Alexander Monro, secundus Biography

Three generations of Alexander Monros were professors of anatomy at the University of Edinburgh in unbroken succession from 1720 to 1846. All three contributed immeasurably toward making the medical school at Edinburgh among the world's best of its time. The subject of this article is called Monro secundus to distinguish him from his father, Alexander Monro primus (1697-1767), and his son, Alexander Monro tertius (1773-1859). Monro secundus, the greatest of the three, is chiefly remembered for discovering and accurately describing the foramen interventriculare, or "foramen of Monro," an important passage connecting the lateral and third ventricles of the brain. Knowledge of the communicative function of the foramen of Monro became crucial for the new science of neuroradiology early in the twentieth century because, for neurosurgeons like Walter Dandy (1886-1946), it paved the way for useful neurological diagnostic techniques such as pneumoventriculography, which injects air as an x-ray contrast medium directly into the ventricles.

Monro secundus was early groomed to succeed his already famous father. He began studying anatomy at the university under his father's tutelage when he was only eleven. By 1753, he was handling the student overflow from his father's popular classes. In 1755, he received his Edinburgh M.D. with a thesis on the testicles and semen. Unlike most medical doctoral dissertations of that time, which were only restatements of previous knowledge, his contained original research.

For the next two years, Monro traveled to the most prominent medical and surgical research centers of northern Europe to study under the best anatomists of the day, William Hunter (1718-1783) in London, Johann Friedrich Meckel (1714-1774) in Berlin, and Bernhard Siegfried Albinus (1697-1770) in Leiden. Back in Edinburgh in 1757, he assisted his father, substitute taught for him during his illnesses, and after 1758, co-taught the classes. He had already assumed the main duties of the anatomy professorship long before he took it over completely upon his father's death in 1767. In 1798, Edinburgh named him and his son, Monro tertius, co-professors of anatomy. They shared the position until Monro secundus retired in 1808.

Monro was friendly and gregarious but argumentative, polemical, and quite critical of other anatomists. In 1770, he savagely attacked the ideas of William Hewson (1739-1774) on pneumothorax and lymphatics. In 1794, he fought publicly with Gilbert Blane (1749-1834) about the function of oblique muscle fibers.

Besides his polemics and several minor works on anatomy, Monro wrote three major anatomical treatises: Observations on the Structure and Functions of the Nervous System (1783), which introduced the foramen of Monro; The Structure and Physiology of Fishes Explained and Compared with Those of Man and Other Animals (1785), which became a standard textbook on comparative anatomy; and A Description of All the Bursae Mucosae of the Human Body (1788), his most original investigation.