Nervous System
Represented by ganglia, which are arranged segmentwise on the ventral-paired nerve cord
The nerve cord in the anterior region (3rd and 4th segments) bifurcates and joins the cerebral ganglia to form a nerve ring.
Cerebral ganglia and other nerves:
Integrate sensory input
Command muscular responses of the body
Earthworms lack eyes, but do posses light and touch-sensitive organs.
Have specialised chemoreceptors (taste receptors) which react to chemical stimuli
Sense organs are located on the anterior part of the body.