Lazzaro Spallanzani (1729-1799), Italian biologist, 19th century illustration. In 1767, Spallanzani's experiments on sealed, well-boiled broth, questioned the theory of the spontaneous generation of microbes. Spallanzani also showed that some organisms can live without oxygen. He achieved artificial insemination in amphibians, insects and dogs. He discovered that bats could fly and hunt even when blinded. Spallanzani was the first to observe blood passing from arteries to veins in warm-blooded animals.