There are from 150,000 to 225,000 Igorot in Igorot land.  The census of the Archipelago taken in 1903 will give the number as about 185,000.  In the northern part of Pangasinan Province, the southwestern part of the territory, there are reported about 3,150 pagan people under various local names, as “Igorrotes,” “Infieles” [pagans], and “Nuevos Christianos.”  In Benguet Province there are some 23,000, commonly known as “Benguet Igorrotes.”  In Union Province there are about 4,400 primitive people, generally called “Igorrotes.”  Ilokos Sur has nearly 8,000, half of whom are known to history as “Tinguianes” and half as “Igorrotes.”  The Province of Ilokos Norte has nearly 9,000, which number is divided quite evenly between “Igorrotes,” “Tinguianes,” and “Infieles.”  Abra Province has in round numbers 13,500 pagan Malayans, most of whom are historically known as “Alzados” and “Tinguianes.”  These Tinguian ethnically belong to the great Igorot group, and in northern Bontoc Province, where they are known as Itneg, flow into and are not distinguishable from the Igorot; but no effort is made in this monograph to cut the Tinguian asunder from the position they have gained in historic and ethnologic writings as a separate people.  The Province of Lepanto-Bontoc has, according to records, about 70,500 “Igorrotes,” “Tinguianes,” and “Caylingas,” but I believe a more careful census will show it has nearer 100,000.  Nueva Ecija is reported to have half a hundred “Tinguianes.”  The Province of Nueva Vizcaya has some 46,000 people locally and historically known as “Bunnayans,” a large group in the Spanish comandancia of Quiangan; the “Silapanes,” also a large group of people closely associated with the Bunayan; the Isinay, a small group in the southern part of the province; the Alamit, a considerable group of Silipan people dwelling along the Alamit River in the comandancia of Quiangan; and the small Ayangan group of the Bunayan people of Quiangan.  Cagayan Province has about 11,000 “Caylingas” and “Ipuyaos.”  Isabela Province is reported as having about 2,700 primitive Malayans of the Igorot group; they are historically known as “Igorrotes,” “Gaddanes,” “Calingas,” and “Ifugaos.”

The following forms of the above names of different dialect groups of Ig-o-rot’ have been adopted by The Ethnological Survey:  Tin-gui-an’, Ka-lin’-ga, Bun-a-yan’, I-sa-nay’, A-la’-mit, Sil-i-pan’, Ay-an’-gan, I-pu-kao’, and Gad-an’.

It is believed that all the mountain people of the northern half of Luzon, except the Negritos, came to the island in some of the earliest of the movements that swept the coasts of the Archipelago from the south and spread over the inland areas —­ succeeding waves of people, having more culture, driving their cruder blood fellows farther inland.  Though originally of one blood, and though they are all to-day in a similar broad culture-grade —­ that is, all are mountain agriculturists, and all are, or until recently have been, head-hunters —­