Nervous System

The earthworm has a brain and spinal cord through which basic nervous signals can be transmitted.
Each segment of the earthworm has a matrix of nerve cells that transport the nerve impulses toward the brain.

Prostomium
  • a tongue-like lobe above the mouth
  • used as a sensory device since earthworms do not have a nose, eyes, ears, or limbs
http://www.naturewatch.ca/english/wormwatch/resources/anatomy.html