It is therefore a fair inference that, with the Saxon colonisation, the Saxon denominations superseded the older Celtic lesser denominations, as forming the subdivisions of the Davach in the eastern districts, while in the western seaboard and in the islands, which were for a time under Norwegian rule, the Norwegian denominations replaced the Celtic, but in both cases they were adapted to the existing divisions of land, which could not be altered without interfering with the whole framework of society. The Carucate or ploughgate was a term known to the Irish system, and may likewise have existed in Scotland in Celtic times, as it appears in Highland charters under the name of _Arachor_, the Gaelic equivalent of the Latin _Aratrum_,[268] but seems sometimes to have contained 160 acres in place of 104, and consisted of a definite measure of arable land with common pasture;[269] and we find from a charter of a Carucate or ploughgate of land on the Nith, that the common pasture carried 24 cattle and 100 sheep,[270] and the minor terms can probably still be traced in the topography of the districts. We have the words _Ballin_, _Bal_, from _Baile_, a town, entering into many local names in both parts of the country, as well as the word _Teaghlach_ or family, corrupted into Tully and Tilly, as in Tullynessle, Tillymorgan, etc. Then in the east there are the Pits, the old form of which, as appears from the Book of Deer, was _Pette_ or _Pett_. It is there uniformly connected with a personal name, as if it was applied to a single homestead, as in _Pette mac Garnait_, _Pett mac Gobrig_, and _Pett Malduib_, and the affix Pitt seems to have a similar meaning in the old entry in the Chartulary of St. Andrews, where we read of the ‘villula’ or homestead, which is called Pitmokane.[271] In the western districts we find the penny land also entering into the topography, in the form of _Pen_ or Penny, in such names as Pennyghael, Pennycross, Penmollach, while the halfpenny becomes _Leffen_, as in Leffenstrath; and if the group of twenty houses, which we found characterising the early tribe organisation in Dalriada, was the Davach, then we obtain the important identification of these houses or homesteads with the later penny lands. We find notices in the charters connected with this part of the country of the _Shammark_, equal to two penny lands, of Cow lands, probably the Irish _Ballyboe_, and of Horsegangs.[272] When these western districts fell under the rule of the Scottish monarchs, the valuation of land called the Old Extent seems to have been to some extent introduced. In the eastern districts it corresponded so far with the land measures, that the ploughgate was the same as the forty shilling or a three-merk land;[273] but the merk land in the west appears to have had no uniform relation to the penny land, though in Lochaber we find that five penny lands were equal to a forty-shilling land, which seemed to indicate that