Whilst the greatest effort has been made to ensure the quality of this text, due to the historical nature of this content, in some rare cases there may be minor issues with legibility. They are merely intended to bring certain subjects up to date and to create familiarity with others. To bring up to date the whole question of moral offenses, some parts of which have taken on a singularly different aspect since Tardieu's classical and original work, and to create familiarity with the whole question of the perversions of the sexual instinct, a question almost denied yesterday, and still unknown to the majority Of physicians and students despite its triple interest, clinical, psychological and medicolegal.