“... Women are said to conceive more readily when down after the manner of beasts, as the organs can absorb the seed best so, when the bosom is depressed and the loins lifted” (Of the Nature of Things, IV., vv. 1259-1262).
Also Aloysia Sigaea:
“Some people pretend that the fashion to make love indicated by Nature is that one where the woman offers herself for copulation after the manner of the animals, bent down with the hips raised; the virile ploughshare penetrates thus more conveniently into the female furrow, and the seminal flow waters the field of love.... The doctors, however, are against this posture; they say it is incompatible with the conformation of the parts destined for generation.” (Dial. VI.)
However this may be, it happens frequently, that women cannot be managed in any other way. Given an obese man and a woman likewise obese or with child, how are they to do the thing otherwise? This is the reason why, so they say, Augustus having married Livia Drusilla, divorced wife of Tiberius Nero and already six months gone in pregnancy, had connection with her after the manner of animals. Plate VII of the Monuments de la vie privée des douze Césars will give you an idea of the posture assumed by both of them. But why should we not give you the annotations whereby the learned editor has elucidated the plate? Here they are:
“This Drusilla was the famous Livia, the wife of Tiberius Nero, who had been one of Anthony’s friends. Augustus fell violently in love with her, and Tiberius gave her up to him, although she was at the time six months with child. A good many jokes were made about the eagerness of the Emperor, and one day, while they were all at table, and Livia was reclining by Augustus, one of those naked children, whom matrons used to educate for their pleasures, going up to Livia said: “What are you doing here? yonder is your husband”, pointing to Nero, “there he is”[[18]]. Soon afterwards Livia was confined, and the Romans said openly, that lucky people get children three months after being married, which passed into a proverb. One historian says that Augustus was obliged to caress his wife “after the manner of beasts” on account of her pregnancy, and it was to this luxurious attitude that the cameo of Apollonius, the celebrated gem-cutter of the time of Augustus, makes allusion. True that the state in which Livia was may have made this posture necessary: but it seems that it was at all times to the taste of the Ancients, either because they considered this attitude favorable for procreation, as Lucretius maintains, or because they found it to be a refinement of voluptuousness. The most extraordinary and least natural postures have always appeared to rakes as enhancing the pleasure of the conjunction. But it must be admitted that imagination still outruns actual possibilities.”
A singular reason for the necessity of encountering a woman backwards is given by Aloysia Sigaea, with her usual sagacity:
“For pleasure, one likes a vulva which is not placed too far back, so as to be entirely hidden by the thighs; it should not be more than nine or ten inches from the navel. With the greater number of girls the pubis goes so far down, that it may easily be taken as the other way of pleasure. With such coition is difficult. Theodora Aspilqueta could not be deflowered, till she placed herself prone on her stomach, with her knees drawn up to her sides. Vainly had her husband tried to manage her, while lying on her back, he only lost his oil” (Dialogue VII).
Ovid recommends this way with women who begin to be wrinkled:
“Likewise you, whose stomach Lucina has marked with wrinkles, mount from behind, like the flying Parthian with his steed” (Art of Love, III., v. 785, 86).
The same advice also seems to be given by him a little before: