Swammerdam
was a Dutch doctor, naturalist and microscopist.
He neglected his medical practice to investigate
the life history of insects and the anatomy of
mayflies, frogs and bees. He advanced the study of the
human circulatory system and was the first to describe
red blood corpuscles (1658). He studied movements of
heart, lungs and muscles. His work was published after
his death under the title The Bible of
Nature.