The Dutch naturalist and microscopist Anton van Leeuwenhoek (1632-1723), using simple microscopes of his own making, discovered bacteria, protozoa, spermatozoa, rotifers, Hydra and Volvox, and also parthenogenesis in aphids.

Anton van Leeuwenhoek was born on Oct. 24, 1632, at Delft. His schooling was informal, probably including some mathematics and physical sciences but no languages. At the age of 16 he was sent to Amsterdam to become an apprentice at a linendraper's shop where he remained for about 6 years.

In 1654 Van Leeuwenhoek returned to Delft and married Barbara de Mey, who was to bear him five children. He bought a house and shop and set up in business as a draper. He remained there for the rest of his life. His wife died in 1666 and in 1671 he remarried; his second wife bore him one child.

In 1660 Van Leeuwenhoek was appointed chamberlain to the sheriffs of Delft, an office which he held for...