Tree wood anatomy by van Leeuwenhoek, 1680

Tree wood anatomy by van Leeuwenhoek, described in a letter of 1680. The anatomy of internal vessels in wood from oak, beech and elm trees are shown here, including oak tree rings (top left). A piece of elm is at bottom left, with a piece of oak at centre, and a piece of beech at far right. Dutch scientist Antonie van Leeuwenhoek (1632-1723) built his own microscopes and was able to study the natural world in greater detail than was previously possible. His observations included protozoa, bacteria, insects, plants, minerals, blood cells, and sperm. His earliest observations were published in 1673, and over the next 50 years he self-published and wrote hundreds of letters to scientists and learned societies detailing his discoveries. This page is from Letter 29 to Robert Hooke (written 12 January 1680) and later published in 'Ontledingen en Ontdekkingen van Levende Dierkens' (1696).