By means of vibrations or shocks transmitted through the - Sub water, or by displacements in the balance or position of the animal, the otoliths are caused to impinge against the bristles of the sensory cells, now on one side, now on the other, causing shocks or stimuli which are transmitted by the basal nerve-fibre to the central nervous system.
It bears a group of long setose hairs the bases of which are connected with the nerve fibre.
The chemical changes that accompany activity in the nerve fibre must be very small, for the production of CO 2 is barely measurable, and no production of heat is observable as the result of the most forced tetanic activity.
