This gallery depicts specimens of the roundworm Caenorhabditis elegans, which is transparent and about a millimetre long; its internal structures can be seen clearly through its skin. Some images, taken under simple white light, show the insides of individual worms’ heads. Some images, taken at much higher magnifications, narrow in on individual brain cells of living animals. These long-tailed neurons have been genetically instructed to produce fluorescent material, setting them apart under laser light from their numerous but here-invisible neighbour cells. Each image is a flattened composite of multiple photographs; none represents any real living instant. In some images, movement between instants creates blurs and double-vision. Sometimes, other cells and structures appear by surprise, having absorbed fluorescent matter unintended for them, or by their own fluorescent properties.