Note 239 — Chapter II · THE CONCEPTION AND THE GENETIC THEORY OF LIBIDO
Beatrice M. Hinkle translation
Freud: Ibid., p. 14. “One definite kind of contiguity, consisting of mutual approximation of the mucous membranes of the lips in the form of a kiss, has among the most civilized nations received a sexual value, though the parts of the body concerned do not belong to the sexual apparatus but form the entrance to the digestive tract.”