Differential interference contrast (DIC) light micrograph of Caenorhabditis elegans, a soil-dwelling bisexual nematode worm which feeds on bacteria. A tendency to reproduce by self-fertilization (resulting in identical offspring), along with the short time taken to reach maturity, make this tiny worm an ideal subject for genetic research. Scientists have already drawn up a 'wiring diagram' of its nervous system, studied the development of each of its 959 component cells and produced a map of its genes. Attempts are now being made to decode the genetic blueprint of C. elegans, to identify every one of the 100 million letters, or bases, in its genome. Magnification: x325 when printed at 10 centimetres wide at its longest edge.