System of stability and lability in hydra.

Hydra is a unique epigenetic system where simultaneous existence of stability and lability in its cells is encountered. The two terminal ends of the hypostome and basal disc have been designated as unipotentials, in between these two points the area is bipotential, i. e. it can form either basal disc or hypostome.The dynamic state of instability in hydra has been explained on the assumption that in case of a developmental urgency the mid equipotential system can transform into either or both kinds of unipotential through the action of some inhibitory complex.Hypostome as a developmental centre is more powerful than its counter centre namely the basal disc.