Composition of the Cell Sap of Halicystis Ovalis (Lyng.) Areschoug. ∗

Abstract

The cell sap of a species of Halicystis which “is cast up on the beaches as clear green, balloon shaped cells” at Bermuda was analyzed by Osterhout and Dorcas 1 and reported to differ strikingly from that of Valonia macrophysa Kütz, collected at Bermuda, as determined by Wodehouse 2 and by Osterhout. 3 The contrast seemed all the more striking since the species was at that time erroneously identified as Valonia ventricosa J. G. Ag. This identification was subsequently revised by Blinks, 4 who considers the species analyzed by Osterhout and Dorcas to be Halicystis ovalis (Lyng.) Areschoug.

Osterhout and Dorcas 1 reported that while cells of Valonia macrophysa contain a sap which is very rich in potassium and poor in sodium, precisely the opposite condition obtains in Halicystis (which they call Valonia ventricosa). The ratios of potassium to sodium in the two forms were found to be 5.72 and 0.0278 respectively. Since the cells which they analysed floated in sea water while normal Valonia cells of either species sink, 5 it appeared questionable whether these cells were entirely normal. Osterhout and Dorcas 1 say in this connection: “The writers made every effort to obtain young growing cells…. During the past 2 years a few cells apparently of the same species have been found attached…. Unfortunately there seems to be no prospect of obtaining such cells in sufficient quantity for analysis.” The analysis reported by them refers to cells torn loose from their habitat and drifted ashore.

Blinks 6 has recently reported that the electromotive forces developed by cells of Halicystis differ strikingly from those previously observed with Valonia. He states: “The sap of the small cells used in these experiments was essentially the same in composition as that of the large floating cells” as previously reported by Osterhout and Dorcas.