Cæsar is the earliest known writer to give the name Brittania to the island of Britain and the name Brittani to its people. In earlier writings the name of the island is Albion. In Cæsar's term Brittani, there seems to be a confusion of two existing names, one Brittani, the name of a small local population, the other Pretani which is recognised to be a British and probably Gaulish equivalent of the Irish name for the Picts, Cruithin, more anciently Qreteni. Cæsar fixed the name Brittani in Latin usage, but the form Pretanoi continued after his time to be used by Greek writers. Polybius and Ptolemy apply the adjective Pretanic to the two islands, and a still later geographical tract in Greek says, "the Pretanic islands are two in number one called Albion and the other Ierne." The Pretanic islands means the Pictish islands, and this name for them must have been taken from the Gauls. It points to a time before the Celtic occupation, when the Pretani or Picts were still regarded as the principal people of both islands. Here we have another indication of the relatively late period of the Celtic occupation. Cæsar learned that the natives of Britain had some curious marital customs which he did not observe among the Gauls, including the Belgae, on the Continent. A later writer, Solinus, in whose time the customs of the Britons were more intimately known to the Romans, ascribes a similar custom, not to the Britons but to the inhabitants of the Hebrides. Both accounts are based on a well-established fact, recorded also in Irish writings, the custom of matriarchy which was peculiar to the Picts. Cæsar's statement is readily explained, if we understand that the Gauls, from whom his information was likely to have been derived, still spoke of Britain and Ireland as the Pictish islands, and regarded this social custom, which was foreign to them, as a Pictish custom. In the time of Solinus, the Romans knew that the Picts were limited to the northern parts of Britain, and the story is accordingly told of the people of the Hebrides. If a custom peculiar to the Picts was spoken of in Cæsar's time as common to the inhabitants of Britain, and if Britain and Ireland were then still regarded in Gaul as Pictish islands, I suggest that this was because the Celts of Gaul did not look upon the two islands as having been mainly occupied from any remote period by a people akin to themselves.