From the text...'This paper deals with certain fragments of carbon and interprets them as fossil charcoal produced by fire. This is no new idea; it was warmly put forward and warmly opposed a century ago, but of late interest has died because of lack of fresh evidence. Such fragments are often abundant and were once called 'mineral charcoal' or 'mother of coal', but Stopes introduced the French word 'fusain' in her work on coal petrology, and it is now used internationally. The fullest recent discussion of the origin of fusain is edited by Stützer, 1929 (who considers it the product of wet decay). There are references to it in the books on the origin of coal, e.g. Stützer & Noe (1949) and Francis (1954). In this paper I do not deal with fusain in general but merely such fusain which I myself have studied in both field and laboratory. I try to show that it resembles recent charcoal produced in forest fire or experimentally, but I cannot compare it with fusain produced by wet decay at ordinary temperatures because I have never seen any. I merely mention evidence that forest fire can be caused by lightning and then allude to the ecological possibilities of early fires. I have studied fusain in three flora only, namely: (1) E. Greenland at latitude 70º N. A large delta formed during Rhaeti and Lower Liassic (basal Jurassic) time; (2) N. Yorkshire at latitude 54º N. A large delta formed during Lower Oolitic (Middle Jurassic) time; (3) S. Wales (near Bridgend,Glamorgan) at latitude 51º 30' N. Sediments of Rhaetic or basal Liassic age filling fissures in Carboniferous Limestone.....The ecological significance of early forest fire. I doubt whether fire in the early Mesozoic would have much effect today, but the ecologist would be concerned if fire were widespread and recurrent in the Tertiary. Fusain has been described from the Tertiary brown coals, and has indeed been taken as evidence of fire but as I have never studied Tertiary plants I prefer to express no opinion about the strenth of the Tertiary evidence for fire. Let us then imagine the same sort of evidence exists in the Tertiary as in the three Mesozoic floras dealt with here. We would conclude that widespread fires occurred at varying intervals according to local conditions. If occurring at intervals of a few centuries they might not change the forest climax, but they would destroy great patches of young or mature forest and provide a home for the animals and plants of open ground or younger stages in the forest succession. The life of such organisms may be precarious, depending on the chances of distribution to new ground as the old areas become unsuitable, but it should be safer than in the relatively minute areas of bare ground in climax forest. It would help us to understand the origin of the vast number of species which today seem to depend on fire; they may have already evolved in strength and have been ready to seize the increased opportunities offered by man.'