The evolutionary aspect has a wide field of application in medicine, especially where functions of the organism are concerned, and the evolutionary method has helped to gain a number of significant facts for physiology, as well as for pathology. This method may, especially if combined with other methods, contribute to a deeper understanding of the mechanism of some of the psychiatric syndromes, primarily those which have an analogue, or even a homologue, in phylogenesis or ontogenesis. As is well known, the basic types of reactions, which are common both to man and to animals, were designated by Kretschmer6as "biological radicals." The "motion storm" (Bewegungssturm) and the so-called animal hypnosis, also calledTotstellreflex, are such "biological radicals." Both are antipolar, phylogenetically old reactions with different forms of manifestation in animals and in man. The "motion storm" may be encountered in hysterical hyperkinesis: in sudden affective crises, as runs in