Another startling paragraph from the aforementioned 1908 book, which is a serious psychology text by the “Professor of Psychiatry at the Insane Asylum in Zurich”:
"Lesbian love merits special mention. Owing to the clitoris being more or less concealed, women are often not satisfied by coitus, especially when the ejaculation of the male takes place too quickly. Consequently a number of normal women prefer to procure an orgasm by means of lesbian love (cunnilingus.) There are clubs of female perverts, many of whom are not homosexual by heredity.”
— “The Sexual Question”, Marshall, 1908, p276
So in context he's saying that "straight" women, who aren't actually attracted to other women, have sex with women anyway because men are no good in bed.