f this ceremony: the first, that
no stranger should be present at it; and the second, that no citizen
should be absent from it. In the latter case the whole city might not
have been freed from impurity. The Suovetaurilia was therefore preceded
by a census, which was conducted with the greatest care both at Rome
and Athens. The citizen who was not enrolled and was not present at
the sacrifice could no longer be a member of the city. He could be
beaten and sold as a slave, this rule being relaxed only in the last
two centuries of the Republic. Only male citizens were present at
the sacrifice, but they gave a list of their families and belongings
to the censor, and these were considered to be purified through the
head of the family. [201]

This sacrifice was called a _lustratio_ or purification, and in the
historical period was considered to be expiatory. But it does not
seem probable that this was its original significance. For there would
not in that case have been the paramount necessity for every citizen
to be present. All females and children under power were purified
through the list given to the censor, and there seems no reason why
absent citizens could not have been purified in the same manner. But
participation in this sacrifice was itself the very test and essence
of citizenship. And it has been seen that a public meal was the
principal religious rite of the city. The conclusion therefore seems
reasonable that the Suovetaurilia was originally also a sacrificial
meal of which each citizen partook, and that the eating of the deified
domestic animals in common was the essence of the rite and the act
which conferred the privilege of citizenship. The driving of the
sacrificial animals round the citizens three times might well be a
substitute for the previous communal meal, if for any reason, such as
the large number of citizens, the practice of eating them had fallen
into abeyance. The original ground for the taking of a census was to
ensure that all the citizens were present at the communal sacrifice;
and it was by the place which a man occupied on this day that his rank
in the city was determined till the next sacrifice. If the censor
counted him among the senators, he remained a senator; if among the
equites, he remained a knight; if as a simple member of a tribe,
he belonged henceforward to the tribe in which he was counted. If the
censor refused to enumerate him, he was no longer a citizen. [202] Such
was the v