The Nerves and Muscles of Medusae

摘要: 1. The responses of Geryonia proboscidalis to electrical and mechanical stimulation have been studied with particular attention the transmission excitation. 2. There are two kinds excitation transmitted across undersurface bell; first, symmetrical beat is co-ordinated by an isotropic conducting system which acts in a through-conducting, all-or-nothing manner, produces brief contractions circular muscle; secondly, movements manubrium radial system, maintained contraction muscles manubrium. 3. independence these systems shown simultaneous yet distinct different directions. 4. wave not through ring nerves faster than over rest bell. 5. bends towards stimulated tentacle, all tentacles contract simultaneously, through-conducting pathway marginal nerve. evidence that polarized carries from this rhythmical centres. 6. Observations held axis horizontal show steering action due asymmetrical velum. 7. known histological details nervous compared physiological pathways demonstrated experiment. differentiation primitive nerve net into tracts separate functions essential for several rapid feeding swimming activities.