THE EFFECT OF CYANIDES ON THE SWELLING OF PROTOPLASM

Abstract

Arbacia eggs were exposed to solutions of HCN and KCN in concentrations of N/300-N/2000 for definite periods, transferred to 50% sea-water, and the change in volumes of the eggs was measured at 1 min. intervals. HCN in these concentrations increases the permeability of the eggs to water when placed in hypotonic sea-water, the rate of increase varying directly with the concentration of HCN and the length of exposure. KCN decreases the permeability to sea-water under the same conditions, the rate of decrease varying directly with its concentration. Both HCN and KCN act as anaesthetics, the HCN being more powerful. Anaesthetized eggs can be fertilized while in that condition, but cell cleavage is delayed until the anaesthetic has diffused out or until the narcotic condition has been reversed. It is suggested that it is the HCN molecules present in a solution of KCN which cause anaesthesia by this salt.