De Agricultura
Philo Judaeus
The works of Philo Judaeus, the contemporary of Josephus, volume 1. Yonge, C. D., translator. London: Henry G. Bohn, 1854.
On which account nature, as it would seem, has placed the organs of such connection beneath the belly, being previously aware that they do not delight in hunger, but that they follow upon satiety and then rise up to fulfil their peculiar operations.