Spallanzani, Lazzaro

Spallanzani, Lazzaro (1729-1799), Italian physiologist who was one of the founders of experimental biology.

Born in Scandiano on January 12, 1729, and educated in law at the University of Bologna, Spallanzani turned to logic and metaphysics before he became Professor of Physics at the Universities of Modena and, finally, Pavia (1769), where he conducted most of his experiments. Attacking the theory of spontaneous generation, Spallanzani set up experiments to refute those of the English Roman Catholic priest John Turberville Needham, who had heated and then sealed meat broth in vessels; because micro-organisms were found in the broth when it was later unsealed, Needham believed that this proved that life generates from nonliving matter. By prolonging the heat and more carefully sealing the vessels, however, Spallanzani was able to show that such broths generated no micro-organisms as long as the vessels remained sealed.

Spallanzani later broadened his experimental work. He investigated the ability of many lower animals to regenerate parts, and in a transplant experiment he successfully grafted the head of one snail on to the body of another. He studied the circulation of blood through the lungs and experimented on digestive juices, which, he observed, were specialized for digesting different foods. Attempting to discover what part of the semen was essential for generation, he filtered samples from amphibians and discovered that the higher the filtration, the less likely was the development of an egg. Although Spallanzani was far from understanding the role of spermatozoa and believed them to be parasites, he was able to artificially inseminate a dog and several lower animals through his careful experiments. In his last experiments he tried to demonstrate how body tissues convert what is now known as oxygen to carbon dioxide. Spallanzani died in Pavia on February 11, 1799.