BISEXUALITY • E-FREE TRANSLATION.COM • Definition of Bisexuality

... persisting in various degrees in many species—snails, earth-worms, and leeches, for example, can act alternately as what we call male and female. Other animals are hermaphrodite in their young stages, though the sexes are separate in adult life, as, for example, tadpoles, where the bisexuality of youth sometimes linger into adult life. Cases of partial hermaphroditism are very common, while in many species which are normally unisexual, a casual or abnormal hermaphroditism occurs—this may be seen in the common frog, and is frequent among ...

— The Truth About Woman • C. Gasquoine Hartley

... toward masculinity or femininity." But "at the same time," he remarks, "it is equally obvious that latent traits of the opposite sex are always present." After discussing mental traits observed in each sex which normally belong to the other, he concludes as follows: "If further evidence of this bisexuality, which exists in everyone, were required, it is to be found in the embryological remains of the latent sex, which always exist ...

— Taboo and Genetics • Melvin Moses Knight, Iva Lowther Peters, and Phyllis Mary Blanchard