but their culture and dress have affected the
whole region. [4] From this belt there have been extensive migrations
into Abra, the newcomers for the most part marrying with the Tinguian,
but in the Ikmin river valley emigrants from Balatok formed the towns
of Danok, Amti, and Doa-angan, which have remained quite isolated up
to the present time. Agsimao and other towns of the Tineg group, in
the extreme northern end of Abra, are made up chiefly of Apayao mixed
with Kalinga, while all the villages on the headwaters of the Binongan
have received emigrants from the Kagayan side. The population of the
towns properly classed as Tinguian is approximately twenty thousand
individuals. [5]

From the foregoing it is seen that, with the exception of a few
villages of mixed descent, all their territory lies on the western
side of the Cordillera Central, [6] the great mountain range which
runs from north to south through northern Luzon.

As one emerges from the jungle, which covers the eastern slopes of
these mountains, and looks down over the province of Abra, he sees
an exceedingly broken land (Plates I and II), the subordinate ranges
succeeding one another like the waves of the sea. The first impression
is one of barrenness. The forest vanishes, and in its place are long
grassy slopes, broken here and there by scattered pines and lower
down by dense growths of the graceful, feathery bamboo. But this lack
of trees is more fancied than real, for as one proceeds down any of
the valleys he meets with side canyons, where the tropical jungle
still holds sway, while many a mountain side is covered with a dense
undergrowth of shrubs, plants, and vines. It seems probable that the
forest once covered the western slopes of the mountains, but accident
and intention on the part of man has cleared broad sections. As soon
as the shade is removed, the land is invaded by a coarse grass (the
_cogon_), and this is burned over each year in order to provide feed
for the stock and to make good hunting grounds. The young trees are
killed off and reforesting prevented.

Numerous streams plunge from the high mountains toward the coast. In
places they rush through deep gorges between high mountains, again
they pass peacefully through mountain valleys. Everywhere they are
fed by minor streams and waterfalls until at last, as they emerge
into the broader valleys of the Abra and its tributaries, they are
rivers of respectable size.

The great central va