The issue of Mycological Research News pays tribute to R. W. G. Dennis on the occasion of his ninetieth birthday. The importance of permanent microscopic mounts is also featured.

This month's Mycological Research includes the text of the British Mycological Society's Benefactors' Lecture presented by J. D. Rogers in April and which concerns tropical Xylariaceae. In addition, studies of fungi growing in the most radioactive situation in which they have previously been investigated, inside the damaged reactor building at Chernobyl, are reported.

Molecular studies included concern the detection of Tricholoma matsutake, and variation in isolates of Scytalidium thermophilum. Effects of high frequency aneuploidy mutants in Aspergillus nidulans have been examined. Sclertotial inhibitors have been tested for effects against Coniothyrium mintans, and the responses of VA-mycorrhizal fungi to different exudates compared. Mangrove forest plant endophytes, and fungi decaying camphor trees (Ocotea usambarensis), have been isolated and studied in vitro.

Ultrastructural studies on septal pore caps in genera of Hymenochaetaceae and Lachnocladiaceae, and on conidiogenesis in Cercosporella ugandensis and Pseudocercspora musae are presented. The ecology and world distribution of Barbeyella minutisma is also documented.

Two new species are described: Leptographium sibiricum and Melanconiopsis microspora spp. nov.