Going northward into Bulacan we are in possession of more definite information regarding the whereabouts of these forest dwellers. Zuniga in 1803 spoke of the Negritos of Angat--in those days head-hunters who were accustomed to send messages by means of knotted grass stalks. [10] This region, the upper reaches of the Angat River, was visited by Mr. E. J. Simons on a collecting trip for The Ethnological Survey in February, 1903. Mr. Simons saw twenty-two little rancherias of the Dumagat, having a total population of 176 people. Some of them had striking Negroid characteristics, but nearly all bore evidence of a mixture of blood. In some cases full-blooded Filipinos have married into the tribe and adopted Negrito customs entirely. Their social state is about the same as that of the Negritos of Zambales, though some of their habits--for instance, betel chewing--approach more nearly those of lower-class Filipinos. A short vocabulary of their dialect is given in Appendix B. Negritos are also found in northern Bulacan and throughout the continuous mountain region extending through Nueva Ecija into Isabela and the old Province of Principe. They are reported from Penaranda, Bongabong, and Pantabangan, in Nueva Ecija, to the number of 500. This region is yet to be fully explored; the same may be said also of that vast range of mountains, the Sierra Madre, of Isabela and Cagayan. In the Province of Isabela Negritos are reported from all the towns, especially Palanan, on the coast, and Carig, Echague, Angadanan, Cauayan, and Cabagan Nuevo, on the upper reaches of the Rio Grande de Cagayan, but as there is a vast unknown country between, future exploration will have to determine the numerical importance of the Negritos. It has been thought heretofore that this region contained a large number of people of pure blood. This was the opinion set forth by Blumentritt. He says: This coast is the only spot in the Philippines in which the original masters of the Archipelago, the Negritos, hold unrestricted possession of their native land. The eastern side of the Cordillera which slopes toward this coast is also their undisputed possession. However, the western slopes they have been compelled to share with branches of Malay descendants. Here they retain the greatest purity of original physique and character. These statements stand much in need of verification. Inquiries pursued by The Ethnological Survey do not bear them out--in fact, point to an opposite belief. There is a small body of what may be pure types near the boundary between Isabela and Cagayan, west of the Cagayan River, but the coast region, so far as is known, does not hold any Negritos.