Mar 102019

Today is the birthday (1628) of Marcello Malpighi, an Italian biologist and physician, who is sometimes referred to as the “father of microscopical anatomy, histology, physiology and embryology”. Malpighi was born in Crevalcore near Bologna, son of well-to-do parents. He studied a variety of subjects including Aristotelian philosophy, physics, and medicine at the University of Bologna, and took positions in both Bologna and Pisa teaching philosophy and physics before settling to the study of anatomy in 1660.

Although he conducted some of his studies using vivisection and others through the dissection of corpses, his most productive efforts appear to have been based on the use of the microscope. Because of this work, many microscopic anatomical structures are named after Malpighi, including a skin layer (Malpighi layer) and two different Malpighian corpuscles in the kidneys and the spleen, as well as the Malpighian tubules in the excretory system of insects. Although a Dutch spectacle maker created the compound lens and inserted it in a microscope around the turn of the 17th century, and Galileo had applied the principle of the compound lens to the making of his microscope patented in 1609, its possibilities as a microscope had remained unexploited for half a century, until Robert Hooke improved the instrument ( ). Following this, Malpighi, Hooke, and two other early investigators associated with the Royal Society, Nehemiah Grew and Antoine van Leeuwenhoek were fortunate to have a virtually untried tool in their hands as they began their investigations.

Working on frogs and extrapolating to humans, Malpighi demonstrated the structure of the lungs, previously thought to be a homogeneous mass of flesh, and he offered an explanation for how air and blood mixed in the lungs. Malpighi also used the microscope for his studies of the skin, kidneys, and liver. For example, after he dissected a black male, Malpighi made some groundbreaking headway into the discovery of the origin of black skin. He found that the black pigment was associated with a layer of mucus just beneath the skin. Malpighi seems to have been the first author to have made detailed drawings of individual organs of flowers. In his Anatome plantarum is a longitudinal section of a flower of Nigella (his Melanthi, literally, honey-flower) with details of the nectariferous organs. He adds that it is strange that nature has produced on the leaves of the flower shell-like organs in which honey is produced.

Malpighi had success in tracing the ontogeny of plant organs, and the serial development of the shoot. He specialized in seedling development, and in 1679, he published a volume containing a series of exquisitely drawn and engraved images of the stages of development of Leguminosae (beans) and Cucurbitaceae (squash, melons). Later, he published material depicting the development of the date palm. Linnaeus named the genus Malpighia in honor of Malpighi’s work with plants; Malpighia is the type genus for the Malpighiaceae, a family of tropical and subtropical flowering plants.

Because Malpighi was concerned with teratology (the scientific study of the visible conditions caused by the interruption or alteration of normal development) he expressed grave misgivings about the view of his contemporaries that the galls of trees and herbs gave birth to insects. He conjectured (correctly) that the creatures in question arose from eggs previously laid in the plant tissue. Malpighi’s investigations of the lifecycle of plants and animals led him into the topic of reproduction. He created detailed drawings of his studies of chick embryo development, seed development in plants (such as the lemon tree), and the transformation of caterpillars into insects. His discoveries helped to illuminate philosophical arguments surrounding the topics of emboîtment, pre-existence, preformation, epigenesis, and metamorphosis.

In 1691 pope Innocent XII invited him to Rome as papal physician. He taught medicine in the Papal Medical School and wrote a long treatise about his studies which he donated to the Royal Society of London.

Marcello Malpighi died of “apoplexy” (probably stroke) in Rome on 29th September 1694, at the age of 66. In accordance with his wishes, an autopsy was performed. He is buried in the church of the Santi Gregorio e Siro, in Bologna, where nowadays can be seen a marble monument to the scientist with an inscription in Latin remembering – among other things – his “SUMMUM INGENIUM / INTEGERRIMAM VITAM / FORTEM STRENUAMQUE MENTEM / AUDACEM SALUTARIS ARTIS AMOREM” (great genius, honest life, strong and tough mind, daring love for the medical art).

Given Malpighi’s studies of Leguminosae and Cucurbitaceae here is a recipe for an Italian bean and squash soup.

Tuscan Bean and Squash Soup


1 lb dried borlotti beans
3 quarts beef stock
½ cup chopped canned tomatoes
2 garlic cloves, peeled and sliced
¼ cup chopped celery leaves
dried oregano
½ cup extra-virgin olive oil
1 medium onion, peeled and chopped
2 lb butternut squash, peeled and cut into 1-inch chunks
crushed red pepper


Soak the beans overnight.

Drain and rinse the beans, then transfer them to a stock pot. Cover with stock and bring to a simmer over moderate heat. Cook the beans until almost tender, about 1 hour. Add the tomatoes, garlic, celery leaves, oregano to taste, and ¼ cup of the olive oil. Season to taste with salt. Continue cooking until the beans are very tender, about 1 to 1 ½ hours longer.

Meanwhile, in a large skillet, heat the remaining ¼ cup of olive oil. Add the onion and cook over medium heat until softened but not browned. Add the squash and 1 cup of water, cover and simmer over low heat until the squash is barely tender, about 10 minutes.

When the beans are fully cooked, stir in the squash mixture. Season crushed red pepper to taste and simmer for 5 minutes. Serve with crusty bread.