The successful establishment and maintenance of pteridophyte populations requires the co-occurrence of both the gametophyte and the sporophyte life history phases. Yet, most studies of pteridophyte ecology consider only the sporophyte stage (eg. Grime, 1985). While there are a few studies of gametophyte ecology (eg., Cousens, 1988; Duckett, 1985), there is little knowledge of the factors that limit the distribution and abundance of gametophytes. One factor relevant to the gametophyte phase is the earthworm. Modern families of earthworms likely radiated in soils characteristic of angiosperm forests (Satchell, 1983; Bouche, 1983; Piearce, 1989). Lovis (1977) suggests that the modern polypodiaceous ferns radiated in response to ecological changes brought about by the radiation of the angiosperms. Modern genera of earthworms and leptosporangiate ferns evolved during the Tertiary in communities dominated by angiosperms (Lovis, 1977; Bouche, 1983). Earthworms are known to be involved in dispersal of both the seeds of spermatophytes (McRill & Sagar, 1973) and the spores of pteridophytes (Hamilton, 1988). Earthworms may play a particularly important role in bringing buried seeds and spores to the surface and placing them in improved sites for germination (Grant, 1983). Earthworms naturally till the soil, providing increased aeration, increased porosity and a more even distribution of soil nutrients. They also positively influence soil nutrient content by acting as a first step in the decomposition of detritus, and cause an increase in the numbers and diversity among microbial populations in the soil, thereby increasing the rate of decomposition, and increasing nutrient turnover rates (Lee, 1985). Earthworms prey on small pieces of vegetation, fungi, algae, and even other earthworms (Darwin, 1881; Lavelle, 1983; Lee, 1985). The green, surface dwelling gametophytes characteristic of modern ferns would likely make excellent prey for earthworms. As earthworms have been shown to be influential in the gametophyte habitat, an experiment was undertaken to determine if the presence of earthworms influences the germination of spores, gametophyte establishment, and/or gametophyte reproductive success.