If both Kenyahs and Klemantans represent sections of the aboriginal population of nomadic hunters who have absorbed Kayan culture, it remains to account for the existence of those peculiarities of the Kenyahs that have led us to separate them from the tribes which we have classed together as Klemantans. The peculiarities that distinguish Kenyahs from Klemantans are chiefly personal characteristics, notably the bodily build (relatively short limbs and massive trunks), the more lively and energetic temperament, the more generous and expansive and pugnacious disposition. These peculiarities may, we think, be accounted for by the supposition that the aborigines from whom the Kenyahs descend had long occupied the central highlands where most of the Kenyah communities still dwell and which they all regard as the homeland and headquarters of their race.
Of the Klemantan tribes some, E.G. the Aki, the Long Patas, and the Long Akars, resemble more nearly the Kayans; others, E.G. the Muriks, the Sebops, the Lirongs, the Uma Longs, the Pengs or Pinihings, show more affinity with the Kenyahs. It seems probable that these diversities have resulted from the assimilation of culture directly from the Kayans by the one group and from the Kenyahs by the other. A third group of Klemantan tribes such as the Long Kiputs, the Batu Blah, and the Trings, scattered through the northern part of the island, resemble more nearly the Muruts; and among these are found communities whose culture marks them as descendants of nomads who have assimilated the Murut culture in various degrees.
The Muruts
The Muruts differ somewhat as regards physical features from all the other tribes, especially in having coarser but less Mongoloid features, a longer skull, and a more lanky build of body and limbs. Their intonation is nasal, and the colour of the skin slightly darker and ruddier than that of the Klemantans.
Their culture differs so much as to lead us to suppose that it had a somewhat different origin from that of the Kayans. They build long houses; but these are comparatively flimsy structures, and they are often situated at a distance from any navigable stream. Even those Muruts who live on the river-banks make much less use of boats than the other tribes, and all of them are great walkers. They have very little skill in boat-making. Their most distinctive peculiarity is their system of agriculture (see vol. i. p. 97), which involves irrigation, the use of buffalo, the raising of two crops a year, and the repeated use in successive years of the same land. Other distinctive features are their peculiar long sword and short spear; the absence of any axe and blow-pipe; the custom according to which the women propose marriage to the men (Kalabits).
In the Philippine Islands a system of agriculture similar to that of the Muruts is widely practised; and some of the tribes, though their culture has been largely influenced by Spanish civilisation, seem to be of the same stock as the Muruts; thus the Tagals of Borneo are not improbably a section of the people known as Tagalas in the Philippines, and the Bisayas of Borneo probably bear the same relation to the Visayas of the Philippines.
It seems probable, therefore, that this type of culture has been carried into the north of Borneo by immigrants from the Philippines, whither it was introduced at a remote period, possibly from Annam, the nearest part of the mainland; or possibly it came to Borneo directly from Annam.[205] It is probable that many of the tribes which we have classed with the Muruts, on account of their possession of the Murut culture, are, like the Klemantans and Kenyahs, descendants of the ancient Indonesian population who have adopted the culture of more advanced immigrants. The descendants of the immigrants who introduced this type of culture are, we think, the Muruts proper, who claim that name and dwell chiefly in the Trusan, the Padas, the Sembakong, the Kerayan rivers, and in the head of the Kinabatangan; also the Kalabits in the northern part of the upper basin of the Baram. It is these which display most decidedly the physical peculiarities noted above.
As examples of Klemantan tribes that have partially adopted the Murut culture we would mention the LONG KIPUTS, the BATU BLAHS, the TRINGS, and the ADANGS in the head of the Limbang River; to the same group belong the KADAYANS in the neighbourhood of Bruni, who, from contact with their Malay neighbours, have become in large part Mohammedans of Malay culture.
The Ibans (Sea Dayaks)
The Ibans stand distinctly apart from all the other tribes, both by reason of their physical and mental peculiarities and of the many differences of their culture; we have little doubt that they are the descendants of immigrants who came into the south-western corner of Borneo at no distant date. We regard them as Proto-Malays, that is to say, as of the stock from which the true Malays of Sumatra and the Peninsula were differentiated by the influence of Arab culture. A large number of the ancestors of the present Ibans were probably brought to Borneo from Sumatra less than two hundred years ago. Some two centuries ago, a number of Malay nobles were authorised by the Sultan of Bruni to govern the five rivers of Sarawak proper, namely, the Samarahan, the Sadong, the Batang Lupar, the Saribas, and the Klaka rivers. These Malays were pirate leaders, and they were glad to enrol large numbers of pagan fighting men among their followers; for the latter were glad to do most of the hard work, claiming the heads of the pirates' victims as their principal remuneration, while the Malays retained that part of the booty which had a marketable value. These Malay leaders found, no doubt, that their pagan relatives of Sumatra lent themselves more readily to this service than the less warlike Klemantans of Borneo, and therefore, as we suppose, they brought over considerable numbers of them and settled them about the mouths of these rivers. The co-operation between the piratical Malay Tuankus and the descendants of their imported PROTEGES continued up to the time of the suppression of piracy by the British and Dutch half a century ago. It was from this association with the sea and with coast-pirates that the Ibans became known as the Sea Dayaks by Sir James Brooke; and to this encouragement of their head-hunting proclivity by the Malays is no doubt due their peculiarly ruthless and bloodthirsty devotion to it as to a pastime, rather than (as with the Kayans and other tribes) as to a ceremonial duty occasionally imposed upon them by the death of a chief.