Fungi are neither plants nor animals — a separate way of living

Sheldrake opens by dismantling the common assumption that fungi are just odd plants. Genetically and biologically, fungi form their own kingdom, arguably closer in some respects to animals than to plants — they can't photosynthesize, and like animals they must consume organic material to survive, though they do so by growing into and through their food and secreting digestive enzymes rather than eating in any conventional sense.

A fungus's basic living unit is the hypha, a thread-like filament that grows by extending at its tip, branching and fusing with other hyphae to form a network called a mycelium. This growth-by-extension is radically different from how plants or animals build bodies, and it's key to understanding much of what follows in the book: fungi don't grow as discrete, bounded organisms so much as expanding, exploratory networks.

Sheldrake frames this categorical strangeness as the reason fungi have been so persistently overlooked in biology — they don't fit neatly into either of the two kingdoms most naturally observed and studied by humans.

Takeaway: fungi represent a genuinely third way of being alive, distinct from both the plant and animal models most people default to.