Physiological Effects of a Hypotonic Environment

Abstract

ABSTRACT If polychaete rhythmic muscles are suspended in sea water, which is then suddenly replaced by dilute sea water, they typically respond to the change by showing, first excitation, then inhibition, then accommodation to the new fluid (Wells & Ledingham, 1940a). Shock effects, followed by accommodation, have also been shown to follow sudden salinity change in marine amoebae (Pantin, 1924) and in the hearts of Limulus, Carcinus and a tortoise (Carlson, 1905; Girault, 1935). The experiments here described were undertaken primarily in order to find out whether similar phenomena occur in cilia. The action of hypotonic fluids on the lamellibranch gill has been described by Fredericq (1922) and by Tomita (1934), but neither author paid any attention to the behaviour of the cilia immediately after salinity change.