Marcello Malpighi

Lore & Background

Malpighi was born on 10 March 1628 at Crevalcore near Bologna, Italy. He entered the University of Bologna at the age of 17. He studied Aristotelian philosophy and later joined the school of anatomy under Bartolomeo Massari, being one of nine students who met at the home of the master to conduct dissections. He married Francesca, the daughter of Massari, but it was short-lived as she died shortly after. Despite opposition from the university authorities because he was non-Bolognese by birth, in 1653 he was granted doctorates in both medicine and philosophy. In 1656, Ferdinand II of Tuscany invited him to the professorship of theoretical medicine at the University of Pisa, where he began his lifelong friendship with Giovanni Borelli. Family responsibilities and poor health prompted his return in 1659 to the University of Bologna. In 1661 he identified and described the pulmonary and capillary network connecting small arteries with small veins. Malpighi's views evoked increasing controversy and dissent, mainly from envy and lack of understanding on the part of his colleagues.

Reader's Guide

Malpighi's significance lies in his pioneering use of the microscope to reveal structures invisible to the naked eye. He discovered capillaries, completing the circulatory model proposed by William Harvey. His treatise De polypo cordis (1666) was important for understanding blood composition, as well as how blood clots, describing how the form of a blood clot differed in the right against the left sides of the heart. He also discovered that insects do not use lungs to breathe, but small holes in their skin called tracheae. He studied the anatomy of the brain and concluded this organ is a gland, a deduction correct in terms of modern endocrinology because the hypothalamus has hormone-secreting capacity. His study of plants led him to conclude that plants had tubules similar to those he saw in insects like the silkworm, and he observed that when a ring-like portion of bark was removed on a trunk a swelling occurred in the tissues above the ring, correctly interpreting this as growth stimulated by food coming down from the leaves. The Royal Society of London published two volumes of his botanical and zoological works in 1675 and 1679, another edition in 1687, and a supplementary volume in 1697. Malpighi practiced 'rational' medicine, using his knowledge of human anatomy and disease pathology rather than relying on anecdotes or experiences, and he also believed in so-called 'miraculous' or 'supernatural' healing under certain conditions. His legacy endures in numerous anatomical eponyms and the plant family Malpighiaceae.

Did You Know?

• Malpighi was one of the earliest people to observe red blood cells under a microscope, after Jan Swammerdam.
• His treatise De polypo cordis (1666) described how the form of a blood clot differed in the right against the left sides of the heart.
• He discovered that insects do not use lungs to breathe, but small holes in their skin called tracheae.
• Malpighi concluded that the brain is a gland, a deduction later validated by modern endocrinology's recognition of the hypothalamus's hormone-secreting capacity.
• The Royal Society of London published his botanical and zoological works in 1675, 1679, 1687, and a supplementary volume in 1697.

The Microscope as a Window into the Living World

Malpighi's most transformative contribution emerged from his sustained use of the microscope to examine living tissue. He became the first person to see capillaries in animals, revealing the tiny connecting network between arteries and veins that had eluded William Harvey. He was one of the earliest people to observe red blood cells under a microscope, after Jan Swammerdam. His 1666 treatise De polypo cordis advanced understanding of blood composition and clotting, noting how the form of a blood clot differed in the right against the left sides of the heart. Beyond the circulatory system, his microscopic work on insects revealed that they breathe not through lungs but through small holes in their skin called tracheae. He also studied the anatomy of the brain and concluded this organ is a gland, a deduction that aligns with modern endocrinology's recognition of the hypothalamus's hormone-secreting role. These observations collectively earned him the title of founder of microscopical anatomy, histology and father of physiology and embryology.

Plants, Insects, and the Broader Natural World

Malpighi's curiosity extended well beyond human anatomy into the wider biological world. Studying plants with his microscope, he identified tubule-like structures that he compared to those in insects such as the silkworm; he probably saw the stomata, through which plants exchange carbon dioxide with oxygen. His bark-ring experiment was particularly insightful: when a ring-like portion of bark was removed on a trunk, the tissue above the ring swelled, and he correctly attributed this to growth stimulated by food coming down from the leaves being blocked above the ring. His insect work led to the discovery of the Malpighian tubule system of insects. The Royal Society of London published two volumes of his combined botanical and zoological works in 1675 and 1679, with a further edition in 1687 and a supplementary volume in 1697. His Anatome Plantarum, decorated with the engravings of Robert White, was a work he called 'the most elegant format in the whole literate world.' The botanical family Malpighiaceae bears his name in lasting recognition.

A Restless Academic Life Shaped by Rivalry and Curiosity

Malpighi's career was marked by movement between institutions and a persistent tension between teaching and independent research. Born in 1628 at Crevalcore near Bologna, he entered the University of Bologna at seventeen, studying Aristotelian philosophy and joining Bartolomeo Massari's anatomy school, where nine students gathered at the master's home for dissections. He married Massari's daughter Francesca, though the union was brief due to her early death. Despite opposition from university authorities over his non-Bolognese origins, he earned doctorates in medicine and philosophy by 1653. In 1656, Ferdinand II of Tuscany invited him to the professorship of theoretical medicine at the University of Pisa, where he formed a lifelong friendship with the mathematician and naturalist Giovanni Borelli. Poor health and family duties brought him back to Bologna in 1659. He later held a chair at Messina in 1662 and again in 1667, yet he continuously returned to Bologna to practice medicine. His experimental approach drew envy and dissent from colleagues, and his Dialogues against the Peripatetics and Galenists were destroyed when his house burned down. He was invited to correspond with the Royal Society in 1667 by Henry Oldenburg, and became a fellow of the society the next year.

A Legacy Written into the Body Itself

Malpighi's name endures not merely in textbooks but in the very architecture of living organisms. The Malpighian corpuscles and Malpighian pyramids of the kidneys, the Malpighian tubule system of insects, and the splenic lymphoid nodules—often called Malpighian bodies of the spleen—all carry his surname as a permanent marker of his microscopic discoveries. The entire botanical family Malpighiaceae is named in his honor. His 1666 treatise De polypo cordis on blood clots in the heart remains a foundational text for understanding blood composition and clotting. The Royal Society of London, to which he was invited to correspond in 1667 by Henry Oldenburg and elected a fellow the following year, published multiple editions of his collected works across the 1670s and 1680s, with a posthumous volume appearing in 1697. His contributions to microscopical anatomy, histology, physiology, and embryology collectively earned him the title of father of these disciplines, a designation that has persisted for over three centuries. He is buried in the church of Santi Gregorio e Siro in Bologna, where a marble monument with a Latin inscription remembers his 'SUMMUM INGENIUM / INTEGERRIMAM VITAM / FORTEM STRENUAMQUE MENTEM / AUDACEM SALUTARIS ARTIS AMOREM' (great genius, most upright life, strong and vigorous mind, bold love of the healing art).