This also is an ancient remark, for in the early treatise De Secretis Mulierum, once attributed to Michael Scot, it is stated, concerning the woman who finds pleasure in coitus, "cantat libenter."
It is scarcely necessary to add that prostitutes can furnish little evidence one way or the other. Not only may prostitutes refuse to participate in the sexual orgasm, but the evils of a prostitute's life are obviously connected with causes quite other than mere excess of sexual gratification.
This is, for instance, indicated by the experiments of Gualino concerning the sexual sensitiveness of the lips (Archivio di Psichiatria, 1904, fasc. 3). He found that mechanical irritation applied to the lips produced more or less sexual feeling in 12 out of 20 women, but in only 10 out of 25 men, i.e., in three-fifths of the women and two-fifths of the men.