achieve artificial insemination in a laboratory under controlled conditions.
Buoyed by his success with creating tadpoles, Spallanzani masturbated a male dog, then artificially inseminated a female dog, which he had kept in an isolated room separate from the male dog to completely dispel the notion that “spermatic vapor” was responsible for the fertilization of female mammals.
These Italian scientists helped shape our sexual vocabulary and helped define sexual reproduction as we know it today. Scientists from other countries and in other centuries added to the world’s even-changing sexual vocabulary during their own times as well. We will explore some of these greats in future blogs.