: Micropropagated Conference pear plantlets grown in solid Lepoivre-Quorin medium. In vitro test culture tubes used for the study of bacterial and fungal interactions. Courtesy of Emilio Montesinos, University of Girona, Spain. See article by E. Montesinos, this issue, pp. 245–252, on “Development, registration and commercialization of microbial pesticides for plant protection”.

Upper left: Three-dimensional reconstruction of the Infectious Bursal Disease Virus (IBDV), from chicken, obtained by image processing from cryo-electron micrographs of purified virions. The resolution is 2.8 nm. Authors: José Ruiz Caston, Francisco Rodríguez and José L. Carrascosa, National Center for Biotechnology, CSIC-UAM, Madrid, Spain. (Magnification, ca. 1,300,000×)

Upper right: The bacterial community at the sediment–water interface of a stratified lake (Burke Lake, in the Rose Lake recreation area, near East Lansing, Michigan). Phase micrograph by Douglas E. Caldwell, University of Saskatchewan, Canada. (Magnification, ca. 1100×)

Lower left: The wood-digesting symbiotic protist Joenia annectens from the European dry wood-esting termite Kalotermes flavicollis. Phase contrast image by Michael Dolan, University of Massachusetts at Amherst, USA. (Magnification, ca. 3100×)

Lower right: Histoplasma capsulatum FMR6518. Mature macroconidium with club-shaped ornamentation. Scanning electron micrograph by J. Gené and M. J. Figueras, University Rovira Virgili, Reus, Spain. (Magnification, ca. 5300×)