The meaning of the term "klinokinesis"

The original definition of the term klinokinesis was based on an account by Ullyott (1936) of the behaviour of the flatworm, Dendrocoelum lacteum, an account recently shown to be unsound. Recently, the behaviour of Escherichia coli and of Salmonella typhimutium in chemical gradients has been found to conform to the definition, so the term can continue in use. But no uncomplicated case has been found in metazoans, though the manoeuvres of klinokinesis may make large contributions to the behaviour of some of them, even though it may be complicated and obscured by other types of reaction, such as orthokinesis. What is needed is mathematical treatment sufficiently thorough to enable the existence of the reaction in metazoans to be ascertained. There may well be other systems of manoeurvres using random changes of direction and these should be sought and investigated.