Klino–kinesis of Paramecium

Abstract

IT has been shown by Ullyott¹ that the aggregation reaction of the flatworm, Dendroccelum lacteum, in a gradient of light intensities, can be described in terms of the rate of change of direction and the process of sensory adaptation in the eyes. This reaction has since been named ‘klino–kinesis’². More recently³, it was suggested that the well–known ‘phobo–taxis’ (‘avoiding reaction’, ‘trial–and–error’) of Paramecium might be sufficiently similar to be included under the same name. Preliminary experiments by one of us (B.M.W.), which cannot now be continued, provide support for this suggestion. Briefly, the experiments consisted in transferring Paramecium from the culture medium at pH. 8.0 to various strengths of acid or alkaline media, and finding the rate of change of direction as soon as possible and at intervals afterwards. It was found that it did depend on the change in pH. at first, and that it soon fell to the original basic level; these are the essential features of the klino–kinesis scheme.