is convinced that the Apayao and Tinguian are divisions of the same
people, who have been separated only a comparatively short time.

In the introduction to the present volume (p. 236) I have expressed
the opinion that the Tinguian and Ilocano are identical, and that
they form one of the waves of a series which brought the Apayao and
western Kalinga to northern Luzon, a wave which reached the Islands
at a later period than that represented by the Igorot, and which
originated in a somewhat different region of southeastern Asia. [26]

In order to come to a definite decision concerning these various
theories, we shall inquire into the cultural, linguistic, and physical
types of the people concerned.

The most striking cultural differences between the Igorot and the
Tinguian, indicated in the introduction, will be brought out in more
detail in the following pages, as will also the evidence of Chinese
influence in this region. Here it needs only to be restated, that
there are radical differences in social organization, government,
house-building, and the like, between the Igorot-Ifugao groups,
and the Ilocano-Tinguian-Apayao-Kalinga divisions.

All the tribes of northwestern Luzon belong to the same linguistic
stock which, in turn, is closely related to the other Philippine
languages. There are local differences sufficiently great to make it
impossible for people to communicate when first brought together,
but the vocabularies are sufficiently alike, and the morphology of
the dialects is so similar that it is the task of only a short time
for a person conversant with one idiom to acquire a speaking and
understanding knowledge of any other in this region. It is important