Nervous systems first developed in the chordates with the some of the simplest systems represented in [[flatworms]] which has two nerve cords running on opposite sides which connect with a simple [[brain]] called [[ganglia]]. | Nervous systems first developed in the chordates with the some of the simplest systems represented in [[flatworms]] which has two nerve cords running on opposite sides which connect with a simple [[brain]] called [[ganglia]]. |