descendants, the population of Borneo may be described as falling
naturally into two great classes; namely, on the one hand those
who have accepted, nominally at least, the Mohammedan religion and
civilisation, and on the other hand the pagan peoples. In Bruni and in
all the coast regions the majority of the people are Mohammedan, have
no tribal organisation, and call themselves Malays (Orang Malayu). This
name has usually been accorded them by European authors; but when
so used the name denotes a social, political, and religious status
rather than membership in an ethnic group. With the exception of these
partially civilised "Malays" of the coast regions and the imported
elements mentioned above, all the natives of Borneo live under tribal
organisation, their cultures ranging from the extreme simplicity of the
nomadic Punans to a moderately developed barbarism. All these pagan
tribes have often been classed together indiscriminately under the
name Dyaks or Dayaks, though many groups may be clearly distinguished
from one another by differences of culture, belief, and custom,
and peculiarities of their physical and mental constitutions.

The Mohammedan population, being of very heterogeneous ethnic
composition, and having adopted a culture of foreign origin, which
may be better studied in other regions of the earth where the Malay
type and culture is more truly indigenous, seems to us to be of
secondary interest to the anthropologist as compared with the less
cultured pagan tribes. We shall therefore confine our attention to
the less known pagan tribes of the interior; and when we speak of
the people of Borneo in general terms it is to the latter only that
we refer (except where the "Malays" are specifically mentioned). Of
these we distinguish six principal groups: (1) Sea Dayaks or Ibans,
(2) the Kayans, (3) Kenyahs, (4) Klemantans, (5) Muruts, (6) Punans.