Hence a gate was called porta, from porta're, to carry. The reason of this part of the ceremony was, that the plough being deemed holy, it was unlawful that any thing unclean should pollute the place which it had touched; but it was obviously necessary that things clean and unclean should pass through the gates of the city. It is remarkable that all the ceremonies here mentioned were imitated from the Tuscans.
This, though apparently a mere conjecture, has been so fully proved by Niebuhr, (vol. i. p. 251,) that it may safely be assumed as an historical fact.
See [Chapter II.] of the following history.
All authors are agreed that the Cœlian hill was named from Cœles Viben'na, a Tuscan chief; but there is a great variety in the date assigned to his settlement at Rome. Some make him cotemporary with Rom'ulus, others with the elder Tarquin, or Servius Tullius. In this uncertainty all that can be satisfactorily determined is, that at some early period a Tuscan colony settled in Rome.
Others say that they were named so in honour of Lu'ceres, king of Ardea, according to which theory the third would have been a Pelasgo-Tyrrhenian colony.