study of the physical types has shown that each group considered
is made up of heterogeneous elements. Pigmy blood is everywhere
evident, but aside from this there is a well-marked brachycephalic
and a dolichocephalic element. With the latter is a greater tendency
than with the first for the face to be angular; the cheek bones
are more outstanding, while there is a greater length and breadth
of the nose. Individuals of each type are found in all the groups
considered, but taken in the average, it is found that the Ilocano
and Valley Tinguian fall into the first or round-headed class, the
Bontoc Igorot are mesaticephalic, while between them are the mountain
Tinguian and Apayao.

Judging from their habitat and the physical data, it appears that
the Igorot groups were the first comers; that the brachycephalic
Ilocano-Tinguian arrived later and took possession of the coast,
and that the two groups have intermarried to form the intermediate
peoples. However, a comparison of our Luzon measurements with the
people of southern China and the Perak Malay leads us to believe
that the tribes of northwestern Luzon are all closely related to
the dominant peoples of southern China, Indo-China, and Malaysia in
general, in all of which the intermingling of these types is apparent.

The dialects of northwestern Luzon, while not mutually intelligible,
are similar in morphology, and have a considerable part of their
vocabularies in common. Here again the Igorot is at one extreme, the
Ilocano and Valley Tinguian at the other, while the intervening groups
are intermediate, but with a strong leaning toward the coast tongue.

Considering, for the moment, the Bontoc Igorot and the Tinguian, it is
found that both have certain elements of culture which are doubtless
old possessions, as, for instance, head-hunting, terraced rice-fields,
iron-working, a peculiar type of shield, and a battle-axe which they
share with the Apayao of Luzon and the Naga of Assam.

A part or all of these may be due to a common heritage, at any rate,
they help to strengthen the feeling that in remote times these
peoples were closely related. But a detailed study of their social
organizations; of their ceremonies, songs, and dances; of their customs
at birth, marriage, death, and burial; of their house-building; as
well as the details of certain occupations, such as the rice culture,
pottery making, and weaving, indicates that not only have they been
long separated, bu