Studies on the Epidermis of Temnocephala Vii.* The Basal Region, with Comments on 'Membrane Flow'

Abstract

Tubular infoldings of the plasmalemma, and other basal structures in the epidermis of Temnocephala novaezealandiae, are described. At times, the tubular invaginations are greatly elaborated, resulting in a considerably increased plasmalemmal area; also, complex lateral interdigitations occur at the boundaries of the differentiated syncytial epithelia. Many mitochondria are associated with the elaborated membrane. These modifications suggest an enhanced ion transport across the epidermis, and the epidermis is assumed to function in combination with the protonephridial tubules in ionic regulation. Other cytoplasmic structures are correlated with the enhanced plasma membrane, indicating possible pathways of membraneogenesis. Return to the normal epidermal cytomorphology evidently entails a large-scale disassembly of plasma membranes.