John is a Reader in the School. His initial interest in gerontology and, specifically, in the physiosclerosis of ageing mammalian soft-tissues led to a commitment to electron probe X-ray microanalysis (EPXMA) and associated cryopreparative procedures. This work helped project the Cardiff Laboratory, directed at the time by Professor David Erasmus, to the forefront of low-temperature analytical microscopy, and led to a period of secondment for John as acting Director of Electron Microscopy at the University of Oslo. A desire to exploit the high resolution capabilities of EPXMA to enhance understanding of the cellular physiology of biomineralization led to the exploration of the earthworm calciferous gland as a model system. Earthworms continue to be the main focus of John’s research effort, but the approach to their biology has diversified. Terrestrial ecotoxicology is the dominant current research theme.