Investigations on the effect of a direct electric current on the ciliary motion of the Anodonta gill1

Kistiakowsky was the first to show that electrical stimulation a.ffected the ciliary motion.The influence of this stimulation has hitherto been studied chiefly on the pharyngeal epithelium of the frog (Kistiakowsky, E n g e l m a n n , on the cilia of infusoria and the flagella of flagellates (Verworn, Loeb and B u d g e t t , Jennings, P e a r l , Wallengren etc.) and on the ciliary rows in ctenophores (Gothlin).Stimulation of infusorians and flagellates soon led to the discovery of the extremely interesting and subsequently eagerly studied galvanotactic phenomena.Although in a great number of cases the galvanotactic effects of the current on the movements of infusorians and flagellates have proved to be of a regular nature, yet up to now it has not been possible to get from these rather complicated phenomena any simple laws as to the modifying effect of the electric current on the natural manifestations of movement in the separate cilia.Verworn, who has made the greatest contribution to the theory of galvanotaxis has, apparently from a feeling of these difficulties, expressed himself as follows (Verworn, 1915, p. 560) : ,,Welcher spezielle Faktor in dem Komplex von Bedingungen, den wir als galvanischen Strom bezeichnen, die charakteristischen Erregungen und Hemmungen der Wimpertatigkeit hervomft, deren ' Ausdruck die galvanotaktische Achseneinstellung und Schwimmbewegung der Infusorienzelle ist, diese Frage miissen a i r . . .vorlaufig offen lassen."