Specialised Habitats 207 (i) Fungi of dung and straw heaps 207 (ii) Fungi of bonfire sites 216 (iii) Fungi of bogs and marshes 222 (a) _Sphagnum_ bogs 222 (b) Alder-carrs 226 (iv) Fungi of beds of herbaceous plants 227 (v) Fungi of moss-cushions 230 (vi) Heath and mountain fungi 231 (a) Moorland fungi 231 (b) Mountain fungi & Basidiolichens 236 (vii) Sand-dune fungi 238 (viii) Subterranean fungi 243 (ix) Fungal parasites 246 G. Appendix 249 (i) Species lists of specialised habitats 249 (ii) Glossary 260 (iii) Simple experiments with Fairy-rings 264 (iv) Development of the Agaric fruit-body 266 (v) References 269 H. Index 271 _Cover transparency supplied by John Markham, F. R. P. S., F. Z. S._ INTRODUCTION The term larger fungus refers to any fungus whose study does not necessarily require more than a low-powered lens to see most of the important morphological features. Using such a term cuts across the existing scientific classification, for it includes the more obvious fungi bearing their spores on specialised reproductive cells called basidia, fig. 5, and a few of those whose spores are produced inside specialised reproductive cells called asci. The term is useful, however, even though it embraces a whole host of unrelated groups of fungi; it includes the polypores, fairy-clubs, hedgehog-fungi, puff-balls and elf-cups, as well as the more familiar mushrooms and toadstools--or puddockstools as they are often called in Scotland. Specimens of all these groups will find their way some time into the collecting baskets of the naturalist when he is out fungus-picking, along with probably a few jelly-fungi and less frequently one or two species of the rather more distantly related group, the morels. The biggest proportion of the finds, however, on any one collecting day in the autumn, when the larger fungi are in their greatest numbers, will be of the mushrooms and toadstools; these are, collectively, more correctly called the agarics.