Acrochaete repens Pringsh. and Bolbocoleon piliferum Pringsh. endophytic in Chorda filum (L.) Stackh. are shown to be more variable in form than indicated by the original descriptions. Plants are present all year at Rhosneigr, Anglesey, North Wales, reaching their peak development at the end of the year and contributing to the annual breakdown and disappearance of C. filum sporophytes. Both species were isolated in culture. Reproductive bodies of A. repens germinated to produce a single generation of plants. Starting from a cushion of cells, an extensive upright system of filaments was produced, bearing hairs and sporangia containing non-viable swarmers. Two self-replicating, apparently asexual generations of B. piliferum were obtained. Quadriflagellate, non-pairing zoospores germinated into two forms of the parent type, one 'normal' with hair cells and hairs, the other 'reduced' and highly reproductive, with few hair cells or hairs. In both forms the essential characteristics of the species were preserved. Zoospores from the first generation were of the parent type, germinating into culture forms of either type. Culture plants of A. repens and B. piliferum ultimately developed into extensive filamentous systems scarcely distinguishable from one another. Since the two species occur in close association both in the field and in culture, the possibility that they may be parts of the life history of a single taxon cannot be ruled out.
Life History of the First Generation of the Dermestid Beetle, Thaumaglossa rufocapillata