MOST science students are familiar with the terms malphigian layer of the skin, malphigian corpuscles of the kidney and the spleen.The ingenious scientist who was recognised as the founder of microscopic anatomy was Marcello Malpighi — a peace-loving man, ever ready to sacrifice his own pleasures for others and totally dedicated to his work.

Marcello was born in 1628. He was the oldest child in the family of eight children. At the age of 21 he lost both his parents. He readily took over the responsibility of his brothers and sisters. He postponed his own education till all matters were settled. At the age of 23, he entered the medical school at the University of Bologna. He decided to be a physician so that he could be of some use to humanity. At the university he met Massari, a professor of anatomy. Malpighi helped him with dissection and was thoroughly inspired by him. He even married Massari’s younger sister and the marriage worked out to be a very happy one.

In 1653, Malpighi received his MD from Bologna. In 1656, he became a professor of theoretical medicine at the University of Pisa. There he met Borelli who had been a pupil of Galileo. Galileo had taught Borelli how to grind and how to use lenses to see the invisible. Under Borelli’s guidance, Malpighi studied animal tissues under the microscope. Together, they published a paper on the structure of the heart muscle. In 1659, Malpighi returned to his family at Bologna, where he taught anatomy and also continued the study of tissues.

Further studies conducted by Malpighi helped him discover the presence of corpuscles in the blood. His reputation as a scientist spread. An old family enmity disturbed his peace of mind and he left for Messina, as it was against his nature to fight back and hurt anyone. He was invited to London to report his discoveries of capillaries and blood corpuscles.

In 1668, Malpighi was elected as an honorary member of the Royal Society. In 1669, he reported to the Royal Society the structure and metamorphosis of the silkworm. It was the first complete description of internal anatomy of an invertebrate. It was also the first description of the respiratory, digestive and excretory system of an insect. Entomologists still refer to the tubular excretory organ as Malpighian tubules.

Later, Malpighi began studying plant life. He made various observations and suggested that green leaves manufacture food for the plant. He made a tremendous contribution in the study of the embryo of a chick. His description of the skin, the taste organs of the tongue, the liver and bile production, the fibre tracts of the spinal cord and the grey matter of the brain was brilliant. In 1691, Malpighi went to Rome and became the personal physician of Innocent XII. He died in 1694, leaving the door open to new fields of scientific study.

Microscopic anatomy

THE application of magnifying glasses and compound microscopes to biological studies in the second half of the 17th century was the most important factor in the subsequent development of anatomical research. Primitive early microscopes enabled Marcello Malpighi to discover the system of tiny capillaries connecting the arterial and venous networks, Robert Hooke to first observe the small compartments in plants that he called "cells," and Antonie van Leeuwenhoek to observe muscle fibres and spermatozoa. From then on attention gradually shifted from the identification and understanding of bodily structures visible to the naked eye to those of microscopic size.

The use of the microscope in discovering minute, previously unknown features was pursued on a more systematic basis in the 18th century, but progress tended to be slow until technical improvements in the compound microscope itself, beginning in the 1830s with the gradual development of achromatic lenses, greatly increased that instrument’s resolving power. These technical advances enabled Matthias Jakob Schleiden and Theodor Schwann to recognise in 1838-39 that the cell is the fundamental unit of organisation in all living things. The need for thinner, more transparent tissue specimens for study under the light microscope stimulated the development of improved methods of dissection, notably machines called microtomes that can slice specimens into extremely thin sections. In order to better distinguish the details in these sections, synthetic dyes were used to stain tissues with different colours. Thin sections and staining had become standard tools for microscopic anatomists by the late 19th century. The field of cytology, which is the study of cells, and that of histology, which is the study of tissue organisation from the cellular level up, both arose in the 19th century with the data and techniques of microscopic anatomy as their basis.

In the 20th century anatomists tended to scrutinise tinier and tinier units of structure as new technologies enabled them to discern details far beyond the limits of resolution of light microscopes. These advances were made possible by the electron microscope, which stimulated an enormous amount of research on subcellular structures beginning in the 1950s and became the prime tool of anatomical research. About the same time, the use of X-ray diffraction for studying the structures of many types of molecules present in living things gave rise to the new sub-speciality of molecular anatomy.