Harlan states that the hulock is found on the Garrau mountains, near Gulpara, in Assam. These apes prefer the adjoining hilly ground to the mountains themselves, which are several hundred feet higher, and exposed to the winds. Their favourite food is a fruit called propul, which is very abundant in this district. A traveller named Owen encountered troops of these animals, from 100 to 150 together, near the Naga and the Abors in the wooded hills to the east of Assam. The noise they made was deafening. On one occasion, when Owen crossed their path, he was threatened by them, and pursued with angry gestures and piercing howls. They had also attacked a native of the district. Snakes of considerable size (_Python reticulatus_) were torn to pieces by them. The wauwau, or, as Martens calls it, the uwa-uwa, appears to live more commonly in pairs than in troops. We learn from Duvaucel that these animals move through the trees with great swiftness, grasping the slenderest and most flexible branches. They swing two or three times to and fro, and then spring with outstretched arms so that the flat surface of the body resists the air like a parachute, and in this way they can pass through spaces of forty feet, and go on for hours without fatigue. Gibbons are generally more capable than other anthropoids of walking upright. Some species, such as the lar, the white-handed, and the slender gibbon, display special dexterity and endurance in maintaining this position. They press the flat soles of their feet upon the ground, turn out their knees and toes, hold their bodies fairly erect, draw the shoulders together, and place their half-bent arms by their sides, with the slender hands hanging slackly down. Others walk with their raised arms crossed above the head. When a gibbon is walking on perfectly flat ground, he sways his arms to and fro like balancing poles. On irregular ground they seize any projection in the way with their outstretched arms, and, holding on to it, swing the body strongly forwards. In this way they make better progress over wide tracks of country, since every such effort enables them to pass more readily over difficult ground. When in great haste, they go upon all fours without closing either fingers or toes. In repose, these animals take a sitting position upon their posteriors, cross their long arms and stare at whatever is before them with an air of indifference. When seated on the branches of trees, they lay hold of the higher branches above them for the sake of security (Fig. 14). In this position some gibbons (_Hylobates lar_, _Hulock_, _Albimanus_) have recently been photographed in the Zoological Gardens, London. Although they are for the most part content with a vegetable diet, gibbons sometimes eat animal food, such as lizards; and Bennet saw a siamang seize and devour one of these animals whole. I do not at this moment remember Huxley’s authority for the statement that gibbons, when they drink, dip the hand in water and