The pattern of electromagnetic field on the human scalp mapped by SQUID (Superconducting QUantum Interference Device) shows that the acupuncture point GV20 Baihui is a singular point at the surface magnetic field where the surface magnetic flux trajectories converge and enter the inside of the body. (Dr. Magnus Lou, personal communication) The Governor Vessel is a converging pathway of magnetic flux on the scalp and also a separatrix which divides the surface magnetic field into two symmetrical domains of different flow directions. A separatrix is a trajectory or boundary between spatial domains in which other trajectories have different behavior. Morphologically, the Governor Vessel is also the axis of symmetry on the scalp. This pattern is consistent with the pattern of the meridian system, but different from the distribution of any major nerve, lymphatic or blood vessel on the scalp. The morphogenetic singularity theory suggests that the meridian system is related to the bioelectric field in morphogenesis and growth control