Drawing of a flea done by Robert Hooke & published in Micrographia in 1665. Hooke was curator of experiments at the Royal Microscopical Society of London, which was founded in 1660. He used a compound microscope to view a wide range of specimens, then drew & published the results of his remarkably detailed observations. Some of the illustrations in Micrographia were supposedly down by Christopher Wren, the architect. Hooke is best remembered for his discovery of the fundamental unit of life, the cell, based on his observations of a section of cork. Born in 1635, he died on March 3rd 1703.