Studies on the origin and the pattern of the miniature electrical oscillation in the insect muscle.

In the cross-striated muscle of the vertebrate, the spontaneous activity is observed only in special experimental conditions, though it is usually observed in the iterative system such as the smooth muscle. On the other hand it was recently found by Fatt and Katz (3) that miniature spontaneous potentials were generated at the motor end plate. It has been noticed by Wakabayashi that the tymbal muscle of the cicada shows the miniature electrical oscillation which occurs while it is not active (Wakabayashi and Hagiwara (13)). Recently from the results of investigations of many species of insect muscles, Wakabayashi and Ikeda reported that the occurrence of the oscillation had systematic relation to the stage of phylogenetic development of the insect (14). Similar phenomena are found in the reports by Pringle (7) and Roeder (11) of the observation on the indirect flight muscle of the insect, but without special remarking. In this report the further investigation on the origin of this oscillation and the transition of the pattern of the oscillation is presented.