ound on dolmens and corridor-tombs in Palestine,
North Africa, Corsica, France, Germany, Scandinavia, and Great Britain.
In Wales there is a fine example of a dolmen with pits at Clynnog Fawr,
while in Cornwall we may instance the monument called "The Three
Brothers of Grugith" near Meneage.

There is no clue to the purpose of these pits. Some have thought that
they were made to hold the blood of sacrifice which was poured over the
slab, and from some such idea may have arisen some of the legends of
human victims which still cling round the dolmens. Others have opposed
to this the fact that the pits sometimes occur on vertical walls or
under the cover-slabs, and have preferred to see in them some totemistic
signification or some expression of star-worship. It is possible that we
have to deal with a complex and not a simple phenomenon, and that the
pits were not all made to serve a single purpose. Those which cover some
of the finest stones at Mnaidra and Hagiar Kim are certainly meant to be
ornamental, though there may be in them a reminiscence of some religious
tradition. In any case, it is worth while to remember that cup-markings
also occur on natural rocks and boulders in Switzerland, Scandinavia,
Great Britain (where there is a good example near Ilkley in Yorkshire),
near Como in Italy, and in Germany, Russia, and India.

Of the builders of the megalithic monuments themselves we cannot expect
to know very much, especially while their origin remains veiled in
obscurity. Yet there are a few facts which stand out clearly. We even
know something about their appearance, for the skulls found in the
megalithic tombs have in many cases been subjected to careful
examination and measurement. Into the detail of these measurements we
cannot enter here; suffice it to say that the most important of them are
the maximum length of the skull from front to back and its maximum
breadth, both measures, of course, being taken in a straight line with a
pair of callipers, and not round the contour of the skull. If we now
divide the maximum breadth by the maximum length and multiply the result
by 100 we get what is known as the cephalic index of the skull. Thus if
a skull has a length of 180 millimetres and a breadth of 135, its
cephalic index is 135/180 X 100, i.e. 75. It is clear that in a roundish
type of head the breadth will be greater in proportion to the length
than in a narrow elliptical type. Thus in a broad head the cephalic