Westernmost and by far the most important of the Outposts is Sumatra, an island four-fifths the size of France, as potentially rich in mineral and agricultural wealth as Java, but with a sparse and intractable population, certain of the tribes, notably the Achinese, who inhabit the northern districts, still defying Dutch rule in spite of the long and costly series of wars which have resulted from Holland's attempt to subjugate them. The unmapped interior of Sumatra affords an almost virgin field for the explorer, the sportsman and the scientist. It has ninety volcanoes, twelve of which are active (the world has not forgotten the eruption, in 1883, of Krakatu, an island volcano off the Sumatran coast, which resulted in the loss of forty thousand human lives); the jungles of the interior are roamed by elephants, tigers, rhinoceroses, panthers and occasional orang-utans, while in the scattered villages, with their straw-thatched, highly decorated houses, dwell barbarous brown men practising customs so incredibly eerie and fantastic that a sober narration of them is more likely than not to be greeted with a shrug of amused disbelief. One who has no first-hand knowledge of the Sumatran tribes finds it difficult to accept at their face value the accounts of the customs practised by the Bataks of Tapanuli, for example, who, when their relatives become too old and infirm to be of further use, give them a pious interment by eating them. When the local Doctor Oslers have decided that a man has reached the age when his place at the family table is preferable to his company, the aged victim climbs a lemon-tree, beneath which his relatives stand in a circle, wailing the deathsong, the weird, monotonous chant being continued until the condemned one summons the courage to throw himself to the ground, whereupon the members of his family promptly despatch him with clubs, cut up his body, roast the meat, and eat it. Thus every stomach in the tribe becomes, in effect, a sort of family burial-plot. I was unable to ascertain why the victim is compelled to throw himself from a lemon-tree. It struck me that some taller tree, like a palm, would better accomplish the desired result. A matter of custom, doubtless. Perhaps that explains why we dub persons who are passé "lemons." Then there are the Achinese, whose women frequently marry when eight years old, and are considered as well along in life when they reach their teens; and the Niassais, who are in deadly fear of albino children and who kill all twins as soon as they are born. Or the Menangkabaus, whose tribal government is a matriarchy: lands, houses, crops and children belonging solely to the wife, who may, and sometimes does, sell her husband as a slave in order to pay her debts.