Migne, Patrologia Græca, vol. xxvi, pp. 1170 et seq.
Even in physical conformation the human sexual organs, when compared with those of the lower animals, show marked differences (see "The Mechanism of Detumescence," in the fifth volume of these Studies).
It may perhaps be as well to point out, with Forel (Die Sexuelle Frage, p. 208), that the word "bestial" is generally used quite incorrectly in this connection. Indeed, not only for the higher, but also for the lower manifestation of the sexual impulse, it would usually be more correct to use instead the qualification "human."