Myxomycetes of the Forest: An exploration of the hidden world of the Myxomycetes, or Slime Moulds

Myxomycetes, also known as slime moulds, represent a fascinating and often overlooked group of organisms. Despite their name, slime moulds are neither fungi nor animals but belong to a distinct group within the kingdom Protista. Their strange and mesmerizing life cycles, which include both single-celled and multicellular stages, have made them subjects of intrigue and study for both biologists and nature enthusiasts. Almost microscopic in size, they have a delicate and intricate structure. Slime moulds depend on suitable conditions to grow and reproduce, moisture being the crucial requirement, but they can be found from the tropics to the polar regions, and from deserts to mountain tops, even developing in the cores of desert succulents or beneath lying snow.

John Holden has studied slime moulds in some detail in the Forest of Dean, an area whose warm and humid climate has resulted in variety of damp shady habitats that are rich in organic matter. These are almost ideal conditions for slime moulds to thrive, thereby providing the author with an opportunity to study a wealth of different types in one locality. In his explorations, he has compiled accounts of nearly 100 species, together with photographs taken in both the field and under the microscope.

This work is admirable in many ways. There is a paucity of books to help those wishing to start studying slime moulds and develop their field skills. The first part of this book provides an excellent introductory guide to basic biology, ecology, collection and identification, supported by full colour photos with relevant examples to illustrate key points in the text. The writing is clear, engaging and with sufficient detail to aid the reader rather than overwhelming them. The main part of the book constitutes the species accounts, which make no claim to be complete, but illustrate many of the species that author has encountered when searching the Forest.  At the start of the accounts there is a list of the principal genera of Myxomycetes along with a glossary of terms used. The species entries follow the order indicated in the list. There is also an index of species at the rear of the book. Of particular note, each account includes several high-resolution photographs of key features and stages in the life cycle of the species; that is the most visible and indicative ones, such as spores and associated structures.

Although there are no keys, the quality of the photographs and distinctive differences between families compensates for this. The introductory section provides guidance here.

This is a useful and interesting contribution to an understudied but important phylum of fungus-like organisms. Slime moulds are vital components of ecosystems, contributing to nutrient recycling, soil health, and the regulation of microbial populations. They also serve as model organisms for scientific research, providing insights into cell biology, behaviour, and decision-making. Their unique properties make them valuable to both ecological studies, and technology development with for example a potential as bio-indicators of climate change, and biocontrol of pests.