Abstract
By stimulating the tibial nerve or peroneal nerve of Bufo vulgaris, action current was led from the dorsal root to investigate the wave form of the afferent impulse. The wave form always consisted of S1 wave and S2 wave. The velocity of S1 wave was 20.4m/sec and that of S2 wave was 15.6 m/sec. The myogenic efferent impulse was found. to consist solely of S1 wave, and the cutaneal afferent impulse was found to include S1 and S2 waves. Among these two, the one which demonstrates the reflex in Bufo vulgaris is S2 only.
In Bufo vulgaris, the reflexes are all the multi-neuron arc reflex. When the action current of the reflex volley was led from the ventral root, it was elucidated that this consisted of numerous groups of spikes. When the stimulus was weak, principally the reflex with long central delay, and, as the stimulus becomes stronger, reflex with short central delay tends to occur.
