Coelomic pressure and electromyogram in earthworm locomotion

Abstract

1. 1. A method is described for recording electromyograms and coelomic pressure simultaneously from a segment of Lumbricus terrestris L. 2. 2. Contraction of the longitudinal muscles results in a “shortening peak” of coelomic pressure, and contraction of the circular muscles results in an “elongation peak”. 3. 3. Sequential muscular activation in successive segments is demonstrated, associated with a locomotory wave. 4. 4. Small, single potentials on the electromyogram may correspond with tonic muscular contractions.