In some animals, such as some worms, there is a bisexuality of the individual.
"The Glands Regulating Personality"
Louis Berman, M.D.
bisexuality preceded monosexuality in the animal pedigree, and co-exists with it even at the highest points of the genealogical tree.
"The Glands Regulating Personality"
Louis Berman, M.D.
"Now their bisexuality permits them to reproduce themselves after the manner of true plants, but otherwise they have progressed but little in all the ages of their existence.
"The Gods of Mars"
Edgar Rice Burroughs