The question of the sexuality of prostitutes, which has a certain bearing on the question of their tendency to degeneration, has been settled by different writers in different senses. While some, like Morasso, assert that sexual impulse is a main cause inducing women to adopt a prostitute's career, others assert that prostitutes are usually almost devoid of sexual impulse. Lombroso refers to the prevalence of sexual frigidity among prostitutes.[177] In London, Merrick, speaking from a knowledge of over 16,000 prostitutes, states that he has met with "only a very few cases" in which gross sexual desire has been the motive to adopt a life of prostitution. In Paris, Raciborski had stated at a much earlier period that "among prostitutes one finds very few who are prompted to libertinage by sexual ardor."[178] Commenge, again, a careful student of the Parisian prostitute, cannot admit that sexual desire is to be classed among the serious causes of prostitution. "I have made inquiries of thousands of women on this point," he states, "and only a very small number have told me that they were driven to prostitution for the satisfaction of sexual needs. Although girls who give themselves to prostitution are often lacking in frankness, on this point, I believe, they have no wish to deceive. When they have sexual needs they do not conceal them, but, on the contrary, show a certain _amour-propre_ in acknowledging them, as a sufficient sort of justification for their life; so that if only a very small minority avow this motive the reason is that for the great majority it has no existence."