They are almost unknown to history, for aside from two or three short accounts,[55] based mostly on hearsay, we find no mention of them. The coast natives who knew them by name only had many stories concerning their life and prowess, and one still hears that "the Bila-an are of small stature but agile like monkeys. One may wander for days through their territory without encountering a person and then when in a bad place suddenly see the little people in hundreds swarming down the sides of impassable cliffs. They are always in such numbers that, while they use only the bow and arrow, they are almost sure to exterminate the intruders." As a matter of fact, the Bila-an compare in stature with the coast natives and differ little from them in color, although a few individuals of decidedly lighter cast are met with. [55] BLAIR and ROBERTSON The Philippine Islands, Vol. XLIII, pp. 239, 282-283. Census of the Philippine Islands, 1905. Observations were made on thirty-eight men, but no women could be induced to submit to being measured. The maximum height of the men was found to be 163.6 cm.; minimum 142.3 cm.; with an average of 154.7 cm. The cephalic indices showed 87.8 cm. as the maximum; 74 cm. the minimum; and 80.4 cm. the average. The greatest length-height index was 78.6 cm.; the minimum 62.4 cm. and the average 69.7 cm. From these measurements it appears that the Bila-an are somewhat shorter than the Bagobo; are more short headed, the majority being brachycephalic; while the height from tragus to vertex is about the same in both groups, and both have the crown and back of the head strongly arched. The face[56] is absolutely shorter and relatively broader than in the Bagobo. The forehead is usually high and full, but in about one-third of the individuals measured it was moderately retreating, while in the same proportion the supra-orbital ridges were quite strongly marked. In other features, as well as in hair form, eyes, body form and color, this people conform to the description given of the Bagobo (Plates XLII-XLVIII). [56] Measured from the chin to the hair of the forehead. The greater part of this tribe live far back in the rugged mountains which form the watershed between the Cotabato valley and the Gulf of Davao. Travel through that district is entirely on foot, and is principally along the water courses, so that in going from place to place a person is continually crossing the stream. From time to time dim trails, scarcely worthy of that name, lead from the river's bank almost perpendicularly up the mountain-side or to the summits of high hills, where will be found one or two frail houses (Plate XLIX). The dwellings are never in large groups, and more frequently each house is by itself. From one habitation it is possible to look across the hills and see many others at no great distance, to reach which would necessitate a descent of several hundred feet and an equal climb up to each.