Dimorphic Pit Connections in the Red Alga Pseudogloiophloea

Pit connections are unusual structures found almost exclusively in the septa of "higher" red algae (Florideophycidae) . Their structure (Myers et al ., 1959; Bouck, 1962; Peyriere, 1963 ; Bishoff, 1965 ; Bisalputra et al ., 1967) and formation (Ramus, 1969 b) have been described with the aid of the electron microscope . Pit connections, at maturity, consist of two structural components : a circular septal aperture and a lenticular plug fitted into the aperture . The plug completely disrupts the cytoplasmic continuity which once existed between adjacent cells (Ramus, 1969 b) . Previously, the mature pit connections of an individual were assumed to be structurally identical. This paper will describe some interesting structural differences found in the red alga Pseudogloiophloea, with the aid of both the light and electron microscopes, and will consider the significance of these differences.