nly to mark the boundary
between land civilised and sacred and land uncivilised and profane.

As we have seen, the farms and homesteads of the early Latins were
grouped together in associations called _pagi_; and we can hardly doubt
that these were subjected to the same process of _lustratio_ as the
farms themselves. We have no explicit account of a circumambulation in
this case, but we have in the later poets several charming allusions to
a _lustratio pagi_, and it is of a rite of this kind that Virgil must
have been thinking when he wrote the beautiful passage in the first
Georgic beginning "In primis venerare deos";[449] and the lines

terque novas circum felix eat hostia fruges,
omnis quam chorus et socii comitentur ovantes, etc.,

clearly imply a procession with the object of keeping away harmful
influences from the crops at a critical time. And when the city-state
came into being we may be equally sure that its _ager_, so long at least
as it was small enough to admit of such a processional ritual, was
lustrated in the same way. In historical times this _ager_ had become
too extensive, and there is no procession to be found among the duties
of the Fratres Arvales as we know them when they were revived by
Augustus; but we have not, of course, the whole of the "acta" of the
Brethren, and even if we had, it would not be likely that we should find
any trace of a practice which must have been dropped in course of time
as the Roman territory increased. Let us go on to the beginnings of the
city, where we shall find the same principle and practice applied in
striking fashion.

As it was necessary to protect the homestead and its land by a sacred
boundary, so the city had to be clearly marked off from all that was
outside of it. Its walls were sacred, or, strictly speaking, a certain
imaginary line outside of them called the _pomoerium_ was sacred. This
is well shown in the traditional method of founding a city even in
historical times, _e.g._ a _colonia_, as described by Varro, Servius,
and Plutarch.[450] A white ox and a white cow were harnessed to a
plough, of which the share must be made of bronze--a rule which shows at
once the antiquity and the religious character of the rite, for iron, as
we saw, was taboo in most religious ceremonies. A rectangular furrow was
drawn where the walls of the city were to be; the earth was turned
inwards to mark the future line of the wall, and the furrow represented
the future