Abstract
1. Employing toad's single myelinated nerve fibres as material, the electrical activity as modified by aniso-osmotic (particularly hypertonic) solutions was investigated.
2. Decrease in magnitude of action current, rise of threshold and remarkable prolongation of action duration were observed.
3. The maximal local response in hypertonic solutions is much larger than that in normal Ringer.
4. Anode break excitation is easily elicitable in hypertonic media.
5. Some microscopic signs, probably indicating hydration or dehydration, were obtained.
