Having no cattle of his own in the herd, the herdsman’s testimony as to whose cattle were injured, and as to whose cattle had done the injury, was held, when such cases arose, to be sufficient to make the owner responsible, while as regards injuries done by the cattle of one trefgordd to those of another there was joint responsibility.[42] There is common sense in such rules to begin with, and then, having grown into custom, they become perpetuated when custom is codified.
The trefgordd possessed further a common churn. This implies that the milk of the cows was thrown altogether into this one churn as in Swiss mountain communes now. One of the dues from a taeog trev, _i.e._ a group of _non_-tribesmen, was a cheese made from a day’s milking of all the cows in the herd. So that we note in passing that the taeog-tref, _i.e._ of non-tribesmen, also had its herd and was in fact a trefgordd.[43]
In winter the cattle came down into the lowlands and grazed on the pastures near the tyddyns or homesteads of the tref, and as each of these had its corn and cattle-yard,[44] we may conclude that each owner penned in his own cattle at night during the winter months or joined with some other tribesmen who had a homestead in doing so. The rules as to the divisions of the tyddyns probably referred to these winter homesteads so held in quasi-severalty.
We need not dwell upon the common _oven_. Every hamlet in Brittany possesses its common oven to this day, often in the middle of the village green. Nor need we more than mention the common plough, to the team of which the tribesmen contributed oxen for the _cyvar_ or common ploughing of the portion of the waste agreed upon for each year’s corn crop.
[Sidenote: The trefgordd the unit for food rents. The tribesmen could be shifted about.]
The attempt to realise what this practical unit--the trefgordd--was, will not be thrown away if it should help us to understand how easily it lent itself to the arrangement of the chieftain’s food-rents or tribute in after-times of taxation. Granted that some such system of trefgordds or clusters of trefgordds pretty generally prevailed, having grown up as a matter of convenience in a grazing community, it is obvious how easily it might become the unit of tribute or taxation. Just as in the Domesday Survey the number of ploughs affords such a unit, so in a tribal community a district might easily be fiscally estimated at so many herds, or so many churns, or so many ploughs. All these would mean so many trefgordds. And whatever the relations of the trefgordd to the villata of the surveys might be, and however much or often the actual residents, with their herds, might be shifted from one district to another, the district, as in the Denbigh Extent, would remain the permanent unit for payments.