Illustration of Lazzaro Spallanzani (1729-1799), Italian biologist. In 1767, Spallanzani's experiments on sealed well-boiled broth, questioned the theory of the spontaneous generation of microbes. He showed that some organisms can live without oxygen; achieved artificial insemination in amphibians, insects and dogs; discovered that bats could fly and hunt even when blinded, and was the first to observe blood passing from arteries to veins in warm-blooded animals. He also studied volcanoes and the digestive system. Illustration published in 1879.