1. Laminaria exposed for a short period to 0.52 M NaCl loses a part of its electrical resistance but recovers it completely when replaced in sea water. When the period is lengthened recovery is incomplete. If the exposure is sufficiently prolonged no recovery occurs. (After exposure to 0.278 M CaCl2 the resistance falls when the tissue is replaced in sea water.)
2. Equations are developed which enable us to predict the resistance of the tissue during exposure to NaCl or CaCl2 as well as the recovery curves after any length of exposure to either of these solutions.