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, but that they have been subjected to very different outside influences, probably prior to their entry into the Philippines. It is not in the province of this monograph to deal with the probable affiliations of the Igorot, neither is it our intention to attempt to locate the ancient home of the Tinguian, nor to connect them with any existing groups. However, our information seems to justify us in certain general conclusions. It shows that the oft repeated assertions of Chinese ancestry are without foundation. It shows that, while trade with China had introduced hundreds of pieces of pottery and some other objects into this region, yet Chinese influence had not been of an intimate enough nature to influence the language or customs, or to introduce any industry. On the other hand, we find abundant evidence that in nearly every phase of life the Tinguian were at one time strongly influenced by the peoples to the south, and even to-day show much in common with Java, Sumatra, the Malay Peninsula, and through them with India. As a case in point we find in the procedure at birth that the Tinguian are in accord with the Peninsular Malay in at least eight particulars, some of which, such as the burning of a fire beside the mother and newborn babe for a month or more, the frequent bathing of both in water containing leaves and herbs, the "fumigating" of the baby, the throwing of ashes to blind evil spirits, are sufficiently distinctive to indicate a common source, particularly when they still occur together in connection with one of the great events of life.