Cato, Varro and Columella all agree that slave labour was to be preferred to free except in unhealthy regions and for large occasional operations, which probably transcended the capacity of the permanent familia rustica.
At the head of the familia rustica was the villicus, himself a slave, with the wife who was given him at once to aid him and to bind him to his duties.
The slaves of a private Roman were divided between the familia rustica and the familia urbana.
To the familia urbana belonged those who discharged the duties of domestic attendance, the service of the toilet, bath, table and kitchen, besides the entertainment of the master and his guests by dancing, singing and other arts.
This is indeed an exaggeration; the colonatus was not an oppressive system; it afforded real security against unreasonable demands and wanton disturbance, and it was a great advance on the system of the familia rustica.