advises that
slaves should not be bred, but should be purchased not under 22 years
of age; and Cato must have had a similar course in view, as the
personal staff of his model farm clearly shows, although he does not
exactly say so. Cato (2) expressly counsels the sale of old and
diseased slaves. The slave-breeding described by Columella (I. I.
Italian History), under which female slaves who had three sons were
exempted from labour, and the mothers of four sons were even
manumitted, was doubtless an independent speculation rather than a
part of the regular management of the estate--similar to the trade
pursued by Cato himself of purchasing slaves to be trained and sold
again (Plutarch, Cat. Mai. 21). The characteristic taxation mentioned
in this same passage probably has reference to the body of servants
properly so called (-familia urbana-).

7. In this restricted sense the chaining of slaves, and even of the
sons of the family (Dionys. ii. 26), was very old; and accordingly
chained field-labourers are mentioned by Cato as exceptions, to whom,
as they could not themselves grind, bread had to be supplied instead
of grain (56). Even in the times of the empire the chaining of slaves
uniformly presents itself as a punishment inflicted definitively by
the master, provisionally by the steward (Colum. i. 8; Gai. i. 13;
Ulp. i. ii). If, notwithstanding, the tillage of the fields by means
of chained slaves appeared in subsequent times as a distinct system,
and the labourers' prison (-ergastulum-)--an underground cellar with
window-aperatures numerous but narrow and not to be reached from the
ground by the hand (Colum. i. 6)--became a necessary part of the farm-
buildings, this state of matters was occasioned by the fact that the
position of the rural serfs was harder than that of other slaves and
therefore those slaves were chiefly taken for it, who had, or seemed
to have, committed some offence. That cruel masters, moreover,
applied the chains without any occasion to do so, we do not mean to
deny, and it is clearly indicated by the circumstance that the law-
books do not decree the penalties applicable to slave transgressors
against those in chains, but prescribe the punishment of the half-
chained. It was precisely the same with branding; it was meant to be,
strictly, a punishment; but the whole flock was probably marked
(Diodor. xxxv. 5; Bernays, --Phokytides--, p. xxxi.).

8. Cato does not expressly say this as to