The fungus Aspergillus fumigatus is a ubiquitous soil organism, the spores of which become airborne and are of a size which makes them readily inhalable. It is an organism of limited interest to occupational physicians, but is one of the agents responsible for farmer's lung while its relativeAspergillus niger has important uses in biotechnology and may be a cause of occupational asthma among workers.

This book is a compilation of essays, mainly on the molecular biology and mechanisms relating to the organism's relatively uncommon role as a human pathogen. The individual essays are of interest to a microbiologist and summarise the large amount of fundamental research into the organism. But there is a lack of coordination between the chapters so that each is read as a separate essay unconnected to the others and one gets the impression that the wood has been missed because of all the interesting trees. A pity, because the organism is of interest to a wide range of scientists and interactions between different disciplines will show much of interest, relating for example to the mechanisms of phagocytosis and cell motility. The reasonAspergillus fumigatus resists phagocytosis is probably that it prefers to live on other soil organisms rather than to be their food.

The clinical sections add little to what is to be found in standard textbooks while the more basic biological sections shed little light on the central medical issue concerning this interesting organism—why it among all the airborne fungal spores causes such a curious variety of human and animal diseases. In the preface it is stated that this question has not yet been answered—perhaps not, but I think that a decade ago we got closer than the authors are aware (Lancet 1989;i:893–4, J Med Vet Mycol 1989;27:295–302).