Chordates (phylum Chordata) are animals which are either vertebrates or one of several closely related invertebrates. They are united by having, for at least some period of their life cycle, a notochord, a HOLLOW DORSAL NERVE CORD
Usually under ground springs, or sometimes hollowed earth beneath solid earth where the water pools.
Phagocytes are the type of cells that 'devour' foreign cells in order to protect the body using phagocytosis.
