The Female Conceptacle and Young Sporeling of the Four New Zealand Species of Carpophyllum By Margaret Naylor, Otago University [Read by title before Otago Branch on July 14, 1953; received by Editor July 27, 1953.] Abstract The four New Zealand species of Carpophyllum agree closely in details of conceptacle development, oogonium maturation and early segmentation of the sporeling. The oogonium contents are liberated in an eight nucleate condition and the maturation of the oosphere is completed after extrusion. A mucilaginous stalk formed from the oogonium wall retains the fertilised egg until the rhizoidal system of the sporeling is established. Introduction The genus Carpophyllum is represented in New Zealand by four species—C. elongatum (Dickie) A. & E. S. Gepp, C. flexuosum (Esper) Grev., C. maschalo-carpum (Turn.) Grev. and C. plumosum (Ach. Rich.) J. Ag.—and the variety capillifolium J. Ag. of C. plumosum. The only descriptions of the reproductive structures of these species are those of Delf (1939) and Dawson (1940) who worked in England on preserved material sent from New Zealand. Owing to the restricted nature of their material these accounts are not complete and the present investigation is an attempt to fill in some of these gaps. The C. elongatum was collected from Mokohinau Island, from Cape Brett and from Tapeka Point, Russell, but owing to difficulties involved in collecting from these exposed habitats, the account of this species is still incomplete. The remaining species were collected principally from Castor Bay, Auckland, supplemented by material from Russell. The fixative used throughout was Papenfuss's modification of Karpechenko fluid (Laing, 1941). Sections were cut at 8μ and stained with crystal violet or Heidenhain's iron alum haematoxylin for cytological details and with erythrosin or Delafield's haematoxylin for segmentations of the sporeling. The Conceptacles Early stages of conceptacle development have been described in C. elongatum and C. maschalocarpum by Delf and in C. flexuosum by Dawson and my observations show a similar sequence of divisions in C. plumosum (Text-figs. 1A–C). In all four species only a few, relatively large oogonia develop in each conceptacle. At maturity they occupy almost the entire conceptacle cavity (Text-fig. 1D) and usually become angular as the result of mutual pressure. They are separated by groups of closely appressed moniliform hairs whose cells swell after the release of the oogonium contents and fill the spent conceptacles with pseudoparenchymatous tissue. Dawson found the average number of oogonia in a conceptacle to be nine in C. flexuosum. I find a similar number in C. plumosum and C. elongatum also, but in C. maschalocarpum usually only three or four reach maturity