e us here. Livy tells us that the method in
Macedonia was to march the whole host in spring between the severed
limbs of a dog:[455] the principle is here the same as in Italy, but the
method differs slightly. In each case some mysterious influence is
brought to bear on the whole army without exception; but in the one case
a line is drawn round it, in the other it passes through the parts of an
object which must have been supposed to be endowed with magical power.

And once more, in spring before the season of arms, all the belongings
of the host were subjected to some process of the same kind. I have
alluded to this in my lecture on the calendar, and need not now
reproduce the evidence of the Equirria at the end of February and on
March 14, or of the Quinquatrus on March 19, when the _lustratio_ took
place of the shields (_ancilia_) of the Salii, the war-priests of Mars,
and the Tubilustrium on March 23, which tells its own tale.[456] But I
may recall the fact that the calendar supplies us also with evidence
that on the return of the host to their own territory all these
lustrations had to be repeated in order to rid men, horses, arms, and
trumpets of such evil contagion as they might have contracted during
their absence. It may be that one special object of lustration after the
return of an army was to rid it, with all belonging to it, of the taint
of bloodshed, just as the Jewish warriors and their captives were
purified before re-entering the camp.[457] But in the Roman pontifical
law this idea is hardly discernible, and the only trace I can find of it
is a statement of Festus that the soldiers who followed the general's
car in a triumph wore laurel wreaths "ut quasi purgati a caede humana
intrarent urbem."[458] I may add here that the passage of a triumphing
army through the Porta triumphalis, which was probably an isolated arch
in the Campus Martius just outside the city wall,[459] most likely had
as its original meaning the separation of the host from the profane
world in which it had been moving; and the triumphal arches of later
times, which were within the city, were thus developed architecturally
from an origin which belongs to the region of magic.[460] To the same
class of ideas, if I am not much mistaken, belongs the familiar Italian
practice of compelling a surrendered army to pass under the yoke. As
Livy explains this when he first mentions it, it was symbolical of
subjection: "ut exprimatur confessio suba