. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. EPITHELIAL WATER PERMEABILITY IN G. DEMISSA 233 MC. EPS FIGURE 1. Cross-section through the central portion of the mantle ofGenkensia demissa. A. Section from the mantle cavity (MC) to the extrapallial space (EPS) showing the epithelia (epi) on both surfaces with underlying muscle layers (m). The epithelia are separated by connective tissue which encompasses many hemolymph vessels (*), few genital follicles or canals (g), and transverse muscle bundles (tmb) con- necting the two subepithelial muscle layers. Bar = 200 ^m. B. C
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. EPITHELIAL WATER PERMEABILITY IN G. DEMISSA 233 MC. EPS FIGURE 1. Cross-section through the central portion of the mantle ofGenkensia demissa. A. Section from the mantle cavity (MC) to the extrapallial space (EPS) showing the epithelia (epi) on both surfaces with underlying muscle layers (m). The epithelia are separated by connective tissue which encompasses many hemolymph vessels (*), few genital follicles or canals (g), and transverse muscle bundles (tmb) con- necting the two subepithelial muscle layers. Bar = 200 ^m. B. Columnar extrapallial epithelium with thin underlying muscle layer. Bar = 100 ^m. C. Squamous mantle cavity epithelium with thick underlying muscle layer. Fibers from the transverse muscle bundles splay out to join the subepithelial muscle layer (arrows in C2). Bar = 100 with an epithelium underlain by a muscle layer (Fig. 1 A). The extrapallial epithelial cells are much taller than those lining the mantle cavity, but the subepithelial muscle layer associated with the extrapallial space is much thinner than that on the mantle cavity side of the tissue (compare Figs. 1 A, ICi). The bulk of the mantle is occupied by connective tissue in which are found numerous hemolymph vessels and, in these non-reproductive specimens, occasional genital canals (Fig. 1A). Bundles of muscle fibers traverse the mantle joining the two subepithelial muscle layers (Figs. 1A, 1C^). Similar structures have been described for the mantles of other species (Beed- ham, 1958). Diffusional water permeability Preliminary experiments showed that the accumulation of counts in the cold compartment of the diffusion chamber was linear with time for over six hours, indi- cating that the 10 minute equilibration with labelled water was sufficient for attain- ment of a steady-state flux across the tissue. The diffusional water permeabilities of. Please note that these images are extracted from scanned page images that
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
