certainly, though it cannot be enforced by mere
authority, it is recommended by its simplicity,--avoiding, as it does,
the unnecessary multiplication of causes. The goat was certainly
indigenous, but no more certainly domesticated than the equally
indigenous deer. This indigenous rein-deer may or may not have been
trained. The miserable aliments of the beach, shell-fish and crustacea,
constituted no small part of the earliest human food; and so (for the
northern part of the isle at least) did eggs, seals, and whales. Surely
in these primitive portions of the Stone period our habits must have
approached those of the Lap, the Samoeeid, and the Eskimo, however
different they may be now.

But metals, in the course of time, were introduced; first bronze, and
then iron; gold and lead being, perhaps, earlier than either, earlier
too than silver. Of gold we take but little notice. It was not a useful
metal; but subservient only to the purposes of barbaric ornament. The
next fact is of great importance.

_In those tombs where the implements are most exclusively of stone, and
where the other signs of antiquity correspond, the skulls are of
unusually small capacity. In the next period they are larger. There are
also some notable points of difference in the shape._ Such at least is
the current opinion; although the proofs that such difference is not
referable to difference of age or sex, is by no means irrefragable.
Still we may take the fact as it is supposed and reported to be.

If we do this, we are prepared for another question. How far is the
introduction of metal implements and of new arts, a sign of the
introduction of a fresh stock or variety of the human species? How far,
too, is the difference in the capacity of the skulls? How far the fact
of the two changes coinciding? The answer has generally been in the
affirmative. The men who used implements of bronze were Kelts; the men
who eked out their existence with nothing better than adzes and
arrow-heads of stone, were other than Keltic. They were ante-Keltic
aborigines, whom a Keltic migration annihilated and superseded. Such is
the widely-spread doctrine. Yet it is doubtful whether the premises bear
out the inference--far as it has been recognized. I doubt it myself;
because, admitting (for the sake of argument) that there is a difference
in the size and the shape of the skulls, it by no means follows that a
difference of stock is the only way of accounting for it. Impro