Images Dated 6th June 2003

Art of Diatom algae (from Ernst Haeckel)

Diatoms. Computer-enhanced engraving of assorted species of diatom. Diatoms are a group of single- celled algae. The two main morphological types of diatom are represented here: pennate (rod-shaped) and centric (rounded). A characteristic feature of diatoms is their intricately patterned, glass-like cell wall, or frustule. The frustule consists of two halves which fit together like the lid and bottom of a box. It is often decorated with rows of tiny holes, known as striae. Diatoms form an important part of the floating plankton in the marine and freshwater food chains. Engraving taken from Ernst Haeckel's famous treatise: "Art Forms of Nature" (1904)

© MEHAU KULYK/SCIENCE PHOTO LIBRARY

Wilhelm Roentgen, German physicist

Illustrtion of the German experimental physicist Wilhelm Konrad Roentgen, 1845-1923, discoverer of X-rays. While using a discharge tube (in which an electric discharge is passed through a gas at low pressure) in a darkened room, he noticed that a card coated with barium platinocyanide glowed when the tube was switched on. The effect was not blocked by an intervening wall, or even a thin sheet of metal. Roentgen termed this newly discovered phenomenon X-ray radiation, & suggested that it consisted of electromagnetic rays with a shorter wavelength than light. He was awarded the first Nobel Prize for physics in 1901. Illustrated by the artist Bill Sanderson 1995

© BILL SANDERSON/SCIENCE PHOTO LIBRARY

Fern branches

Fern fronds. Fern fronds are tightly coiled when young, unwinding the coil as they expand. Ferns are spore-bearing plants and the spores are produced on the undersides of fronds in structures called sori which are clusters of spore-producing sacs. More than 7000 species are known. This image was taken in Hawaii

© MAGRATH PHOTOGRAPHY/SCIENCE PHOTO LIBRARY