The vomeronasal organ or Jacobson's organ is an auxiliary olfactory sense organ in many vertebrates. It is located in the vomer, between the nose and the mouth. The sensory neurons within the vomeronasal organ detect distinct chemical compounds, usually chemical signals within the same species. Snakes use it to smell prey, sticking their tongue out and touching it to the organ. Some mammals make a face called flehmen[?] to direct air to this organ, which detects pheromones.
In humans it is subliminal, and there seems to be no direct neural connection between the organ and the brain.
... in 1486. The first English translation
(1502) was by William Atkinson and Margaret,
mother of Henry VII., who did the fourth book.
Translations appeared in ...